თამაზ სულაბერიძე

This paper presents segmentation method of extraction 3D segments on scene digital image based on non-parametric statistical estimation of probability density function. Definitions of the modes, both the centers and the radiuses of sameness as greatest boundary of detected clusters are given. The concepts of clusters and connectivity for digital image are suggested. The method does not require initial classification of the data and supposed number of clusters. Execution of the segmentation procedure does not require an interactive entry of parameters based on heuristics. The statistical procedure of adequate selection of mathematical model is developed.

The aim of present work is to explore the influence of extremely low-frequency electromagnetic fields (8.34 and 217 Hz) utilized in cell phones on habituation of the mollusk single neuron to intracellular stimuli. The isolated nervous system of the mollusk Helix Pomatia was used in the experiments. Helmholtz coils were used to expose brain ganglia to the low-frequency electromagnetic fields. Peak values of the extremely low-frequency fields were between 1 and 6 mT. Neuron electrophysiology was investigated using a standard microelectrode technique. Exposure of the neuron to the low-frequency electromagnetic fields caused dehabituation to intracellular stimulus. The effect was proportional to the magnetic induction peak value. The observed dehabituation occurs by degradation of the signal to noise ratio and by alteration of the neuron's normal function.

The goal of the present work was to explore the influence of commercially available cell phone irradiation on the single neuron excitability and memory processes. A Transverse Electromagnetic Cell (TEM Cell) was used to expose single neurons of mollusk to the electromagnetic field.

Finite-Difference Time-Domain (FDTD) method was used for modeling the TEM Cell and the electromagnetic field interactions with living nerve ganglion and neurons. Neuron electrophysiology was investigated using standard microelectrode technique.

The specific absorption rate (SAR) deposited into the single neuron was calculated to be 0.63 W/kg with a temperature increment of 0.1°C. After acute exposure, average firing threshold of the action potentials was not changed. However, the average latent period was significantly decreased. This indicates that together with latent period the threshold and the time of habituation might be altered during exposure. However, these alterations are transient and only latent period remains on the changed level.

Waveform of the action potential (AP) was thought to be constant during long period. This point of view suggests that waveform of AP does not contain any information. However, continues evidences show opposite – the waveform of the AP is not constant and it contains some information. We have shown that AP parameters are broadened if neuron is stimulated with recurrent injection of intracellular short current impulses. This broadening follows to repetitive spiking induced by repetitive current injection. On the other hand such kind of stimulation causes neuron habituation to the stimuli, i.e. neuron declines all stimuli. The aim of present work was to give answer on the question: Do AP parameters contain some information about the process of habituation? Answer is positive. We have shown that AP parameters contain information about the habituation. Amount of this information depends on number deposited stimulus. Mentioned information was determined experimentally by the means of measurements. Experiments were carried out on the mollusk single neuron. Standard microelectrode technique was used in experiments.

During exposure to the cell phone electromagnetic field (EMF), some neurons in the brain at areas of peak specific absorption rate (SAR) absorb more electromagnetic energy than is permitted by existing guidelines. The goal of the present work was to investigate the influence of cell phone-like EMF signal on excitability and memory processes in single neurons. A Transverse Electromagnetic Cell (TEM Cell) was used to expose single neurons of mollusk to the EMF. Finite-Difference Time-Domain (FDTD) method was used for modeling the TEM Cell and the EMF interactions with living nerve ganglion and neurons. Neuron electrophysiology was investigated using standard microelectrode technique. SAR deposited into the single neuron was calculated to be 8.2 W/kg with a temperature increment of 1.21°C. After acute exposure, the threshold of firing of action potentials (AP) was significantly decreased (p ≈ 0.001). Time of habituation to stimulation with the intracellular current injection was increased (p ≈ 0.003). These results indicate that acute exposure to EMF at high SARs impairs the ability of neurons to store information.

One of the approaches to the shape analysis of the extracted segment on 2-D segmented digital image is based on its description by the points of the closed contour surrounding the segment. In simple case, the shape contour can be described by a finite set of its boundary points, for example, a sequence of the coordinates of the contour pixels. At the same time, the larger the number of points the more accurate is the contour description. But this requires a high computational cost for further process of the shape analysis. Therefore, it is very important to obtain a more accurate restoration of the original digital closed contour for the current number of pixels on the contour than using the Whittaker-Kotelnikov-Shannon interpolation formula. In this paper we use the generalized interpolation formula (Piranashvili formula) for solution of the task.

We have experimentally demonstrated that the emission of visible light from the polymer matrix doped with luminescent dye and gold nanoparticles (GNPs) can be enhanced with the use of surface plasmon coupling. GNPs can enhance the luminescence intensity of nearby luminescent dye because of the interactions between the dipole moments of the dye and the surface plasmon field of the GNPs. The electric charge on the GNPs and the distance between GNPs and luminescent dye molecules have a significant effect on the luminescence intensity, and this enhancement depends strongly upon the excitation wavelength of the pumping laser source. In particular, by matching the plasmon frequency of GNPs to the frequency of the laser light source we have observed a strong luminescence enhancement of the nanocomposite consisting of GNPs coupled with luminescent dye Nile blue 690 perchlorate. This ability of controlling luminescence can be beneficially used in developing contrast agents for highly sensitive and specific optical sensing and imaging. This opens new possibilities for plasmonic applications in the solar energy field.

Patients with a diagnosis of prostate cancer are suggested radical prostatectomy in well known cases. After this surgical operation prostatectomy specimens usually are examined histo morphologically. The aim of this examination is detection of the cancer with high accuracy in the prostatectomy specimens and determination its aggressiveness according the Gleason score. This examination would have a significant impact on the prediction of outcomes for patients after surgical operation. The entire gland and seminal vesicles are embedded, sectioned, and examined microscopically. This often means 100-120 microscopic sections including several whole-organ sections from the central part of the gland are examined. It is evident that investigation of a histomorphological samples and detection cancerous malignancy is extremely time and labor consumptive task. In this paper we show, that near infrared radiation could be successfully used as a tool for cancerous outgrowths detection in prostatectomy specimens. Thereby, positive correlation between IR findings and macroscopic and microscopic findings could lead to higher accuracy and efficiency of histo morpoholgical investigations

Background: Imaging plays a crucial role in the identification, localization and grading of prostate carcinoma. However current imaging methods for the prostate cancer diagnosis are complicated and partially invasive. The drawback of existent imaging method is that they cannot detect prostate carcinoma at early stage of development. Therefore, a key challenge for prostate cancer detection is to use a simple and noninvasive method which will able to detect the cancer with very small dimensions. Correspondingly, the aim of present work was to demonstrate the possibility of using a near infrared light for the prostate cancer detection in vitro.

Methods: Experiments were carried out on prostates obtained after radical prostatectomy. Infrared light emitted diodes were used as illumination sources. Infrared light passing through the prostate was caught by charge-coupled device connected to computer and prostate infrared transillumination images were obtained.

Results: Intensity of near infrared light passing through the noncancerous prostate tissue is nearly homogeneous. Intensity of near infrared light passing through the cancerous outgrowth is lower than the intensity passing through the non-cancerous tissue of the same prostate, thereby cancerous formations are differentiated as the dark areas on the relatively white background. Specially developed software analyzes and processes distribution of intensities of the grayscale images, measures the ratio of their strength, and determines the rate of prostate malignancy.

Conclusions: Obtained results may hold some promise to make an important contribution to the diagnosis of prostate cancer in early stage of its development.

In general, histomorphologic examination of a prostate tissue is necessary after the prostatectomy.This study was carried out to investigate a possibility of the usage of polarized light for enhancement of histo-pathological diagnosis of prostate cancer. Experiments were carried out in isolated prostates. For the obtaining of prostate infrared images a light source in the spectral range of 840-900 nm was used. Infrared light polarization measurement was perform edusing polarizers working in 700-2000 nm. Infrared polarized light incident on a CCD camera matrix was converted into electrical signals and sent to the PC for the creating visible image. Specially elaborated software converts the electrical signals, received from the CCD camera, from near infrared (NIR) into visible image, that allows us to discriminateinfrared images of healthy tissue from the malignant ones. It is shown that the intensity of near infrared (NIR) light passing through the cancerous outgrowth is lower than the intensity of NIR light passing through the non-cancerous tissue and the cancerous formations are differentiated as the dark areas in the relatively white background.

It’s known that prostate-specific membrane antigen (PSMA) is one of the most well established and highly specific prostate epithelial cell membrane antigens. PSMA is a type II transmembrane zinc metallopeptidase, belonging to the M28 peptidase family. It possesses hydrolyzing enzyme activities and is also known as FOLH1 (foliate hydrolase 1). The combination of a nanoparticle platform with targeting ligands for tumor cell-surface biomarkers is a promising architecture for achieving selective drug delivery and uptake into target cells. Gold nanoparticles (GNPs) are prone to be attached to many biological probes such as antibodies, enzymes, lectins, glycans, nucleic acids, and receptors. In this study as the prostate cancer (CaP) biomarker, we propose GNPs functionalized with PSMA and fluorescent dyes. We have investigated a possibility to obtain an increased 382fluorescence signal, gained from GNPs conjugated with fluorescent dye and PSMA. The electric charge on the GNPs, the distance between GNPs and luminescent dye molecules has a significant effect on the luminescence intensity, and this enhancement highly depends upon the excitation wavelength of pumping laser source. Charged antigen, such as PSMA, can absorb on GNPs via electrostatic interaction. As the in vitro platform, we have used a biotissue mimicking phantoms based on gelatin matrix. Gelatin-based materials are attractive due to their stable mechanical properties and ease of fabrication. Proposed method that is specific and reliable for detecting cancers at early stages and is easily accessible so that it can function as the first-line guidance is of utter importance. Further, the unique physical properties of developed nanoscale materials can be utilized to produce novel and effective sensors for cancer diagnosis, agents for tumor imaging, and therapeutics for treatment of cancer.

According to the World Health Organization (WHO) prostate cancer is the second cause of cancer death in men worldwide [1,2]. Some advanced prostate cancers have well known symptoms. However non-cancerous diseases of the prostate, such as benign prostatic hyperplasia (BPH) cause same symptoms. On the other hand, at very early stages, prostate cancer has no symptoms, the tumor dimension is quite small, and it is extremely difficult to detect it. If prostate cancer is detected at an early stage, it can be successfully cured by different methods. At the later stages, treatment or surgery has very low efficiency. Prostate cancer can often be found by measuring the amount of PSA in the blood. Most healthy men have levels under 4 nano-grams per milliliter (ng/mL) of blood. When prostate cancer develops, the PSA level usually goes above 4. However, for determination of the existence of cancer, some additional methods are used: for example: PSA velocity [3,4] and/or PSA density. Besides, measurement of the ratio of free to total PSA is additional tool in prostate cancer diagnosis [5]. However, the major drawback of PSA determination is its relative lack of specificity. The PSA level can also be increased by benign prostate hyperplasia (BPH) - a non-cancerous enlargement of the prostate, prostatitis, etc.

Near-infrared radiation is a promising approach in biomedical research in prostate cancer. Previously, this approach was used only in experiments where animal research was performed. The purpose of our experiments was to explore the possibility of using an infrared method in human prostate cancer research.

Prostate cancer is the second cause of cancer death in men worldwide. The existing methods of prostate cancer imaging are:Magnetic resonance imaging (MRI) and positron emission tomography (PET). However, main drawback of these methods isthat they are not able to detect small volumes of cancerous outgrowths. Besides, these methods are highly complicated and partiallyinvasive. This circumstance resulted in searching of amore simple, non-invasive method for the detection of prostate cancer at earlystage of its development when tumor dimensions are small. In the present work we show that near-infrared irradiation (NIR) canbe used for visualization and diagnosis of cancer outgrowth in the prostatein vitro. Experiments were carried out on the prostatesderived from radical prostatectomy. After operation a prostate was examined with the use of infrared rays and transilluminationimages were obtained. For this purpose prostate was illuminated with near infrared radiation (NIR) by the means of light emittingdiodes (850-920 nm). NIR passing through the prostate was captured by charge-coupled device (CCD camera) which in turn wasconnected to PC. Intensity of near infrared light passing through the noncancerous prostate tissue is nearly homogeneous. Intensityof near infrared light passing through the cancerous outgrowth is lower than the intensity passing through the non-cancerous tissueof the same prostate; thereby, cancerous formations are differentiated as the dark areas in the relatively white background. Speciallydeveloped software analyzes and processes a distribution of intensities of the grayscale images, measures the ratios of their strength,and determines the rate of prostate malignancy

Background & Aim: Despite the tremendous advances in the diagnosis, a prostate cancer remains as a second cause of cancer death in men worldwide. The drawback of the existent imaging method is that they cannot detect prostate carcinoma at the early stage of development. Besides, the methods are partially invasive. This circumstance resulted in searching of simple, noninvasive method for the detection of prostate cancer. In our earlier investigations, we have shown that near infrared radiation (NIR) penetrates biological tissues and particularly prostate tissue. In the present work we show that NIR can be used for the visualization of cancer outgrowth in the prostate in vitro. Methods: Experiments were carried out on the prostates derived from the radical prostatectomy. Infrared light emitting diodes (850-920 nm) were utilized for transillumination of prostates. Polarized NIR was captured by a charge coupled device (CCD) camera after passing the prostate. Prostate infrared images were visualized by a computer, coupled with CCD camera. Results: Experiments show that the optical density of cancerous and healthy prostate tissues differs from each other. Thereby, NIR penetrates healthy tissue readily than malignant one. Consequently, cancerous outgrowths are seemed as the dark spots on the bright background in a NIR transillumination images. Polarized IR light enhances transillumination images quality. Prostates were investigated with standard histo-morphological methods after NIR investigation. Results of infrared and histomorphological investigations, concerning the cancer location were compared. The comparisons show the coincidence of both findings in all cases. Developed software measures the ratios of brightness intensities of malignant and healthy tissues of prostate in the NIR transillumination images. Based on statistically reliable number of experimental data, software calculates so called confidence intervals for the data. This gives opportunity to determine malignancy of any new unknown prostate with 95% probability. Conclusions: Method of prostate cancer outgrowth NIR detection might be used in future for prostate cancer visualization and diagnosis in vivo.

Despite advances in the diagnosis, a prostate cancer remains as a second cause of cancer death in men worldwide. The drawback of the existent imaging method is that they cannot detect prostate cancer at the early stage of development. Besides, the methods are partially invasive. This circumstance resulted in searching of simple, non-invasive method for the detection of prostate cancer. In our earlier investigations, we have shown that near infrared radiation (NIR) can be used for the visualization of cancer outgrowth in the prostate in vitro. On the other hand, recent investigations show that circular polarization light can persist better its polarization property during propagating through turbid media compared with the linear polarization light. Using circularly polarized light improves the quality of image recovery in dense turbid media. It is obvious, that prostate tissue represents turbid media. In present work we show that utilization of circular polarized infrared light enhances cancerous prostate IR images.