[The combined use of artemether, sulfadoxine, pyrimethamine and primaquine in the treatment of chloroquine-resistant falciparum malaria].
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
X Zhan
Publications and source records attributed to X Zhan.
Effect of iodinated contrast media on neutrophil adhesion to cultured endothelial cells.
PURPOSE: To investigate the influence of contrast media (CM) on endothelial cells (ECs) with respect to cytotoxicity and to neutrophil adhesion. MATERIALS AND METHODS: Human umbilical vein ECs were incubated with chromium-51-labeled human neutrophils in the presence of CM (diatrizoate, ioxaglate, iopamidol, and iodixanol) in three concentrations: 2, 20, and 50 mg I/mL. CM was compared with glucose solutions prepared from plain, buffered glucose solutions, iso-osmolar to the corresponding CM solution. Neutrophil adhesion to the EC monolayer, EC morphology, and cytotoxicity were evaluated. RESULTS: The effect of CM on neutrophil adhesion was dependent on dose, with increased adhesion at low CM concentrations (2 and 20 mg I/mL) and decreased adhesion at high CM concentration (50 mg I/mL). The response was observed only if ECs and neutrophils were exposed to CM simultaneously in a shared environment. Glucose solutions with the same osmolarity did not show similar effect. Both diatrizoate and ioxaglate had a greater cytotoxic effect on ECs and neutrophils than did iodixanol and iopamidol. CONCLUSION: The altered neutrophil adhesion to ECs may be due to CM-induced cytotoxicity or CM-induced EC activation because the glucose solutions did not cause a similar change at equal osmolality. The lack of cell death, combined with altered neutrophil adhesion implies modulation of cell adhesion molecules by CM. The results could be pertinent to the pathogenesis of peripheral vascular lesions and the endothelial response in immunosuppressed or septic patients receiving CM during imaging studies.
Cell Adhesion↗
Facilitating the formation of disulfide bonds in the Escherichia coli periplasm via coexpression of yeast protein disulfide isomerase.
Sacchromyces cerevisiae protein disulfide isomerase (yPDI) was expressed in the E. coli periplasm by using plasmids encoding the OmpA-yPDI-(His)(6) fusion gene under the control of the araBAD, trc, or T7 promoter. The expression levels of yeast PDI under these promoters were compared. Our results showed that yeast PDI expressed into the periplasm could catalyze the formation of disulfide bonds in alkaline phosphatase, restoring the phoA(+) phenotype in dsbA(-) mutants. The yeast PDI was purified from the Escherichia coli periplasm and shown to exhibit catalytic properties comparable to those of the rat enzyme with reduced RNase as substrate. In vivo, coexpression of the yeast PDI increased the yield of bovine pancreatic trypsin inhibitor (BPTI) in E. coli by 2-fold, similar to the effect seen previously with the coexpression of the rat enzyme. However yeast PDI was more effective than rat PDI in facilitating the expression of active tissue plasminogen activator (tPA). These results point to differences in the substrate specificity of various PDI enzymes, at least in the context of the E. coli periplasm.
Animals↗
Percutaneous optical imaging system to track reporter gene expression from vasculatures in vivo.
This study develops a percutaneous optical imaging system for tracking fluorescent reporter gene expression in vasculatures. We build a percutaneous optical imaging system that primarily comprised a 1.5-mm, semi-rigid, two-port optical probe. The performance of the optical probe is first tested in vitro with cell phantoms, and then the feasibility of the percutaneous optical imaging system is validated in vivo in eight femoral artery segments of two pigs. The green fluorescent protein (GFP) gene is locally delivered into four arterial segments, while saline is delivered to the four contralateral arterial segments as controls. The targeted arteries are localized using color Doppler, and thereafter the optical probe is positioned to the target arterial segments under ultrasound guidance. Optical imaging captures are obtained using different exposure times from 10 to 60 s. Subsequently, the GFP- and saline-targeted arteries are harvested for fluorescent microscopy confirmation. The percutaneous optical probe is successfully positioned at a distance approximately 2 mm from the targets in all eight arteries. The in-vivo imaging shows higher average signal intensity in GFP-treated arteries than in saline-treated arteries. This study demonstrates the potential using the percutaneous optical imaging system to monitor, in vivo, reporter gene expression from vasculatures.
Animals↗