Contrast-Enhanced X-Ray Micro-Computed Tomography as a Versatile Method for Anatomical Studies of Adult Zebrafish.

One attractive quality of zebrafish as a model organism for biological research is that transparency at early developmental stages allows the optical imaging of cellular and molecular events. However, this advantage cannot be applied to adult zebrafish. In this study, we explored the use of contrast-enhanced X-ray micro-computed tomography (microCT) on adult zebrafish in which the organism was stained with iodine, a simple and economical contrasting agent, after fixation. Tomographic reconstruction of the microCT data allowed the three-dimensional (3D) volumetric analyses of individual organs in adult zebrafish. Adipose tissues showed a higher affinity to iodine and were more strongly contrasted in microCT. As traditional histological techniques often involve dehydration steps that remove tissue lipids, iodine-contrasted microCT offers a convenient method for visualizing fat deposition in fish. Utilizing this advantage, we discovered a transient accumulation of lipids around the heart after ventricular amputation, suggesting a correlation between lipid distribution and heart regeneration. Taken together, microCT is a versatile technique that enables the 3D visualization of zebrafish organs, as well as other fish models, in their anatomical context. This simple method is a valuable new addition to the arsenal of techniques available to this model organism.

Characterization of clopidogrel hypersensitivity reactions and management with oral steroids without clopidogrel discontinuation.

OBJECTIVES: The purpose of this study was to characterize clopidogrel hypersensitivity and describe its successful management with oral steroids without clopidogrel discontinuation. BACKGROUND: Hypersensitivity reactions to clopidogrel are poorly understood and present difficulty in management. METHODS: Patients diagnosed with clopidogrel hypersensitivity after percutaneous coronary intervention underwent evaluation and received oral prednisone without clopidogrel discontinuation. Cutaneous testing was performed after completion of clopidogrel therapy for diagnosis and assessment of cross-reactivity. RESULTS: Sixty-two patients representing 1.6% of the percutaneous coronary intervention population developed clopidogrel hypersensitivity during the study period. The mean age was 62 ± 11 years, 71% of patients were male, and 35% reported prior adverse drug reaction. Clopidogrel hypersensitivity manifested as generalized exanthema in 79%, localized skin reaction in 16%, and angioedema or urticaria in 5% of patients. Biopsy of affected areas demonstrated a lymphocyte-mediated delayed hypersensitivity reaction. Complete resolution of hypersensitivity reaction was observed in 61 patients (98%) with a short course of oral prednisone. Cutaneous testing confirmed delayed hypersensitivity reaction to clopidogrel in 34 (81%) and immediate hypersensitivity in 3 of 42 patients (7%) tested. Allergenic cross-reactivity was observed for ticlopidine in 10 (24%), prasugrel in 7 (17%), and both ticlopidine and prasugrel in 3 patients (7%). Histological examination showed lymphocyte-mediated hypersensitivity in abnormal patch test areas. CONCLUSIONS: Clopidogrel hypersensitivity is manifested as generalized exanthema and is caused by a lymphocyte-mediated delayed hypersensitivity in most patients. This can be managed with oral steroids without clopidogrel discontinuation. Allergenic cross-reactivity with ticlopidine, prasugrel, or both is present in a significant number of patients with clopidogrel hypersensitivity.

Characterization of operator learning curve for transradial coronary interventions.

BACKGROUND: Transradial percutaneous coronary intervention (TR-PCI) improves clinical outcomes compared to the transfemoral (TF) approach. However, inadequate training and experience has limited widespread adoption by interventional cardiologists. METHODS AND RESULTS: Clinical and procedural characteristics for TR-PCI were prospectively collected from 1999 to 2008. To identify minimum case volume for optimum clinical benefit, single-vessel TR-PCI cases were chronologically ranked and stratified into 1 to 50, 51 to 100, 101 to 150 and 151 to 300 case volume groups for operators starting the TR approach at the study institution. Cases by operators with a >300 TR-PCI case volume comprised the control group. TR-PCI failure rates, contrast use, guide usage, and fluoroscopy time were compared among groups. A total of 1672 patients underwent TR-PCI by 28 operators. TR-PCI failure occurred in 4% and was higher in the 1 to 50 case volume group compared to the 51 to 100 (P=0.007) and control (P=0.01) groups. Contrast use was greater in the 1 to 50 group (180±79 mL) compared to the 151 to 300 (157±75 mL, P=0.02) and control (168±79 mL, P=0.05) groups. Fluoroscopy time was higher in the 1 to 50 group (15±10 minutes) compared to the 101 to 150 (13±10 minutes, P=0.04) and control (12±9 minutes, P=0.02) groups. Reasons for TR-PCI failure included spasm (38%), subclavian tortuousity (16%), poor guide support (16%), failed access (10%), and radial loop (7%). Case volume was significantly correlated with TR-PCI failure (ß=-0.0076, P=0.0028), and odds of failure was reduced by 32% for each 50 increments in case volume. CONCLUSIONS: TR-PCI success depends on operator experience, and a case volume of ≥50 cases is required to achieve outcomes comparable to experienced operators. These findings have implications both for PCI operators looking to expand their skills and for defining standards for training.

Efficacy and long-term safety of StarClose™ for hemostasis of arterial puncture sites distal to common femoral artery bifurcation after percutaneous coronary interventions.

BACKGROUND: Currently approved vascular closure devices (VCDs) are not recommended for use in arterial puncture sites distal to the common femoral artery (CFA) bifurcation. The StarClose™ vascular system (SC) is a unique VCD that does not contain intravascular components, a feature that may allow safe use in smaller vessels. OBJECTIVE: We sought to determine the efficacy and long-term safety of the SC for hemostasis of arterial punctures distal to the CFA bifurcation. METHODS: Consecutive patients with arterial puncture sites located distal to the CFA bifurcation received SC after percutaneous coronary intervention (PCI). Patients were ambulated 4-6 hours later, and the presence of vascular complications was determined clinically before hospital discharge. Clinical and Doppler ultrasound examinations were performed at 8-9 months to assess long-term safety. RESULTS: A total of 106 patients undergoing PCI were included in the study. Mean age was 66 ± 12 years and 63% were male. The arterial puncture site was located in the superficial femoral artery (SFA) in 76 (72%), the profunda femoris artery (PFA) in 22 (21%) and undetermined in 8 (7%) patients. The mean diameter of the CFA was significantly greater than the SFA or the PFA branch with the SC (6.2 ± 1.5 vs. 4.5 ± 1.0 mm for the CFA and branch with SC, respectively; p < 0.0001). Device success was achieved in 102 (96%) patients. At 24 hours, a hematoma ≥ 5 cm was reported in 13 (12%) patients. No other vascular complications occurred. At a mean follow up of 9 ± 2.5 months, there was no clinical or Doppler evidence of arterial insufficiency or vascular complications. CONCLUSION: The SC can be used for hemostasis after PCI in select cases where the arterial puncture site is located distal to the CFA bifurcation without adverse clinical outcomes.

Comparison of abciximab and eptifibatide on angiographic and clinical outcomes in rescue percutaneous coronary intervention for failed fibrinolytic therapy.

BACKGROUND: Adjunctive administration of the glycoprotein IIb/IIIa platelet receptor antagonist (GPA), abciximab, improves outcomes in patients undergoing rescue percutaneous coronary intervention (PCI). However, it is unknown if other GPAs provide a similar benefit in this setting. OBJECTIVE: We sought to compare angiographic and clinical outcomes of patients receiving abciximab or eptifibatide as an adjunct to rescue PCI. METHODS: In this prospective, nonrandomized study, consecutive patients who underwent rescue PCI and received adjunctive preprocedural GPA comprised the study population. Thrombolysis in myocardial infarction (TIMI) flow, corrected TIMI frame count (CTFC) and myocardial blush grade (MBG) were determined before and immediately after rescue PCI. Residual ST-segment elevation at 90-120 minutes and peak creatine kinase (CK) values for 48 hours after PCI were recorded. Major adverse cardiac events (MACE) including death, reinfarction and target vessel revascularization (TVR) were determined at discharge, 1 and 6 months. RESULTS: A total of 241 patients were included in the study. 162 patients received abciximab and 79 received eptifibatide. There were no differences in baseline clinical and angiographic characteristics between groups. Post-PCI TIMI flow was similar but post-PCI CTFC was significantly lower (17 +/- 10 vs. 22 +/- 18; p = 0.01) and post-PCI MBG significantly higher (2.8 +/- 0.5 vs. 2.6 +/- 0.6; p = 0.01) in the abciximab group. Patients in the abciximab group had less ST-segment elevation (1.0 +/- 0.9 vs. 1.5 +/- 1.0 mm; p = 0.003) and lower peak CK (2,484 +/- 2,176 vs. 2,650 +/- 2,798 U/L; p = 0.001) after PCI. On multivariate analyses, abciximab administration (OR = 0.50, CI = 0.26, 0.96; p = 0.03), pre-PCI TIMI 3 flow (OR = 0.22, CI = 0.05, 0.99; p = 0.04) and female gender (OR = 0.24, CI = 0.08, 0.66; p = 0.006) were positive and cardiogenic shock (OR = 2.76, CI = 1.16, 6.58; p = 0.02) was a negative predictor of normal epicardial perfusion post PCI. Abciximab administration (OR = 0.46, CI = 0.24, 0.87; p = 0.02) and pre-PCI CTFC < 25 (OR = 0.09, CI = 0.02, 0.31, 0.0001) were positive predictors and cardiogenic shock (OR = 3.96, CI = 1.55, 10.12; p = 0.004) was a negative predictor of normal myocardial perfusion post-PCI as determined by CTFC. Abciximab administration (OR = 0.31, CI = 0.15, 0.63; p = 0.001) and pre-PCI MBG 3 (OR = 0.07, CI = 0.02, 0.23; p < 0.0001) were positive predictors of normal myocardial perfusion post-PCI as determined by MBG. In-hospital, 1- and 6-month clinical events and MACE rates did not differ between groups. CONCLUSIONS: In the setting of rescue PCI, adjunctive administration of abciximab resulted in greater improvement in angiographic and electrical estimates of myocardial perfusion and smaller infarct size compared to eptifibatide. These findings suggest that all GPA may not provide equal benefit in rescue PCI.

Mechanism and predictors of failed transradial approach for percutaneous coronary interventions.

OBJECTIVES: The study aimed to determine the mechanism and predictors of procedural failure in patients undergoing percutaneous coronary intervention (PCI) from the transradial approach (TR). BACKGROUND: Transradial approach PCI reduces vascular complications compared with a transfemoral approach (TF). However, the mechanism and predictors of TR-PCI failure have not been well-characterized. METHODS: The study population consisted of patients undergoing TR-PCI by low-to-intermediate volume operators with traditional TF guide catheters. Baseline characteristics, procedure details, and clinical outcomes were prospectively collected. Univariate and multivariate analyses were performed to determine independent predictors of TR-PCI failure. RESULTS: A total of 2,100 patients underwent TR-PCI and represented 38% of PCI volume. Mean age was 64 +/- 12 years, and 17% were female. Vascular complications occurred in 22 (1%), and TR-PCI failure was observed in 98 (4.7%) patients. The mechanism of TR-PCI failure included inability to advance guide catheter to ascending aorta in 50 (51%), inadequate guide catheter support in 35 (36%), and unsuccessful radial artery puncture in 13 (13%) patients. The PCI was successful in 94 (96%) patients with TR-PCI failure by switching to TF. On multivariate analysis, age >75 years (odds ratio [OR]: 3.86; 95% confidence interval [CI]: 2.33 to 6.40, p = 0.0006), prior coronary artery bypass graft surgery (OR: 7.47; 95% CI: 3.45 to 16.19, p = 0.0002), and height (OR: 0.97; 95% CI: 0.95 to 0.99, p = 0.02) were independent predictors of TR-PCI failure. CONCLUSIONS: Transradial approach PCI can be performed by low-to-intermediate volume operators with standard equipment with a low failure rate. Age >75 years, prior coronary artery bypass graft surgery, and short stature are independent predictors of TR-PCI failure. Appropriate patient selection and careful risk assessment are needed to maximize benefits offered by TR-PCI.

Viral clearance using disposable systems in monoclonal antibody commercial downstream processing.

Once highly selective protein A affinity is chosen for robust mAb downstream processing, the major role of polishing steps is to remove product related impurities, trace amounts of host cell proteins, DNA/RNA, and potential viral contaminants. Disposable systems can act as powerful options either to replace or in addition to polishing column chromatography to ensure product purity and excellent viral clearance power for patients' safety. In this presentation, the implementation of three disposable systems such as depth filtration, membrane chromatography, and nanometer filtration technology in a commercial process are introduced. The data set of viral clearance with these systems is presented. Application advantages and disadvantages including cost analysis are further discussed.

Intraluminal filling defects on coronary angiography: more than meets the eye.

Intraluminal filling defects are occasionally encountered on coronary angiography and often related with coronary thrombi. However, other conditions affecting the coronary arteries may present with similar angiographic findings causing diagnostic uncertainty. Accurate characterization of the angiographic filling defect is critical, particularly in patients planned for a percutaneous coronary intervention (PCI), as diagnosis of a coronary thrombus not only increases the risk of post procedural adverse events but also requires a specific therapeutic approach. In this paper, we report three patients in whom coronary angiography revealed intraluminal filling defects mimicking coronary thrombi. When further investigated with intravascular ultrasound (IVUS) as a part of the planned PCI, the thrombus was excluded and alternate etiology of the filling defect was confirmed in all patients. The angiographic "pseudothrombi" were produced by coronary dissection in one and by heavy calcification within the atherosclerotic plaque in two patients. The use of IVUS allowed accurate characterization of the angiographic filling defect and provided important information to guide management and optimize therapeutic approach.

Buddy wire technique for stent placement at non-aorto ostial coronary lesions.

Percutaneous coronary intervention (PCI) of coronary non-aorto ostial lesions offers technical challenges not encountered with other lesion sub types. Stenting of these lesions improves acute angiographic result and lowers the rate of restenosis. However, precise stent placement at non-aorto ostial lesions is technically difficult with risk of incomplete lesion coverage or jailing of the main branch. In this report, we describe a buddy wire technique to facilitate precise stent placement at non-aorto ostial lesions.

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.

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.

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.

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.