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Qian Dong

Publications and source records attributed to Qian Dong.

At least 19 recordsLinked to original sources
PubMed2026

Mendelian Randomization Analysis of NETs-Associated Inflammatory Traits and Type 2 Diabetes and its Complications.

Neutrophil extracellular traps (NETs) -associated inflammatory traits play a significant role in type 2 diabetes mellitus (T2DM) and its complications. Notably, IL-6, a key inflammatory cytokine, is intricately linked to the formation of NETs and the pathogenesis of T2DM and its complications. This study aimed to explore the causal association between NETs-associated inflammatory traits and T2DM, as well as its complications, using a Mendelian Randomization (MR) approach. This study utilized a two-sample MR design with data from Genome-Wide Association Studies (GWAS), comprising a large European population-based meta-analysis for T2DM and its complications. The primary method of analysis was the inverse variance weighted (IVW) approach, complemented by MR-Egger regression, weighted median, and weighted mode methods. Sensitivity analyses included MR-Egger, MR-PRESSO, Cochran's Q, and leave-one-out methods to assess the robustness of the findings. The study indicated that genetically predicted levels of interleukin-6 (IL-6) were inversely associated with diabetic coronary artery disease (CAD) (OR = 0.8997, 95% CI: 0.8257-0.9803, P = 0.0158). Additionally, NETs showed significant associations with T2DM with renal complications (OR=0.97, 95% CI 0.9428-0.998, P = 0.0358) and T2DM with peripheral circulatory complications(OR = 1.0342, 95% CI 1.002-1.0673, P = 0.037). The significant IVW associations showed no evidence of heterogeneity or horizontal pleiotropy. This study suggests that genetically predicted NETs-associated inflammatory traits are associated with specific T2DM complications. Genetically predicted IL-6 was inversely associated with diabetic CAD, whereas NETs were associated with renal and peripheral circulatory complications in T2DM.

Diabetes Mellitus, Type 2↗
PubMed2006

Management strategy for congenital choledochal cyst with co-existing intrahepatic dilation and aberrant bile duct as well as other complicated biliary anomalies.

The purpose of this study was to investigate and discuss imaging methods and management strategies for congenital choledochal cyst with co-existing intrahepatic dilation and aberrant bile duct as well as other complicated biliary anomalies. In this study we reviewed and analyzed 72 patients with congenital choledochal cyst, ranging in age from 15 days to 12 years old and who were seen at our hospital during the past 12 years, from January 1993 to October 2005. The image manifestation and clinical significance of patients with co- existing intrahepatic biliary dilation and aberrant bile duct were carefully examined during operation via MRCP, cholangiography and choledochoscope. Twenty-two cases (30.1%) presented with intrahepatic bile duct dilation and 12 of these were of the cystic type. That is, the orifice of the dilated intrahepatic tract that converged into the common hepatic duct showed membrane or septum-like stenosis. In 10 cases the dilation tapered off from the porta hepatis to the initiating terminals of the intra-hepatic bile ducts and was not accompanied by stenosis. An aberrant bile duct was observed in 2 of the cases. In 3 cases, the right and left hepatic ducts converged at the choledochal cyst. In conclusion, the imaging methods for intrahepatic bile duct dilation possess important clinical significance. Further, for hepatojejunostomy with radical excision of a choledochal cyst, additional operative procedures for intrahepatic stenosis, possible bile duct malformation and pancreaticobiliary common duct calculi can potentially reduce postoperative complications.

Bile Ducts↗
PubMed2005

Monovalent cations affect the free solution mobility of DNA by perturbing the hydrogen-bonded structure of water.

The free solution mobilities of single- and double-stranded DNA molecules of various molecular weights have been measured by capillary electrophoresis in solutions of constant ionic strength containing a common anion and fifteen different monovalent cations. In solutions with the same ionic composition, the mobilities of different DNA molecules can vary by up to 20%, depending on molecular weight, the number of strands, and the presence or absence of A-tracts, runs of four or more contiguous adenine residues. Importantly, the mobilities observed for the same DNA sample can vary by up to 40% in solutions containing different cations. The mobility differences observed for the same DNA in solutions containing different cations cannot be rationalized by differences in the anhydrous radii or intrinsic conductivities of the various cations, or by the sequence-dependent binding of certain cations to A-tracts. Instead, the observed mobilities are linearly correlated with the average number of water-water hydrogen bonds that are present in solutions containing different cations. The mobilities are also correlated with the viscosity B coefficients of the various cations and with the rotational correlation times frictional coefficients observed for water molecules in solutions containing different cations. Hence, monovalent cations modify the free solution mobility of DNA primarily by perturbing the hydrogen-bonded structure of water, affecting the friction experienced by the migrating DNA molecules during electrophoresis.

Base Sequence↗
PubMed2005

Functional diffusion map: a noninvasive MRI biomarker for early stratification of clinical brain tumor response.

Assessment of radiation and chemotherapy efficacy for brain cancer patients is traditionally accomplished by measuring changes in tumor size several months after therapy has been administered. The ability to use noninvasive imaging during the early stages of fractionated therapy to determine whether a particular treatment will be effective would provide an opportunity to optimize individual patient management and avoid unnecessary systemic toxicity, expense, and treatment delays. We investigated whether changes in the Brownian motion of water within tumor tissue as quantified by using diffusion MRI could be used as a biomarker for early prediction of treatment response in brain cancer patients. Twenty brain tumor patients were examined by standard and diffusion MRI before initiation of treatment. Additional images were acquired 3 weeks after initiation of chemo- and/or radiotherapy. Images were coregistered to pretreatment scans, and changes in tumor water diffusion values were calculated and displayed as a functional diffusion map (fDM) for correlation with clinical response. Of the 20 patients imaged during the course of therapy, 6 were classified as having a partial response, 6 as stable disease, and 8 as progressive disease. The fDMs were found to predict patient response at 3 weeks from the start of treatment, revealing that early changes in tumor diffusion values could be used as a prognostic indicator of subsequent volumetric tumor response. Overall, fDM analysis provided an early biomarker for predicting treatment response in brain tumor patients.

Adolescent↗
PubMed2005

Estimating the effects of informal radiology resident teaching on radiologist productivity: what is the cost of teaching?

RATIONALE AND OBJECTIVES: One mission of an academic radiology department is to teach. The greatest teaching effort is directed at radiology residents. As clinical work demands increase, informal, non-revenue-generating, teaching may suffer. We sought to determine the economic consequences of teaching. MATERIALS AND METHODS: With the use of a picture archiving and communications system, 6 radiology faculty members independently interpreted and dictated digitally acquired bone and chest radiographs for 1 hour alone and again 10-12 weeks later with a first-year resident. During the second session, the quality of teaching was graded by independent observers. The number of cases, relative value units (RVUs), and reimbursement for each session were calculated. RESULTS: The difference in number of cases dictated working alone (mean, 44.7) and with a first-year resident (mean, 23.5) was significant (P = 0.007). The difference between RVUs generated by faculty alone (mean, 9.0) and with a resident (mean, 4.5) also was significant (P = 0.006), and the difference in dollars billed when working alone (mean, $1558.45) and with a resident (mean, $777.65) was significant (P = 0.007). As teaching quality increased, the number of cases interpreted, dollars billed, and RVUs trended lower. CONCLUSION: Informal resident teaching significantly reduces clinical throughput, reducing examination volume, RVUs, and dollars billed by approximately half.

Bone and Bones↗
PubMed2005

[Correlation between expression of MMP-2, MMP-9, TIMP-2, TIMP-1 and metastasis of neuroblastoma].

OBJECTIVE: To study MMP-2, MMP-9, TIMP-2 and TIMP-1 expression, and their association to invasion and metastasis of neuroblastoma (NB). METHODS: The staining status was compared of MMP-2, MMP-9, TIMP-2 and TIMP-1 in cryostat sections of tumor tissue in 35 NB patients by immunohistochemistry. RESULTS: Strong expression of MMP-2 was detected only in 2 patients with early stage NB (group A without metastasis), but in 9 and 10 respectively with advanced stage NB (group B with local metastasis and group C with distant metastasis) (compared to group A, P < 0.01). Strong MMP-9 staining was found in 4, 8 and 11 patients for group A, B and C patients (group A vs group C, P < 0.05). The expression of TIMP-2 was the strongest in 4 group A patients, but it decreased with progression of the disease. There was no statistical difference in TIMP-1 expression among the three groups of patients. CONCLUSION: MMP-2, MMP-9 expression may be related to metastasis and progression of neuroblastoma, while TIMP-2 may have an inhibitory effect.

Child↗
PubMed2004

Clinical applications of diffusion tensor imaging.

Directionally-ordered cellular structures that impede water motion, such as cell membranes and myelin, result in water mobility that is also directionally-dependent. Diffusion tensor imaging characterizes this directional nature of water motion and thereby provides structural information that cannot be obtained by standard anatomic imaging. Quantitative apparent diffusion coefficients and fractional anisotropy have emerged from being primarily research tools to methods enabling valuable clinical applications. This review describes the clinical utility of diffusion tensor imaging, including the basic principles of the technique, acquisition, data analysis, and the major clinical applications.

Anisotropy↗
PubMed2004

Completion of colorectal cancer screening in women attending screening mammography.

RATIONALE AND OBJECTIVES: The American Cancer Society (ACS) and the United States Preventive Services Task Force (USPSTF) recommend colorectal cancer (CRC) screening to begin at age 50 in individuals at average risk for CRC. To estimate rate at which women eligible for CRC screening at the time of screening mammography attendance later completed in CRC screening, we retrospectively evaluated CRC screening utilization in women who underwent screening mammography at our institution. MATERIALS AND METHODS: We retrospectively identified 3357 women between the ages of 50 to 75 who received screening mammography in 1998 at a single academic medical center using the institution's Radiology Information System (RIS). Additional information collected from the institution's Health System Data Warehouse and the Radiology department's mammography quality assurance data included mammography results, Breast Imaging Reporting and Database System (BI-RADS) classification of mammography findings, recommendation for screening mammography follow-up, insurance status, and CRC screening utilization after screening mammography. After excluding women who were current with CRC screening at the time of mammography, we determined the proportion of eligible women who completed CRC screening after mammography. Age, insurance type, BI-RADS code, and recommendation code were evaluated as potential predictors of CRC screening completion in eligible women. RESULTS: Of the 3357 women between the ages of 50 and 75 who received screening mammography in 1998, only 414 (12.3%) were current with CRC screening at the time of screening mammography. Of the remaining 2943 women who were eligible for CRC screening at the time of screening mammography, 142 (4.8%) subsequently completed CRC screening. Average time to completion of CRC screening after screening mammography is 35.4 months (range, 0.27-64.9). Managed care insurance was the only significant predictor of CRC screening completion after screening mammography in eligible women after adjusting for other variables (adjusted OR 1.73, 95% CI 1.21-2.47, P < .0001). Neither BI-RADS classification nor postmammography recommendations were significantly associated with CRC screening completion. CONCLUSIONS: Prevalence studies have demonstrated that women who were compliant with screening mammography were more compliant with CRC screening. Our data suggest that despite this increased compliance, overall incidence of CRC screening is low in the screening mammography population.

Aged↗
PubMed2003

Free solution mobility of small single-stranded oligonucleotides with variable charge densities.

The free solution mobilities of six single-stranded 16-nucleotide DNA oligomers with the same sequence, containing up to 11 neutral phosphoramidate internucleoside linkages, have been measured by capillary electrophoresis. The mobilities of the partially charged oligomers increase linearly with the logarithm of increasing charge density, as predicted by the Manning theory of electrophoresis (G. S. Manning, J. Phys. Chem. 1981, 85, 1506-1515). For comparison, the mobilities of eight fully charged single-stranded oligomers containing similar numbers of charged phosphate residues have also been measured. The mobilities of the variable length, fully charged oligomers increase more rapidly with the increasing number of charged phosphate residues than the mobilities of the constant size, partially charged phosphoramidate derivatives, because of the larger diffusion coefficients of the modified oligomers.

Amides↗
PubMed2003

Evaluation of cancer therapy using diffusion magnetic resonance imaging.

Assessment of the effectiveness of cancer therapy traditionally relies on comparison of tumor images acquired before and after therapeutic intervention by inspection of gross anatomical images to evaluate changes in tumor size. The potential for imaging to provide additional insights related to the therapeutic impact would be enhanced if a specific parameter or combination of parameters could be identified that reflect tissue changes at the cellular or physiological level. This information could also provide a more sensitive and earlier indicator of treatment response in an individual animal or patient. Diffusion magnetic resonance imaging can detect relatively small changes in tissue structure at the cellular level and thus provides an opportunity to quantitatively and serially follow therapeutic-induced changes in solid tumors. This article provides an overview of the use of diffusion magnetic resonance imaging as a surrogate marker for quantitating treatment responsiveness in both preclinical and clinical studies.

Animals↗
PubMed2002

Direct amperometric determination of lactate at a carbon fiber bundle microdisk electrode by capillary zone electrophoresis.

Capillary zone electrophoresis was employed for the determination of lactate using end-column amperometric detection at a carbon fiber bundle microdisk electrode. The optimum conditions of separation and detection are 3.6 x 10(-3) mol/l Na(2)HPO(4)-1.4 x 10(-3) mol/l NaH(2)PO (pH 7.2) for the buffer solution, 18 kV for the separation voltage and 1.60 V versus the saturated calomel electrode for the detection potential. The limit of detection is 7.6 x 10(-7) mol/l or 1.7 fmol (S/N=3) and the linear range is 1.7 x 10(-6)-8.2 x 10(-4) mol/l for the injection voltage of 6 kV and injection time of 5 s. The RSD is 1.8% for the migration time and 3.3% for the electrophoretic peak current. The method was applied to the determination of lactate in human saliva. The recovery of the method is between 95 and 109%.

Carbon↗
PubMed2002

Method of intracellular naphthalene-2,3-dicarboxaldehyde derivatization for analysis of amino acids in a single erythrocyte by capillary zone electrophoresis with electrochemical detection.

A novel method of intracellular derivatization was developed. In this method, the derivatization reagents [naphthalene-2,3-dicarboxaldehyde (NDA) and CN-] were introduced into living cells by electroporation for the derivatization reaction. After completion of derivatization reaction in cells, a single cell was drawn into the capillary tip by electroosmotic flow. Then the lysing solution was introduced into the capillary by diffusion. Once the individual cell was lysed, the derivatized amino acids in the individual cell were separated by capillary zone electrophoresis and detected by end-column amperometric detection at the outlet of the capillary. This method of intracellular NDA derivatization confined the analytes and the derivatization reagents to the volume of a single cell expanded. For an 8-microm erythrocyte, the contents were diluted by a factor of only ca. 1.6. The method was used to determination of amino acids in single erythrocytes. Six amino acids were identified and quantified.

Amino Acids↗
PubMed2002

Analysis of amino acids by capillary zone electrophoresis with electrochemical detection.

The precapillary derivatization of 20 amino acids with naphthalene-2,3-dicarboxaldehyde (NDA) and CN(-) was investigated. All these derivatized amino acids could be oxidized on the carbon fiber microdisk bundle electrode except proline. Capillary zone electrophoresis with electrochemical detection was employed for the analysis of 19 amino acids. The optimum conditions of separation and detection were borate, pH 9.48, for the electrolyte, 18 kV for the separation voltage and 1.15 V versus a saturated calomel electrode for the detection potential. Limits of detection of concentration or mass for individual amino acids were between 1.7 x 10(-7) and 1.8 x 10(-6) mol/L or 84 and 893 amol (according to the signal-to-noise ratio of 3) for the injection voltage of 6 kV and injection time of 10 s. The relative standard deviations were between 0.80 and 2.3% for the migration times and 1.4 and 6.4% for the electrophoretic peak currents. From a mixture of 19 amino acids, 10 amino acids (Arg, Lys, Orn, Try, Ser, Ala, Gly, Cys, Glu, Asp) could be well separated. The other 9 amino acids appeared on three electrophoretic peaks. From the samples, in which the nine amino acids do not exist simultaneously, some of them could also be detected. The method was applied to the determination of amino acids in beer by the standard addition method. The recovery for the amino acids in beer was 91-109%.

Amino Acids↗
PubMed2002

Biliary imaging with Gd-EOB-DTPA: is a 20-minute delay sufficient?

RATIONALE AND OBJECTIVES: The authors performed this study to quantitate the change in intrabiliary signal intensity 20 minutes after gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) injection and to correlate the degree of biliary visualization with changes in biliary signal intensity. MATERIALS AND METHODS: Sixteen patients with known hepatic masses (without known biliary disease) who were candidates for resection were enrolled in an open-label protocol of Gd-EOB-DTPA. Three-dimensional spoiled gradient-echo magnetic resonance (MR) images obtained in the coronal plane with breath holding before and 20 minutes after Gd-EOB-DTPA made up the biliary MR cholangiogram study. Manually defined regions of interest were used to measure signal intensity in the bile ducts before and after contrast material administration. Signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were calculated. Biliary visualization was qualitatively assessed by using a five-point scale. RESULTS: The SNR and CNR significantly increased (P < .0002) after the administration of contrast material. Average biliary visualization ratings were excellent, with moderate to excellent interobserver agreement. There was no correlation between measured SNR or CNR and visualization ratings. CONCLUSION: A 20-minute delay after Gd-EOB-DTPA administration appears to be sufficient for adequate biliary enhancement. Residual hepatic enhancement does not appear to interfere with biliary visualization.

Adult↗
PubMed2002

Diffusion MRI: a new strategy for assessment of cancer therapeutic efficacy.

The use of anatomical imaging in clinical oncology practice traditionally relies on comparison of patient scans acquired before and following completion of therapeutic intervention. Therapeutic success is typically determined from inspection of gross anatomical images to assess changes in tumor size. Imaging could provide significant additional insight into therapeutic impact if a specific parameter or combination of parameters could be identified which reflect tissue changes at the cellular or physiologic level. This would provide an early indicator or treatment response/outcome in an individual patient before completion of therapy. Moreover, response of a tumor to therapeutic intervention may be heterogeneous. The use of imaging could assist in delineating therapeutic-induced spatial heterogeneity within a tumor mass by providing information related to specific regions that are resistant or responsive to treatment. Largely untapped potential resides in exploratory methods such as diffusion MRI, which is a nonvolumetric intravoxel measure of tumor response based upon water molecular mobility. Alterations in water mobility reflect changes in tissue structure at the cellular level. While the clinical utility of diffusion MRI for oncologic practice is still under active investigation, this overview on the use of diffusion MRI for the evaluation of brain tumors will serve to introduce how this approach may be applied in the future for the management of patients with solid tumors.

Brain Neoplasms↗