The aim: To study the effect of a high-fat diet (HFD) on the structural changes in the aortic intima in intact and HSV-1-infected mice using Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Materials and methods: In experiments Balb/c mice were infected with the HVS-1 and fed high-fat diet and 12 weeks later aortic ultrastructure was examined by SEM and TEM methods. The animals were subdivided into four experimental groups: 1st group – HSV-1-infected animals; 2nd – animals consuming high-fat diet (HFD); 3rd – infected animals that were subsequently consuming a high-fat diet (HSV / HFD); 4th – animals consuming a high-fat diet that were subsequently infected with HSV-1 (HFD / HSV) (n = 6); and control group – intact animals. Results: HVS-1 impaired ultrastructural changes in aorta greater than high-fat diet and HVS-1 alone (higher density of lipid inclusions in the subendothelial space, necrosis of endothelial cells), and infection of mice after high-fat diet ended 100% mortality. The formation of atheroma in the aortic wall during HFD was not detected, but the initiative manifestations of atherogenesis have been identified and restricted in the aortic intima. These structural changes included lipid inclusions in the subendothelial space, cell damage and destruction, which lead to an increase cellular detritus in the 3rd (HSV / HFD) group. Conclusions: HSV infection potentiates the accumulation of lipid inclusions in the aortic intima during a HFD, facilitates infection and contributes to the development of acute infection.

Motor disability is a common outcome of spinal cord injury (SCI). The recovery of motor function after injury depends on the severity of neurotrauma; motor deficit can be reversible, at least partially, due to the innate tissue capability to recover, which, however, deteriorates with age. Pain is often a comorbidity of injury, although its prediction remains poor. It is largely unknown whether pain can attend motor dysfunction. Here, we implemented SCI for modelling severe and moderate neurotrauma and monitored SCI rats for up to 5 months post-injury to determine the profiles of both motor deficit and nociceptive sensitivity. Our data showed that motor dysfunction remained persistent after a moderate SCI in older animals (5-month-old); however, there were two populations among young SCI rats (1 month-old) whose motor deficit either declined or exacerbated even more over 4–5 weeks after identical injury. All young SCI rats displayed changed nociceptive sensitivity in thermal and mechanical modalities. The regression analysis of the changes revealed a population trend with respect to hyper- or hyposensitivity/motor deficit. Together, our data describe the phenotypes of motor deficit and pain, the two severe complications of neurotrauma. Our findings also suggest the predictability of motor dysfunction and pain syndromes following SCI that can be a hallmark for long-term rehabilitation and recovery after injury.

The aim: To evaluate muscle changes after sciatic nerve damage with the injection of bone marrow aspirate cells. Materials and methods: 36 rabbits underwent sciatic nerve cross-section and neuroraphy, bone marrow aspirate cells were injected directly or 7 weeks after neuroraphy. Changes in skeletal muscle morphology (photomicrographs of histological sections were analyzed for morphometric analysis of collagen region, quantitative analysis of conducted collagen density and measurement of muscle fibers diameter) and biochemical parameters (catalase activity, superoxide dismutase and glutathione peroxidase measurements and level of TBARS was determined) at 8, 12, and 16 weeks were examined. Results: There is atrophy of muscle fibers in denervated muscles, and it has a negative tendency between 8 and 12 weeks. Delayed bone marrow aspirate cells injection into the muscles at 7 week – delayed atrophy and formation of TBA reactive substances. But bone marrow aspirate cells injection into the muscles directly after neuroraphy increased collagen formation, and development of fibrosis in areas of atrophy. Conclusions: Sciatic nerve injury results in atrophy of muscle tissue, which is partially delayed after delayed bone marrow aspirate cells injection at week 7. Muscle atrophy was characterized by a sharp increase in TBARS levels at 12 and 16 weeks and catalase activity at 12 weeks, and changes in biochemical parameters were partially normalized after the use of cell aspirates, to a greater extent with delayed injection.

The aim of the article was to study changes in periodontal tissues in rats with spontaneous periodontitis (SP) and to evaluate the effect of hyaluronic acid (HA) on the state of the periodontium. Wistar rats with signs of SP were divided into 6 groups: 1) intact group; 2) intact animals with HA "HD-1,0 MDa"; 3) SP group; 4) SP with HA "S-2,4 MDa"; 5) SP with HA "ST-2,4 MDa"; 6) SP with HA "HD-1,0 MDa". The study of the periodontium rats with SP noted the main structural changes (collagen reduction, resorption of alveolar bone, dilatation and stasis of the vessels of the periodontium, gingival papilla and tooth pulp), which were assessed as moderate. Morphological evidence of inflammation was infiltration of neutrophils into the connective tissue of the gums, without the formation of abscesses. Local administration of HA did not cause additional structural damage in periodontal tissues of rats with SP, but also did not affect changes in the microvascular system of periodontium and tooth pulp, periodontal ligaments, only a tendency to inhibit alveolar bone resorption in rats was noted. One can consider the tendency to improve the condition of periodontal tissues in the group of rats injected with high molecular HA and HA with mannitol (2.4 MDa).

Regeneration of the dura mater following duraplasty using a collagen film, a chitosan film, or a combination of both with gelatin, was studied in a craniotomy and penetrating brain injury model in rats. Collagen autofluorescence in the regenerated dura mater was evaluated using confocal microscopy with excitation at λem = 488 nm and λem = 543 nm. An increase in regeneration of the extracellular matrix of connective tissue and an increase in matrix fluorescence were detected at 6 weeks after duraplasty. The major contributors to dura mater regeneration were collagen films, chitosan plus gelatin-based films, and, to a much lesser extent, chitosan-based films. By using autofluorescence densitometry of extracellular matrix, the authors were able to quantify the degree of connective tissue regeneration in the dura mater following duraplasty.

The studies of the properties of vascular structures and tissues during electric welding, in particular direct morphological changes in the blood vessel walls in the areas of welding processes, are of interest. Perforating veins, femoral veins, abdominal aorta, vena cava and porcine perforating veins of the limbs were used in this study. We performed end-to-end electric welding of the aorta, venous end-to-side electric welding, vein end-to-artery side arterial and venous welding, venous end-to-end electric welding, as well as arterial and venous lumen sealing.The results of histological studies showed the formation of a coagulated acellular protein matrix, represented by unorganized denatured protein fibrous structures. In the area of vascular tissue coagulation, lacunes were formed as a result of water evaporation from the biological tissue. In the perifocal area of the welded junction, cell reduction occurred without necrosis or charring. The data obtained confirm the safety of high frequency electric welding of the main vessels and the prospectfor clinical use of the studied techniques.

Spinal cord regeneration after mechanical injury is one of the most difficult biomedical problems. This article evaluates the effect of poly(N-[2-hydroxypropyl]-methacrylamide) hydrogel (PHPMA-hydrogel) on spinal cord regeneration in young rats after lateral spinal cord hemi-excision (laceration) at the level of segments T 12 -T 13 (TrGel group). The locomotor function score (FS) and the paretic hindlimb spasticity score (SS) were assessed according to Basso-Beattie-Bresnahan (BBB) and Ashworth scales, respectively, and compared to a group of animals with no matrix implanted (Tr group). Regeneration of nerve fibers at the level of injury was evaluated at ~5 months after spinal cord injury (SCI). One week after the SCI induction, the FS on the BBB scale was 0.9±0.5 points in the Tr group and 3.6±1.2 points in the TrGel group. In the Tr group, the FS in 5 months was significantly lower than in 2 weeks after SCI, while no significant changes in FS were detected in the TrGel group over the entire observation period. The final FS was 0.8±0.3 points in the Tr group and 4.5±1.8 points in the TrGel group. No significant changes in SS have been observed in the TrGel group throughout the experiment, while the Tr group showed significant increases in SS at 2nd week, 6th week, 3th month and 5th month. The SS in 5 months was 3.6±0.3 points on the Ashworth scale in the Tr group and 1.8±0.7 points in the TrGel group. Throughout the observation period, significant differences in FS between groups were observed only in 5 weeks after SCI, whereas significant differences in SS were observed in 2, 3 and 6-8 weeks post-injury. Glial fibrous tissue containing newly formed nerve fibers, isolated or grouped in small clusters, that originated from the surrounding spinal cord matter have been found between the implanted hydrogel fragments. In conclusion, PHPMA-hydrogel improves recovery of the hindlimb locomotor function and promotes regenerative growth of nerve fibers. Further research is needed to clarify the mechanism of this PHPMA-hydrogel effect.

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