Kardiale Defibrillation durch Laien- und Ersthelfer ?First-Responder”–überlegungen zu einem neuen Rettungskonzept gegen den pl?tzlichen Herztod

Nach wie vor ist die Letalit?t des pl?tzlichen Herztodes, beim Vorliegen von Kammerflimmern oder pulsloser ventrikul?rer Tachykardie, erschreckend hoch. Neue technische M?glichkeiten und das Verst?ndnis neuzeitlicher notfallmedizinischer M?glichkeiten und Hilfeleistung erm?glichen ein optimiertes Behandlungskonzept für Notfallpatienten. Da allein die rasche kardiale Defibrillation die definitive Interventionsm?glichkeit zur Terminierung von Kammerflimmern oder pulsloser ventrikul?rer Tachykardie darstellt, sollte die Anwendung der modernen externen Defibrillationstechnik nicht erst durchgeführt werden, wenn der Notarzt oder das qualifizierte Notfallteam beim Patienten eintrifft. Auch nicht?rztliches Personal und trainierte Laien k?nnen (und dürfen!) diese lebensrettende Ma?nahmen mittels halbautomatischen Defibrillatoren durchführen. Diese M?glichkeiten sollten zu überlegungen und Empfehlungen der Fachverb?nde eingehen, die zu neuen Rettungskonzepten führen.     

Automatic slice tracking in interventional magnetic resonance imaging

Magnetic resonance imaging (MRI) is ideally suited to monitor minimally invasive operations with catheters or needles, since it offers both a superior soft-tissue contrast and the possibility to perform functional tests. In the present study, small radio-frequency coils were attached to the instruments in order to localize the MR-invisible instruments. The implementation of active instrument tracking is described on the basis of the example of active catheter tracking. In this case, the current position information of the instrument is used to automatically position the MRI slice at the catheter location. In combination with a user interface, the interventional radiologist is offered the possibility to perform vascular interventions from within the MR scanner room. At image update rates of approximately 3 Hz, tracking and placement of catheters in vascular structures are possible with interactive switching of slice orientation and image contrast. In an animal model, the technique was successfully used to selectively visualize the abdominal vessels and their branches under MRI guidance.     

A comparison of EMIT and FPIA methods for the detection of cyclosporin A blood levels: does impaired liver function make a difference?

Objective: Apparent cyclosporin A (CSA) blood levels, as determined by fluorescence polarization immunoassay (FPIA) and enzyme-multiplied immunoassay technique (EMIT), were compared in CSA-treated patients with various degrees of liver dysfunction. Methods: FPIA and EMIT were performed in parallel according to test manufacturer instructions in blood from kidney (n=82), liver (n=96) and heart transplant (n=20) patients. Results: The precision of both techniques was greatest in patients with the highest blood levels, and at each blood level greater for the FPIA than for the EMIT. Apparent CSA blood levels, as determined by EMIT, were typically approximately 70% of those determined by FPIA, indicating greater cross-reaction of the antibody in the FPIA with CSA metabolites. However, the ratio of values determined with EMIT and FPIA was very similar in kidney, liver and heart transplant patients. Among liver transplant patients it was also very similar in those without major alterations of hepatic function and in those with impaired excretory (increased bilirubin and γGT) or synthetic (i.e., reduced thromboplastin time) function. Extended storage of blood samples for up to 10 days did not affect apparent CSA blood level estimates by EMIT in a clinically relevant manner. Conclusions: We conclude that the greater specificity of the antibody in the EMIT for the CSA parent compound does not translate into a clinically relevant advantage for CSA monitoring. Received: 20 September 1996 / Accepted in revised form: 17 February 1997     

The voltage dependence of membrane capacity.

1. Membrane capacity of sartorius muscle fibres has been measured at membrane potentials between -200 and +50 mV. Within this potential range the capacity is not independent of potential. Dielectric saturation is present at large negative and at positive internal potentials, indicating the presence in the membrane of permanent dipoles or movable charges. 2. In normally polarized fibres there is a sharp peak in the capacity-potential relation of about -50 mV; the capacity at this peak is 50% larger than the capacity at -90 mV. 3. In depolarized fibres this sharp peak of capacity is not present. Over the range -200 to +50 mV the capacity variation is about 10% with a broad maximum at about -80 mV. 4. The dielectric behaviour of muscle membrane is most simply explained by postulating two species of permanent dipoles or mobile charges: Charge 1 present in normally polarized fibres, but neutralized or immobilized in depolarized fibres; Charge 2 present in both polarized and depolarized fibres. The distribution of Charge 1 is more steeply voltage-dependent than is the distribution of Charge 2. 5. Movement of Charge 1 from one fully saturated configuration to the other involves a charge transfer across the membrane of between 20 and 30 nC/muF. Movement of Charge 2 in depolarized fibres requires a similar transfer of charge.     

Eine neue synthese von polyäther-ketonen

Nitro-substituents in the p-positions of benzophenone derivatives were activated to react with alkali-bisphenolates in polar aprotic solvents to, e.g. dimethylsulfoxide, in a nucleophilie reaction to split off alkali nitrite and yield linear, high molecular weight polyether ketones. Optimum reaction conditions for the polycondensation are found out from the reaction of low molecular model compounds.     

Lung ventilation‐ and perfusion‐weighted Fourier decomposition magnetic resonance imaging: In vivo validation with hyperpolarized 3He and dynamic contrast‐enhanced MRI

The purpose of this work was to validate ventilation‐weighted (VW) and perfusion‐weighted (QW) Fourier decomposition (FD) magnetic resonance imaging (MRI) with hyperpolarized ³He MRI and dynamic contrast‐enhanced perfusion (DCE) MRI in a controlled animal experiment. Three healthy pigs were studied on 1.5‐T MR scanner. For FD MRI, the VW and QW images were obtained by postprocessing of time‐resolved lung image sets. DCE acquisitions were performed immediately after contrast agent injection. ³He MRI data were acquired following the administration of hyperpolarized helium and nitrogen mixture. After baseline MR scans, pulmonary embolism was artificially produced. FD MRI and DCE MRI perfusion measurements were repeated. Subsequently, atelectasis and air trapping were induced, which followed with FD MRI and ³He MRI ventilation measurements. Distributions of signal intensities in healthy and pathologic lung tissue were compared by statistical analysis. Images acquired using FD, ³He, and DCE MRI in all animals before the interventional procedure showed homogeneous ventilation and perfusion. Functional defects were detected by all MRI techniques at identical anatomical locations. Signal intensity in VW and QW images was significantly lower in pathological than in healthy lung parenchyma. The study has shown usefulness of FD MRI as an alternative, noninvasive, and easily implementable technique for the assessment of acute changes in lung function. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.     

Monitoring molecular, functional and morphologic aspects of bone metastases using non-invasive imaging

Bone is among the most common locations of metastasis and therefore represents an important clinical target for diagnostic follow-up in cancer patients. In the pathogenesis of bone metastases, disseminated tumor cells proliferating in bone interact with the local microenvironment stimulating or inhibiting osteoclast and osteoblast activity. Non-invasive imaging methods monitor molecular, functional and morphologic changes in both compartments of these skeletal lesions - the bone and the soft tissue tumor compartment. In the bone compartment, morphologic information on skeletal destruction is assessed by computed tomography (CT) and radiography. Pathogenic processes of osteoclast and osteoblast activity, however, can be imaged using optical imaging, positron emission tomography (PET), single photon emission CT (SPECT) and skeletal scintigraphy. Accordingly, conventional magnetic resonance imaging (MRI) and CT as well as diffusion- weighted MRI and optical imaging are used to assess morphologic aspects on the macroscopic and cellular level of the soft tissue tumor compartment. Imaging methods such as PET, MR spectroscopy, dynamic contrast-enhanced techniques and vessel size imaging further elucidate on pathogenic processes in this compartment including information on metabolism and vascularization. By monitoring these aspects in bone lesions, new insights in the pathogenesis of skeletal metastases can be gained. In translation to the clinical situation, these novel methods for the monitoring of bone metastases might be applied in patients to improve follow-up of these lesions, in particular after therapeutic intervention. This review summarizes established and experimental imaging techniques for the monitoring of tumor and bone cell activity including molecular, functional and morphological aspects in bone metastases.