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Qi Liu

Publications and source records attributed to Qi Liu.

At least 37 records · Page 2Linked to original sources
PubMed2006

Generalized three-dimensional windowed Fourier transform for fringe analysis.

A 3D windowed Fourier transform is proposed for fringe sequence analysis, which processes the joint spatial and temporal information of the fringe sequence simultaneously. The 2D windowed Fourier transform in the spatial domain and the 1D windowed Fourier transform in the temporal domain are two special cases of the proposed method. The principles of windowed Fourier filtering and windowed Fourier ridges are developed. Experimental verification shows encouraging results despite a longer processing time.

Journal Article↗
PubMed2006

Insights into the coupling of duplication events and macroevolution from an age profile of animal transmembrane gene families.

The evolution of new gene families subsequent to gene duplication may be coupled to the fluctuation of population and environment variables. Based upon that, we presented a systematic analysis of the animal transmembrane gene duplication events on a macroevolutionary scale by integrating the palaeontology repository. The age of duplication events was calculated by maximum likelihood method, and the age distribution was estimated by density histogram and normal kernel density estimation. We showed that the density of the duplicates displays a positive correlation with the estimates of maximum number of cell types of common ancestors, and the oxidation events played a key role in the major transitions of this density trace. Next, we focused on the Phanerozoic phase, during which more macroevolution data are available. The pulse mass extinction timepoints coincide with the local peaks of the age distribution, suggesting that the transmembrane gene duplicates fixed frequently when the environment changed dramatically. Moreover, a 61-million-year cycle is the most possible cycle in this phase by spectral analysis, which is consistent with the cycles recently detected in biodiversity. Our data thus elucidate a strong coupling of duplication events and macroevolution; furthermore, our method also provides a new way to address these questions.

Animals↗
PubMed2006

Construction and immunogenicity of a recombinant fowlpox virus containing the capsid and 3C protease coding regions of foot-and-mouth disease virus.

Foot-and-mouth disease virus (FMDV) is an important pathogen with worldwide economic consequences. Consequently, an important goal is the development of a vaccine that can provide rapid protection while overcoming the potential risk associated with the production of conventional inactivated vaccines. An important secondary feature of the vaccine would be the ability to distinguish vaccinated from infected animals. A recombinant fowlpox virus (vUTAL3CP1) containing FMDV capsid polypeptide and 3C coding regions of O/NY00 was constructed and evaluated for its ability to induce humoral and cellular responses in mice and guinea pigs. In addition, the ability to protect guinea pigs against homologous virus challenge was examined. Mice and guinea pigs were given booster vaccinations twice and once, respectively, and guinea pigs were challenged 20 days after the booster vaccination. Control groups included animals inoculated with commercial vaccine, fowlpox virus or phosphate-buffered saline (PBS). All animals vaccinated with vUTAL3CP1 developed specific anti-FMDV antibody and neutralizing antibody, as well as T lymphocyte proliferation response and CTL cytotoxic activity. Three of four guinea pigs vaccinated with vUTAL3CP1 were completely protected from viral challenge. The results demonstrated the potential of a fowlpox virus-based recombinant FMD vaccine.

3C Viral Proteases↗
PubMed2006

[Clinical value of videomediastinoscopy in diagnosis of mediastinal disease].

OBJECTIVE: To evaluate the role of videomediastinoscopy in the diagnosis of disease of the mediastinum. METHODS: We retrospectively reviewed the clinical records of the 115 patients who underwent videomediastinoscopy. Local anesthesia or general anesthesia was employed. This operation consisted of cervical videomediastinoscopy in 102 patients, parasternal videomediastinoscopy in 13 patients, ninety-one patients had videomediastinoscopy for diagnosis of isolated mediastinal mass or lymphadenopathy, 25 patients with non small cell lung cancer or suspected lung cancer showed enlarged mediastinal lymph nodes radiographically in the chest. RESULTS: Among the patients with mediastinal disease, sarcoidosis was diagnosed in 37 patients, tuberculosis in 14 patients, lymphoma in 15 patients, nodal metastasis in 18 patients, noncaseating granulomata without classical "sarcoid" in 6 patients, with the accuracy of 93.3% (84/90); and staging of lung cancer in 25 patients, with the accuracy of 100% (25/25). The total accuracy of videomediastinoscoy and CT was 94.8% (109/115), 56.5% (65/115), respectively. Mean operative time was 26 min. There was neither complication nor mortality. CONCLUSION: videomediastinoscopy is a safe and effective procedure for the diagnosis of mediastinal disease and the staging of lung cancer.

Adolescent↗
PubMed2006

Selective inhibitors for phosphodiesterase 3 and 4 in antigen-induced increase of cough reflex sensitivity in guinea pigs.

Effects of the selective phosphodiesterase 3 (PDE3) inhibitor olprinone and the selective PDE4 inhibitor SB207499 were investigated on antigen-induced increase of cough reflex sensitivity and normal cough response to capsaicin in guinea pigs. Number of coughs elicited by inhalation of capsaicin (10(-8), 10(-6) and 10(-4)M) was counted 24h after an antigen challenge in actively sensitized guinea pigs, and then bronchoalveolar lavage (BAL) was performed. Olprinone (1 or 10mg/kg) or SB207499 (1 or 10mg/kg) was given twice intraperitoneally: One hour after the antigen challenge and 1h before the capsaicin provocation. SB207499, but not olprinone, significantly reduced both antigen-induced increase of cough response to inhaled capsaicin in sensitized animals and normal cough response in non-sensitized animals. SB207499, but not olprinone, also reduced the antigen-induced BAL eosinophilia. PDE4 inhibitors may be useful in treating cough associated with airway allergy via inhibiting both allergic airway inflammation and the common pathway of cough reflex.

Allergens↗
PubMed2006

Reexamining the functions of zinc sulfate as a selective depressant in differential sulfide flotation--the role of coagulation.

Zinc sulfate is a well-known selective depressant for zinc sulfide minerals such as sphalerite during the flotation of complex Cu-Pb-Zn sulfide ores. It deactivates sphalerite flotation by substituting the activating metal ions, and depresses sphalerite flotation by forming hydrophilic coatings of zinc hydroxyl species on sphalerite surfaces. However, we recently observed that zinc sulfate could also induce coagulation of fine sphalerite particles and such coagulation significantly reduced the mechanical entrainment of the fine sphalerite. Therefore, it seems that the effectiveness of zinc sulfate as a selective sphalerite depressant is not only due to its ability to make mineral surface hydrophilic, which reduces genuine flotation, but also due to its ability to coagulate the mineral, which reduces mechanical entrainment. Zinc sulfate is a "dual function" selective flotation depressant.

Journal Article↗
PubMed2006

The role of 11C-choline positron emission tomography-computed tomography and videomediastinoscopy in the evaluation of diseases of middle mediastinum.

BACKGROUND: Middle mediastinal masses comprise a wide variety of tumors but may also reflect lymphadenopathy, and thus remain an interesting diagnostic challenge. We performed positron emission tomography (PET) of mediastinal masses in order to evaluate the ability of PET to predict the malignancy of these tumors. We compared histologic findings, videomediastinoscopy, computed tomography (CT), and PET-CT in patients with mediastinal disease. METHODS: Thirty-two patients were evaluated with CT, PET-CT and videomediastionoscopy, and all studies were performed within four weeks in each patient. (11)C-choline as a PET tracer was used to visualize masses. PET data were evaluated using the standardized uptake value (SUV) and were compared with pathologic data. RESULTS: There were 13 men and 19 women aged from 21 to 74 (mean 45.2) years. Among the patients with mediastinal diseases, sarcoidosis was diagnosed in 12 patients, tuberculosis in 5 patients, lymphoma in 5 patients, and noncaseating granulomata without classical "sarcoid" finding in 3 patients. N2 or N3 nodal metastasis was revealed in 6 of 7 patients who had non-small cell lung cancer or suspected lung cancer, and one was negative (the pathological diagnosis was reactive hyperplasia). The accuracies for correctly diagnosing mediastinal masses for CT, PET-CT and videomediastinoscopy were 38% (12/32), 63% (20/32), and 91% (29/32) respectively. The diagnostic accuracy of videomediastinoscopy was superior to that of PET-CT (chi(2) = 11.130, P < 0.001). The SUVs were similar among these diseases. On the other hand, if the diagnostic classification was benign vs malignancy, the accuracies for CT, PET-CT and videomediastinoscopy were 53% (17/32), 75% (24/32), 100% (32/32) respectively. The diagnostic accuracy of videomediastinoscopy was superior to that of PET-CT (chi(2) = 22.042, P < 0.001). The SUV of malignant lesions (6.9, 3.2 - 9.8; n = 11) appeared to be higher than that of benign lesions (4.9, 2.9 - 8.3; n = 21), however, this difference was not statistically significant (P = 0.054). CONCLUSIONS: To diagnose lesions located in the middle mediastinum, videomediastinoscopy possesses the highest diagnostic accuracy, and therefore remains the gold standard. PET-CT is valuable for differential diagnosis of benign vs malignant lesions, CT alone or PET alone (SUV) may provide misdiagnosis in a substantial proportion of patients with mediastinal masses.

Adult↗
PubMed2006

Improvement of overall and failure-free survival in stage IV follicular lymphoma: 25 years of treatment experience at The University of Texas M.D. Anderson Cancer Center.

PURPOSE: Advanced-stage follicular lymphoma is considered incurable. The pace of improvements in treatment has been slow. This article analyzes five sequential cohorts of patients with stage IV follicular lymphoma treated between 1972 and 2002. METHODS: Five consecutive studies (two were randomized trials) involving 580 patients were analyzed for overall survival (OS), failure-free survival (FFS), and survival after first relapse. A proportional hazards analysis, and subset analyses using the follicular lymphoma international prognostic index (FLIPI) score were performed. Treatment regimens included: cyclophosphamide, doxorubicin, vincristine, prednisone, bleomycin (CHOP-Bleo); CHOP-Bleo followed by interferon alfa (IFN-alpha); a rotation of three regimens (alternating triple therapy), followed by IFN-alpha; fludarabine, mitoxantrone, dexamethasone (FND) followed by IFN-alpha; and FND plus delayed versus concurrent rituximab followed by IFN-alpha. RESULTS: Improvements in 5-year OS (from 64% to 95%) and FFS (from 29% to 60%) indicate steady progress, perhaps partly due to more effective salvage therapies, but the FFS data also indicate improved front-line therapies; these observations held true after controlling for differences in prognostic factors among the cohorts. The FLIPI model adds rigor to and facilitates comparisons among the different cohorts. An unexpected finding in this study was a trend toward an apparent FFS plateau. CONCLUSION: Evolving therapy, including the incorporation of biologic agents, has led to stepwise significant outcome improvements for patients with advanced-stage follicular lymphoma. The apparent plateau in the FFS curve, starting approximately 8 to 10 years from the beginning of treatment, raises the issue of the potential curability of these patients.

Adult↗
PubMed2006

Mechanical stiffness of segmental versus nonsegmental pedicle screw constructs: the effect of cross-links.

STUDY DESIGN: A biomechanical study in porcine spines of the construct stiffness effects of segmental pedicle screws. Stiffness effects of supplementation of nonsegmental screw constructs with cross-links was also evaluated. OBJECTIVE: To assess the biomechanical differences between constructs using segmental versus nonsegmental pedicle screw-based instrumentation as well as the effect of cross-links. SUMMARY OF BACKGROUND DATA: An in vitro biomechanical comparison of segmental versus nonsegmental pedicle screw constructs with and without cross-links using porcine lumbar vertebrae was performed. Mechanical trade-offs of reducing the number of pedicle screws in a given construct and substituting a cross-link for a pair of screws are not well understood. METHODS: Three, 4, and 5-vertebral segments from 18 porcine spines were instrumented with segmental and nonsegmental pedicle screw constructs, and with nonsegmental screws augmented with cross-links. Unconstrained biomechanical testing in flexion, extension, and axial rotation with 6 degree-of-freedom motion tracking was performed. Statistical comparisons of stiffness data were conducted using 2-tailed paired t tests. RESULTS: There was a statistically significant increase in stiffness between models with segmental pedicle screws compared to nonsegmental pedicle screws in 6 of the 9 mechanical tests. The remaining 3 tests approached but did not reach statistical significance (P = 0.087, 0.062, and 0.078). When cross-links were added to the nonsegmental models, differences in stiffness compared to segmental pedicle screws were largely eliminated, decreasing well below statistical significance in 8 of 9 tests. The highest difference in nonsegmental models with cross-links and segmental pedicle screw models was observed for the 5-vertebrae fusion models, for which axial rotation testing maintained statistically significant differences (P = 0.006), and flexion testing approached significance (P = 0.062). CONCLUSIONS: Segmental pedicle screw constructs increased mechanical stiffness compared to nonsegmental constructs in our fusion models. Placement of a single cross-link with nonsegmental screws eliminated statistical differences for 3 and 4-vertebral level constructs, and may be a satisfactory alternative in this clinical setting. Caution in applying these results inlonger constructs is recommended, given persistent increased stiffness found for the segmental 5-vertebral level models.

Animals↗
PubMed2006

MDDD, a 4,9-diazapyrenium derivative, is selectively toxic to glioma cells by inducing growth arrest at G0/G1 independently of p53.

4-Methyl-2,7-diamino-5,10-diphenyl-4,9-diaz-apyrenium chloride (MDDD), a stable and water soluble nucleic acid-intercalating agent, was shown to be toxic to cancer cells with IC50 around 10 microM. IC(50) We tested MDDD for its potential antitumor activities and found it inhibited cancer cell growth with IC(50) in the micromolar range for the majority of cancer cells tested, with the exception of glioma cells, for which the IC(50) is in the submicromolar range. This unique selectivity of MDDD to glioma cells can potentially be exploited for anti-glioma therapeutics. Although the underlying mechanisms for the apparent glioma specificity remain to be elucidated, our analysis indicates that MDDD significantly reduces cell clonogenicity and blockes cell proliferation at the G1 phase. MDDD treatment also triggers induction of p53 and p21 at the protein levels, suggesting the activation of DNA damage response. However, MDDD mediated growth inhibition does not require the p53 pathway since p53+/- isogenic cell pairs display the same sensitivity. These properties of MDDD favor its candidacy for evaluation as a new anti-tumor agent, particularly for glioma.

Animals↗
PubMed2006

[Construction and expression of fusion gene encoding Hyper-IL-6 in mammalian cells].

AIM: To construct and express fusion gene encoding Hyper-IL-6 in mammalian cells. METHODS: Using geneSOEing method, human sIL-6R cDNA was fused with IL-6 cDNA by a linker rich in glycine through PCR technique and cloned into pIRES(2)-EGFP. The constructed plasmid was transfected into mammalian cells. The expression of fusion gene encoding Hyper-IL-6 was detected by GFP and RT-PCR and immunocytochemistry. RESULTS: The recombinant plasmid pIRES-HIL-6 was successfully constructed and expressed in mammalian cells. CONCLUSION: The success in construction and expression of human Hyper-IL-6 makes it possible to further study its biological functions.

Animals↗
PubMed2006

[Development of novel cell delivery carrier for periodontal regeneration in vitro].

OBJECTIVE: To investigate the development of novel cell delivery carriers and evaluate the effects of platelet-rich plasma (PRP) and platelet-poor plasma (PPP) on cellular attachment and proliferation. METHODS: Rat gingival fibroblasts, periodontal ligament fibroblasts and osteoblasts were cultured in vitro. The biodegradable membranes were treated with PRP and PPP that were obtained from rat whole blood by gradient density centrifugation. The cellular attachment, proliferation and morphology on the untreated membranes and membranes treated with PRP and PPP were tested in vitro for 48 hours. RESULTS: There were significant differences between the untreated membranes and the membranes treated with PRP and PPP for three kinds of rat cells used in the experiment. There were no significant differences between those membranes treated with PRP and those treated with PPP. Three kinds of cells on the membranes treated with PRP were slight higher than those on the membranes treated with PPP. There were no significant differences in the same group for cells attachment. The rate of different cells proliferation on the untreated membranes was significant lower than those on the membranes treated with PRP and PPP at 1 hour and 48 hours after seeding. At the same time, the rate of different cells proliferation on the treated membranes at 48 hours was significant higher than those on the treated membranes at 1 hour. There was no significant differences in the same group for the rate of cells proliferation. Most of the cells attached on the membranes treated with PRP and PPP exhibited robust and elongated forms with numerous filopodial extensions. CONCLUSION: The results showed that the biodegradable membranes treated with PRP and PPP could promote rat cell attachment and proliferation. It suggests that this novel technique will provide the experimental basis for the development of cell delivery carriers and periodontal regeneration.

Animals↗
PubMed2006

Large-scale synthesis of single crystal silver nanowires by a sodium diphenylamine sulfonate reduction process.

Silver nanowires with high aspect ratios of up to more than 60 were synthesized on a large scale by the redox reaction between silver nitrate and sodium diphenylamine sulfonate at room temperature and in the absence of surfactant and hard-template and seed. When the molar ratio of reductant sodium diphenylamine sulfonate and silver nitrate < or =1, most products were all the nanowires. When the molar ratio increases to 2:1, silver nanowires and nanobelts were concomitantly formed. The redox product N, N'-diphenylbenzidinedisulfonate and sodium diphenylamine sulfonate all play an important role in the formation of silver nanostructures. The structure, morphology, and composition of the silver nanowires were characterized by the X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray energy dispersive microanalysis (EDX), and UV-Vis spectroscopy respectively. High-resolution transmission microscopy (HRTEM) and selected area electron diffraction (SAED) reveal the single-crystal nature of the silver nanowires.

Benzenesulfonates↗
PubMed2006

[Screening the hALR-interacting protein from the cDNA library of hepatocarcinoma cells and studying its biological functions].

OBJECTIVES: To screen the hALR-interacting protein by phage-displayed technique and identify its biological activities. METHODS: The specific phage clones that interacted with target protein hALR from a cDNA library of hepatocarcinoma cells were selected using the T7 phage-displayed technique. The acquired cDNA inserts were sequenced and analyzed by bioinformatic tools. The biological activities of the phage-displayed peptide affecting QGY hepatocarcinoma cells were studied using 3H-TdR method. RESULTS: The cDNA inserts with 212 bp were acquired after 4 rounds of biopanning. They showed 100% homology with citron kinase. The phage-displayed peptide and the peptide combined with hALR affected QGY cells proliferation. CONCLUSIONS: hALR-interacting peptide can be specifically screened by phage-displayed technique. Citron kinase that interacted with hALR potentially plays an important role in the proliferation of hepatocarcinoma cells.

Carcinoma, Hepatocellular↗
PubMed2006

[Inhibitory effect of blocking expression of human augmenter of liver regeneration (hALR) on proliferation of hepatocellular carcinoma cell line HepG2].

BACKGROUND & OBJECTIVE: Human augmenter of liver regeneration (hALR) is highly expressed in hepatocellular carcinoma (HCC), but rarely expressed in normal liver cells. ALR could stimulate the proliferation of HCC cell line in vitro, but has no effect on normal hepatocytes. This study was to investigate the inhibitory effect of blocking the expression of hALR on the proliferation of HCC cell line HepG2 using small interfering RNA (siRNA) targeting ALR and anti-ALR monoclonal antibody (McAb). METHODS: RNA interference (RNAi) plasmid pSIALR-A targeting hALR cDNA and control plasmid pSIALR-B were constructed and transfected into HepG2 cells, respectively. After transfection, the expression of green fluorescent protein was observed under a fluorescent microscope to calculate transfection efficiency, the protein level of hALR was measured by immunocytochemistry, meanwhile, the expression of hALR mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). (3)H-TdR incorporation approach was performed to detect the proliferation of HepG2 cells after transfection and after neutralization with anti-hALR McAb. RESULTS: hALR was expressed in HepG2 cells. Plasmids pSIALR-A and pSIALR-B were successfully constructed. Both immunocytochemistry and RT-PCR showed that pSIALR-A inhibited the expression of hALR in HepG2 cells significantly by 83% as compared with pSIALR-B. pSIALR-A specifically inhibited the growth of HepG2 cells after transfection. (3)H-TdR incorporation of pSIALR-A/HepG2 cells was significantly lower than that of pSIALR-B/HepG2 cells (67 687+/-6 548 vs. 104 807+/-5 713, P<0.05). Anti-hALR McAb markedly inhibited the autonomous growth of HepG2 cells (P<0.05). CONCLUSIONS: hALR is highly expressed in HepG2 cells. The short interfering RNA targeting hALR gene could specifically suppress the expression of hALR, and subsequently inhibit the growth of HepG2 cells. Anti-hALR McAb could partially inhibit the autonomous growth of HepG2 cells.

Antibodies, Monoclonal↗
PubMed2005

Combined effects of radiation and interleukin-13 receptor-targeted cytotoxin on glioblastoma cell lines.

PURPOSE: Interleukin-13 receptor-targeted cytotoxin (IL13-PE38) is highly cytotoxic to human glioblastoma (GBM) cells. Although this molecule is being tested in a multicenter Phase III clinical trial (PRECISE Study) in patients with recurrent disease, the activity of IL13-PE38 when combined with radiation therapy has not been investigated. METHODS AND MATERIALS: Cytotoxicity of IL13-PE38 to GBM cell lines was assessed by protein synthesis inhibition and clonogenic assays, and the growth of GBM cells receiving radiation was assessed by thymidine uptake assays. Expression of IL-13 receptor alpha2 (IL-13Ralpha2) messenger ribonucleic acid (mRNA) in GBM cells exposed to radiation was assessed by quantitative reverse transcriptase/polymerase chain reaction (RT-PCR) and IL-13R density by radiolabeled IL-13 binding assays. RESULTS: Prior irradiation of GBM cell lines followed by IL13-PE38 treatment did not enhance cytotoxicity; however, concomitant 5 Gy irradiation and IL13-PE38 treatment was highly cytotoxic to T98G, M059K, A172, and LN-229 cell lines as determined by cell viability assays. There was a statistically significant decrease in number of viable cells in IL13-PE38 and irradiated cells compared with irradiated cells alone (p < 0.05) or IL13-PE38 treated cells alone (p < 0.05). In contrast, U251, SN19, and U87MG cell lines did not show any combined effect. These results were confirmed by clonogenic assays. Although three GBM cell lines-U251, SN19, and A172-showed 2.8- to 13.9-fold upregulation of IL-13Ralpha2 mRNA expression at 6-24 h after exposure to 5 Gy radiation, specific binding of radiolabeled IL-13 to these cell lines did not improve. CONCLUSIONS: Our results suggest that concomitant radiation therapy and IL13-PE38 treatment may be beneficial for the treatment of patients with GBM. This strategy may be worth exploring in animal models of human glioma.

Bacterial Toxins↗