Search

Background.Osteoporosis is the fourth most common disease after cardiovascular diseases, cancer, and diabetes. All these diseases have common pathogenetic mechanisms associated with impaired cholesterol metabolism. In recent decades, the use of the key enzyme of cholesterol synthesis inhibitors — statins, which can stimulate osteogenesis, has become widespread. However, statins affect the production of the vitamin D active form by reducing the production of testosterone and thus reducing the activity of 1α-hydroxylase. The combined use of statins and α-calcidol (α-C) for the osteoporosis prevention seems promising. The aim of the study was to evaluate the effect of long-term atorvastatin (ATV) and α-C administration on morphometric growth parameters and bone vascularization in the experiment.Materials and Methods. The experiment was conducted for three months on 120 laboratory male rats, which were injected daily intragastrically with ATV and α-C. After 90 days of the experiment, the animals were decapitated under ether anesthesia. For the study, the right femur and jawbone were taken from the animals. The rat bone sections were impregnated with silver, decalcified, and the histosections were stained according to van Gieson. The distribution of the studied features was evaluated according to the Shapiro-Wilk test. The differences were considered statistically significant at p0.05.Results.It was found that ATV, both separately and together with α-C, increased the size of the newly formed bone in the endoostal and periosteal zones of the femur by 64.8; 40.4 and 15.8; 29.1%, respectively. The combined use of ATV and α-C had a positive effect on the growth of blood vessels in the femur (+23.4%). ATV increased the size of the newly formed bone from the periodontal and vestibular surfaces of the lower jaw by 18.3 and 29.5%, respectively. α-C potentiated the effect of ATV on the size of the newly formed bone tissue in the periodontal and vestibular growth zones of the mandibular bone by 10.1 and 15.0%, respectively. As for the number of vessels in the jawbone tissue, thanks to ATV, it increased by 17.2%, α-C had no effect.Conclusion. ATV increases the thickness of the newly formed bone layer in the growth areas of the femur and jawbone and increases the number of vessels in the jawbone. α-calcidol increases the number of vessels in the bone tissue of the femur and potentiates the effect of ATV on the jawbone growth zones. The combined use of ATV and α-C shows that they positively complement each other.

Purpose: to study the histological features of the Muller muscle of the upper eyelid in patients with congenital and acquired ptosis to understand the mechanism of ptosis. Material and methods. Retrospective analysis of 27 intraoperatively obtained biopsies of the Muller muscle of the upper eyelid. For the study, the biopsies were fixed in a formalin and prepared by paraffinization. After staining with hematoxylin and eosin and Van Gieson, the preparations were studied in a light microscope. Results. In congenital ptosis of the upper eyelid histologically revealed atrophy of smooth muscle tissue, which manifested itself in a decrease in the number of muscle fibers on the background of fibrous transformation. In micro specimens of patients with acquired ptosis discovered fat cells located among the bundles of smooth muscle fibers, the dispersion of the myocytes. Fat infiltration of muscle ranged from 29 to 51.6 %. Conclusion The presence of dystrophic changes in Muller muscle in congenital and acquired ptosis was proved by histological method. The revealed features explain the pathogenetic mechanisms of the formation of congenital and acquired ptosis. In the case of acquired ptosis, fat dystrophy is an independent etiological factor, and therefore requires non-standard tactics of surgical treatment in order to neutralize the risk of recurrence in the early and late postoperative periods.

Aim. This experimental work presents a comparative assessment of the effect of hyaluronic acid and crystalline calcium hydroxyapatite on derma in separate and combined application setting.Materials and methods. The study used rats (30 animals) for subdermal injection of 0.05 ml medium. Group 1 was administered calcium hydroxyapatite (Radiesse (Merz, Germany)), group 2 received hyaluronic acid (Restylane (SabQ, Sweden)) and Group 3 — both preparations combined in ratio 1:1 (Mix). Results were evaluated 4 months after the filler injection. Sections were stained with haematoxylin–eosin, van Gieson’s and Masson’s trichrome techniques. Collagen types I and III were detected with polyclonal antibodies (Abcam, England). Fibroblasts were positively identified with vimentin (LabVision), macrophages — with CD68 (LabVision) tagging. Effect of extracellular matrix remodelling was studied with α-SMA actin (Abcam, England).Results. We demonstrate that separate filling of hyaluronic acid and calcium hydroxyapatite produces different response mechanisms, while their combined administration does not lead to a marked voluming of the dermal extracellular matrix.Conclusion. Combined administration of the two fillers under study may facilitate a prolonged effect of their combined action exceeding 4 months, due to the absence of fibrosis, complications and side effects.

The aim of the article is to evaluate Bischofit gel reparative activity in a linear wound model in rats.Materials and Methods. The study was conducted on 36 male Wistar rats weighing from 193 to 218 grams. On the 8th day after modeling a linear wound defect 50±1 mm long, the reparative effect of bischofite, Actovegin and Contractubex in the gel compositions was evaluated. The evaluation was carried out using: the following methods: 1) studying the physicomechanical characteristics of the wound defect (a wound-tearing machine Metrotest REM-0.2-1); 2) morphological examination of the skin graft taken from the wound area (stained with hematoxylin-eosin and Van Gieson‘s solution); 3) determining the ratio of collagen types I and III in a polarizing microscope (the picrosirius was red); 4) cоlorimetric analysis of the hydroxyproline concentration in the wound surface tissues.Results. On the 8th day, the wound defects sampled from the bischofite treated animals, were characterized by the most pronounced strength (the average force at the rupture moment was 13.70 N), which was significantly higher (p Actovegin (0.67±0.017) > Control (0.56±0.012) > Contractubex (0.38 ±0.020).Conclusion. The carried out study showed that Bischofit has a pronounced ability to stimulate the regeneration of the skin wound defect. Hereby, the reference drug Actovegin showed less activity, and Contractubex worsened wound healing.

Aim.The study was conducted for the characteristics of the morphoimmunohistochemical status of the implant from polylactic acid (PLA) located in the dermis.Materials and methods.The study was performed on rats (30 individuals) with subdermal administration of the drug in a volume of 0,05 ml. The results were evaluated after two weeks, 1 and 2 months after the injection. The sections were stained with hematoxylin and eosin, according to Van Gieson, with the help of Mallory and Masson reaction. Collagen fibers were studied after the staining with picrosirius red under polarized light. Monoclonal antibodies of CD 68 and antibodies to vimentin were used to determine the expression of immunohistochemical markers.Results. It is shown that the rate of collagen synthesis varies in different parts of the dermis. There is a sharp increase in the volume of the fibrous component around the implant, and there is only a tendency to increase in the synthesis in the implant itself. In this case, the increase in the volume of the extracellular matrix is associated with type I and III collagen.Conclusion.The detected activation of collagen synthesis by fibroblasts can be used as a regulator of the volume of the matrix, which is very important for the modern regenerative medicine.

The search for new types of bone substitutes is one of the topical problems of biology and medicine. The paper considered the role of fibrous autograft in reparative bone regeneration in the rat's lower jaw model. Thirty Wistar rats were taken in the experiment: 15 in the experimental and 15 in the control group. Fibrous autograft was formed on the cellophane basis under the skin on the back of rats. Injury in the lower jaw with a diameter of 2 mm was formed and a fibrous graft was placed in injuries in the experimental group. Five animals from each groups were sacrificed at the first, third and fifth weeks of the experiment. The object of the further research was the samples of the lower jaws stained according to Van Gieson. Histological examination of the bone defect of the experimental group after 1 week showed absence of bone fragments and formation of fibrous callosity in the trauma zone. Further study of regenerate at the 3rd and the 5th weeks showed accelerated bone wound healing in the experimental group (compared to the control group). Thus, the autograft stimulates the process of bone tissue restoration in the area of the defect of the lower jaw model. © 2021 Acta Biomedica Scientifica. All rights reserved.

Objective: to reveal aortic structural changes in the recovery period after longterm hemorrhagic hypotension and further blood reinfusion. Material and methods. Two (control and experimental) series of eexperiments were carried out on 10 out bred albino male rats in each. The animals were anesthetized with sodium thiopental (25 mg/kg). Sixtyminute hemorrhagic hypotension (40 mm Hg) was induced by left common carotid artery catheterization, followed by blood reinfusion and wound closure. The animals were observed for 60 days, thereafter thoracic and abdominal aortic fragments were taken. The histological sections were stained with hematoxylin and eosin by the methods of Van Gieson, Verhoeff, and Veigert. Morphometric and histometric parameters, including the percentage of layers in the vascular wall and transmission capac ity coefficients, were determined. Results. The thoracic and abdominal aortic sections have been found to differ in morphometric parameters, which determined their different hemodynamic conditions in critical conditions. Hypertrophy of the media of the abdominal aorta due to thickening of the smooth muscle layers suggests that there are remodeling processes in its wall, which is accompanied by a smaller number of elastic membranes and by the expression of сollagencontaining structures after massive blood loss. For the thoracic aortic segment, such changes are manifested by a decreased medial area, a considerable advential thickening, and a drastic fall in transmission capacity coefficients. Conclusion. The found morphometric characteristics of different aortic segments should be considered as the basis for longlasting adaptation, which can supply blood to the vital organs as efficiently as possible in late recovery periods.