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Ya-Li Zhang

Publications and source records attributed to Ya-Li Zhang.

At least 37 records · Page 2Linked to original sources
PubMed2003

[Cloning, sequencing and bioinformatics analysis of a new tumor suppressor gene ndr2 from mouse].

BACKGROUND & OBJECTIVE: Ndr2 (N-myc down stream regulator) gene in human is a new gene cloned with the human adult whole brain cDNA as template in 1999, which accession number is AF159092 in GenBank. Locating backward position of the N-myc gene in human chromosome, this gene was named Ndr2 gene. The previous experimental results showed Ndr2 gene probably is a tumor suppressor gene. To research the function of Ndr2 gene, the authors cloned the genomic sequence of ndr2 from mouse. METHODS: To clone Ndr2 genomic sequence by reverse transcription-polymerase chain reaction(RT-PCR) with the mouse genome library as template; automatic sequencing was performed using 310 Genetic Analyzer; homogeneous analysis was made using GenBank BLAST; open reading fragment(ORF) analysis was made using PC Gene and ORF Finder; domain analysis was made using ProDom system. RESULTS: A fragment (about 3310bp,identified by agarose gel electrophoresis) was obtained using RT-PCR with the mouse genome library as template. The fragment was cloned in pMD18-T vector. BLAST analysis showed that the sequence was highly homogeneous (with the homogeneity rate of 91.4%) with Ndr2 gene in human and non-homogeneous with genomic sequence database in mouse. ORF analysis showed that there was a complete coding region in it, which including 8 extrons and 7 introns; it can interpret a protein containing about 200 amino acid residuals. ProDom analysis showed there was a domain like acyl carrier protein(ACP) in it. CONCLUSION: The authors cloned Ndr2 gene in mouse and proved that the sequence is a new genome sequence in mouse genomic sequence database. At present, the genome sequence has been submitted to GenBank(the accession number: AY151387).

Adaptor Proteins, Signal Transducing↗
PubMed2003

[A novel method for fabrication of tissue microarray].

BACKGROUND & OBJECTIVE: Tissue chip (tissue microarray, TMA) is one of the most important biochip techniques, just following the gene chip and the protein chip, which is one of the most important functional genomics and proteomics research methods in the post-genomic era. However, the present TMA technology has certain shortcomings, such as lack of advanced instruments, tedious procedure, and low sampling accuracy, etc. This new method was designed to improve the technology of TMA. METHODS: A common microscope was installed with a special holing needle, a sampling needle, and a proper box to fix paraffin blocks on the microscope carrier. With the precise mechanical control of microscope, the holing procedure on the recipient paraffin blocks and sampling procedure of core tissue biopsies were performed with the re-equipped microscope. The precise observation and localization of sampling regions were also performed using the same microscope equipped with a stereoscope. RESULTS: The new method simplified TMA procedure, and the whole process of holing, locating, and sampling was performed with the same instrument on the same platform. The single-use holing and sampling needles were first applied to maintain higher accuracy and to avoid the tissue remains and contamination among different samples. And high-qualified tissue chips of colorectal tumors were produced successfully by the new method. CONCLUSION: Using the re-equipped common microscope to fabricate tissue microarrays is a simple, reliable, cost-effective,and well-applicable technique.

Histocytological Preparation Techniques↗
PubMed2003

[Role of eukaryotic initiation factor-4E (eIF-4E) in regulation of expression of NF-kappaB and its subsequent influence on transcription and activity of heparanase in human colon adenocarcinoma cell line].

BACKGROUND & OBJECTIVE: Recent studies have revealed that some transcription factors may be translationally regulated by eukaryotic initiation factor-4E (eIF-4E) in human cancer. These modifications in the expression levels of the key transcription factors will alter the expression of some malignancy-related gene products at the transcriptional levels. The current study was designed to investigate the effect of eIF-4E on the expression and activity of NF-kappaB and observe how the activity level of NF-kappaB contributes, as a secondary effect, to the transcription of heparanase in human colon adenocarcinoma LS-174T cells. METHODS: In order to repress the expression of eIF-4E, a 20-mer antisense oligodeoxynucleotide (ASODN) targeted against the translation start site of eIF-4E mRNA was transfected into human colorectal cancer cell line LS-174T via liposome reagent, followed by assessment of the activity and the protein expression of NF-kappaB by an electrophoretic gel mobility shift assay (EMSA) and Western blot analysis respectively. The alterations of heparanase expression were examined by RT-PCR and Western blot analysis, and heparanase activity in LS-174T cells was measured by specific enzymatic activity test using radiolabeled heparan sulfate as the substrate and gel filtration chromatography for the analysis of the degradation product. RESULTS: The 20-mer ASODN against eIF-4E specifically and significantly inhibited eIF-4E expression at both transcriptional and translational levels, and the repression of eIF-4E gene expression was correlated with decreased expression levels and activity of NF-kappaB protein. Furthermore, this down regulation of the ubiquitous transcription factor NF-kappaB led to reduced transcription of the heparanase gene, and the transfected cells also showed a considerable decrease in heparanase protein and activity. CONCLUSION: These results suggest that eIF-4E play an important role in translational regulation of NF-kappaB expression in LS-174T cells.NF-kappaB is an essential factor in the regulatory mechanisms of heparanase gene transcription, and the suppressed NF-kappaB activity in LS-174T cells may significantly reduce the transcriptional expression of heparanase that consequently leads to decreased heparanase protein expression and enzymatic activity.

Adenocarcinoma↗
PubMed2003

[Construction of the attenuated Salmonella typhimurium strain expressing Helicobacter pylori conservative region of adhesin antigen].

To construct a non-resistance and attenuated Salmonella typhimurium strain which expresses conservative region of adhesin(AB) of Helicobacter pylori(Hp). The AB gene was amplified by PCR and inserted into the expression vector pYA248 containing asd gene and was introduceded into the delta Cya, delta Crp, delta Asd attenuated Salmonella typhimurium strain by twice transformations, which is a balanced lethal recombinant. Bridged ELISA method was used to measure AB expressed in sonicate and culture supernatant. According to Meacock's way and growth curve, stability of the recombinant is evaluated. Semi-lethal capacity test was used to evaluate the safty of recombinant. Results showed S. typhimurium X4072(pYA248-AB) was constructed successfully, recombinant X4072(pYA248- AB) content of supernatant serum was higher than that of thallus lytic liquor confirmed by bridged ELISA, and after recombinant pYA248- AB cultured 100 generation without selection pressure, all the recombinant germ selected randomly can grow, and the AB antigen was positive by ELISA detection. The growth curve of the recombinant germ showed that the growth state of X4072(pYA248) and X4072(pYA248- AB) were coincidence on the whole, and the survival rate of C57BL/6 was still 100%, 30 days after taking X4072(pYA248- AB) 1.0 x 10(10)cfu. orally. Non-resistance S. typhimurium X4072(pYA248- AB) was constructed successfully. The recombinant plasmid was stable indicated by in vitro experiment. And the recombinant strain was safe confirmed by animal experiment. This live vaccine strain is worthy to be considered as a new live oral vaccine candidate against Hp infection.

Adhesins, Bacterial↗
PubMed2002

Early diagnosis for colorectal cancer in China.

AIM: To review the present studies on early diagnosis of colorectal cancer. METHODS: The detective rate for early cancer is 1.7%-26.1% based on various statistical data, with much higher detective rate in endoscopy. Since early cancer means invasion involved in the mucosa or submucosa, the diagnosis can only be made when the invasive depth is identified. Pathological tissue materials from both surgical operation or endoscopic resection are suitable for early cancer evaluation. RESULTS: Incidence of polyp malignancy is 1.4%-20.4%. The various constitutive proportion of polyps may explain the different rates. Malignant incidence is higher in adenomatous polyps, that for villous polyps can reach 21.3%-58.3%. Type II early stage of colorectal carcinoma is rarely reported in China. It is shown that majority of them were not malignant, most of type IIa being adenoma or hyperplasia, and IIb being inflammatory and IIc might be the isolated ulcers. The occurrence of malignancy of type II is far lower than that of polypoid lesion. In China, the qualitative diagnosis and classification of neoplasm generally adopted the WHO standard, including surgical excision or biopsies. There is impersonal evaluation between colorectal pre-malignancy and cancer. The former emphasizes the dysplasia of nuclei and gland, while the latter is marked with cancer invasion. Diagnosis of early stage colorectal cancer in endoscopy is made with too much caution which made the detective rate much lower. Mass screening for asymptomatic subjects and follow-up for high risk population are mainly used to find the early stage colorectal cancer in China. Fecal occult blood test is also widely made as primary screening test, galactose oxygenase test of rectal mucus (T antigen), fecal occult albumin test are also used. The detective rate of colorectal cancer is 24-36.5 per 105 mass population. CONCLUSION: Although carcinoma associated antigen in blood or stool, microsatellite DNA instability for high risk familial history, molecular biology technology for stool oncogene or antioncogene, telomerase activity and exfoliative cytological examination for tumor marker, are utilized, none of them is used in mass screening by now.

China↗
PubMed2002

Establishment of dextran sulfate sodium-induced ulcerative colitis model in mice.

OBJECTIVE: To establish a model of ulcerative colitis in mice. METHODS: The mice were given 5% dextran sulfate sodium (DSS) solution freely for 7 consecutive days after which distilled water was given in stead for another 10 d, to complete one cycle of whole treatment plan that consisted of 4 such cycles. The symptoms were observed daily. At the end of the first and the fourth cycle respectively, the mice were killed for examining the whole colon under anatomic microscopy and serial tissue sections were prepared for histological observation. RESULTS: The symptoms observed in the mice including hematochezia diarrhea and loss of the body weight were similar to those of ulcerative colitis patients. Histological examination revealed infiltration of neutrocytophilia and lymphocythemia, with loss of integrity of the colon mucosa in the gland. CONCLUSION: This mouse model of ulcerative colitis can be easily induced and readily applied in various studies of ulcerative colitis.

Animals↗
PubMed2002

Effect of protein kinase C on multidrug resistance of multidrug-resistant colorectal cancer LoVo/Adr cells.

OBJECTIVE: To observe the effect of protein kinase C (PKC) on the multidrug resistance of multidrug-resistant colorectal cancer LoVo/Adr cells and explore the mechanism. METHODS: The changes of PKC activity in LoVo/Adr cells in response to treatment with staurosporine (SP) and phorbol-12-myristate-13-acetate (PMA) were detected by way of 32P incorporation. The effect of PKC on adriamycin uptake in LoVo/Adr cells was detected by flow cytometry. Reverse transcriptase-PCR was utilized to observe the effect of PKC on mdr1 gene expression. RESULTS: PMA evinced bi-directional regulation of PKC activity in LoVo/Adr cells, and SP significantly inhibited membrane and cytosol fraction of PKC activity. Preincubation with PMA for 30 min caused the uptake of adriamycin to decrease significantly, but when the preincubation was prolonged to 24 h, significant increase occurred in adriamycin uptake. Neither PMA nor SP, however, could affect the expression of mdr1 gene. CONCLUSION: PKC regulates multidrug resistance of the cells through mechanisms other than regulation of mRNA level of mdr1 gene.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Detection of soluble tumor necrosis factor-p55 levels in the serum and ascitic fluid of patients with hepatocellular carcinoma.

OBJECTIVE: To examine soluble tumor necrosis factor receptor-p55 (sTNFR-p55) levels in the serum and ascitic fluid and investigate the significance of this examination in assessment of the clinical status of patients with primary hepatocellular carcinoma (HCC). METHODS: Enzyme-linked immunosorbent assay (ELISA) was used to examine sTNFR-p55 levels in the serum and ascitic fluid in 25 patients with HCC and 25 with liver cirrhosis (LC). RESULTS: sTNFR-p55 levels in the serum and ascitic fluid in patients with HCC were significantly higher than those in patients with LC and controls (P=0.001). No significant difference was found between LC and the control in terms of serum sTNFR-p55 levels (P=0.19). Positive correlation was observed between sTNFR-p55 levels in the serum and in ascitic fluid of patients with HCC and LC (r=1.000, P<0.001). Logistic regression revealed that in patients with HCC, serum sTNFR-p55 levels were positively correlated with TBil and AFP in the peripheral blood (r=0.524, P=0.01 and r=0.234, P=0.03, respectively). CONCLUSIONS: Increased sTNFRs-p55 levels in the serum and ascitic fluid reflect abnormal immune status of the patients with HCC and help predict the development of tumor.

Adult↗
PubMed2002

Conservative region of the genes encoding four adhesins of Helicobacter pylori: cloning, sequence analysis and biological information analysis.

OBJECTIVE: To clone the conserved regions of the genes encoding the 4 adhesins (BabA, AlpA, AlpB and HopZ) of Helicobacter pylori (H. pylori) and analyze their sequences and biological information, thus facilitating further research in the molecular mechanism and immunogenicity of H. pylori adhesins. METHODS: Common conserved region (designated as CB) was identified from the confirmed sequences (by ANTHEPROT V4.3c software package) of the 4 adhesin proteins. Their DNA sequences were deduced, according to which primers specific to CB were designed for subsequent PCR, and the products were inserted directionally into pET-22b(+) vector to construct recombinant clones of the conserved region. The DNA sequences were determined with the basic local alignment sequence tool (BLAST) and the biological properties analyzed with ANTHEPROT V4.3c software package. RESULTS: The recombinant plasmid containing the CB sequence was constructed. DNA sequencing showed an open reading frame of 588 bp in length, encoding 195 amino acids. The homogencity of conservative region of the 4 adhesion genes was above 50%. The corresponding protein possessed a relative molecular mass (Mr) of 22 500 as predicted by ANTHEPROT V4.3c software prediction, with excellent antigenicity and hydrophobicity. There were 836 767 sequences analyzed with BLAST, in which those with homogencity of 40% with the identified CB sequence were categorized into H. pylori sequences. CONCLUSION: There are conservative regions in the 4 adhesin genes with similar homogencity, suggesting similar molecular basis for adhesion of the adhesins. Biological information analysis indicates that CB has excellent immunogenicity and strict species specificity.

Adhesins, Bacterial↗
PubMed2002

Preparation and identification of monoclonal antibodies against human brain-derived neurotrophic factor.

OBJECTIVE: To prepare monoclonal antibodies (mAbs) against human brain-derived neurotrophic factor (BDNF). METHODS: BALB/C mice were immunized with purified BDNF protein in conjunction with acid-treated Salmonella (antigen:thallus=1:5), and mAbs were subsequently derived by hybridoma technique. RESULTS: Three hybridoma cell lines secreting anti-BDNF mAbs were obtained, designated as B1, B2 and 4D1 respectively and all categorized into IgG1 subtype. The titers of the mAbs in the ascitic fluid of the rats ranged from 1x10(6) to 1x10(5), and their relative affinities were B2>B1>4D1. CONCLUSION: mAbs against BDNF are successfully prepared, which can be instrumental for further study of the expression and distribution of BDNF in vivo, and the detection of BDNF produced by genetic engineering.

Animals↗
PubMed2002

[Effect of Helicobacter pylori infection on gastric mucosal cell proliferation in Mongolian gerbils].

OBJECTIVE: To explore the mechanism that Helicobacter pylori (H. pylori) infection can induce adenocarcinoma in Mongolian gerbil model with long-term H. pylori infection. METHODS: Mongolian gerbil model with long-term H. pylori infection was established by inoculation H. pylori NCTC 11637 strain, and immunohistochemical straining and in situ hybridization were employed to observe changes in gastric mucosal cell proliferation due to H. pylori infection. RESULTS: Mongolian gerbil model with long-term H. pylori infection was successfully established. Immunohistochemical staining of 5'-bromodeoxyuridine (BrdU) and proliferating cell nuclei antigen (PCNA) showed that H. pylori infection induced the increase in gastric mucosal cell proliferation (P<0.05), and in situ hybridization of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) revealed elevated expressions of EGF mRNA and EGFR mRNA with time passage after H. pylori infection (P<0.05). CONCLUSION: H. pylori inoculation can induce abnormality in gastric mucosal cell proliferation, which is instrumental for the progression from chronic gastritis to glandular atrophy, intestinal metaplasis and ultimately to atypical hyperplasia. The abnormal expressions of EGF and EGFR may be the key element for abnormality of gastric mucosal cell proliferation.

Animals↗
PubMed2002

[Survey on drug resistance to ciprofloxacin in common pathogenic bacteria].

OBJECTIVE: To obtain primary knowledge of drug resistance to ciprofloxacin in the common pathogenic bacteria in this hospital thereby to bring the situation under control. METHODS: A total of 3 800 strains of pathogenic bacteria were isolated from in-patients from 1997 to 2000, and drug resistance of these strains to ciprofloxacin was examined. RESULTS: During the past 4 years, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis were found to be highly resistant to ciprofloxacin with the rates still on the rise from 50%, 25.6% and 40.3% in 1997 to 62.2%, 53.4% and 63.6% respectively in 2000. Over 40% of Escherichia coli, Klebsiella pneumoniae and Enterobacter were resistant to ciprofloxacin and the percentages for Pseudomonas aeruginosa and Acinetobacter reached 31.1% to 34.0% in 2000. Among the 189 strains of the pathogenic bacteria isolated from patients with sustained infection in our hospital in 2000, over 70% of Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis were identified as having resistance to ciprofloxacin. CONCLUSION: The percentages of common pathogenic bacteria that are resistant to ciprofloxacin have been considerably high and tend to increase further. Ciprofloxacin abuse needs to be given appropriate attention.

Anti-Infective Agents↗
PubMed2002

[Endoscopic diagnosis and treatment of the early-stage malignant colorectal polyp and follow-up study].

In the past 20 years we have performed endoscopic removal of colorectal polyps in 4 000 cases, and thorough histological examination of the removed polyps identified 121 cases of early-stage malignant polyp. According to the depth of malignant invasion and whether malignant remnants were present after the initial surgical removal, conservative treatment or radical operation was implemented. During the follow-up study, endoscopy was performed once each year in all the patients with malignancies. No recurrence was found in the 33 patients with mucosa cancer or in the 27 patients with type I submucosa cancer who did not receive radical operation due to absence of malignant remnants or in the 38 patients with type II submucosa cancer who had the radical operation. Relapse occurred in 1 patient with malignant remnant and in another 3 cases of type II submucasa cancer without radical operation.

Adult↗
PubMed2002

[Construction and application of colorectal polyp database].

OBJECTIVE: To study the construction and application of computerized database of colorectal polyp in the clinical management and research of this disease. METHOD: A colorectal polyp database and its management system was constructed on the basis of Microsoft Access 2000. Clinical, endoscopic and pathological data, which went through standardized and elemental processing, of 2 627 cases (4 850 records) of colorectal polyp collected from 1990 to 2000 in Nanfang Hospital was entered into this database. RESULTS: Using this new database, the information on the population and age distribution, location and clinical features of colorectal polyps were obtained. Comparative study of the clinical and pathological findings in the cases, evaluation of the therapeutic effects, statistical review of the identification of the polyp and its canceration in the previous years as well as the analysis of other relevant factors were successfully accomplished, which greatly facilitated the follow-up study of some chosen cases that may be of clinical significance. CONCLUSIONS: Applications of modern informatics and computer technology greatly facilitates case management and clinical research of colorectal polyps, and standardized and elemental processing of the clinical data offers a new possibility for easy case information management.

Colonic Polyps↗
PubMed2002

[Study on the cloning, expression and the immunogenicity of helicobacter pylori heat shock protein 60 gene].

OBJECTIVE: To construct a recombinant strain of bacteria expressing heat shock protein of (Hsp) Helicobacter pylori (Hp) and study the immunogenicity of Hsp60. METHODS: PCR amplification of Hsp60 DNA was performed before it was inserted into the prokaryotic expression vector pET-22b(+) to transform BL21(DE3) E.coli strain. Hsp60 expressed by the recombinant E.coli was collected and purified for immunogenicity assessment in mice. RESULTS: DNA sequence analysis showed identical DNA sequence of Hsp60 thus produced to that published in Genbank. Accounting for a ratio of 27.2% among the total protein production in the bacterium, recombinant Hsp60 protein was recognized by the serum from Hp-infected patients and produced corresponding antibody in Balb/c mice in response to immunization. CONCLUSION: Recombinant Hsp60 protein can be used potentially as a vaccine for controlling and treating Hp infection.

Bacterial Proteins↗
PubMed2002

[Diagnosis of hepatocellular carcinoma with bone metastasis using fine needle aspiration biopsy: report of 2 cases].

The clinical presentations and imaging characteristics of hepatocellular carcinoma (HCC) are usually various and complex. This article reported 2 cases of HCC with the initial symptoms being bone metastasis that did not exhibit typical clinical manifestations or distinct feature in liver imaging, without elevated serum alpha-fetoprotein. The diagnoses were certified by fine needle aspiration biopsy, which is recommended for differential diagnosis in cases of complex HCC with bone metastasis, to avoid liver biopsy and surgical bone biopsy.

Adult↗
PubMed2001

Preparation of anfi-CD3 and anti-IgM&mgr; chain bispecific antibody by cell fusion.

OBJECTIVE: To prepare anti-CD3 and anti-Igm&mgr; chain bispecific antibody (BsAb) by means of cell fusion and assess the stability and activity of the hybrid hybridoma. METHODS: Mouse hybridoma cell line secreting anti-human CD3 monoclonal antibody (mAb) was trans formed into HAT-sensitive cells by 8-azaguanine, which was subsequently transfected by plasmid pCDaA3 containing neoR marker gene via FuGENETM6. The resulted mutant phenotype, named alphaCD3 HATs G418R, was fused with the hybridoma producing anti-IgM&mgr; chain mAb, and enzyme-linked immunosorbent assay and flow cytometry were employed to identify the fusion cells producing the target BsAb. RESULTS: Six rounds of cell fusion was performed and a total of l 080 wells inoculated, yielding 5 hybrid hybridoma cell lines. Two of the 5 cell lines were subcloned and continuously cultured in vitro for 2 months without losing their capability to secrete BsAb. CONCLUSION: Cell fusion technique can be utilized to prepare BsAb-producing hybrid hybridoma that has similar stability and activity to its parent hybridoma.

Journal Article↗