Biomedical subjects

Y Fang

Publications and source records attributed to Y Fang.

At least 73 records · Page 4Linked to original sources

PubMed2001

A novel serine protease SNC19 associated with human colorectal cancer.

OBJECTIVE: To study the structure and function of a novel serine protease gene associated with human colorectal cancer SNC19. METHODS: The cDNA sequence was determined by both manual and automatic sequencing techniques. The full length cDNA sequence was obtained by the 5'-Rapid Amplification of cDNA Ends technique and web-based analysis. Open reading frame analysis and protein function prediction were also performed. Northern blot was used to detect the expression of SNC19 in various human normal tissues and tumor cell lines. Fluorescent in situ hybridization combined with fluorescent R-banding technique was employed to map the SNC19 gene on human chromosome. RESULTS: Full length SNC19 cDNA, size 3152 bp, encodes a protein highly homologous to a mouse serine protease epithin. In normal human tissues, high SNC19 expression levels were observed in the kidney, pancreas, prostate, small intestine and colon; moderate SNC19 expression levels were observed in the placenta, lung, liver, spleen thymus, testis and peripheral blood lymphocytes; and extremely low expression levels were observed in the heart, brain, skeletal muscle and ovary. In tumor cell lines, colorectal cancer cells SW480, SW620, SW1116 and Colo205, breast cancer cell Bcap37 and gastric cancer cells MKN28 and SGC7901 showed high levels of SNC19 expression; cervical cancer cell HeLa-S3, lung cancer PAA, oral epithelial cancer cell KB and lymphoma cell Raji showed moderate levels of SNC19 expression; and tongue squamous cancer cell Tca8113, leukemia cells HL-60, K562, MOLT-4, lung cancer cell A549 and melanoma cell G361 showed very low levels of SNC19 expression. SNC19 was mapped to human chromosome 11q24-25. CONCLUSION: SNC19 encodes a novel human serine protease with 855 amino acid residues. As a novel serine protease associated with human colorectal cancer, the expression of SNC19 in various tissues and cell lines may have very important impact on their phenotypes and biological behaviors.

Amino Acid Sequence↗

PubMed2001

Novel chromosomal alterations detected in primary nasopharyngeal carcinoma by comparative genomic hybridization.

OBJECTIVE: To gain a better understanding of genetic changes in Cantonese nasopharyngeal carcinoma (NPC). METHODS: Comparative genomic hybridization (CGH) was performed on 17 primary nasopharyngeal carcinomas. RESULTS: A novel copy number gain an chromosome 4q and loss of chromosome 1p were found at a high frequency (> 50%). CONCLUSIONS: Current analysis revealed a comprehensive profile of the chromosomal regions showing gain of chromosomes 4q, 12q, and 1q as well as loss of chromosomes 1p, 3p, 11q, 14q, 15q, 13q, Xq, 9q, 10p, 10q, and 16q. Frequently altered loci may encode oncogenes or tumor suppressor genes involved in the development of primary NPC.

Chromosome Aberrations↗

PubMed2001

[Influence of focal adhesion kinase (FAK) on the biological behaviors of human hepatocellular carcinoma cells].

OBJECTIVE: To study the effect of reducing FAK expression on the malignant biological behaviors of FAK-overexpressed hepatocellular carcinoma cell line SMMC-7721. METHODS: FAK expression of different hepatocelluar carcinoma cell lines was detected by Western blot analysis. Antisense plasmid of FAK was constructed and transfected into SMMC-7721. RESULTS: SMMC-7721 expressed much more FAK than did hepatocyte line L02. When transfected with autisense FAK, it showed reduced growth rate and colony formation in soft agar, and the number of cells in S phase was reduced by 15%. The adhesion ability of antisense FAK-transfeected cells was also decreased with no change of integrin expression. CONCLUSION: FAK is overexpressed in the human hepatocellular carcinoma cell line SMMC-7721. Reducing the FAK expression can partly reverse the malignant behaviors of the cell line.

Blotting, Western↗

PubMed2001

[Study of loss of heterozygosity at chromosome 11q13 in nasopharyngeal carcinoma].

OBJECTIVE: To analyze the loss of heterozygosity (LOH) from STS sites at 11q13 in nasopharyngeal carcinoma(NPC). METHODS: Relatively pure tumor tissues were obtained by microdissetion. PCR was used to perform microsatellite analysis of NPC samples using D11S4946, PYGM, D11S449 and INT-2 as primers, which span the MEN-1 gene. RESULTS: Thirty-six of 38 cases studied showed LOH in at least one of the loci analyzed. Among the primers used, D11S4946 had the highest frequency of LOH, (78.8%). The LOH frequency was 51.5% for INT-2, 45.5% for PYGM and 45.7% for D11S449, respectively. CONCLUSION: The high frequency of loss of heterozygosity at 11q13 in NPC implies that there may be some tumor suppressor gene(s) involved in NPC tumorigenesis.

Chromosomes, Human, Pair 11↗

PubMed2001

[Frequent chromosomal gain of 4q and loss of 1p in primary nasopharyngeal carcinoma].

OBJECTIVE: To reveal the genetic changes of nasopharyngeal carcinoma (NPC) in Cantonese. METHODS: Comparative genomic hybridization (CGH) was performed on 17 primary NPC biopsy specimens to find out any gain or loss of genetic material. RESULTS: A novel copy number gain on chromosome 4q and loss of chromosome 1p were found at high frequency (> 50%). The other more common genetic alterations included gain of chromosomes 4q, 12q, and 1q as well as loss of chromosomes 1p, 3p, 11q, 14q, 15q, 13q, Xq, 9q, 10p, 10q, and 16q. CONCLUSION: Current analysis has revealed a comprehensive profile of the chromosomal changes in NPC. Frequently altered loci may encode oncogenes or tumor suppressor genes involved in the development of primary NPC.

Asian People↗

PubMed2001

[Transcatheter arterial embolization in intractable postpartum hemorrhage].

OBJECTIVE: To asses the value of transcatheter arterial embolization treatment in intractable postpartum hemorrhage. METHODS: Fourteen patients of postpartum hemorrhage failed to the drugs treatment were performed transcatheter arterial embolization (TAE). Superselective catheterization to the bilateral uterial arteries or anterior branches of internal iliac arteries was carried out after intubation to single-side femoral artery by Seldinger's technique. When the catheter tip was proved in right place by digital substraction angiography (DSA) techniques, antibiotic solution was poured into arteries and then the arterial embolization with gelfoam particles was followed. RESULTS: All the patients were performed TAE successfully. The duration of TAE was 30-50 minutes [mean (41.8 +/- 6.4) minutes]. Bleeding was found in DSA mostly as diffuse intrauterine flow outward sign from one side or both side of uterial artery branches. After one time of TAE, the vaginal bleeding of all patients was stopped in 3-10 minutes [mean (6.1 +/- 3.6) minutes]. The follow-up showed that all patients had normal menstrual periods in 2-60 months and no serious complications were found. CONCLUSION: With the characteristic of fast homeostasis and less complications, TAE was proved to be an effective method for intractable postpartum hemorrhage.

Adult↗

PubMed2001

[Fine mapping of the loss of heterozygosity for chromosome 1pter-p36.11 in nasopharyngeal carcinoma].

OBJECTIVE: To construct a detailed mapping of the Chromosome 1pter-p36.11 deleted region (63.4 cM) in nasopharyngeal carcinoma (NPC) by polymerase chain reaction-loss of heterozygosity (PCR-LOH) analysis for the further research of NPC-related gene(s). METHODS: Biopsies from 47 cases of NPC patients were studied. DNA extracted from separated cancer cells and their corresponding non-cancer lymphocytes were amplified with PCR, followed by the analysis of LOH and microsatellite instability (MI) for 20 loci spanning Chromosome 1pter-p36.11 region with an average interval of 3.0 cM. RESULTS: 82.2% of NPC cases (37/47) showed at least one loci of LOH. The highest frequency of LOH was found at loci D1S234 on 1p36.13 (50.0%), with the LOH at loci D1S2644 on 1p36.22 slightly less (37.5%). The occurrence of LOH at D1S234 showed no significant difference for the cases at early stage and at advanced stage [60% (9/15) vs 50.0% (8/16) respectively, P > 0.05]. High frequencies of MI were detected at D1S243 on 1p36.33 (37.5%) and D1S199 on 1p36.21 (30.2%). CONCLUSIONS: There are two common deletion regions: one localized at 1p36.13 (D1S234, 2.0 cM) and the other at 1p36.22 (D1S436-D1S2644, 6.3 cM), with a MI loci at D1S199 between them. This suggests that one or more putative tumor suppressor gene(s) related to the early stage of NPC tumorigenesis may be encompassed in this zone.

Adult↗

PubMed2001

[Clinical significance of c-myc oncogene amplification in primary hepatocellular carcinoma by interphase fluorescence in situ hybridization].

OBJECTIVE: To investigate the relationships between c-myc oncogene amplification in primary hepatocellular carcinoma (HCC) and its clinical prognosis. METHODS: To detect c-myc oncogene amplification in 100 cases with primary HCC and in 6 cases with satellite nodes by interphase fluorescence in situ hybridization (FISH). RESULTS: c-myc amplification was detected in 92 of 100 (92%) cases with HCC, 37 of which (37%) showed high copy amplification (HC), 55 (55%) low copy amplification (LC) and 8 (8%) single copy or no amplification (SC). There wasn't statistically different significance between the frequency of c-myc amplification and clinical stage and tumor size, and pathological types (P > 0.05), however, in the 90 follow-up resected cases, the one-year rates of recurrence in HC, LC and SC were 70.6% (24/34), 39.6% (19/48) and 12.5% (1/8) respectively (P < 0.05) but the recurrence rates after more than one year were 14.70% (5/34), 14.6% (7/48) and 0 (0/8) respectively (P > 0.05). Meanwhile, two-year survival rate of patients with HC was significantly lower in comparison with those with LC and SC (P = 0.001). CONCLUSIONS: There is a high frequency of c-myc oncogene amplification in primary HCC and the fact that the patients with HC showed poorer prognosis indicates that the level of c-myc oncogene amplification may be a sensitive index in the prognosis of HCC.

Adult↗

PubMed2001

[Purification and properties of neutral phytase form Bacillus subtilis].

A strain Bacillus subtilis producing neutral phytase was screened from soil. The protein of phytase was purified by HPLC. Optimal pH value and temperature of the phytase for its activity were 7.5 and 55 degrees C, respectively. The Km values of the phytase for dodecasodium phytate under 37 degrees C was 0.19 mmol/L. The molecule weight of the phytase protein was determined as about 45 kD by SDS-PAGE. The N-terminal amino acids sequence of the phytase protein was determined as Lys-His-Lys-Leu-Ser-Asp-Pro-Tyr-His-Phe-Thr by amino acids sequence analysis.

6-Phytase↗

PubMed2001

[The role of fibrinolysis in pathogenesis of middle ears adhesions].

OBJECTIVE: To investigate the role of fibrinolysis in pathogenesis of middle ears adhesions. METHODS: The amount of Tissue-type Plasminogen Activator (tPA) of 28 sections from 6 ears with adhesive otitis media (AOM) and of 22 sections from 6 normal ears was examined by Super Sensitive Biotin-Streptavidin (SSBSA) method. Amount of Fibrin of 11 sections from 3 ears with significant adhesions was compared with that of 12 sections from 3 normal ears. Qualitative analysis of light microscopy with computer-assisted image system was employed. RESULTS: In adhesive ears, tPA stains were negative in 11 of 28 sections and faint positive were 10 of 28 sections, while Fibrin stains were positive in 6 of 11 sections and strong positive were in 3 of 11 sections. In normal ears, tPA stains positive were in 8 of 22 sections and strong positive were 10 of 22 sections, meanwhile, fibrin stains were negative in 8 of 12 sections and faint positive were in 3 of 12 sections. Quantitative analysis showed that the amount of tPA was 16.70 +/- 5.11 and 39.84 +/- 6.26 in ears with AOM and normal ones respectively (P < 0.05). CONCLUSION: In adhesive ears the amount of tPA was less than that in the normal ears, whereas, the amount of Fibrin was greater in ears with AOM than that in normal ears. It indicates that fibrinolysis involved in the process of adhesion formation of AOM, which may acts as a key factor.

Fibrin↗

PubMed2000

BtCH(2)TMS-assisted homologation of carboxylic acids: A safe alternative to the arndt-eistert reaction

One-carbon homologation of carboxylic acids is achieved by (i) treatment of an acyl chloride with 1-[(trimethylsilyl)methyl]-1H-1,2, 3-benzotriazole (BtCH(2)TMS) (1) to afford N-(acylmethyl)benzotriazoles 3a-f, followed by (ii) conversion of 3a-f with triflic anhydride into RC(OTf)=CHBt 4a-f, and (iii) the subsequent reaction of 4a-c with NaOCH(3) followed by 1N HCl to afford esters RCH(2)CO(2)R' 7a-c in overall yields of 50-70%. For the aliphatic compounds 5d-f, treatment of 5d-f with p-toluenesulfonic acid followed by TBAF/THF afforded acids RCH(2)COOH 7d-f.

Journal Article↗

PubMed2000

Using a phage display library to identify basic residues in A-Raf required to mediate binding to the Src homology 2 domains of the p85 subunit of phosphatidylinositol 3'-kinase.

Src homology 2 (SH2) domains are found in a variety of cytoplasmic proteins involved in mediating signals from cell surface receptors to various intracellular pathways. They fold as modular units and are capable of recognizing and binding to short linear peptide sequences containing a phosphorylated tyrosine residue. Here we show that each of the SH2 domains of the p85 subunit of phosphatidylinositol 3-kinase selects phage displayed peptide sequences containing the core (L/I)-A-(R/K)-I-R. The serine/threonine kinase A-Raf, containing the sequence LQRIRS, is associated with the p85 protein in both quiescent and growth factor stimulated cells. This suggests that p85 and A-Raf exist in a protein complex in cells and that complex formation does not require growth factor stimulation. We also show that p85 and A-Raf can bind directly to each other in vitro and that this interaction is mediated in part by the p85 SH2 domains. Further, the p85 SH2 domains require at least one of four distinct basic-X-basic sequence motifs within A-Raf for binding. This is the first description of a phosphotyrosine-independent SH2 domain interaction that requires basic residues on the SH2 ligand.

3T3 Cells↗

PubMed2000

Discoidin domain receptor 1 functions in axon extension of cerebellar granule neurons.

In the developing cerebellum, granule neuron axon outgrowth is a key step toward establishing proper connections with Purkinje neurons, the principal output neuron of the cerebellum. During a search for genes that function in this process, we identified a receptor tyrosine kinase discoidin domain receptor 1 (DDR1) expressed in granule cells throughout their development. Overexpression of a dominant-negative form of DDR1 in immature granule cells results in severe reduction of neurite outgrowth in vitro, in dissociated primary culture, and in vivo, in organotypic slices of neonatal cerebellum. Granule cells that fail to extend axons are positive for differentiation markers such as TAG-1 and the neuron-specific class III beta-tubulin, suggesting that development is affected after granule cells commit to terminal differentiation. DDR1 activation appears to be mediated by its ligand, collagen, which is localized to the pial layer of the developing cerebellum, thereby leading to granule cell parallel fiber extension. Our results therefore indicate that collagen-DDR1 signaling is essential for granule neuron axon formation and further suggest a unique role of pia in cerebellar cortex histogenesis.

Animals↗

PubMed2000

Natural animal coloration can Be determined by a nonfluorescent green fluorescent protein homolog.

It is generally accepted that the colors displayed by living organisms are determined by low molecular weight pigments or chromoproteins that require a prosthetic group. The exception to this rule is green fluorescent protein (GFP) from Aequorea victoria that forms a fluorophore by self-catalyzed protein backbone modification. Here we found a naturally nonfluorescent homolog of GFP to determine strong purple coloration of tentacles in the sea anemone Anemonia sulcata. Under certain conditions, this novel chromoprotein produces a trace amount of red fluorescence (emission lambda(max) = 595 nm). The fluorescence demonstrates unique behavior: its intensity increases in the presence of green light but is inhibited by blue light. The quantum yield of fluorescence can be enhanced dramatically by single amino acid replacement, which probably restores the ancestral fluorescent state of the protein. Other fluorescent variants of the novel protein have emission peaks that are red-shifted up to 610 nm. They demonstrate that long wavelength fluorescence is attainable in GFP-like fluorescent proteins.

Amino Acid Sequence↗

PubMed2000

Determination of thiols following their separation by CZE with amperometric detection at a carbon electrode.

The amperometric detection (AD) employing a carbon disk electrode as a working electrode to determine the thiol compounds, including cysteine (CYS), glutathione (GSH), 6-thiopurine (TP), and methimazole (MMI), following their separation by capillary zone electrophoresis (CZE) is described in this paper. The detection potential was chosen at +1100 mV and all analytes exhibit good response at this potential on the carbon disk electrode. The reproducibility, linearity, and recovery were evaluated under the optimum conditions. The four analytes can be baseline resolved within 20 min and the detection limits reached about 10(-6) mol/l of magnitude. The method was applied to the separation and determination of the actual thiol samples and the analytical results were satisfactory.

Carbon↗

PubMed2000

Spectroscopic studies of copper(II) and iron(II) complexes of adriamycin.

The complexes of adriamycin (ADM) with Cu(II) and Fe(II) have been studied by visible absorption, circular dichroism (CD) and fluorescence spectra, respectively. In Tris buffer at pH 7.0, either metal ions forms a single species with adriamycin: Cu(ADM)2 or Fe(ADM)3. Interaction of these two complexes with various biological molecules has been examined. It is shown that some amino acids, glutathione and albumin are able to remove the Cu(II) ion from Cu(II)-ADM complex, releasing the free drug. However, Fe(II)-ADM keeps in an undissociated form under the same conditions. The possibility of Fe(II) ADM as a new alternative drug has been discussed.

Antibiotics, Antineoplastic↗

PubMed2000

Applications of capillary electrophoresis with electrochemical detection in pharmaceutical and biomedical analyses.

As a high efficiency separation technique, capillary electrophoresis has been widely used in various fields of analytical science. This review discusses the applications of electrochemical detection systems combined with capillary electrophoresis in pharmaceutical and biomedical analysis. These detection methods mainly involve amperometric detection but also include conductivity detection and potentiometric detection. Its applications in the field are divided into six parts, including catechol compounds, thiols, amino acids and peptides, carbohydrates, general pharmaceuticals, and other related compounds. A relatively detailed discussion is described for each compound under the current studied. On this basis, we have suggested several conceivable directions for capillary electrophoresis with electrochemical detection in the future.

Electrochemistry↗

PubMed2000

Detection of sequence variability of the collagen type IIalpha 1 3' variable number of tandem repeat.

The variable number of tandem repeat (VNTR) 3' of the collagen type II (COL2A1) gene has been shown to be highly variable with a complex molecular structure. In a previous pilot experiment we observed discordance between methods to genotype this informative marker. To further investigate the extent and molecular nature of this discordance, we genotyped a random sample of 207 Caucasian individuals with two genotyping methods and sequenced new alleles. We compared single-strand (SS) analysis, which is based on detection of size differences between the different alleles, and heteroduplex analysis (HA), which is sensitive to both size and sequence differences. Overall, 26% of discordance between the two methods was detected. Approximately two thirds of this discordance was caused by subdivision of SS-alleles 13R1 and 14R2 into HA-alleles 4A + 4B and 3B + 3C, respectively. Sequence analysis of the COL2A1 VNTR alleles 4B and 3C showed that these alleles differed in sequence, but not in size, from already described SS-alleles, which explains why they escape detection by SS. The 4B allele is a frequent allele in the population (14%) and is, therefore, important to distinguish in association studies. We conclude that HA is a reliable method when the described optimized electrophoretic conditions are used. HA is a sensitive genotyping method to document allelic diversity at this locus, which can distinguish more alleles compared to the SS method.

Aged↗