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Biomedical subjects

Ming Li

Publications and source records attributed to Ming Li.

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

[Study of antmicrobial mechanisms of human cervical mucus: isolation and characterization of antibacterial polypeptides].

OBJECTIVE: To isolate and purify antibacterial polypeptides from human cervical mucus. METHODS: Human cervical mucus was collected from human healthy subjects and acid-soluble extract was obtained by solving the mucus with 5% acetic acid in the presence of protease inhibitors. The antibacterial components were identified by Agar radial diffusion assay and gel overlay technique. For further purification, Preparative acid-urea gel electrophoresis and Reverse Phase HPLC were performed. The N-terminal sequencing and degenerate PCR-directered cDNA cloning were performed. The E. coli-based recombinant product was prepared and its antibacterial property was determined by minimal inhibitory concentration and minimal bactericidal concentration. RESULTS: A purified antibacterial polypeptide was obtained. Agar radial diffusion assay showed that the purified polypeptide had antibacterial activities against E. coli ML-35P and Pseudomanas aeruginosa ATCC 27853. The N-terminal amino acid sequence and its full length of cDNA were identical to High Mobility Group Chromosal protein N2 (HMGN2). The purified recombinant HMGN2 was obtained. Its MIC against E. coli ML-35p and P. aeruginosa ATCC27853 were 10.42 microg/ml +/- 3.13 microg/ml and 27.78 microg/ml +/- 8.33 microg/ml respectively, which were equal to human neutrophil defensins HNP, and the MBC were 20.83 microg/ml +/- 6.25 microg/ml and 55.56 microg/ml +/- 16.67 microg/ml respectively. CONCLUSION: HMGN2 may be another antibacterial effecter in the defense mechanisms of human cervical mucus.

Adult↗
PubMed2005

Nuclear survivin predicts recurrence and poor survival in patients with resected nonsmall cell lung carcinoma.

BACKGROUND: Survivin, which is a member of the inhibitor of apoptosis protein gene family, regulates both programmed cell death and mitosis. It has been shown that survivin expression and its subcellular localization both have prognostic value for patients with malignant disease. In this study, the authors investigated whether nuclear or cytoplasmic staining of survivin was a prognostic marker for patients with lung carcinoma. METHODS: Paraffin-embedded tissue blocks from 144 patients with Stage I and II resected nonsmall cell lung carcinoma (NSCLC) were obtained for immunohistochemical staining. Three specimens from each patient were prepared and stained with a survivin-specific antibody. Nuclear and cytoplasmic staining was graded from 1 to 3 based on intensity. RESULTS: Patients who had nuclear staining for survivin had a significantly increased risk of disease recurrence (hazard ratio, 2.95; P = 0.0046) and death (hazard ratio, 2.74; P = 0.0086). CONCLUSIONS: The nuclear presence of survivin may be an independent biomarker for disease recurrence and overall survival in patients with resected Stage I and II NSCLC.

Adult↗
PubMed2005

Arabidopsis tic110 is essential for the assembly and function of the protein import machinery of plastids.

The translocon at the inner envelope membrane of chloroplasts (Tic) plays a central role in plastid biogenesis by coordinating the sorting of nucleus-encoded preproteins across the inner membrane and coordinating the interactions of preproteins with the processing and folding machineries of the stroma. Despite these activities, the precise roles of known Tic proteins in translocation, sorting, and preprotein maturation have not been defined. In this report, we examine the in vivo function of a major Tic component, Tic110. We demonstrate that Arabidopsis thaliana Tic110 (atTic110) is essential for plastid biogenesis and plant viability. The downregulation of atTic110 expression results in the reduced accumulation of a wide variety of plastid proteins. The expression of dominant negative mutants of atTic110 disrupts assembly of Tic complexes and the translocation of preproteins across the inner envelope membrane. Together, these data suggest that Tic110 plays a general role in the import of nuclear-encoded preproteins as a common component of Tic complexes.

Active Transport, Cell Nucleus↗
PubMed2005

[Treatment of the infrequent complications after stent graft placement for aortic disease].

OBJECTIVE: To explore the infrequent complications and treatment after endoluminal stent graft implantation for aortic diseases. METHODS: Review of the characters and complications for five cases of aortic diseases by stent graft implantation. RESULTS: The complications of 4 cases have been relieved by operation or re-stent implantation, 1 case was died. CONCLUSION: The complications are difficult to forecast for stent graft placement in aortic diseases, the surgeon should be well practiced in surgical and interventional technique, so as to treat the complications in time.

Aged↗
PubMed2005

The critical role of Exo84p in the organization and polarized localization of the exocyst complex.

The exocyst complex plays an essential role in tethering secretory vesicles to specific domains of the plasma membrane for exocytosis. However, how the exocyst complex is assembled and targeted to sites of secretion is unclear. Here, we have investigated the role of the exocyst component Exo84p in these processes. We have generated an array of temperature-sensitive yeast exo84 mutants. Electron microscopy and cargo protein traffic analyses of these mutants indicated that Exo84p is specifically involved in the post-Golgi stage of secretion. Using various yeast mutants, we systematically studied the localization of Exo84p and other exocyst proteins by fluorescence microscopy. We found that pre-Golgi traffic and polarized actin organization are required for Exo84p localization. However, none of the exocyst proteins controls Exo84p polarization. In addition, Sec3p is not responsible for the polarization of Exo84p or any other exocyst component to the daughter cell. On the other hand, several exocyst members, including Sec10p, Sec15p, and Exo70p, clearly require Exo84p for their polarization. Biochemical analyses of the exocyst composition indicated that the assembly of Sec10p, Sec15p, and Exo70p with the rest of the complex requires Exo84p. We propose that there are at least two distinct regulatory mechanisms for exocyst polarization, one for Sec3p and one for the other members, including Exo84p. Exo84p plays a critical role in both the assembly of the exocyst and its targeting to sites of secretion.

Cathepsin A↗
PubMed2005

Temperature dependence of interfacial fluctuations of polymerized fatty acid salt multilayers.

X-ray scattering was used to study the temperature dependence of the profile structure of polymerized 10,12-tricosadiynoic acid salt multilayers. The stacking periodicity of the multilayers was found to decrease with increasing temperature due to the conformational changes of the alkyl chains. When the samples were fully hydrated in water, the reflectivity measurement showed that the thermal fluctuations of the interfaces are enhanced with temperature, resulting in reduced ordering. Meanwhile, the diffuse scattering indicated that the thermal fluctuations renormalize the elasticity of the multilayers; both the bending and the compression moduli are reduced. Similar measurements performed in air, however, do not show this thermal enhancement although the stacking periodicity decreases in the same manner. It is implied that water might weaken the interaction between the carboxyl groups and the metal ions so that the polymerized bilayers are softened in water.

Journal Article↗
PubMed2005

[Effects of taurine on early changes of excitatory amino acids in rabbit brain due to deep hypothermic circulatory arrest].

OBJECTIVE: To study the effects of taurine (Tau) on early changes of excitatory amino acids (EAA) in hippocampus rabbit brain due to deep hypothermic circulatory arrest (DHCA). METHODS: Sixteen New Zealand rabbits were randomly allocated into 2 groups: Tau 150 mg/kg group (group I, n = 8), control group (group II, n = 8). Cardiac pulmonary bypass (CPB) was set up after cerebral microdialysis model was established. High performance liquid chromatography was employed to monitor the continuous changes of glutamic acid (Glu), aspartic acid (Asp), Tau and glycine (Gly) in the hippocampus CA1 region at anaesthesia periods, CPB stage, pre 30 minutes in DHCA, post 30 minutes in DHCA, pre 30 minutes in rewarming, post 30 minutes in rewarming. RESULTS: The increase of Glu in group II was (5.1 +/- 1.5) and (4.1 +/- 1.4) times higher than that at anaesthesia periods (t = 3.74, 5.45, P < 0.01), and the increase of Glu in group I was (2.1 +/- 1.5) and (1.1 +/- 0.4) times than that at anaesthesia periods at pre 30 minutes and post 30 minutes rewarming stage respectively. Rising of Gly in group II was 6.7 (3.6, 13.6) times than that at anaesthesia periods (T = 75.00, P < 0.05), the rising of Gly in group I was 4.2 (3.8, 11.5) times at post 30 minutes in DHCA. Rising of Tau in group I was 6.9 (3.0, 14.2) and 10.6 (2.8, 22.5) times than that at anaesthesia periods (T = 75.00, P < 0.05 and T = 90.00, P < 0.05) and rising of Tau in group II was 4.0 (3.0, 5.7) and 3.2 (1.2, 7.6) times than that at anaesthesia periods at post 30 minutes in DHCA and pre 30 minutes rewarming stage respectively. Asp was no evident change at every periods. CONCLUSION: DHCA might increase the excitatory amino acids in the early phases of circulatory restoration. Exterior Tau 150 mg/kg could inhibit release of EAA.

Animals↗
PubMed2005

Crystallization and preliminary X-ray studies of a non-haemorrhagic fibrin(ogen)olytic metalloproteinase from the venom of Agkistrodon acutus.

A non-haemorrhagic fibrin(ogen)olytic metalloproteinase from the venom of Agkistrodon acutus has been crystallized by the hanging-drop method. The crystals belong to space group P3(1)21, with unit-cell parameters a = b = 80.57, c = 66.77 A and one molecule in the asymmetric unit. X-ray diffraction data were collected to 1.86 A resolution.

Agkistrodon↗
PubMed2005

Cross GTPase-activating protein (CrossGAP)/Vilse links the Roundabout receptor to Rac to regulate midline repulsion.

The regulators of the Rho-family GTPases, GTPase-activating proteins (GAPs) and guanine exchange factors (GEFs), play important roles in axon guidance. By means of a functional genomic study of the Rho-family GEFs and GAPs in Drosophila, we have identified a Rho-family GAP, CrossGAP (CrGAP), which is involved in Roundabout (Robo) receptor-mediated repulsive axon guidance. CrGAP physically associates with the Robo receptor. Too much or too little CrGAP activity leads to defects in Robo-mediated repulsion at the midline choice point. The CrGAP gain-of-function phenotype mimics the loss-of-function phenotypes of both Robo and Rac. Dosage-sensitive genetic interactions among CrGAP, Robo, and Rac support a model in which CrGAP transduces signals downstream of Robo receptor to regulate Rac-dependent cytoskeletal changes.

Animals↗
PubMed2005

Prototropic tautomerism of imidazolone in aqueous solution: a density functional approach using the combined discrete/self-consistent reaction field (SCRF) models.

A systematic investigation of the proton transfer in the keto-amino/enol tautomerization of imidazolone was undertaken. Calculations in aqueous solution were performed using both combined discrete/self-consistent reaction field (SCRF) and SCRF methods. Complexes containing one to three water molecules around the hydrophilic site of imidazolone were used for the combined discrete/SCRF calculations. The DFT results predict that the barrier height for non-water-assisted intramolecular proton transfer is very high (214.8 kJmol(-1)). Hydrogen bonding between imidazolone and the water molecule(s) will dramatically lower the barrier by a concerted multiple proton transfer mechanism. The proton transfer process through a eight-member ring formed by imidazolone and two water molecules is found to be more efficient and the calculated barrier height is ca. 61 kJmol(-1).

Hydrogen Bonding↗
PubMed2005

Expression profile of cancer-testis genes in 121 human colorectal cancer tissue and adjacent normal tissue.

PURPOSE: Among tumor antigens identified to date, cancer-testis (CT) antigens, which are coded by CT genes, are identified as a group of highly attractive targets for cancer vaccines. This study is the first to analyze the mRNA expression and possible correlation with pathologic characteristics of multiple CT genes in a large cohort of colorectal cancer (CRC) patients. EXPERIMENTAL DESIGN: The expression of 10 individual CT genes in 121 CRC and adjacent tissues were analyzed by RT-PCR method. The presence of autologous antibodies against NY-ESO-1 was examined in serum samples by ELISA. To confirm the protein expression, immunohistochemistry was done for detecting the NY-ESO-1 antigen in mRNA-positive CRC tissues. RESULTS: The CT genes were detected with various frequencies in CRC tissue, SCP-1, 1.7%; SSX-2, 2.5%; SSX-4, 2.5%; SSX-1, 5.0%; CT10, 6.6%; NY-ESO-1, 9.9%; MAGE-1, 11.6%; LAGE-1, 15.7%; MAGE-4, 22.3%; and MAGE-3, 27.3%. In 56.2% of tumor tissues examined in this study, at least one CT gene was detected. In contrast, no CT gene expression was found in cancer adjacent tissues. Among 10 CT genes investigated, NY-ESO-1 and LAGE-1 are of particular interest because their mRNA expression in CRC was rarely reported before. In our study, NY-ESO-1 mRNA was found to express in 9.9% of the samples, and also correlated significantly with stages (P = 0.041) and local lymph node metastasis (P = 0.002). In addition, we also identified one NY-ESO-1 antibody-positive serum sample. MAGE-4 mRNA was expressed at a high frequency in tumor tissues with vessel emboli samples (P = 0.025). CONCLUSIONS: These results suggested that CT genes, especially NY-ESO-1 and LAGE-1, do express in CRC. More than 50% of the CRC patients in this study express at least one CT gene, making them eligible for CT vaccination. NY-ESO-1 gene may serve as a marker for local metastasis and advanced disease. MAGE-4 gene is significantly associated with the vessel emboli.

Adult↗
PubMed2005

Electrochemical self-assembly of highly oriented ZnO-surfactant hybrid multilayers.

Highly oriented zinc oxide-surfactant hybrid multilayers were electrochemically self-assembled on silicon substrates from Zn(NO3)2 solutions containing extremely low concentration of sodium dodecyl sulfate (SDS). The X-ray diffraction results showed that the structure of the hybrid film is sensitive to the concentration of SDS. When the concentration of SDS is below a critical value, 0.002 wt %, a surfactant bilayer is adsorbed on the silicon surface, together with electrodeposited crystalline ZnO particles. Above this concentration, lamellar ZnO-surfactant hybrid films are formed, the period of which decreases from 31.7 +/- 0.2 A at 0.003 wt % to 27.5 +/- 0.2 A at 0.005 wt %, another critical concentration. It then increases monotonically and reaches its maximum of 33.0 +/- 0.2 A above 0.05 wt %. The results implied that the kinetics of the electrochemical self-assembly depends on the relative speed of the reduction of the zinc ions and the aggregation of the surfactant. The two processes occur cooperatively at the electrolyte-electrode interface to form the hybrid films.

Journal Article↗
PubMed2005

[The efficacy of third-generation instrumentation for the treatment of adult scoliosis].

OBJECTIVE: To evaluate the efficacy of third generation spinal instrumentation such as TSRH, CD and ISOLA for the treatment of adult scoliosis. METHODS: Thirty-five adult scoliosis patients including adult idiopathic and degenerative scoliosis were all surgically treated with third generation instrumentation such as TSRH, CD and ISOLA from July 1999 to January 2003. Preoperative mean cobb angles of major curves of the frontal plane was 58.1 degrees (42 degrees -95 degrees ). The patients received anterior combined with posterior correction or single posterior procedure. Mean follow-up was 20 months (10 - 48 months). Preoperative and postoperative Cobb angles of the frontal plane and sagittal plane and distance between C(7) and CVSL were measured. We assessed the subjective efficacy by questionnaire. RESULTS: Clinical appearance of all patients improved significantly. Mean correction of major curves of the coronal plane was 53.2%. Mean lost of correction of the coronal plane in the last follow-up was 4.3 degrees , distance between the midline of C(7) and CVSL was corrected from 2.6 cm to 0.24 cm. Questionnaire in the follow-up showed that 89.3% patients were satisfied with operation results. Two cases occurred pneumatothorax and haematothorax. Three cases still complained about low back pain in 1 year after operation, among which 2 were adjacent degeneration and 1 was pseudarthrosis. CONCLUSION: Imageology assessment and patients self-evaluation shows that the third generation instrumentation could gain good correction and trunk balance in the treatment for adult scoliosis. And patients are more satisfied and have less complications.

Adult↗
PubMed2005

Clinical significance of matrix metalloproteinase-9 expression in esophageal squamous cell carcinoma.

AIM: To evaluate the expression of matrix metalloproteinase-9 (MMP-9) and its clinical significance in esophageal squamous cell carcinoma (ESCC). METHODS: The expression of MMP-9 in 208 cases of ESCC was detected by immunohistochemistry (IHC) and its clinical significance in ESCC especially the relationship with the clinicopathological parameters was analyzed. RESULTS: The percentage of positive cases for MMP-9 detected by IHC was 49.0%. MMP-9 was mainly expressed in the cytoplasm of cancer cells especially in the invasive front. Only weak expression was detected in the stromal cells and no expression in non-cancerous mucosa. The expression of MMP-9 was positively correlated with poorer differentiation (P = 0.001<0.01), existence of vessel permeation (P = 0.027<0.05) and lymph node metastasis (P = 0.027<0.05). CONCLUSION: The expression of MMP-9 correlates with the cancer cell differentiation, vessel permeation and lymph node metastasis. It may be a novel biomarker for the diagnosis and treatment of ESCC.

Adult↗
PubMed2005

T-type Ca2+ channels are involved in high glucose-induced rat neonatal cardiomyocyte proliferation.

Infants develop hypertrophic cardiomyopathy in approximately 30% of diabetic pregnancies. We have characterized the effects of glucose on voltage-gated T-type Ca2+ channels and intracellular free calcium concentration, [Ca2+]i in neonatal rat cardiomyocytes. We found that T-type Ca2+ channel current density increased significantly in primary culture neonatal cardiac myocytes that were treated with 25 mM glucose for 48 h when compared with those that were treated with 5 mM glucose. High-glucose treatment also caused a higher Ca2+ influx elicited by 50 mM KCl in the myocytes. KCl-induced Ca2+ influx was attenuated when nickel was present. Real-time PCR studies demonstrated that mRNA levels of both alpha1G (Ca(v)3.1) and alpha1H (Ca(v)3.2) T-type Ca2+ channels were elevated after high-glucose treatment. High-glucose also significantly increased ventricular cell proliferation as well as the proportion of cells in the S-phase of the cell cycle; both effects were reversed by nickel or mibefradil. These results indicate that high glucose causes a rise in [Ca2+]i in neonatal cardiac myocytes by a mechanism that is associated with the regulation of the T-type Ca2+ channel activity.

Animals↗
PubMed2005

Mitochondrial phylogeography and subspecific variation in the red panda (Ailurus fulgens): implications for conservation.

The red panda (Ailurus fulgens) is an endangered species and its present distribution is restricted to isolated mountain ranges in western China (Sichuan, Yunnan, and Tibet provinces) and the Himalayan Mountains chain of Nepal, India, Bhutan, and Burma. To examine the evolutionary history across its current range, and to assess the genetic divergence among current subspecies and population structure among different geographic locations, we sequenced mitochondrial DNA from the control region (CR) and cytochrome (cyt) b gene for 41 individuals in Sichuan, Yunnan, Tibet of China, and Burma. 25 CR haplotypes (10 for cyt b) were identified from 11 geographic locations. Only three haplotypes were shared among sample localities, including one among current subspecies. Nine haplotypes were shared with the study of Su et al. [Mol. Biol. Evol. 18 (2001) 1070]. CR haplotype diversity was high (0.95+/-0.02) and nucleotide diversity among all haplotypes was relatively low (0.018+/-0.009). Phylogenetic confirmed trees show a shallow pattern with very little structure or statistical robustness. The application of two coalescent-based tests for population growth allowed us to interpret this phylogeny as the result of a recent population expansion. Analysis of molecular variance and nested clade analysis failed to detect significant geographic structure in both data sets. The lack of significant differentiation between subspecies does not indicate the presence of evolutionary significant units. We suggest that the present population structure has resulted from habitat fragmentation and expansion from glacial refugia. Due to its habitat requirements it is likely that the red panda has undergone bottlenecks and population expansions several times in the recent past. The present population may exhibit a pattern reminiscent of a relatively recent population expansion.

Animals↗
PubMed2005

Cloning, expression, purification, crystallization and preliminary crystallographic study of the protein module (BIV2-Helix) in the fusion core of bovine immunodeficiency-like virus (BIV) gp40.

The fusion core of bovine immunodeficiency virus (BIV) gp40 is proposed to be involved in membrane fusion. However, no crystal structures are yet available. A predicted protein module BIV2-Helix of BIVgp40 has been expressed in Escherichia coli and purified by chromatography. Recombinant BIV2-Helix was crystallized using the hanging-drop vapour-diffusion technique at 291 K. The crystals were grown in MPD and belonged to the primitive rhombohedral space group R3, with unit-cell parameters a = 39.17, b = 39.17, c = 295.05 A and two molecules per asymmetric unit. X-ray diffraction data were collected to 1.76 A in the home laboratory from a single crystal.

Cloning, Molecular↗