True Effects or Bias? MMP-2 and MMP-9 Serum Concentrations after Acute Stroke.

Background: Average serum matrix metalloproteinase (MMP) concentrations in patients with acute stroke have shown to be varying across studies. Possibly, next to true effects, other factors may influence MMP levels. The aim of this study was to investigate the dynamics of these enzymes in repeated measurements in the acute post-stroke period, in respect to different stroke etiologies, and highlight potential sources for variability.

MMP-2 concentrations in stroke according to etiology: adjusting for enzyme degradation in stored deep-frozen serum and other methodological pitfalls.

Matrix metalloproteinases (MMP) have a prominent role in the pathophysiology of stroke. We investigated potential differences in MMP-2 concentrations with respect to acute stroke etiology. For another MMP family member, MMP-9, significant degradation over time has been found even when stored at -80 °C, so we measured temporal degradation of MMP-2 and adjusted for this and other factors potentially affecting our results.

TIMP-2 gene polymorphism is associated with intracerebral hemorrhage.

Background: Both ischemic stroke and intracerebral hemorrhage are associated with altered expression and activation of matrix metalloproteinases (MMPs). Particularly relevant are MMP-2 and MMP-9. This proteolytic effect is dampened by tissue inhibitors of metalloproteinases (TIMPs).

In vivo clot lysis of human thrombus with intravenous abciximab immunobubbles and ultrasound.

Abciximab immunobubbles have been introduced recently for ultrasonographic molecular imaging of human thrombus. This study investigates the potential of using these novel bubbles for enhancing sonothrombolysis. In particular, it addresses the question of whether ligand targeting of bubbles with abciximab improves the effectiveness of lysis with ultrasound.

Lipoaspirate-derived adult mesenchymal stem cells improve functional outcome during intracerebral hemorrhage by proliferation of endogenous progenitor cells stem cells in intracerebral hemorrhages.

Stem cell therapy seems promising in reducing deficits after focal cerebral ischemia. As stroke may result from intracerebral hemorrhage (ICH) in up to 20% we investigated whether human processed lipoaspirate mesenchymal stem cells (PLA-MSC) influence the functional outcome, migration behavior and the activation of endogenous progenitor cells. Experimental ICH was induced by stereotactic administration of collagenase in rats randomly assigned to the control or treatment group.

Improved detection of intracerebral hemorrhage with transcranial ultrasound perfusion imaging.

Background: Ultrasound perfusion imaging (UPI) is a new approach for the assessment of brain perfusion. In contrast to the increasing experience with this method in patients with ischemic stroke, data on the value of UPI for the diagnosis of intracerebral hemorrhage (ICH) are lacking.

Methods: We investigated 12 consecutive patients with sufficient temporal bone windows and a CT diagnosis of acute supratentorial ICH (basal ganglia n = 9 and lobar n = 3).

Single-nucleotide polymorphisms of MMP-2 gene in stroke subtypes.

Background: Matrix metalloproteinases (MMP) are expressed after ischemic stroke. These proteases are responsible for a higher incidence of hemorrhages, are correlated to size of infarction and influence the effects of recombinant tissue plasminogen activator treatment. We therefore evaluated single nucleotide polymorphisms (SNP) of MMP-2 in different subtypes of stroke patients in an association study using a case-control design.

Infrared spectroscopy: a new diagnostic tool in Alzheimer disease.

Biological markers play an evolving role in the diagnosis of Alzheimer disease (AD). We compare conventional measurements of cerebrospinal fluid (CSF) tau and beta-amyloid(1-42) proteins to a novel approach - Fourier transformed infrared (FT-IR) spectroscopy - a simple technique derived from chemical and physical sciences that characterizes intramolecular bonds. For automatic diagnostic analysis, we developed an artificial neural network (ANN).

Molecular imaging of human thrombus with novel abciximab immunobubbles and ultrasound.

Background And Purpose: Molecular imaging of therapeutic interventions with targeted agents that simultaneously carry drugs or genes for local delivery is appealing. We investigated the ability of a novel microbubble carrier (immunobubble) for abciximab, a glycoprotein IIb/IIIa receptor inhibitor, for ultrasonographic molecular imaging of human clots.

Methods: Human thrombi were incubated with immunobubbles conjugated with abciximab.

Gadofluorine m uptake in stem cells as a new magnetic resonance imaging tracking method: an in vitro and in vivo study.

Objectives: Cell tracking using ultrasmall iron particles is well established in magnetic resonance imaging (MRI). However, in experimental models, intrinsic iron signals derived from erythrocytes mask the labeled cells. Therefore, we evaluated Gadofluorine M with other gadolinium chelates for a T1-weighted positive enhancement for cell tracking in vitro.

Protein S-100B--a prognostic marker for cerebral damage.

The assessment of S-100B in acute neurological disorders such as global hypoxia, ischaemic or haemorrhagic stroke and traumatic brain injury reflects severity of symptoms and outcome. However, the temporal profile of S-100B release depends on topography, intensity and pathophysiology of the damage e.g.

Effects of simultaneous application of ultrasound and microbubbles on intracerebral hemorrhage in an animal model.

Microbubble-enhanced sonothrombolysis (MEST) may be an alternative therapeutic option in ischemic stroke. Clinical study of the efficacy of MEST as an adjunct stroke therapy, before imaging with CT or MRI, requires experimental data on the safety of this approach in the presence of hemorrhagic stroke. We, therefore, investigated the effect of diagnostic transcranial ultrasound combined with microbubbles (US + MB) in an experimental animal model of intracerebral hemorrhage (ICH).

Brain temperature during 340-kHz pulsed ultrasound insonation: a safety study for sonothrombolysis.

Background And Purpose: Because ultrasound is used for improving thrombolysis of cerebral infarction but continuous ultrasound insonation also has significant thermal effects, we evaluated brain temperature increase and tissue destruction during pulsed ultrasound emission.

Methods: We examined 340-kHz pulsed ultrasound effects in male Wistar rats. Ultrasound was applied transcranially for 30 minutes on different power levels (1 to 7 W/cm2).

Matrix metalloproteinases in cerebrovascular diseases.

Matrix metalloproteinases are important factors for tissue remodelling and are activated during several physiological and pathological conditions, including cerebrovascular diseases. We give an overview of the structure, production and physiological effects of these widely distributed proteases and describe the genetic background and regulation pathways. In particular, we discuss the role of matrix metalloproteinases in vascular remodelling concerning ischaemic stroke, brain haemorrhage, vascular dementia, carotid artery plaques and cerebral aneurysms.

High doses of simvastatin, pravastatin, and cholesterol reduce brain cholesterol synthesis in guinea pigs.

Recent epidemiological studies suggest that inhibitors of 3-hydroxy-3-methyl-glutaryl CoA reductase, so-called statins, are effective in lowering the prevalence of Alzheimer's disease. Whether the effect of statins is due to a local inhibition of cholesterol synthesis in the brain or whether it is mediated by the reduced levels of cholesterol in the circulation is not known. In the present work, we tested the possibility that high doses of lipophilic and hydrophilic statins, simvastatin and pravastatin, respectively, or a diet high in cholesterol could affect cholesterol homeostasis in the brain of guinea pigs.

Influence of simvastatin, pravastatin, and BM 15.766 on neutral sterols in liver and testis of guinea pigs.

There is mounting evidence that specific sterol precursors of cholesterol are associated with reproductive functions. Testicular meiosis-activating sterol (T-MAS) and follicular fluid meiosis-activating-sterol (FF-MAS) are 2 cholesterol precursors found in reproductive organs of mammals, which are able to overcome meiotic arrest in vitro. This study investigates the influence of simvastatin and pravastatin, 2 inhibitors of 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase, and BM 15.