Ekateryna I. Galanzha

Skin backreflectance and microvascular system functioning at the action of osmotic agents

The in vivo back reflectance spectra of rat skin were measured by inter-dermal injection of glycerol and glucose solutions. The injection of glycerol solution caused a significant decrease in skin reflectance within the first few minutes, and the decreased reflectance was conserved for a long time period. The effect of glucose solution on skin optical clearing was also demonstrated. The decrease of reflectance was stronger than at glycerol injection but was conserved for a shorter period. For hyperosmotic solutions of glucose and glycerol the optical clearing of skin was coupled with stasis and dilation of microvessels in the area of application of the agent. To study the peculiarities of the blood microcirculation system the rat mesentery was used as an animal model. The effect of each agent on blood microcirculation had some distinctive features.

Investigation of statistical properties of lymph-flow dynamics using speckle microscopy

At different pathological stages, the changes both of blood and lymph microcirculation parameters are observed. These parameters are of great importance in diagnostics. The type of these changes may indicate both the kind and the degree of disease. Investigation of the behavior of dynamic characteristics of these flows at different stages is of special interest. In this paper the peculiarities both of blood and lymph motion have been considered. The further development of speckle-interferometrical method has been carried out for the investigation of the dynamic characteristics of blood and lymph flows in microvessels. Analysis of two dynamic parameters which had been introduced in previous papers concerning this problem, is made in this paper. The influence of lymphotropic agent both on lymph flow and its dynamic characteristics is also discussed.

Comparison of lymph and blood flow in microvessels: coherent optical measurements

In the present study the characteristics of blood and lymph microcirculation are investigated. The microcirculation was studied on small intestine mesentery in norm and during NG-nitro-L-arginine (L- NNA) application. The direct measurement of lymph flow velocity (parameter V) in individual microvessels was based on the technique of light intravital videomicroscopy. The first spectral moments of Doppler signal characterizing the mean velocities of lymph and blood flow in microvessels (parameters M1L and M1B) were measured by speckle- interferometrical method. Simultaneously, diameters of blood and lymph microvessels as well as parameters of phasic contractions and valve function of lymphatics were registered. The mean diamters of investigated lymphatics and venules were 170±20 μm and 8±0.5 μm, correspondingly. In 24% of lymph microvessels phasic contractions were observed. The mean flow velocity in blood microvessels was 10 times more than the one in lymphatics. L-NNA application led to variable effects on diameter of lymphatics, increased the number of microvessels with phasic contractions and modified parameters of these contractions. The mean velocity of lymph flow (V) was increased. The mean value of M1L was not changed; the M1L maximum in 75% of the lymphatics was increased. In 88% of venules M1B was decreased on 25±7%.

Development imaging and experimental model for studying pathogenesis and treatment efficacy of postmastectomy lymphedema

The experimental model was created during an abdominal dissection of the rat mesentery and ligation of the collecting vein of mesentery. It was found that mesentery edema was developed for 20-30 min. Simultaneously monitoring of main the parameters of blood and lymph flow revealed significant increasing of interstitial water amount (up to 3 times), reduction of blood microcirculation, increasing of blood vessels permeability, decreasing of lymph microvessels diameter, phasics contractions, and lymph flow velocity.

The diagnosis of lymph microcirculation in experimental studies on rat mesentery in vivo

The many biological and medical problems associated with microlymphatic functioning and its disturbances at different diseases, include primary and secondary lymphedema, inflammation, lymphatic malformations, and so on. It is important both to establish an adequate animal model for study lymph microcirculation in vivo and to match it with corresponding diagnostic techniques. The rat mesentery has been successfully used in experiments focusing on the microcirculation, including small lymphatics. Among optical methods the transmittance microscopy is most widely employed to study microcirculation. We have undertaken following investigations: development and evaluation of capability of transmission microscopy for in vivo studies of microcirculation; obtaining of single cell images; estimation of lymph microcirculation parameters, including the relation of forward to backward flow in intact lymphatics; regulation of microlymphatic function by nitric oxide and study of microlymphatic disturbances at the experimental lymphedema. Although interesting data has been obtained, the transmission microscopy has the relatively low absorption sensitivity and prevents obtaining good absorption contrast. To obtain more comprehensive physiological data, the further development and improvement imaging of rat mesentery is discussed with focus on new combined optical imaging systems which integrate recent advances in video-transmission and photothermal (PT) microscopy, PT fluid velocimetry, and laser spectroscopy.

Special training laboratory on optical biophysics: coherent-domain methods in biomedicine

The set of optically united practical works on coherent- domain methods in biomedicine of the special training laboratory on optical biophysics for the undergraduate and postgraduate students specialized in biophysics, biochemical physics and medical physics is described.

Laser speckle flow velocity sensor for functional biomicroscopy

Laser speckle based direction sensitive flow velocity sensor has been developed for use with transmission microscope for in vivo bioflow monitoring. The instrument allows for measurements of blood and lymph flow parameters in micro vessels simultaneously with biomicroscopic measurements. The performance of the instrument was tested using the model of lymph micro vessel and was illustrated by the results of in vivo experiments on micro vessels of rat mesentery.

Effects of different doses of glucose on scattering properties of skin

In this study the action of different doses of glucose solution on scattering properties of skin in vivo have been investigated. The application of glucose as hyperosmotic agent leads to the significant increasing of the tissue optical transmittance. There are dose dependent and time dependent effects of glucose on the skin reflectance. The good clearing of tissue is given after undercutaneous administration of 40 percent and 35 percent glucose solutions. The application of such doses of glucose allows one to visualize the small blood vessels in rat skin. The optimal interval of time for the clearing of rat skin is 15 minutes after injection. The method of clearing tissue is conventient, cheap and simple for The diagnostic of microcirculation of skin in vivo.

In-vivo lymph dynamic monitoring using speckle-correlation technique and light microscopy

In this work we described the new modification of experimental setup designed on the basis of transmission microscopy and high-resolution speckle-correlation technique. This combined technique provides the simultaneous speckle and video registration of lymph dynamics that allows one to calibrate the speckle-correlation velocity sensor and to determine an absolute flow velocity and its direction. As a result many parameters of lymph dynamic were measured quickly, conveniently and simultaneously and a new data about the lymph flow velocity and other functions of microcirculation were received. The results of the experimental study of lymph microcirculation in small intestine mesentery of rat in vivo are presented.

Optical properties of lymph flow in single microvessels: biomicroscopic, speckle-interferometric, and spectroscopic measurements

The lymph flow diagnostics in microvessels of rat mesentery were performed using light biomicroscopy, speckle- interferometry and spectroscopy. By light microscopy method we have got the dynamic of microvessels images in real time and registered phasic contractions and valve function of lymphatics, lymph and blood flow. The mean velocity of lymph flow was the highest at the moderate number of lymphocytes in flow. We had found the close links between phasic contractions, valve activity and lymph flow intensity. The high-resolution speckle-microscopy quickly gives much information about average lymph flow velocity, but only the relative value of velocity can be estimated. The phasic contractions cause the changes of the speckle signals and led to the modification of lymph flow in microvessels. The reflectance spectra characterize functional state of lymphatics and lymph flow in microvessels.