Poster Presenter

Study of 3D Morphology of Human Blood Erythrocytes by Digital Holographic Microscopy
Tishko T.V., Tishko D.N., Titar V.P.

Cells of a living organism are phase microobjects. Such microobjects almost do not change the intensity of radiation transmitted through them and can be observed using the special methods of classical microscopy: Zernike phase-contrast method and the interference contrast method. But the problem of the 3-D visualization of phase microobjects has not been solved in classical microscopy. 3-D imaging of phase microobjects have been limited to electron microscopy. However, this method is "destructive". Holography opened up new possibilities in microscopy of phase microobjects and resulted in the appearance of holographic analogs of the classical methods, which have some advantages. A combination of holographic microscopy and the methods for digital image processing has led to the new stage in microscopy; and. makes it possible to realize the 3D visualization of phase microobjects. The first digital holographic interference microscope (DHIM), which allows the real-time 3D imaging of phase microobjects and the quantitative measurements of their parameters, has been created at the Laboratory of Holography, Kharkov National University, Ukraine. The results of DHIM study of 3D morphology of blood erythrocytes are presented in this article.

A cell is a unit of a living organism that reflects and determines the status and functioning of the biological system as a whole. The blood cells are of special interest. Blood unites the operation and functioning of all the organs of the living organism. Moreover, blood cell is available for observation as a separate cell of a living organism. The blood erythrocytes are the cells whose main function is the oxygen transport from lungs to tissues and carbon dioxide transport to lungs;they take part in the processes related to maintaining of the blood homeostasis at the organism level. For the optimal functioning the optimal 3D shape of erythrocyte must be realized. The erythrocyte shape must correspond to the maximum surface at the given volume and must ensure deformations providing the erythrocyte motion along thin capillaries. These conditions are satisfied for a biconcave disk shape, which is considered as the medical normal shape. We have determined three main morphological types of erythrocytes: biconcave disk, flat disk, and spherocytes. To characterize the morphological type, a sphericity coefficient k is introduced as a ratio of the erythrocyte thickness at the center to the thickness at half radius. The sphericity coefficient is measured upon the computer processing of the DHIM erythrocyte interferograms.

The DHIM study of the native blood smears shows that erythrocytes exhibit morphological modifications induced by hematological diseases and diseases of different genesises. Our study of ozone-therapy and gamma-radiatiom influence on blood erythrocytes in vivo shows that erythrocytes morphology is sensitive to action of external physical and chemical factors. Thus, it can be concluded that the 3D morphology of blood erythrocytes corresponds to the state of a living organism and its biological response to external factor. We have demonstrated that nonhematological pathologies and external actions cause nonspecific modifications of erythrocytes. The results obtained show that the morphological modifications of erythrocytes, induced by various pathologies and external factors, correspond to an increase in the sphericity coefficient, i.e. to decrease in the erythrocytes surface area. The morphological modifications related to a decrease in the erythrocyte surface area cause a decrease in the functionality with respect to the oxygen supply of tissues and organs. It can lead to different hypoxia pathologies and, hence, a decrease in the organism functionality due to the decrease in the oxygen capacity of blood.