Off-patient assessment of pre-cordial impact mechanics among medical professionals in North-East Italy involved in emergency cardiac resuscitation.
Pellis, T., Pausler, D., Gaiarin, M., Franceschino, E., Epstein, A., Boulin, C. & Kohl, P.
Prog Biophys Mol Biol. 2012 Oct;110(2-3):390-6. doi:10.1016/j.pbiomolbio.2012.08.002. Epub 2012 Aug 11.
Pre-cordial thump (PT) relies on cardiac mechano-electric transduction to transform mechanically-delivered energy into an electrophysiologically relevant stimulus. Its use for emergency resuscitation has declined recent years, amidst concerns about effectiveness and side-effects. In addition, there is insufficient knowledge about bio-mechanical properties and mechanisms of PT. Using a PT-mechanics recorder, we measured PT off-patient among healthcare professionals (n = 58) in North-East Italy, and related this to retrospective information on self-reported PT outcomes. Impact-speed and peak-force were 4.7 +/- 1.3 m s(-1) (2.2-7.8 m s(-1)) and 394 +/- 110 N (202-648 N), respectively. Average self-reported cardioversion rate by PT was 35%. No adverse events were stated. All but 3 of PT providers with self-reported cardioversion rates >/=50% had pre-impact fist-speeds of >/=3.7 m s(-1). In comparison with previously-reported data from UK and US (n = 22 each), self-reported success-rates and pre-impact fist-speeds were more similar to US (PT-induced cardioversion rate 27.7%; fist-speed 4.17 +/- 1.68 m s(-1)) than to UK participants (PT-induced cardioversion rate 13.3%; fist-speed 1.55 +/- 0.68 m s(-1)). Small cohort-size, retrospective nature of data-gathering, and 'self-selection bias' (participants who have used PT on patients) limits the extent to which firm conclusions can be drawn. Observations are compatible, though, with the possibility that pre-impact fist-speed may affect success-rate of PT. Thus, where PT is used for acute resuscitation, it is delivered because it is immediately 'at hand'. Negative side effects are rare or absent in witnessed cardiac arrest cases. Pre-impact fist-speed may be a determinant of outcome, and this could be trained using devices suitable for self-assessment.
Soft tissue impact characterisation kit (STICK) for ex situ investigation of heart rhythm responses to acute mechanical stimulation.
Cooper, P.J., Epstein, A., Macleod, I.A., Schaaf, S.T., Sheldon, J., Boulin, C. & Kohl, P.
Prog Biophys Mol Biol. 2006 Jan-Apr;90(1-3):444-68. Epub 2005 Aug 9.
Both mechanical induction and mechanical termination of arrhythmias have been reported in man. Examples include pre-cordial impacts by sports implements (baseballs, pucks) that can trigger arrhythmias, including ventricular fibrillation, or via the so-called pre-cordial thump, used as an emergency resuscitation measure to convert arrhythmias to normal sinus node rhythm. These interventions have been partially reproduced in experimental studies on whole animals. Relating observations at the system's level to underlying mechanisms has been difficult, however, largely because of: (i) a deficit in efficient and affordable pharmacological agents to selectively target (sub-)cellular responses in whole animal studies, and (ii) the lack of suitable experimental models to study the above responses at intermediate levels of functional and structural integration, such as the isolated heart or cardiac tissue. This paper presents a soft tissue impact characterisation kit (STICK), suitable for quantitative investigations into the effects of acute mechanical stimulation on cardiac electro-mechanical function in rodent isolated heart or tissue preparations. The STICK offers independent control over a range of relevant biophysical parameters, such as impact location and energy, pre-impact projectile speed and contact area, as well as over the timing of a mechanical stimulus relative to the cardiac cycle (monitored via electrocardiogram, ECG, here recorded directly from the cardiac surface). Projectile deceleration upon interaction with the tissue is monitored, contact-free, with a resolution of 175 microm, providing information on tissue deformation dynamics, force, pressure and work of the mechanical intervention. In order to study functional effects of cardiac mechanical stimulation in the absence of tissue damage, impacts must be limited (for juvenile Guinea pig heart) to 2-2.5 mJ in the slack left ventricle (diastolic impact) and 5-10 mJ in contracture (systolic impact), as confirmed by enzyme assay and histological investigation. Impacts, timed to coincide with the early T-wave of the ECG, are capable of triggering short runs of ventricular fibrillation. Thus, the STICK is a suitable tool for the study of acute cardiac mechano-electric feedback effects, caused by short impulse-like mechanical stimulation, at the level of the isolated organ or tissue.
Automatisierte DNA-Extraktion durch Kombination von Liquid Handling und
Zimmermann, J., Zinn, T., Benes, V., Ibberson, D., Boulin, C., Griebel, R., Lomax, P., Mausel, M., Schubell, U. & Gunther-Eberle, K.
Laborwelt 2003 4(5) 41-42
The Parallel Hough-Transform Systolic Array ASIC.
Epstein, A., Paul, G.U., Vettermann, B., Boulin, C. & Klefenz, F.
IEEE Trans. on Nuclear Science 2002 49(2) 339-346
The PASERO Project: Parallel and Serial Readout systems for gas proportional synchrotron radiation X-ray detectors.
Koch, M.H.J., Boulin, C., Briquet-Laugier, B., Epstein A., Sheldon, S., Beloeuvre, E., Gabriel, A., Herve, C., Kocsis, M., Koschuch, A., Laggner, P., Leingartner, W., de Raad Iseli, C., Reimann, T., Golding, F. & Torki, K.
Nuclear Instrum. and Methods 2001 (A467-468) 1156-1159
A data acquisition system for gas proportional detectors with delay line readout based on space-time-space conversion.
de Raad Iseli, C., Reimann, T., Golding, G., Boulin, C., Epstein, A., Beloeuvre, E., Gabriel, A. and Koch & M.H.J.
Nuclear Instrum. Methods 2001 (A467-468) 1152-1155
Fast wire per wire X-ray data acquisition system for time resolved small angle scattering experiments
Epstein, A., Briquet-Laugier, F., Sheldon, S. & Boulin, C.
Proc. XIth IEEE Real Time Conference 1999 316-321
General purpose RISC based unit: a building block for fast data acquisition systems.
Epstein, A. & Boulin, C.
Proc. XIth IEEE Real Time Conference 1999 313-315
Real-time software for a wire per wire parallel readout X-ray data acquisition system.
Briquet-Laugier, F., Baumlin, P., Boulin, C., Golding, F., Koch, M.H.J & Epstein, A.
Proc. XIth IEEE Real Time Conference 1999 129-133
A role for microtubule dynamics in phagosome movement.
Blocker, A., Griffiths, G., Olivo, J.C., Hyman, A.A. & Severin, F.F.
J Cell Sci 1998 Feb 111 ( Pt 3) 303-312
We have shown previously that intracellular phagosome movement requires microtubules. Here we provide evidence that within cells phagosomes display two different kinds of microtubule-based movements in approximately equal proportions. The first type occurs predominantly in the cell periphery, often shortly after the phagosome is formed, and at speeds below 0.1 microm/second. The second is faster (0.2-1.5 micron/second) and occurs mainly after phagosomes have reached the cell interior. Treating cells with nanomolar concentrations of taxol or nocodazole alters microtubule dynamics without affecting either total polymer mass or microtubule organisation. Such treatments slow the accumulation of phagosomes in the perinuclear region and reduce the number of slow movements by up to 50% without affecting the frequency of fast movements. This suggests that a proportion of slow movements are mediated by microtubule dynamics while fast movements are powered by microtubule motors. In macrophages, interphase microtubules radiate from the microtubule organising centre with their plus-end towards the cell periphery. To understand the behaviour of 'early' phagosomes at the cell periphery we investigated their ability to bind microtubule plus-ends in vitro. We show that early phagosomes have a strong preference for microtubule plus-ends, whereas 'late' phagosomes do not, and that plus-end affinity requires the presence of microtubule- associated proteins within cytosol. We suggest that phagosomes can bind to the plus-ends of dynamic microtubules and move by following their shrinkage or growth.
A RISC based SCSI interface for a protein crystallography detector.
Epstein, A., Baumlin, P. & Boulin, C.
IEEE Trans. on Nuclear Science 1998 45(4) 1934-1936
A fast position encoding system for delay line based gas filled area detector.
Epstein, A. & Boulin, C.
IEEE Trans. on Nucl. Science 1998 45 1931-1933
A fully automated image acquisition and analysis system for low light level fluorescence microscopy.
Herr, S., Bastian, T., Pepperkok, R., Boulin, C. & Ansorge, W.
Meth Mol Cell Biol 1994 4 164-170