Biomedical subjects

Tony Hong

Publications and source records attributed to Tony Hong.

4 recordsLinked to original sources

PubMed2007

Comparison of radial versus femoral approach for percutaneous coronary interventions in octogenarians.

BACKGROUND: The safety and efficacy of a radial approach for percutaneous coronary intervention (PCI) in octogenarians is not well established. METHODS: To evaluate the benefits of a radial approach for preventing vascular complications after PCI, clinical, procedural, and outcome data were prospectively collected and compared for 228 octogenarians undergoing elective PCI either through a radial or a femoral approach. RESULTS: Radial approach was associated with longer cannulation (3.1 +/- 2.9 vs. 2.0 +/- 2.0 min, P < 0.001) and fluoroscopy times (19.3 +/- 16.1 vs. 16.1 +/- 11.8 min, P = 0.04), greater utilization of contrast media (224 +/- 46 vs. 182 +/- 20 ml, P < 0.001) and higher crossover rate (11 vs 4%, P = 0.03) to alternate access site compared with the femoral approach. However, ambulation time (5.2 +/- 3.1 vs. 11.6 +/- 6.3 hr, P < 0.001), access site bleeding (4 vs. 14%, P = 0.007), hematoma (1 vs. 11%, P = 0.001) or any vascular complication (5 vs 26%, P = 0.001) were significantly reduced with a radial approach. Procedural success rates were equivalent with both approaches. Multivariate regression analysis identified radial approach (OR = 0.23; CI = 0.08, 0.65) as an independent negative predictor of postprocedural vascular complications. CONCLUSION: Radial approach for PCI in octogenarians is technically challenging for the operator and exposes patients to greater volume of nephrotoxic contrast media. However, it results in early ambulation and significantly reduces vascular complications in this high risk population. These findings support a strategy of preprocedural risk assessment and use of radial approach for PCI in a select group of octogenarians to maximize benefits offered by this technique.

Aged, 80 and over↗

PubMed2006

New Q membrane scale-down model for process-scale antibody purification.

Process-scale antibody production requires polishing steps with extremely high product throughput and robust operation. In this communication, the Sartobind Q membrane adsorber for process-scale antibody production is evaluated as an alternative to Q column chromatography. Although the capacity seen with large-scale membrane adsorbers is competitive with column chromatography, the same throughput is not achieved with the current scale-down models. The operational issues currently found in membrane scale-down models, including backpressure, which significantly compromises the membrane's capacity, were examined. A new scale-down model was designed to mimic the liquid flow path found in the large-scale capsule, and a new process capacity equivalent at both small and large scale was successfully achieved. Results of a 4-model virus study with a redesigned Sartobind Q absorber scale-down model at the new process capacity are presented.

Animals↗

PubMed2006

Adventitial microvessel formation after coronary stenting and the effects of SU11218, a tyrosine kinase inhibitor.

OBJECTIVES: The aim of this study was to delineate the temporal profile of adventitial microvessel (Ad-MV) formation after stenting, its relationship to arterial wall hypoxia, and the effects of a tyrosine kinase inhibitor (TKI), SU11218, on Ad-MV and in-stent intimal hyperplasia (IH). BACKGROUND: Adventitial microvessels have been reported after arterial injury; however, the underlying stimulus for this response and its relationship to IH is unknown. METHODS: Coronary stenting was performed in 40 pigs randomized to SU11218 (n = 20) or placebo (n = 20). Vessel wall hypoxia was assessed by pimonidazole adducts and hypoxia-inducible factor (HIF)-1 alpha expression. Adventitial microvessels were quantified by three-dimensional microscopic computed tomography (3D micro CT). Intimal hyperplasia was measured by intravascular ultrasound (IVUS), 3D micro CT, and morphometry. The effects of SU11218 were assessed in vitro on smooth muscle cell (SMC) and endothelial cell (EC) functions and in vivo on Ad-MV and IH. RESULTS: Hypoxia was evident in the vessel wall at 48 h and persisted for four weeks. Adventitial microvessels increased significantly at one week (24 +/- 7 microvessels/segment) and four weeks (23 +/- 7 microvessels/segment) compared with uninjured arteries (16 +/- 2 microvessels/segment; p < 0.001) and correlated with IH (r = 0.77, p < 0.001). The TKI SU11218 inhibited platelet-derived growth factor receptor-beta phosphorylation, EC and SMC DNA synthesis, and migration in a dose-dependent manner in vitro and significantly inhibited Ad-MV (16 +/- 5 vs. 23 +/- 7 microvessels/segment in placebo, p < 0.001) and produced approximately 80% reduction in IH (0.52 +/- 0.51 mm2 vs. 2.47 +/- 1.66 mm2 in placebo, p < 0.001) at four weeks in vivo. CONCLUSIONS: Arterial stenting causes arterial wall hypoxia followed by Ad-MV formation. The TKI SU11218 inhibits both Ad-MV formation and IH and represents a promising therapeutic agent to prevent in-stent restenosis.

Animals↗

PubMed2006

Side-strut stenting technique for the treatment of aorto-ostial in-stent restenosis and deformed stent struts.

Percutaneous coronary intervention for the treatment of aorto-ostial in-stent restenosis poses unique technical challenges not offered by other lesion subtypes. These difficulties are further enhanced when encountered with a case of deformed stent struts preventing coaxial guiding catheter engagement and introduction of guidewire through the true stent lumen. In this report, we describe a method of stenting through stent struts side-strut stenting for treating aorto-ostial in-stent restenosis associated with deformed stent struts resulting in good long-term outcome.

Acute Disease↗