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Li Wang

Publications and source records attributed to Li Wang.

At least 469 records · Page 26Linked to original sources
PubMed2002

Possible involvement of P-glycoprotein in the biliary excretion of grepafloxacin.

1. In the present study, we have examined the effects of the quinolones norfloxacin (NFLX), enoxacin (ENX), ofloxacin (OFLX), tosufloxacin (TFLX), lomefloxacin (LFLX), sparfloxacin (SPFX) and grepafloxacin (GPFX) on the efflux of doxorubicin from mouse leukaemia P388/ADR cells expressing P-glycoprotein. The relationship between their partition coefficients (hydrophobicity) and effluxing potencies was also elucidated. 2. Both TFLX and SPFX strongly increased the intracellular accumulation of doxorubicin (5 micromol/L) in P388/ADR cells, but had no effect on P388/S cells not expressing P-glycoprotein. The rank of order of the potency of the quinolones (TFLX > SPFX > GPFX > NFLX) was not related directly to their hydrophobicity. These results suggest that some quinolones can reverse anticancer drug resistance. 3. Because GPFX is more highly excreted into the bile than other known quinolones, the effects of doxorubicin (10 mg/kg) or the well-known inhibitors of P-glycoprotein, namely cyclosporine A (10 mg/kg) and erythromycin (100 mg/kg), on the biliary excretion of GPFX at steady state was studied in rats. 4. Doxorubicin, cyclosporine A and erythromycin significantly decreased the biliary clearance of GPFX. Cyclosporine A and erythromycin had a much stronger inhibitory effect on the biliary excretion of GPFX than doxorubicin. These results suggest the possibility that GPFX is, at least in part, excreted into the bile by a P-glycoprotein-mediated transport mechanism.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Predictors of functional change: a longitudinal study of nondemented people aged 65 and older.

OBJECTIVES: To identify factors associated with functional change in an older population and investigate interactions among selected potential risk factors. DESIGN: A population-based prospective cohort study. SETTING: A random sample was selected from the Group Health Cooperative members in the Seattle area from 1994 to 1996 and followed biennially. PARTICIPANTS: Two thousand five hundred eighty-one people aged 65 and older, cognitively intact at baseline. MEASUREMENTS: Functional status was measured by activities of daily living, instrumental activities of daily living, and performance-based physical function testing. RESULTS: The cohort status at the time of these analyses was: deceased, 391; withdrawn, 179; dementia, 152; and on study, 1,873. The mean follow-up time was 3.4 years. Using linear regressions with Generalized Estimating Equation, selected medical conditions (diabetes mellitus, hypertension, coronary heart disease, cerebrovascular disease (CVD), osteoporosis, arthritis, and cancer), low cognitive function, depression, and smoking were associated with worse functional outcomes. Exercise and moderate alcohol use were associated with better functional outcomes. Over the follow-up period, coronary heart disease, CVD, and depression were associated with increased rates of functional decline. Exercise and moderate alcohol consumption were associated with decreased rates of functional decline. Significant interactions were observed between exercise and coronary heart disease, moderate alcohol use and CVD, and cognition and CVD. CONCLUSIONS: Our study has identified not only risk factors associated with functional decline but also the interactions among these factors. These observations, along with other published research, add to the growing understanding of the underlying process of functional change and could provide a basis to design effective strategies to delay functional decline.

Activities of Daily Living↗
PubMed2002

Modification of adriamycin pharmacokinetics by direct electric current in rats.

Adriamycin (ADR, doxorubicin), a drug having cardiotoxicity, is electrically charged as a cation in blood. We therefore investigated whether iontophoresis caused by direct electric current (DC; 50 microA, 90 min) would cause systemic modification of ADR pharmacokinetics. Cathode and anode were placed into a right kidney and muscles of the abdominal wall, respectively, in six Donryu rats. Urinary excretion of ADR, as measured by catheterizing into the right kidney, was significantly higher in the DC group than in the controls (p < 0.05). Both plasmic and renal ADR clearances were significantly higher in the DC group (p<0.005 and p<0.001, respectively). Tissue ADR concentrations were significantly lower in the DC group (heart: p<0.003; liver and lung: both p<0.05). These results suggest that electric therapy might potentially induce modification of ADR pharmacokinetics by iontophoresis, and that the therapy might effectively change ADR concentration both locally and systemically.

Abdominal Muscles↗
PubMed2002

Pharmacokinetic and pharmacodynamic effects of clonazepam in children with epilepsy treated with valproate: a preliminary study.

The authors report the use of the quantitative pharmaco-EEG (QPEEG) technique to study the pharmacokinetics (PK) and pharmacodynamics (PD) of clonazepam (CZP) in four epileptic children who suffered uncontrolled seizures despite long-term valproate (VPA) therapy. After a single dose of CZP (0.05 mg/kg, PO), blood samples were collected at 0, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 8.0, 12.0, and 24.0 hours. CZP and VPA concentrations were measured by HPLC or GC assay, respectively. At each blood collection time point, EEG signals (60 s) were recorded for brain electrical activity mapping, and the power percentage average (PPA) of each frequency band was calculated. The relationship between drug concentrations and their corresponding PPA of each frequency band was analyzed. VPA steady-state drug concentrations (Css) were within the therapeutic range and not affected by CZP. The peak concentration (Cmax) of CZP and the time intervals from dosing to Cmax (Tmax) were 20.9 ng/mL to 113.8 ng/mL and 1 hour to 1.5 hours, respectively. There was no significant correlation between VPA concentrations and the PPA of any of the EEG frequency bands. CZP blood concentrations showed significant correlation with PPA in 3 of the 4 patients. Our results suggested CZP could affect fast wave activities in proportion to CZP blood concentrations. We propose that QPEEG is a promising technique to study the PK and PD of selected anti-epileptic drugs.

Adolescent↗
PubMed2002

Induction of alpha-catenin, integrin alpha3, integrin beta6, and PDGF-B by 2,8-dihydroxyadenine crystals in cultured kidney epithelial cells.

BACKGROUND: Homozygous adenine phosphoribosyltransferase (APRT) deficiency is associated with 2,8-dihydroxyadenine (DHA) nephrolithiasis. Using whole kidney RNA from Aprt knockout mice, we previously showed that the renal deposition of DHA leads to changes in the expression of genes involved in tissue injury. To determine the cellular basis for these changes, we investigated gene expression in cultured human kidney (NHK-C) and African green monkey (BSC-1) epithelial cells exposed to DHA or calcium oxalate monohydrate (COM) crystals. METHODS: First-strand cDNAs, synthesized from mRNA isolated from treated and untreated cells, were hybridized to membrane-bound cDNA arrays containing 588 genes associated with various physiological and pathological processes. Changes in gene expression were confirmed by reverse transcription PCR. RESULTS: Twenty-seven percent of the array cDNAs were expressed in untreated NHK-C cells at varying levels relative to a housekeeping gene. The expression of three adhesion molecules (alpha-catenin, integrin alpha3, and integrin beta6) and platelet-derived growth factor B (PDGF-B) was elevated following exposure of NHK-C cells to DHA. Increased expression of the adhesion molecules was also observed in BSC-1 cells, but PDGF-B expression could not be detected. COM crystals also stimulated the expression of these four genes in NHK-C cells, but the expression profile was quantitatively different compared with DHA. CONCLUSIONS: These findings suggest that DHA crystals stimulate the expression of specific genes in kidney epithelial cells and that the pathways for DHA-induced cell injury may be similar to those for COM crystals. The induction of adhesion molecules and PDGF-B may affect cell-cell or cell-matrix interactions and/or alter the actin cytoskeleton. These alterations may ultimately contribute to crystal-induced renal injury.

Adenine↗
PubMed2002

Intravenous chemotherapy for resected gastric cancer: meta-analysis of randomized controlled trials.

AIM: To assess the safety and efficacy of different intravenous chemotherapeutic regimens in patients with gastric carcinomas who had undergone gastrectomy. METHODS: A meta-analysis of all the relevant randomized controlled trials (RCTs) was performed. Language was restricted to Chinese and English. RCTs were identified from Medline and Embase (1980-2001/4), and Chinese Bio-medicine Database (1990-2001/1). Literature references were checked at the same time. We included randomized and quasi-randomized trials comparing the efficacy of intravenous chemotherapy after gastrectomy with that of surgery alone in patients with confirmed gastric carcinomas who had undergone gastrectomy. Selection criteria were: randomized or quasi-randomized trials with following-up results; Trials could be double-blind, single-blind or not blind; Chemotherapy groups were given intravenous chemotherapy after gastrectomy without neo-adjuvant chemotherapy, intraperitoneal hyperthermic perfusion, radiotherapy or chemoimmunotherapy; Controlled group included those receiving gastrectomy alone. The following data were extracted: the number of survival and death by the end of the follow-up; the different agents and doses of the intravenous chemotherapy; the baseline of the chemotherapy group and the controlled arm; the serious adverse events; the statistical consideration; cost-effectiveness analysis. The statistical analysis was performed by RevMan4.1 software which was provided by the Cochrane Collaboration. A P value of <0.05 was considered statistically significant. Meta-analysis was done with random effects model. Heterogeneity was checked by chi-square test. Sensitivity analysis was performed by excluding the trials in which Jadad-scale was only 1 score. The result was expressed with odds ratio (OR) for the categorical variable. RESULTS: Fourteen trials involving 4543 patients were included. Meta-analysis was done with random effects model. Heterogeneity and sensitivity analysis were performed also. The effect of intravenous chemotherapy after gastrectomy was better than surgery alone (odds ratio 0.56, 95 %CI 0.40-0.79). There was a significant difference between the two groups by u-test (P=0.0008). Sensitivity analysis revealed the same difference (odds ratio 0.81, 95 % CI 0.70-0.94). Of fourteen trials, only three studies were of high quality according to the Jadad-scale (with three score). There was one meta-analysis trial and the others, about ten trials, were of low quality. There was no trial which mentioned sample-size calculation, allocation concealment, intention-to-treat analysis. Most of the trials didn't describe the blind-procedure. There were five trials which detailed the side-effects according to the toxicity grade by WHO standard. The side-effects halting treatment were haematologic and biochemical toxicity, debilitating nausea and vomiting. There were two patients died of chemotherapy toxicity. CONCLUSION: Based on the review, intravenous chemotherapy after gastrectomy may have positive treatment effect on gastric cancer. However, the evidence is not strong because of the general low methodologic quality of the RCTs. Therefore, we can't make the conclusion that intravenous chemotherapy after gastrectomy may have better treatment effect on gastric cancer than that of surgery alone. Rigorously designed, randomised, double-blind, placebo-controlled trials are required.

Antineoplastic Agents↗
PubMed2002

[Hairy-root culture of Polygonium multiflorum Thunb. and the production of its active constituents-anthraquinones].

Transformed hairy roots of Polygonium multiflorum Thunb. were obtained by the transformation of Agrobacterium rhizogenes LBA9402. It was clearly demonstrated that T-DNA of A. Rhizogenes Ri plasmid was integrated into the cells of hairy roots by the experiments of PCR and Southern hybridization. Through the screen of basic medium and the research of growth curve of hairy roots, the optimum inoculum time was selected in 30 days or so in the optimum condition-MS medium. On the condition, the content of rhein was 2.85 folds higher in hairy roots than that of natural plants by means of HPLC.

Anthraquinones↗
PubMed2002

[An experimental study for fixation of CO2 in stack gases using microalgae cultivation].

To obtain a microalgae growing well in the condition of stack gases and to find a good method of fixing greenhouse gases, the ZY-1 strain identified as a species of Chlorella genus was isolated from soil-water mixture samples collected from a paddy field after an enrichment culture using the reproduced stack gases containing 15% of CO2 and 2% of O2. The results showed that the range of CO2 concentration for the optimum growth of the ZY-1 strain was 10-15%. The ZY-1 strain had its maximum growth when the CO2 concentration was 10%. Under a broad range of physically conditions including 0.25-0.75 L.min-1 of air flowing rate, 25-30 degrees C of temperature and pH 4-6, the ZY-1 strain had a steady growth. The optimum cultural condition with 0.397% of the CO2 utilization efficiency was seemed to be 10% of CO2, 25 degrees C and pH 5.0. It is feasible to fix greenhouse gases using the stack gases combined with the ZY-1 strain.

Carbon Dioxide↗
PubMed2002

[The selecting experiment of resistance to Marek's disease of chicken].

The Marek's Disease is an acute infectious disease in poultry production. The selecting experiment through blood-group gene inspection of adult parents and attack-test by using of Marek's Disease virus (MDV) for offspring chicks was carried out. The results showed as follows: (1) The rates of positive reaction by No. 614 blood-group gene inspection of adult parents in four generations were increased due to generation increase, as F0-68.8%, F1-77.3%, F2-81.8% and F3-90.5%. (2) In the attack-test by using of MDV at 10 days of age of chicks the mortalities of the experimental group at 60 days of age of chicks whose parents have positive reaction by No. 614 blood-group reagent detect in F2-F4 generations were 25.8%, 69.2% and 29.4% respectively, while the mortalities of the control group at same age of chicks whose parents have negative reaction were 30.6%, 81.0% and 52.9% respectively. These differences of mortality were significant (P < 0.01 or P < 0.05). (3) The rates of pathological change of 9 viscera tumor of the experimental group chicks in F2-F4 generations were 87.6%, 83.3% and 58.8% respectively, while chicks in the control group were 88.1%, 84.5% and 70.6% respectively. Except individual generation and viscera, these differences between the experimental group and the control group were almost not significant (P > 0.05). The experimental results and genetic control of resistance to Marek's Disease are discussed in this paper. The new strain of chicken resistant to Marek's Disease will be bred.

Animals↗
PubMed2002

[A novel rhodopsin E341ter mutation in patients with retinitis pigmentosa and corresponding clinical phenotype].

OBJECTIVE: To detect rhodopsin (RHO) mutation in Chinese families with autosomal dominant retinitis pigmentosa (ADRP) and study on the association of RHO gene mutations with clinical phenotype. METHODS: Twenty-seven members from 13 Chinese families with ADRP and 30 normal subjects were recruited. The complete coding regions of the rhodopsin gene were amplified with polymerase chain reaction (PCR) and then DNA single-strand conformation polymorphism (SSCP) technique was used to screen RHO gene mutations. When a variant band was observed after the SSCP electrophoresis, the variant band was analyzed by sequencing PCR-amplified DNA. All subjects were examined clinically by slit-lamp, direct funduscopy, Goldmann kinetic perimetry, Humphrey threshold perimetry and electroretinogram. RESULTS: Nine affected subjects and 2 boys (11 and 9 years old respectively) in one pedigree among 13 families were found to have three DNA single strand bands by SSCP analysis. Results of assaying sequence showed the 11 members were heterozygous for rhodopsin E341ter mutation. The codon 341 is changed from GAG to TAG, resulting in a stop codon mutation. Thirty normal controls and unaffected subjects in this family were the wild type of RHO gene. Affected individuals reported night blindness in the second decade, showed optic atrophy, vessel attenuation and a few bone spicule-like pigments in the peripheral retina. The impairment of visual acuity was relatively severe, loss of peripheral visual field was greatly considerable after 30 years of age, rod and cone ERG were not detectable in the second decade, and only slight cone response was left. CONCLUSIONS: The natural history of RP in this family begins with a loss of rod function, progresses to involve the cone system, and leads eventually to a severe loss of visual function. A novel rhodopsin gene mutation E341ter is responsible for a Chinese family with ADRP.

Adult↗
PubMed2002

AIDS-related knowledge, condom usage among medical postgraduates.

OBJECTIVE: To investigate the knowledge about safety/unsafety of sexual acts relating to HIV transmission, levels of embarrassment related to condom and condom usage among medical postgraduates. METHODS: From August to December, 1998, a self-administered anonymous questionnaire was given to 271 new medical postgraduates from two medical colleges of Beijing and Hebei Province. RESULTS: There was a hazy understanding of the protective function of condom from AIDS among medical postgraduates. Only 14.4% medical postgraduates persisted in using condom, and 27.94% had never or almost never used it. The levels of embarrassment about condom were high. The median score was 3.55 +/- 0.98. Whether to use condom was related with the attitudes to condom, but not to AIDS. CONCLUSION: There was some misunderstanding about condom and inconsistent condom usage in medical postgraduates. So it is essential to strengthen the sexual health education among them.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Proapoptotic and antitumor activities of adenovirus-mediated p202 gene transfer.

PURPOSE AND EXPERIMENTAL DESIGN: p202, a mouse IFN-inducible protein, is a member of the 200-amino acid repeat family. Enforced p202 expression in stable cancer cell lines resulted in growth inhibition in vitro and tumor suppression in vivo. However, to study the immediate effect of p202 and test the potential efficacy of p202 treatment, an efficient gene delivery system for p202 is required. For these purposes, an adenoviral vector expressing the p202 gene (Ad-p202) was generated. We examined the effects of Ad-p202 infection on human breast cancer cells. Furthermore, we tested the efficacy of Ad-p202 treatment on breast and pancreatic cancer xenograft models. RESULTS: We found that Ad-p202 infection induces growth inhibition and sensitizes the otherwise resistant cells to tumor necrosis factor alpha-induced apoptosis. In addition, we demonstrated for the first time that Ad-p202 infection induces apoptosis and that activation of caspases is required for the full apoptotic effect. More importantly, we showed the efficacy of Ad-p202 treatment on breast cancer xenograft models, and this antitumor effect correlated well with enhanced apoptosis in Ad-p202-treated tumors. CONCLUSIONS: We conclude that Ad-p202 is a potent growth-inhibitory, proapoptotic, and tumor-suppressing agent. Ad-p202 may be further developed into an efficient therapeutic agent for human cancer gene therapy.

Adenoviridae↗
PubMed2002

[Experimental study of monoclonal antibody to intercellular adhesion molecule-1 for incipient acute tubular necrosis].

OBJECTIVE: To explore the role of leukocyte adhesion in the pathophysiology of glycerol-induced acute renal tubular necrosis (ATN). METHODS: Rat models of ATN were established by intramuscular injection of glycerol in 24 Wistar rats, which were divided randomly into 3 groups of equal number according to the agents coinjected with glycerol for the prevention of ATN, with another 8 rats serving as normal control. One of the 3 groups received a monoclonal antibody (mAb) against intercellualr adhesion molecule-1 (anti-ICAM-1) and another received CD3 mAb, leaving one group untreated. Both functional impairment and histological changes in the rats were observed. RESULTS: Plasma creatinine measured 24 h after the injection of glycerol was 412.31+/-94.42 micromol/L in rats treated with anti-ICAM-1, significantly lower than that in CD3 mAb-treated rats (990.21 +/-171.25 micromol/L, P<0.05). Moderate to severe necrosis in the outer renal medulla with frequent mitoses was present in rats with ATN receiving CD3 mAB or nothing, but only mild necrosis with few mitoses occurred in merely 2 of those rats with anti-ICAM-1 treatment. CONCLUSION: Leukocytes and adhesion molecules play critical roles in the pathophysiology of glycerol-induced ATN, and anti-ICAM-1 which blocks the adhesion of the leukocytes may alleviate the pathological changes in the kidney.

Animals↗
PubMed2002

Comparison of anticoagulation efficacy and clinical safety between imported and domestically manufactured low-molecular-weight heparin during hemodialysis.

OBJECTIVE: To compare the anticoagulation efficacy and clinical safety of domestically manufactured and imported low-molecular-weight-heparin during hemodialysis. METHODS: Sixty patients on hemodialysis were randomly divided into 2 groups, who received intravascular injections of domestically manufactured or imported low-molecular-weight heparin to prevent coagulation. Active partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT) and factor Xa activity were determined during dialysis. RESULTS: No incidence of major bleeding was encountered in all of these patients. Similarly low incidences of clotting in extracorporeal circuit were found in either group. No significant differences in aPTT, PT, TT and plasma levels of factor Xa were observed between the two groups. CONCLUSION: Low-molecular-weight heparin domestically manufactured is safe and efficient for anticoagulation during hemodialysis as compared with the imported heparin.

Adult↗
PubMed2002

[Survey on vitamin A deficiency in children under-6-years in China].

OBJECTIVE: To understand the prevalence and spatial distribution of vitamin A deficiency (VAD) in China among children at ages under six years. METHODS: About 8,600 children under 6 years of age in 14 cities and 28 counties of 14 provinces were selected with stratified cluster sampling for survey, including interview with questionnaire for their family information and nutritional status. Blood specimens were collected for measuring serum level of VA with fluorescent spectrophotometry in laboratory. RESULTS: Totally, 8,669 children under 6 (2,877 in urban area and 5,792 in rural area) were surveyed in 14 provinces, with 4,629 males and 4,040 females. Eight cases of night blindness and seven cases of xerophthalmia were found among the children at ages of two to five years. Sixty-one mothers of the children in this group were also found suffering from night blindness. All the cases of night blindness and xerophthalmia both in children and mothers were living in rural areas. Based on their serum levels of VA, 11.7% of the all 1 018 children were diagnosed as VAD, with serum VA concentrations below or equal to 0.70 micro mol/L. Prevalence of VAD was 15.0% and 5.8% in rural (23.3% in the poverty-stricken counties) and urban areas, respectively, and 5.8%, 11.5% and 16.8% in the coastal, inland and remote areas, respectively. The average serum level of VA was 1.20 micro mol/L and 0.99 micro mol/L for urban and rural areas, respectively, with a national average of 1.06 micro mol/L. And, babies under six months of age with an average serum levels of VA < or = 0.70 micro mol/L accounted for 33.4%, and those at ages of four to five years with the same level of VA accounted for 8%. There was significant difference in serum levels of VA between ages, but no significant difference between genders. CONCLUSION: VAD did exist in children of China, especially in the remote and poverty-stricken rural areas and VA supplementation is urgently needed for the children in these regions.

Child↗
PubMed2002

Seroprevalence of porcine circovirus type 2 in swine populations in Canada and Costa Rica.

Porcine circovirus (PCV) was recently divided into 2 antigenically distinct types that differ (65% amino acid identity) in the protein encoded by open reading frame 2 (ORF2). Porcine circovirus 1 is apparently non-pathogenic and, in contrast, PCV2 is associated with porcine multisystemic wasting syndrome (PMWS). Our objective was to determine the extent of exposure of normal pigs in Canada and Costa Rica to PCV2. Recombinant DNA techniques were used to produce an antigen from ORF2 of PCV2 that was suitable for the detection of antibody in swine sera. The presence of PCV2 nucleotide sequences was detected using polymerase chain reaction (PCR) techniques. Using these tests, specific antibody and nucleotide sequences were demonstrated in sera from a cohort of pigs during a PMWS outbreak. Antibody was detected in normal, healthy hogs slaughtered in Canada (82.4% of 386) and in Costa Rica (14.6% of 322). This is the first report indicating the presence of PCV2 in Latin America. More than 50% of these sera also contained PCV2 nucleotide sequence. Although these hogs were healthy when slaughtered, they were infected with PCV2 and may have previously been ill. The widespread occurrence of PCV2 in swine suggests that this virus is adapted to replication in porcine tissue.

Animals↗
PubMed2002

[Induction of petal-like structures from petals of Crocus sativus L. and the differentiation of style-stigma-like structures in vitro].

Firstly the petal of Crocus sativus L was cultured on the medium that supplemented with different combinations of hormones. The petal-like structures(PLS) were induced on medium, but the induction rates were different in various medium. The highest induction rate of petal-like structures was obtained on the media that was supplemented with NAA (4 mg/L) and KT (8 mg/L). The petal-like structures were subcultured on another media when the structure was produced on the explants and proliferate groups. The later media was used for inducing style-stigma-like structures(SSLS). The induction rate of style-stigma-like-structures in the petal-like structures group is much higher than the rate in the preceding work, and the maximum of style-stigma-like structures produced per explant was 30. The best result of style-stigma-like structures was observed on the petal-like structure groups which came from the third treatment. The differentiation rate of style-stigma-like structures is stable in the subcultures of petal-like structures. The result revealed that the induction frequency of style-stigma-like structures formed on the petal-like structures is higher than that form on the petals of C. sativus L.

Cell Differentiation↗