We present the results on the interaction of an all-fiber Holmium-doped laser CW radiation at a wavelength of 2100 nm with soft tissues and compare it with the other results obtained by the most used solid-state laser systems. Ex-vivo single spot experiments were carried out on the porcine longissimus muscles by varying the laser impact parameters in a wide range (average output power 0.3, 0.5 and 1.1 W; exposure time 5, 30 and 60 s). Evaluation of the laser radiation exposure was carried out by the size of coagulation and ablation zones on the morphological study. Exposure to a power of 0.3 W (1.5–18 J of applied energy) caused only reversible changes in the tissues. The highest applied energy of 66 J for 1.1 W and a 60-s exposure resulted in a maximum ablation depth of approximately 1.2 mm, with an ablation efficiency of 35%. We have shown that it is not necessary to use high powers of CW radiation, such as 5–10 W in the solid-state systems to provide the destructive effects. Similar results can be achieved at lower powers using the simple all-fiber Holmium laser based on the standard single-mode fiber, which could provide higher power densities and be more convenient to manufacture and use. The obtained results may be valuable as an additional experimental point in the field of existing results, which in the future will allow one to create a simple optimal laser system for medical purposes.

We present the results of ex vivo exposure by an ultrafast all-fiber Holmium laser system to porcine longissimus muscle tissues. A simple Ho-doped laser system generated ultrashort pulsed radiation with less than 1 ps pulse width and a repetition rate of 20 MHz at a central wavelength of 2.06 μm. Single-spot ex vivo experiments were performed at an average power of 0.3 W and different exposure times of 5, 30 and 60 s, varying the total applied energy in the range of 1.5–18 J. Evaluation of laser radiation exposure was performed according to the depth and diameter of coagulation zones, ablation craters and thermal damage zones during the morphological study. Exposure by ultrashort pulsed radiation with an average power of 0.3 W showed destructive changes in the muscle tissue after 5 s and nucleation of an ablative crater. The maximum ablation efficiency was about 28% at the ablation depth and diameter of 180 μm and 500 μm, respectively. The continuous-wave radiation impact at the same parameters resulted only in heating of the near-muscular tissue, without ablation and coagulation traces. Exposure to tissue with an average power at 0.3 W of ultrashort pulsed radiation led, within 30 and 60 s, to similar results as caused by 0.5 W of continuous-wave radiation, although with less carbonization formation.

In alimentary adiposity, some microelements take active part in the metabolism change that proves to be true by an essential deviation from the norm of their concentration in liver and lung tissues during the physiological hunger and soon after fat consumption. The concentrations (in µg/g) of the following chemical elements P, S, Cl, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, and Sr were determined by synchrotron radiation excited X-ray fluorescence (SRXRF) analysis. The measurements were carried out at the experimental station of X-ray fluorescence elemental analysis (Budker Institute of Nuclear Physics SB RAS, storage ring VEPP-3). In alimentary adiposity, deficiency of separate microelements does not concern all organisms, but only some organs. At the condition of physiological hunger in the liver and lungs of rats with alimentary adiposity, the concentrations of As and Br are decreased; besides, in lungs the concentrations of Zn, Se, and Rb are also lowered. Copyright

Histochemical study of rat pancreas was carried out on days 14 and 30 of acute pancreatitis. The area of the stroma increased after damage and the area of lymph microcirculatory component increased in comparison with the blood circulation component.

The authors present a review of publications in the scientific and medical literature on modern concepts of mechanisms of low-level laser biostimulating effects at the human body, at microvasculature chains and lymphoid organs. The main aspect of microcirculation photoactivation is the process of microcirculation reconstruction which leads to prolonged improvement in tissue trophism. There are three processes in the basement of biostimulating effect of low-level laser light in the red and near infrared spectral regions at microcirculation: hemomicrocirculation enhancement, activation of capillary neovascularization, lymphocorrection effects at the structure and functional activity of lymphoid organs.

Morphological transformations occurring in the thymus and lymph nodes are studied in Wistar rats after irradiation of the thymus projection area and transcutaneous irradiation of peripheral blood with a low-energy helium-neon laser during a 7-day period. Irradiation of the thymus projection area stimulates lymphopoiesis in T-dependent zones of lymph nodes, while irradiation of peripheral blood increases lymph flow through lymph node parenchyma and activates B-dependent zones.

We studied structural changes in the prostate gland, thymus, and lymph nodes in CBA mice after transplantation of Ehrlich ascites tumor cells into the prostate gland. On experimental day 5, the number of blood and lymph vessels decreased in the gland; the percentage of connective tissue elements and glandular tissue and the number of immunoblasts in the thymus increased. On day 18, the number of blood vessels in the tumor decreased; the width of the cortex and glandular tissue increased in the thymus, while the number of immunoblasts was reduced. On day 28, tumor infiltration and increased number of lymphatic vessels in its stroma were observed; parenchyma was reduced, and the area of the connective tissue increased in the thymus. These structural changes indicated the development of accidental involution of the thymus during carcinogenesis of the prostate.

Aim: To study and evaluate degree of morphological changes in intima of great saphenous vein (GSV) in patients of different age groups in health and in venous disease. Materials and methods: We investigated autopsy material of GSV in 60 deceased patients and postoperative material of GSV in 80 patients with venous disease. Four age groups were formed: young age, middle age, older and elderly age. Totally there were 280 GSV fragments. Histological, morphometric, electron microscopic and biochemical studies were performed. Results: Our results are mainly consistent with the reference data. However, we carried out a comparative study of intima structure in norm and with venous disease in patients of different age. At the same time due to agerelated decline in varicose veins morphological changes are progressing. There are areas of endothelium atrophy and signs of fibrotic replacement in young and middle age patients with venous disease, whereas in older and elderly patients desquamation of endothelium and sclerosis were observed. Conclusion: Progressive degeneration in older and elderly patients with varicose veins promotes morphological changes of GSV and progression of the disease on histological and ultrastructural level that worsens endothelial dysfunction.