Impact of ischemia-reperfusion on extracellular matrix processing and structure of the basement membrane of the heart.

Purpose: Acute ischemic injury is a strong inductor of cardiac remodelling, resulting in structural changes of the extracellular matrix (ECM) and basement membrane (BM). In a large animal model of ischemia-reperfusion (I/R) we investigated the post-ischemic liberation of the collagen-IV-fragments Tumstatin (TUM; 28 kDa-fragment of collagen-IV-alpha-3), Arresten (ARR; 26 kDa-fragment of collagen-IV-alpha-1) and Endorepellin (LG3, 85 kDa-fragment of perlecan) which are biologically active in angiogenesis and vascularization in the post-ischemic myocardium.

Methods And Results: In this blinded study, 30 pigs were randomized to 60 min of global I/R at either 4°C or 32°C or served as control.

Experimental immediate loading of dental implants in conjunction with grafting procedures.

The aim of this study was to evaluate immediate loading (IL) of dental implants in conjunction with grafting procedures. A total of 107 IL implants were inserted in six mini pigs. Before implant placement, crestal or apical defects were created, which were treated with bone chips, phycogene hydroxyapatite (HA), bovine HA, or bovine HA enhanced with a synthetic peptide.

Influence of host periosteum and recipient bed perforation on the healing of onlay mandibular bone graft: an experimental pilot study in the sheep.

Purpose: The aim of this study was to evaluate the role of host periosteum and recipient bed perforation on the healing of an onlay graft to the mandible based on histologic and immunohistochemical analysis.

Materials And Methods: Each of the 12 adult sheep used in the study received four iliac corticocancellous onlay bone grafts on the lateral surface of the mandible. In experiment 1, the block graft was placed in direct contact with the recipient bed and fixed with micro-screws, and in experiment 2, the recipient cortical bed was perforated before graft placement.

Pneumocyte apoptosis induction during cardiopulmonary bypass: effective prevention by radical scavenging using N-acetylcysteine.

Cardiopulmonary bypass (CPB) and cardioplegic arrest are associated with pulmonary dysfunction. We sought to investigate whether pulmonary ischemia/reperfusion during standard CPB and cardioplegic arrest is associated with reactive oxygen species (ROS)-mediated pulmonary tissue injury and pneumocyte apoptosis induction, and whether ROS scavenging using N-acetylcysteine (NAC) attenuates these alterations. Twelve pigs (41 +/- 8 kg) were randomized to receive either NAC (100 mg/kg prior to CPB; n = 7) or placebo (n = 5) and subjected to CPB and 60 min of cold (4 degrees C) crystalloid cardioplegic arrest.

LIFEBRIDGE: a portable, modular, rapidly available "plug-and-play" mechanical circulatory support system.

Purpose: We describe the LIFEBRIDGE, a portable, modular, rapidly available "plug-and-play" mechanical circulatory support system, and report its experimental safety evaluation.

Description: The modular construction consists of a disposable patient module with cardiopulmonary bypass circuit, control module, and base module with power supply, embedded PC, and user interface. The system weighs about 20 kg, has a modular design, and has semi-automatic priming that allows action within 5 minutes, and a 7-step air elimination program that prevents air embolization.

Pharmacologic cerebral capillary blood flow improvement after deep hypothermic circulatory arrest: an intravital fluorescence microscopy study in pigs.

Background: Despite meticulous investigation of bypass techniques for deep hypothermic circulatory arrest, unfavorable long-term neurologic deficits have been well documented. Our aim was to improve brain perfusion by reducing platelet plugging with a glycoprotein IIb/IIIa inhibitor (eptifibatide) in an experimental model of deep hypothermic circulatory arrest-reperfusion in pigs.

Methods: Two groups of 12 piglets each (eptifibatide group [eptifibatide + unfractionated heparin] vs UFH group [only unfractionated heparin]) underwent 10 minutes of normothermic bypass, 40 minutes of cooling during cardiopulmonary bypass (hematocrit, 30%; cardiopulmonary bypass flow, 100 mL x kg(-1) x min(-1)), 60 minutes of circulatory arrest at 15 degrees C, and a 40-minute rewarming period.

Effect of the Na+/H+ exchange inhibitor eniporide on cardiac performance and myocardial high energy phosphates in pigs subjected to cardioplegic arrest.

Background: Pharmacologic Na(+)/H(+) exchange inhibition has been suggested to ameliorate cardiac performance depression associated with myocardial ischemia/reperfusion. The purpose of our experimental study was to investigate the impact of the novel Na(+)/H(+) exchange inhibitor Eniporide (EMD 96785) on cardiac performance and high energy phosphate content in a clinically relevant pig model of cardioplegic arrest.

Methods: We subjected 21 pigs (47 +/- 12 [SD] kg) to cardiopulmonary bypass (CPB) and 60 minutes cold (4 degrees C) crystalloid cardioplegic arrest (Bretschneider).

Cardioplegic arrest induces apoptosis signal-pathway in myocardial endothelial cells and cardiac myocytes.

Objective: Myocardial ischemia-reperfusion is associated with free radical-mediated injury and may be involved in cardiac apoptosis. The purpose of our study was to investigate (1) if cardioplegia-induced ischemia-reperfusion initiates cardiac apoptosis signal pathway, and (2) if this is mediated by free radicals.

Methods: We subjected 13 pigs (56+/-10 kg) to 1 h of cold crystalloid cardioplegic arrest (CA) on cardiopulmonary bypass (CPB), and collected five transmural LV biopsies: prior to CPB (baseline), at 60 min CA, at 15 and 30 min reperfusion on CPB, and at 120 min post CPB.