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Biomedical subjects

Li Wang

Publications and source records attributed to Li Wang.

At least 289 records · Page 16Linked to original sources
PubMed2005

[Experimental study of effect of carvedilol on myocardial collagen network remodeling after acute myocardial infarction in rats].

OBJECTIVE: To investigate the effects of carvedilol, irbesartan and their combination on myocardial collagen network remodeling after acute myocardial infarction (AMI) in rats. METHODS: Twenty-four hours after ligating left anterior descending coronary artery, 35 surviving AMI male Sprague-Dawley rats were randomly assigned to control (n=8), carvedilol (n=9, 10 mg.kg(-1).d(-1)), irbesartan (n=9, 45 mg.kg(-1).d(-1)), and carvedilol (10 mg.kg(-1).d(-1)) plus irbesartan (45 mg.kg(-1).d(-1), n=9) groups. Sham operating group was comprised of 8 rats without coronary artery ligation as controls. After 8 weeks of administration of the drug by gastric gavage, hemodynamics and left ventricular function were measured, then the rat hearts were fixed, sectioned, and stained with Sirius red, and pathologically analyzed using polarized light. The total collagen volume density fraction (CVF) and type I and III CVF in the infarcted and noninfarcted zone (IZ/NIZ) were measured by computer-assisted image analysis system. RESULTS: There were no significant differences in myocardial infarction size among the four AMI groups (40.02%-44.70%, P>0.05). Compared with the sham operation group, left ventricular (LV) end diastolic pressure (LVEDP), left and right ventricular relative weight (LVRW/RVRW), the total CVF and the CVF of type I and III in the IZ and NIZ were all significantly higher (P<0.05 or P<0.01), and in contrast, blood pressure, left ventricular systolic pressure (LVSP), the left ventricular pressure maximal rate of rise and fall (+/-dp/dt max) and their adjustment by LVSP (+/-dp/dt max/LVSP) were significantly decreased (P<0.05 or P<0.01). Compared with the control group, LVEDP, LVRW, RVRW, the total CVF and the CVF of type I and III in the NIZ were all significantly decreased (P<0.05 or P<0.01), while +/-dp/dt max and +/-dp/dt max/LVSP were all significantly increased (all P<0.01) in the carvedilol, irbesartan and their combination therapy groups. CONCLUSION: Carvedilol, irbesartan and their combination can all effectively decrease collagen deposition in the NIZ of left ventricle, prevent left ventricular remodeling after AMI in rats, improve hemodynamics and LV function.

Animals↗
PubMed2005

[Regulatory effect of Smad7 gene on MAPK signal pathway in malignant transformation of immortalized human bronchial epithelial BEP2D cells].

BACKGROUND & OBJECTIVE: Smad7 is an inhibitor of transforming growth factor-beta (TGF-beta) signal pathway. TGF-beta could induce the expression of several genes through activating SMAD and ras/MEK/ERK pathways. This study was to determine whether Smad7 is involved in regulating mitogen-activated protein kinase (MAPK) signal pathway with TGF-beta in malignant transformation of human bronchial epithelial BEP2D cells. METHODS: Immortalized BEP2D cells and malignant BERP35T2 cells were co-transfected with full-length Smad7 cDNA constructed pCISmad7.neo or Smad7 siRNA, transactivator vector pTet-Elk or pTet-Jun, and reporter vector pTRE-Luc, and stimulated with TGF-beta. The regulatory effect of Smad7 on MAPK signal pathway was investigated by standard luciferase assay. RESULTS: In BEP2D cells, when treated with TGF-beta1, phosphorylated activities of Elk and Jun were up-regulated (P(Elk)=0.033, P(Jun)=0.016); after co-transfection of Elk or Jun with pCISmad7.neo, phosphorylated activity of Elk was increased, and that of Jun was decreased (P(Elk)=0.017, P(Jun)=0.028); after co-transfection of Elk or Jun with Smad7 siRNA, phosphorylated activity of Elk was decreased, and that of Jun was increased (P(Elk)=0.018, P(Jun)=0.005). In BERP35T2 cells, when treated with TGF-beta1, phosphorylated activity of Elk was up-regulated (P=0.006); after co-transfection of Elk and Smad7 siRNA, phosphorylated activity of Elk was decreased (P=0.000); no activity of Jun was detected in BERP35T2 cells. CONCLUSIONS: In the process of malignant transformation of BEP2D cells, the intervention of Smad7 in MAPK signal pathway leads to the activity imbalance between extracellular signal-related protein kinase (ERK) and c-Jun NH2-terminal kinase (JNK), which in turn promotes cell proliferation. All these could contribute to further malignant transformation of these cells.

Bronchi↗
PubMed2005

[Influence of the expression of heat shock protein 70 in maxillofacial squamous cell carcinoma by thermochemotherapy].

OBJECTIVE: To study the influence of thermochemotheraphy on the expression of HSP70 in maxillofacial squamous cell carcinoma. METHODS: 12 patients were treated with thermochemotheraphy twice a week, altogether 10 times. After 8 mg of Pingyangmycin infused, the patients were treated with microwave hyperthermia at 43 degrees C for 40 min. The part of carcinoma tissue was removed with surgical operations at before treatment and aftre five times of treatment. The expression of HSP70 in tumor cells was determined by SP immunohistochemcial method. RESULTS: The expression of HSP70 in tumor cells was enhanced obviously by thermochemotherapy. CONCLUSION: Special high expression of HSP70 in the tumor cells was induced by thermochemotherapy. With the antigen presenting action and other action, HSP70 have special antitumor effect.

Carcinoma, Squamous Cell↗
PubMed2005

[Study on the effectiveness and cost-benefit of influenza vaccine on elderly population in Beijing city].

OBJECTIVE: To estimate the effectiveness of inactivated influenza vaccine in elderly population. METHODS: An quasi-experimental study was used. 590 elderly people who volunteered to receive the influenza vaccine were served as vaccine group, while 602 persons who did not want to receive the inoculation but could match the vaccine group were served as controls. One baseline and three follow-up surveys were carried out. RESULTS: The protective rates of influenza like ill (ILI) as 52.38%, 36.84% and 37.89% with the decreasing rates of visits to ILI clinic as 45.16%, 50.54% and 50.54% were found after 1 month, 3 month and 6 month of inoculation of influenza vaccine; The protective rates of common cold, other respiratory tract or chronic disease were 49.54%, 64.54%, and 38.82%, respectively. The benefit-cost ratio was 4.98:1 in elderly population. CONCLUSION: Influenza vaccination could decrease ILI incidence and recurrence rates of related chronic diseases on elderly population to provide better economic benefits for the elderly.

Aged↗
PubMed2005

[Preparation of anodic Al2O3 films on SiO2 substrate and their photoluminescence properties].

300 nm thick aluminum films were deposited on SiO2 substrates by heat evaporation. At 0 degrees C, 40 V DC voltage, the authors successfully prepared high density Al2O3 films by anodic oxidation on SiO2 substrates with 15 wt% H2SO4 as electrolyte, and AFM was employed to study the film surface morphology. At room temperature the authors measured the photoluminescence spectrum of Al2O3 films prepared at different anodic voltages excited by Xe lamp. In addition, the authors monitored their excitation spectra of different emission peaks, and the authors found that the relative emission intensity gets weaker and shifts to lower energy at higher anodic voltage. At 40 V anodic voltage the authors observed new 356 nm ultraviolet emission, which has the same 210 nm excitation emission. Based on the discussion of the relative intensity of the PL spectra of anodic alumina at different voltages, the authors suggest that F and F+ oxygen vacancy defects were responsible for the observed 356 and 386 nm ultraviolet photoluminescence from Al2O3 anodic film at 40 V voltage.

Aluminum Oxide↗
PubMed2005

[Deoxycholate induces apoptosis in cultured normal human esophageal mucosal epithelial cells].

OBJECTIVE: To study the effect of deoxycholate in inducing apoptosis of human normal esophageal mucosal epithelial cells in vitro and investigate the molecular mechanism. METHODS: Cultured normal human esophageal mucosal epithelial cells were treated with deoxycholate, and the cell apoptosis were evaluated with TUNEL, DNA ladder, flow cytometry with PI-staining, Annexin V-FITC conjugated with PI staining, and Western blotting. RESULTS: Flow cytometry, TUNEL and DNA ladder demonstrated that deoxycholate could induce apoptosis in normal human esophageal mucosal epithelial cells in a dose- and time-dependent manner. A percentage of 21.3% of the cell population treated with deoxycholate at 500 micromol/L for 30 min exhibited detectable caspase-3 activity shown by flow cytometry, which was significantly higher than the control level (1.5%, P<0.01). Western blotting suggested that deoxycholate down-regulated Bcl-2 protein expression and up-regulated Bax expression, but Fas was negative in the cells before and after deoxycholate treatment. CONCLUSIONS: Deoxycholate could induce apoptosis in cultured human esophageal mucosal epithelial cells. Aaspase-3 activation, Bcl-2 protein down-regulation and Bax up-regulation are involved in deoxycholate-induced apoptosis, which does not involve Fas-L/Fas.

Apoptosis↗
PubMed2005

[Determination of amino acids in fu fang banlangen granulae by a pre-column derivatization RP-HPLC method].

OBJECTIVE: To establish a pre-column derivatization reversed-phase high-performance liquid chromatographic method for the determination of amino acids, which was known as the characteristic constituents of Fu Fang Banlangen Granulae. METHODS: We determined the amino acids in alkalescence by a pre-column derivatization of DNFB. NaAc buffer (pH 6.4)-Acetonitrile (850:150) was used as the mobile phase on a SinoChrom ODS-BP column. The detector was operated at 360 nm. RESULTS: The method was carried out over the range of 0.627 - 5. 016 microg for Arg and 0.874 - 7.000 microg for Pro. The recoveries were 97.7% with the RSD = 2.0% for Arg and 97.7% with the RSD = 1.5% for Pro. CONCLUSIONS: The method has good accuracy and repeatability and it can be used for the quality control of Fu Fang Banlangen Granulae.

Amino Acids↗
PubMed2005

[In vitro transdermal permeation of lidocaine-dodecanol binary eutectic system].

AIM: To study the effect of lidocaine-dodecanol binary eutectic system on the transdermal permeation of lidocaine. METHODS: Binary eutectic mixture of different proportions of lidocaine and dodecanol were prepared and the patch containing the binary eutectic mixture was developed. The solubilities of pure lidocaine and lidocaine from the binary eutectic system were determined in pH 7.9 phosphate buffer. The transdermal flux of lidocaine from the patches containing the binary eutectic system and pure lidocaine were measured using Franz-type single diffusion cell. RESULTS: The melting point of the lidocaine-dodecanol binary eutectic system was markedly lower than that of pure lidocaine. The steady state transdermal flux of lidocaine from the patch of the binary eutectic system was six times as much as that of pure lidocaine patch. CONCLUSION: The lidocaine-dodecanol binary eutectic system could produce high thermodynamic activity of the drug and the high driving force for transdermal permeation of lidocaine.

Administration, Cutaneous↗
PubMed2005

[Observation on clinical therapeutic effect of "mother-son" reinforcing-reducing method on stroke at restoration stage].

OBJECTIVE: To probe into the role of "mother-son" reinforcing-reducing method of five Shu points in clinical treatment of stroke at restoration stage. METHODS: Sixty-six cases of stroke were randomly divided into a treatment group (n = 34) and a control group (n = 32). The treatment group were treated by acupuncture at acupoints of The Hand-Yangming and The Foot-Yangming Channels, and "mother-son" reinforcing-reducing method of the five Shu for reinforcing deficiency and reducing excess according to deficiency and excess of channels differentiated by Cunkou Renying diagnosis; the control group were treated only by acupuncture at acupoints of The Hand-Yangming and Foot-Yangming Channels with uniform reinforcing-reducing method. Blood flow velocity in Cunkou and Renying Vessels before and after treatment were determined with transcranial Doppler ultrasono-blood flow meter and their clinical therapeutic effects were compared. RESULTS: There was a very significant difference before and after treatment in blood flow velocity in Cunkou and Renying vessels in the treatment group; the clinically basic recovery and markedly improving rate after treatment in the treatment group was significantly superior to that in the control group (P < 0.01). CONCLUSION: The acupuncture therapy of "mother-son" reinforcing-reducing method of five Shu points based on differentiation of yin, yang and deficiency and excess of channels by Cunkou and Renying Vessel methods can increase clinical therapeutic effect on stroke at restoration stage.

Acupuncture Points↗
PubMed2005

[Influence of novel surface treatment of ITO anodes on the performance of OLED].

The influences of surface treatments of indium-tin-oxide (ITO) anodes on the performance of OLED devices were investigated. This surface treatment is mechanical processes using a novel nanometer powder. Their surface morphology was measured by scanning using an AFM (atomic force microscope). The number and size of spike was reduced and regulation of ITO was enhanced; brightness and efficiency of devices were obviously increased. This novel way for ITO surface treatment by mechanical processes was proven to be effective.

Electrochemical Techniques↗
PubMed2005

[Progress in developmental toxicity of methylmercury].

Mercury is a common pollutant in the environment and it can be turned into methylmercury (MeHg) under the metabolism of microbe. MeHg is a confirmed teratogen in human. It can impair the germ cells and influence the growth and development of the offspring. MeHg can easily pass through the placental barrier, accumulate in the fetus and change the behavior and perceptibility of the second generation related to the function of central nervous system. Recently, the investigations on the mechanism about developmental toxicity of MeHg have progressed much, so we make a review in this field as follows.

Animals↗
PubMed2005

[The reform in otolaryngology teaching and some lessons learned from it].

OBJECTIVE: To summarize the experiences in otolaryngology teaching for seven year education system students in class 2000 at Peking University Third Hospital during a period of noviciate. METHOD: A reform of the current teaching model was put in practice, which includes redesigning curriculum, increasing the amount of clinical time, teaching on a small group base, emphasizing note-taking, and discussing with the use of problem-oriented clinical note. RESULT: The students received higher clinical grades and more clinical skills. They were more likely to retain their initial interest in or switch their preference to careers in otolaryngology. CONCLUSION: The teaching reform successfully promotes student interest in otolaryngology, and markedly increases the quality of otolaryngology teaching.

Curriculum↗
PubMed2005

[Determination of glycyrrhizic acid in glycyrrhiza uralensis fisch by fiber optic near infrared spectroscopy].

The objective of this study was to develop a rapid, non-destructive and real-time method for the determination of glycyrrhizic acid in glycyrrhiza uralensis fisch. Near infrared spectra (NIR) in the range of 10 000-4 000 cm(-1) were recorded for the glycyrrhiza uralensis fisch containing glycyrrhizic acid in the content of 0.94 %-3.06%. Calibration models were established using the PLS (partial least squares) and PCR (principle component regression) algorithm. Different spectra pretreatments methods were compared. The study showed that PLS model gave better results than PCR with the correlation coefficient 0.958, SEC 0.179 (standard deviation of the calibration sets) and SEP 0.197 (standard deviation of the prediction sets). Results indicate that fiber optic NIR method can be used to on-line control the valid component in Chinese herbs.

Calibration↗
PubMed2005

[Study on rhG-CSF modified with polyethylene glycol].

Monomethoxy Polyethylene Glycol(mPEG20000) was activated by N-hydroxysuccinimede and analyzed by infrared spectrum and hydrolysis kinetics. In order to propose the optimized reaction conditions of mono-PEGylated rhG-CSF, orthogonal design of the experiment was investigated. Ion exchange chromatography was used to separate and purify PEGylated rhG-CSF from unPEGylated rhG-CSF. The purity of mono-PEGylated rhG-CSF was analyzed by high performance liquid chromatography (HPLC) to be 97%.

Granulocyte Colony-Stimulating Factor↗
PubMed2005

[Pilot study on the mechanisms of growth inhibitory effect of cinobufagin on HeLa cells].

OBJECTIVE: To study the effect of cinobufagin (CBG) on HeLa cell proliferation, and to analyze its mechanism. METHODS: Proliferation inhibition in vitro was evaluated by MTT and Sulforhodamine B (SRB) assays in several human tumor cell lines, including Bel-7402, HeLa, MCF-7, BGC-823 and HL60. The cycle of HeLa cells was analyzed by flow cytometry. Two-dimensional electrophoresis was applied to analyze the influence of CBG on HeLa cell proteomics. RESULTS: CBG had inhibitory effects on proliferation of five human cancer cell lines, and the IC(50) values were 0.011 micromol/L (Bel-7402), 0.019 micromol/L (HeLa), 0.116 micromol/L (MCF-7), 0.149 micromol/L (BGC-823) and 1.369 micromol/L (HL60), respectively. HeLa and Bel-7402 cells were among the most sensitive. Flow cytometry assay indicated that the treatment of HeLa cells with various concentrations of CBG for 72 h was able to increase the cell number at G(2)/M phase, from 17.3% up to 35.6%. The results of two-dimensional electrophoresis showed that treatment of HeLa cells with 0.02 micromol/L CBG for 48 h resulted in apparent changes of certain small molecular weight (30,000 - 90,000) acidic proteins (pH 4 - 6). CONCLUSION: Cinobufagin has significant inhibitory effect on growth of five human cancer cells in vitro. It may lead to cell cycle arrest of HeLa cells at G(2)/M phase. It can also change the expression of some small molecular acidic proteins in HeLa cells.

Antineoplastic Agents↗
PubMed2004

Vitamin K acupuncture pint injection for severe primary dysmenorrhea: an international pilot study.

CONTEXT: Vitamin K acupuncture point injection, a menstrual pain treatment derived from traditional Chinese medicine, has been a standard treatment in some hospitals in China since the 1980s. OBJECTIVES: To investigate the effects of vitamin K acupuncture point injection on menstrual pain in young women aged 14 to 25 from different countries and cultural backgrounds who have had unmitigated severe primary dysmenorrhea for 6 months or more. DESIGN: Prospective, observational, clinical pilot study SETTINGS: One site in China (a hospital outpatient clinic in Shanghai) and 2 sites in Italy (a hospital clinic in Milan and a private gynecology practice in Verona). INTERVENTIONS: All subjects were treated with bilateral acupuncture point injection of vitamin K on the first or second day of menstrual pain. Vitamin K3 was used in China and vitamin K4 in Italy. MAIN OUTCOME MEASURES: Pain intensity, total duration, and average intensity of menstrual distress, hours in bed, normal daily activity restrictions, and numbers of analgesic tablets taken to relieve pain were recorded before the treatment and for 4 subsequent menstrual cycles. RESULTS: Noticeable pain relief was observed 2 minutes after treatment, and subsequent pain reduction occurred at 30 minutes (P < .001). Subjects reported significantly fewer daily life restrictions, fewer hours in bed, less consumption of analgesic tablets, and lower scores of menstrual pain duration and intensity (P < .001). There were no adverse events. Some women experienced mild, self-limited pain at the injection site. CONCLUSION: Acupuncture point injection with vitamin K alleviated acute menstrual pain, and relief extended through the nontreatment follow-up cycles in this uncontrolled pilot study conducted in 2 countries. Further investigation employing controlled experimental designs is warranted.

Acupuncture Points↗