The Potential Role of Neutrophil Gelatinase-Associated Lipocalin in the Development of Abdominal Aortic Aneurysms.

Background: In abdominal aortic aneurysm (AAA), pathophysiology deterioration of the medial aortic layer plays a critical role. Key players in vessel wall degeneration are reactive oxygen species (ROS), smooth muscle cell apoptosis, and extracellular matrix degeneration by matrix metalloproteinase-9 (MMP-9). Lipocalin-2, also neutrophil gelatinase-associated lipocalin (NGAL), is suggested to be involved in these degenerative processes in other cardiovascular diseases.

Systematic Review of Circulating, Biomechanical, and Genetic Markers for the Prediction of Abdominal Aortic Aneurysm Growth and Rupture.

Background: The natural course of abdominal aortic aneurysms (AAA) is growth and rupture if left untreated. Numerous markers have been investigated; however, none are broadly acknowledged. Our aim was to identify potential prognostic markers for AAA growth and rupture.

Betaglycan (TGFBR3) up-regulation correlates with increased TGF-β signaling in Marfan patient fibroblasts in vitro.

Background: Marfan syndrome (MFS), a congenital connective tissue disorder leading to aortic aneurysm development, is caused by fibrillin-1 (FBN1) gene mutations. Transforming growth factor beta (TGF-β) might play a role in the pathogenesis. It is still a matter of discussion if and how TGF-β up-regulates the intracellular downstream pathway, although TGF-β receptor 3 (TGFBR3 or Betaglycan) is thought to be involved.

Peroxynitrite Footprint in Circulating Neutrophils of Abdominal Aortic Aneurysm Patients is Lower in Statin than in Non-statin Users.

Objectives: Extensive reactive oxygen and nitrogen species (also reactive species) production is a mechanism involved in abdominal aortic aneurysm (AAA) development. White blood cells (WBCs) are a known source of reactive species. Their production may be decreased by statins, thereby reducing the AAA growth rate.

Intravenous Targeted Microbubbles Carrying Urokinase versus Urokinase Alone in Acute Peripheral Arterial Thrombosis in a Porcine Model.

Background: Standard therapy in acute peripheral arterial occlusion consists of intra-arterial catheter-guided thrombolysis. As microbubbles may be used as a carrier for fibrinolytic agents and targeted to adhere to the thrombus, we can theoretically deliver the thrombolytic medication locally following simple intravenous injection. In this intervention-controlled feasibility study, we compared intravenously administered targeted microbubbles incorporating urokinase and locally applied ultrasound, with intravenous urokinase and ultrasound alone.

Therapeutic application of contrast-enhanced ultrasound and low-dose urokinase for thrombolysis in a porcine model of acute peripheral arterial occlusion.

Background: The addition of local ultrasound (US) with a contrast agent to standard intra-arterial thrombolysis can accelerate the thrombolytic treatment of stroke and myocardial infarction. The contrast agent consists of microsized gas-filled bubbles that collapse when exposed to US, causing destabilization of the clot and making the clot surface more susceptible to fibrinolytics. In this study, we investigated the effect of additional US and microbubbles on standard low-dose intra-arterial thrombolysis in a porcine model of extensive peripheral arterial occlusion.

Robot-assisted ramicotomy: evaluation in a swine model.

Background: To evaluate the feasibility of robot-assisted thoracoscopic T2-T5 ramicotomy.

Methods: In 5 pigs, a robot-assisted thoracoscopic T2-T5 ramicotomy was performed, followed by T2-T5 sympathectomy 10 min later. Ramicotomy and sympathectomy times, and core (esophageal) and surface (left front foot) temperatures, were monitored and recorded.

Premature aging of the microcirculation in patients with advanced chronic kidney disease.

Background: Increasing age and advanced chronic kidney disease (CKD) are both associated with an attenuated vasodilator response of the skin microcirculation. In the present study, we investigated the effect of aging on microvascular reactivity in patients with advanced CKD.

Methods: Acetylcholine (ACh)-mediated endothelium-dependent vasodilation and sodium nitroprusside (SNP)-mediated endothelium-independent vasodilation were assessed by iontophoresis combined with laser Doppler flowmetry.

Migraine: possible role of shear-induced platelet aggregation with serotonin release.

Background: Migraine patients are at an increased risk for stroke, as well as other thromboembolic events. This warrants further study of the role of platelets in a proportion of migraine patients.

Objective: To extend the "platelet hypothesis" using literature data and observations made in a rat model of shear stress-induced platelet aggregation.

Hypothermic renal perfusion during aortic surgery reduces the presence of lipocalin-2 and preserves renal extraction of dimethylarginines in rats.

Cold perfusion through the renal arteries during renal ischemia has been suggested to diminish postoperative renal damage after juxtarenal aortic aneurysm repair. As the kidneys play a key role in dimethylarginine metabolism, which in turn is associated with renal hemodynamics, we hypothesized that the protective effect of cold perfusion is associated with a preserved renal extraction of dimethylarginines. Renal ischemia was induced in three groups of anesthetized Wistar rats (n = 7/group), which underwent suprarenal aortic clamping (45 min) with no perfusion (group 1), renal perfusion with 37°C saline (group 2), or renal perfusion with 4°C saline (group 3), respectively, followed by 90 min of renal reperfusion in all groups.

Capillary rarefaction in advanced chronic kidney disease is associated with high phosphorus and bicarbonate levels.

Background: In patients with chronic kidney disease (CKD), disorders of mineral metabolism are associated with vascular calcifications and mortality. Microvascular dysfunction, by affecting flow resistance and tissue perfusion, may explain the cardiovascular sequelae of CKD-associated disorders of mineral metabolism. We investigated whether advanced CKD is associated with a decrease in the functional and structural number of capillaries in skin and subsequently whether capillary rarefaction is related to mineral metabolism.

COX-2 Inhibition by Use of Rofecoxib or High Dose Aspirin Enhances ADP-Induced Platelet Aggregation in Fresh Blood.

Aim: Increased cardiovascular risk after use of selective or nonselective cyclooxygenase-2 (COX-2)-inhibitors might partly be caused by enhanced platelet aggregability. However, an effect of COX-2 inhibition on platelets has so far not been observed in humans.

Methods: We tested in healthy volunteers the effect of COX-2-inhibition nearly in-vivo, i.

ρ-Kinase inhibition reduces early microvascular leukocyte accumulation in the rat kidney following ischemia-reperfusion injury: roles of nitric oxide and blood flow.

Aim: To study whether microvascular leukocyte accumulation after rat renal ischemia and reperfusion (IR) is decreased by Rho kinase inhibition, independently of effects upon nitric oxide (NO) and renal blood flow.

Methods: Male Wistar rats were subjected to 60 min of ischemia by bilateral clamping and 60 min of reperfusion of the renal arteries, or a sham procedure. Haemodynamics were monitored and microsphere blood flow to the kidneys was measured.

Infrarenal aortic-clamping after renal ischaemia aggravates acute renal failure.

Background: Renal failure is a frequent complication of juxtarenal abdominal aortic aneurysm (JAA)-repair. During this operation, suprarenal aortic-clamping is followed by infrarenal aortic-clamping (below renal arteries) to restore renal flow, while performing the distal anastomosis. We hypothesized that infrarenal aortic-clamping, despite restoring renal perfusion provokes additional renal damage.

Peritoneal dialysis fluid bioincompatibility and new vessel formation promote leukocyte-endothelium interactions in a chronic rat model for peritoneal dialysis.

Peritoneal dialysis (PD)-induced peritonitis leads to dysfunction of the peritoneal membrane. During peritonitis, neutrophils are recruited to the inflammation site by rolling along the endothelium, adhesion, and transmigration through vessel walls. In a rat PD-model, long-term effects of PD-fluids (PDF) on leukocyte-endothelium interactions and neutrophil migration were studied under baseline and inflammatory conditions.

Juxtarenal aortic aneurysm repair.

Objectives: Juxtarenal aortic aneurysms (JAA) account for approximately 15% of abdominal aortic aneurysms. Despite advances in endovascular aneurysm repair, open repair requiring suprarenal aortic cross-clamping is still the treatment of choice for JAA. We performed a systematic review of the literature to determine perioperative mortality and postoperative renal dysfunction after open repair for non-ruptured JAA.

Open surgical repair of ruptured juxtarenal aortic aneurysms with and without renal cooling: observations regarding morbidity and mortality.

Objectives: Little is known about the outcome of ruptured juxtarenal aortic aneurysm (RJAA) repair. Surgical treatment of RJAAs requires suprarenal aortic cross-clamping, which causes additional renal ischemia-reperfusion injury on top of the pre-existing hypovolemic shock syndrome. As endovascular alternatives rarely exist in this situation, open repair continues to be the gold standard.

Magnetically navigated percutaneous coronary intervention in distal and/or complex lesions may improve procedural outcome and material consumption.

Aims: Comparison of magnetic guidewire navigation in percutaneous coronary intervention (magnetic PCI) across distal and/or complex lesions versus conventional navigation (conventional PCI).

Methods And Results: Forty-seven consecutive patients (age 61 +/- 10 yr) undergoing elective single vessel magnetic PCI for distal and/or complex lesions were matched by age and lesion location with 45 patients undergoing conventional PCI (age 63 +/- 10 yr). Technical success rate was defined as an intraluminal wire position distal to the stenosis.

Circulating white blood cells and platelets amplify oxidative stress in heart failure.

Background: Mitochondria of circulating white blood cells (WBC) and platelets sense oxidative stress during capillary passage and react by producing reactive oxygen species (ROS). Although evidence indicates that congestive heart failure (CHF) is associated with oxidative stress, the role of WBC and platelets as mediators in CHF has not been investigated.

Methods: Patients with CHF (n = 15) and healthy volunteers (n = 9) were enrolled between 2006 and 2007 into this observational study.

Leucocyte and platelet adhesion in different layers of the small bowel during experimental total warm ischaemia and reperfusion.

Background: Ischaemia and reperfusion (IR) of the small bowel is involved in many clinical conditions. A key component in IR-induced tissue damage is microvascular dysfunction. The aim was to investigate the role of leucocytes and platelets in capillary flow impediment and tissue damage.

Precision and reliability of retinal thickness measurements in foveal and extrafoveal areas of healthy and diabetic eyes.

Purpose: To determine the precision and reliability of retinal thickness measurements with an optical coherence tomograph (Stratus OCT 3; Carl Zeiss Meditec, Dublin, CA) and a retinal thickness analyzer (RTA; Talia Technology Ltd., Neve-Ilan, Israel) in foveal, parafoveal, and perifoveal areas.

Methods: Three measurements of all areas were performed within 1 hour on the same day with each instrument in the eyes of healthy volunteers and diabetic patients.

Platelet activation in clinical haemodialysis: LMWH as a major contributor to bio-incompatibility?

Background: The sum of undesirable side effects, occurring during haemodialysis (HD), is called bio-incompatibility. Concerning platelets, both an increase in the expression of the cell surface marker P-selectin (CD62p) and release of the intracellular granule product platelet factor 4 (PF4) have been described. However, as PF4 is also abundantly present on endothelium-bound proteoglycans, it is questionable whether the HD-induced increase is exclusively attributable to release from platelets.