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Biomedical subjects

Wei Liu

Publications and source records attributed to Wei Liu.

At least 127 records · Page 7Linked to original sources
PubMed2006

Pretreatment with transmyocardial revascularization might improve ischemic myocardial function performed with cell transplantation.

BACKGROUND: Cells transplanted into the myocardial infarct areas might be lost because of the lack of blood supply to these myocardium areas. The hypothesis that pretreatment with angiogenic therapy induced by transmyocardial revascularization (TMR) might improve ischemic myocardial function, followed by cell transplantation was tested. METHODS AND RESULTS: After the ligation of the left anterior descending coronary artery, rats were treated with TMR. Two weeks, embryonic stem cells were transplanted into an injured heart. Four weeks after cell transplantation, cardiac function was assessed by homodynamic measurements. Capillary density and infarct size in the infarct myocardium were measured by using a previous experimental method. Graft histology and morphology was also evaluated. Four weeks after the operation, myocardial infarct (MI) rats treated with TMR and cell transplantation showed significantly higher cardiac function in hemodynamic measurements (p < 0.01) than that of MI rats receiving cell transplantation or TMR alone. A significant increase in capillary density and reduction in infarct size was observed in the MI rats that received a combined therapy (p < 0.01). CONCLUSION: Pretreatment of an infarct region of the heart with angiogenesis induced by TMR can enhance the efficacy of a cell graft and attenuate the progression of cardiac dysfunction in the rat model.

Angiogenic Proteins↗
PubMed2006

[Genetic diversity of Dactylis glomerata germplasm resources detected by Inter-simple Sequence Repeats (ISSRS) molecular markers].

Inter-simple Sequence Repeat (ISSR) molecular markers were used to detect the genetic diversity among 50 materials of Dactylis glomerata collected from China and other countries. Twelve primers produced 101 polymorphic bands, averaged 8.41 bands each primer pair. The average percentage of polymorpgic bands was 86.3.8%, and the range of GS (define) was 0.6116-0.9290, indicating a rich genetic diversity of D. glomerata. Based on the cluster and principal component analyses on the genetic characteristics, D. glomerata could be divided into 5 groups according to the nearest phylogenetic relationship. In most cases, accessions from the same continent were classified into the same group, the accessions from China and the United States belong to the different groups, respectively, indicating the geographical distribution of genetic diversity of D. glomerata. The present paper also discussed collection and conservation of germplasm resources in D. glomerata.

Conservation of Natural Resources↗
PubMed2006

Patterns of HIV prevalence and HIV risk behaviors among injection drug users prior to and 24 months following implementation of cross-border HIV prevention interventions in northern Vietnam and southern China.

In 2002, we implemented a 4-year HIV prevention intervention for injection drug users (IDUs) in Lang Son Province, Vietnam, and Ning Ming County, Guangxi Province, China, a cross-border region seriously affected by inter-twined epidemics of heroin injection and HIV infection. The interventions involve peer education on HIV risk reduction and provision of new needles/syringes through direct distribution and pharmacy vouchers. We consider this to be a structural intervention in which risk reduction information and sterile injection equipment are diffused through the IDU populations and not limited to those who actually interact with peer educators. The evaluation of structural interventions poses complex methodological challenges. The evaluation of our interventions relies primarily on cross-sectional surveys (interviews and HIV testing) of samples of IDUs selected using a combination of targeted cluster and snowball methods. We consider this to be an appropriate, albeit imperfect, design given the study context. This paper presents analyses of data from the IDU surveys conducted just prior to implementation of the interventions and 24 months thereafter. The cross-border interventions have reached large proportions of the IDUs in the project sites, drug-related HIV risk behaviors have declined in frequency, and HIV prevalence among IDUs has been stable in China and declined in Vietnam over the 24 months since the interventions were implemented. Attribution of these positive trends to the interventions must be qualified in light of possible sampling biases and the absence of control groups. However, we believe that the structural interventions implemented by the cross-border project have played a role in stabilizing HIV prevalence among IDUs two years after they were initiated. Evidence of further diffusion of the interventions among IDUs and continued stability or decline of HIV prevalence would strengthen this case.

Adult↗
PubMed2006

Short-term effect of a cultural adaptation of voluntary counseling and testing among female sex workers in China: a quasi-experimental trial.

This study evaluates the efficacy of cultural adaptation of a voluntary counseling and testing (VCT) intervention, in increasing condom use and decreasing rates of sexually transmitted diseases (STDs) among a group of female sex workers (FSWs) in Guangxi, China. This intervention is modeled after the "state-of-the-science" VCT program that was developed and evaluated by the Center for Disease Control and Prevention's Project RESPECT. Four hundred FSWs were assigned to either an intervention group receiving the VCT intervention or a control group receiving standard of care STD testing and treatment. Data were collected at baseline and 6 months postintervention. Outcome measures included HIV/STD related knowledge and perceptions, condom use, and history of STDs. Five common STDs were screened and tested through clinical examination and laboratory testing to serve as biomarkers. After controlling for potential confounders and baseline differences, the VCT intervention group was significantly higher than the control group in HIV/STD related knowledge (p < .0001) and consistent condom use with clients (odds ration [OR] = 2.23; 95% confidence interval [CI] = 1.26-3.96) at 6 months follow-up. In addition, the intervention group had a significantly lower infection rate of STDs than the control group at follow-up (OR = 0.44; 95% CI = 0.24-0.80). This quasi-experimental trial provides evidence that the brief VCT intervention, through appropriate cultural adaptation, can be efficacious in increasing condom use and reducing STD infection rate among FSWs in China.

Adult↗
PubMed2006

Cellular magnetic resonance imaging: current status and future prospects.

Cellular magnetic resonance imaging (CMRI) allows for the tracking of the temporal and spatial migration of cells labeled with MR contrast agents within organs and tissues. This rapidly growing area of experimental research has the potential of translating from bench to bedside and may be used in conjunction with cellular therapy clinical trials or in the evaluation of novel drug therapies. Ex vivo labeling of nonphagocytic cells with superparamagnetic iron oxide nanoparticles or paramagnetic contrast agents (i.e., gadolinium or manganese) allows for the detection of single cells or clusters of labeled cells within target tissues using CMRI following either direct implantation or intravenous injection. However, prior to the translation of experimental cell labeling studies to clinical trials, it is essential to perform preclinical evaluation to demonstrate a lack of toxicity, the ability to scale-up labeling using good manufacturing practice and the ability to detect cells by in vivo MRI in relevant model systems.

Animals↗
PubMed2006

Prospective memory performance across adolescence.

In the present study, the authors explored age differences in event-based prospective memory (PM) across adolescence. The tasks consisted of an ongoing task (OT; i.e., personality questionnaire items, math problems) and an embedded prospective task that required participants to remember to make a special response whenever they encountered a PM cue (i.e., a negative word in the OT). The 341 participants (aged 13-22 years) revealed a significant main effect of age, which indicated better PM performance of young adults compared with teenagers. Moreover, when emphasizing the OT versus the PM task, teenagers' PM profited from PM emphasis more than did young adults' PM. The authors discuss the data in the context of limited executive capacity as a factor influencing cognitive development across adolescence.

Adolescent↗
PubMed2006

A note on time-frequency analysis of finger tapping.

Finger tapping involves 3 important features: time, spatial amplitude, and frequency. In classical analysis, investigators examine timing parameters; in spectral analysis, they examine frequency parameters. Both types of analysis are based on stationary tap information. The authors propose that time-frequency analysis is a useful tool for analyzing nonstationary finger tapping. They describe the method and give examples of frequency modulation, age difference, and speed transition that demonstrate additional insights one can gain by using this analysis.

Biomechanical Phenomena↗
PubMed2006

Francisella tularensis in rodents, China.

A total of 420 rodents in China were examined for Francisella tularensis by polymerase chain reaction. The infection rates were 4.76% in total, and 11.65%, 10.00%, 6.56%, 1.77%, and 0% in Jilin, Xinjiang, Heilongjiang, Inner Mongolia, and Zhejiang, respectively. Sequence analysis showed that all the detected agents belonged to F. tularensis subsp. holarctica.

Animals↗
PubMed2006

[Primary study on proteomics about Ganoderma lucidium spores promoting survival and axon regeneration of injured spinal motor neurons in rats].

OBJECTIVE: To detect some proteins associated with the effect of ganoderma lucidium spores (GASP) on promoting the survival and axon regeneration of injured spinal motor neurons in rats. METHODS: The rats were divided into normal control group, untreated group and GASP-treated group, and the rats in the last two groups received ventral root avulsion. GASP preparation was fed to the rats in the GASP-treated group for 14 days. The gray matter tissues of the lumbar spinal were sampled from rats in each group after 14 days following ventral root avulsion, and the extracted proteins from these tissues were detected by using 2-dimensional electrophoresis. Matrix assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS) was utilized to identify the differentially expressed proteins among these three groups. RESULTS: There were six kinds of proteins differentially expressed among the three groups, which were collapsin response mediator protein 2 (CRMP-2), F-actin capping protein beta subunit (FCP-beta), isocitrate dehydrogenase [NAD] subunit beta (IDH-beta), ATPase, glutamate oxaloacetate transaminase-1 (GOT1) and M2 pyruvate kinase (M2-PK). The expression levels of CRMP-2, IDH-beta, ATPase and GOT1 were higher in the GASP-treated group than those in the untreated group, while the expression levels of FCP-beta and M2-PK were lower than those in the untreated group. CONCLUSION: GASP maybe promotes the survival and axon regeneration of injured spinal motor neurons in rats by virtue of up- or down-regulating the expression levels of the proteins mentioned above.

Actin Capping Proteins↗
PubMed2006

[Expression of CD25+ lymphocytes in nasopharyngeal carcinoma and its association with EBV infection].

OBJECTIVE: To investigate the expression of CD25(+) lymphocytes in nasopharyngeal carcinoma (NPC) tissue and the influence of Epstein-Barr virus (EBV) infection on CD25 expression. METHODS: Immunohistochemistry was used to detect CD25 expression in the NPC tissues and in situ hybridization employed to detect EBV infection with chronic nasopharyngitis tissue as the control sample. RESULTS: Significant difference was noted in the expression of CD25(+) lymphocytes between NPC and chronic inflammatory tissues. The expression was higher in undifferentiated NPC than in keratinizing squamous cell carcinoma and non-keratinizing carcinomas. The NPC tissue was all EBV-positive except for one sample, which was identified as keratinizing carcinoma, but the control samples were all negative for EBV infection, which was correlated with CD25 expression. CONCLUSION: The expression of CD25(+) lymphocytes is higher in NPC tissues and correlated to EBV infection.

Carcinoma, Squamous Cell↗
PubMed2006

[Study on appraisement and determination GHB levels in hair].

OBJECTIVE: The possibility for the identification of GHB administration through hair analysis was investigated to provide method and information for toxicology examination of GHB. METHODS A GC/MS assay for GHB in hair was developed. Endogenous levels of GHB in hair, time course of GHB in hair, relationship between GHB levels in hair and hair color or administration dose were also established by guinea pig model. RESULTS: Endogenous levels of GHB in guinea pig black hair and human black hair were (3.01 +/- 1.41) ng/mg (n=28) and (1.02 +/- 0.27) ng/mg (n=20), respectively. GHB levels in black hair were increased by GHB administration and related with drug dosage, and also much higher than in brown and white hair. CONCLUSION: Analysis of GHB in hair is suitable for investigation of GHB abuse in forensic toxicology and GHB level in segmental analysis compared with endogenous level of GHB may provide useful information about GHB administration.

Animals↗
PubMed2006

[Study on determination and distribution of GHB in biological fluids and tissues of acute poisoned rats].

OBJECTIVE: e To investigate the distribution of GHB in biological fluids and tissues and provide methodand information for detcetion of GHB in Biological Fluids and Tissues METHOD The concentrations of GHB in Biological Fluids and Tissues were analyzed by gas chromatography-mass spectrometry; Two groups of rats were fed with 1000 mg/kg of GHB and were killed at 1 hour and 3 hours post dose, respectively. RESULTS GHB concentrations of the administrated groups distributed in a degressive order of urine, stomach, blood, intestine, kidney, lung, spleen, heart, liver and brain. CONCLUSION: Urine was the best specimen for the determination of GHB concentrations in biological fluids and tissues.

Acute Disease↗
PubMed2006

[Diagnosis of Takayasu's arteritis affecting carotid arteries with multi-slice spiral CT].

OBJECTIVE: To explore changes in the carotid arteries in Tarkayasu arteritis (TA) with computed tomographic angiography (CTA). METHODS: The common carotid artery intima-medial thickness (CCA-IMT) in 20 common carotid arteries (CCAs) in 10 controls and 40 CCAs in 20 patients with TA were analyzed and compared. RESULTS: Contrast-enhanced CT scanning combined with the application of 3D reconstruction clearly showed the carotid vascular luminal abnormalities, such as stenosis, occlusion, dilation, and aneurysm formation. CCA-IMT increased in all the patients with TA affecting carotid arteries. CCA-IMT was significantly larger in the patients than in controls [(0.36 +/- 0.13) cm vs. (0.03 +/- 0.02) cm, P < 0.05] , and was significantly larger in patients with active diseases than in those without active diseases [(0.44 +/- 0.09) cm vs. (0.24 +/- 0.10) cm, P < 0.05]. CONCLUSION: CCA-IMT increases in TA affecting carotid arteries, especially in active diseases.

Adolescent↗
PubMed2006

[Perfusion characteristics of normal pancreas and insulinoma on multi-slice spiral CT].

OBJECTIVE: To investigate the perfusion characteristics of normal pancreas and insulinoma on multi-slice spiral CT (MSCT). METHODS: Totally 21 subjects with suspected insulinoma were enrolled. Sixteen-slice spiral CT was used for perfusion scan following a standard contrast-enhanced scan. The surgical and pathological outcomes were collected for comparison. Perfusion characteristics, including blood flow (BF), patlak blood volume (pBV), time to peak (TTP), permeability, and peak enhancement (PE) of insulinomas and normal pancreas parenchyma were analyzed based on the MSCT data sets subsequently. RESULTS: Benign insulinoma was pathologically confirmed in 12 out of the 21 subjects, while the remaining 9 subjects were normal. Technical failures were experienced in 2 (9.5%) subjects. In both normal and tumor-suffered subjects (n = 19), perfusion parameters of normal pancreatic parachyma were measured as follows: BF (p) = 104. 9 +/- 28.9, pBV (p) = 166.4 +/- 41.8, TrP (p) = 133.3 +/- 24.4, Permeability (p) = 81.3 +/- 24.4, and peak enhancement (p) = 121.3 +/- 31.1. In subjects with insulinoma (n = 11), perfusion parameters of tumor tissue were measured as follows: F (i) = 206.5 +/- 42.2, BV (i) = 315.9 +/- 79.0, TFP (i) = 123.2 +/- 18.8, Permeability (i) = 102.5 +/- 54. 8, and peak enhancement (i) = 221.3 +/- 48.5. Results of F, BV, and peak enhancement in these two kinds of tissue showed significant differences (P < 0.01), while there were no significant difference (P > 0.05) in TTP and permeability between normal pancreatic parenchyma and insulinoma. CONCLUSIONS: Benign insulinoma has perfusion characteristics of increased blood flow and blood volume, but its TTP is consistent with normal pancreas and has normal permeability. MSCT allows further understanding of the blood flow of the normal pancreas and its benign tumor insulinoma.

Adult↗
PubMed2006

[Clinical observation on treatment of rheumatoid arthritis with biqi capsule].

OBJECTIVE: To study the indication and clinical efficacy of Biqi capsule (BC) in treating patients with rheumatoid arthritis (RA). METHODS: One hundred and forty-two RA patients were randomly divided into the BC treated group and the control group treated with nimesulide tablet (NT). There were 36 patients with dampness-heat blockage syndrome type and 35 patients with Qi deficiency and blood stasis syndrome type in each group. The treatment course lasted for 8 weeks. RESULTS: The total effective rate in the BC group was 66.2% (47 cases), while that in the control group was 60.6% (43 cases). The total effective rate in the patients with Qi deficiency and blood stasis syndrome type in the BC group was 91.4%, superior to that with dampness-heat blockage type (41.7%). Only one patient showed mild adverse reaction in the BC group. CONCLUSION: BC is a kind of safe and effective herble medicine for treatment of RA, especially for those of Qi deficiency and blood stasis syndrome type.

Adult↗
PubMed2006

[Effects of GM-CSF on the proliferation and activation of dendritic cells in vivo].

OBJECTIVE: To explore the effects of granulocyte macrophage-colony-stimulating factor (GM-CSF) on the proliferation and activation of dendritic cells (DC) in vivo. METHODS: Balb/c mice were randomly assigned into the control and GM-CSF treatment group. After the lethal dosage of irridiation, green fluorescence protein labelled hematopoietic stem cells (HSC) were injected into the tail veins of the mice. The dosage of 0.1 micorg GM-CSF was administer subcutaneously every 2 days after the HSC infusion. The numbers and activation status of splenic DC were observed by flow cytometry 1, 2, 3, and 4 weeks after the HSC transplantation. RESULTS: The numbers of splenic DC in the GM-CSF treatment group were significantly higher than those of the control group. The expressions of surface marker CD40, CD80, and CD86 in the GM-CSF treatment group were also higher than those of the control group. CONCLUSION: GM-CSF can enhance the proliferation and activation of DC in vivo.

Animals↗
PubMed2006

[Clinical study on keloid treatment with intralesional injection of low concentration 5-fluorouracil].

OBJECTIVE: To explore the effect of intralesional injection of low concentration 5-fluorouracil (5-FU) on inhibition of angiogenesis of keloid. METHODS: 35 patients with 51 keloids were treated with intralesional injection of 5-FU (2-5 mg/ml) biweekly. After 3-6 times of injection, the keloids were treated with intralesional injection of corticosteroid. The average period of treatment was 10.29 months. RESULTS: The efficacy of inhibiting keloid angiogenesis by low concentration of 5-fluorouracil was 96.77%. For the patients who were treated over 6 months with both 5-FU and corticosteroid, the total efficacy was 97.14%. Among them, 45.71% of keloids achieved complete remission, 48.57% mostly remission, 2.86% partial remission and 2.86% no remission. CONCLUSION: Inhibition of keloid angiogenesis with intralesional injection of low concentration of 5-fluorouracil along with corticosteroid injection can achieve satisfactory result.

Adrenal Cortex Hormones↗