Morphological changes in the white rats’ thyroid gland 14 days after simulated thermal trauma of the skin on the background of the administration of 0.9 % NaCl solution

According to the World Health Organization (WHO), there are about 11 million burns in the world each year, of which 180,000 are fatal. One of the systemic consequences of burn injuries is the so-called burn-associated hypermetabolism, the clinical picture of which includes immunological dysfunction, loss of bone mineral density, endocrine disorders, including thyroid dysfunction. The aim of the study was to establish histological and ultrastructural changes of the thyroid gland of experimental animals 14 days after the simulated thermal trauma of the skin on the background of using first 7 days 0.9 % NaCl solution. At the optical and ultrastructural levels of the study 14 days after thermal skin burn on the background of 0.9 % NaCl solution in the thyroid gland of experimental animals found: follicles – mostly large, overstretched (epithelium flat, with desquamation); cytoplasm of thyrocytes is poor in organelles, part of mitochondria with damaged cristae and enlightened matrix, available electron-dense lysosomes, apical surface smoothed; there is swelling of the capsule and trabeculae, leukocyte infiltration; components of the arterial and venous bed are dilated, there is a deformation of the lumen of blood vessels; hemocapillaries are dilated with numerous erythrocytes and perivascular edema. The detected changes cause a violation of the secretory cycle of thyrocytes, transendothelial metabolism and lead to an imbalance in the production and excretion of thyroid hormones.

The Effectiveness of Local Application of Melatonin in the Original Dermal Film in Experimental Thermal Trauma

Background: The development and pathogenetic substantiation of the new agents used for local therapy of thermal trauma (TT) is an urgent problem in medicine. Melatonin (MT) is an endogenous factor of homeostasis regulation with pleiotropic potential. The aim of our study was to assess the morphology, expression of matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF), indicators of repair, oxidative destruction of lipids in the skin lesion focus in the dynamics of experimental TT under the conditions of using the original dermal film (DF) with MT. Methods and Results: The experiment was performed on 104 male Wistar rats weighing 200-240 g. For modeling TT II degree according to ICD-10 a relative area of 3.5% of the body surface, an interscapular region isolated from the surrounding tissues, was immersed in distilled water at 98-99 °C for 12 sec. DF based on sodium carboxymethylcellulose with an area of 12 cm2 with MT at a concentration of 5 mg/g was applied daily for five days. The wound area and epithelialization rate were calculated. The content of MMP-9 and VEGF in the burn wound was assessed by an immunohistochemical method. In the homogenate of the burn wound, the content of LPO products was assessed. Morphological and biochemical studies were performed on Days 5, 10 and 20 after TT induction. With experimental TT from Day 5 to Day 20, the absolute area of the burn wound decreases by 35%, the rate of epithelialization increases, the number of neutrophils in the focus of thermal damage decreases, while the representation of lymphocytes, histiocytes, and fibroblasts increases; the expression of MMP-9 and VEGF increases; predominantly secondary and final LPO products in the heptane phase accumulate, the final products of LPO in the isopropanol phase of the lipid extract. The use of MT in the composition of DF daily for 5 days with experimental TT leads to a decrease in the area of the wound defect (by 46% of the original area on Day 20), an increase in the rate of its epithelialization, an increase in the content of lymphocytes and fibroblasts in the burn wound on Days 5, 10 and 20 of TT, a decrease in the representation of neutrophils and macrophages on Days 5 and 10, as well as an increase in VEGF expression on Days 5 and 10, MMP-9 - on Day 5 and a decrease in MMP-9 expression on Days 10 and 20 of TT. In addition, the use of MT in the composition of DF leads to a decrease in the content of predominantly secondary and end products of LPO in the heptane and isopropanol phases of the burn wound on Days 10 and 20 of TT. Correlation analysis revealed that a decrease in the burn surface area under a local application of MT occurs with an increase in the content of VEGF in the wound area and a decrease in the content of MMP-9 and secondary and final LPO products in the heptane phase and the isopropanol phase. On Day 20, there were direct moderate correlations between the absolute burn surface area, on one hand, and secondary and final LPO products, on the other, in the heptane phase (R=0.51, R=0,68; P<0.05) and the isopropanol phase (R=0.44, R=0.46; P<0.05), respectively. Conclusion: The results obtained expand the existing understanding of the role of changes in the expression of MMP-9 and VEGF in the pathogenesis of TT. We believe that the repair-stimulating effect of MT in the DF, which we established during TT at the preclinical stage, is associated with the LPO-limiting effect of MT and a change in the expression of MMP-9 and VEGF in the burn wound and is a prerequisite for further study of the mechanism of action and the effectiveness of MT application in clinical conditions in TT.

BLOOD CYTOKINE PROFILE AND LESION SITE REPAIR IN DYNAMICS OF EXPERIMENTAL THERMAL TRAUMA AFTER LOCAL AND SYSTEMIC MELATONIN ADMINISTRATION

Burn injuries are one of the key medical and social problems. Despite the significant achievements in combustiology, the slow healing and the appearance of infection are the key problems in burn patients, which lead to a longer hospitalization period, to reduction of life quality and to emotional disorders. Up to 70% of all complications after thermal trauma (TT) are connected with infection – first of all, pneumonia, infections of urinal tract. The forming of infectious complications, including sepsis, after TT is associated with excessive immunosuppressive reactions, as compensation for a long, stable proinflammatory response, in particular, owing to hyperproduction and effects of IL-10, IL-4, TGF-β. Aim: to study the influence of systemic and local usage of MT with original dermal film (DF) on reparation and serum cytokine concentration indicators in dynamics of experimental TT. The study was conducted using 84 rats – males of Wistar line, which were divided randomly into 4 groups: 1st group (n = 12) – intact monitoring, 2nd group (n = 30) – animals with TT, 3rd group (n = 21) – animals with TT and DF with MT use on the region of burn, 4th group (n = 21) – animals with TT and intraperitoneal injection of MT. To model TT of IIIA degree and relative area 3,5%, isolated skin area of interscapular area was immersed in distilled water at a temperature of 98-99 °С at 12 s. The DF with MT (at a concentration of 0.005 g/g) on 12 sm2 – area in 3rd group was used daily for 5 days. The MT was injected intraperitoneally daily at the dose of 10 mg/kg for 5 days. The wound area was calculated, the interleukin-4 (IL-4), tumor necrosis factor alpha (TNFα), interferon-gamma (IFNγ) were determined in serum on 5th,10th and 20th day from the moment of TT induction in each group. During experimental TT in dynamic monitoring from 5th to 20th day the absolute and relative areas of wound defect are reduced, because of that the epithelization speed and its part of area reduction are progressively increasing, on 5th,10th and 20th day the concentration of TNFα and IL-4 in serum is increasing with maximum values on 10th day of monitoring. Local usage of MT in DF during TT accelerates the healing of burn wound and lowers the TNFα and IL-4 concentration in serum on 5th, 10th and 20th day. Intraperitoneal use of MT during TT accelerates the healing of burn wound and lowers the TNFα and IL-4 concentration in serum on 5th and 20th day. The reparation accelerating effect of MT during TT is more expressed in locale usage in DF rather than using intraperitoneal injection.

THERAPEUTIC EFFECT OF SINGLET OXYGEN ADMINISTRATION ON CRYSTALLIZATION OF RATS’ BLOOD SERUM AT THERMAL TRAUMA

Biological and therapeutic effects of singlet oxygen have not been investigated yet. The aim of this paper is to estimate the influence of a short course (10 days) of singlet oxygen inhalations on crystallogenic properties of rats’ blood serum. The experiment was performed on 30 male Wistar rats, randomly divided into three equal groups. The first group was intact. The animals of the 2nd (control) and 3rd (test) groups under combined anesthesia were subjected to thermal trauma. Starting from the day following the injury, the rats of the test group inhaled daily the air flow from a singlet oxygen generator during 10 days. Blood samples were obtained from the rats of all groups. Dried samples were evaluated visually for crystallizability, structure index, facia destruction degree, and marginal zone clarity, using respective scales. It is stated that singlet oxygen inhalations facilitate the elimination of negative transformations in blood crystallization induced by thermal trauma. It indicates the positive rehabilitation potential.

Local effect of melatonin in an original dermal film limiting lipid peroxidation and accelerating healing in experimental thermal trauma

Разработка и патогенетическое обоснование новых подходов к локальной терапии термической травмы (ТТ) является актуальной и востребованной проблемой. В частности, представляет интерес разработка дермальных пленок (ДП), содержащих эндогенные регуляторы гомеостаза мультитропного действия. Цель исследования - оценка эффекта мелатонина (МТ) в составе оригинальной ДП на процессы репарации и содержание продуктов перекисного окисления липидов (ПОЛ) в коже очага повреждения при локальной термической травме. Методика. Эксперимент выполнен на 126 крысах-самцах Wistar. ТТ ІІІА степени площадью 3,5% моделировали погружением участка межлопаточной области кожи в очищенную воду с температурой 98-99 ºС на 12 с. МТ в составе ДП (0,005 г/г) на основе натрия карбоксиметилцеллюлозы наносили ежедневно после ТТ в течение 5 сут. На 5-е и 10-е сут после ТТ оценивали макроскопическую картину, площадь и глубину ожоговой раны, скорость ее эпителизации. Содержание продуктов ПОЛ в гомогенате кожи ожоговой раны определяли экстрационно-спектрофотометрическим методом в гептановой и изопропанольной фазах липидного экстракта. Результаты. Установлено, что накопление вторичных и конечных продуктов ПОЛ в гептановой и изопропанольной фазах липидного экстракта на 5-е и 10-е сут ассоциировано с площадью ожога. Применение оригинальной ДП с мелатонином приводит к снижению абсолютной и относительной площади ожога, увеличению скорости эпителизации ожоговой поверхности. На 5-е сут обнаружено снижение содержания вторичных и конечных продуктов ПОЛ в изопропанольной фазе, на 10-е сутки - снижение вторичных продуктов ПОЛ в гептановой фазе, конечных продуктов ПОЛ в изопропанольной фазе липидного экстракта. Заключение. Полученные результаты демонстрируют ускоряющий репарацию кожи в очаге ТТ эффект МТ в составе дермальной пленки за счет его ПОЛ-ограничивающего действия, расширяют представления о мультитропных эффектах МТ в организме и являются предпосылкой для применения ДП с МТ в клинической практике. Background. Development and pathogenetic justification of new approaches for local therapy of thermal trauma (TT) is a relevant and in-demand issue. Of special interest are dermal films (DF) containing endogenous pleiotropic regulators of homeostasis. Melatonin (MT) is one of such regulators that is suggested to be protective in TT. The aim of this study was to evaluate the effect of MT in the original DF on indexes of repair and concentration of lipid peroxidation (LPO) products in the injured skin after experimental TT. Methods. Experiments were performed on 126 Wistar male rats. Grade IIIA TT with an area of 3.5% was modeled by immersing a section of interscapular skin in purified water at a temperature of 98-99oC for 12 s. MT formulated into DF (0.005 g/g) based on sodium carboxymethylcellulose was applied after TT daily for 5 days. The macroscopic picture, area and depth of the burn wound, and the wound epithelization rate were evaluated on days 5 and 10 after TT. Concentration of LPO products in the injured skin homogenate was measured by extraction spectrophotometry in heptane and isopropanol phases of the lipid extract. Results. The accumulation of secondary and final LPO products in the heptane and isopropanol phases of the lipid extract on days 5 and 10 was associated with the burn area. The use of the original DF with MT resulted in a decrease in the absolute and relative areas of the burn and an increase in the rate of burn surface epithelialization. On day 5, a decrease in the content of secondary and final LPO products in the isopropanol phase was observed, and on day 10 decreases in secondary peroxidation products in the heptane phase and end LPO products in the isopropanol phase were detected. Conclusion. The results of this study demonstrated that MT formulated into DF accelerates skin repair in the TT focus due to its LPO-limiting effect, expands the understanding of MT pleiotropic effect, and represents a prerequisite for the clinical use of DF with MT.

Modern dressings in treatment of patients with deep burns

Treatment of burns is a complex, multi-stage and financially costly process. Methods of treatment of patients with thermal trauma are currently continuing to improve: a multidisciplinary approach to treatment is being formed; burn centers have been established, where doctors of various specialties (surgeons, traumatologists, anesthesiologists, rehabilitologists, therapists, ophthalmologists and many others) participate in the treatment of patients. However, to date, the question of wound treatment in patients with deep burns at the stages of preparation for plastic closure and after autodermoplasty with a split perforated 1:4 graft remains open. It is known that extensive and deep burns are accompanied by the development of wound infection, which is one of the important factors that disrupt the epithelization of wounds. This results in lysis of the grafts and may require repeated surgery or long-term conservative treatment at the site of the operation.

Electron microscopic changes in the skin of rats 1, 3, 7, 14, 21 and 30 days after thermal trauma on the background of the introduction for the first 7 days of 0.9% NaCl solution

A burn wound occurs as a result of exposure to high-temperature skin or chemicals and is a serious injury with systemic effects. The problem of treatment of thermal trauma is urgent for modern medicine. Despite the fact that the overall mortality rate has dropped significantly in recent years, research about the development of new treatments and technologies for patients with skin burns is extremely important. The aim of the study is to research the features of electron microscopic changes in the skin of rats during the month after burns of II-III degree against the background of the introduction of the first 7 days of 0.9% NaCl solution. Studies were performed on 180 laboratory white rats-males weighing 155-160 g. In the course of the experiment, the animals were divided into 2 groups: 1 – rats without thermal injury, which were infused with 0.9% NaCl solution at a dose of 10 ml/kg; group 2 – rats which infused 0.9% NaCl solution at a dose of 10 ml/kg for 7 days after skin burns. Burning skin damage was caused by applying to the lateral surfaces of the trunk of rats for 10 seconds four copper plates, heated in water at a constant temperature of 100 C. The total area of skin lesion in rats was 21-23%. Shaving of the lateral surfaces of rats’ trunk, catheterization of veins, staging of skin burns, and decapitation of animals (after 1, 3, 7, 14, 21 and 30 days) were performed under intravenous propofol anesthesia (calculated at 60 mg/kg body weight). Preparations for electron microscopic examination were prepared according to the standard procedure. The data obtained were studied using a PEM-125K electron microscope. Electron microscopic studies of the skin of animals after thermal trauma under the conditions of application of 0.9% NaCl solution have found that in the early stages of the experiment – the stage of shock and early toxemia (1, 3, 7 days) compensatory and adaptive changes of its structural components are combined with signs of destructive disorders. In the epitheliocytes of the epidermis of the affected area of the skin is the destruction of nuclei and cytoplasm. Vascular disorders in the dermis are combined with changes in fibroblasts, an intercellular substance of fibrous connective tissue. In the late stages of the experiment – the stages of late toxemia and septicotoxemia (14, 21 and 30 days), there is a further development and deepening of destructive-dystrophic changes of all structural components of the affected skin, they become irreversible. The processes of granulation tissue formation, its transformation into connective tissue, as well as marginal epithelialization are slow. This morphological condition of the burn wound indicates the need for the use of corrective drugs to reduce destructive changes and the activation of regenerative processes in the area of skin lesions.