Biomedical subjects

Bing Qi

Publications and source records attributed to Bing Qi.

At least 19 recordsLinked to original sources

PubMed2026

Causal effect of chloride intracellular channel protein 5 on chronic periodontitis: A Mendelian randomization study.

This study aimed to evaluate the potential causal effect of chloride intracellular channel protein 5 (CLIC5) on the risk of chronic periodontitis (CP) using a Mendelian randomization (MR) approach. MR analysis was conducted utilizing publicly available summary statistics from genome-wide association studies summary statistics for CLIC5 and CP. Multiple MR methods, including inverse variance weighted, MR Egger, weighted median and weighted mode, were employed to estimate the causal effects. Sensitivity analyses, comprising leave-one-out and heterogeneity assessments were performed to evaluate the robustness of our findings. This MR analysis consistently revealed a negative association between CLIC5 and CP, with statistical significance achieved using the inverse variance weighted and weighted median methods. The concordant effect estimates obtained from all methodological approaches collectively indicated a potential protective effect of CLIC5 against CP. The sensitivity analyses further confirmed the robustness of these findings. This study provides genetic evidence suggesting a potential causal association between increased CLIC5 levels and decreased risk of CP. These findings augment the existing literature implicating chloride channel proteins in modulating the inflammatory processes pertinent to periodontal health. Further investigation is warranted to decipher the underlying biological mechanisms and to explore the potential of CLIC5 as a therapeutic target for CP.

Chloride Channels↗

PubMed2006

Single-photon continuous-variable quantum key distribution based on the energy-time uncertainty relation.

We propose a new quantum key distribution protocol in which information is encoded on continuous variables of a single photon. In this protocol, Alice randomly encodes her information on either the central frequency of a narrowband single-photon pulse or the time delay of a broadband single-photon pulse, while Bob randomly chooses to do either frequency measurement or time measurement. The security of this protocol rests on the energy-time uncertainty relation, which prevents Eve from simultaneously determining both frequency and time information with arbitrarily high resolution. Since no interferometer is employed in this scheme, it is more robust against various channel noises, such as polarization and phase fluctuations.

Journal Article↗

PubMed2006

Experimental quantum key distribution with decoy states.

To increase dramatically the distance and the secure key generation rate of quantum key distribution (QKD), the idea of quantum decoys--signals of different intensities--has recently been proposed. Here, we present the first experimental implementation of decoy state QKD. By making simple modifications to a commercial quantum key distribution system, we show that a secure key generation rate of 165 bit/s, which is 1/4 of the theoretical limit, can be obtained over 15 km of a telecommunication fiber. We also show that with the same experimental parameters, not even a single bit of secure key can be extracted with a non-decoy-state protocol. Compared to building single photon sources, decoy state QKD is a much simpler method for increasing the distance and key generation rate of unconditionally secure QKD.

Journal Article↗

PubMed2006

Performance of low pH biofilters treating a paint solvent mixture: continuous and intermittent loading.

Two biofilters packed with a reticulated polyurethane foam medium were inoculated with a compost-derived enrichment culture grown under acidic conditions (pH 3.0) and then operated over a period lasting 63 days. Both biofilters were supplied with a humidified gas stream containing a five-component mixture of acetone, methyl ethyl ketone, toluene, ethylbenzene, and p-xylene at a total VOC loading rate 80.3 gm(-3)h(-1) to simulate treatment of air emissions resulting from manufacture of reformulated paint. One biofilter was operated under continuous loading conditions and the other received intermittent loading with contaminants supplied only 8 h/day. Nutrient solution with pH 3.0 was supplied approximately once per week to provide nitrogen and other nutrients. Data are presented which demonstrate that undefined mixed cultures acclimated at low pH can successfully treat paint solvent mixtures in biofilters. The biofilter receiving continuous loading reached high overall removal efficiency (greater than 90% overall removal) 3 weeks after startup, and performance increased over time reaching overall removal in the range of 97-99% after 50 days. Performance of the intermittently loaded biofilter developed more slowly, requiring 6 weeks to stabilize at an overall removal efficiency in excess of 90%. In both biofilters, ketone components were more rapidly degraded than aromatic components, and removal of aromatic compounds was somewhat unstable even after 2 months of biofilter operation. Scanning electron microscopy (SEM) revealed that fungi dominated the microbial populations in both biofilters.

Bioreactors↗

PubMed2006

[Application of multi-slice spiral CT in the diagnosis of pulmonary hypertension].

OBJECTIVE: To evaluate the utility of multi-slice spiral CT in the diagnosis of pulmonary hypertension. METHODS: The clinical and multi-slice spiral CT data of 22 patients with pulmonary hypertension were retrospectively analyzed. The diagnoses included chronic thromboembolic pulmonary hypertension (CTEPH) (n = 9), primary pulmonary hypertension (PPH) (n = 7), connective tissue diseases (n = 2), portal-pulmonary hypertension (n = 2), eosinophilia-myalgia syndrome (n = 1), and fibrosing mediastinitis (n = 1). Lung parenchyma, such as ground-glass opacity, mosaic attenuation and septal thickness, mediastinum, pulmonary vascular, right ventricular enlargement and interventricular septum displacement were evaluated on CT. RESULTS: CT pulmonary angiography (CTPA) accurately diagnosed 95% of pulmonary hypertension and the signs of right ventricular dysfunction. Pulmonary embolism was found in 9 patients. The incidence of mosaic attenuation was significantly higher in CTECH than in PPH (P = 0.034). CONCLUSION: CTPA can accurately diagnose pulmonary hypertension and thereby provide useful information for the etiological diagnosis.

Adult↗

PubMed2006

[Porcine follistatin cDNA cloning and expression in Escherichia coli].

The total RNA was extracted from porcine ovary. Porcine Follistatin cDNA was cloned by RT-PCR. Complete porcine follistatin cDNA coding sequences are presented including 1038 bp of open reading frame. The purified porcine follistatin cDNA was inserted into pGEX-4T-3 vector to construct the prokaryotic fusion protein expression vector. The recombinant expression plasmid was transformed into BL21 (DE3) and expression was induced by IPTG. Protein products were detected by SDS-PAGE and confirmed by Western blotting analysis, which showed that the yield of the Follistatin cDNA was a 63kD protein expression vector. Follistatin protein was expressed in the form of glutathione-S-transferase (GST) fusion protein in E. coli.

Amino Acid Sequence↗

PubMed2005

High-resolution, large dynamic range fiber length measurement based on a frequency-shifted asymmetric Sagnac interferometer.

We propose and experimentally demonstrate a single-mode fiber length and dispersion measurement system based on what we believe to be a novel frequency-shifted asymmetric Sagnac interferometer incorporating an acousto-optic modulator (AOM). By sweeping the driving frequency of the AOM, which is asymmetrically placed in the Sagnac loop, the optical length of the fiber can be determined by measuring the corresponding variation in the phase delay between the two counterpropagating light beams. Combined with a high-resolution data processing algorithm, this system yields a dynamic range from a few centimeters to 60 km (limited by our availability of long fibers) with a resolution of approximately 1 part per million for long fibers.

Journal Article↗

PubMed2005

P66shc regulates endothelial NO production and endothelium-dependent vasorelaxation: implications for age-associated vascular dysfunction.

The p66shc adaptor protein mediates age-associated oxidative stress. We examined the role of p66shc in endothelial nitric oxide synthase (eNOS) signaling. Overexpression of p66shc inhibited eNOS-dependent NO production. RNAi-mediated down-regulation of endogenous p66shc led to activation of the proto-oncogene ras, and Akt kinase, with a corresponding increase in phosphorylation of eNOS at S1177 (S1179 on bovine eNOS). In rat aortic rings, down-regulation of p66shc suppressed the vasoconstrictor response to phenyephrine that was abrogated by treatment with the NOS inhibitor l-NAME, and enhanced vasodilation induced by sub-maximal doses of acetylcholine. These findings highlight a pivotal role for p66shc in inhibiting endothelial NO production, and endothelium-dependent vasorelaxation, that may provide important mechanistic information about endothelial dysfunction seen with aging.

Acetylcholine↗

PubMed2005

Endoscopic Doppler optical coherence tomography in the human GI tract: initial experience.

BACKGROUND: Expanding the current endoscopic optical coherence tomography (OCT) system with Doppler capability may augment this novel high-resolution cross-sectional imaging technique with functional blood flow information. The aim of this feasibility study was to assess the clinical feasibility of an endoscopic Doppler OCT (EDOCT) system in the human GI tract. METHODS: During routine endoscopy, 22 patients were imaged by using a prototype EDOCT system, which provided color-Doppler and velocity-variance images of mucosal and submucosal blood flow at one frame per second, simultaneously with high-spatial-resolution (10-25 mum) images of tissue microstructure. The images were acquired from normal GI tract and pathologic tissues. OBSERVATIONS: Subsurface microstructure and microcirculation images of normal and pathologic GI tissues, including Barrett's esophagus, esophageal varices, portal hypertensive gastropathy, gastric antral vascular ectasia, gastric lymphoma, and duodenal adenocarcinoma, were obtained from 72 individual sites in vivo. Differences in vessel diameter, distribution, density, and blood-flow velocity were observed among the GI tissue pathologies imaged. CONCLUSIONS: To our knowledge, this is the first study to demonstrate the feasibility of EDOCT imaging in the human GI tract during routine endoscopy procedures. EDOCT may detect the different microcirculation patterns exhibited by normal and diseased tissues, which may be useful for diagnostic imaging and treatment monitoring.

Adult↗

PubMed2005

Biofilter treatment of volatile organic compound emissions from reformulated paint: complex mixtures, intermittent operation, and startup.

Two biofilters were operated to treat a waste gas stream intended to simulate off-gases generated during the manufacture of reformulated paint. The model waste gas stream consisted of a five-component solvent mixture containing acetone (450 ppm(v)), methyl ethyl ketone (12 ppm(v)), toluene (29 ppm(v)), ethylbenzene (10 ppm(v)), and p-xylene (10 ppm(v)). The two biofilters, identical in construction and packed with a polyurethane foam support medium, were inoculated with an enrichment culture derived from compost and then subjected to different loading conditions during the startup phase of operation. One biofilter was subjected to intermittent loading conditions with contaminants supplied only 8 hr/day to simulate loading conditions expected at facilities where manufacturing operations are discontinuous. The other biofilter was subjected to continuous contaminant loading during the initial start period, and then was switched to intermittent loading conditions. Experimental results demonstrate that both startup strategies can ultimately achieve high contaminant removal efficiency (>99%) at a target contaminant mass loading rate of 80.3 g m(-3) hr(-1) and an empty bed residence time of 59 sec. The biofilter subjected to intermittent loading conditions at startup, however, took considerably longer to reach high performance. In both biofilters, ketone components (acetone and methyl ethyl ketone) were, more rapidly degraded than aromatic hydrocarbons (toluene, ethylbenzene, and p-xylene). Scanning electron microscopy and plate count data revealed that fungi, as well as bacteria, populated the biofilters.

Air Pollution↗

PubMed2005

[The expression of hTERT and p53 protein in pre-malignant and malignant lesions of human oral mucosa].

PURPOSE: To investigate the roles of hTERT and p53 protein in malignant changes of oral mucosal precancerous lesions and the relations between hTERT and p53. METHODS: The expression of hTERTmRNA and p53 were measured using in situ hybridization and immunohistochemical assay in 9 cases of oral mucosal hyperplasia, 11 cases of light dysplasia, 10 cases of medium dysplasia, 9 cases of carcinomas in situ and 11 cases of squamous cell carcinomas. The results were processed by medical photographic system, and analyzed statistically by one-way ANOVA. The relation to hTERT and p53 was analyzed statistically by Pearson correlations. RESULTS: It was found that from hyperplasia to light dysplasia, medium dysplasia, carcinomas in situ and squamous cell carcinomas, the indexes of positive cell vessels and the value of OD increased, arriving at the apex in squamous cell carcinoma. With phenotypic progression and the degree of dysplasia, hTERT and p53 expression cells extend from basal layer to the keratinous layer. In highly-differentiated squamous cell carcinomas, expression cells were mainly located around the nests. Stained cells dispersed throughout the tumor tissue in low-differentiated squamous cell carcinomas. p53 was undetectable in hyperplasia and light dysplasia, but p53 was observed in 66.67% cases of high dysplasia and 72.72% cases of squamous cell carcinomas. There was not a significant linear correlation between hTERT and p53. CONCLUSIONS: The results suggest that activation of telomerase and p53 play a role in the process of malignant changes of oral mucosal precancerous lesions. Oral squamous cell carcinoma is a disease that has been found in association with many factors.

Carcinoma in Situ↗

PubMed2004

Mitochondrial fission proteins regulate programmed cell death in yeast.

The possibility that single-cell organisms undergo programmed cell death has been questioned in part because they lack several key components of the mammalian cell death machinery. However, yeast encode a homolog of human Drp1, a mitochondrial fission protein that was shown previously to promote mammalian cell death and the excessive mitochondrial fragmentation characteristic of apoptotic mammalian cells. In support of a primordial origin of programmed cell death involving mitochondria, we found that the Saccharomyces cerevisiae homolog of human Drp1, Dnm1, promotes mitochondrial fragmentation/degradation and cell death following treatment with several death stimuli. Two Dnm1-interacting factors also regulate yeast cell death. The WD40 repeat protein Mdv1/Net2 promotes cell death, consistent with its role in mitochondrial fission. In contrast to its fission function in healthy cells, Fis1 unexpectedly inhibits Dnm1-mediated mitochondrial fission and cysteine protease-dependent cell death in yeast. Furthermore, the ability of yeast Fis1 to inhibit mitochondrial fission and cell death can be functionally replaced by human Bcl-2 and Bcl-xL. Together, these findings indicate that yeast and mammalian cells have a conserved programmed death pathway regulated by a common molecular component, Drp1/Dnm1, that is inhibited by a Bcl-2-like function.

Adaptor Proteins, Signal Transducing↗

PubMed2004

Apurinic/apyrimidinic endonuclease 1 regulates endothelial NO production and vascular tone.

The dual-function protein apurinic/apyrimidinic endonuclease/redox factor-1 (APE1/ref-1) is essential for DNA repair and also governs the reductive activation of many redox-sensitive transcription factors. We examined the role of APE1/ref-1 in regulation of endothelium-dependent tone and systemic blood pressure. APE1/ref-1+/- mice have impaired endothelium-dependent vasorelaxation, reduced vascular NO levels, and are hypertensive. APE1/ref-1 upregulates H-ras expression and leads to H-ras-mediated, phosphoinositide-3 kinase/Akt kinase-dependent calcium sensitization of endothelial NO synthase (eNOS), stimulating NO production. The reducing property of APE1/ref-1 is essential for upregulation of H-ras and for the calcium sensitization of eNOS. These findings uncover a novel physiological role for APE1/ref-1 in regulating vascular tone by governance of eNOS activity and bioavailable NO.

Animals↗

PubMed2004

Self-compensating fiber optic flow sensor system and its field applications.

A self-compensating fiber optic flow sensor system based on the principle of broadband white-light interferometers and cantilever beam bending is described. The fiber optic sensor system uses two fiber ferrule sensors that are bonded on either side of a cantilever beam to measure the flow rate by monitoring the air-gap changes caused by the bending of the cantilever beam. Cross sensitivity of the temperature and pressure dependence of the sensor can be compensated for automatically. The prototype sensor system was constructed, laboratory characterized, and field tested. The results from the field testing have demonstrated high resolution, repeatability, and stability for on-line detection of the flow rates of fluids.

Journal Article↗

PubMed2004

Performance of a fungal biofilter treating gas-phase solvent mixtures during intermittent loading.

Biological treatment processes used to remove and degrade volatile organic compounds (VOCs) from contaminated gases emitted by industrial operations or waste treatment processes are almost always subjected to transient loading conditions because of the inherently unsteady-state nature of contaminant generating processes. In the study presented here, a laboratory-scale biofilter populated by a mixed culture of fungi was used to study the transient response to various periods of no contaminant loading in a system treating a model waste gas stream containing a mixture of commonly used solvents. The biofilter, packed with cubed polyurethane foam media and operated with an empty bed residence time of 15s, was supplied with a four-component mixture of n-butyl acetate, methyl ethyl ketone, methyl propyl ketone, and toluene at target influent concentrations of 124, 50.5, 174, and 44.6 mg/m(3), respectively. This corresponds to a total VOC loading rate of 94.3g/(m(3)h). Biofilter performance was evaluated over a 94-day period for three loading conditions intended to simulate processes generating contaminated gases only during daytime operation, daytime operation with weekend shutdown periods, and with long term (9-day) shutdown. Results indicate that fungal biofilters can be an effective alternative to conventional abatement technologies for treating solvent contaminated off-gases even under discontinuous loading conditions.

Acetates↗

PubMed2004

[Techniques and clinical applications of 16 multislice helical CT in colonic diseases].

OBJECTIVE: To evaluate the techniques and clinical applications of 16 multislice helical CT in colonic lesions. METHODS: Eighty-one patients including 54 colorectal carcinomas, 5 adenomas, 1 non-Hodgkin's lymphoma, 6 inflammatory bowel diseases, and other 15 cases underwent volume scanning using 16 multislice helical CT. Four types of reconstruction included multiple planar reconstruction, shaded surface display, raysum, and CT virtual colonoscopy. RESULTS: Complete colon could be shown in all patients. The lesions' morphology, number, size, location, intestinal cavity, pericolonic changes, and other abdominal organs were satisfactorily shown by CT. CONCLUSIONS: Sixteen multislice helical CT colonography is a valuable imaging technique for detecting colonic diseases. It is effective in diagnosis and treatment planning. It can display the portions of colon that is inaccessible at colonoscopy.

Adenocarcinoma↗

PubMed2004

[An experimental study on PLGA carrier for oral tissue engineered mucosa by subcutaneous implantation in rabbits].

OBJECTIVE: To look for the best carrier for cultivating oral tissue engineered mucosa. METHODS: A series of membrane of scaffold materials of polycleclide-co-plycoclide (PLGA) were studied on their weight and biocompatibility after they had been implanted subcutaneously in rabbits for 1, 2, 3, 4 weeks respectively. RESULTS: PLGA I , II, III degraded completely in rabbits after 2, 3, 4 weeks respectively. The other PLGA membrane degraded about 50% after 4 weeks. Histologically, the reactions of PLGA I, II, III with surrounding tissues were normal and membranes had a good biocompatibility. CONCLUSION: The biodegrading rate of PLGA II is suitable for clinic practice. PLGA II was a promising carrier for oral tissue-engineered mucosa due to its excellent biocompatibility and biodegrading rate.

Absorbable Implants↗

PubMed2003

Constitutive activation of rac1 results in mitochondrial oxidative stress and induces premature endothelial cell senescence.

OBJECTIVE: Oxidative stress has been implicated in cellular senescence and vascular aging. We determined the role and mechanism of the small GTPase rac1 in vascular endothelial cell senescence. METHODS AND RESULTS: Adenoviral-mediated expression of the constitutively active allele of rac1 (rac1V12) in human umbilical vein endothelial cells resulted in mitochondrial oxidative stress with induction of biochemical, molecular, and morphological features of senescence. Suppression of mitochondrial oxidative stress abrogated rac1-induced premature senescence. Rac1V12 expression also resulted in an increase in endothelial ceramide levels. Moreover, premature endothelial cell senescence induced by an exogenous cell-permeable ceramide analog was not suppressed by inhibiting endogenous rac1 signaling. Finally, in human umbilical vein endothelial cells that had undergone replicative senescence, rac1 was not activated, and expression of the dominant-negative rac1 allele (rac1N17) did not suppress mitochondrial oxidative stress. CONCLUSIONS: These findings paint a picture in which the constitutive activation of rac1, via the generation of ceramide, results in mitochondrial oxidative stress and premature endothelial cell senescence. However, they speak against a role for endogenous rac1 activation in the induction of mitochondrial oxidative stress associated with replicative senescence of endothelial cells.

Aging, Premature↗