Biomedical subjects

F Ye

Publications and source records attributed to F Ye.

At least 37 records · Page 2Linked to original sources

PubMed2001

Flow cytometric platform for high-throughput single nucleotide polymorphism analysis.

We have developed a rapid, cost-effective, high-throughput readout for single nucleotide polymorphism (SNP) genotyping using flow cytometric analysis performed on a Luminex 100 flow cytometer. This robust technique employs a PCR-derived target DNA containing the SNP, a synthetic SNP-complementary ZipCode-bearing capture probe, a fluorescent reporter molecule, and a thermophilic DNA polymerase. An array of fluorescent microspheres, covalently coupled with complementary ZipCode sequences (cZipCodes), was hybridized to the reaction products and sequestered them for flow cytometric analysis. The single base chain extension (SBCE) reaction was used to assay 20 multiplexed SNPs for 633 patients in 96-well format. Comparison of the microsphere-based SBCE assay results to gel-based oligonucleotide ligation assay (OLA) results showed 99.3% agreement in genotype assignments. Substitution of direct-labeled R6G dideoxynucleotide with indirect-labeled phycoerythrin dideoxynucleotide enhanced signal five- to tenfold while maintaining low noise levels. A new assay based on allele-specific primer extension (ASPE) was validated on a set of 15 multiplexed SNPs for 96 patients. ASPE offers both the advantage of streamlining the SNP analysis protocol and the ability to perform multiplex SNP analysis on any mixture of allelic variants.

Flow Cytometry↗

PubMed2001

Elevated interleukin-13 in patients with active lupus nephritis.

OBJECTIVE: To investigate the significance of interleukin-13 (IL-13) in patients with active lupus nephritis (LN). METHODS: Ten healthy volunteers and 16 patients with active LN were included in this study. The protein level of IL-13 in plasma was examined by enzyme linked immunosorbent assay (ELISA), and gene expression of IL-13 in peripheral blood mononuclear cells (PBMCs) by reverse transcription polymerase chain reaction (RT-PCR). Expression of IL-13 mRNA in renal tissue was studied by in situ hybridization (ISH) techniques. RESULTS: The level of IL-13 in plasma and the expression of IL-13 mRNA in PBMCs were significantly higher in LN patients than those in the controls (P < 0.001). Increased expression of IL-13 mRNA was detected in renal tissue of active LN patients compared to those in the controls (P < 0.001). Analysis of the linear correlation indicated that the level of IL-13 mRNA in the tubulointerstitial area in patients with active LN correlated with the concentration of serum creatinine (Scr), the glomerular activity index (GAI), the activity index of tubulointerstitium, and the level of serum C3 (P < 0.05 for each). CONCLUSION: The elevation of IL-13 may play an important role in the molecular pathogenesis of active LN.

Adult↗

PubMed2001

[Geographic distribution and feature of Yersinia pestis plasmid isolated from Yunnan province].

OBJECTIVE: To analysis the molecular-epidemiological feature of Yersinia pestis plasmid isolated from Yunnan. METHODS: One thousand and twenty strains of Y. pestis isolates from 44 counties of Yunnan province in China and the border of China-Myanmar using Kado and Liu method and detected by agrose gel electrophoresis. RESULTS: Results showed that these strains from Yunnan province carried 9 kinds of plasmids with molecular weights about 3.93, 6.05, 22.97, 35.65, 45.35, 64.82, 74.59, 111.36 and 129.55 x 10(6). Of these, three kinds of 3.93, 35.65 and 111.36 x 10(6) were found very specific, only reported in Yunnan. The plasmid profile could be divided into 10 types according to the plasmid content. Type I-V were common and had a clustering nature in geographic distribution. CONCLUSION: Based on the plasmid profile, the epidemic districts of plague could be divided into several independent plague foci, suggesting that the resurgence of domestic rat caused plague epidemics might have several hidden plague foci as the result of epidemics since 1982 in Yunnan.

Animals↗

PubMed2001

[Determination of triacontanol and octacosanol in fenglasu and fenglasu capsules by capillary gas chromatography].

OBJECTIVE: The method was established for the determination of triacontanol and octacosanol in fenglasu and fenglasu capsules. METHODS: The solvent was chloroform. The internal standard was hexatriacontanol. Using SIMPLCITY-1 capillary column, flame ionization detector was specified, injector temperature was 300 degrees C, and the column temperature rise by programming. [Initial temperature was 240 degrees C, maintaining 1 min and then rising the temperature (5 degrees C.min-1) to 300 degrees C for 15 min]. The flow rate of Nitrogen was 27 ml.min-1. RESULTS: The calibration curves were linear in the range of 0.4-1.6 mg/ml for triacontanol(r = 0.999), 0.2-0.6 mg/ml for octacosanol(r = 0.9996) respectively. The average recovery (n = 9) was 99.2% for triacontanol (RSD = 1.15%), 99.91% for octacosanol (RSD = 1.40%). CONCLUSION: The method is rapid, accurate and reliable for the quality control of fenglasu and fenglasu capsules.

Capsules↗

PubMed2001

[Technique and advance of comprehensive two-dimensional gas chromatography].

Many analytical problems require more resolution than the conventional single column chromatographic technique can provide. In such cases the separation power can be enhanced by using more than one separation technique or mechanism. The sample is then dispersed in different time dimensions. The resolution obtained depends strongly on the difference between these dimensions. The highest resolution is gained when there is no correlation between the separations, the dimensions being orthogonal to each other. Comprehensive two-dimensional gas chromatography (GC x GC) provides a true orthogonal separation system in which a modulator serially couples two columns containing dissimilar stationary phases. It focuses and subsequently reinjects components eluting from the first column into the second one. The system generates a peak capacity that is approximately equal to the product of the peak capacities of the two individual separation systems. In this paper, technique and instrumental considerations of GC x GC are discussed. The three designs of contemporary GC x GC systems are presented and compared. A number of typical applications on complex samples such as petroleum products and environmental pollutants are also cited. Finally, the future perspectives of GC x GC are simply discussed.

Chromatography, Gas↗

PubMed2001

[The clinic treatment of traumatic optic neuropathy].

OBJECTIVE: To observe the visual outcome of traumatic optic neuropathy treated with optic canal decompression surgery and medication. METHOD: 15 patients, suffering from traumatic optic neuropathy, had received medication and optic canal decompression surgery through the approach of ethmoid and sphenoid sinus. The vision acuity was divided into 5 grades: no light perception, light perception, finger movement, counting fingers, vision > or = 0.1, the vision acuity improvements reaching 2 grades or more were determined as effective. All patients were followed up for intervals of 1 month and 6 months. RESULT: The total efficient rate is 57.4%, no intraoperative or postoperative complications were encountered. Being followed up 6 months, 2 cases, who underwent respectively the operation 8, 11 days after trauma, felt no light perception. CONCLUSION: The approach through ethmoid and sphenoid sinus have the merits such as safety, less damage and larger operative field. Timely medication, megacorticosteroid therapy mainly, may play a good role in alleviating optic nerve edema and restoring its function. Comprehensive therapy may be an ideal treatment to traumatic optic neuropathy.

Adolescent↗

PubMed2001

[Detection of telomerase activity in laryngeal carcinoma and the association between telomerase activity and lymphatic metastasis].

OBJECTIVE: To investigate the telomerase activity in human laryngeal squamous cell carcinomas (LSCC) and the association between telomerase activity and lymphatic metastasis. METHOD: Telomerase activity was determined in 47 specimens of LSCC and 10 specimens of laryngeal inflammatory polyps using PCR-ELISA. RESULT: Telomerase activity was detected in 39 of 47 (83%) LSCC, but was not detected in all 10 laryngeal inflammatory polyps. There were significant differences between them (P < 0.01). Telomerase activation in LSCC with positive cervical lymph node involvement appeared to be higher (13 out of 13 cases, 100%) than in LSCC with negative cervical lymph node involvement (26 out of 34, 76.47%), (P < 0.05). CONCLUSION: Telomerase is activated frequently in LSCC and may become a biomarker of LSCC. The detection of telomerase activity in LSCC may have some value for predicting metastasis potential and prognosis and can guide the clinical practices applying selective neck dissection.

Adult↗

PubMed2001

[Genetic instability in cancer tissues analyzed by RAPD PCR].

In five kinds of tumors, total 128 specimens were analyzed by RAPD (random amplified polymorphic DNA) PCR with nine 10-base arbitrary primers for detecting instabilities of DNA and chromosome and screening new molecular markers coupled to putative or unknown oncogenes and/or tumor suppressor genes. Bands representing instabilities have been recovered and purified from agarose and cloned into pCAPs vector, and further labeled by DIG as probes for analysis of Southern blot, Northern blot and Sequencing. Results revealed that sample 5 and 3 of the gastric cancers showed the highest genomic changes and the average detectability in five sorts of cancers was up to at least 40% (42.2%-49.4%), and that there were significant differences in the ability of each primer to detect genomic instability, which ranged from 27% to 68%. Despite the highest detectability of genetic instability (68%) in tumor tissues, primer 2 could produce stable profiles of DNA bands in normal tissue genome with good reproducibility. On the contrary, primer 8 was of the lowest one (27%). Band B of single copy found to be allelic losses in gastric and colon cancers according to RFLP analysis was of a novel sequence and registered by Gen-Bank (Accession Number AF151005). Therefore the genetic instabilities often concentrated on some special locuses of chromosome e.g. repetitive sequences etc. and coupled to carcinogenesis. It was impossible or difficult to get great achievements for cancer treatments with the procedure of gene therapy only to one oncogene or one tumor suppressor gene because the extensive DNA variations occurred during the progression of tumor. RAPD assay connected with other techniques was a good tool for the detection of genomic instabilities and direct screening of some new molecular markers related to tumor suppressor genes or oncogenes.

Base Sequence↗

PubMed2001

[Pharyngeal passage tube treatment for obstructive apnea syndrome].

OBJECTIVE: To investigate the therapeutical effect of pharyngeal passage tube for OSAS. METHODS: Fifty-seven patients were treated during May 1995 to August 1999. All patients were examined by GKD-405 A polysomnography for apnea index (AI), hypnea index (HI), AHI (AI + HI) at cetera 7 items index before and after pharyngeal passage tube treatment. RESULTS: After treatment, the longest time of apnea shortened from (54.82 +/- 20.83) s to (25.74 +/- 9.50) s, the AHI lessened from 70.82 +/- 18.06 to 30.00 +/- 10.10, the oxygen desaturation increased from (62.36 +/- 11.53)% to (78.68 +/- 12.09)%. After treatment, the recorded parameters showed obvious therapeutical effect (P < 0.05-0.001, t values is from 2.20 to 15.29, the snore loudness of all patients dropped from (84.32 +/- 18.51) dB to (32.64 +/- 10.16) dB. The therapeutical successful rate was 87.72%. The long-term use rate (over 6 months) was 72.73%. CONCLUSION: The pharyngeal passage tube has obvious effect for patients suffering from severe OSAS. It is recommended for the treatment of OSAS as a conservative method.

Adult↗

PubMed2001

[Surgery of the skull base assisted by sinus endoscope].

OBJECTIVE: To explore the feasibility and clinical value of the endoscopic operations around the skull base. METHODS: A retrospective study was made of 44 cases treated by endoscopic operations. Twenty-five cases underwent intranasal endoscopic operations. RESULTS: Forty of 44 cases were cured by one-stage surgery. One case of cartridge foreign body clamped in clivus was not successfully removed; only window operation and puncture biopsy were done in another case of pituitary adenoma; high cranial pressure has not been completely reduced after operation in the third case with relapsing craniopharyngioma a companied with obstructive hydrocephalus. One case of sphenoidal malignant adenoma involving saddle based and extended laterally was partly resected. Complications were follows: cerebrospinal fluid rhinorrhea in 2 cases, diabetes insipidus in 1 case, all of them were cured by conservative treatment; nasal septum perforation in 1 case, without any treatment. CONCLUSIONS: The endoscopic skull base surgery by intranasal approach is feasibility. Intranasal approach has direct path, slight wound and no wound in face. Combined with operation microscope, sinus endoscope can make up for its limits.

Endoscopy↗

PubMed2000

Inhibitors of src tyrosine kinase: the preparation and structure-activity relationship of 4-anilino-3-cyanoquinolines and 4-anilinoquinazolines.

Src is a nonreceptor tyrosine kinase involved in signaling pathways that control proliferation, migration, and angiogenesis. Increased Src expression and activity are associated with an increase in tumor malignancy and poor prognosis. Several quinolines and quinazolines were identified as potent and selective inhibitors of Src kinase activity.

Enzyme Inhibitors↗

PubMed2000

Inhibition of cardiac tumor necrosis factor-alpha production by calcitonin gene-related peptide-mediated ischemic preconditioning in isolated rat hearts.

Previous investigations have demonstrated that calcitonin gene-related peptide (CGRP) plays an important role in the mediation of ischemic preconditioning in rats. In the present study, we examined signal transduction pathways of CGRP-mediated ischemic preconditioning. Thirty minutes of global ischemia and 40 min of reperfusion caused a dramatic decrease in myocardial function, and a significant increase in the release of cardiac creatine kinase in the coronary effluent and in the content of tumor necrosis factor-alpha (TNF-alpha) in myocardial tissues. However, ischemic preconditioning (three cycles of 5-min ischemia and 5-min reperfusion) or pretreatment with CGRP for 5 min dramatically improved the recovery of cardiac function, and reduced the release of cardiac creatine kinase and the TNF-alpha content. The effect of ischemic preconditioning was abolished by CGRP-(8-37), the selective CGRP receptor antagonist, and by capsaicin, which depletes sensory nerve neurotransmitter content, but was unaltered by treatment with glibenclamide, a blocker of the ATP-sensitive potassium (K(ATP)) channel. The protective effects of exogenous CGRP-induced preconditioning were also not blocked by glibenclamide. These results suggest that the cardioprotective effects afforded by CGRP-mediated ischemic preconditioning are related to inhibition of cardiac TNF-alpha production, but not to activation of the K(ATP) channel.

Animals↗

PubMed2000

Light-induced down-regulation of the rat class 1 dynein-associated protein robl/LC7-like gene in visual cortex.

Dynein and kinesin are the main microtubule-dependent motors that mediate intracellular movement in eukaryotic organisms. We have cloned a full-length cDNA encoding rat dynein light chain protein, robl/LC7-like (class 1), from visual cortex. We found that rat robl/LC7-like gene is highly expressed in neocortex and displays the unusual feature of being rapidly down-regulated by sensory stimulation. This effect was seen at both mRNA and protein levels in visual cortex, being detectable in as little as 45 min after the onset of visual stimulation. Down-regulation by sensory stimulation was also found within ocular dominance columns of area V1 in monocularly deprived monkeys. Our results suggest a high turnover rate of the robl/LC7-like protein and the presence of a repressor mechanism in neurons that is tightly coupled to synaptic stimulation.

Amino Acid Sequence↗

PubMed2000

4-Anilino-6,7-dialkoxyquinoline-3-carbonitrile inhibitors of epidermal growth factor receptor kinase and their bioisosteric relationship to the 4-anilino-6,7-dialkoxyquinazoline inhibitors.

The synthesis and SAR of a series of 4-anilino-6, 7-dialkoxyquinoline-3-carbonitrile inhibitors of epidermal growth factor receptor (EGF-R) kinase are described. Condensation of 3, 4-dialkoxyanilines with ethyl (ethoxymethylene)cyanoacetate followed by thermal cyclization gave, regiospecifically, 6,7-dialkoxy-4-oxo-1, 4-dihydroquinoline-3-carbonitriles. Chlorination (POCl(3)) followed by the reaction with substituted anilines furnished the 4-anilino-6, 7-dialkoxyquinoline-3-carbonitrile inhibitors of EGF-R kinase. An alternate synthesis of these compounds starts with a methyl 3, 4-dialkoxybenzoate. Nitration followed by reduction (Fe, NH(4)Cl, MeOH-H(2)O) gave a methyl 2-amino-4,5-dialkoxybenzoate. Amidine formation using DMF-acetal followed by cyclization using LiCH(2)CN furnished a 6,7-dialkoxy-4-oxo-1,4-dihydroquinoline-3-carbonitrile, which was transformed as before. Compounds containing acid, ester, amide, carbinol, and aldehyde groups at the 3-position of the quinoline ring were also prepared for comparison, as were several 1-anilino-6,7-dimethoxyisoquinoline-4-carbonitriles. The compounds were evaluated for their ability to inhibit the autophosphorylation of the catalytic domain of EGF-R. The SAR of these inhibitors with respect to the nature of the 6,7-alkoxy groups, the aniline substituents, and the substituent at the 3-position was studied. The compounds were further evaluated for their ability to inhibit the growth of cell lines that overexpress EGF-R or HER-2. It was found that 4-anilinoquinoline-3-carbonitriles are effective inhibitors of EGF-R kinase with activity comparable to the 4-anilinoquinazoline-based inhibitors. A new homology model of EGF-R kinase was constructed based on the X-ray structures of Hck and FGF receptor-1 kinase. The model suggests that with the quinazoline-based inhibitors, the N3 atom is hydrogen-bonded to a water molecule which, in turn, interacts with Thr 830. It is proposed that the quinoline-3-carbonitriles bind in a similar manner where the water molecule is displaced by the cyano group which interacts with the same Thr residue.

Aniline Compounds↗

PubMed2000

Over expression of integrin alpha 5 beta 1 in human hepatocellular carcinoma cell line suppresses cell proliferation in vitro and tumorigenicity in nude mice.

Integrin alpha 5 beta 1 and alpha 2 beta 1 are the major integrin receptors in human hepatocytes. However, in human hepatocellular carcinoma cells it was found that the expression of integrin alpha 5 beta 1 was decreased and another integrin alpha 6 beta 1 increased. In this study, the SMMC7721 human hepatocellular carcinoma cells cotransfected or singly transfected with integrin alpha 5 and/or beta 1 cDNAs were established, and designated alpha 5 beta 1.6-7721, alpha 5.3-7721, and beta 1.6-7721 cell lines, respectively. Transfection with cDNAs of integrin alpha 5 and beta 1 subunits resulted in the over expression of each integrin and modified biological properties, including a slowed growth rate, changes in the cell cycle from 15.5% of control cells in the G2/M phase to 12.1%, 9.6% and 9.4% in alpha 5.3-7721, beta 1.6-7721, alpha 5 beta 1.6-7721, respectively, and a decrease in the Cell Mitosis Index from 1.6 in controls to 0.96, 0.95, and 0.72, and 34%, 28% and 52% derived from colony forming ability, respectively. Tumorigenicity was also tested in nude mice with inoculation of cells subcutaneously. Tumor masses growing in nude mice following inoculation with beta 1.6-7721, and alpha 5 beta 1.6-7721 cells weighed only 52% or 31% those of control cells. These results indicated that deletion or low expression of integrin alpha 5 beta 1 may play an important role in the development of hepatocellular carcinoma. Therefore, induction of expression of the integrin alpha 5 beta 1 in malignant cells could be a potential means of treating hepatocellular carcinoma.

Animals↗

PubMed2000

A protein kinase C-independent pathway leading to c-Jun-dependent expression of 100-kDa Ras GTPase-activating protein in JEG-3 human choriocarcinoma cells.

Although the 100-kDa Ras GTPase-activating protein (p100 RasGAP) has been reported to exist specifically in human placental trophoblasts, the molecular mechanisms responsible for regulating its expression remain unclear. In this study we used okadaic acid, an inhibitor of serine/threonine phosphatase 1 and 2 A, as a probe to explore the signaling pathway regulating the expression of p100 RasGAP in JEG-3 human placental choriocarcinoma cells. Treatment of JEG-3 cells with okadaic acid provoked dose- and time-dependent stimulation of p100 RasGAP expression without marked modification of expression of p120 RasGAP, another isoform of RasGAP. Co-treatment of cells with okadaic acid and the protein kinase C activator, phorbol 12-myristate 13-acetate, exerted an additive effect on p100 RasGAP induction. Moreover, the response of the p100 RasGAP de novo synthesis to okadaic acid was not affected by the selective inhibitor of protein kinase C, GF 109203X. Thus this study identified a novel signaling pathway regulating p100 RasGAP expression, which is independent of protein kinase C. In addition, okadaic acid treatment resulted in the activation of ERK2 (p42 MAP kinase) and the induction of both c-Jun and c-Fos proteins without activating JNK (c-Jun NH2-terminal kinase). Significantly, blockade of c-Jun expression with antisense c-jun oligonucleotides suppressed p100 RasGAP expression. Taken together, it is concluded that okadaic acid induces the expression of p100 RasGAP protein in JEG-3 cells preceded by activation of ERK and AP-1 cascade, and that this okadaic acid-induced p100 RasGAP expression is independent of protein kinase C-mediated pathway but requires c-Jun/AP-1 function.

Cell Differentiation↗

PubMed2000

Molecular maps of neural activity and quiescence.

The rapid accumulation of inducible transcription factors (ITFs), such as c-Fos and Zif268, in activated neurons combined with histological methods that offer detection at the cellular level are key features that have led to their wide use in visualizing activated neurons. There are two major drawbacks of ITFs that limit their use in the CNS--cell-type expression specificity and stimulus-transcription coupling uncertainty. Recent technical advances in the field of molecular activity mapping now permit dual-labeling approaches that help resolve some of these ambiguities and identify neurons that are activated by different sensory stimuli. Furthermore, the recent identification of the robl/LC7-like gene, which shows immediate-early repression after stimulation, may have utility in functional mapping where it can be used to delineate quiescent neurons and serve as a complement to molecular activity markers.

Animals↗

PubMed2000

[Identification of a new molecular marker related to tumorigenesis of the stomach and small intestine].

OBJECTIVE: Screening and identification of molecular markers associated with tumorigenesis of the gastrointestinal tract. METHODS: Techniques of random amplified polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP), Southern blot and Northern blot, gene cloning and sequencing were employed to reveal new molecular markers from tumors of different origins. RESULTS: Of 32 RAPD fragments possibly associated with tumorigenesis, 29 were cloned into pCAPs vector. Further analysis by Southern blot revealed that the majority of the cloned fragments was repetitive sequences. Among the remaining single-copy fragments, one was found deleted in malignant tumors of the stomach and small intestine. It did not hybridize with mRNA extracted from blood lymphocyte and cultured fibroblasts. Sequence analysis indicated that this single-copy fragment contained a motif similar to eukaryotic cis-acting "CACA" box promoter. At its downstream there was an "ATG" transcription activator codon. No homologous sequence was found in the GenBank and it was therefore accepted by the GenBank. (Accession Number: AF151005). CONCLUSION: A single-copy fragment containing cis-acting "CACA" box has been identified, which might be the upstream of a new tumor suppressor gene deleted in tumors of the stomach and small intestine.

Biomarkers, Tumor↗