Water Immersion as a Model of Hypogravity.

We studied the effects of hypogravity modeled by water immersion on cognitive functions and physiological parameters of monkeys. Cognitive capacities of monkeys were evaluated using computer-controlled joystick task with food reward in case of target hit. Water immersion (3 days for 3 h) affected in cognitive functions, body temperature, and blood parameters. The intensity of changes depended on the type of monkey behavior. In animals with non-aggressive behavior, the number of target hits did not decrease after water immersion, and even slightly increased. On the contrary, aggressive monkeys showed poorer test performance. Body temperature after each cycle of water immersion was decreased slightly in non-aggressive monkeys, while in aggressive animals, the changes were significant. At the same time, changes in the erythrocyte count, hemoglobin concentration, and hematocrit were significant in non-aggressive monkeys. Our results are in line with previous data performed on BION biosatellites and correspond to changes of physiological parameters in astronauts during space flights.

Development of a motor and somatosensory evoked potentials-guided spinal cord Injury model in non-human primates.

Background Nonhuman primates (NHP) may provide the most adequate (in terms of neuroanatomy and neurophysiology) model of spinal cord injury (SCI) for testing regenerative therapies, but bioethical considerations exclude their use in severe SCI. New Method A reproducible model of SCI at the lower thoracic level has been developed in Rhesus macaques. The model comprises surgical resection of 25% of the spinal cord in the projection of the dorsal funiculus and dorsolateral corticospinal pathways, controlled via registration of intraoperative evoked potentials (EPs). The animals were evaluated using the modified Hindlimb score, MRI, SSEP, and MEP over a time period of 8-12 weeks post-SCI, followed by histological examination. Results Complete disappearance of intraoperative EPs from distal hindlimb muscles without restoration within two weeks post-SCI was an indicator for irreversible disruption of the abovementioned pathways. As a result, controlled damage to the spinal cord was achieved in three NHPs, clinically manifested as irreversible lower monoplegia. No significant functional restoration was observed in these NHPs up to 12 weeks post-SCI. Demyelination of the damaged ascending tracts was detected. Disturbances in pelvic organ function were not observed in all animals. Comparison with existing methods The new method of EPs-guided SCI allows a more controlled and irreversible damage to the spinal cord compared with contusion and other transection approaches. Conclusions This method to induce complete SCI in NHP is well tolerated, reproducible and ethically acceptable: these are valuable attributes in a preclinical model that will hopefully help advance testing of new regenerative therapies in SCI.

Functional Parameters of Physiological Systems of Laboratory Primates after Administration of Doxorubicin and Transplantation of Mesenchymal Stem Cells.

We studied physiological parameters of rhesus monkeys after administration of anthracycline antibiotic doxorubicin. Intravenous administration of the drug caused intoxication manifested in in an abrupt body weight loss, baldness, vomiting, and exicosis. Intoxication in monkeys determined by the damaging effects of doxorubicin on organs and tissues is also characterized by significant changes in the blood: leukopenia, thrombocytopenia, neutropenia, monocytopenia, lymphocytosis, and a sharp drop of CD20+ B cell content. The total protein and albumin content in the blood significantly decreased. A sharp increase in C-reactive protein was also accompanied by an increase in activity of proinflammatory cytokine IL-6. Transplantation of mesenchymal stem cells in some cases can significantly alleviate doxorubicin-induced damage to organs and maintain normal clinical status of monkeys after two injections of the drug. Late transplantation of stem cells does not have a protective effect and does not protect the animals from the damaging effects of doxorubicin. We found that the protective effect of mesenchymal stem cells depends on the dose of the drug, total number of cells, and the time of their transplantation. It should be noted that human and monkey mesenchymal stem cells produce similar regenerative effects, at least in the doxorubicin toxicity model.

Use of Mesenchymal Stem Cells for Possible Repair of Doxorubicin-Damaged Organs and Tissues in Experimental Monkeys.

Three injections of doxorubicin to rhesus macaques cause severe intoxication, characterized by anemia, cachexia, and degeneration of the viscera. The life span of monkeys injected with the drug and receiving after 24 h mesenchymal stem cell transplantation varied from 96 to 120 days in comparison with 50-74 days in animals receiving stem cells before doxorubicin. Controls received doxorubicin and saline; the lifespan of one monkey was 24 days, of the other - 1 year and 8 months. The increase in activity of proinflammatory cytokine IL-6 was paralleled by an increase in the level of C-reactive protein.

Transplantation of Simian Mesenchymal Stem Cells to Baboons with Experimentally Induced Myocardial Infarction.

Culture of mesenchymal stem cells isolated from the bone marrow of primates by their characteristics met the requirements of stem cells. It was shown that transplantation of allogeneic mesenchymal stem cells (2 million cells per 1 kg body weight) immediately after ligation of the left anterior descending coronary artery between the middle and upper thirds led to neovascularization and capillarization of the ischemic myocardium.

[Preclinical study of AV0012 early stage inhibitor of hepatitis C virus infection: I. In vitro ADME and pharmacokinetics].

In vitro immunohistochemical investigations on the human hepatoma cell line (Huh7) infected with hepatitis C virus (HCV) strain JFH-1 showed that AV0012 compound blocks the early stages of viral infection. AV0012 also blocked viral infection spread in tissue culture through the secreted virus and through tight cell-to-cell contact. AV0012 is a specific inhibitor of HCV but not of related pestivirus, flaviviruses and other RNA-containing viruses such as bovine diarrhea (BVDV), Venezuelan equine encephalitis (strain TC-83), dengue type 2 (New Guinea), yellow fever (strain 17D), west Nile fever, parainfluenza (type 3) virus, RSV (strain A2), and Rhinovirus (type 2 strain HGP). It is established that human serum does not significantly affect the antiviral activity of AV0012 in vitro. The drug combination studies with AV0012 and interferon alpha 2a in vitro showed that the two inhibitors act additively, which makes possible the use of this combination in clinical tests. AV0012 is highly soluble and stable in aqueous solutions and murine blood plasma, has limited metabolic stability, low binding to human plasma proteins, high permeability through biological membranes, and only interacts with isoenzymes 2D6 and 3A4 of human cytochrome P450. In animal pharmacokinetic studies, AV0012 was rapidly absorbed into the blood stream upon oral administration, showed sufficiently long half-elimination times, and had high oral bioavailability that reached 92% in monkeys. Further preclinical development of AV0012 is in progress.

Physiological parameters of Macaca fascicularis immunized with anti-rubella vaccine with germanium-based adjuvants.

Clinical status, hematological and biochemical parameters, and allergenic activity of organogermanium compounds used as adjuvants in complex with preparation from Orlov rubella virus vaccine strain and reference commercial anti-rubella vaccine based on Wistar RA 27/3 strain were studied on Macaca fascilcularis of both genders. Physiological parameters of monkeys immunized with the Russian and foreign rubella virus vaccine strains with and without adjuvants did not differ. The adjuvants were inessential for the safety of vaccines (absence of toxicity, reactogenic activity, or allergenic activity) in preclinical studies on lower primates.

Cellular immunity standard values in Macaca fascicularis.

Cellular immunity of clinically healthy Macaca fascicularis was studied by fl ow cytometry with monoclonal antibodies. Parameters of cellular immunity in Macaca fascicularis and Macaca rhesus virtually coincided and were maximally close to those in humans.

[Preclinical study of safety of the new pharmacological substance AV0012 to treat hepatitis C].

Pharmacological safety of a new type of HCV inhibitor, AV0012, was studied including acute, subchronic and chronic toxicity in mice, rats and monkeys. Genotoxicity was assessed using the Ames test and the chromosomal aberrations assay in the bone marrow cells of mice. It is established that AV0012 has low toxicity in SHK line mice, Wistar line rats, and monkey of Rhesus macaques species. Results obtained in the study of genetic toxicity showed that AV0012 exhibits no mutagenic activity. Data on general toxicity and mutagenicity discussed in this paper, together with data on 1 the pharmacological activity, pharmacokinetics, and metabolism published previously, allow us to consider AV0012 as a candidate drug for clinical research phase I.

[Efficiency of cycloferon against slow viral infection caused by SV-40 in monkeys and man].

The latent infection caused by Simian virus (SV-40) defeats monkeys and others animals. Currently there are not the prophylactic and therapeutic measures against this disease. We showed the infringement of immunity of M. mulatta infected by SV-40. The use of the preparation Cyclopheron for the treatment of this infection led to the normalization of the functions of immunity of monkeys and to disappearance of the virus from the organism. We suggested the new method for prophylaxis and treatment of latent SV-40 infection by Cyclopheron, may be used for the correction of the immunity.

Possible aspects of using cultured stem cell of laboratory primates in experimental medicine.

We describe the methods of isolation and culturing of mesenchymal stem cells from 3 monkey species Macaca mulatta, Papio hamadryas, and Macaca fascicularis. Flow cytofluorometry showed that the cells do not express CD34, CD45, and HLA-DR, but most of them (78-98%) express CD90 marker. The cardioprotective effects of cultured mesenchymal stem cells in cardiomyopathy induced by administration of antitumor anthracycline drugs (doxorubicin).

[Cycloferon therapy of cytomegalovirus infection in monkeys].

Cytomegalovirus (CMV) infection is a wide-spread disease throw humans and monkeys, which and associated with various diseases. The development of this infection in human organism is much like that in rhesus macaque, which makes CMV-infected monkeys adequate model for studying and elaborating prophylactic and therapeutic measures against this disease in humans. This article presents data on the efficiency of cycloferon action on animals with the M. mulatta CMV infection. Cycloferon stimulated an increase in the IFN-alpha production and promoted the period of remission in CMV-infected animals.

Blood picture and interferon status of monkeys infected by simian latent viruses.

The blood picture and interferon status of rhesus macaques infected with one or two simian latent viruses do not differ from those of clinically healthy seronegative monkeys.

Effects of low-dose γ-irradiation on the counts of immunocompetent cells in a model experiment on primates.

Cellular immunity was studied by flow cytometry with Becton Dickinson monoclonal antibodies in clinically healthy Macaca mulatta males before and after low-dose exposure to ionizing radiation. It was shown that T and B cells are radiosensitive, B cells being more sensitive, which is seen from a significant drop of their count. Natural killers are radioresistant. The count of immunocompetent cells recovers sooner after single compared to fractionated irradiation in the same summary dose.

Parameters of cellular immunity in primates.

Cellular immunity in clinically healthy Macaca mulatta was studied by flow cytometry using monoclonal antibodies (Becton Dickinson). The immune parameters of monkeys were close to those in humans.

Parameters of the cytokine system functioning in laboratory primates.

The cytokine status (IFN, IL, etc.) of different monkey species (M. mulatta, P. hamadryas, C. aethiops) was studied. The interferon status is determined by the following parameters: IFN content in circulating blood and production of IFN-alpha and IFN-gamma by lymphocytes after appropriate in vitro induction. The interferon status of monkeys is similar to that of humans. The capacity to produce IFN reduces with age. It was found that genes of virtually all studied cytokines are expressed in blood cells and hence, in immune system cells.

[Comparative immunophenotypic characterization of human and monkey permanent lymphoid culture cells].

The aim of the study was to define the comparative immunophenotypic characteristics ofwidely spread lymphoid cell cultures, derived from Burkett's lymphoma named as Raji and P3HR-1 in comparison with analogous monkey cultures. It has been shown that P3HR-1 culture consists of similar type cells - activated B-lymphocytes CD23 with k phenotype, which demonstrates its monoclonality. Raji culture includes cells with markers of immature B-lymphocytes CD10 and CD24, as well as elements expressing CD10 antigens. T-cell markers were found in none of the cultures. In contrast to human cells, monkey lymphoid culture expressed both B- and T-cell markers. Moreover, in one of them, obtained from a green monkey, T-cells of suppressor type (CD8) prevailed. The immunophenotypic characteristics of primate lymphoid cell cultures, revealed by the study, are of great importance for their proper application to medical and biological studies.

[Immune and interferon status of primates].

The authors of the article have first determined standards of interferon (IFN) status of healthy primates (M. mullatta) belonging to different age groups, such as serum IFN, spontaneous IFN production, IFN-a and IFN-y production. They showed that old healthy primates have low ability of IFN-a and IFN-y production and high serum IFN level. The parameters of IFN status were compared to the number of B- and T-lymphocytes and their subpopulations; qualitative evaluation of protective properties of young and old healthy primates' immunity was carried out.

[The virogenic status of cultured continuous simian lymphoid cells and their immunophenotypical characteristics].

Immunophenotyping of cultured continuous simian lymphoid cultures using a panel containing monoclonal antibodies to human B- and T-cell antigens has been carried out, by employing enzyme immunoassay and flow cytofluorometry. The test cultures showed a wide variety of cells containing B- and T-cell antigens with their varying expression. The cultures were also found to comprise lymphoblasts simultaneously containing B- and T-cell markers. Simian lymphotropic viruses, such as EBV-like and STLV-1 retrovirus, detected apart or simultaneously, have been verified by polymerase chain reaction. Whether there is a possible relationship between the type of cells in the culture and the type of their replicating virus(es) is discussed in the paper.

Immunophenotypical characteristics of permanent cultures of lymphoid cells from Papio hamadryas and Macaca arctoides.

Immunophenotypical characteristics of primate cells were studied by enzyme immunoassay and flow cytofluorometry using a panel of monoclonal antibodies to human B- and T-lymphocyte antigens. Specific features of immunophenotype of cultured cells were detected. Simian lymphoid cultures consist of a mixture of B- and T-cells with mosaic antigenic structure expressing markers of B and T cell specificity.