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Sofia, Bulgaria

Antonov B.,Sofia University | Bochev I.,SAGBAL D r Shterev | Mourdjeva M.,Bulgarian Academy of Science | Kinov P.,Sofia University | And 3 more authors.
Biotechnology and Biotechnological Equipment | Year: 2013

The aim of this study was to investigate the proliferation and osteogenic differentiation of mesenchymal stem cells in contact with porous coated titanium implant. Human mesenchymal stem cells (BM-MSCs) were obtained from bone marrow aspirate from the femoral canal during elective hip replacement. The MSCs were isolated and cultured. The resulting cells were seeded on porous coated titanium plates obtained from prosthesis blanks that had all the characteristics of the final product. The same cells were grown on classic plastic polystyrene plates as a control specimens. The proliferation and osteogenic differentiation of the isolated and cultured mesenchymal stem cells were examined. Our results show that under the same conditions there were no significant differences between the study and control groups. Titanium implants with porous coated surface provide favorable conditions for the proliferation and differentiation of bone marrow stem cells and did not inhibit their development. In conclusion, it may be possible to advance this methodology to stimulate healing of bone defects and particularly massive osteolysis in the revision arthroplasty setting. MSCs may provide an alternative to the use of autologous and allogenic bone-grafts in orthopedic surgery. © Biotechnol. & Biotechnol. Source

Kyurkchiev D.,Medical University-Sofia | Naydenov E.,Medical University-Sofia | Tumangelova-Yuzeir K.,Medical University-Sofia | Ivanova-Todorova E.,Medical University-Sofia | And 7 more authors.
Cellular and Molecular Neurobiology | Year: 2014

Glioblastoma multiforme (GBM) is the most common and malignant tumor in the central nervous system. One of the contemporary hypotheses postulates that its pathogenesis is associated with the cancer stem cells (CSCs) which originate from mutations in the normal neural stem cells residing in their specific "niches." Simultaneously with its aggressive development the tumor suppresses the local immune system by different secreted and/or cell expressed factors. Progesterone-induced blocking factor (PIBF) is an immunomodulatory protein with known role in the regulation of the immune response in the reproductive system. Expression of PIBF has been described in some tumors as one of the factors suppressing the anti-tumor immunity. The aim of the present study was to check for the expression of PIBF from cells isolated from six GBMs. To characterize the cultured cells and to study the PIBF expression confocal microscopy, flow cytometry, ELISA, and real-time PCR were used. The results obtained showed expression of markers typical for cancer CSCs and secretion of interleukin 6 by the GBM-derived cultured cells. The results convincingly prove that PIBF is intracellularly expressed by the cultured cells from the all six GBM samples, and this fact is confirmed by three different methods - flow cytometry, confocal microscopy, and real-time PCR. This paper reports for the first time the expression of PIBF by GBM-derived cells cultured in vitro and reveals a new aspect of the immunosuppressive mechanism used by GBM in escaping the immune control. © 2014 Springer Science+Business Media New York. Source

Bochev I.,Ob Gyn Hospital Dr. Shterev | Belemezova K.,Tissue bank Bulgen | Shterev A.,Ob Gyn Hospital Dr. Shterev | Kyurkchiev S.,Tissue bank Bulgen | Kyurkchiev S.,Institute of Reproductive Health
Journal of Assisted Reproduction and Genetics | Year: 2016

Purpose: Along with comparative investigation of the decidualization potential and IL-6 secretion by fresh and frozen ESCs, we also aimed to evaluate the effectiveness of co-culture systems based on fresh or frozen ESCs in terms of clinical pregnancy rates. Methods: Outcome analysis of a total of 215 IVF cycles with co-culture with fresh or frozen ESCs was performed. Endometrial tissue was obtained from 17 healthy donors. Concentrations of secreted prolactin, IGFBP-1, and IL-6 in conditioned media from cultured fresh and frozen ESCs (decidualized or not) were measured using ELISA or ECLIA. Results: Embryo co-culture with frozen ESCs resulted in a much lower pregnancy rate compared to the alternative system using fresh ESCs. Furthermore, cultivated frozen ESCs showed considerably decreased release of prolactin, IGFBP-1, and IL-6 compared to fresh ESCs, indicating that cryopreservation negatively affects their decidualization potential and cytokine production. Conclusions: Altogether, this data illustrates the need for optimization and improvement of the existing autologous endometrial co-culture systems. © 2016 Springer Science+Business Media New York Source

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