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Biomedical subjects

Tao Liu

Publications and source records attributed to Tao Liu.

At least 163 records · Page 9Linked to original sources
PubMed2003

[Assessment of health-related quality of life in cured SARS patients].

OBJECTIVE: To assess the quality of life in cured patients with severe acute respiratory syndrome (SARS). METHODS: One hundred and nineteen SARS outpatients, including 64 men and 55 women, with mean age (34.1 +/- 11.4) years and average days of discharge from hospital (28.0 +/- 12.8) days, were assessed by the St George's respiratory questionnaire (SGRQ), and 72 patients with spirometry test. RESULTS: The patients had a moderately degree physiological impairment and increased SGRQ score. Scores of all four part of SGRQ correlated significantly with diffuse capacity of the lung for carbon monoxide/pre (DLco%). The correlation coefficients between the activation, impaction, total score, and diffuse capacity of the lung for carbon monoxide/alveolar ventilation/pre (DLco/Va%) were resembled (r = 0.47-0.54, P < 0.01). There was a significant relationship between the score of SGRQ and patients age, and gender. The time leaving hospital only had a significant relationship with the symptom score of SGRQ. CONCLUSIONS: SGRQ is a sensitive tool for assessing quality of life in cured SARS patients. The cured SARS patients' quality of life decrease moderately.

Adolescent↗
PubMed2003

[Assessment of pulmonary function in SARS patients during the convalescent period].

OBJECTIVE: To investigate the pulmonary function in severe acute respiratory syndrome (SARS) patients during the convalescent period. METHODS: Followup 89 outpatients of SARS. The follow-up study included interview, physical examination, and pulmonary function test. RESULTS: The interval between hospital discharge and functional assessment was 1.75 +/- 0.53 months (0.5-3.4 months). Mild to moderate abnormalities in pulmonary function were found in 48 patients (53.9%). Diffusion capacity for carbon monoxide (DLco) was impaired in 38 patients (42.7%); in 7 patients (7.9%), lung function was restrictive defect combined DLco impairment; Other patterns of impairment were revealed in 3 patient. Dyspnea during acute phase and CT during the convalescent period were found to have significant influences on DLco and total lung capacity (TLC). CONCLUSIONS: Diffusing capacity impairment as well as restrictive defect persist in convalescence SARS.

Adolescent↗
PubMed2002

Rapid excited-state structural reorganization captured by pulsed X-rays.

Visible light excitation of [Cu(I)(dmp)(2)](BArF), where dmp is 2,9-dimethyl-1,10-phenanthroline and BArF is tetrakis(3,5-bis(trifluoromethylphenyl))borate, in toluene produces a photoluminescent, metal-to-ligand charge-transfer (MLCT) excited state with a lifetime of 98 +/- 5 ns. Probing this state within 14 ns after photoexcitation with pulsed X-rays establishes that a Cu(II) center, borne in a Cu(I) geometry, binds an additional ligand to form a five-coordinate complex with increased bond lengths and a coordination geometry of distorted trigonal bipyramid. The average Cu-N bond length increases in the excited state by 0.07 A. The transiently formed five-coordinate MLCT state is photoluminescent under the condition studied, indicating that the absorptive and emissive states have distinct geometries. The data represent the first X-ray characterization of a molecular excited state in fluid solution on a nanosecond time scale.

Journal Article↗
PubMed2002

Non-steroidal pregnancy-terminating agents: design, synthesis and structure-activity relationships of 2-aryl-1,2,4-triazolo[1,5-a]pyridine.

The syntheses and the pregnancy-terminating activity relationships of compounds -n are reported. Compounds 5b and are found to be more potent than DL-111-a known drug having effective pregnancy-terminating activity in vitro. Further research shows compounds 5b and have the same activity as DL-111 in vivo. We also found an exciting result that they have excellent anti-implantation activity after oral administration.

Abortifacient Agents, Nonsteroidal↗
PubMed2002

Sensitivity enhancement of DNA sensors by nanogold surface modification.

A novel amplified microgravimetric gene sensing system was developed using quartz crystal microbalance modified by gold nanoparticles anchored on its 1,6-hexanedithiol modified gold electrode surface, and ultrasensitive detection of DNA hybridization was accomplished at the level of at least 2 x 10(-16) M.

Biosensing Techniques↗
PubMed2002

Concentration in plasma of macrophage inhibitory cytokine-1 and risk of cardiovascular events in women: a nested case-control study.

BACKGROUND: Macrophage inhibitory cytokine-1 (MIC-1) is part of the TGF-beta superfamily. Raised concentrations of MIC-1 in serum arise in several disease states, can be detected in normal individuals, and can partly be genetically determined. We aimed to investigate whether MIC-1 has a role in atherothrombosis. METHODS: We did a prospective, nested, case-control study in 27628 initially healthy women. Of these women, we established baseline concentrations of MIC-1 in 257 who subsequently had myocardial infarction, stroke, or died from a cardiovascular event (cases) and in 257 matched for age and smoking status, who did not report cardiovascular disease during 4-year follow-up (controls). We also assessed polymorphisms in the MIC-1 gene (MIC-1 H and MIC-1 D) in all 514 women. FINDINGS: MIC-1 concentrations were higher at baseline in women who subsequently had cardiovascular events than in those who did not (618 vs 538 pg/mL, p=0.0002). Concentrations above the 90th percentile (>856 pg/mL) were associated with a 2.7-fold increase in risk (95% CI 1.6-4.9, p=0.001). This effect was independent of traditional cardiovascular risk factors and at least additive to that of C-reactive protein. There was no significant association between MIC-1 polymorphism and vascular events. INTERPRETATION: MIC-1 could be a novel target for cardiovascular disease prevention.

Cardiovascular Diseases↗
PubMed2002

Targeted gene therapy with CD40Ig to induce long-term acceptance of liver allografts.

BACKGROUND: The purpose of this study was to modulate the immune response of rat liver transplant recipients by adenovirus-mediated gene transfer of CD40Ig, a secretable fusion protein designed to block the CD40-CD154 T-cell costimulation pathway. METHODS: CD40Ig complementary DNA was created by joining the reverse transcriptase-polymerase chain reaction complementary DNA products for the extracellular domain of murine CD40 to the Fc portion of murine IgG2a. AdCD40Ig and AdSIg (IgG2a-Fc control) recombinant adenoviruses were used to transduce donor liver grafts before nonarterialized orthotopic rat liver transplantation. Donor specific unresponsiveness was examined with skin transplants. RESULTS: All rats (n = 6) that received liver allografts transduced with AdCD40Ig survived >100 days with normal liver histology. Serum levels of CD40Ig at 10, 30, 60, and 100 days after transplantation ranged from 100 to 500, 100 to 250, 5 to 40, and 2 to 10 microg/mL, respectively. Mean survival of rats (n = 4) that received liver allografts transduced with AdSIg control adenovirus was 9.25 +/- 2.9 days. Long-term survivors were rechallenged with skin grafts 100 days after liver transplantations. Survival was 72, >100 (x4) days for donor specific allogeneic skin grafts and 14, 14, 18, 19, and 21 days for third-party allogeneic skin grafts. CONCLUSIONS: Adenovirus-mediated gene transfer of CD40Ig into cold-preserved liver allografts before transplantation results in high levels of transgene expression with resultant long-term survival of hepatic allografts and donor specific unresponsiveness.

Adenoviridae↗
PubMed2002

Protein isoforms observed by ultrahigh resolution capillary isoelectric focusing electrospray ionization mass spectrometry.

On-line coupling of capillary isoelectric focusing (CIEF) to electrospray ionization mass spectrometry (ESI-MS) as a two-dimensional separation/analysis system was employed for high-resolution analysis of the protein isoforms observed during CIEF process. The analytical system was established by using neutral coated long capillary (80 cm), active capillary positioning and sheath-liquid interface. Proteins were separated and resolved in CIEF according to their differences in isoelectric point (pI), and then characterized by ESI-MS. The focused protein zones were eluted to the entrance of MS by combining cathodic mobilization with gravity. The ultrahigh resolution (difference in pI<0.04) of this technique obtained under certain conditions led to the detection of three isoforms in hemoglobin A and in sickle cell hemoglobin (with similar charge distribution and same molecular weight, but their differences in pIranging from 0.04 to 0.08) and two isoforms of beta-lactoglobulin A (difference in pI is 0.6). The isoelectric points, relative amounts, and molecular masses of these isoforms were determined simultaneously by CIEF-ESI-MS.

Carbonic Anhydrase II↗
PubMed2002

[Effect of staphylococcal enterotoxin B on ion electrophysiology and permeability in rabbit maxillary sinus epithelium].

OBJECTIVE: To study the barrier role of staphylococcal enterotoxin B (SEB) in rabbit maxillary sinus mucosa. METHODS: Rabbit maxillary sinus mucosal membrane was dissected under a surgical microscope. The short-circuit current (Isc), conductance (G) and its permeability to horseradish peroxidase (HRP) were evaluated by employing Ussing chamber technique. RESULTS: The stimulation of SEB enhanced Isc, G and its permeability to HRP of sinus epithelial barrier. The same results were obtained by applying tumor necrosis factor alpha (TNF-alpha) to rabbit maxillary sinus. Increase in TNF-alpha level in sinus mucosa was observed by the stimulation of SEB. Those pathophysiological abnormalities of sinus mucosa were abolished by pretreatment with anti-TNF-alpha antibody. CONCLUSION: The SEB has potential effects on rabbit maxillary sinus mucosal barrier, activates the immune cells in the mucosa, and plays certain roles in maxillary sinusitis.

Animals↗
PubMed2001

[Therapeutic Effects of Lishengsu on Chemotherapy Induced Leukopenia in Patients with Malignant Tumor]

To observe therapeutic effects of Lishengsu (recombinant human granulocyte colony stimulating factor, rhG-CSF) on leukopenia induced by chemotherapy, 40 patients with malignant tumor included in the clinical observation were randomly divided into group A and B (20 patients each). Each patient was received two cycles of chemotherapy. In group A Lishengsu was administered in the first cycle and none in the second cycle, while in group B Lishengsu was given in the second cycle, but not in the first cycle. Lishengsu was subcutaneoasly injected for 5 - 7 days at dosage of 75 micro g or 150 micro g per day 24 - 48 hours after completion of chemotherapy. The results showed that Lishengsu remarkably alleviated the degree of leukopenia and neutropenia, and lower the incidence of infection. The curative effect of Lishengsu is reliable with slight side-effects, and it might assist to completion of chemotherapy in tumor patiants.

Journal Article↗
PubMed1999

Free radicals contribute to the reduction in peripheral vascular responses and the maintenance of thermal hyperalgesia in rats with chronic constriction injury.

We previously reported that the time frame and the extent of the changes in the peripheral neurogenic inflammatory response in the skin area, innervated by an injured nerve, coincide with those of pain behaviours. We raised the possibility that common factors might operate to modulate neuropathic pain and peripheral neurogenic processes in rats with chronic constriction nerve injury (CCI). In the present study we examined the role of free radicals in modulating the neurogenic vascular response and thermal hyperalgesia in rats with CCI of the sciatic nerve. Free radicals, via an interaction with nitric oxide (NO) to form peroxynitrite, have previously been implicated in the maintenance of thermal hyperalgesia in CCI rats. In this study, we induced CCI of the sciatic nerve and the activity of xanthine oxidase (XO), which catalyzes the formation of superoxide anions, was measured in the injured nerve. In addition, we examined the effect of antioxidants on thermal hyperalgesia and on the neurogenic vascular response to substance P (SP) perfused over the base of a blister induced on the hind footpad skin which is innervated by the injured sciatic nerve. Compared with the sham operated group, CCI rats had a significantly higher XO activity in the injured sciatic nerve and significantly reduced thermal threshold and peripheral neurogenic vascular response to SP. Treatment with antioxidants, superoxide dismutase (SOD) or tirilazad significantly improved the neurogenic vascular response while tirilazad treatment significantly alleviated thermal hyperalgesia. The results therefore, suggest that free radicals are elevated in CCI animals and that they contribute to the maintenance of thermal hyperalgesia and the reduction in peripheral microvascular blood flow in the area innervated by the injured nerve. We raise the possibility that common mechanisms may govern the changes in neuropathic pain and in the peripheral neurogenic vascular responses in tissues innervated by the injured nerve.

Animals↗
PubMed1999

Application of Free-flow Electrophoresis to the Separation of Murine Lymphocytes.

Free-flow electrophoresis offers not only the all-in-solution separation process but also very gentle separation conditions, and it can be used for continuous separation and preparation, so it has been widely applied in the fields of biochemistry and cell biology. Using this technique to separate insoluble particles such as cells, both high separation efficiency and high activity and viability could be obtained. Murine lymphocytes were separated in low ionic strength triethanolamine buffer by free-flow electrophoresis, the cell fractions were detected and characterized by means of UV spectrometry, immune fluorescence labeling and flow cytometry. Results indicated that T and B lymphocytes were well separated with high viability.

Journal Article↗
PubMed1999

Protein and Peptide Identification by Capillary Zone Electrophoresis-Tandem Mass Spectrometry.

A method for highly sensitive protein and peptide identification by capillary zone electrophoresis/electrospray ionization-tandem mass spectrometry (CZE/ESI/MS/MS) was described. A mixture of peptides Met-enkephalin and Leu-enkephalin was analyzed, and their amino acid sequences were identified, respectively, using CZE/MS/MS. Peptide mapping for a tryptic digest of horse cytochrome c was performed by the same method. The results indicated that almost all peptides generated by tryptic digestion were identified, and their sequences were interpreted by their collision-induced (CID) mass spectra. Applying the uninterpreted CID spectra of the protein digest to searching in sequence database by the SEQUEST program could identify proteins conveniently and rapidly. The samples consumed in the CZE/MS/MS experiments were at picomole level, so this method is quite suitable for quality control of recombinant proteins and trace amount protein identification in the proteome research.

Journal Article↗
PubMedDate not supplied

Molecular binding behavior of pyridine-2,6-dicarboxamide-bridged bis(beta-cyclodextrin) with oligopeptides: switchable molecular binding mode.

Bridged bis(beta-cyclodextrin) 1 with a pyridine-2,6-dicarboxamide linker was synthesized, and its inclusion complexation behavior with some aliphatic oligopeptides was investigated in aqueous buffer solution of pH 2.0 and 7.2 at 25 degrees C by means of circular dichroism, fluorescence, and 2D NMR techniques. The results show that the resulting inclusion complexes of 1 with oligopeptides adopt a cooperative "cyclodextrin-guest-cyclodextrin" sandwich binding mode in a neutral media, but a "guest-linker-cyclodextrin" coinclusion binding mode in an acidic media. These switchable binding modes consequently rationalize the binding ability of bis(beta-cyclodextrin) 1 at different pH values; that is, 1 shows the stronger association with oligopeptides in a neutral media. Because of the simultaneous contributions of hydrophobic, hydrogen bond, and electrostatic interactions, bis(beta-cyclodextrin) 1 affords length-selectivity up to 4.7 for the Gly-Gly/Gly-Gly-Gly pair at pH 2.0 and sequence-selectivity up to 4.2 for the Gly-Leu/Leu-Gly pair at pH 7.2. These phenomena are discussed from the viewpoint of the size-fit concept and the multipoint recognitions between host and guest.

Binding Sites↗
PubMedDate not supplied

Probability-based evaluation of peptide and protein identifications from tandem mass spectrometry and SEQUEST analysis: the human proteome.

Large-scale protein identifications from highly complex protein mixtures have recently been achieved using multidimensional liquid chromatography coupled with tandem mass spectrometry (LC/LC-MS/MS) and subsequent database searching with algorithms such as SEQUEST. Here, we describe a probability-based evaluation of false positive rates associated with peptide identifications from three different human proteome samples. Peptides from human plasma, human mammary epithelial cell (HMEC) lysate, and human hepatocyte (Huh)-7.5 cell lysate were separated by strong cation exchange (SCX) chromatography coupled offline with reversed-phase capillary LC-MS/MS analyses. The MS/MS spectra were first analyzed by SEQUEST, searching independently against both normal and sequence-reversed human protein databases, and the false positive rates of peptide identifications for the three proteome samples were then analyzed and compared. The observed false positive rates of peptide identifications for human plasma were significantly higher than those for the human cell lines when identical filtering criteria were used, suggesting that the false positive rates are significantly dependent on sample characteristics, particularly the number of proteins found within the detectable dynamic range. Two new sets of filtering criteria are proposed for human plasma and human cell lines, respectively, to provide an overall confidence of >95% for peptide identifications. The new criteria were compared, using a normalized elution time (NET) criterion (Petritis et al. Anal. Chem. 2003, 75, 1039-1048), with previously published criteria (Washburn et al. Nat. Biotechnol. 2001, 19, 242-247). The results demonstrate that the present criteria provide significantly higher levels of confidence for peptide identifications from mammalian proteomes without greatly decreasing the number of identifications.

Blood Proteins↗