RESUMEN
BACKGROUND: Mesenchymal stem cells based paracrine bioactive factors that deploy their task as an essential mechanism, but their efficiency for skin regeneration still requires clarification. METHODS: The mesenchymal stem cell-based paracrine factors were administered by subcutaneous injection of 0.5 mL peptides (general protein 8 mg/mL). These were performed after radiation on different days like the first, third, sixth, eighth, and 10th. To determine the consequences, we performed photography, planimetry, and preclinical test each week after 15 days of radiation. MSC-based peptides were injected into a rat that had radiation burns, and its observation encouraged cell-free therapeutic remedies to regenerate skin. Both control and experimental groups were exposed to 110 Gy of X-rays, which resulted in the formation of localized radiation burns on the skin (S=6 cm2) 15 days later. Thirty days after radiation, the wound stabilized (surface of the wound was S=2.2±0.2 cm2) and fluctuated throughout the course of the pathological process. RESULTS: The wounded area on the skin from the 15th to the 29th day after radiation was practically the same in both groups. The wounded area gradually reduced by 6.1±0.4 cm2 (experimental group) and 5.9±0.6 cm2 (control group) 15 days after radiation up to 2.2±0.3 cm2 (in both control and experimental groups) on the 29th day after radiation. However, starting from the 36th day, there was a constant reduction in the burn area in the experimental group up to 0.2±0.1 cm2 till the 71st day after radiation. CONCLUSION: In the control group, the area of the lesion ranged from 1.4±0.6 cm2 on the 50th day to 1.9±0.8 cm2 on the 71st day. During the 57th to the 71st day, the difference between the affected area in the experimental and control groups was 1:8. The experimental group has a significantly higher level of skin regeneration and significant decrease in the level of leukocyte infiltration, thereby reducing necrosis.
RESUMEN
The original method is proposed for the study of apoptosis kinetics in cell populations by determination of apoptotic cell accumulation during the day's incubation in serum free medium. We have studied the features of this process for peripheral blood granulocytes and lymphocytes from healthy children. High sensitivity of the proposed method has been shown for the estimation of apoptosis, taking for illustration the analysis of delayed chemotherapy influence on blood cells in children, recovered from acute limphoblastic leukemia (ALL). In children with ALL, the delayed myelosuppressive effect of antileukemic therapy has been proved to be not only in relation to the increase of blood cell ability to spontaneous apoptosis, but also to induce the certain impairments in the kinetics of this process.
RESUMEN
The capability of peripheral blood leukocytes and bone marrow cells to spontaneous apoptosis was studied in 36 children with ALL remission at various periods after polychemotherapy withdrawal. The enhancement of apoptotic activity has been revealed to be the universal mechanism of delayed effect of antileukemic chemotherapy for all the compartments of hemopoiesis, including granulocyte/macrophage precursors. The expression of this phenomenon is decreasing with the time period elapsed after treatment withdrawal. However, approximation analysis shows that the recovery of normal values of blood cell apoptosis occurs not earlier than 8 years after therapy withdrawal. Therein, in should be noted that the numbers of leukocytes don't differ from normal values at all the periods of observation. The growth of proliferative potential for precursor cells and the increased proportion of proliferating granulocyte pool of bone marrow are shown to be the probable mechanisms contributing to compensation of enhanced ability of blood cells to apoptosis.