Biomedical subjects

Li Wang

Publications and source records attributed to Li Wang.

At least 271 records · Page 15Linked to original sources

PubMed2005

Effect of vinblastine on transfection: influence of cell types, cationic lipids and promoters.

As previously shown, vinblastine, when incorporated into a cationic lipid prior to generation of lipoplexes, increases by approximately 30-fold the extent of transfection of pbeta-Gal with a cytomegalovirus promoter (pCMV-beta-Gal) to vascular smooth muscle cells (VSMC) by 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EDOPC)-pCMV-beta-Gal complexes. To test if this increase is limited to VSMC and EDOPC, or is general, we examined three other cell types, human umbilical artery endothelial cells (HUAEC), baby hamster kidney (BHK) cells and 293 cells derived from human kidney, as well as a different cationic lipid, 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP). In addition, to determine the contribution of the NF-kappaB transcription factor to the vinblastine effect, pCMV was replaced with a smooth muscle gamma-actin gene promoter, SMGA, which, unlike pCMV, does not respond to NF-kappaB. It was found that on all cell types we tested, the transfection efficiency increased with vinblastine incorporation; however, the magnitude depended greatly on the cell type, e.g. whereas the transfection of VSMC increased approximately 30-fold, that of 293 cells increased only approximately 2-fold. The cationic phospholipid could be replaced with DOTAP with no loss of effect. In contrast, the promoter was critical and the stimulation was lost if pCMV was replaced with pSMGA. It is concluded that the positive effect of vinblastine on transfection is general and the stimulation of the transcription factor NF-kappaB is involved in this action. The activation of NF-kappaB by anti-microtubule agents should thus allow for transfection of specific cell types by vinblastine lipoplexes.

Actins↗

PubMed2005

[Cloning and subcellular localization of apr-1--a new gene of tumor specific antigen family].

BACKGROUND & OBJECTIVE: apr-1 was cloned by improved polymerase chain reaction (PCR)-based subtractive hybridization from all-trans retinoic acid (ATRA)-induced apoptotic leukemia HL-60 cells in 1999. Preliminary results showed that apr-1 might be an apoptosis-related gene (GenBank ID: NM_014061). This study was to explore the background of apr-1 through gene cloning, bioinformatic analysis, and subcellular locating. METHODS: The cDNA encoding Apr-1 was amplified by reverse transcription-PCR (RT-PCR), and sequenced. Open reading frame (ORF) of apr-1 was analyzed with ORF finder software. Chromosome locus was defined by genome blast software. Conserved domains of amino acids were analyzed by protein blast software. Align (Cluster W) software in Vector NTI software package was used to analyze homogeneous genes (or proteins), and to draw the Phylogenetic Tree. Subcellular localization of apr-1 was performed. RESULTS: apr-1 was mapped to chromosome Xp11.22 with the ORF locating in 1 exon. Two MAGE conserved domains were found in Apr-1. Apr-1 shared homology with MAGE-A1, MAGE-B1, MAGE-C1, MAGE-D1, and Necdin. Phylogenetic analysis showed that Apr-1 was more closely related to MAGE-D1 and Necdin. Gene products of apr-1 were located in the nuclei of eukaryocytes. CONCLUSIONS: apr-1 is a member of MAGE family, and might belong to type II MAGE genes.

Amino Acid Sequence↗

PubMed2005

[Recognition and study of susceptible gene to ankylosing spondylitis].

To study the potential correlations between variances of TNFalpha gene and onset of ankylosing spondylitis in Chinese population, We scanned and analyzed the promoters of TNFalpha genes in 75 AS patients from south of China and found -850 T mutation allele frequency rather high (39.3%).By case-control study, the distribution of TT genotype is significantly higher in AS patients than that in normal subjects (10.7% VS 2.1%,P=0.003); Mutation T allele has a remarkable difference between AS group and normal control (72.2% vs 21.4%,P=2.729 x 10(-9)). The difference in distribution of TX genotype and non -TX genotype is also significant statistically between different genders(male: P=3.42 x 10(-9);female: P=0.001). The result suggests that this variation has a strong association with AS in males and females. No similar reports about the association between AS and the T mutation allele have been acquired. Therefore, our hypothesis can be supported by our results on the whole and the -850 C-->T mutation allele in the region on promoter of TNFalpha gene is likely one of susceptible genes to AS.

Adolescent↗

PubMed2005

Overexpression of osteopontin in rheumatoid synovial mononuclear cells is associated with joint inflammation, not with genetic polymorphism.

OBJECTIVE: Osteopontin (OPN) is thought to play an important role in rheumatoid synovitis. We investigated the expression of OPN in rheumatoid synovial fluid mononuclear cells (SFMC) and its potential association with genetic polymorphism of the OPN gene and joint inflammation in rheumatoid arthritis (RA). METHODS: 1. The expression of OPN mRNA in peripheral blood mononuclear cells (PBMC) and SFMC of patients with RA was analyzed quantitatively by real-time polymerase chain reaction (PCR). Results were analyzed in paired PBMC and SFMC and control PBMC. 2. Six single nuclear acid polymorphisms of the OPN gene were genotyped in a cohort of 192 Chinese patients with RA and controls (n = 288) by restriction fragment length polymorphism PCR or direct DNA sequencing. 3. SF derived from RA patients was examined for the stimulating effect on mRNA expression of the OPN gene in PBMC. RESULTS: The expression of OPN gene was significantly increased in SFMC and, to a lesser degree, in PBMC of patients with RA compared to control PBMC (p < 0.01). However, the prevalence of OPN genotype and allele frequencies at the selected positions did not differ significantly between RA patients and the control group (p > 0.05). Further characterization indicated that SF known to contain a variety of proinflammatory factors significantly stimulated mRNA expression of OPN in PBMC obtained from RA patients or healthy controls. CONCLUSION: Overexpression of OPN mRNA in SFMC is associated with proinflammatory factors produced in inflamed joints, but not with OPN genetic polymorphisms. OPN gene polymorphisms do not correlate with susceptibility to RA.

Adult↗

PubMed2005

[Clinicopathological and immunohistochemical study of oral teratoid cyst].

OBJECTIVE: To investigate clinicopathological and immunohistochemical features of 31 cases of oral teratoid cyst. METHODS: Thirty-one cases of oral teratoid cyst according with Meyer's diagnosis criteria were retrospectively studied and their histochemistry and immunohistochemistry were performed from the files of Department of Pathology, School of Stomatology, Wuhan University between 1963 and 2003. RESULTS: Twenty-seven cases (87.10%) were children, and twenty-four cases were congenital. The ratio of male-to-female was 1:0.55, and the affected sites were floor of mouth (22 cases) and tongue (8 cases). Clinical findings were nonspecific, and prognosis was good following complete excision. Histology indicated that squamous, respiratory and/or gastrointestinal epithelium consistiuted basic structure of teratoid cyst in addition to simple cuboidal epithelium in 8 cases. Antibody against AE1/AE3 was strongly expressed and CK16 was weak in four types of epithelial lining of oral teratoid cyst. Expression of AE1, CK7, 8/18, 19 varied in superficial, suprabasal and basal cells of squamous epithelium but were strong in respiratory, gastrointestinal and simple columnar epithelium; only gastrointestinal epithelium expressed CK20 heterogeneously. CONCLUSIONS: Oral teratoid cyst showed the highest incidence in children, and floor of mouth and tongue were mostly affected sites. Features of histology were complex, and immunohistochemistry indicated that epithelium of oral teratoid cyst shared similar patterns of cytokeratin with counterpart of normal tissues, showing different origin and differentiation of epithelial lining of the present cyst.

Adolescent↗

PubMed2005

[The preparation of the polylacticacid nanoparticles of cucurbitacin and their drug loading].

This paper introduced an experimental study of the preparation of polylacticacid (PLA) nanoparticles of cucurbitacin (CuC) using a precipitation method. The residual acetone, ratio of CuC PLA precipitates, and the relationships between the ratios of two precipitates and drug incorporation rates were measured. It appeared that the nanoparticles with 60% of PLA incorporated with 5.5% of CuC were formed when acetone was injected into the aqueous phase. As the acetone gradually evaporated, drug incorporation/encapsulation continued, with most of CuC (about 70%) formed new crystalline cores and suspended in the form of microcrystals in the medium, resulting a suspension containing both nanoparticles and microcrystals. We also concluded that this system may not necessarily be suitable for all lipophilic drugs to be prepared to PLA nanoparticles with good incorporation rate. The drug incorporation depended on the interactions among drug, PLA, and organic solvents, in addition to the solubility of the drug.

Antineoplastic Agents, Phytogenic↗

PubMed2005

Overexpression of chloroplast-localized small molecular heat-shock protein enhances chilling tolerance in tomato plant.

There are many reports about the correlation between small molecular heat-shock protein (sHSP) and the acquirement of chilling tolerance, but no direct evidence that sHSP confers enhanced chilling tolerance to plant has been reported. A DNA construct, including tomato chloroplast-localized small molecular heat-shock protein (CPsHSP) cDNA under the control of cauliflower mosaic virus 35S (35SCaMV) promoter, was introduced into the genome of tomato plants. The chilling tolerance of the transgenic tomato lines and the non-transgenic tomato was evaluated. After exposure to chilling stress, the transgenic plants exhibited lighter chilling-injured symptoms, suffered less electrolyte leakage and less destruction of chlorophyll, accumulated less anthocyanins and less MDA and kept higher value of net photosynthetic rate, than non-transgenic plant. All results indicated consistently that transgenic tomato plants had stronger chilling tolerance. These characters are ascribed to constitutive expression of cpshsp and lead to the conclusion that HSP can enhance chilling tolerance in plant.

Acclimatization↗

PubMed2005

[Progress in the molecular mechanisms of nuclear coactivator PGC-1].

Peroxisome proliferators-activated receptor-gamma coactivator-1 is broadly involved in several key cellular pathways including mitochondrial biogenesis, hepatic gluconeogenesis via interacting with many transcription factors, which is highly valuable to maintain the energy balance of organisms. This review especially focuses on the recent progress in the molecular docking, histone acetylation, RNA processing basing on the structure of PGC-1 gene and amino acid sequence. Besides, the prospect of PGC-1 in applications of metabolic syndromes has been discussed also.

Acetylation↗

PubMed2005

[Anatomic study on the recurrent laryngeal nerve in thyroid surgery].

OBJECTIVE: To study the anatomic characteristic and dissecting approach of recurrent laryngeal nerve in thyroid surgery. METHOD: A retrospective review of surgical data of consecutive 56 patients undertook thyroid surgery was conducted, in which total 63 recurrent laryngeal nerves were identified. RESULT: A nerve bifurcation was found in 48 recurrent laryngeal nerves. Twenty-nine nerves were deep to the inferior thyroid artery, 19 were superficial to the artery, 8 were between the arteries. The inferior thyroid artery was not found in 7 cases. CONCLUSION: Correct identification and safe dissection of the recurrent laryngeal nerve are essential in thyroid surgery.

Adult↗

PubMed2005

[Photovoltaic character of organic EL devices MEH-PPV/Alq3].

An organic photovoltaic(PV) cell, ITO/MEH-PPV/Alq3/LiF/Al, was fabricated. The MEH-PPV and Alq3 are the electron-acceptor and donor in the cell, respectively. The respond region matchs the adsorption of Alq3 film. Under UV light with 0.5 mW x cm(-2), the cell shows a short-circuit current of 2.4 microA x cm(-2), open-circuit voltage of 2.6 V, a fill factor of 0.71, and a power conversion efficiency of 0.9%. It was found that the PV cell indicates electroluminescence (EL) performance and could emit orange light at DC voltage. The maximum luminance is about 1 000 cd x cm(-2) at 15 V.

Aluminum↗

PubMed2005

[Advanced oxidation protein products-induced tumor necrosis factor alpha secretion in monocytes via reactive oxygen species generation].

OBJECTIVE: To investigate the effect of advanced oxidation protein products (AOPP) on the secretion of tumor necrosis factor alpha eTNFalphae in monocytes and its possible mechanism. METHOD: Human monocyte cell line THP-1 and peripheral blood monocytes were incubated with AOPP-bovine serum albumin(BSA) prepared by incubation of BSA with hypochlorous acid. TNFalpha in the supernatant of the culture medium of THP-1 cells was measured by enzyme-linked immunosorbent assay and the production of reactive oxygen species (ROS) evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2,7-dichlorefluorescin using Wallac 1420 multilabel counter. The intracellular signal was observed by pre-treatment of the cells with antioxidant pyrrolidine dithiocarbamate, NADPH oxidase inhibitor apocynin or p38 phosphorylation inhibitor SB203580. RESULTS: AOPP-BSA induced TNF-alpha secretion and ROS production in monocytes. Pretreatment of the cells with pyrrolidine dithiocarbamate scavenged most of ROS and almost completely blocked TNF-alpha secretion induced by AOPP-BSA. Inhibition of NADPH oxidase by apocynin and p38 phosphorylation by SB203580 could both effectively block AOPP-BSA-induced TNF-alpha secretion. CONCLUSION: AOPP-BSA induced TNF-alpha secretion in monocytes, and the intracellular signaling involves ROS produced by activated NADPH oxidase and subsequent p38 phosphorylation.

Blood Proteins↗

PubMed2005

[Loss of heterozygosity induced by cyclophosphamide at tk locus in human lymphoblastoid cell line TK6].

OBJECTIVE: Human lymphoblastoid cell line TK6 was used to investigate TK gene mutation frequency and the loss of heterozygosity (LOH) induced by cyclophosphamide (CP). METHODS: Relative survival, mutation frequency at tk locus induced by CP (+S9) after 4 h treatment were detected. DNA isolated from mutants in the control culture and CP treatment group was analyzed for LOH. RESULTS: Exposure to CP for 4 h decreased relative survival, induced TK gene mutation in a dose-dependent manner. Doubling time of normally and slowly growing mutants was (14.6 +/- 1.74) h and (35.8 +/- 3.78) h respectively. The percentage of hemizygous LOH in CP-induced mutants (50%) was 2.4 times than that of the control (20.7%). CONCLUSION: Great damage to TK gene is the main cause of mutation induced by CPin TK6 cells.

Cell Line↗

PubMed2005

[Natural history of small hepatocellular carcinoma: studied by MRI].

OBJECTIVE: To study natural history of small hepatocellular carcinoma (sHCC) and value of MRI in this research. METHODS: From 1999 to 2002, serial MR imagings were performed in 192 patients with cirrhosis no less than twice in order to detect sHCC focus. Characteristic MRI findings of focus were analysed. Diameters of focus (D) were measured. Tumorigenesis detected time (T) was counted; T and D were analysed by statistics and tumor volume doubling time (T(d)) was calculated. RESULTS: Fifty-eight new tumor foci in 33 patients were found, including 31 foci in 23 patients developed on the basis of cirrhosis, with a 12.0% cumulative tumorigenic rate of three years. The tumorigenesis detected time (T) was 386.9 +/- 256.4 days and the maximum diameter (D) was 2.258 +/- 1.074 cm. T was statistical correlated with D(3) (P < 0.01) and regressive formulas were established: D(3) = -2.69 + 0.058T (P = 0.0007), D(3) = -72.13 + 16.04lnT (P = 0.0064). Tumor volume doubling time was 20 approximately 279 days (mean: 104 days). CONCLUSION: The percentage of tumorigenesis is high in patients with cirrhosis. Regular MRI examinations are necessary to detect sHCC early. The optimal interval time is 3 approximately 6 months.

Adult↗

PubMed2005

[Effects of uvulopalatopharyngoplasty surgery on subsequent continuous positive airway pressure in patients with obstructive sleep apnea-hypopnea syndrome].

OBJECTIVE: To determine the effect of uvulopalatopharyngoplasty (UPPP) therapy on post-surgery continuous positive airway pressure (CPAP) treatment during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS), and to evaluate the use of Bi-level positive airway pressure (BiPAP) in whom CPAP therapy failed. METHODS: Thirty-four OSAHS patients after UPPP surgery were tested more than 3 months after the procedure. Among them 25 patients were treated with classical UPPP (cUPPP), in which all of the uvula and part of the soft palate were removed. Nine underwent modified UPPP (mUPPP), keeping part of the uvula. The control group consisted of 34 age, body mass index (BMI) and apnea hypopnea index (AHI) matched, newly diagnosed OSAHS patients without prior treatment. Four patients receiving both pre- and post-surgery tests were included in both groups. A manual titration of CPAP to determine the optimal CPAP pressure (oCPAP) and the highest CPAP pressure (hCPAP) the patient can tolerate was performed during both NREM and REM sleep in all 68 patients. RESULTS: 72% of the UPPP patients had less than 50% decrease in AHI, and 82% of the 34 patients still had AHI > 15 during post-operation PSG test. Hence, most of them needed further therapy. All of the untreated OSAHS patients could tolerate 17-20 cm H2O of CPAP during NREM and REM sleep. None had severe mouth air leak before an oCPAP was reached. In contrast, five in the surgery group failed to respond to CPAP treatment during both NREM and REM sleep, and one more during REM sleep. All of the nine patients who had a mUPPP could tolerate CPAP. One of the four tested both before and after surgery failed to respond to CPAP treatment after surgery during REM sleep and one during both NREM and REM sleep. However, the six patients failed to respond to CPAP treatment tolerated BiPAP therapy well. CONCLUSIONS: In a considerable number of patients with OSAHS, UPPP may compromise the applicability of nasal CPAP as a subsequent therapy, and BiPAP might be a treatment option for patients who could not tolerate CPAP treatment.

Adult↗

PubMed2005

[Studies on the optimized extraction technology of Paeonia suffruticosa].

OBJECTIVE: To obtain the optimized extraction technology of Paeonia suffruticosa by comparing several extraction method. METHOD: Extract P. suffruticosa by ethanol circumfluence, distillation-decoction, CO2-SFE and traditional decoction, and analyse the results according to the total extraction rate, extraction rate of paeono, extraction of other ingredients and production feasibility. RESULT: Total extraction rates of which are 12.66%, 13.51%, 7.28%, 7.56% respectively; extraction rates of paeonol are 2.45%, 2.26%, 0.31%, 1.15% in turn; Phenolic glycosides can be extracted by ethanol circumfluence, distillation-decoction, traditional decoction, but not by CO2-SFE. CONCLUSION: Distillation-decoction is the most proper extraction technology of P. suffuticosa at present.

Acetophenones↗

PubMed2005

[Beneficial neurohormonal profiles of beta-blockades in chronic left heart failure].

OBJECTIVES: The aims of this study were to evaluate the effects of beta-blockers on neurohormonal factors in patients with chronic left heart failure (CHF). METHODS: 44 patients, 33 men and 11 women, with age of 60.1 +/- 10.6 years with chronic left heart failure (ejection fraction less or equal to 40% by UCG) were included in this study. All patients received conventional therapy and were randomly assigned either to a bisoprolol or carvedilol group. The dosage of beta-blockers were increased gradually to target or the tolerant dosages (bisoprolol 10 mg qd, carvedilol 25 mg bid) during 3 months in 36 patients. Maintenance dose was continued for 4 months. Plasma concentrations of renin activity (PRA), angiotensin II (Ang II), aldosterone (Ald) and the N-terminal portion of brain natriuretic (NT-proBNP) were assessed with RIA and ELISA at baseline and 3 and 7 months after staring beta-blocker therapy. Left ventricular ejection fraction (LVEF, Modify SIMPSON) was assessed at baseline and 7 months after starting therapy. RESULTS: (1) In patients with left heart failure, the baseline plasma level of PRA, Ang II and Ald were at normal range. N-terminal BNP concentration was much higher than 200 pg/ml as a result of impaired systolic function, as it elevated with increasing of NYHA grade. (2) The plasma level of NT-proBNP decreased significantly, as compared with that before therapy, but there is no significant change of plasma level of PRA, Ang II and Ald. (3) There were no significant differences between the event group and non-event group for the plasma level of renin-angiotensin and aldosterone during 7 months after starting beta-blocker. The Plasma levels of NT-proBNP were much higher in the event group than non-event group. (4) Multi regression analysis showed that the value of LVEF increased with the decreasing of NT-proBNP levels (beta = -0.389, P = 0.009) and increasing of Ang II level (beta = 0.341, P = 0.020) at baseline. After-therapy LVEF increased with the decreasing of NT-proBNP levels at titration-end (beta = -0.424, P = 0.020). CONCLUSIONS: The plasma level of NT-proBNP is more sensitive and accurate than the plasma level of PRA, Ang II and Ald in evaluation of severity and prognosis of CHF. beta-Blocker administration in patients with CHF decreases circulating levels of NT-proBNP and thus improves left ventricular function, but there is no significant effect on plasma level of PRA, Ang II and Ald.

Adolescent↗

PubMed2005

[The changing pancreatic cancer mortality in China (1991-2000)].

OBJECTIVE: To describe the mortality rate of pancreatic cancer and its distribution in China during the period of 1991-2000. METHODS: Based on the data of demography and death collected through China's Disease Surveillance Point System (DSPS) over the period of 1991-2000, the distribution of death rate of pancreatic cancer was described in terms age group, gender, calendar year, rural/urban residence and administrative district. RESULTS: A total of 1619 mortal cases attributed to pancreatic cancer (975 men and 644 women) were reported by DSPS from 1991 to 2000. The reported, adjusted and age-standardized mortality rates increased from 1.46, 1.75, and 2.18 per 100,000 populations in 1991 to 2.38, 3.06, and 3.26 per 100,000 population in 2000. The majority (69.62%) of the mortalities of pancreatic cancer was seen in the age group of 60 years and older. The mortality rate was higher in men than in women, but the male to female death rate ratios decreased during the 10 years. Our data also showed that the death rate of pancreatic cancer in urban areas was about 2-4 fold higher than that in rural areas, and in the districts of Northeast and East China, the death rates were higher than those in the other 5 administrative districts. CONCLUSION: The death rate due to pancreatic cancer was rising during the period of 1991-2000 and the peak mortality of pancreatic cancer might arrive in future in China.

Adolescent↗

PubMed2005

[In vivo micronuclei and gene mutation induced by DEN in the lacZ transgenic mouse].

OBJECTIVE: To assess mutagenicity of N-nitrosodiethylamine (DEN) in vivo using the lacZ transgenic mouse (Muta Mouse). METHODS: LacZ gene was recovered through in vitro packing. Mutant frequencies (MFs) in the lacZ gene of liver, lung and bladder were examined after intraperitoneal treatment with DEN (25mg/kg per week x 4). Simultaneously, the clastogenicity of DEN was evaluated by the peripheral blood micronucleus assay. RESULTS: The mean frequency of micronucleated reticulocytes (MNRETs) did not increase by the treatment with DEN. The MFs increase above spontaneous levels were apparent in liver and lung, with respectively 6.13 - and 3.66 fold increase. The MF of lacZ of bladder was of the background level. CONCLUSION: Liver and lung are target organ of genotoxicity in vivo induced by DEN with different sensitivity.

Animals↗