Biomedical subjects

Yan Meng

Publications and source records attributed to Yan Meng.

At least 37 records · Page 2Linked to original sources

PubMed2005

High glucose upregulates pantothenate kinase 4 (PanK4) and thus affects M2-type pyruvate kinase (Pkm2).

A new Rattus norvegicus PanK gene was isolated by mRNA differential display from high concentration glucose-stimulated rat, which encodes a human PanK4-like protein with KOG2201 and KOG4584 domain. Proteins that interact with rat PanK4 were identified by the application of the yeast two-hybrid system. One of the components, Pkm2, was found to be associated with rat PanK4 and its two domains under both in vitro and in vivo conditions. Immunofluorescence staining and confocal scanning experiments showed that PanK4 could transiently co-express with Pkm2 in the cytoplasm of HeLa cell and HEK293T cell. These findings suggest that PanK4 interacts with Pkm2 and thereby may modulate the glucose metabolism through regulating the activity of Pkm2.

Amino Acid Sequence↗

PubMed2005

Enhanced perceptual distance functions and indexing for image replica recognition.

The proliferation of digital images and the widespread distribution of digital data that has been made possible by the Internet has increased problems associated with copyright infringement on digital images. Watermarking schemes have been proposed to safeguard copyrighted images, but watermarks are vulnerable to image processing and geometric distortions and may not be very effective. Thus, the content-based detection of pirated images has become an important application. In this paper, we discuss two important aspects of such a replica detection system: distance functions for similarity measurement and scalability. We extend our previous work on perceptual distance functions, which proposed the Dynamic Partial Function (DPF), and present enhanced techniques that overcome the limitations of DPF. These techniques include the Thresholding, Sampling, and Weighting schemes. Experimental evaluations show superior performance compared to DPF and other distance functions. We then address the issue of using these perceptual distance functions to efficiently detect replicas in large image data sets. The problem of indexing is made challenging by the high-dimensionality and the nonmetric nature of the distance functions. We propose using Locality Sensitive Hashing (LSH) to index images while using the above perceptual distance functions and demonstrate good performance through empirical studies on a very large database of diverse images.

Algorithms↗

PubMed2005

A novel mutation at the JK locus causing Jk null phenotype in a Chinese family.

Urea transporters are a group of proteins that facilitate urea movement across biological membranes. Kidd blood group (Jk antigen) and urea transporter of human erythrocytes are carried by the same protein UT-B. To investigate the molecular basis of the Jk null phenotype in the Chinese population, blood samples from Chinese individuals were screened using the 2 mol/L urea solution hemolysis test. Urea and water permeability of erythrocytes membrane was measured by stopped-flow light scattering. Genomic DNA was extracted from lymphocytes. UT-B gene of JKnnu's family was analyzed using genomic PCR by primers designed to cover sequences of all exons and exon-intron boundaries in human UT-B gene. One Jk null subject was found from twenty thousand screened Chinese individuals, and it was confirmed that this individual did not express the erythrocyte urea transporter. Genomic sequence analysis of the Jk null individual showed that there were two point mutations, G-->C, which is novel, and G-->A, at the 3'-acceptor splice site (AG) of intron 5 of UT-B gene. Exon 6 is spliced out in the UT-B transcript due to either of these mutations. Water permeability in Jk null erythrocytes (Pf, -0.00037 cm/s) was significantly lower than that in normal erythrocytes (Pf, -0.00062 cm/s) after HgCl2 incubation, providing evidence for UT-B facilitated water transport in human erythrocytes.

Asian People↗

PubMed2005

[Therapeutic effect and pathology changing of eyelid xanthelasma by Bleomycin A5].

OBJECTIVE: To investigate the effects of Bleomycin A5 on the pathology and ultrastructure of eyelid xanthelasmas. METHODS: Twenty-five randomly selected outpatients from our hospital received 0.2 ml of a 0.4% Bleomycin A5 solution. The drug was directly injected into the tumor every 10 days. In other 5 cases (double up-eyelids xanthelasma), one eye received 0.2 ml of 0.4% Bleomycin A5 injection once and another eye was used as controlling. After one month, operations were performed to remove double up-eyelids xanthelasma tissues, one half of the tissues were investigated by histochemistry; the other half was cut into 1.0 mm x 1.0 mm x 1.5 mm pieces and investigated by electron microscopy. RESULTS: The clinical investigation demonstrated that 25 cases of the Bleomycin treated tumors disappeared completely and the skin color recovered. The eyelids kept their normal morphology and function. Histopathologic investigation of the Bleomycin treated groups showed fibroblasts hyperplasia and sparse foam cells in shallow derma. In the control group, there are large foam cells in shallow layer of derma. The ultrastructure of the treated specimens showed fat droplets decrease in foam cells in contrary to the control group. CONCLUSIONS: Bleomycin A5 can rapidly inhibit the proliferation of foam cells and induce xanthelasma disappearance. Bleomycin A5 is an easy and safe method to treat eyelid xanthelasma and can be widely used in clinical work.

Adult↗

PubMed2005

[Screening susceptibility genes of type 2 diabetes in Chinese population by single nucleotide polymorphism analysis].

OBJECTIVE: To search for the susceptibility variant (s) of type 2 diabetes in the susceptible regions on chr.1 (1p36.23-36.33, 1q24.3-25.1, and 1q42.12-42.13) by genotyping SNP markers in case-control DNA samples and identifying the haplotype associated with type 2 diabetes. METHODS: Totally 124 SNPs in 33 candidate genes in the mapped regions were chosen from public SNP data or identified by sequencing the samples that were used to search for SNP locus. Sequencing method was used to genotype the loci for 236 sporadic type 2 diabetes patients and 152 normal subjects in Northern Han Chinese population. The haplotypes with significant difference were further analyzed. RESULTS: Of 124 SNPs successfully typed, 4 SNPs that showed association with diabetes status were found: rs203849 (P=0.005, OR=1.60) and rs203826 (P=0.016, OR=1.60) located in sAC gene, rs7535528 (P=0.028, OR=1.45) located in PANK4, rs884363 (P=0.043, OR=1.37) located in CASP9 gene. In addition, the frequencies of two combination types from these 4 SNP genotypes were significantly different between case and control groups (P < 0.001). Furthermore, four haplotypes associated with diabetes were found in haplotype analysis of sAC gene. CONCLUSION: sAC, PANK4, and CA SP9 may be associated with type 2 diabetes in Han population in north China, and it seems that the synergetic effect of these genes is responsible for the development of type 2 diabetes.

Adult↗

PubMed2005

[Nuclear localization region in soluble adenylyl cyclase].

OBJECTIVE: To locate the region responsible for nuclear localization of protein sAC. METHODS: The eukaryotic expression vector of vairous sAC deletion mutants were transfected into Hela cells. The localization of each mutant was observed using confocal microscope. RESULTS: For some mutants, the localization of sAC changed. Deletion of some region made it unable to locate in the nuclear. CONCLUSION: It is possible to figure out that the nucleotide region (739-1038 and 1045-1261) take charge of nuclear localization of sAC.

Adenylyl Cyclases↗

PubMed2005

[Research development of Mendelian inherited diabetes].

Diabetes mellitus is a chronic syndrome of abnormal metabolism, determined by interaction of multifactorial genetic and environmental factors. Some specific types of diabetes, such as MODY, Leprechaunism, lipoatrophic diabetes, and Rabson-Mendenhall syndrome, are monogenic forms of diabetes and are inherited as a Mendelian pattern. The article reviews the research development of these Mendelian inherited diabetes will be reviewed.

Diabetes Mellitus, Type 2↗

PubMed2005

[Effects of hypericin associated with light irradiation on human laryngeal squamous cell carcinoma strain Hep-2].

OBJECTIVE: To study effects of hypericin associated with light irradiation on human laryngeal squamous cell carcinoma strain Hep-2. METHODS: Using techniques of tumor cells culture in vitro, Hep-2 cells were exposed to different concentration hypericin as 0.5, 1.0, 2.0, 3.0, 5.0 microg/ml, then 10 minutes 7.5 J/cm2 light irradiation was given after an hour. Other groups Hep-2 culture cells were also exposed to different concentration hypericin as 5.0, 10.0, 20.0, 25.0 microg/ml, without light irradiation. In all groups, contrast groups were set up. And 48 hours later, growth characteristics of Hep-2 cells were studied by morphological observation, fluorescence microscope, MTT assay and flow cytometry. RESULTS: In normal contrast group, Hep-2 cells grew intensively and contacted with each other. However, cells which were treated with hypericin, combination with light irradiation were declined greatly. In higher dose hypericin group, necrosis could be found. MTT assay showed that hypericin associated with light irradiation inhibited growth of laryngeal cell with dose dependence manner. Flow cytometry showed that hypericin with light irradiation could block cell growth at G0/G1 phase, inducing apoptosis of laryngeal cell. Under fluorescence microscope, some sings of cell apoptosis including coagulation of chromatin, fragmentation of nuclei and apoptotic body could be found. CONCLUSION: Human laryngeal squamous cell carcinoma strain Hep-2 can be inhibited and induced into apoptosis by treated with hypericin combination with light irradiation.

Anthracenes↗

PubMed2005

[Potential of human adipose tissue derived adult stem cells differentiate into endothelial cells].

OBJECTIVE: To investigate whether human adipose derived adult stem (hADAS) cells can differentiate into endothelial cells. METHODS: Stem cells were isolated and expanded from adipose tissue and then induced to differentiate into cells of osteogenic, adipogenic and neurogenic lineages in vitro. hADAS cells were induced with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) to endothelial cells differentiation. hADAS cells were intravenously injected into mouse hindlimb ischemic models to test their ability to differentiate endothelial cells in vivo. RESULTS: hADAS cells were easily isolated and expanded in vitro. They had the ability to differentiate into osteogenic, adipogenic and neurogenic lineages. The cells expressed vascular endothelial growth factor receptor-2 (VEGFR-2, Flk1), and expressed endothelial markers when cultured with VEGF and bFGF. In response to local cues, hADAS cells in vivo differentiate into endothelial cells that contributed to neoangiogenesis in hindlimb ischemia models. CONCLUSIONS: Flk1+ hADAS cells have multipotential not only similar to bone marrow mesenchymal stem cells, but also exhibiting characteristics of endothelial progenitor cells. They may be a potential source of endothelial cells for cellular pro-angiogenic therapies.

Adipose Tissue↗

PubMed2005

[Effects of hypericin associated with radiotherapy on human laryngeal squamous cell carcinoma strain Hep-2].

OBJECTIVE: To study effects of hypericin associated with radiotherapy on human laryngeal squamous cell carcinoma strain Hep-2. METHOD: Using techniques of tumor cells culture in vitro, Hep-2 cells were exposed to different concentration hypericin as 0, 1.0, 2.0, 3.0 microg/ml, then 5 Gy radiation were given after an hour. Other groups Hep-2 culture cells were also exposed to different concentration hypericin as 5, 10, 20, 25 microg/ml, and no radiation were given. In all groups, contrast group was set up. And 48 hours later, growth characteristics of Hep-2 were studied by morphological observation, MTT assay and flow cytometry. RESULT: In normal contrast group, Hep-2 cells grew intensively and contacted with each other. And cellular swelling was found when Hep-2 cells were only treated with radiotherapy. When Hep-2 cells were treated with both Hypericin and radiotherapy, more cells swelled and cell number declined greatly. In higher dose Hypericin group, necrosis could be found. MTT assay showed the Hep-2 cells growth was significantly inhibited when treated with both hypericin and radiotherapy. Flow cytometry showed hypericin could block cell growth at G0/G1 phase and induced laryngeal cells into apoptosis whether with radiotherapy or not. But Hep-2 cells only treated with hypericin could not get same powerful effect as combination with radiotherapy. CONCLUSION: Human laryngeal squamous cell carcinoma strain Hep-2 can be inhibited and induced into apoptosis by treated with hypericin combination with radiotherapy.

Anthracenes↗

PubMed2004

Restoration of copper metabolism and rescue of hepatic abnormalities in LEC rats, an animal model of Wilson disease, by expression of human ATP7B gene.

Hepatic abnormalities in Long-Evans Cinnamon (LEC) rats, an animal model of Wilson disease (WD), were restored by the expression of the human ATP7B cDNA under the control of CAG promoter. Expression of ATP7B transcript and protein in the liver of the transgenic rats resulted in the restoration of biosynthesis of holoceruloplasmin and biliary copper excretion. Meanwhile, transgenic rats showed striking improvements in their hepatic abnormalities, i.e., rescue from fulminant hepatitis, late onset of hepatic cholangiofibrosis, suppression of hepatocellular carcinoma and much improved survival rates. Moreover, dramatic decreases were noted both in the levels of hepatic copper and iron in transgenic rats before the occurrence of hepatitis. These results indicated that the human ATP7B product compensated for the deficiency of the endogenous rattus protein and did function in intrahepatic copper transport by secreting copper into the plasma via incorporation into ceruloplasmin and by the excretion of copper into the bile, and that ATP7B is critical to hepatic dysfunctions in WD. This first successful transgenic rescue has important implications for the gene therapy of WD.

Adenosine Triphosphatases↗

PubMed2004

Effect of SNPs in protein kinase C zeta gene on gene expression in the reporter gene detection system.

AIM: To investigated the effects of the SNPs (rs411021, rs436045, rs427811, rs385039 and rs809912) on gene expression and further identify the susceptibility genes of type 2 diabetes. METHODS: Ten allele fragments (49 bp each) were synthesized according to the 5 SNPs mentioned above. These fragments were cloned into luciferase reporter gene vector and then transfected into HepG2 cells. The activity of the luciferase was assayed. Effects of the SNPs on RNA splicing were analyzed by bioinformatics. RESULTS: rs427811T allele and rs809912G allele enhanced the activity of the reporter gene expression. None of the 5 SNPs affected RNA splicing. CONCLUSION: SNPs in protein kinase Cz (PKCZ) gene probably play a role in the susceptibility to type 2 diabetes by affecting the expression level of the relevant genes.

Base Sequence↗

PubMed2004

Gene expression profiling of the bovine gastrointestinal tract.

Basal gene expression levels across the bovine gastrointestinal tract (GI) were examined in an attempt to formulate genetic explanations for the differences in function that are known or thought to exist between the various regions. Gene expression along the tract was studied through the random sequencing of a total of 16 412 clones from seven tissue-specific cDNA libraries spanning its length. The expressed sequence tags (ESTs) within each library were clustered to reduce clone redundancy and obtain longer consensus sequences. BLASTN and BLASTX searches against the NCBI human RefSeq databases were used to find putative matches for the bovine sequences and gene ontology assignments were made. Notable similarities and differences in gene expression were observed among the various compartments of the GI tract of the bovine. Many of the prominent transcripts have yet to be reliably identified and the prominence of others may be worthy of further examination. This collection of ESTs represents an important resource for the future construction of a GI tract specific microarray for further gene expression studies.

Animals↗

PubMed2004

Thiamine pyrophosphate biosynthesis and transport in the nematode Caenorhabditis elegans.

Thiamine (vitamin B1) is required in the diet of animals, and thiamine deficiency leads to diseases such as beri-beri and the Wernicke-Korsakoff syndrome. Dietary thiamine (vitamin B1) consists mainly of thiamine pyrophosphate (TPP), which is transformed into thiamine by gastrointestinal phosphatases before absorption. It is believed that TPP itself cannot be transported across plasma membranes in significant amounts. We have identified a partial loss-of-function mutation in the Caenorhabditis elegans gene (tpk-1) that encodes thiamine pyrophosphokinase, which forms TPP from thiamine at the expense of ATP inside cells. The mutation slows physiological rhythms and the phenotype it produces can be rescued by TPP but not thiamine supplementation. tpk-1 functions cell nonautonomously, as the expression of wild-type tpk-1 in one tissue can rescue the function of other tissues that express only mutant tpk-1. These observations indicate that, in contrast to expectation from previous evidence, TPP can be transported across cell membranes. We also find that thiamine supplementation partially rescues the phenotype of partial loss-of-function mutants of the Na/K ATPase, providing genetic evidence that thiamine absorption, and/or redistribution from the absorbing cells, requires the full activity of this enzyme.

Adenosine Triphosphate↗

PubMed2004

[A two-dimensional reference map of mouse ovary proteins].

OBJECTIVE: To perform a preliminary proteomic analysis of mouse ovaries and to study the protein's function in mouse ovary. METHODS: The two-dimensional gel electrophoresis (2-DE) and matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) were used to analyze mouse ovarian proteome. A 12.5% sodium dodecyl sulfate (SDS) reference gel was generated by immobilized pH gradient isoelectric focusing of mouse ovary proteins in a non-linear gradient (pH 3-10). And GRP78 was selected to perform with immunohistochemistry within mouse ovaries. RESULTS: Based on peptide mass fingerprinting, 52 proteins were identified and classified into seven functional groups: Cell/organism defense and antioxidant, cell signaling/communications proteins, cell structure/motility proteins, metabolism proteins, RNA synthesis processing, protein synthesis and processing, and unclassified proteins. The immunoreactivity of GRP78 was detected in GCs in the follicular, and with during GCs Luteinizing in the menstrual cycle, the protein expression (brown) increased continually and came to a head when ovulation happened. CONCLUSION: This work provides a first step toward the establishment of a systematic ovary protein database and stands as a valuable resource for molecular analyses of normal and pathologic conditions affecting mouse ovaries.

Animals↗

PubMed2003

Protein kinase C/zeta (PRKCZ) gene is associated with type 2 diabetes in Han population of North China and analysis of its haplotypes.

AIM: To identify the susceptible gene (s) for type 2 diabetes in the previously mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotypes of the gene (s) related to type 2 diabetes. METHODS: Twenty three SNPs located in 10 candidate genes in the mapped region were chosen from public SNP domains with bioinformatic methods, and the single base extension (SBE) method was used to genotype the loci for 192 sporadic type 2 diabetes patients and 172 normal individuals, all with Han ethical origin, to perform this case-control study. The haplotypes with significant difference in the gene (s) were further analyzed. RESULTS: Among the 23 SNPs, 8 were found to be common in Chinese Han population. Allele frequency of one SNP, rs436045 in the protein kinase C/zetagene (PRKCZ) was statistically different between the case and control groups(P<0.05). Furthermore, haplotypes at five SNP sites of PRKCZ gene were identified. CONCLUSION: PRKCZ gene may be associated with type 2 diabetes in Han population in North China. The haplotypes at five SNP sites in this gene may be responsible for this association.

Asian People↗

PubMed2003

Anticancer drug resistance of HeLa cells transfected with rat glutathione S-transferase pi gene.

OBJECTIVE: To establish a cytologic expressing system of rat glutathione S-transferase pi (GST-pi) cDNA for detecting the resistance of HeLa cells to anticancer drugs. METHODS: The assessment was made with various anticancer drugs (adriamycin, mitomycin, cisplatinum and vincristine) that showed different cytotoxicities in transfectant HeLa cells with pSV-GT containing rat GST-pi cDNA (HeLa/pSV-GT) or control pSV-neo (HeLa/pSV-neo). Expression levels of GST-pi mRNA in HeLa/pSV-GT and HeLa/pSV-neo were measured by in situ hybridization using Digoxin-labelled cDNA probe. RESULTS: HeLa/pSV-GT expressed significantly high degree of GST-pi mRNA, whereas both HeLa/pSV-neo and HeLa cells had very low expression. Cytotoxicities of HeLa/pSV-GT and HeLa/pSV-neo with 4 anticancer drugs were measured by MTT assay. Drug concentrations for yielding 50% inhibition (IC50) in HeLa/pSV-GT by adriamycin, mitomycin and cisplatinum were 70.13 microg/mL, 10.95 microg/mL and 16.52 microg/mL, respectively. In contrast, IC50 in HeLa/pSV-neo was 10.34 microg/mL, 7.48 microg/mL and 13.70 microg/mL, respectively. The cytotoxicities of vincristine on both HeLa/pSV-GT and HeLa/pSV-neo were not significantly different. CONCLUSIONS: Our findings suggest that HeLa/pSV-GT containing rat GST-pi cDNA is resistant to some anticancer drugs due to overexpression of GST-pi. Also, HeLa/pSV-GT cell line could serve as a useful cytogenetic model for further research.

Animals↗

PubMed2003

[The effect of jiunaoyizhi capsul on signal transduction pathway of SY5Y cell lines].

OBJECTIVE: To observe the effect of Jiunaoyizhi capsul on the signal transduction pathway of SY5Y cell lines and explore the mechanism of the function of the capsul's enhancing neuronal growth. METHOD: Human neuroblastoma was used as cell models and they were divided into control group and experimental group. Supernatant of cell lysate was taken and immunoprecipitation was done with antibodies to proteins related to signal transduction pathway, and the immunoprecipitates were analyzed by Western blotting. RESULT: After treatment with Jiunaoyizhi capsul, expression of Akt/PKB, CREB, P-CREB was clearly increased and expression of cytochrome C decreased more than the control group. CONCLUSION: Jiunaoyizhi capsul can promote expression of some proteins related with signal transduction pathway in SY5Y cell lines. Mechanism of Jiunaoyizhi capsul's enhancing neuronal growth is relevant to expression of some proteins in signal transduction pathway.

Cell Line, Tumor↗