XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
220
T2: P–5
Estimation of dielectric parameters of red blood cell membranes by
microwave dielectrometry: early diagnostics and treatment control for
ischemic stroke patients
Liliya Batyuk
1
, Dmitriy Astapovich
2
, Vladimir Berest
2
, and Nataliya Kizilova
3,4
1
Department of Medical and Biological Physics and Medical Information Science, Kharkiv National
Medical University, 4 Nauky Avenue, Kharkiv, 61022, Ukraine, e-mail: liliya-batyuk@ukr.net
2
Department of Molecular and Medical biophysics, Kharkiv V. N. Karazin Kharkiv National
University, 4 Svobody Sq., Kharkiv, 61022, Ukraine
3
Institute of Aeronautics and Applied Mechanics, Warsaw University of Technology, Warsaw, Poland
4
Institute of Mechanical Science, Vilnius Gediminas Technical University, Vilnius, Lithuania
Stroke is one of the leading causes of morbidity and mortality in the world [1]. In vitro
measurement of the dielectric parameters of blood and their dynamical changes makes it
possible to evaluate the severity of the stroke ischemia and success of the prescribed therapy, as
well as identify patients with a probable unfavourable prognosis. In this study the dielectric
parameters of suspensions of the red blood cells (RBC) and their ghosts taken from the blood
samples of the patients with ischemic stroke have been determined in vitro by the ultra high
frequency (UHF) dielectrometry [2] at the operating frequency f = 9.2 GHz. Blood samples of
fifteen donors and twenty patients with acute ischemic stroke have been collected and incubated
with heparin. RBC have been washed out with saline in the centrifuge at ω = 3500 min
–1
and the
RBC suspensions have been used for measurements of the real ε’ and imaginary ε” parts of the
complex dielectric permittivity ε = ε’ + iε” in the UHF dielectrometer. The suspensions of RBC
ghosts have been prepared by chemical haemolysis. The preliminary diagnosis for each patient
was formulated on the basis of the generally accepted European recommendations for the
prevention and treatment of ischemic stroke [3, 4].
Detailed statistical analysis of the measurement data revealed that ε’ of both RBC
suspensions and RBC membranes in patients with ischemic stroke tended to increase after the
treatment in comparison with the corresponding indicators of both suspensions and membranes
before the treatment. It was also found that the average values of the static dielectric constant
(ε
s
) of the RBC membranes of the patients with ischemic stroke decreased after the treatment, as
well as the average values of frequency dielectric relaxation of water molecules (ƒ
D
) of RBC
suspensions and RBC membranes.
Therefore, a decrease in the real part of the erythrocyte suspensions and membranes and an
increase in ε
s
and ƒ
D
may be used as early and reliable indexes of the acute ischemic state. After
the treatment all the parameters normalized; therefore, the proposed method can be used for
control over the treatment and prognosis of its success. The method is simple and universal; it
needs a small amount of the venous blood and standard laboratory preparation of the probe for
the UHF dielectrometry study.
Keywords: microwave dielectrometry; dielectric permittivity; red blood cells; acute ischemic disorders
References
[1] A.D. Lopez, C.D. Mathers, M. Ezzati, D.T. Jamison, C.J. Murray, Lancet 367 (2006) 1747.
[2] S.V. Gatash, Radiophysics and Electronics 4(1) (1999) 129.
[3] Recommendations for Stroke Management: Update 2003. European Stroke Initiative (EUSI):
Cerebrovascular Diseases, 2004: 17 (suppl 2), pp. 1.
[4] T. Kjellstrom, B. Norrving, A. Shatchkute, Cerebrovasc. Dis. 23 (2007) 231.
XIV
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International Conference on Molecular Spectroscopy, Białka Tatrzańska 2017
221
T2: P–6
Taurine hydration – a spectroscopic approach
Barnaba Piotrowski
1
, Aneta Panuszko
1
, Sebastian Demkowicz
2
, and Janusz Stangret
1
1
Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology,
Narutowicza 11/12, 80-233 Gdańsk, Poland, e-mail: aneta.panuszko@pg.gda.pl
2
Department of Organic Chemistry, Chemical Faculty, Gdańsk University of Technology,
Narutowicza 11/12, 80-233 Gdańsk, Poland
Taurine, an unusual amino acid with a sulfonic group in place of a carboxyl group, is
included in a category of compounds called osmolytes, which are used by cells of living
organisms for osmoregulation. Due to its cytoprotective properties, such as the ability to
safeguard cells from the consequences of Ca
2+
overload and oxidative stress, taurine is qualified
as a stabilizing osmolyte [1]. Studies confirm its stabilizing influence on the native structure of
proteins [2, 3]. Despite significant advances in understanding the effect of osmolytes on protein
stability, the mechanism of this stabilization is not clear. One of the postulated theories assumes
that osmolytes do not interact with proteins directly, rather interact through the surrounding
water, modifying its properties [4, 5]. Thus, to understand the effect of osmolytes on protein
stability it is important to understand their influence on the water structure and interactions
between water molecules.
FTIR vibrational spectroscopy was used to study taurine’s effect on water. The stretching
band ν
OD
of the HDO molecule, isotopically diluted in H
2
O, was utilized as a molecular probe of
interactions in taurine solutions. Spectral data was analyzed using the difference spectra method,
which leads to the isolation of the spectrum of the solvent affected by the solute and therefore
also the structural and energetic state of taurine-affected water molecules [6].
Optimal structures of small water clusters of taurine calculated utilizing density functional
theory (DFT) within the polarizable continuum model (PCM) were useful in the interpretation of
the experimental results. Comparison of results coming from the analysis of vibrational spectra
of solutions and calculations is made possible through a known experimental equation
correlating interatomic distances O···O between water molecules with OD stretching
frequencies of the HDO molecule.
Keywords: taurine; osmolytes; water structure; difference spectra method; FT-IR spectroscopy
Acknowledgment
This work was supported by the Polish National Science Center (NCN) based on decision No. DEC-
2013/11/B/NZ1/02258. Calculations were performed at the Academic Computer Centre in Gdańsk (TASK).
References
[1] S. W. Schaffer, C. Ju Jong, R. KC, J. Azuma, J. Biomed. Sci. 17 (2010) S2.
[2] T. Arakawa, S. N. Timasheff, Biophys. J., 47 (1985) 411.
[3] S. Pieraccini, L. Burgi, A. Genoni, A. Benedusi, M. Sironi, Chem. Phys. Lett. 438 (2007) 298.
[4] P. Yancey, M. Clark, S. Hand, R. Bowlus, G. Somero, Science 217 (1982) 1214.
[5] P. Bruździak, A. Panuszko, J. Stangret, J. Phys. Chem. B 117 (2013) 11502.
[6] M. Śmiechowski, J. Stangret, Pure Appl. Chem. 82 (2010) 1869.
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