Bone marrow fibroblast colony-forming units (CFU-F) were evaluated in cats experimentally infected with different isolates of FeLV. Cats infected with the Kawakami-Theilen isolate of FeLV (FeLV-KT) had progressive decrease in the number of CFU-F at 2, 4, and 6 weeks after infection. The number of CFU-F in FeLV-KT-infected cats ranged from 38 to 70% of the preinoculation CFU-F value. Of 3 cats with FeLV-KT-induced suppression of CFU-F, 2 developed fatal nonregenerative anemia. Cats infected with the Rickard isolate of FeLV (FeLV-R) had more moderate decrease in the number of CFU-F at 2, 4, and 6 weeks after infection. The number of CFU-F in FeLV-R-infected cats ranged from 62 to 82% of the preinoculation CFU-F value. The FeLV-R-infected cats did not become anemic.

Mesenchymal stem cells (MSCs) have ability to differentiate into multi-lineage cells, which confer a great promise for regenerative medicine to the cells. The aim of this study was to establish a method for isolation and characterization of adipose tissue-derived MSC (pAD-MSC) and bone marrow-derived MSC (pBM-MSC) in pigs. Isolated cells from all tissues were positive for CD29, CD44, CD90 and CD105, but negative for hematopoietic stem cell associated markers, CD45. In addition, the cells expressed the transcription factors, such as Oct4, Sox2, and Nanog by RT-PCR. pAD-MSC and pBM-MSC at early passage successfully differentiated into chondrocytes, osteocytes and adipocytes. Collectively, pig AD-MSC and BM-MSC with multipotency were optimized in our study.

Bone marrow derived mesenchymal stem cells (MSCs) can be used to repair articular cartilage defects, these cells should be properly stimulated so that they could differentiate morphologically and hold cellular synthetic features closer to maturely differentiated chondrocytes. It is well known that tissue specific environment plays an important role in cell fate determination. Once improved isolation, proliferation and differentiation protocols have been developed, the likelihood of spontaneous differentiation of MSCs into divergent lineages will be reduced, thus increasing their value for cartilage repair. The purpose of this study was to improve chondrogenic differentiation of equine MSCs using coculture with mature equine articular chondrocytes (ACs), along with the determination of the effect of adding transforming growth factor (TGF) beta1 in the pellet culture system. Following confirmation of multilineage (adipogenic, osteogenic and chondrogenic) differentiation, isolated MSCs, ACs and coculture of both cell types were transferred into pellet culture system in a DMEM-based medium supplemented with or without TGFbetal. Chondrogenic differentiation was evaluated histologically and the relative mRNA expressions of collagen type 1 alpha1 (COL1A1), collagen type 2 alpha1 (COL2A1), aggrecan (ACAN) and SRY-box 9 (SOX9) were estimated by quantitative RT-PCR. Cocultured cells showed diffuse distribution of extracellular matrix (ECM), whereas in chondrocyte pellets it was more localized to central regions. Expression of COL2A1, ACAN and SOX9 genes were higher in cocultured pellets when compared to MSCs and ACs-composed pellets. Addition of TGFbeta1 in chondrogenic differentiating medium did not consistently amplify expression of the above mentioned genes. Differentiation of equine MSCs was enhanced by coculturing in association with mature ACs, improving expression of cartilage-specific genes and producing a more homogeneous production of ECM within the newly formed cocultured cartilage. The use of the coculture system could possibly enhance the capacity of MSC-derived chondrocytes to build up stable articular cartilage-like constructs, which could play an important role in articular cartilage repair and regeneration.

Bovine bone marrow mesenchymal stem cells (MSCs) cultured in condensate culture, spontaneous and independent for any external biostimulants, undergo chondrogenic differentiation. In the present study, the bovine MSC chondrogenesis pathway was studied by analyzing stage-specific gene expression using quantitative 'Real Time' reverse transcriptase polymerase chain reaction (qRT-PCR). Results showed that bovine MSCs underwent complete chondrogenesis; the initial stage was characterized by expression of sox 9 messenger ribonucleic acid (mRNA), followed by high transcription of chondrocyte specific genes, collagen type II and IX, biglycan and cartilage oligomeric matrix protein, and the final prehypertrophic and/or hypertrophic stage was distinguished by increased expression of collagen type X. From day 7 to day 14 of differentiation increased mRNA expression of the transforming growth factors beta1 and beta2, basic fibroblast growth factor (FGF 2), bone morphogenic protein 6 (BMP 6), insulin-like growth factors 1, parathyroid hormone related peptide and indian hedgehog (Ihh) were detected. These results suggest that these well know chondrogenic growth factors may play a role in bovine chondrogenesis in autocrine and/or paracrine manner. On day 21 of the culture, FGF 2, BMP 6 and Ihh were highly expressed, compared to cells cultured in monolayer manner, which suggests a possible function in maintaining the terminal stage of differentiation. This data extends our knowledge about the unusual species-specific bovine MSC chondrogenesis, allowing us to define the phenotype of the differentiated cells. Furthermore, this study contributes to our in understanding of known chondrogenic-growth factors in autocrine and/or paracrine manner playing a role in the spontaneous differentiation.

Influence of potassium orotate on hematological, immunomorphological indexes and and marrowy myelopoiesis of broiler chickens in the process of oral associated immunization against infectious bronchitis and poultry Newcastle disease was investigated in the conditions of the Republic of Belarus. There were studied 60 broiler chickens divided into 3 groups: one control group and two experimental ones. Research results established that potassium orotate application in combination with associated poultry immunization against infectious bronchitis and Newcastle disease increased the number of leucocytes and the volume of adenoid tissue as well as raised the lymphocytes density in thymus and bursa of Fabricius. In the bone marrow aspirates in 7 days after immunization in the control group there was stated the increasing of basophilic myelocytes number in comparison with the second experimental group. In 14 days in the control group there was noted the increasing of a total number of basophiles. In 21 days after immunization there were stated no considerable changes in the composition of basophil cells in the experimental groups. Research results showed that potassium orotate intensively stimulated the development of plasmocytic reaction in the conditions of multipartial immunization

Morphological and structural changes in bone marrow of piglets which were immunized with produced in the Republic of Belarus SPS vaccine (against salmonellosis (Salmonella), pasteurellosis (Pasteurella) and streptococcus) in combination with immunostimulants and without them were analyzed in the conditions of the Republic of Belarus. Piglets of the first group were vaccinated against salmonellosis, pasteurellosis and streptoccocusis by SPS vaccine. Piglets of the second group were vaccinated by SPS vaccine with vitamin C. Piglets of the third group were vaccinated by SPS vaccine with immunotstimulant sodium thiosulphate. The fourth (control) group of animals was administrated with normal saline. Animals were immunized twice, intramuscularly with 7 day interval in dose of 4 ml (primary), and 5 ml (secondary). Vitamin С was administrated in dose of 0,05g per head. Sodium thiosulfate was administrated in combination with the vaccine in 30% concentration. Alongside with myelogram there were derived formulas of different cell groups of bone marrow: leucoerythroblastic index; intramedullary index of neutrophil maturity; intramedullary index of eosinophile maturity. Detailed myelogram of piglets on the 14-th day after the second immunization was presented. Research results showed that in all groups of vaccinated animals there was noted the activation of myeloblastic hematogenesis and decreasing of erythropoeisis. Piglet immunization was accompanied by strengthening of myeloblastic hematogenesis, increased number of lymphocytes and plasma cells in bone marrow

In the conditions of the Republic of Belarus there was realized a morphological study of bone marrow aspirates at different terms chicken of immunization against Gumboro disease which made it possible to analyze the state of immune system for the objective evaluation of immunological status. Research results showed that chicken immunization with a national liquid chick embryo viral vaccine produced on the basis of KMIehV-13 strain against Gumboro disease (infectious bursal disease) promoted the development of immunomorphological remodeling of bone marrow. Application of immunostimulants Alveozan and Nukleovit for poultry vaccination caused more expressed changes revealing in statistically reliable increasing of total number of myeloblastic cells in the majority of cases by means of increasing of immature cells, and then mature cells of granulocytic series, as well as quantity of lymphocytes and plasmacytes