Percutaneous injection of thrombin for the treatment of pseudoaneurysms: the German multicentre registry.

AIMS: False aneurysms can be treated surgically or by ultrasound guided manual compression. Another method is to inject thrombin into the aneurysm under ultrasound guidance. We evaluated safety and efficacy of this approach in a multicentre registry. METHODS AND RESULTS: In 595 consecutive patients a pseudoaneurysm (593 femoral arteries, 2 brachial arteries) was diagnosed 0 to 250 days (median 3 days) after a catheter procedure. The diameter of the aneurysm ranged from 0.5x0.5x0.5 (LxWxD) to 8x11x16 cm (median 2x2x1.6 cm). 20 U to 4000 U (median 400 U) of thrombin solution were injected into the aneurysm under ultrasound guidance.The procedure was technically successful in 587/595 (99%) patients.The aneurysms were thrombosed after the first injection in 531 (89%) patients. Thirty-eight (6%) patients needed a second injection and eight (1%) patients, a third injection because residual flow in the aneurysm was visible at follow-up. In four (0.7%) additional patients the thrombosis of the aneurysms was delayed and occurred only after 24 hours to seven days. Six (1%) patients surgery was performed after successful closure of the aneurysm to remove the resulting haematoma. The overall technical success rate was 99% and clinical success was achieved in 96%.Eight (1%) other patients underwent surgery due to thrombin injection failure.Complications occurred in nine patients (1,5%). Intravascular thrombus formation, deep venous thrombosis, pulmonary embolism due to deep venous thrombosis, transient paresthesia in the leg during injection. CONCLUSIONS: Ultrasound guided thrombin injection is a safe, effective and rapid treatment of false aneurysms. Complications and recurrent pseudoaneurysms are rare.

Validation of dual-chamber pacemaker diagnostic data using dual-channel stored electrograms.

BACKGROUND: Pacemaker diagnostic counters are used to guide device programming and patient management. However, these data are susceptible to inappropriate classification of events. The aim of this multicenter study was to evaluate pacemaker diagnostic data using stored intracardiac electrograms (EGMs). METHODS: The study included 351 patients (191 males, aged 71 +/- 10 years) with standard indications for dual-chamber pacemaker implantation. EGM triggers were atrial tachycardia (AT), ventricular tachycardia (VT), sudden bradycardia response (SBR), and pacemaker-mediated tachycardia (PMT). For this study, the devices could store up to 5 EGMs of 8s each (with marker annotation and onset recording). After 3 months, the EGMs were analyzed and classified as "confirmed" if the EGM validated the trigger and as "false positive" if the EGM showed an event different from the trigger. RESULTS: Of the 1,003 EGMs available, the triggers were AT in 640 EGMs, VT in 76, SBR in 105, and PMT in 178 EGMs. Four EGMs were triggered by magnet application. The trigger was confirmed in 614 EGMs (62%): 62% of AT episodes, 18% of VT episodes, 100% of SBR episodes, and 54% of PMT episodes. In 385 cases (45%), the EGMs revealed false-positive events due to far-field sensing (39%), noise and myopotential sensing (26%), sinus tachycardias (21%), double counting (9%), exit block (4%), and undersensing (1%). CONCLUSION: This large-scale study of stored EGMs revealed their value in validating diagnostic counter data. Therapeutic decisions should not be based on diagnostic counters alone; they should be validated by sophisticated tools like stored EGMs.

High-resolution crystal structures of Caldicellulosiruptor strain Rt8B.4 carbohydrate-binding module CBM27-1 and its complex with mannohexaose.

Carbohydrate-binding modules (CBMs) are the most common non-catalytic modules associated with enzymes active in plant cell-wall hydrolysis. Despite the large number of putative CBMs being identified by amino acid sequence alignments, only few representatives have been experimentally shown to have a carbohydrate-binding function. Caldicellulosiruptor strain Rt8B.4 Man26 is a thermostable modular glycoside hydrolase beta-mannanase which contains two non-catalytic modules in tandem at its N terminus. These modules were recently shown to function primarily as beta-mannan-binding modules and have accordingly been classified as members of a novel family of CBMs, family 27. The N-terminal CBM27 (CsCBM27-1) of Man26 from Caldicellulosiruptor Rt8B.4 displays high-binding affinity towards mannohexaose with a Ka of 1 x 10(7) M(-1). Accordingly, the high-resolution crystal structures of CsCBM27-1 native and its mannohexaose complex were solved at 1.55 angstroms and 1.06 angstoms resolution, respectively. In the crystal, CsCBM27-1 shows the typical beta-sandwich jellyroll fold observed in other CBMs with a single metal ion bound, which was identified as calcium. The crystal structures reveal that the overall fold of CsCBM27-1 remains virtually unchanged upon sugar binding and that binding is mediated by three solvent-exposed tryptophan residues and few direct hydrogen bonds. Based on binding affinity and thermal unfolding experiments this structural calcium is shown to play a role in the thermal stability of CsCBM27-1 at high temperatures. The higher binding affinity of CsCBM27-1 to mannooligosaccharides when compared to other members of CBM family 27 might be explained by the different orientation of the residues forming the "aromatic platform" and by differences in the length of loops. Finally, evidence is presented, on the basis of fold similarities and the retention of the position of conserved motifs and a calcium ion, for the consolidation of related CBM families into a superfamily of CBMs.

Folding and stability of the leucine-rich repeat domain of internalin B from Listeri monocytogenes.

Internalin B (InlB), a surface protein of the human pathogen Listeria monocytogenes, promotes invasion into various host cell types by inducing phagocytosis of the entire bacterium. The N-terminal half of InlB (residues 36-321, InlB321), which is sufficient for this process, contains a central leucine-rich repeat (LRR) domain that is flanked by a small alpha-helical cap and an immunoglobulin (Ig)-like domain. Here we investigated the spectroscopic properties, stability and folding of InlB321 and of a shorter variant lacking the Ig-like domain (InlB248). The circular dichroism spectra of both protein variants in the far ultraviolet region are very similar, with a characteristic minimum found at approximately 200 nm, possibly resulting from the high 3(10)-helical content in the LRR domain. Upon addition of chemical denaturants, both variants unfold in single transitions with unusually high cooperativity that are fully reversible and best described by two-state equilibria. The free energies of GdmCl-induced unfolding determined from transitions at 20 degrees C are 9.9(+/-0.8)kcal/mol for InlB321 and 5.4(+/-0.4)kcal/mol for InlB248. InlB321 is also more stable against thermal denaturation, as observed by scanning calorimetry. This suggests, that the Ig-like domain, which presumably does not directly interact with the host cell receptor during bacterial invasion, plays a critical role for the in vivo stability of InlB.