Acoustic Activation Imaging With Intravenous Perfluoropropane Nanodroplets Results in Selective Bioactivation of the Risk Area.

Background: Acoustically activatable perfluoropropane droplets (PD) can be formulated from commercially available microbubble preparations. Diagnostic transthoracic ultrasound frequencies have resulted in acoustic activation (AA) predominately within myocardial infarct zones (IZ).

Objective: We hypothesized that the AA area following acute coronary ischemia/reperfusion (I/R) would selectively enhance the developing scar zone, and target bioeffects specifically to this region.

Acoustic Detection of Retained Perfluoropropane Droplets Within the Developing Myocardial Infarct Zone.

Perfluoropropane droplets (PDs) cross endothelial barriers and can be acoustically activated for selective myocardial extravascular enhancement following intravenous injection (IVI). Our objective was to determine how to optimally activate extravascular PDs for transthoracic ultrasound-enhanced delineation of a developing scar zone (DSZ). Ultrafast-frame-rate microscopy was conducted to determine the effect of pulse sequence on the threshold of bubble formation from PDs.

Efficacy of Sonothrombolysis Using Acoustically Activated Perflutren Nanodroplets versus Perflutren Microbubbles.

Nanoscale-diameter liquid droplets from commercially available microbubbles may optimize thrombus permeation and subsequent thrombus dissolution (TD). Thrombi were made using fresh porcine arterial whole blood and placed in an in vitro vascular simulation. A diagnostic ultrasound probe in contact with a tissue-mimicking phantom tested intermittent high-mechanical-index (HMI) fundamental multipulse (focused ultrasound [FUS], 1.

Delayed Echo Enhancement Imaging to Quantify Myocardial Infarct Size.

Background: Perfluoropropane droplets formulated from commercial microbubbles exhibit different acoustic characteristics than their parent microbubbles, most likely from enhanced endothelial permeability. This enhanced permeability may permit delayed echo-enhancement imaging (DEEI) similar to delayed enhancement magnetic resonance imaging (DE-MRI). We hypothesized this would allow detection and quantification of myocardial scar.

Selective infarct zone imaging with intravenous acoustically activated droplets.

Background: Microbubbles (MB) can be compressed to nanometer-sized droplets and reactivated with diagnostic ultrasound; these reactivated MB possess unique imaging characteristics.

Objective: We hypothesized that droplets formed from compressing Definity MB may be used for infarct-enhancement imaging.

Methods: Fourteen rats underwent ligation of their left anterior descending (LAD) artery, and five pigs underwent 90 minute balloon occlusions of their mid LAD.

Location and structure of fibrous sheath formed after placing a tunneled hemodialysis catheter in a large pig model.

Background And Objectives: We evaluated the location and structure of the fibrous sheath formed after the placement of tunneled, cuffed hemodialysis catheters in large animals, 70 kg pigs. We focused on describing the location of the fibrous sheath in relation to the catheter. Its location explains the fibrous sheath's ability to cause catheter dysfunction by covering the catheter exit ports located at the catheter's tip.

Surgical technique of placement of an external jugular tunneled hemodialysis catheter in a large pig model.

Background: Currently, there is insufficient knowledge about the surgical anatomy and surgical techniques in large animals that can be used to test medical devices designed for human use. We encountered this problem in our study requiring the placement of jugular vein, tunneled, cuffed hemodialysis catheter in 70 kg pigs. Despite the operator's extensive expertise in placing tunneled hemodialysis catheters in humans, the important differences in anatomy made the procedure and choosing the appropriate catheter length challenging.

Sheep Model of Hemodialysis Arteriovenous Fistula Using Superficial Veins.

Current models of animal arteriovenous fistula (AVF) are swine models of femoral vein terminolaterally anastomosed to femoral artery, creating a deep AVF. This feature sets it aside from human AVFs using superficial veins. Our AVF model uses sheep superficial veins to create an AVF almost identical to human model.

Modification of the genetic program of human alveolar macrophages by adenovirus vectors in vitro is feasible but inefficient, limited in part by the low level of expression of the coxsackie/adenovirus receptor.

Robust expression of genes transferred by adenovirus (Ad) vectors depends upon efficient entry of vectors into target cells. Cells deficient in the coxsackie/adenovirus receptor (CAR) are difficult targets for Ad-mediated gene transfer. We hypothesized that low levels of CAR expression may be responsible, in part, for the relative inefficiency of Ad-mediated gene transfer to human alveolar macrophages (AMs).

Penicillinase-producing strains of Neisseria gonorrhoeae isolated in Rotterdam.

This appears to be the first report of the isolation of a penicillinase-producing strain of Neisseria gonorrhoeae in the Netherlands. The presence of a penicillinase-producing gonococcal strain (PPGS) was demonstrated in two of a group of three patients with gonorrhoea. In addition, a penicillin- and ampicillin-sensitive gonococcus strain was isolated from all three patients.