Experimental Approaches to Scar Modeling through Mechanical Skin Damage and Chemical Burn in Sprague Dawley Rats.

Creating of a scar model in laboratory animals is the most acceptable option for the preclinical search of scar treatment. However, due to high skin regeneration rate in laboratory rodents, creating an optimal animal model of scar formation is a challenge. Here we describe five methods for modeling a scar tissue in rats that we have tested. These methods allowed achieving different histopathological features and different stages of skin scar formation.

Selective targeting of α7 nicotinic acetylcholine receptor by synthetic peptide mimicking loop I of human SLURP-1 provides efficient and prolonged therapy of epidermoid carcinoma in vivo.

α7-Type nicotinic acetylcholine receptor (α7-nAChR) promotes the growth and metastasis of solid tumors. Secreted Ly6/uPAR-Related Protein 1 (SLURP-1) is a specific negative modulator of α7-nAChR produced by epithelial cells. Here, we investigated mechanisms of antiproliferative activity of recombinant SLURP-1 in epidermoid carcinoma A431 cells and activity of SLURP-1 and synthetic 21 a.a. peptide mimicking its loop I (Oncotag) in a xenograft mice model of epidermoid carcinoma. SLURP-1 inhibited the mitogenic pathways and transcription factors in A431 cells, and its antiproliferative activity depended on α7-nAChR. Intravenous treatment of mice with SLURP-1 or Oncotag for 10 days suppressed the tumor growth and metastasis and induced sustained changes in gene and microRNA expression in the tumors. Both SLURP-1 and Oncotag demonstrated no acute toxicity. Surprisingly, Oncotag led to a longer suppression of pro-oncogenic signaling and downregulated expression of pro-oncogenic miR-221 and upregulated expression of KLF4 protein responsible for control of cell differentiation. Affinity purification revealed SLURP-1 interactions with both α7-nAChR and EGFR and selective Oncotag interaction with α7-nAChR. Thus, the selective inhibition of α7-nAChRs by drugs based on Oncotag may be a promising strategy for cancer therapy.

CSF - injected contrast medium enhances post-traumatic spinal cord cysts. An experimental study in rats.

OBJECTIVE: Spinal cord injury (SCI) is still one of the most challenging problems in neurosurgical practice. One of the major obstacles to neural regeneration following trauma is the formation of glial scarring and post-traumatic cysts which acts against proper growth of axons through the site of injury. Cerebrospinal fluid (CSF) delivery of bioactive agents into cystic cavities could represent a promising therapeutic strategy. In the present study, we investigated specifically the dynamics of intradural delivery of contrast medium and its relocation into post-traumatic cysts in an experimental model of spinal cord cryoinjury in rats. MATERIALS AND METHODS: 32 male Sprague Dawley SPF rats were submitted to injury as previously described. Omnipaque-240 was injected either into the cisterna magna or at the level of the cauda equina. Subsequently, cerebral CT scan examinations were performed in order to check the CSF dynamics of the contrast medium. RESULTS: There was a steady accumulation of contrast medium into post-traumatic cysts as early as five minutes after injection. A dosage of 65 mg of iodine per kilogram ensured an adequate feeling of the cysts at an average of 30 minutes. CONCLUSIONS: Our data indicate that intraspinal injection of bioactive agents can easily reach the site of injury and fill post-traumatic cysts. This could represent an interesting potential therapeutic protocol for SCI.

Modeling of Chronic Lung Inflammation in Rats by Repeated Intratracheal Administration of LPS.

A model of a chronic lung inflammation in SPF Sprague-Dawley rats was developed by repeated intratracheal administration of LPS in a dose of 0.4 mg/kg. On day 22 of the study, male rats treated with LPS have relative monocytopenia and reduced mean concentration of hemoglobin in the erythrocyte and the mean platelet volume in comparison with the control animals (saline). Intratracheal administration of LPS induced an inflammatory process in the lungs characterized by focal atelectasis, compensatory emphysematous expansion of subpleural pulmonary acini, focal mononuclear and neutrophilic perivascular and peribronchial infiltration, and minor focal mononuclear and neutrophilic infiltration of the alveolar walls. Against the background of LPS administration, germinal centers appeared in the lymphoid follicles of the white pulp of the spleen, and focal mononuclear infiltration of the tracheal mucosa and/or submucosa was observed in some animals.

A new mouse unilateral model of diffuse alveolar damage of the lung.

OBJECTIVE AND DESIGN: The existing biological models of diffuse alveolar damage (DAD) in mice have many shortcomings. To offset these shortcomings, we have proposed a simple, nonsurgical, and reproducible method of unilateral total damage of the left lung in ICR mice. This model is based on the intrabronchial administration of a mixture of bacterial lipopolysaccharide (LPS) from the cell wall of S. enterica and α-galactosylceramide (inducing substances) to the left lung. METHODS: Using computer tomography of the lungs with endobronchial administration of contrast material, we have been able to perform an operative intravital verification of the targeted delivery of the inducer. The model presented is characterized by more serious and homogeneous damage of the affected lung compared to the existing models of focal pneumonia; at the same time, our model is characterized by longer animal survival since the right lung remains intact. RESULTS: The model is also characterized by diffuse alveolar damage of the left lung, animal survival of 100%, abrupt increases in plasma levels of TNFa, INFg, and IL-6, and significant myocardial overload in the right heart. It can be used to assess the efficacy of innovative drugs for the treatment of DAD and ARDS as the clinical manifestations that are developed in patients infected with SARS-CoV-2. Morphological patterns of lungs in the noninfectious ("sterile") model of DAD induced by LPS simultaneously with α-galactosylceramide (presented here) and in the infectious model of DAD induced by SARS-CoV-2 have been compared. CONCLUSION: The DAD model we have proposed can be widely used for studying the efficacy of candidate molecules for the treatment of infectious respiratory diseases, such as viral pneumonias of different etiology, including SARS-CoV-2.

α-Conotoxin RgIA and oligoarginine R8 in the mice model alleviate long-term oxaliplatin induced neuropathy.

Оligoarginines were recently discovered (Lebedev et al., 2019 Nov) as a novel class of nicotinic acetylcholine receptors (nAChRs) inhibitors, octaoligoarginine R8 showing a relatively high affinity (44 nM) for the α9/α10 nAChR. Since the inhibition of α9/α10 nAChR by α-conotoxin RgIA and its analogs is a possible way to drugs against neuropathic pain, here in a mice model we compared R8 with α-conotoxin RgIA in the effects on the chemotherapy-induced peripheral neuropathy (CIPN), namely on the long-term oxaliplatin induced neuropathy. Tests of cold allodynia, hot plate, Von Frey and grip strength analysis revealed for R8 and α-conotoxin RgIA similar positive effects, expressed most prominently after two weeks of administration. Histological analysis of the dorsal root ganglia sections showed for R8 and RgIA a similar partial correction of changes in the nuclear morphology of neurons. Since α9/α10 nAChR might be not the only drug target for R8, we analyzed the R8 action on rat TRPV1 and TRPA1, well-known nociceptive receptors. Against rTRPV1 at 25 µM there was no inhibition, while for rTRPA1 IC50 was about 20 µM. Thus, involvement of rTRPA1 cannot be excluded, but in view of the R8 much higher affinity for α9/α10 nAChR the latter seems to be the main target and the easily synthesized R8 can be considered as a potential candidate for a drug design.

Comparison of Biochemical Parameters and Pathomorphological Changes in Rats Receiving Standard and High-Fat Diets during Modeling of Streptozotocin Diabetes.

The use of a high-fat diet, along with streptozotocin administration, can provide more profound insight into the mechanism of development of complications in diabetes, as well as their treatment. High-fat diet given over 3 weeks before intraperitoneal injection of streptozotocin in a dose of 40 mg/kg promoted the appearance of hyperglycemia in Wistar rats. The biochemical analysis of blood serum revealed increased levels of urea, triglycerides, cholesterol, AST, ALT, and concentration of inorganic phosphates and K+ ions in the high-fat diet group in comparison with the control. Both the biochemical analysis of the blood and histological analysis showed more pronounced abnormalities in rats receiving high-fat diet in comparison with animals receiving standard ration. These changes are the early markers for the development of nephropathy, impaired liver function, and microvascular disorders typical of patients with diabetes mellitus.

In vivo monitoring of vascularization and oxygenation of tumor xenografts using optoacoustic microscopy and diffuse optical spectroscopy.

The research is devoted to comparison of the blood vessel structure and the oxygen state of three xenografts: SN-12C, HCT-116 and Colo320. Differences in the vessel formation and the level of oxygenation are revealed by optoacoustic (OA) microscopy and diffuse optical spectroscopy (DOS) respectively. The Colo320 tumor is characterized by the highest values of vessel size and fraction. DOS showed increased content of deoxyhemoglobin that led to reduction of saturation level for Colo320 as compared to other tumors. Immunohistochemical (IHC) analysis for CD31 demonstrates the higher number of vessels in Colo320. The IHC for hypoxia was consistent with DOS results and revealed higher values of the relative hypoxic fraction in Colo320.

[NATURAL THERAPEUTIC FACTORS IN MEDICAL REHABILITATION OF PATIENTS WITH POST-COVID-19 AT OUTPATIENT TREATMENT STAGE].

The purpose of the research is to study therapeutic efficiency of medical rehabilitation of patients with Post-COVID-19 syndrome at outpatient treatment stage including natural therapeutic factors and phyto products in rehabilitation programme. In Nalchik resort 64 patients suffering from corona virus disease COVID-19 have been examined. They were distributed into 2 groups. 30 patients of the group of comparison were prescribed mineral water «Nalchik¼, exercise therapy, foam cocktails and rectal suppositories with thick licorice root extract. 34 patients of the main group additionally had natural aeroionophyto therapy along the route of mid-mountain natural park of Nalchik resort in combination with exercise therapy and group psychotherapy in park curative grounds and nitrogen thermal baths. The effectiveness was assessed with the help of the scale «Medical Research Council¼ (mMRC), the level of glycyrrhic acid in blood serum, functional tests, cardiointervalography in dynamics. The conducted comparative analysis proved the ability of natural therapeutic factors to influence the main life-supporting body systems positively. Therefore, the patients of the main group had a reduction of apnea by 29,4% (p<0,01) in comparison with the primary data, increase in adaptation capacity, on average, by 42,4% (p<0,01), improvement of physical activity, on average, by 36,2% (p<0,01), normalization of hemodynamic parameters. It was significantly better (by 20-25%, p<0,05) compared to the treatment in the group of comparison. There has been developed a new method of medical rehabilitation of patients with Post-COVID-19 syndrome at outpatient treatment stage including phytotherapy with licorice root extract and natural aeroionophyto therapy, exercise therapy, psychotherapy along the route of mid-mountain natural park in Nalchik resort, which significantly promotes (p<0,05) optimization of rehabilitation activities.

Effect of Standard and High-Fat Diets during Modeling of Streptozotocin-Induced Diabetes in Rats on the Development of Complications.

For evaluation of the effect of high-fat diet on the development of diabetic complications, the rats were maintained on standard or high-fat diet. In 3 weeks, diabetes mellitus was modeled by single intraperitoneal injection of streptozotocin. Changes in hematological parameters, physical and biochemical parameters of the urine, and in the development of thermal allodynia were different after 15-week standard and high-fat diets.

[Comparative effectiveness of complex physiotherapeutic treatment of patients in the early stages of avascular necrosis of the femoral head]. / Sravnitel'naya effektivnost' kompleksnogo fizioterapevticheskogo lecheniya bol'nykh na rannikh stadiyakh asepticheskogo nekroza golovki bedrennoi kosti.

INTRODUCTION: In the late stages of avascular necrosis of the femoral head (ANFH), total hip arthroplasty (THA) is a non-alternative treatment method. In the early stages, methods of conservative treatment show some effectiveness. Among them, most often there is evidence of the effectiveness of physiotherapy options. AIM: Of this study is the development and study of a method of complex non-surgical treatment of ANFH based on a combination of physiotherapy and phytotherapy methods. MATERIAL AND METHODS: We examined 60 patients with early stages of ANFH, who underwent courses of complex treatment. Patients of the primary group received a complex, including: exposure to acupuncture points in the area of hip joint (HJ) with low-frequency currents using the Osteon-1 apparatus in combination with phytoapplications, HJ massage, special physiotherapy exercises. Unloading the HJ (walking on crutches) was mandatory component. Patients in the control group were treated using a complex including: manual massage of HJ, the use of sinusoidally modulated currents and ultraphonophoresis of hydrocortisone on the affected joint. In order to assess the dynamics of the clinical and functional state of HJ before and after the treatment, Harris questionnaire, radiography, ultrasound densitometry, and laser Doppler imaging were used. Quality of life was assessed using the SF36 questionnaire. The full course of treatment was 1 month. Long-term results were studied after 1 year by the questionnaire method. RESULTS: In patients of both groups, a positive dynamics of the clinical and functional state of the joints was registered, but higher statistically significant indicators were obtained in the primary group. Moreover, in a significant number of patients (in 95% of cases), positive clinical results persisted throughout the year. CONCLUSION: The use of a complex of treatment based on physiotherapy and a combination of physiotherapy and phytotherapy makes it possible for us to obtain positive clinical and functional dynamics of the state of the joints and an increase in the quality of life in patients with ANFH.

Mouse Model for Assessing the Subchronic Toxicity of Organophosphate Pesticides.

The development of antidotes to organophosphate poisons is an important aspect of modern pharmacology. Recombinant acetylcholinesterase and butyrylcholinesterase are effective DNA-encoded acceptors of organophosphate poisons and, in particular, pesticides. Here, we present the results of a study on the effectiveness of recombinant butyrylcholinesterase (BChE) in modeling organophosphate poisoning caused by oral administration of paraoxon at a dose of 2 mg / kg. The study showed a high activity of BChE as a protective agent for subchronic anticholinesterase poisoning in an in vivo model. The administration of BChE in a dose of 20 mg / kg allows one to avoid mortality, and also contributed to rapid recovery after model poisoning.

[Approaches for formation of the large bowel anastomoses for prophylaxis of their sutures insufficiency].

The results of surgical treatment of 424 patients, in whom the postponed and elective surgery was done for the large bowel malignancies, were analyzed. Advantages of a one-layer suture while formation of a large-bowel anastomoses in comparison with a two-layer suture were noted: minimal rate of the sutures insufficiency--(4.9 +/- 0.8)%, and (7.9 +/- 1.7)%, accordingly (p<0.001). Mostly often insufficience of the colorectal anastomosis sutures was observed after anterior rectal resection--in (9.7 +/- 1.9)% and (7.2 +/- 1.5)% patients. Postoperative lethality was 2.6%, for majority of the patients the reasons of the death were pulmonary thromboembolism and an acute cardio-vascu- lar insufficiency.

[Exploration and identification of Physcomitrella patens moss peptides].

In the current study the isolation and identification of Physcomitrella patens (Hedw.) B.S.G. moss peptides are described. Physcomitrella patens moss is actively used in recent years as a model organism to study the biology of plants. Protoplasts, protonemata and gametophores of the moss are demonstrated for the first time to contain diverse small peptides. From gametophores was isolated and identified 58 peptides that are fragments of 14 proteins, and from protonemata - 49 peptides, fragments of 15 proteins. It was found that the protonemata and gametophores Ph. patens, which are the successive stages of development of this plant, significantly different from each other as a peptide composition and the spectrum of the precursor protein of identified peptides. Isolation of protoplasts of the enzymatic destruction of cell wall protonemata accompanied by massive degradation of intracellular proteins, many of whom are proteins of photosynthesis, which is a characteristic response of plants to stress the impact of environmental factors. A total of moss protoplasts were isolated and identified 323 peptides that are fragments of 79 proteins.

[Quantitative estimation of the perception of the frequency of tonal sounds by human].

The possibility of a purely instrumental investigation of the sensory characteristics of human in the real time scale has been shown using an analyzer of tonal hearing as an example. In accordance with the previously developed approach, the mean-square errors of the deviation of the instantaneous frequency of tonal sounds from its average value upon their vocal reproduction by persons being tested as well as upon their reproduction by a special electronic sound generator requiring a continuous comprehended regulation for maintaining the wanted frequency were chosen as these characteristics. It was found that the mean-square deviation of the current reproducible frequency linearly depends on the average frequency of the reproducible tonal sound. The method can be used without radical changes for studying the characteristics of human sensory analyzers with the use of stimuli of other modalities to control the state of the sensory sphere of the human operator, to solve the problems of the synthesis of human--machine interfaces, and to construct "virtual reality" systems.

[Variation of BM224 microsatellite in green frogs of the genus Rana].

The variable microsatellite repeat BM224 has been discovered in the genomes of eight species of green frogs (Rana ridibunda, R. cf bedriagae, R. cretensis, R. esculenta, R. lessonae, R. shquiperica, R. saharica, R. nigromaculata). Earlier, this repeat had been observed in members of the genus Bufo. In this paper, a possibility of usage of this genetic marker for species identification is discussed.