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Biomedical subjects

Sheng Wang

Publications and source records attributed to Sheng Wang.

At least 55 records · Page 3Linked to original sources
PubMed2004

BRG1/BRM and prohibitin are required for growth suppression by estrogen antagonists.

Estrogen antagonists are universally employed in the breast cancer therapy, although antagonist therapy is limited by the inevitable development of cellular resistance. The molecular mechanisms by which these agents inhibit cellular proliferation in breast cancer cells are not fully defined. Recent studies have shown the involvement of the E2F pathway in tamoxifen-induced growth arrest. We show that an E2F repressor, prohibitin, and the chromatin modifiers Brg1/Brm are required for estrogen antagonist-mediated growth suppression through the estrogen receptor, and that their recruitment to native promoter-bound E2F is induced via a JNK1 pathway. In addition, we demonstrate major mechanistic differences among the signaling pathways initiated by estrogen, estrogen deprivation, and estrogen antagonists. Collectively, these findings suggest that the prohibitin/Brg1/Brm node is a major cellular target for estrogen antagonists, and thereby also implicate prohibitin/Brg1/Brm as potentially important targets for breast cancer therapy.

Anthracenes↗
PubMed2004

Selective vasodilator and chronotropic actions of 3',4'-dihydroxyflavonol in conscious sheep.

Flavonoids are known to relax isolated large arteries, but the cardiovascular actions of flavonoids are not well studied in vivo. Hence, we determined the systemic and regional haemodynamic responses to a novel synthetic flavonol, 3',4'-dihydroxyflavonol (DiOHF), in conscious sheep previously instrumented with flow probes on the aorta and coronary, mesenteric, renal, and iliac arteries. Intravenous injection of DiOHF (1.0 mg/kg) caused a delayed but prolonged vasodilatation in the coronary and renal vascular beds, with no changes in the mesenteric or iliac vascular beds. DiOHF induced prolonged increases in heart rate and cardiac output without altering arterial pressure. Pretreatment with Nomega-nitro-L-arginine, a nonspecific inhibitor of nitric oxide synthase, abolished all the cardiovascular effects of DiOHF. The results indicate that DiOHF caused a nitric oxide-dependent vasodilatation of the coronary and renal vasculature and an increase in cardiac output due to its chronotropic action.

Acetaminophen↗
PubMed2004

Capsaicin facilitates carotid sinus baroreflex in anesthetized rats.

The effects of capsaicin (CAP) on the carotid sinus baroreflex were studied in 30 anaesthetized rats with perfused isolated carotid sinus. The results are as follows. (1) By perfusing the isolated carotid sinus with CAP (1 micromol/L), the functional curve of the baroreflex was shifted to the left and downward, with a peak slope (PS) increasing from 0.34+/-0.01 to 0.42+/-0.01 (P<0.01), whereas the reflex decrease (RD) in mean arterial pressure was enhanced from 36.51+/-1.26 to 45.01+/-0.71 mmHg (P<0.01). Meanwhile, the threshold pressure, equilibrium pressure and saturation pressure were all significantly decreased from 70.43 +/-2.09 to 52.86 +/-2.80 mmHg (P<0.01), 95.5+/-1.71 to 87.00+/-1.58 mmHg (P<0.01) and 177.60+/-1.37 to 163.55+/-2.12 mmHg (P<0.01), respectively. Among the functional parameters of carotid baroreflex, the changes in PS and RD induced by capsaicin were dose-dependent. (2) By pretreatment with ruthenium red (RR, 100 micromol/L), an antagonist of vanilloid receptor subtype 1 (VR(1)), the above effects of CAP on carotid baroreflex were abolished. (3) The CAP-induced change in the baroreflex was also eliminated by pretreatment with glibenclamide (20 microm ol/L), a K(ATP) channel blocker. On the basis of the results, it is concluded that CAP facilitates the carotid baroreflex, an effect of which may be resulted from the opening of K(ATP) channels mediated by VR(1).

Animals↗
PubMed2004

Analysis of chromosome abnormalities by comparative genomic hybridization in malignant peripheral primitive neuroectodermal tumor of the ovary.

OBJECTIVE: Malignant primitive neuroectodermal tumor (PNET) originating from the ovary rather than from the central nervous system is extremely rare. The aim of this study is to demonstrate the chromosomal abnormalities in a case of peripheral primitive neuroectodermal tumor (PPNET) arising from the ovary of a girl. METHODS: The 13-year-old girl underwent exploratory laparotomy because of a huge pelvic tumor in lower abdomen and pelvis. She underwent removal of ovaries, tubes, omentum, peritoneal nodules, and portion of urinary bladder. Tumor specimens were sent for pathology, short-term tissue culture, and for storage in deep freezer for laboratory studies. Immunohistochemical stainings of the tumor with antibodies against O-13 (MIC/CD99), NSE, GFAP, S-100, cytokeratin AE1/AE3, desmin, NF, and AFP were performed. Short-term cell culture of fresh tumor was done for analysis of chromosomal aberrations by the technique of comparative genomic hybridization (CGH). Names of specific genes corresponding to the losses or gains on gene map loci were identified from OMIM (Online Mendelian Inheritance in Man) of the NCBI website,. The overexpressions of N-myc and EGFR as well as underexpressions of Rb and ARHI were detected by RT-PCR analysis. The patient expired 17 months later despite of chemotherapy, repeated surgery, and radiation therapy. RESULT: The histopathology of the specimens revealed malignant neuroectodermal tumor, involving ovaries, tubes, bladder, omentum, and peritoneum. Immunohistochemical stainings of PPNET of the ovary showed positive reaction for O-13 (MIC2/CD99) and NSE, but negative for GFAP, S-100, cytokeratin AE1/AE3, desmin, NF, and AFP. Analysis of CGH revealed multiple chromosomal abnormalities including losses of chromosomes in 1p, 1q, 4q, 6p, 6q, 7q, 8q, 13q, and 19q; as well as gains of chromosomes in 1q, 2p, 7p, 9q, 18q, and Xq. Losses of 13q14.1-q14.2, 1p31, and 4q34-q35 indicated that Rb gene, ARHI, and FAT were deleted. Gains of 2p24.1, 1q23, and 7p12.3-p12.1 demonstrated that N-myc oncogene, FASL, GITRL, and EGFR were amplified. RT-PCR analysis showed that N-myc and EGFR were overexpressed, while Rb and ARHI were underexpressed. CONCLUSIONS: This report is the first to show multiple chromosomal aberrations in PPENT arising from the ovary. The deletions of Rb, ARHI, and FAT, as well as amplification of N-myc, FASL, GITRL, and EGFR, may be the crucial factors for tumorigenesis and the aggressive biological behavior of PPNET.

Adolescent↗
PubMed2004

Molecular characterization of a new lectin from the marine alga Ulva pertusa.

A new lectin, named UPL1, was purified from a green alga Ulva pertusa by an affinity chromatography on the bovine-thyroglobulin-Sepharose 4B column. The molecular mass of the algal lectin was about 23 kD by SDS-PAGE, and it specifically agglutinated rabbit erythrocytes. The hemagglutinating activity for rabbit erythrocytes could be inhibited by bovine thyroglobulin and N-acetyl-D-glucosamine. The lectin UPL1 required divalent cations for maintenance of its biological activity, and was heat-stable, and had higher activity within pH 6-8. The N-terminal amino acid sequence of the purified lectin was determined (P83209) and a set of degenerate primers were designed. The full-length cDNA of the lectin was cloned by rapid amplification of cDNA ends (RACE) method (AY433960). Sequence analysis of upl1 indicated it was 1084 bp long, and encoded a premature protein of 203 amino acids. The N-terminal sequence of the mature UPL1 polypeptide started at amino acid 54 of the deduced sequence from the cDNA, indicating 53 amino acids lost due to posttranslational modification. The primary structure of the Ulva pertusa lectin did not show amino acid sequence similarity with known plant and animal lectins. Hence, this protein may be the paradigm of a novel lectin family.

Acetylglucosamine↗
PubMed2004

Disruption of the Rb--Raf-1 interaction inhibits tumor growth and angiogenesis.

The retinoblastoma tumor suppressor protein (Rb) plays a vital role in regulating mammalian cell cycle progression and inactivation of Rb is necessary for entry into S phase. Rb is inactivated by phosphorylation upon growth factor stimulation of quiescent cells, facilitating the transition from G(1) phase to S phase. Although the signaling events after growth factor stimulation have been well characterized, it is not yet clear how these signals contact the cell cycle machinery. We had found previously that growth factor stimulation of quiescent cells lead to the direct binding of Raf-1 kinase to Rb, leading to its inactivation. Here we show that the Rb-Raf-1 interaction occurs prior to the activation of cyclin and/or cyclin-dependent kinases and facilitates normal cell cycle progression. Raf-1-mediated inactivation of Rb is independent of the mitogen-activated protein kinase cascade, as well as cyclin-dependent kinases. Binding of Raf-1 seemed to correlate with the dissociation of the chromatin remodeling protein Brg1 from Rb. Disruption of the Rb-Raf-1 interaction by a nine-amino-acid peptide inhibits Rb phosphorylation, cell proliferation, and vascular endothelial growth factor-mediated capillary tubule formation. Delivery of this peptide by a carrier molecule led to a 79% reduction in tumor volume and a 57% reduction in microvessel formation in nude mice. It appears that Raf-1 links mitogenic signaling to Rb and that disruption of this interaction could aid in controlling proliferative disorders.

Animals↗
PubMed2004

[Analysis on the occurrence of violence among the injury surveillance program in the Emergency Department].

OBJECTIVE: To explore the characteristics of violence events occurred at the Emergency Department in the hospital and to provide evidence for prevention and control of the problem. METHODS: Surveillance on injuries was performed on those patients who first visited the Emergency Department in a general hospital in Shantou from January 1st 2000 to December 31th 2002. RESULTS: A total number of 11 472 injured patients registered in a 3-year surveillance program at the Emergency Department. Among the patients under surveillance, 29.0% of them were injured by violence events. The ratio of male to female was 3.8:1. The high risk age groups of violence patients were 15 - 44 years (77.1%) with workers as the majority. Home was the most common place for suicide/self-hurt (occupied 42.2%), and highway seemed to be the most common place for homicide/be injured (occupied 44.7%) to occur. Pre-hospital care for the injured patients was mostly taken care by other people (80.1%). Opening trauma appeared to be the most common injury caused by the violence. CONCLUSION: Our study on violence surveillance program at the Emergency Department provided information for identifying the main problems and population at high risk. Violence surveillance in the emergency department of different areas needs to be carried out in order to take preventive measures accordingly.

Age Factors↗
PubMed2004

[Inhibitory effects of basic fibroblast growth factor on fibrosis of strain injured skeletal muscles in rats].

OBJECTIVE: To investigate the effects of exogenous basic fibroblast growth factor (bFGF) on the healing of strain injured skeletal muscles in rats. METHODS: Eighteen male SD rats were randomly divided into three groups: no strain control group (C(on)), muscle strained and bFGF treated group (S(b)), or normal saline treated group (S(0)). The gastrocnemius of rats in the S(b) and S(0) groups was strained and the animals were treated with bFGF (200 AU/d) or normal saline for six days. Vimentin expression, an indicator of muscle fibrosis in injured muscles (expressed as integral optical density, IOD), was measured by immunohistochemistry. RESULTS: The IOD of vimentin in the S(0) group [(24.29 +/- 7.91) x 10(3)] was higher than that in the C(on) group [(5.75 +/- 3.87) x 10(3)] (P < 0.01). The IOD of vimentin in bFGF treated group [(15.78 +/- 7.72) x 10(3)] was lower than that in the normal saline treated group (P < 0.01). CONCLUSION: The exogenous bFGF may facilitate the repair of muscle structure and function by reducing vimentin expression and fibrosis in strain injured muscles.

Animals↗
PubMed2004

[Effect of lumbar protective belt on prevention of low back fatigue in personnel during simulated driving].

OBJECTIVE: To observe low back fatigue of subjects before and after simulated driving, and to study the role of the belt used in prevention of low back fatigue of drivers during driving. METHODS: To assess the changes in median frequency (MF), mean power frequency (MPF) of surface electromyogram (SEMG), and flicker frequency, visuognosis persistence of drivers with and without protective belt in simulated driving. RESULTS: There were significant differences in MF [(47.35 +/- 6.07), (39.26 +/- 5.79), (47.21 +/- 6.02), (43.44 +/- 6.26) Hz respectively], MPF [(69.86 +/- 7.08), (59.12 +/- 7.19), (69.86 +/- 7.08), (63.88 +/- 7.49) Hz respectively] between before and after simulated driving without or with the special belt (P < 0.01). But no differences in MF or MPF between without and with the belt before simulated driving were found (P > 0.05). The flicker frequency [(35.64 +/- 2.82), (42.31 +/- 4.68), (35.96 +/- 3.05), (39.79 +/- 3.36) Hz], visuognosis persistence (65.77% +/- 3.94%, 56.83% +/- 5.68%, 65.88% +/- 3.92%, 62.27% +/- 2.91%) had some changes too. CONCLUSION: Simulated diving could induce fatigue of back muscle in drivers. However, the protective belt can effectively prevent low back fatigue of drivers in simulated driving.

Adult↗
PubMed2004

[Dendritic cells, natural killer cells and adhesion molecules in psoriasis].

OBJECTIVE: To study the role of the dendritic cells, natural killer cells and adhesion molecules play in the pathogenesis of psoriasis. METHODS: The expression levels of human leukocyte antigen (HLA)-DR, CD1a, CD16, CD57, tumor necrosis factor (TNF)-alpha and intercellular adhesion molecule (ICAM)-1 were detected by immunohistochemistry in lesions of 26 patients with psoriasis before and after treatment. RESULTS: The expression of HLA-DR, CD1a, CD16, CD57, TNF-alpha and ICAM-1 showed no significant difference between the active phase and the static phase of psoriatic lesions (P>0.05). After treatment, the positive expression of all markers decreased evidently or even disappeared with histopathological improvement in the resolvent phase of psoriatic lesions. There were statistically significant difference by Wilcoxon rank sum test (P<0.05). CONCLUSION: Dendritic cells, natural killer cells and adhesion molecules play an important role in the pathogenesis of psoriasis.

Adult↗
PubMed2004

[Anti-arrhythmic effect of starfish sterol].

AIM: To study the effect of modified starfish sterol [C03, succinic acid (5-epiandroene-17-one-3beta-ol) diester] on experimental arrhythmias. METHODS: Arrhythmias were induced by drugs (Aco, Oua, BaCl2 and adrenalin) i.v., ligating the left anterior descending coronary artery and electricity. RESULTS: C03 71.4 mg x kg(-1) (ig) was shown to increase the dose of Oua inducing VP, VT, VF and CA in guinea pigs (P < 0.01); C03 (26.8, 80.4 mg x kg(-1)) was found to increase the dose of Aco inducing VF and CA in rats (P < 0.01); C03 (8.9, 26.8, 80.4 mg x kg(-1)) increase the dose of barium chloride and delay the onset time of ventricular arrhythmias (P < 0.01); C03 (14.1, 42.3 mg x kg(-10) shorten time of recovering induced by adrenalin in rabbits (P < 0.01); C03 (80.4 mg x kg(-1)) was shown to reduce the number of ventricular arrhythmias induced by coronary artery ligation in rats (P < 0.05), C03 increase VFT induced by electricity in rabbits, VFT of C03 14.1 mg x kg(-1) increased from (5.1 +/- 2.5) V to (11.0 +/- 2.7) V (P < 0.01), 42.3 mg x kg(-1) increased from (6.1 +/- 1.7) V to (15 +/- 5) V (P < 0.01). CONCLUSION: Starfish sterol has anti-arrhythmic effect.

Aconitine↗
PubMed2004

[Quality evaluation of prepared slices of Paeonia lactiflon--determination of paeoniflorin by HPLC].

OBJECTIVE: To establish the quality criteria of the prepared slices of Paeonia lactiflon. METHOD: RP-HPLC was used for the determination of paeoniflorin in 10 lots of samples by ultrasound-assisted extraction. RESULT: The samples were extracted with 50% methanol. Seperation of the solution was performed on an ODS column with a mobile phase of acetonitrile-water (18:82), detected at 230 nm. CONCLUSION: The method is simple, repeatable, accurate and applicable.

Benzoates↗
PubMed2004

[Pretreatment and resource utilization of industrial effluent with benzoic acid].

Extraction equilibrium of benzoic acid were studied using 20%, 30% and 50% tributyl phosphate (TBP) in kerosene, 1-octanol and toluene as the extractants, to investigate the efficient method of recovering benzoic and acetic acid in the industrial effluent and meeting the requirement of the terminal wastewater treatment. The CODCr value in residual phase and the recovery of benzoic acid in various extractants were measured. The results showed that the recovery of benzoic acid was closed to 100% with 50% TBP/kerosene system, and depended on the polarity of extractant for pure solvent system. The recovery with 1-octanol was equivalent to the one with 30% TBP. The CODCr value in the residual phase depended on the CODCr value from benzoic acid and the solubility of extractant, which does not depend on the benzoic acid concentration in the residue phase apparently, and shown 50% TBP approximately equal to 30% TBP > 1-octanol > 20% TBP > toluene. Meanwhile, the profitable diagram of pretreatment of industrial effluent with benzoic acid was suggested, i.e. firstly, extract benzoic acid with toluene and return the toluene to the benzoic acid reactor, then, extract acetic acid with trialkylphosphine oxide and back-extract the acetic acid with CaO or MgO to produce calcium magnesium acetate.

1-Octanol↗
PubMed2004

Effects of estrogen on gastrocnemius muscle strain injury and regeneration in female rats.

AIM: To study the effects of estrogen on muscle damage and regeneration after acute passive gastrocnemius muscle strain injury in female Sprague-Dawley rats. METHODS: Rats were divided into 5 groups: ovariectomized, strained and treated with low-dosage estradiol (20 microg/d) (E(low)), treated with high-dosage estradiol (200 microg/d) (E(high)), treated with oil placebo (Oil), strained with no ovariectomy (Strain), and sham operated with no strain and no ovariectomy (Con). Muscle damage index [plasma creatine kinase (CK)], antioxidant indexes [glutathione (GSH), Vitamin E (Vit E), total antioxidant capability (TAC)], and muscle regeneration index (desmin) were investigated at 7 d. RESULTS: The plasma CK activity increased but GSH, Vit E, and TAC levels decreased after muscle strain injury (Strain vs Con P<0.05). Plasma CK activity was the greatest while GSH, Vit E, and TAC were the lowest in the Oil group among the five groups (P<0.01). Plasma CK in the E(high) and Strain groups was lower than that in the E(low) group. Plasma GSH, Vit E, and TAC were higher in the E(high) and Strain groups compared with the E(low) group (P<0.05). The expression of desmin in the E(high) and Strain groups was higher than that in the E(low) group (P<0.01) while that in the Oil group was the lowest in all the five groups (P<0.01). CONCLUSION: Endogenous estrogen in normal female rats or exogenous estrogen in ovariectomized rats could improve antioxidant capability in vivo, so that reduced muscle damage and accelerated muscle regeneration post gastronemius muscle strain injury.

Animals↗
PubMed2004

Trends in injury-related incidence and mortality among inpatients in Guangdong Province in 1997-2001.

OBJECTIVE: Currently, China is in short of thorough and systemic data concerning the patterns and incidence of injuries and related deaths. Guangdong Province as one of the economically advanced areas in China is faced with a relatively serious injury problem, and investigation of this problem in this Province will provide valuable information for other provinces and areas in this Country, as well as scientific basis for policy making for injury prevention and control. METHODS: Analyses are based on the computerized hospital discharge data collected from 322 hospitals in Guangdong Province between 1997 and 2001. Diagnoses are coded according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM). RESULTS: The total hospitalization rate related with injuries increased year by year from 1997 to 2001. The ratio of case-fatality has a decline trend for all injury inpatients, who were mainly caused by motor vehicle accidents, unintentional falls, puncture and cut by machine and others. The constituent ratio of death among patients caused by motor vehicle accidents accounted for 56.13% among the total deaths, which ranked as the first place. The direct medical cost also had an increased trend. CONCLUSIONS: Data on injuries requiring hospitalization can be used to design and target more effective injury prevention programs. Injury prevention would decrease human sufferings, disability, and associated economic losses.

Accidents, Traffic↗