Bogdan IORGA

University of Cologne, Institute of Vegetative Physiology, Cologne, .

E-mail: trimite un mesaj.

Pagina web a instituţiei: http://www.uni-koeln.de/med-fak/physiologie/vp/index.htm

Nascut(a) in: 1972

Interese: biofizica, miofibrile, cardiomiocite, modularea contractiei musculare, cinetica, sisteme contractile, cardiomiopatie, maladie musculara

Detalii:
Gradul de doctor obtinut in 2004: "Mechanochemical coupling in skeletal myofibrils"
http://www.sfbiophys.org/resumeIORGA.html

Domenii de interes:
- Biofizica, cinetica si biochimia sistemelor contractile striate
- Tehnici si metode utilizate in studiul contractiei si dinamicii miofibrilelor
- Biofizica moleculara si patologia miocardului

Metode si protocoale:
- Competenta in tehnologia miofibrilara
- Isolarea miofibrilelor din biopsii ale muschiului skeletic sau cardiac
- Biofizica, cinetica si biochimia sistemelor actina-miozina

Tehnici de cinetici rapide:
- Specializare in tehnicile de masurare a cineticilor de forta la nivelul molecular si subcelular bazate pe principiul video-microscopiei de forta atomica si pe tehnologia de schimbare rapida a fluxurilor de solutii (Spitalul Universitar din Köln, Germania)
- Analiza sinusoidala ca metoda a micilor perturbatii utilizata in explorarea cuplajului mecano-chimic in contractia miofibrilara (colab. Universitatea Iowa, SUA)
- Rapid-Flow-Quench (INSERM, Montpellier, Franta si Hi-Tech, Salisbury, Marea Britanie)
- Stopped-Flow (Hi-Tech, Salisbury, Marea Britanie si Bio-Logic, Franta)
- Time-Resolved Pulsed Spectrofluorimetry pentru masurarea timpilor de viata a starilor excitate (Edinburgh, Marea Britanie)

Tehnici de microscopie:
- Video-microscopie optica de fluorescenta
- Microscopie optica in contrast de faza si analiza Fourier a densitatilor optice ale sarcomerelor in masurarea vitezei de contractie a miofibrilelor utilizand sistemul SARCO (INSERM, Montpellier, Franta)
- Video-microscopie (bright field, contrast de faza) in studiul dinamicii sarcomerelor

Spectrofotometrie:
- Studii spectrofotometrice pentru procesele de pliere-depliere in proteine
- Studii spectrofotometrice pentru studiul proceselor de transfer energetic intermolecular
- Metode cinetice utilizand sisteme enzimatice cuplate

Proiecte in derulare:
1. Caracterizarea functionala a sistemelor contractile continant mutatii asociate cardiomiopatiilor in proteinele sarcomerice (DFG SFB12-A2/070021/2005-2012, Centrul pentru Medicina Moleculara Köln TV91/2005-2010).
2. Investigatiile functionale si biochimice ale miofibrilelor izolate din ventriculul drept al miocardului pacientilor prezentand maladia Tetralogia lui Fallot (Köln-Fortune 109/2007-2008, Spitalul Universitar Köln).

Details:
PhD degree in 2004: "Mechanochemical coupling in skeletal myofibrils"
http://www.sfbiophys.org/resumeIORGA.html

Fileds of interests:
- Biophysics, kinetics and biochemistry of the striated contractile systems
- Techniques and methods used to study the myofibrillar contraction and dynamics
- Molecular biophysics and the pathology of the myocardium
- Functional and biophysical characterization of cardiac myofibrils isolated from different genetically controlled models: zebrafish, engineered cardiac muscular tissues, cardiomyocytes diferentiated from embrionic or induced pluripotent stem cells

Methods and protocols:
- Expertise in myofibrillar technology
- Myofibrils preparation starting from biopsies of skeletal and cardiac muscles
- Biophysics, kinetics and biochemistry of the actin-myosin systems

Rapid kinetics techniques:
- Experimental expertise in force kinetics measurements at subcellular levels based on the atomic force video-microscopy and the fast solution flows switch technology (University of Cologne, Germany)
- Sinusoidal analysis as a low perturbational method to explore mechanochemical coupling in contracting myofibrils (University of Cologne, Germany and Iowa University, USA)
- Rapid-Flow-Quench (INSERM, Montpellier, France and Hi-Tech, Salisbury, UK)
- Stopped-Flow (Hi-Tech, Salisbury, UK and Bio-Logic, France)
- Time-Resolved Pulsed Spectrofluorimetry for life-time measurements (Edinburgh, UK)

Microscopy techniques:
- Optical fluorescence video-microscopy for the study of sarcomere dynamics
- Optical microscopy in phase contrast and Fourier analysis of the optical density of the sarcomeres for shortening velocity measurements of the myofibrils using SARCO system

Spectrophotometry:
- Spectrophotometrical studies of the protein folding-unfolding processes
- Spectrophotometrical studies of the intermolecular energy transfer
- Kinetical methods using enzymatic coupled systems

Present research activity:
1. Functional characterization of contractile systems containing cardiomyopathy associated mutations in sarcomeric proteins (Deutsche Forschungsgemeinschaft SFB12-A2/070021/2005-2012, Center for Molecular Medicine Cologne TV91/2005-2010).
2. Functional and biochemical investigations of myofibrils isolated from the right ventricle of the myocardium of the patients with the Tetralogy of Fallot (Koeln-Fortune 109/2007-2008, University Hospital Cologne).

Publicații selectate:

* Iorga B., Neacsu C.D., Neiss W.F., Wagener R., Paulsson M., Stehle R., Pfitzer G., Micromechanical function of myofibrils isolated from skeletal and cardiac muscles of the zebrafish, The Journal of General Physiology, 137 (3), 2011.

* Stehle R, Iorga B., Kinetics of cardiac sarcomeric processes and rate-limiting steps in contraction and relaxation, Elsevier, J Mol Cell Cardiol, 48(5), 2010.

* Stehle R., Solzin J., Iorga B., Poggesi C., Insights into the kinetics of Ca(2+)-regulated contraction and relaxation from myofibril studies, Springer-Verlag, Pflugers Arch - Eur J Physiol, DOI 10.1007/s00424-008-0630-2, 2009.

* Iorga B., Blaudeck N., Solzin J., Neulen A., Stehle I., Lopez Davila A. J., Pfitzer G. and Stehle R., Lys184 deletion in troponin I impairs relaxation kinetics and induces hypercontractility in murine cardiac myofibrils, Cardiovasc Res, 77(4), 2008.

* Solzin J., Iorga B., Sierakowski E., Gomez Alcazar D. P., Ruess D. F., Kubacki T., Zittrich S., Blaudeck N., Pfitzer G. and Stehle R., Kinetic mechanism of the Ca2+-dependent switch-on and switch-off of cardiac troponin in myofibrils, Biophys J, 93(11), 2007.

* Stehle R., Iorga B. and Pfitzer G., Calcium regulation of troponin and its role in the dynamics of contraction and relaxation, Am J Physiol Regul Integr Comp Physiol, 292(3), 2007.

* Stehle R., Solzin J., Iorga B., Gomez D., Blaudeck N. and Pfitzer G., Mechanical properties of sarcomeres during cardiac myofibrillar relaxation: stretch-induced cross-bridge detachment contributes to early diastolic filling, J Muscle Res Cell Motil, 27(5-7), 2006.

* Iorga B., Adamek N. and Geeves M. A., The slow skeletal muscle isoform of myosin shows kinetic features common to smooth and non-muscle myosins, J Biol Chem, 282(6), 2007.

* Roels B., Reggiani C., Reboul C., Lionne C., Iorga B., Obert P., Tanguy S., Gibault A., Jougla A., Travers F., Millet G. P. and Candau R, Paradoxical effects of endurance training and chronic hypoxia on myofibrillar ATPase activity, Am J Physiol Regul Integr Comp Physiol, in press, 2008.

* Iorga B., Candau R., Travers F., Barman T. and Lionne C., Does phosphate release limit the ATPases of soleus myofibrils? Evidence that (A)M. ADP.Pi states predominate on the cross-bridge cycle, J Muscle Res Cell Motil, 25(4-5), 2004.

* Lionne C., Iorga B., Candau R. and Travers F., Why choose myofibrils to study muscle myosin ATPase?, J Muscle Res Cell Motil, 24(2-3), 2003.

* Candau R., Iorga B., Travers F., Barman T. and Lionne C., At physiological temperatures the ATPase rates of shortening soleus and psoas myofibrils are similar, Biophys J, 85(5), 2003.

* Lionne C., Iorga B., Candau R., Piroddi N., Webb M. R., Belus A., Travers F. and Barman T., Evidence that phosphate release is the rate-limiting step on the overall ATPase of psoas myofibrils prevented from shortening by chemical cross-linking, Biochemistry, 41(44), 2002.

* Semenescu G., Cioaca C., Iorga B. and Gughea G., Phenonenological considerations rely on the double mixed electric layer model at the electrode-electrolyte interface, Acta Chimica Slovenica, 49, 2002.

* Semenescu G., Cioaca C., Iorga B. and Gughea G., Mediator role of some organic substances in the charge transfer on metal-electrolyte interface, Acta Chimica Slovenica, 49, 2002.

* Semenescu G., Cioaca C. and Iorga B., A new phenomenological model describing conduction in electrolyte solutions, Acta Chimica Slovenica, 47, 2000.

* Gazdaru D. M. and Iorga B., Spectrophotometric analysis of the mixtures of photosynthetic pigments, Journal of Optoelectronics and Advanced Materials, 4(1), 2002.

* Gazdaru D. M. and Iorga B., Characterization of the quenching of chlorophyll a fluorescence by beta-carotene using the non-linear analysis, Photosynthetica, 39(4), 2001.

* Gazdaru D. M., Iorga B. and Balan P. F., Quenching of the chlorophyll-a fluorescence by beta-carotene, G. Garab, Kluwer Academic Publishers, Dordrecht, (Nedherland), Photosynthesis: Mechanism and effects., 1, 1998.