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The use of the terapeutic laser in medicine
VESELÝ, Jan
Modern diagnostics and therapy is nowadays very strongly influenced by technological developments. New discoveries in physics, electronics and other fields lead to search for applications in the medical field. Laser is no exception. It is one of the most important technological discoveries of the late 20th century. A lot of targeted researches and multiple observations demonstrated beneficial effects of the laser radiation on living tissue. Laser was also confirmed to be used in medicine. Recently, laser therapy has been more and more popular. Lasers have found their place and application in almost all areas of medicine, both in treatment and also in research; it has been constantly developing dynamically. Laser Therapy (LLLT) is a branch of phototherapy, which uses light (laser or non-coherent monochromatic beam) for treatment of various diseases. Laser means light amplification by stimulated emission of radiation. This method of treatment is special as it does not lead to serious side effects and treatment does not take so much time to show effectiveness. Laser therapy is very far from practical use of surgical lasers. Laser Therapy (LLLT) is something different containing a lot of scientific utilization characteristics of the laser beam; it uses different colours of the beam to achieve the desired effect for treatment of a particular disease, the correct dosage etc. Surgery uses surgical properties of lasers. These include e.g. surgical knife cutting or tissue welding. Laser therapy possibilities, however, go much further. In this therapy laser is not a mere tool, but a medicine in itself. The power of the therapeutic laser power can be thousands of times smaller and weaker than the power of the surgical one. Many patients still assume that laser therapy consists in the use of surgical lasers, which is, however, not correct. Laser therapy uses non-surgical lasers, which neither cut nor burn. Application of therapeutic laser produces the desired effect in the patient's body by means of the way of cell changes in all cells that are exposed to the beam. It causes increased protein synthesis, immunocorrection, increased ATP production, increased enzymatic activity and circulation, and collagen synthesis. Lasers also regulate lipid metabolism, normalize blood pressure, reduce swelling and inflammation, and reduce pain. Furthermore, leasers have an anti-inflammatory effect, they cause increased cell division and increase immunity against diseases. Lasers have stimulatory, and generally rejuvenilizing and generally healing effects, but when adjusting their dosage they are inhibitory. Thus, using the therapeutic laser brings effective treatment, even if allopathic approach calls many of them incurable.
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Study of senzitizers phototoxicity on molecular level and possibilities their use for photodynamic tumors therapy
ZEMAN, Jan
Photodynamic therapy is a modern and promising method of treating some types of tumors. It can supplement and in some cases even replace the current methods. It is based on the use of a photosensitive substance, a senzitizer, which is located in tumor cells and subsequently exposed to the light of an approporiate wave length, which brings about photodynamic reaction. Photodynamic reaction arises due to the combination of four agents: a senzitizer, molecular oxygen, light of optimum wave length, and a biological substrate (proteins, nucleic acid or other cell components). After the application of the senzitizer, whose prior uptake takes place in the pathologically altered tissues, visible light of a wave length corresponding with the absorption maximum of the photosenzitizer is applied, which brings about tumor cells destruction at active participation of the reactive oxygen forms as superoxide anion, hydrogen peroxide and hydroxyl radicals. My thesis was focused on testing photodynamic properties of ZnTPPS4 senzitizer on tumor cell lines. The production of oxygen reactive forms was tested by Synergy HT spectrofluorimeter and Olympus IX 81 fluorescence microscope with image analysis. Production of reactive oxygen forms was assessed with the use of molecular symbol CM-H2 DCFDA. LED emitters adapted for working with cell cultures were used to irradiate the cell structures. The results proved that ZnTPPS4 is photodynamically effective and the production of reactive forms of oxygen depends on senzitizer ZnTPPS4 concentration as well as on the dose of radiation.
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The study of photodynamic phenomenon on melanom cell lines
KOLÁČKOVÁ, Zdeňka
Photodynamic therapy (PDT) is a medical method combining the use of photodynamic active substance and light in presence of oxygen. It extends the treatment possibilities of tumor and non-tumor disorders. It complements surgical treatment, radiotherapy, chemotherapy and immunotherapy. An increased accumulation of photosensitive substance in pathological focus is the base of PDT. Subsequent irradiation by light of suitable wavelenght evokes photodynamic reactions leading to formation of reactive oxygen species and to biological answer leading to tumor cells damage. The final effect depends on sensitizer type, its concentration in target tissue and on used source of radiation. Aim of the thesis is to prove photodynamic properties of newly developed photodynamic active substance phtalocyanin CIAIPcS2 and possibilities of its usage to induce photodynamic phenomenon in melanom cells. Owing to absorption of light in sensitizer the formation of excited states happens, and then the excited form of sensitizer reacts directly with substrate. During this reaction free radicals of substrate form or transfer of energy from sentitizer to oxygen and formation of highly reactive singlet oxygen happen. Free radicals, especially radicals of lipid components of cell membranes, are the major cause of tumor destruction. Fruitfulness of PDT depends not only on type of sensitizer and level of oxygen in tumor cell but also on used light source. Luminiscence diodes (LEDs) were used as the source of light. Formation of ROS after PDT was detected with the help of fluorescent molecular probe CM-H2DCFDA on spectrofluorimeter Synergy HT and on fluorescent microscope Olympus IX 81 with image analysis. According to our results the production of ROS depends on concentration of sensitizer CIAIPcS2 and the radiation dose. We proved that the sensitizer CIAIPcS2 is suitable photodynamic active substance and evokes photodynamic phenomenon in tumor cells.
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