Biomedical subjects

Yan Shen

Publications and source records attributed to Yan Shen.

173 records · Page 10Linked to original sources

PubMed2002

[Analysis of proteins with altered expression in human esophageal squamous cell carcinomas].

BACKGROUND & OBJECTIVE: Esophageal squamous cell carcinoma is characterized by high incidence and high mortality. This study was designed to identify the proteins dysregulated in ECSS by. METHODS: Microdissection of routinely unstained frozen sections was used to procure cancer cells from seven esophageal squamous cell carcinomas, and esophageal epithelial cells from normal tissues adjacent to the tumors. By two-dimensional electrophoresis, protein profiles of normal and cancerous tissues were obtained. Selected proteins with altered expression in tumors were identified through MALDI-TOF-MS. RESULTS: Compared the protein profiles of tumors with those of normal epithelia, 11 proteins were found as dysregulated in tumors. Among them, HSP27 was observed up-expressed and three isoforms of ANNEXIN I were seen down-expressed in cancerous tissues. CONCLUSION: Two-dimensional electrophoresis coupled with mass spectrometry can contribute to rapidly screen dysregulated proteins in human maligancies. Altered expressions of HSP27 and ANNEXIN I were the frequent events in Chinese esophageal squamous cell carcinomas.

Carcinoma, Squamous Cell↗

PubMed2002

[The association of two single nucleotide polymorphisms in PRKCZ and UTS2 respectively with type 2 diabetes in Han people of northern China].

OBJECTIVE: To probe the candidate susceptibility gene (s) of type 2 diabetes in the formal mapping region, 1p36.33-p36.23, in Han people of Northern China using single nucleotide polymorphisms (SNPs). METHODS: 23 SNPs located in 10 candidate genes in the mapping region were chosen from public SNP domain by bioinformatic methods and single base extension (SBE) method were used to genotype the loci in 192 sporadic type 2 diabetes patients and 172 normal individuals to perform case-control study. RESULTS: Among the 23 SNPs, 8 were found to be common in Chinese population. There were statistically different in the allele frequency of 2 SNP, rs436045 in the protein kinase C/xi gene and rs228648 in Urotensin II gene between case and control groups. CONCLUSIONS: The two SNP may be associated with type 2 diabetes in Han people of China, which makes base for further study of the relation between the genes they located with type 2 diabetes.

Alleles↗

PubMed2002

[Single nucleotide polymorphisms in CAPN10 gene of Chinese population and its correlation with type 2 diabetes mellitus in Han people of northern China].

OBJECTIVE: To investigate the distribution of the single nucleotide polymorphisms (SNPs) in CAPN10 gene in Chinese population and their relation with type 2 diabetes mellitus in Han people of Northern China. METHODS: CAPN10 gene was sequenced to detect SNPs in 27 samples of different nationalities in China. 5 SNPs were genotyped with single-base extension (SBE) method to perform case-control study in 156 normal Han people of Northern China and 173 type 2 diabetes and the 3 positive loci reported in the article were performed haplotype analysis. One positive locus was also analyzed with transmission-disequilibrium test (TDT) and sib transmission-disequilibrium test (STDT) in 68 type 2 diabetes pedigrees (377 cases). RESULTS: A total of 40 SNPs were identified in length of 8,936 bp, with an average of 1 in every 223 bp; The SNPs in CAPN10 gene did not distribute evenly and the SNPs in Chinese was different from that reported in American Mexicans. There was no significantly statistical difference in the allele frequency of the 5 SNPs between case and control (P > 0.05), and the haplotype frequencies in the two groups were not much different (P > 0.05). There was no positive results in TDT and STDT analysis (P > 0.05). CONCLUSIONS: The SNP distribution of CAPN10 gene varies with different nationalities. The studied SNPs in CAPN10 gene may not be the major susceptibility ones of type 2 diabetes mellitus in Han people of Northern China.

Alleles↗

PubMed2002

[Annotation of complete genomic sequence of 3p24-p25 478 kb of human DNA].

OBJECTIVE: To annotate the human genome 3p24-p25 478 kb complete sequence. METHODS: The protein-coding genes in the genomic sequence were identified by using ab initio gene finding, homology-based similarity database searching and all or partial mRNA aligning with genomic sequence, and the content feature of the genomic sequence were analyzed by using EMBOSS package. RESULTS: Two known genes SLC6A1 and SLC6A11 were identified; as well as the GC content of this genomic sequence was 47% and 3 putative CpG islands were predicted in the genomic sequence, located in 130,685-131,516 bp, 307,090-307,870 bp and 415,585-416,308 bp, respectively. CONCLUSIONS: The methods, as mentioned above, might be used for annotating the biological information in the genomic sequence, such as gene structure, GC content, CpG island.

Base Sequence↗

PubMed2002

[Functional analysis of the single nucleotide polymorphisms in the PRKCZ gene].

OBJECTIVE: To study the function of 5 single nucleotide polymorphisms (SNPs) of the PRKCZ gene, a susceptibility gene for type 2 diabetes in Han population of North China, in the pathogenesis of the disease. METHODS: Bioinformatic methods and reporter gene activity determination were used to analyze the function of the 5 SNPs. RESULTS: The reporter gene activities of different alleles of 2 SNPs, rs427811 and rs809912, were obviously different, which implies that these 2 SNPs might be susceptibility loci of the disease. CONCLUSION: The PRKCZ gene is further confirmed to be a susceptibility gene for type 2 diabetes in Han population of North China. Two SNPs in the gene play a role in the pathogenesis of the disease by affecting the expression level of PRKCZ gene.

Alleles↗

PubMed2002

[Linkage disequilibrium analysis of the single nucleotide polymorphisms in the PRKCZ gene].

OBJECTIVE: To search for the disease-associated haplotype in the PRKCZ gene, a susceptibility gene for type 2 diabetes in Han population of North China, by case-control study and linkage disequilibrium (LD) analysis using single nucleotide polymorphisms (SNPs). METHODS: SNPs located in the PRKCZ gene were chosen from public SNP domain by bioinformatic methods and single base extension (SBE) method was used to genotype the loci in 173 sporadic type 2 diabetes patients and 152 normal individuals to perform case-control study and LD analysis. Haplotype block were constructed in these populations. RESULTS: Several SNPs in the PRKCZ gene were found to be associated with the disease. The SNPs formed different haplotype block pattern in case and control groups. The frequencies of the haplotypes formed by 5 SNPs were statistically different between the two groups. CONCLUSION: The haplotype formed by 5 SNPs in the PRKCZ gene may be associated with type 2 diabetes in Han population of China, which is confirmed from statistics to be a susceptibility gene for the disease.

Alleles↗

PubMed2002

Orthotopic liver transplantation in treatment of 77 patients with end-stage hepatic disease.

OBJECTIVE: To summarize the experience of human orthotopic liver transplantation (OLTx) in treatment of patients with end-stage hepatic disease and their perioperative management. METHODS: A retrospective analysis was made on OLTx performed in 77 patients from April 1993 to September 2001 in our department included combined liver-kidney transplantation (6 patients) and living related liver transplantation (2). Among them, 76 were adults and 1 was infant (67 males and 10 females). The donors included 75 non-heart beating donors and 2 living related donors. Veno-venous bypass was used only in 45 cases during the operation. immunosuppressive agents consisted of cyclosporine, cellcept, ALG corticosteroids and FK506. RESULTS: The one-year survival rates of grafts and recipients with benign hepatic disease were 75%. The recipients this year are surviving with good function of grafts. CONCLUSION: Liver transplantation is the best therapeutic method for a large number of patients with end-stage hepatic disease in China.

Adolescent↗

PubMed2002

Clinical experience in liver transplantation from an organ transplantation center in China.

OBJECTIVE: To sum up the experience in liver transplantation in a period of ten years at a single center. METHODS: We retrospectively reviewed the clinical records of 120 patients receiving liver transplantation from April 1993 to October 2002. The patients' clinical characteristics, surgical techniques, complications and survival were compared in the phases of 1993-1997 (phase I), 1999 (phase II), and 2000-2002 (phase III). RESULTS: Malignant liver diseases were major indications for liver transplantation in phase I (100%) and II (53.3%), but decreased markedly in percentage in phase III (34.0%). When compared with recipients in phase I and II, the survival of recipients with benign liver diseases in phase III was significantly improved with the 3-month, 6-month and 1-year survival rates of 85.7%, 84.5% and 83.1%, respectively. For patients with malignant liver diseases, the 3-month, 6-month and 1-year survival rates were 87.4%, 81.1% and 46.0%, respectively. The reinfection rate of hepatitis B virus was 24% 12 months after transplantation. With technical refinements, the incidence of postransplantation vascular complications has significantly decreased from 29.4% in phase I and II to 4.9% in phase III. Biliary complications remained one of the major obstacles to long-term survival. No veno-venous bypass was applied in phase III, providing a promising outcome. CONCLUSION: Strict selection of potential recipients, technical refinement, appropriate management of vascular and biliary complications, and prophylaxis of recurrences of hepatitis B and malignant liver diseases are important to obtain long-term survival of patients receiving liver transplantation in China.

Adult↗

PubMed2002

Living related liver transplantation for an infant with biliary atresia.

OBJECTIVE: To sum up the preliminary experience in living related liver transplantation (LRLT). METHODS: A 9-month-old male infant with biliary atresia (BA) who had undergone an unsuccessful Kasai operation was defined as a candidate for LRLT. The donor was his 30-year-old mother. Her lateral lobe of the left liver was transplanted into the infant's body as the graft. The left branches of the portal vein, left hepatic artery and left hepatic vein of the graft were end-to-end anastomosed to the portal vein, hepatic artery proper and hepatic vein of the recipient respectively. Biliary drainage was reestablished via Roux-en-Y operation. RESULTS: The donor retained her liver function within 2 weeks after the operation. Steroid and FK506 were prescribed in immunosuppressive therapy for the recipient. The blood bilirubin level of the infant decreased to normal 2 weeks after operation. No acute rejection occurred. Biliary leakage in the early period after the transplantation was controlled by drainage, and E.coli infection was effectively treated with antibiotics. The donor and recipient are in satisfactory condition to the present. CONCLUSION: LRLT is advisable for children with biliary atresia.

Adult↗

PubMed2001

Functional analyses of human apolipoprotein CII by site-directed mutagenesis: identification of residues important for activation of lipoprotein lipase.

Apolipoprotein CII (apoCII) activates lipoprotein lipase (LPL). Seven residues, located on one face of a model alpha-helix spanning residues 59-75, are fully conserved in apoCII from ten different animal species. We have mutated these residues one by one. Substitution of Ala(59) by glycine, or Thr(62) and Gly(65) by alanine did not change the activation, indicating that these residues are outside the LPL-binding site. Replacement of Tyr(63), Ile(66), Asp(69), or Gln(70) by alanine lowered the affinity for LPL and the catalytic activity of the LPL-apoCII complex. For each residue several additional replacements were made. Most mutants retained some activating ability, but replacement of Tyr(63) by phenylalanine or tryptophan and Gln(70) by glutamate caused almost complete loss of activity. All mutants bound to liposomes with similar affinity as wild-type apoCII, and they also bound with similar affinity to LPL in the absence of hydrolyzable lipids. However, the inactive mutants did not compete with wild-type apoCII in the activation assay. Therefore, we conclude that the productive apoCII-LPL interaction may be dependent on substrate molecules. In summary, our data demonstrate that residues 63, 66, 69, and 70 are of special importance for the function of apoCII, but no single amino acid residue is absolutely crucial.

Apolipoprotein C-II↗

PubMed1999

Molecular Cloning and Expression of the cDNA for Disintegrin from Agkistrodon acutus.

In order to clone novel and valuable genes from natural resources and develop genetic engineering drugs, total RNA was extracted from the venom gland of Agkistrodon acutus by one step method. The cDNAs for low molecular weight metalloproteinase were amplified by RT-PCR and cloned into the pGEMT vector. Their sequence were determined. One of the deduced amino acid sequences included a metalloproteinase and a disintegrin (acugrin) at the carboxyl terminus. This result further confirms that metalloproteinase and disintegrin are derived from the proenzyme of snake venom metalloproeinase. Acugrin exhibits a certain amino acid homology with other disintegrins from snake venoms. Acugrin has four disulfide bonds and a consensus motif RGD. The cDNA for the acugrin was cloned into the plasmid pT7ZZa and expressed in E.coli. ZZ-acugrin fusion protein could strongly inhibit aggregation of platelet induced by ADP and the IC(50) was about 4 nmol/L.

Journal Article↗