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Clinical efficacy of a composition of nanostructuared silicon dioxide and fosfomycin in treating the skin abscess induced by Staphylococcus aureus inoculation in rabbits has been studied. It is established that the proposed composition of silicon dioxide nanoparticles and fosfomycin exhibits higher therapeutic potential in treating local purulent-septic process in skin of test animals. The therapy with this composition reduced the number of abscesses in the skin by 50% after two days of application and by 80 - 90% after five days of therapy as compared to therapy with application of chloramphenicol liniment (15.0 vs. 4.0 and 7.0 vs. 2.0, respectively).

We have investigated the role of endogenous retroviral mink cell focus-forming (MCF) genes in the regulation of mouse bone marrow hemopoietic progenitor cell proliferation. The p15E protein coded by the MCF env gene is expressed by early hemopoietic progenitors, mostly on spleen colony forming units (CFUs-12) and on erythropoietin-independent erythroid progenitors. Stimulation of cell proliferation in hemopoietic precursors by steroid hormone (testosterone propionate) treatment resulted in upregulation of the expression of the endogenous p15E protein on bone marrow cells. Blocking of endogenous retroviral MCF env gene expression on the activated hemopoietic progenitors by antisense oligonucleotides inhibited their proliferation. These data suggest that the endogenous MCF env genes act as growth-regulators for pluripotent hemopoietic progenitors.

In the present study we investigated production of the peptide of retroviral origin in patients with various types of leukemia. For this purpose the high affinity rabbit antibodies were generated against the synthetic peptide representing the "immunosuppressive motif" within the envelope protein of human endogenous retrovirus type C. The presence of this peptide was identified only in sera of the patients with chronic myelo- and/or promonocytic leukemia at acute phase. Furthermore, the appearance of this protein correlated with agranulocytosis. SDS-PAGE profile revealed the serum protein recognized by Ab that had MW of 88 kDa. However, in bone marrow cells, the same Ab bound 66 kDa peptide, and low molecular weight peptide, INF-agr;, as well. It was determined that 88 kDa protein was a highly glycosylated version of 66 kDa protein. Staining blood cells and bone marrow cells with FITC-labelled specific monoclonal antibodies demonstrated that CD34(+) cells produced this peptide. The appearance of this peptide in sera of patients with myeloid leukemia was considered as unfavorable prognosis since it was followed with lethality in 50% of cases. Thus, besides potential involvement of endogenous retroviral products in carcinogenesis, they may be considered as a factor of immunosuppression.

RAMS, Siberian Branch, has been actively participating for the last 25 years in elaboration and realization of numerous scientifically applied programs aimed at improving diagnosis, treatment, and prophylaxis of the most widespread diseases among the Native and newcoming populations of the Russian Far North (Taimyr, Yakutia, and Chukotka). The medical researchers of different RAMS, Siberian Branch, institutes, based on long-term investigations, have obtained a number of largely new data on etiology, pathogenesis, and epidemiology of cardiovascular, infectious, and cancer disease; diabetes; alcohol addiction; trauma; etc., and have developed practical recommendations for public health institutions on improvement of people's health.

A possible biologic activity of endogenously expressed env sequence of retroviral mink cell focus-forming virus (MCF) genome for hematopoietic colony formation was studied in mice. Antisense 20-mer complementary to MCF env sequence was used to detect the result of blockage of this gene translation on the potency of marrow cells to form colonies of erythroid (BFU-E), myeloid granulocyte-macrophage (CFU-GM), and stem cell (day 11 CFU-S) hematopoietic compartments. A large relative decrease in BFU-E number was found in bone marrow cell cultures preincubated with antisense oligonucleotide during 4 h, whereas CFU-GM colonies remained unaffected. A marked reduction of CFU-S colony formation was also registered under antisense oligomer influence. Following a decreased proliferation of erythroid progenitors, we suggest the mechanism by which antisense oligonucleotide could cause the loss of colony formation. Taken together, these data allow to propose that the expression of this gene is naturally significant for hematopoietic progenitor activity exerting some property of env gene products to regulate the growth of erythroid and multilineage hematopoietic precursors.

The retroviral transmembrane p15E peptide is known to suppress a wide variety of immune cell functions, suggesting a role for immunosuppression associated with retroviral infection. The 10-amino acid sequence from the highly conserved portion of p15E (CKS-10) is capable of reproducing this inhibitory activity. In this study we set out to determine the influence of this decapeptide on murine spleen cell mitogen-induced proliferation and hematopoietic granulocyte-macrophage and erythroid precursor colony formation in vitro. A dose- and time-dependent suppression of spleen cell blastogenic response was produced by the CKS-10 peptide. When bone marrow cells were incubated with decapeptide, the significant decrease of CFU-GM colony number was also dose-dependent. In contrast, the same doses of CKS-10 peptide which induced a most significant inhibition of CFU-GM colony formation caused a marked increase of BFU-E colonies. A most pronounced effect of the peptide on bone marrow hematopoietic progenitor activity was produced by prolonged exposure to the peptide. Given the results of this study, it seems likely that, in addition to the cytopathic effect of retroviruses on the lymphocytes, viral peptide-mediated hematopoiesis disorders may also play an important role in the pathogenesis of immunodeficiency associated with retroviral infections.

The effect of sheep red blood cells (SRBC) and human red blood cells (HRBC) on the number of CFU-S in the bone marrow and spleen of (CBA X C57BL/6)F1 mice tolerant to SRBC was examined. The number of bone marrow and spleen CFU-S in SRBC tolerant mice was increased after injection of HRBC. After challenge with SRBC, CFU-S number was elevated in the spleen but not in the bone marrow. Thus, the mechanism of CFU-S activation in response to antigen exposure is different in the bone marrow and spleen.

The influence of thymus dependent and thymus independent antigens on proliferation of CFU-S in B-mice bone marrow was investigated. The process of CFU-S proliferative activity increases after the injection of both antigens and is mediated in part by B-lymphocytes.

The number of colony forming units in mice following the transplantation of cells of bone marrow, spleen and embryonal liver, forming exogenous spleen colonies on 5, 8 and 11 days has been determined. It has been shown that stem cell subpopulation forming colonies on 5 day (CFUs-5) was notable for lower capacity for self maintenance, and contained predominantly by erythroid colonies, these CFUs-5 were mainly in embryonal liver and less in reduced in the hemopoietic populations in mice.