Gregor Freude

Universität Ulm, Ulm, Baden-Wuerttemberg, Germany

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Publications (3)8.71 Total impact

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    ABSTRACT: Locally applied hemostatic agents, mostly consisting of gelatinous granules with admixed human or bovine thrombin, are used in various surgical procedures. In our case, a 78-year-old woman underwent neurosurgical removal of an extraforaminal schwannoma of the L5 dorsal root ganglion. During the procedure, the hemostatic matrix consisting of a meshwork of bovine gelatinous granules admixed with human thrombin was locally applied to control diffuse paravertebral bleeding. Eight hours after surgery, the patient developed dyspnea with right heart failure and finally died. At autopsy, we found complete occlusion of the left pulmonary artery with a large thromboembolus. Histologically, that thromboembolus consisted of gelatinous granules with only a thin rim of surrounding, classic parietal thrombus. To our knowledge, this is the first description of fatal pulmonary embolization of a major lung artery with this material. The report depicts a possible life-threatening complication associated with the local application of hemostatic agents.
    Human pathology 11/2012; · 3.03 Impact Factor
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    ABSTRACT: There is an ongoing debate whether oximes can effectively counteract the effects of organophosphorus compounds (OP) on brain acetylcholinesterase (AChE) activity and whether there are differences in the kinetic properties of brain and erythrocyte AChE. In order to investigate the kinetics of AChE from different tissues and species the well established dynamically working in vitro model with real-time determination of membrane-bound AChE activity was adapted for use with brain AChE. The enzyme reactor, that was loaded with brain, erythrocyte or muscle AChE, was continuously perfused with substrate and chromogen while AChE activity was on-line analyzed in a flow-through detector. It was possible to determine the Michaelis-Menten constants of human erythrocyte, muscle and brain AChE which were almost identical. In addition, the inhibition kinetics of sarin and paraoxon as well as the reactivation kinetics of obidoxime and HI 6 were determined with human, swine and guinea pig brain and erythrocyte AChE. It was found that the inhibition and reactivation kinetics of brain and erythrocyte AChE were highly comparable in all tested species. These data support the view that AChE from different tissue has similar kinetic properties and that brain AChE is comparably susceptible toward reactivation by oximes.
    Toxicology Letters 03/2012; 209(2):173-8. · 3.15 Impact Factor
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    ABSTRACT: Syringomyelia without an obvious cause, such as a Chiari malformation, a tumor, or a spinal injury, is rare and may be associated with an arachnoid web or cyst. In the literature, conventional myelography is the diagnostic method of choice. In this retrospective study, we evaluated the diagnostic value of magnetic resonance imaging (MRI) cerebrospinal fluid (CSF) flow studies as compared with conventional myelography in patients with syringomyelia. From early 2003 to late 2006, 320 patients with syringomyelia underwent cardiac-gated phase-contrast MRI of CSF flow in the brain and spine. We assessed the presence of CSF flow blockage as well as syrinx site, shape, and size. Additional myelography was performed in 8 patients. CSF flow blockage and progressive neurological symptoms or progression of syringomyelia were indications for surgery. Syringomyelia without an obvious cause was found in 125 patients. CSF flow blockage was detected in 33 patients. Seven of these patients underwent cyst wall resection and decompression of the subarachnoid space via a unilateral approach without laminectomy. Myelography revealed CSF flow blockage in only 2 of 8 cases. In the other 6 patients, MRI detected a blockage and surgery revealed arachnoid cysts or webs. Postoperative CSF flow studies revealed free CSF flow in all 10 surgically treated patients. In 6 of these patients, syrinx size was reduced after surgery. Myelography should not be the method of choice for the diagnosis of idiopathic syringomyelia. MRI CSF flow studies were found to be more reliable.
    Neurosurgery 01/2009; 63(6):1139-44; discussion 1144. · 2.53 Impact Factor

Publication Stats

17 Citations
8.71 Total Impact Points

Institutions

  • 2012
    • Universität Ulm
      • Institute of Pathology
      Ulm, Baden-Wuerttemberg, Germany