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W Su

Publications and source records attributed to W Su.

At least 37 records · Page 2Linked to original sources
PubMed2001

Portal vein thrombosis following laparoscopic splenectomy for beta-thalassemia: a case study.

Portal vein thrombosis is a rare but well-recognized complication of splenectomy. We present the case of a 31-year-old woman with transfusion-dependent b-thalassemia who underwent a laparoscopic splenectomy to reduce her transfusion requirements. Postoperatively, she developed portal vein thrombosis, diagnosed by abdominal CT scanning on postoperative day 4. After being treated with anticoagulation and antibiotic therapy, she obtained prompt resolution of her symptoms. This report summarizes the first reported incidence of portal vein thrombosis following laparoscopic splenectomy and presents the current theories regarding the etiology and treatment of postsplenectomy portal vein thrombosis.

Adult↗
PubMed2001

Nordihydroguaiaretic acid elevates osteoblastic intracellular Ca2+.

Nordihydroguaiaretic acid (NDGA) is widely used as a pharmacological tool to inhibit lipoxygenases; however, recent evidence suggests that it increases renal intracellular [Ca2+]i via novel mechanisms. Here the effect of NDGA on Ca2+ signaling in MG63 osteoblastic cells was explored using fura-2 as a Ca2+ indicator. NDGA (2-50 microM) increased [Ca2+]i in a concentration-dependent manner. The signal comprised an initial rise and an elevated phase over a time period of 4 min. Removing extracellular Ca2+ reduced 2-50 microM NDGA-induced signals by 62+/-2%. After incubation with 50 microM NDGA in Ca2+-free medium for several minutes, addition of 3 mM CaCl2 induced an increase in [Ca2+]i. NDGA (50 microM)-induced [Ca2+]i increases were not changed by pretreatment with 10 microM of verapamil, diltiazem, nifedipine, nimodipine and nicardipine. In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin (1 microM) inhibited 50 microM NDGA-induced [Ca2+]i increases by 69+/-3%. Inhibition of phospholipase C with 2 microM U73122 had little effect on 50 microM NDGA-induced Ca2+ release. Several other lipoxygenase inhibitors had no effect on basal [Ca2+]i. At a concentration that did not increase basal [Ca2+]i, NDGA (1 microM) did not alter 10 microM ATP- or 1 microM thapsigargin-induced [Ca2+]i increases. Alteration of protein kinase C activity with 1 nM phorbol 12-myristate 13-acetate or 2 microM GF 109203X did not affect 50 microM NDGA-induced [Ca2+]i increases. Together, the results show that NDGA increased [Ca2+]i in osteoblasts in a lipoxygenase-independent manner, by releasing stored Ca2+ in a fashion independent of phospholipase C activity, and by causing Ca2+ influx.

Calcium↗
PubMed2001

Transport of opioids from the brain to the periphery by P-glycoprotein: peripheral actions of central drugs.

Many peptides and transmitters found within the brain also have peripheral sites of action. We now demonstrate that the brain releases functionally active neurotransmitters/neuromodulators directly from the brain into the blood through a saturable P-glycoprotein (Pgp) transport system. Downregulating Pgp1 expression with antisense reduced the brain-to-blood transport of morphine, beta-endorphin and other opioids. Lowering Pgp expression significantly enhanced systemic morphine analgesia and prevented tolerance, but diminished the analgesic activity of centrally administered morphine, implying that supraspinal analgesia resulted from a combination of central and peripheral mechanisms activated by morphine transported from the brain to the blood. Similarly, mice with a disruption of the Mdr1a gene were more sensitive to systemic morphine and less sensitive to morphine given centrally. This ability of the Pgp transport system to pump functionally active compounds from the brain to periphery defines a potentially important mechanism for the central nervous system to modulate peripheral systems.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed2001

Fendiline mobilizes intracellular Ca2+ in Chang liver cells.

1. The effects of the antianginal drug fendiline (N-[3,3-diphenylpropyl]-alpha-methyl-benzylamine) on intracellular free Ca2+ levels ([Ca2+](i)) in Chang liver cells were evaluated using fura-2 as a fluorescent Ca2+ indicator. 2. Fendiline (1-100 micromol/L) increased [Ca2+](i) in a concentration-dependent manner, with an EC50 of 25 micromol/L. 3. The [Ca2+](i) response was composed of an initial rise and a slow decay to a sustained phase. Removal of extracellular Ca2+ partly reduced the [Ca2+](i) signals. 4. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was reduced by 65% following pretreatment with 1 micromol/L thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete Ca2+ stored in the endoplasmic reticulum. 5. After pretreatment with 10 micromol/L fendiline in Ca2+-free medium for several minutes, addition of 3 mmol/L Ca2+ induced an increase in [Ca2+](i) of a magnitude four-fold greater than control. This increase in [Ca2+](i) was not reduced by 10 micromol/L SKF96365, econazole, nifedipine or verapamil. 6. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was not altered by inhibition of phospholipase C with 2 micromol/L 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino) hexyl)-1H-pyrrole-2,5-dione (U73122). 7. The results of the present study show that fendiline induces an increase in [Ca2+](i) in Chang liver cells by releasing stored Ca2+ in an inositol 1,4,5-trisphosphate-independent manner and by causing extracellular Ca2+ influx.

Calcium↗
PubMed2001

Antitumor and antifungal activities in endophytic fungi isolated from pharmaceutical plants Taxus mairei, Cephalataxus fortunei and Torreya grandis.

The purpose of this work was to screen the endophytic fungi having antitumor or antifungal activity, which were isolated from the inner barks of three kinds of pharmaceutical plants, Taxus mairei, Cephalataxus fortunei and Torreya grandis, collected from Fujian province, China. Antitumor activity was studied by the MTT assay and antifungal activity was determined by observing fungal growth inhibition. 13.4% of endophytic fungi fermentation broths displayed cytotoxic activity on HL-60 cells at and below a dilution of 1:50, and 6.4% on KB cells. 52.3% of endophytic fungi fermentation broths displayed growth inhibition on at least one pathogenic fungi, such as Neurospora sp., Trichoderma sp. and Fusarium sp. Among all endophytic fungi isolated, the genus Paecilomyces sp. has the highest positive rate of antitumor and antifungal activity. These results indicate that endophytic fungi could be a promising source for antitumor and antifungal bioactive agents.

Antifungal Agents↗
PubMed2001

Mechanism of bradykinin-induced Ca(2+) mobilization in MG63 human osteosarcoma cells.

BACKGROUND: The effect of bradykinin on intracellular free Ca(2+) levels ([Ca(2+)](i)) in MG63 human osteosarcoma cells was explored using fura-2 as a Ca(2+) dye. METHODS/RESULTS: Bradykinin (0.1 nM-1 microM) increased [Ca(2+)](i) in a concentration-dependent manner with an EC(50) value of 0.5 nM. The [Ca(2+)](i) signal comprised an initial peak and a fast decay which returned to baseline in 2 min. Extracellular Ca(2+) removal inhibited the peak [Ca(2+)](i )signals by 35 +/- 3%. Bradykinin (1 nM) failed to increase [Ca(2+)](i) in the absence of extracellular Ca(2+ )after cells were pretreated with thapsigargin (an endoplasmic reticulum Ca(2+) pump inhibitor; 1 microM). Bradykinin (1 nM)-induced intracellular Ca(2+) release was nearly abolished by inhibiting phospholipase C with 2 microM 1-(6-((17 beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). The [Ca(2+)](i )increase induced by 1 nM bradykinin in Ca(2+)- free medium was abolished by 1 nM HOE 140 (a B2 bradykinin receptor antagonist) but was not altered by 100 nM Des-Arg-HOE 140 (a B1 bradykinin receptor antagonist). Pretreatment with 1 pM pertussis toxin for 5 h in Ca(2+) medium inhibited 30 +/- 3% of 1 nM bradykinin-induced peak [Ca(2+)](i) increase. CONCLUSIONS: Together, this study shows that bradykinin induced [Ca(2+)](i) increases in a concentration-dependent manner, by stimulating B2 bradykinin receptors leading to mobilization of Ca(2+) from the thapsigargin-sensitive stores in a manner dependent on inositol-1,4,5-trisphosphate, and also by inducing extracellular Ca(2+) influx. The bradykinin response was partly coupled to a pertussis toxin-sensitive G protein pathway.

Biological Transport↗
PubMed2001

[Photocatalytic degradation of bromomethane on sol-gel-derived SO4(2-)/TiO2].

SO4(2-)/TiO2 photocatalysts were prepared by sol-gel method and characterized by X-ray diffraction (XRD), FTIR spectroscopy and N2 sorption analysis applying BET method. Photocatalytic decomposition of CH3Br in air stream was studied over SO4(2-)/TiO2 photocatalysts under the different reaction conditions. The results showed that the addition of SO4(2-) to TiO2 greatly enhanced its structural and photocatalytic properties. The optimum concentration of SO4(2-) on TiO2 was 9% wt and the best calcination temperature was 450 degrees C. Moreover, the sulfated TiO2(SO4(2-)/TiO2) exhibited excellent stability of activity under the moist reaction condition. When the reaction temperature was below 85 degrees C, the reactivity of bromomethane was enhanced with increasing reaction temperatures, and the apparent Arrehenius activation energy was 19.6 kJ.mol-1. In the reaction temperature range of 85 degrees C-105 degrees C, the apparent Arrehenius activation energy was zero.

Catalysis↗
PubMed2001

Automatic analysis of image of surface structure of cell wall-deficient EVC.

Some computer applications for cell characterization in medicine and biology, such as analysis of surface structure of cell wall-deficient EVC (El Tor Vibrio of Cholera), operate with cell samples taken from very small areas of interest. In order to perform texture characterization in such an application, only a few texture operators can be employed: the operators should be insensitive to noise and image distortion and be reliable in order to estimate texture quality from images. Therefore, we introduce wavelet theory and mathematical morphology to analyse the cellular surface micro-area image obtained by SEM (Scanning Electron Microscope). In order to describe the quality of surface structure of cell wall-deficient EVC, we propose a fully automatic computerized method. The image analysis process is carried out in two steps. In the first, we decompose the given image by dyadic wavelet transform and form an image approximation with higher resolution, by doing so, we perform edge detection of given images efficiently. In the second, we introduce many operations of mathematical morphology to obtain morphological quantitative parameters of surface structure of cell wall-deficient EVC. The obtained results prove that the method can eliminate noise, detect the edge and extract the feature parameters validly. In this work, we have built automatic analytic software named "EVC.CELL".

Cell Membrane↗
PubMed2001

Growth inhibition of gastric cancer cells by all-trans retinoic acid through arresting cell cycle progression.

OBJECTIVE: To investigate the mechanism of all-trans retinoic acid (ATRA) on the regulation of the cell cycle in gastric cancer cells. METHODS: The protein level was detected by Western blot. Immunoprecipitation was used in protein kinase activity determination. Cell growth and cell cycle phase were examined by MTT assay and flow-cytometric analysis, respectively. RESULTS: ATRA could effectively induce G0/G1 arrest and inhibit cell growth in certain human gastric cancer cell lines. ATRA might induce p21WAF1/CIP1 expression in ATRA-sensitive cell lines through p53-dependent and p53-independent pathways. Induction of p21WAF1/CIP1 caused decrease in CDK4 and CDK2 activities independent of CDK4 and CDK2 protein expression levels. In addition, the dephosphorylated form of Rb protein increased because of the down-regulation of CDK4 and CDK2 activities by ATRA. CONCLUSIONS: Growth inhibition on gastric cancer cells by ATRA occurs through the regulation of relevant proteins leading to the arrest of cell cycle progression.

Antineoplastic Agents↗
PubMed2001

[The identification of flos magnoliae by TLC].

OBJECTIVE: To establish a TLC identification method for Flos Magnoliae. METHOD: Selecting optimum TLC conditions. RESULTS: A TLC identification method of Flos Magnoliae has been established. CONCLUSION: The method is simple, accurate and reliable.

Chromatography, Thin Layer↗
PubMed2001

[Study of bacteriology on local application of Tinidazole stilus in treatment for periodontitis].

OBJECTIVE: The study was designed to evaluate the antiseptic efficacy of Tinidazole stilus against periodontal pathogen. METHODS: A total of 41 patients with periodontitis were included in this study. 26 of them were treated by Tindazole stilus and other 15 cases were treated by metronidazole stilus as controls. The prevalence of subgingival bacteria from both group were examined. RESULTS: The eliminate rates for Black pigmented anaerobic rod (Porphyromonas gingivalis, Prevotella intermedius, Prevotella melaninogenicus), Fusobacteriums, Prevotella oris, Prevotella oralis, Eubacterium and Actinomyces were 95.8% 94.1%, 83.3% and 76.5%. The anti-bacterial efficiency of Tinidazole against periodontal pathogen was significantly higher than that of metronidazole (P < 0.05). CONCLUSION: It appears to be effective to use Tinidazole stilus as local application against periodontal pathogens.

Administration, Topical↗
PubMed2001

[Application of fingerprint analysis and computer pattern interpretation in identification and quality evaluation of traditional Chinese medicines].

The fingerprint analysis technique used in the quality control of TCM through identifying charactreristics and evaluating stability is set up with the rapid development of instrument analyses and computer pattern interpretation. There are many kinds of methods for establishment of fingerpirnt of TCM mainly including chromatography, spectroscopic method, x-ray diffraction and molecular biological technique. The methods of computer pattern interpretation in fingerprint of TCM includes fuzzy information analysis, artificial neural networks and gray relational grade cluster.

China↗
PubMed2001

[The factors that influence the consistency of international normalized ratio of prothrombin time].

OBJECTIVE: To investigate the factors that influence the consistency of international normalized ratio (INR) of prothrombin time. METHODS: Using the same automated blood coagulation analyzer and INR calibration plasma with two different types of prothrombin time (PT) reagent to assay the INR values of 19 controls (group 1), 12 patients who took long-term anticoagulant orally (group 2), 12 patients who took it at the first time (group 3) and 8 patients who took long-term anticoagulant together with cephalosporin N (group 4). RESULTS: The two kinds of reagents gave quite different INR values in all four groups (P < 0.01). The INR difference in group 3 (0.23 +/- 0.07, n = 12) was larger than that in group 2 (0.51 +/- 0.20, n = 12) (P < 0.01). The difference in group 4 (0.61 +/- 0.21, n = 8) was larger than that in group 2 (P < 0.01). CONCLUSIONS: The factors that may influence INR consistency are the source and sensitivity of the reagents, as well as the period of the anti coagulant been taken and the other drugs taken at the same time.

Administration, Oral↗
PubMed2001

[Spectrum studies on titania photocatalysts].

The nano-sized TiO2 photocatalysts were prepared by sol-gel method and characterized by FTIR spectroscopy, FT-Raman spectroscopy and diffuse reflectance spectroscopy(DRS). Photocatalytic degradation of oleic acid over the TiO2 catalysts was investigated. The result showed that calcination temperature has strong effect on crystal structure, energy band structure, optical adsorption and photocatalytic activity of the TiO2 catalysts. It was found that the TiO2 photocatalyst calcined at 400 degrees C has the best apparent optical adsorption, the biggest band edge position and the highest photoactivity. The effect of calcination temperature on photocatalytic activity of TiO2 catalysts has been ascribed to the changes in structure and optical property of catalyst such as crystal size, content of rutile, residual NO3-, and band-edge position of light adsorption.

Adsorption↗
PubMed2000

Taxol from Tubercularia sp. strain TF5, an endophytic fungus of Taxus mairei.

The diterpenoid taxol is an important anticancer agent used widely in the clinic. The purpose of this work was to identify a taxol-producing endophytic fungus (strain TF5) isolated from Taxus mairei and study its anticancer activities. Strain TF5 was identified as a Tubercularia sp. according to the morphology of the fungal culture, the mechanism of spore production and the characteristics of the spores. Strain TF5 produced taxol, when grown in potato dextrose liquid medium and analyzed by thin layer chromatography, high performance liquid chromatography, ultraviolet and mass spectrometry. The fungal taxol, which was isolated from the organic extract of the TF5 culture, had strong cytotoxic activity towards KB and P388 cancer cells in vitro, tested by the MTT assay. Observed with immunofluorescence and electron microscopy, the fungal taxol enhanced microtubule stability and bundling in culture cells and induced tubulin polymerization in vitro similar to the authentic taxol.

Animals↗