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Jie Li

Publications and source records attributed to Jie Li.

At least 163 records · Page 9Linked to original sources
PubMed2005

Anti-apoptosis effects of oxymatrine protect the liver from warm ischemia reperfusion injury in rats.

Warm ischemia and reperfusion (WI/R) results in the release of destructive proinflammatory cytokines and oxygen free radicals, which in turn cause injury to the liver. Apoptosis is regarded as the central mechanism of liver injury during WI/R. Oxymatrine, an extract from a traditional Chinese herb, Sophora flavescens Ait, has been widely used for the treatment of chronic hepatitis, by virtue of its anti-inflammatory and anti-apoptotic activity. The objective of this study was to investigate whether administration of oxymatrine could protect livers against WI/R. The experimental design consisted of three groups of rats (each group contained 10 Wistar rats): one group were treated by sham-operation; the second (control) group with WI/R were administrated saline, and the third group, rats with WI/R, were administered oxymatrine). Oxymatrine was intravenously administered before a 30-minute period of ischemia. Blood samples were collected for biochemical assay. Liver samples taken at different time points underwent histological examination for detection of apoptotic cells, and Western blotting analysis for Fas and Fas ligand, the key factors in the upper apoptotic pathways. Histologic alteration of the liver was attenuated in oxymatrine-treated rats, and the serum levels of AST and ALT were significantly (P < 0.01) reduced (73% and 61%, respectively). Oxymatrine significantly inhibited cell apoptosis, as examined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), and it reduced the apoptotic index by 65% (P < 0.05%) as detected by flow cytometry. The anti-apoptotic activity of oxymatrine depends mainly on downregulation of Fas and Fas ligand. The results of this study indicate that oxymatrine may represent a potent drug to protect the liver against WI/R injury.

Alkaloids↗
PubMed2005

Effect of metallothionein on cell viability and its interactions with cadmium and zinc in HEK293 cells.

Metallothioneins (MTs) are thought to participate in a wide variety of physiological roles, but the mechanisms involved are still unclear. The study was designed to examine the possible factors related to these mechanisms. Methods, including transfection, MTT assay and flow cytometry, were used to investigate the effect of MTs on cell viability and their interactions with cadmium and zinc in HEK293 cells. The results showed that transient overexpression of human MT1A, MT2 and MT3 genes dynamically affected cell viability, and the effect was influenced by zinc and cadmium ions. Overexpressed MTs with added zinc showed a greater inhibitory effect on cell viability. Overexpressed MTs protected cells against low concentrations of cadmium ions (10 microM), but increased cell death in response to high concentrations (20-50 microM). Out of the three MTs, MT1A was more efficient than MT2 and MT3 in its resistance to cadmium (10 microM), and MT3 together with zinc showed more cell growth inhibition than MT1 and MT2. These results indicate that both of the divalent metal ions that could bind MTs, as well as the individual MT isoforms, affect the role of MTs on cell viability, which may explain in part why the comprehensive effect of MTs on the cells was elusive.

Blotting, Western↗
PubMed2005

Plasmodium falciparum serine-repeat antigen (SERA) forms a homodimer through disulfide bond.

Plasmodium falciparum serine-repeat antigen (SERA) is one potential blood-stage vaccine candidate and is expressed as a protomer that is subsequently processed into four fragments (P47, P50, P6, and P17). Although recent evidence shows that P50 exhibits chymotrypsin-like protease activity, the function of SERA is still largely unknown. Here, we found that apart from cathepsin L-like cysteine protease, P50 showed significant homology to silicatein-alpha and testin which were shown to bind to cellular components, suggesting that SERA may have similar function. Immunoprecipitation of schizont lysate and molecular assignment of its precipitate by mass spectrometry provided evidence that SERA forms a homodimer through disulfide bond. Moreover, analysis of the fate of SERA using cell-free system revealed that the kinetics of conversion of SERA dimer into monomer is faster than that of processing of SERA monomer into various fragments. These findings may contribute to elucidate a possible function of SERA other than a protease.

Amino Acid Sequence↗
PubMed2005

Grey-scale contrast enhancement in rabbit liver with SonoVue at different doses.

To evaluate the dose of ultrasound (US) contrast agent (UCA) in relation to the contrast-enhancement effect, an in vivo model of perfusion was studied using SonoVue, a second-generation UCA, and low mechanical index (MI) grey-scale harmonic imaging. SonoVue, at eight different doses (0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14 and 0.16 mL/kg BW), was applied in five normal rabbits. Flow-related parameters obtained from time-intensity curves were calculated and plotted over the contrast agent doses, and nonlinear curve fitting was performed. Results showed that, along with an increase of the administrated contrast agent dose, the enhancement duration (ED) and the area under the curve (AUC) increased logarithmically, and the time to enhancement (ET) decreased logarithmically. There was a progressive increase of the peak signal intensity (PSI) following an increase of SonoVue dose only in the dose range of 0.02 up to 0.10 mL/kg body weight (BW) in the portal vein and in the dose range of 0.02 up to 0.12 mL/kg BW in the liver parenchyma. Moreover, a good correlation was observed between the parameters obtained from liver parenchyma and those obtained from the portal vein. The results indicated that SonoVue in conjunction with continuous harmonic low-MI grey-scale imaging has the capability of flow quantification on both vessels and parenchyma. The parameters of time-intensity curve were influenced intensely by different contrast agent doses.

Animals↗
PubMed2005

Mode of action of lactocin 160, a bacteriocin from vaginal Lactobacillus rhamnosus.

OBJECTIVES: To determine the mechanism of antimicrobial action of lactocin 160, a bacteriocin produced by the healthy vaginal strain of Lactobacillus rhamnosus, using an established model, with Micrococcus luteus ATCC 10420 as a test organism. METHODS: Sensitivity of M. luteus to lactocin 160 was determined by the diffusion assay. Loss of cellular ATP in the lactocin-treated cells was elucidated using a commercially available ATP determination kit (luciferin-luciferase bioluminescence assay). Luminescence intensity as a reflection of ATP quantity was determined using a luminometer. Dissipation of membrane potential (Deltapsi) was studied using fluorophore DiSC3(5) with the fluorescence spectrum sensitive to changes in Deltapsi. RESULTS: Lactocin 160 inhibited growth of M. luteus ATCC 10420 at a concentration of 5 microg/ml. There were no significant changes in the intracellular ATP level of M. luteus upon the addition of 20 microg/ml of lactocin 160. However, the extracellular ATP level increased significantly. This means that the treatment of cells with lactocin 160 resulted in an efflux of ATP from inside the cells. Therefore, a partially purified lactocin 160 preparation (16 microg /ml of the bacteriocin in the sample) killed sensitive cells and dissipated 3.12 +/- 0.36% of Deltapsi. CONCLUSION: Lactocin 160 has a mode of action typical for bacteriocins. It disturbs the cellular membrane (Deltapsi dissipation) and induces ATP efflux, most likely because of the pore formation, which is a common mechanism of action for many bacteriocins.

Adenosine Triphosphate↗
PubMed2005

Impaired proteasome activity and accumulation of ubiquitinated substrates in a hereditary neuropathy model.

Accumulation of misfolded proteins and alterations in the ubiquitin-proteasome pathway are associated with various neurodegenerative conditions of the CNS and PNS. Aggregates containing ubiquitin and peripheral myelin protein 22 (PMP22) have been observed in the Trembler J mouse model of Charcot-Marie-Tooth disease type 1A demyelinating neuropathy. In these nerves, the turnover rate of the newly synthesized PMP22 is reduced, suggesting proteasome impairment. Here we show evidence of proteasome impairment in Trembler J neuropathy samples compared with wild-type, as measured by reduced degradation of substrate reporters. Proteasome impairment correlates with increased levels of polyubiquitinated proteins, including PMP22, and the recruitment of E1, 20S and 11S to aggresomes formed either spontaneously due to the Trembler J mutation or upon proteasome inhibition. Furthermore, myelin basic protein, an endogenous Schwann cell proteasome substrate, associates with PMP22 aggregates in affected nerves. Together, our data show that in neuropathy nerves, reduced proteasome activity is coupled with the accumulation of ubiquitinated substrates, and the recruitment of proteasomal pathway constituents to aggregates. These results provide novel insights into the mechanism by which altered degradation of Schwann cell proteins may contribute to the pathogenesis of certain PMP22 neuropathies.

Animals↗
PubMed2005

Induction of invasive mouse skin carcinomas in transgenic mice with mutations in both H-ras and p53.

Synergistic interaction between H-ras and p53 were systematically examined during skin tumorigenesis. Concurrent expression of an activated H-ras gene and a mutant p53 gene was accomplished by crossing p53(Val135/wt) mice with TG.AC mice. Topical application to wild-type mice with benzo(a)pyrene (BaP) alone produced approximately 26% skin tumor incidence, whereas BaP treatment of p53(wt/wt)Hras(TG.AC/wt), p53(Val135/wt)Hras(wt/wt), and p53(Val135/wt)Hras(TG.AC/wt) mice produced a 75%, 77%, and 100% incidence of skin tumors, respectively. An average of 0.33 tumor per mouse was observed in wild-type (p53(wt/wt)Hras(wt/wt)) mice, whereas approximately 1.54, 1.96, and 3.08 tumors per mouse were seen in BaP-treated p53(wt/wt)Hras(TG.AC/wt), p53(Val135/wt)Hras(wt/wt), and p53(Val135/wt)Hras(TG.AC/wt) mice, respectively. The effects on total tumor volume were even more striking with 7-, 48-, and 588-fold increases in tumor volume compared with wild-type (p53(wt/wt)Hras(wt/wt)) in p53(wt/wt)Hras(TG.AC/wt), p53(Val135/wt)Hras(wt/wt), and p53(Val135/wt)Hras(TG.AC/wt) mice, respectively. Histopathologically, all tumors from p53(wt/wt)Hras(wt/wt) mice were either papillomas or well-differentiated squamous cell carcinomas, whereas the tumors in p53(wt/wt)Hras(TG.AC/wt), p53(Val135/wt)Hras(wt/wt), and p53(Val135/wt)Hras(TG.AC/wt) mice were principally squamous cell carcinomas with varying degree of invasiveness. Particularly, tumors in p53(Val135/wt)Hras(TG.AC/wt) mice exhibited the most rapid growth and the extreme form of tumor invasion. Microarray analysis revealed that dominant-negative p53 (Val135) and activated H-ras affected several cellular processes involved in tumorigenesis possibly through its effects on apoptosis, cell cycle arrest, and Ras-mitogen-activated protein kinase pathways. The present study provides the first in vivo evidence that a germ line p53 mutation and activated H-ras act synergistically to profoundly enhance tumor progression.

Animals↗
PubMed2005

Delivering distance training to rural health care professionals.

This article reports on a project that delivers distance training to rural health care professionals. Traveling to provide training on information-seeking skills to rural health professionals is time consuming and costly. In addition to face-to-face training, the University of South Alabama Biomedical Library's SAMNet project seeks to deliver multimedia training to rural health care professionals. The project uses information technology to package training courses combining PowerPoint slides and video instructions. This article describes the rationale, training module design and development, and the information technology and software used in the project. Multimedia packaged distance training courses provide a practical alternative to on-site training for rural health care professionals. It enables librarians to provide training without traveling long distance, thus saving time and money. Additionally, rural health care professionals may access the modules at a time convenient to them and proceed at a pace suitable to their learning style.

Academic Medical Centers↗
PubMed2005

Time-intensity-based quantification of vascularity with single-level dynamic contrast-enhanced ultrasonography: a pilot animal study.

OBJECTIVE: The purpose of this study was to delineate the hemodynamic features of VX2 tumor and perineoplastic liver parenchyma and to evaluate the potential usefulness of single-level dynamic ultrasonography in the diagnosis of tumors by the analysis of time-intensity curves. METHODS: An in vivo animal model was studied using a low mechanical index in conjunction with single-level dynamic contrast-enhanced ultrasonography. A sulfur hexafluoride contrast agent (SonoVue; Bracco SpA, Milan, Italy) was applied in 8 rabbits by intravenous bolus injection. Data were acquired before and after VX2 tumor induction. Corresponding parameters of the time-intensity curve were measured using wash-in/wash-out curve software. RESULTS: No significant difference was found in the time to enhancement, time to peak intensity, peak signal intensity, and enhancement duration between liver parenchyma before and after VX2 tumor induction (P > .05). The typical enhancement pattern of VX2 tumors was hyperechoic relative to liver parenchyma during the early phase and hypoechoic during the later phase. The curves obtained in carcinomas revealed an early arrival time and time to peak intensity with an irregular and sharp decrease of the intensity signal and a very early return to baseline, presenting a much more rapid wash-in and wash-out of ultrasonographic contrast agents. There was a significant difference in the time to enhancement, time to peak intensity, peak signal intensity, and enhancement duration between the VX2 tumors and perineoplastic liver parenchyma (P < .001). CONCLUSIONS: Single-level dynamic contrast-enhanced ultrasonography with a low mechanical index level could provide real-time and continuous enhanced images and fully delineate the typical enhancement pattern of liver tumors. The analysis of time-intensity curves may provide useful, complementary, and quantitative information. This technique may be useful for the diagnosis of liver tumors, especially those showing an atypical enhancement pattern on biphasic helical computed tomographic scanning.

Animals↗
PubMed2005

[Expression of soluble human leukocyte antigen G and its relationship to embryo development].

OBJECTIVE: To find out the expression of soluble human leukocyte antigen G (sHLA-G) and its relationship to the cleavage embryo development. METHODS: One hundred and seventy-seven day 3 cleavage embryos were detected for sHLA-G by immunohistochemistry. RESULTS: sHLA-G was detected in 57.1% cleavage embryos. The positive rate of sHLA-G in cleavage embryos developed from dipronucleate fertilized eggs was 66.2% (90/136), that developed from tripronucleate fertilized eggs was 26.8% (11/41). There was significant difference between these two groups (P < 0.01). The positive rate of sHLA-G in the grade 1 cleavage embryos developed from dipronucleate fertilized eggs was 64.3% (18/28), that in the grade 2 cleavage embryos developed from dipronucleate fertilized eggs was 91.7% (66/72), that in the grade 3 cleavage embryos developed from dipronucleate fertilized eggs was 16.7% (6/36), there were significant differences between these different embryo grades (P < 0.01), and the intensity of sHLA-G had negative relationship with the embryo grades (r = -0.503). The positive rate of sHLA-G in the first class cleavage embryos developed from tripronucleate fertilized eggs was 88.9% (32/36), that from dipronucleate fertilized eggs was 64.3% (18/28). There was significant difference in these two groups (P < 0.01). The intensity of sHLA-G in cleavage embryos developed from tripronucleate fertilized eggs was higher than that from dipronucleate fertilized eggs. The positive rate of sHLA-G in the cleavage embryos developed from dipronucleate fertilized eggs whose cell number was less than 4 was 56.7% (34/60), that from dipronucleate fertilized eggs whose cell number ranged from 5 to 6 was 67.9% (36/53), and that from dipronucleate fertilized eggs whose cell number ranged from 7 to 8 was 87.0% (20/23). There were no significant differences in these three groups. The intensity of sHLA-G had no significant difference between embryos with different cell number (P > 0.05), but it had relationship with the cell number (r = 0.267). CONCLUSION: Cleavage embryos express sHLA-G which is related with the embryo development.

Adult↗
PubMed2005

[Application of depth-analysis of confocal Raman micro-spectroscopy to chirography identification].

Depth analysis of confocal Raman micro-spectroscopy was applied to chirography identification. The result indicated that depth analysis has potential application to forensic science field, especially in longitudinal identification of ink and inkpad. No matter what the spatial distributions of the signature pen and inkpad are, confocal Raman micro-spectroscopy can longitudinally distinguish those spatial differences. All those suggested that confocal Raman micro-spectroscopy is a fast, simple, high sensitive and non-destructive technique.

Forensic Medicine↗
PubMed2005

[Emission spectra of hydroxyl radical generated in air corona discharge].

In this paper, the relative emission intensity of the 309 nm transition band of hydroxyl radical (OH) was measured by a CCD imaging spectrometer in a pin-plane corona discharge scheme of one atmosphere pressure air injected with unsaturated water vapor from the central hole of the used pins. The influences of several factors on the OH radical production were investigated by relative emission intensity measurement. The production of OH radical increased with a limited increment of water vapor concentration in the mixed gas. Compared with positive DC corona discharges, more OH radicals were generated in positive pulsed corona discharges and less in negative DC corona discharges. The spatial distribution of OH radical production was also observed. Most OH radicals were produced within the range of 5 mm off the discharge pin electrode. In conclusion, this means of optical emission spectroscopy, compared with more sophisticated laser fluorescence measurements used for plasma OH production diagnostics investigation, is simpler and more effective for characterizing the OH radical potential for pollutant oxidation.

Air↗
PubMed2005

[Effects of ketamine and midazolam combination anesthesia on focal cerebral ischemia injury in rats].

OBJECTIVE: We investigated the effects of anesthesia with ketamine and midazolam on focal cerebral ischemia injury, and evaluated the neuroprotective properties of this combination during surgical procedures. METHODS: Thirty male Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO) under ketamine or ketamine-midazolam intraperitoneal anesthesia (n = 15 each). The neurological scoring was performed to determine functional impairment of the brain at 4 h after MCAO. TTC staining of brain slices was used to measure infarct size of the brain at 24 h after MCAO. At day 3 after MCAO, TUNEL staining was employed to detect apoptotic cells in the penumbra. RESULTS: Although neurological scoring (1.57 +/- 0.65 vs 1.74 +/- 0.52) was not significantly different between ketamine and ketamine-midazolam groups (P > 0.05), infarct size and apoptotic cell density in the penumbra were significantly lower in the ketamine-midazolaml group than those in the ketaminel group [infarct size: (24.1 +/- 4.63)% vs (38.48 +/- 4.18)%; apoptotic cells density: (178 +/- 23) cells/mm2 vs (258 +/- 15) cells/mm2, P < 0.05], respectively. CONCLUSION: The above findings suggested that ketamine and midazolam combination might provide neuroprotection during surgical procedures that pose risk for ischemic cerebral injury.

Anesthesia↗
PubMed2005

[Antimicrobial resistance of Gram-negative bacilli isolated from patients in intensive care unit].

OBJECTIVE: To evaluate antimicrobial resistance of Gram-negative bacilli isolated from patients in intensive care unit (ICU) and to provide guidance for clinical antimicrobial strategy. METHODS: Antimicrobial susceptibility of Gram-negative bacilli isolated from patients in ICU from 2000 to 2003 was monitored by Epsilometer test E (E-test) methods, and at the same time Whonet 5.1 was used to analyse the results. RESULTS: Imipenem had the highest antimicrobial efficiency rate(90.8%), followed by cefoperazone/sulbactam, piperacillin/tazobactam, cefepime, amikacin and ceftazidime. On the other hand, the efficiency rate of the third-generation cephalosporins such as cefotaxime and ceftriaxone was as low as 42.8%. The extended-spectrum beta-lactamases (ESBLs) producing strains accounted for 36.0% in E.coli and 25.0% in K. pneumoniae. Significant difference was found between the resistant rate of ESBLs positive and that of negative strains, except imipenem (all P<0.005). CONCLUSION: Bacterial resistance against antibiotics is still a serious clinical problem among ICU patients, therefore, surveillance of antimicrobial resistance should be strengthened, and the use of the third-generation cephalosporins should be restricted.

Drug Resistance, Bacterial↗
PubMed2005

Closely linked polymorphic marker: successful application in preimplantation genetic diagnosis for beta-thalassemia.

OBJECTIVE: To evaluate the applicability of the polymorphic marker closely linked with beta-globin gene for the preimplantation genetic diagnosis (PGD) in couples at risk of having child with beta-thalassemia. METHODS: Single cell multiplex nested PCR which coamplifies the beta-globin gene and the closely linked polymorphic marker, HumTHO1 gene, was applied in six clinical PGD cycles for four couples with beta-thalassemia. RESULTS: In six clinical PGD cycles, a total of 44 embryos were biopsied and 44 blastomeres were obtained. Forty-one blastomeres were amplified and thirty-five embryos were given definite diagnoses. Fourteen embryos were transferred back to the uterus of the patients and one pregnancy went on well and ended with one live healthy birth, which confirmed the results of PGD. The average amplification efficiency of single blastomere was 89.7% and the average allele drop-out(ADO) rate was 14.4%. The coamplification of HumTHO1 could help to detect the existence of ADO and contamination. CONCLUSION: This is the first report on unaffected pregnancy resulting from PGD using multiplex nested PCR in China. The simultaneous amplification of polymorphic marker closely linked to beta-globin gene(HumTHO1) could help to resist the risk of misdiagnosis in PGD caused by ADO and contamination.

Adult↗
PubMed2005

[Research on gene expression data based on clustering/classification technology].

As the work of sequencing the genome of the human and many model organisms has been partially or fully finished, the "postgenomic era" has begun. Scientists are turning their focus toward identifying gene function from sequencing. Clustering technology, as one of the important tools of analyzing gene expression data and identifying gene function, has been used widely. In this paper we discuss main clustering technology about gene expression data at present, analyze their advantages and disadvantages, present the methods to solve the problems and give new approaches to study gene expression data.

Algorithms↗