Biomedical subjects

Ming Jin

Publications and source records attributed to Ming Jin.

At least 37 records · Page 2Linked to original sources

PubMed2005

Toward functional proteomics of alveolar macrophages.

Alveolar macrophages (AM) belong to a phenotype of macrophages with distinct biological functions and important pathophysiological roles in lung health and disease. The molecular details determining AM differentiation from blood monocytes and AM roles in lung homeostasis are largely unknown. With the use of different technological platforms, advances in the field of proteomics have made it possible to search for differences in protein expression between AM and their precursor monocytes. Proteome features of each cell type provide new clues into understanding mononuclear phagocyte biology. In-depth analyses using subproteomics and subcellular proteomics offer additional information by providing greater protein resolution and detection sensitivity. With the use of proteomic techniques, large-scale mapping of phosphorylation differences between the cell types have become possible. Furthermore, two-dimensional gel proteomics can detect germline protein variants and evaluate the impact of protein polymorphisms on an individual's susceptibility to disease. Finally, surface-enhanced laser desorption and ionization (SELDI) time-of-flight mass spectrometry offers an alternative method to recognizing differences in protein patterns between AM and monocytes or between AM under different pathological conditions. This review details the current status of this field and outlines future directions in functional proteomic analyses of AM and monocytes. Furthermore, this review presents viewpoints of integrating proteomics with translational topics in lung diseases to define the mechanisms of disease and to uncover new diagnostic and therapeutic targets.

Electrophoresis, Gel, Two-Dimensional↗

PubMed2005

[Separation and determination of aconitine in medicine wine by reversed-phase high performance liquid chromatography].

OBJECTIVE: For the purpose of more accurate and rapid analysis of aconitine in medicine wine, a reversed-phase High Performance Liquid Chromatography (HPLC) method was developed. METHODS: Standard aconitine was added to the blank wine when the wine sample was pretreated. The pretreatment method of samples, the linear range, the precision, the recoveries in the plasma were investigated by using of white wine plasma spiked with standard aconitine. RESULTS: The linear range was 0.45 approximately 9.0 microg x mL(-1), r=0.998 8. The detective limit was 0.45 microg x mL(-1), The intra and inter-day precision of assay for aconitine were less than 3.1% and 4.7% (n=5) in wine respectively. The recoveries of aconitine were more (97.3+/-2.8)% in medicine wine. The HPLC method has been used to investigate the concentration of aconitine in one forensic medicine case. CONCLUSION: The HPLC method of quantitative analysis aconitine is rapid and sensitive. It is only in the 2.0 h that determination of aconitine in the medicine wine.

Aconitine↗

PubMed2005

[Development of an oxygen inhalation device with automatic control].

This article elaborates the working principle, composition and main functions of an intelligent oxygen inhalation device based on AT 89S51, which can not only detect and control oxygen flow in real time, but also control the output power of the humidifier and monitor the respiration state of the patient.

Automation↗

PubMed2004

Novel CuS nanofibers using organogel as a template: controlled by binding sites.

A new cholesterol organogelator 1 was synthesized, which was confirmed as an effective gelator for various organic solvents and could self-assemble into network fibers in some organic solvents. Moreover, gelator 1 could act as templates for the synthesis of various CuS nanofibers with different helical pitches. For example, when H(2)S was used as the sulfur source, straight and bending helical CuS nanofibers with a pitch of 100-200 nm could be fabricated in butyl acetate and benzene-butanol gel systems, respectively, while bending CuS nanofibers with a similar helical pitch (ca. 50 nm) could be obtained when thioacetamide was used as the sulfur source in both gel systems. It was first found that the morphologies of inorganic nanofibers could be controlled by the binding sites between the inorganic precursor and the organogel.

Binding Sites↗

PubMed2004

Essential role of B-helix calcium binding sites in annexin V-membrane binding.

Crystal structures of annexin V have shown up to 10 bound calcium ions in three different types of binding sites, but previous work concluded that only one of these sites accounted for nearly all of the membrane binding affinity of the molecule. In this study we mutated residues contributing to potential calcium binding sites in the AB and B helices in each of the four domains (eight sites in total) and in DE helices in the first, second, and third domains (three sites in total). We measured the affinity of each protein for phospholipid vesicles and cell membranes by quantitative calcium titration under low occupancy conditions (< 1% saturation of available membrane binding sites). Affinity was calculated from the midpoint and slope of the calcium titration curve and the concentration of membrane binding sites. The results showed that all four AB sites were essential for high affinity binding, as were three of the four B sites (in domains 1, 2, and 3); the DE site in the first domain made a slight contribution to affinity. Multisite mutants showed that each domain contributed additively and independently to binding affinity; in contrast, AB and B sites within the same domain were interdependent. The number of functionally important sites identified was consistent with the Hill coefficient observed in calcium titrations. This study shows an essential and previously unappreciated role for B-helix calcium binding sites in the membrane binding of annexins and indicates that all four domains of the molecule are required for maximum membrane binding affinity.

Amino Acid Sequence↗

PubMed2004

Novel pearl-necklace porous CdS nanofiber templated by organogel.

A new cholesterol organogelator 4 was synthesized and its gelation property was evaluated. It was confirmed that 4 was an effective gelator for various organic solvents and could self-assemble into network fibers with a bilayer of folded conformation in some organic solvents. Moreover, organogelator 4 could act as a template for the synthesis of novel pearl-necklace porous CdS nanofibers. The transcription process of organogel fibers into CdS nanofibers was investigated, and it was found that Cd2+ ions were coated on the organogel fibers by the interaction with ester groups of 4, which might lead to the change of the arrangement of the organogelator and seemed to serve as nucleation sites for metalization. The further growth of CdS began with these nucleation sites along the organogel fibers. Meanwhile, parts of 4 free from organogel fibers have an effect on the formation of the CdS nanofibers consisting of the network and wormlike CdS particles.

Journal Article↗

PubMed2004

Synthesis, self-assembly and characterization of a new glucoside-type hydrogel having a Schiff base on the aglycon.

A new hydrogel based on a substituted phenyl glucoside with a Schiff base in the aglycon was synthesized, and the self-assembling characteristics was studied. FTIR spectra, UV-vis absorption spectra and X-ray diffraction (XRD) revealed that pi-pi interactions between the Schiff base moieties, hydrogen bonds, and the interdigitated interactions between hydrophobic chains had effects on the formation of the self-assembling hydrogel. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) observation showed that the three-dimensional hydrogel network was constructed from nanotubes with inner diameters of ca. 75 nm and wall of ca. 20 nm.

Glucosides↗

PubMed2004

Proteome comparison of alveolar macrophages with monocytes reveals distinct protein characteristics.

Alveolar macrophages (AMs) are a subset of tissue macrophages situated in the alveolar milieu. Compared with their precursor blood monocytes, AMs exhibit distinct physiologic functions unique to their anatomic location. However, the molecular details that control monocyte differentiation into AMs remain unknown. This study employed a proteomic approach to define protein characteristics that distinguish AMs from monocytes. AMs and monocytes were obtained from six nonsmoking, healthy donors. Whole cell lysates from each donor's AMs and monocytes were analyzed by two-dimensional (2D) gel electrophoreses. The protein density for each protein spot in a 2D gel was compared between these two cell types. Proteins that demonstrated consistent level changes of greater than 2.5-fold in all six donors were subjected to tandem mass spectrometry for protein identity. Using this process, we revealed proteome changes in AMs that relate to their physiologic roles in proteolysis, actin reorganization, and cellular adaptation in the unique alveolar milieu. By comparison, blood monocytes displayed higher levels of the proteins involved in transcription, metabolism, inflammation, and in the control of proteolysis. These results provide new insights into the biology of mononuclear phagocytes and set a basis for future causality studies.

Adult↗

PubMed2004

Development of a large-scale HPLC-based purification for the urease from Staphylococcus leei and determination of subunit structure.

Coagulase-positive Staphylococcus species, related to but distinct from the genetic homology group containing Staphylococcus cohnii, Staphylococcus xylosus, and Staphylococcus saphrophyticus, were isolated from biopsy material obtained from a cluster of patients in Korea suffering from gastritis. The prototype isolate, Staphylococcus leei, has high urease activity that is similar with respect to a low K(m) value and acid resistance of the urease found in the stomach adapted pathogen, Helicobacter pylori. S. leei is remarkably resistant to lysis and only a small fraction of the cells are broken using sonication, a French press, Niro homogenizer, or a Gaulin mill. In the present report, we describe an efficient cell lysis procedure for S. leei using three passes through a Dynomill with 0.5mm glass beads that results in lysis of more than 95% of the cells. We also developed an efficient and large-scale purification procedure for the S. leei urease using a BioCAD HPLC Workstation using Q-Sepharose, Poros HP2, Sephacryl S-300, and hydroxyapatite chromatography. The urease of S. leei was purified 98-fold to a specific activity of 731U/mg. The urease protein is composed of three subunits, alpha (65kDa), beta (21kDa), and gamma (12kDa), and in situ enzyme assay and molecular sieve chromatography indicate that multiple high molecular weight forms are present, including an apparent pentamer of 1:1:1 alphabetagamma-heterotrimers of 480kDa. This purification procedure was used to purify 16mg of enzyme from 120-liters of cell culture. This improved lysis and purification procedure will make it possible to obtain sufficient quantities of urease for use as an antigen in ELISA assays to carry out studies to determine the incidence and demographic prevalence of gastritis due to S. leei.

Acrylic Resins↗

PubMed2004

Synthesis and characterization of nanostructural hydrogel and template for CdS nanofibers.

Hydrogels based on beta-D-glucopyranoside-substituent thiosemicarbazide derivatives were synthesized and used as template to fabricate netlike CdS nanofibers. The self-assembling properties of the hydrogels and their effect on the synthesis of CdS nanostructure were studied. Fourier transform infrared spectra, UV-visible absorption spectra and X-ray diffraction revealed that pi-pi stacking, hydrogen bonds and interdigitated interactions between hydrophobic chains had influence on the formation of self-assembled lamellar hydrogel. Transmission electron microscopic and electron diffraction observation showed the formation of hexagonal stacking nanofiber-based CdS semiconductor materials. The transmission electron microscopic pictures of the CdS nanostructure in difference growth stages revealed the growth mechanism of CdS nanofibers templated by hydrogel.

Cadmium Compounds↗

PubMed2004

[The cloning and expression of the truncated human bid gene and its pro-apoptotic effect on Hela cells].

AIM: To explore the expression of the truncated bid gene and its pro-apoptotic effect on Hela cells. METHODS: A full-length human bid gene was cloned by RT-PCR and confirmed by sequence analysis. By deleting the 60 amino acids of N-terminal the truncated bid (tbid) gene was obtained and then inserted into the eukaryotic expression vector pIRES2-EGFP. After the tbid gene was transfected into Hela cells under lipofectamine mediation, the effect of target gene expression on morphology and growth of Hela cells were observed under fluorescence and electron microscopes and analysed by TUNEL staining. RESULTS: pIRES2-EGFP containing tbid gene was constructed successfully. After Hela cells were transfected with GFP expression vector of tbid gene, tbid was expressed which was followed by decreased cell fluorescence intensity, poor cell growth, and cell death. Cell shrinkage and nuclear condensation, typical apoptotic characteristics, were observed by electron microscope observation and Tunel staining. CONCLUSION: The expression of tbid can effectively induce apoptosis of Hela cells.

Apoptosis↗

PubMed2004

[Inhibitory effect of kaempferol against binding of platelet activating factor to its receptor].

OBJECTIVE: To observe the platelet activating factor (PAF) antagonistic effect of kaempferol. METHOD: The specific binding of [3H] PAF to rabbit platelet receptor was investigatedwith radio ligand binding assay (RLBA). Platelet adhesion induced by PAF was measured with spectrophotometry. The elevation of inner free calcium concentration in rabbit polymorphonuclear leukocytes (PMNs) induced by PAF was determined with Fura-2 fluorescent technique. RESULT: The 1, 2 or 4 nmol x L(-1) [3H]PAF specific binding to rabbit platelet receptor was inhibited by Kae dosage dependently and the IC50 were 30.8, 74.6 and 92.0 micro mol x L(-1), respectively. The PAF induced reactions of rabbit platelet adhesion and PMNs inner free calcium concentration elevation were inhibited by Kae in a dose-dependent manner. The IC50 of Kae to inhibit platelet adhesion was 65 micromol x L(-1). CONCLUSION: Kae is effective in inhibiting the action of PAF and it is a new PAF receptor antagonist.

Animals↗

PubMed2004

[Study on the antioxidative effect of Safflor Yellow].

OBJECTIVE: To observe the antioxidative effect of Safflor Yellow (SY). METHOD: Hydroxyl radical scavenge effect of SY was tested with 1,10-phenanthroline-Fe2+ oxidative assay. Lipid peroxidation of mouse liver suspension was measured with thiobarbituric acid colorimetry technique. Hemocytocatheresis was determined with colorimetry. RESULT: Hydroxyl radical could be scavenged by 1.39 to 3.42 g x L(-1) SY dose dependently. Mouse liver suspension peroxidation was inhibited by 77.8 to 776.1 mg x L(-1) SY dosage dependently. Hemocytocatheresis was attenuated by 37.1 to 297.1 mg x L(-1) SY dose dependently. CONCLUSION: SY is an antioxidative part of Carthamus tinctorius.

Animals↗

PubMed2003

Specific tumoricidal activity of a secreted proapoptotic protein consisting of HER2 antibody and constitutively active caspase-3.

In this study, a novel approach to antitumor therapy was devised by generating a chimeric tumor-targeted killer protein, referred to as immunocasp-3, that comprises a single-chain anti-erbB2/HER2 antibody with a NH(2)-terminal signal sequence, a Pseudomonas exotoxin A translocation domain, and a constitutively active caspase-3 molecule. In principle, cells transfected with the immunocasp-3 gene would express and secrete the chimeric protein, which then binds to HER2-overexpressing tumor cells. Subsequent cleavage of the constitutively active capase-3 domain from the immunocasp-3 molecule and its release from internalized vesicles would lead to apoptotic tumor cell death. To test this strategy, we transduced human lymphoma Jurkat cells with a chimeric immunocasp-3 gene expression vector and showed that they not only expressed and secreted the fusion protein but also selectively killed tumor cells overexpressing HER2 in vitro. i.v. injection of the transduced Jurkat cells led to tumor regression in a mouse xenograft model because of continuous secretion of immunocasp-3 by the transduced cells. The growth of HER2-positive tumor cells in this model was inhibited by i.m. as well as intratumor injection of immunocasp-3 expression plasmid DNA, indicating that the immunocasp-3 molecules secreted by transfected cells have systematic antitumor activity. We conclude that the immunocasp-3 molecule, combining the properties of a tumor-specific antibody with the proapoptotic activity of a caspase, has potent and selective antitumor activity, either as cell-based therapy or as a DNA vaccine. These findings provide a compelling rationale for therapeutic protocols designed for erbB2/HER2-positive tumors.

Amino Acid Sequence↗

PubMed2003

Signalling and crosstalk of Rho GTPases in mediating axon guidance.

Axon extension during development of the nervous system is guided by many factors, but the signalling mechanisms responsible for triggering this extension remain mostly unknown. Here we have examined the role of Rho family small guanosine triphosphatases (GTPases) in mediating axon guidance by diffusible factors. Expression of either dominant-negative or constitutively active Cdc42 in cultured Xenopus laevis spinal neurons, at a concentration that does not substantially affect filopodial formation and neurite extension, abolishes the chemoattractive growth cone turning induced by a gradient of brain-derived neurotrophic factor that can activate Cdc42 and Rac in cultured neurons. Chemorepulsion induced by a gradient of lysophosphatidic acid is also abolished by the expression of dominant-negative RhoA. We also show that an asymmetry in Rho kinase or filopodial initiation across the growth cone is sufficient to trigger the turning response and that there is a crosstalk between the Cdc42 and RhoA pathways through their converging actions on the myosin activity essential for growth cone chemorepulsion.

Animals↗

PubMed2003

[Effect of Sorbaria Sorbifolia extract on anti-oxidative activities in rats with precancerosis induced by diethylnitrosamine].

OBJECTIVE: To study the effect of Sorbaria Sorbifolia extract on anti-oxidative activities in rats with precancerosis induced by diethylnitrosamine. METHODS: Sorbaria sorbifolia was perfused into stomach of rats with DEN-induced precancerosis, then the biochemical indexes were investigated. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and the concentrations of malondialdehyde (MDA), glutathione (GSH) were investigated by colorimetric method. RESULTS: Sorbaria sorbifolia extract increased SOD, GSH-PX and decreased MDA, GSH levels in serum and liver homogenate. CONCLUSION: Sorbaria Sorbifolia extract significantly increased anti-oxidative activities in rats with precancerosis induced by diethylnitrosamine.

Animals↗

PubMed2003

[Study on the inhibition of alpha-glucosidase by soyasaponins].

OBJECTIVE: To study the inhibitory effects of soyasaponins on alpha-glucosidase (EC3.2.1.20). METHODS: Soyasaponins were isolated by ODS column chromatography and high-performance liquid chromatography (HPLC) from hypocotyls of soybean. The inhibitory activities of each component of soyasaponins against alpha-glucosidase were tested by colorimetric method. RESULTS: Soyasaponins showed potent inhibitory activities against alpha-glucosidase. Group B, group E and DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one) saponins showed stronger potency, which were non-competitive inhibitors of alpha-glucosidase with IC50 values of 10-40 mumol/L. While group A saponins showed a little lower potency with IC50 values of about 2 mmol/L. CONCLUSION: The results suggest soyasaponins, which exhibit inhibitory effects on alpha-glucosidase, seem physiologically useful for suppressing postprandial hyperglycemia in patients with diabetes mellitus.

Chromatography, High Pressure Liquid↗

PubMed2003

[Antagonistic effect of myricetin on platelet activing factor].

AIM: To study the antagonistic effect of myricetin on platelet activing factor (PAF). METHODS: The specific binding of [3H] PAF to rabbit platelet receptor was investigated using radio ligand binding assay (RLBA). Platelet adhesion induced by PAF was measured with spectrophotometry. The elevation of inner free calcium concentration in rabbit polymorphonuclear leukocytes (PMNs) induced by PAF was assayed by Fura-2 fluorescent technique. RESULTS: The specific binding inhibition potency of Myr was found to be concentration-dependent. The IC50 of Myr in [3H] PAF 1, 2 and 4 nmol.L-1 were 34.8, 85.7 and 118.6 mumol.L-1, respectively. The PAF induced reactions of rabbit platelet adhesion and PMNs inner free calcium concentration increase were inhibited by Myr in a dose-dependent manner. The IC50 of Myr to inhibit platelet adhesion was 13.1 mumol.L-1. CONCLUSION: The specific receptor binding of PAF can be antagonized by myricetin.

Animals↗