[Antiviral activity of basidial fungus Inonotus obliquus aqueous extract against SARS-CоV-2 virus (Coronaviridae: Betacoronavirus: Sarbecovirus) in vivo in BALB/c mice model].

INTRODUCTION: The COVID-19 pandemic combined with seasonal epidemics of respiratory viral diseases requires targeted antiviral prophylaxis with restorative and immunostimulant drugs. The compounds of natural origin are low-toxic, but active against several viruses at the same time. One of the most famous compounds is Inonotus obliquus aqueous extract. The fruit body of basidial fungus I. obliquus is called Chaga mushroom. The aim of the work ‒ was to study the antiviral activity of I. obliquus aqueous extract against the SARS-CoV-2 virus in vivo. MATERIALS AND METHODS: Antiviral activity of I. obliquus aqueous extract sample (#20-17) was analyzed against strain of SARS-CoV-2 Omicron ВА.5.2 virus. The experiments were carried out in BALB/c inbred mice. The SARS-CoV-2 viral load was measured using quantitative real-time PCR combined with reverse transcription. The severity of lung tissue damage was assessed by histological methods. RESULTS: The peak values of the viral load in murine lung tissues were determined 72 hours after intranasal inoculation at dose of 2,85 lg TCID50. The quantitative real-time PCR testing has shown a significant decrease in the viral load compared to the control group by 4,65 lg copies/ml and 5,72 lg copies/ml in the lung tissue and nasal cavity samples, respectively. Histological methods revealed that the decrease in the number and frequency of observed pathomorphological changes in murine lung tissues depended on the introduction of the compound under study. CONCLUSION: The results obtained indicate the possibility of using basidial fungus Inonotus obliquus aqueous extract as a preventive agent against circulating variants of SARS-CoV-2 virus.

[Ultrastructure of epidermocytes in true pemphigus acantholysis]. / Ul'trastruktura épidermotsitov pri istinnoi akantoliticheskoi puzyrchatke.

OBJECTIVE: To investigate the ultrastructure of epidermocytes in skin biopsy specimens, by taking into account an update on the pathomorphogenesis of true pemphigus acantholysis. MATERIAL AND METHODS: Affected skin biopsy specimens from 4 patients with Pemphigus vulgaris (a mixed mucosal-epidermal variant) and from 1 patient with P. foliaceus at the onset of the disease in the absence of therapy were examined by light microscopy of semifine sections and by transmission electron microscopy. RESULTS: Skin biopsy specimens from pemphigus patients from the foci with a positive Nikolsky's sign were characterized by acantholysis and dilated intercellular spaces in the basal and spinous layers of the epidermis in combination with desmosomal hypoplasia and destruction. The reduction in the organelles of mitochondrial protein synthesis, which causes a decrease in the cytoplasm of the perikaryon and especially in the processes of a number of tonofilaments involved in the formation of desmosomes engaged our attention when studying the ultrastructure of epidermocytes. CONCLUSION: A marked reduction in the number and size of desmosomes in P. vulgaris and P. foliaceus starts in the basal layer of the epidermis; however, acanthosis occurs in the suprabasal and spinous layers, respectively. The universal manifestations of pathology of cytoskeletal elements involved in the formation of desmosomes, as well as their underproduction must be considered in the concept of the pathogenesis of true pemphigus acantholysis.

[Inherited epidermolysis bullosa]. / Vrozhdennyi bulleznyi épidermoliz.

OBJECTIVE: To summarize an update on epidermolysis bullosa as a polymorphic group of inherited diseases with a failure of epidermal-dermal integrity. Emphasis is placed on the role of transmission electron microscopy in diagnosis and search directions for new types of the abnormality and its molecular markers. Despite numerous mutations in the genes encoding the components of desmosomes and epithelial basement membrane, the stereotyped manifestations of pathological processes in the group of epidermolysis bullosa have been identified. The paper gives a positive result of cell and gene therapies used by European scientists in the treatment of a 7-year-old child with borderline epidermolysis bullosa, which opens up new prospects for patients with butterfly disease that has long been considered fatal.

Using the Ground Squirrel (Marmota bobak) as an Animal Model to Assess Monkeypox Drug Efficacy.

In experiments to study the sensitivity of ground squirrels (Marmota bobak) to monkeypox virus (MPXV) at intranasal challenge, expressed pox-like clinical symptoms (hyperthermia, lymphadenitis, skin rash all over the body and mucous membranes and others) were observed 7-9 days post-infection. The 50% infective dose (ID50 ) of MPXV for these marmots determined by the presence of clinical signs of the disease was 2.2 log10 PFU. Some diseased marmots (about 40%) died 13-22 days post-infection, and the mortality rate was weakly dependent on MPXV infective dose. Lungs with trachea were primary target organs of marmots challenged intranasally (with ~30 ID50 ). The pathogen got to secondary target organs of the animals mainly via the lymphatic way (with replication in bifurcation lymph nodes). Lungs with trachea, nasal mucosa and skin were the organs where the maximum MPXV amounts accumulated in these animals. Evidences of the pathogen presence and replication were revealed in these and subcutaneously infected marmots in the traditional primary target cells for MPXV (macrophages and respiratory tract epitheliocytes), as well as in some other cells (endotheliocytes, plasmocytes, fibroblasts, reticular and smooth muscle cells). Our use of this animal species to assess the antiviral efficacy of some drugs demonstrated the agreement of the obtained results with those described in scientific literature, which opens up the prospects of using marmots as animal models for monkeypox to develop therapeutic and preventive anti-smallpox drugs.

[EVALUATION OF THE HUMAN SENSITIVITY TO SMALLPOX VIRUS BY THE PRIMARY CULTURES OF THE MONOCYTE-MACROPHAGES].

Studies of the primary cultures of granulocytes, mononuclear, and monocyte-macrophage cells derived from human blood were performed using variola virus (VARV) in the doses of 0.001-0.021 PFU/cell (plaques-forming units per cell). Positive dynamics of the virus accumulation was observed only in the monocyte-macrophages with maximum values of virus concentration (5.0-5.5 Ig PFU/ml) mainly within six days after the infection. The fact of VARV replication in the monocyte-macrophages was confirmed by the data of electron microscopy. At the same time, virus vaccines when tested in doses 3.3 and 4.2 Ig PFU/ml did not show the ability to reproduce in these human cells. The people sensitivity to VARV as assessed from the data obtained on human monocyte-macrophages corresponded to -1 PFU (taking into account the smooth interaction of the virus in the body to the cells of this type), which is consistent to previously found theoretical data on the virus sensitivity. The human susceptibility to VARV assessed experimentally can be used to predict the adequacy of developed smallpox models (in vivo) based on susceptible animals. This is necessary for reliable assessment of the efficiency of development of drugs for treatment and prophylaxis of the smallpox.

[THE USE OF THE MODEL MOUSE ICR--VARIOLA VIRUS FOR EVALUATION OF ANTIVIRAL DRUG EFFICACY].

Mice of the ICR outbred population were infected intranasally (i/n) with the variola virus (VARV, strain Ind-3a). Clinical signs of the disease did not appear even at the maximum possible dose of the virus 5.2 lg PFU/head (plaque-forming units per head). In this case, 50% infective dose (ID50) of VARV estimated by the presence or absence of the virus in the lungs three days after infection (p.i.) was equal to 2.7 ± 0.4 lg PFU/head. Taking into account the 10% application of the virus in the lungs during the intranasal infection of the mice, it was adequate to 1.7 lg PFU/lungs. This indicates a high infectivity of the VARV for mice comparable to its infectivity for humans. After the i/n infection of mice with the VARV at a dose 30 ID50/ head the highest concentration of the virus detected in the lungs (4.9 ± 0.0 lg PFU/ml of homogenate) and in nasal cavity tissues (4.8 ± 0.0 lg PFU/ml) were observed. The pathomorphological changes in the respiratory organs of the mice infected with the VARV appeared at 3-5 days p.i., and the VARV reproduction noted in the epithelial cells and macrophages were noticed. When the preparations ST-246 and NIOCH-14 were administered orally at a dose of 60 µg/g of mouse weight up to one day before infection, after 2 hours, 1 and 2 days p.i., the VARV reproduction in the lungs after 3 days p.i. decreased by an order of magnitude. Thus, outbred ICR mice infected with the VARV can be used as a laboratory model of the smallpox when evaluating the therapeutic and prophylactic efficacy of the antismallpox drugs.

The Possibility of Using the ICR Mouse as an Animal Model to Assess Antimonkeypox Drug Efficacy.

As a result of the conducted experimental studies on intranasal challenge of ICR mice, rabbits and miniature pigs (even in the maximum variant) with the doses of 4.0-5.5 lg PFU of monkeypox virus (MPXV), some clinical signs such as purulent conjunctivitis, blepharitis and ruffled fur were found only in mice. The 50% infective dose (C ID50 ) of MPXV for these animals estimated by the presence of external clinical signs was 4.8 lg PFU, and L ID50 estimated by the virus presence in the lungs of mice 7 days post-infection taking into account its 10% application in the animal respiratory tract was 1.4 lg PFU. When studying the dynamics of MPXV propagation in mice challenged intranasally with 25 L ID50 of MPXV, the maximum pathogen accumulation was revealed in nasal cavity, lungs and brain: 5.7 ± 0.1, 5.5 ± 0.1 and 5.3 ± 0.3 lg PFU/ml, respectively. The pathomorphological examination of these animals revealed the presence and replication of the pathogen in the traditional primary target cells for MPXV (mononuclear phagocyte system cells and respiratory tract epitheliocytes) as well as in some other types of cells (endothelial cells, reticular cells, connective tissue cells). Our use of these animals to assess the antiviral efficacy of some drugs demonstrated the agreement of the results (a significant positive effect of NIOCH-14 and ST-246) with those described in scientific literature, which opens up the prospects of using ICR mice as animal models for monkeypox to develop preventive antismallpox drugs.

[The influence of glucocorticoid immunosuppression on the course of experimental influenza pneumonia].

The study demonstrates the effects of kenalog (Kn), a synthetic glucocorticoid hormone, on the course of virus A/Aichi/2/68 influenza in white mice. In doses of 5 and 10 mg/kg, Kn reduced the weight of the adrenal glands, thymus and spleen, which was accompanied by decrease of the resistance to the mentioned virus, judging by LD50 decrease vs. this index in the control infected group. Besides, four days after infecting with 5 LD50 of influenza virus (IV), lung virus and interferon titers were significantly lower in mice pretreated with Kn vs. mice treated with placebo. Lung cell susceptibility to IV in vitro was identical in mice treated with Kn or placebo. In ultrathin lung sections of IV-infected mice, both experimental and control ones, there was virus budding in bronchial epithelium cells and type I and II alveolocytes. Analysis of inflammatory effusion compound in semithin lung sections 6 days after IV infection, found a substantially smaller number of mature alveolar macrophages (AM) and a bigger number of neutrophiles vs. infected controls. The authors reckon that higher mortality of mice pretreated with Kn before infecting, is caused not by enhancement of IV reproduction in target lung cells during influenza development, but by the contribution of other pathogenic factors. One of those may be increase of neutrophilic migration into the lungs; neutrophiles are more able to realize their significant destructive potential under the condition of reduction in the clearing function of AM and IV infection.

[The study of markers of herpes virus infections in myocardial ischemia].

A group of patients with ischemic heart disease (IHD), who underwent surgical aorta-coronary vascular shunting, was examined in this investigation. Low titers of HSV-1 specific IgG were detected in all patients, the obtained values being consistent with similar data obtained in healthy subjects of the same age. Negative PCR of HSV-I DNA in blood and biopsy results were obtained. None of the patients demonstrated typical clinical pattern of infectious disease caused by herpes simplex virus. These data are evidence of the absence of the HSV-1 correlation with coronary atherosclerosis in patients with the IHD diagnosis. The significance of HCMV specific IgG titers and HCMV DNA detected in blood plasma in 87.7% cases is probably attributed to existence of connection of HCMV infection markers revealing in patient' blood with IHD diagnosis and coronary atherosclerosis. Besides, the HCMV DNA presence in biopsy taken from myocardium or vascular wall with lesion is revealed in 100% cases. The cytomegalovirus markers in tissue lesions with the help of specific antiserums marked to HSMV recombinant proteins are also revealed in 100% cases. This fact indicates the connection between pathological atherosclerotical process in IHD and cytomegalovirus infection.

[Study of the antiviral activity, pharmacokinetics and toxic properties of liposomal form of human alpha-2b interferon administered topically]. / Izuchenie protivovirusnoi aktivnosti, farmakokinetiki i toksicheskikh svoistv liposomal'noi formy rekombinantnogo alfa-2b-interferona cheloveka pri naruzhnom primenenii.

Human liposomal recombinant alpha 2b-interferon topically applied to laboratory animals was tested for antiviral activity, pharmacokinetics, and toxicity. The interferon was shown to penetrate through the skin and to circulate in the blood of experimental animals longer than its injectable form, and to exhibit its antiviral activity against genital herpes in guinea pigs. It produced no toxic, skin-irritant, or allergic effects in laboratory animals.

[The role of chronic colitis in the pathogenesis of Hirschsprung 's disease in children]. / Rol' khronicheskogo kolita v patogeneze bolezni Girshprunga u detei.

The role of chronic colitis in pathogenesis of Hirschsprung's disease was studied ultrastructurally and morphometrically. Morphological features of chronic colitis were revealed by examination of full-layers biopsies and excised fragments of the colon in 26 children aged from 2 to 14 years with Hirschsprung's disease. Atrophic-sclerotic form of colitis develops in various disturbances of colo-rectal innervation. In this condition diffuse sclerosis of bowel wall could be considered as pathognomonic symptom of Hirschsprung's disease. As a result of development of sclerosis insufficiency of the bowel motor function increases.

[Experimental study of therapeutical properties and safety of king crab collagenase-containing ointment]. / Eksperimental'noe izuchenie lechebnykh svoistv mazi, soderzhashchei kollagenazu kamchatskogo kraba.

The effects of ointment containing king crab (Paralithodes camtschatica) collagenase on intact skin, thermal, and pyonecrotic wounds were studied in rats by using hematological, biochemical, immunological, and morphological methods. The ointment for the skin and viscera was shown to be safe. It is highly effective in debriding the infected wounds. Different concentrations of collagenase were tested. The concentration of collagenase was recommended to be 0.2 mg/g ointment for use.

[Enhancement of epidermal regeneration by recombinant vaccinia virus growth factor]. / Usilenie épidermal'noi regeneratsii s pomoshch'iu rekombinantnogo faktora rosta virusa ospovaktsiny.

Examining the specific activity has showed that recombinant vaccinia virus growth factor binds to appropriate receptors on the A-431 cell surface and prompts the healing acceleration of degree III burns in rats. This recombinant factor did not demonstrate pyrogenicity or toxicogenicity in tests on rabbits, guinea-pits, noninbred albino mice.

[Ultrastructural analysis of pathological changes in ferrets with experimental canine distemper]. / Ul'trastrukturnyi analiz patologicheskikh izmenenii pri éksperimental'noi chume plotoiadnykh u khor'kov.

Morphologic study of the lungs, liver, spleen, and kidneys of ferrets infected with canine distemper virus has been carried out. Electron microscopy revealed virus reproduction in bronchial epithelial cells, types I and II alveolocytes, bile duct epitheliocytes, and hepatocytes. Mononuclear phagocyte system cells infected with the virus were found in all the examined organs. The most expressed pathological changes were observed in the lungs.

[Ultrastructural and radioautographic research on the skin in acantholysis bullosa]. / Ul'trastrukturnoe i radioavtograficheskoe issledovaniia kozhi pri akantoliticheskoi puzyrchatke.

By means of light microscopy 145 biopsies of skin in acantholytic pemphigus were studied. Electron microscopic and radioautographic study was carried out in 19 cases. It was determined that the whole complex of ultrastructural changes in epidermocytes (impairment of nucleolar apparatus, lysis of cytoplasmic organelles, disappearance of desmosomes) reflects the disturbance of protein synthesis. Radioautographic study in vitro with 3H-uridine and 3H-thymidine revealed the low level of RNA and DNA synthesis in epidermal cells in pemphigus. The data obtained were interpreted with a position from the conception of plastic deficiency.