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Qiang Li

Publications and source records attributed to Qiang Li.

258 records · Page 15Linked to original sources
PubMedDate not supplied

Inhibition of polycystin-L channel by the Chinese herb Sparganum stoloniferum Buch.-Ham.

The Chinese herb Sparganum stoloniferum Buch.-Ham. (SBH) is frequently used to improve blood circulation and to rehabilitate vascular obstruction in traditional Chinese medicine. It was recently reported that SBH reduces the proliferation of renal epithelial cells stimulated by epidermal growth factor (EGF), and inhibits the phosphorylation of the EGF receptor. SBH has also been used as a trial drug to treat polycystic kidney disease (PKD) patients in China. The potential molecular actions of SBH on PKD remain unknown. Autosomal dominant PKD (ADPKD) is associated with mutations in polycystin-1 or polycystin-2 (PC2). PC2 and its homologue, polycystin-L (PCL), are nonselective cation channels permeable to potassium, sodium, and calcium. Here, we examine the effects of SBH on the human PCL channel expressed in Xenopus oocytes, using 2-microelectrode voltage-clamp electrophysiology and radiotracer uptake measurements. In PCL-expressing oocytes, with or without preincubation with SBH, the PCL channel was inhibited by SBH in a dose-dependent and reversible manner; a concentration of 2% SBH completely abolished the channel activation. The IC50 value for SBH was 0.48% +/- 0.03%, with a 10-min preincubation period. SBH was also found to inhibit the PCL-mediated 45Ca tracer uptake in oocytes. Our study suggests that SBH contains 1 or more yet-to-be determined components that are inhibitors of PCL channel. The therapeutic potential of SBH for ADPKD and its chemical composition remain to be investigated.

Animals↗
PubMedDate not supplied

Computer-aided diagnosis in chest radiography: results of large-scale observer tests at the 1996-2001 RSNA scientific assemblies.

Since 1996, computer-aided diagnosis (CAD) schemes have been presented as interactive demonstrations on computer workstations at each scientific assembly of the Radiological Society of North America. The schemes involved (a) detection of pulmonary nodules, (b) temporal subtraction, (c) detection of interstitial lung disease, (d) differential diagnosis of interstitial lung disease, and (e) distinction between benign and malignant pulmonary nodules on chest radiographs. Large-scale observer tests were carried out to examine how radiologists can benefit from CAD systems. Observer performance was evaluated by analysis of receiver operating characteristic (ROC) curves. The statistical significance of the difference between the areas under the ROC curves without and with CAD was analyzed with the Student t test. In all of the tests, the diagnostic accuracy of the radiologists in total improved significantly when CAD was used. This result provides additional evidence that CAD has the potential to improve the performance of radiologists in their decision-making process in interpreting chest radiographs.

Diagnosis, Computer-Assisted↗
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State and community tobacco-control programs and smoking-cessation rates among adult smokers: what can we learn from the COMMIT intervention cohort?

PURPOSE: To assess the long-term effect of a randomized community-based trial of smoking cessation and to examine the effect of exposure to large state-based tobacco-control programs on smoking cessation. DESIGN: Longitudinal tobacco-use telephone surveys conducted in 1988, 1993, and 2001. SETTING AND PARTICIPANTS: Baseline smokers (6603) from 20 communities in 9 states completed a survey in 2001 (35% of the original sample). INTERVENTION: The Community Intervention Trial for Smoking Cessation (COMMIT) intervention was a randomized community-based smoking-cessation intervention between 1988 and 1993. In addition, cohort data were used to evaluate quasi-experimental differences in the strength of state-level tobacco control programs and policies. MEASURES: Multivariate logistic regression was used to compare quit rates among those who were exposed to community- or state-level tobacco-control programming and those who were not between 1988 and 2001. RESULTS: Quit rates were higher in the COMMIT intervention communities during the period when the trial was funded (Relative Risk [RR] = 1.19) but were no different than comparison communities 8 years later after funding stopped. Quit rates were highest in those communities in states with both strong tobacco-control policies and aggressive tobacco-control programs, such as California and Massachusetts (RR = 1.44) compared with those communities in states that had little tobacco-control activity, such as Iowa, New Mexico, and North Carolina. CONCLUSIONS: The findings suggest that well-funded tobacco-control programming coupled with tobacco-control policies may be associated with increases in cessation rates.

Adult↗
PubMedDate not supplied

Prognostic significance of expression of p53 oncoprotein in primary (stage I-IIIa) non-small cell lung cancer.

Mutation of the p53 gene is one of the most common genetic abnormalities found in all types of human cancer. Accumulating evidence strongly indicates that p53 alterations play a role in tumorgenesis in non-small cell lung cancer (NSCLC). However, the role of p53 as a prognostic marker in NSCLC remains unclear. The data derived from the literature on prognostic impact of p53 in NSCLC has been a matter of controversy. Among the reasons for the discrepancy, are lack of correlation with key clinical parameters, patients with different stages, different antibodies used, and insufficient sample size. The intent of this study was to evaluate the prognostic value of p53 protein in a larger cohort of stage I-IIIa patients. Clinicopathological data was obtained on 179 patients with NSCLC. These data were correlated with the p53 status on the respective surgically resected tumors, using monoclonal antibody DO7. There is a significant relationship between strong p53 expression and patient survival. In a multivariate analysis, strong expression (> 50%) of the p53 oncoprotein is an independently favorable prognostic factor. Patients with strong p53 expression had a prolonged survival (p = 0.009, RR; 0.56, 95% CI: 0.35-0.86). The median time of survival for patients with strong and negative/weak p53 expression was more than 61 and 44 months, respectively. The present study suggests that p53 protein expression in tumor tissue may serve as a prognostic biomarker for NSCLC. This information may also potentially serve as a tool for clinical decision-making when selecting patients for adjuvant treatments of NSCLC.

Adult↗