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Hori Ghaneialvar Leila Soltani Hamid Reza Rahmani Abbas Sahebghadam Lotfi Masoud Soleimani 《Indian journal of clinical biochemistry : IJCB》2018,33(1):46-52
Mesenchymal stem cells are multipotent cells capable of replicating as undifferentiated cells, and have the potential of differentiating into mesenchymal tissue lineages such as osteocytes, adipocytes and chondrocytes. Such lineages can then be used in cell therapy. The aim of present study was to characterize bone marrow derived mesenchymal stem cells in four different species, including: sheep, goat, human and mouse. Human bone-marrow mesenchymal stem cells were purchased, those of sheep and goat were isolated from fetal bone marrow, and those of mouse were collected by washing bone cavity of femur and tibia with DMEM/F12. Using flow-cytometry, they were characterized by CD surface antigens. Furthermore, cells of third passage were examined for their osteogenic and adipogenic differentiation potential by oil red and alizarin red staining respectively. According to the results, CD markers studied in the four groups of mesenchymal stem cells showed a different expression. Goat and sheep expressed CD44 and CD166, and weakly expressed CD34, CD45, CD105 and CD90. Similarly, human and mouse mesenchymal cells expressed CD44, CD166, CD105 and CD90 whereas the expression of CD34 and CD45 was negative. In conclusion, although all mesenchymal stem cells display plastic adherence and tri-lineage differentiation, not all express the same panel of surface antigens described for human mesenchymal stem cells. Additional panel of CD markers are necessary to characterize regenerative potential and possible application of these stem cells in regenerative medicine and implantology. 相似文献
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Kathe Callahan Leila Sadeghi 《美中教育评论》2014,(10):728-736
In July 2009, the Obama administration lauched its $4.35 billion Race to the Top (RTT) Fund, providing states with competitive grants in an effort to reform education. One of the main conditions of this program was to award educational innovation. With this in mind, states enacted new legislation in the hopes of attracting more funding for their proposed programs. Although there were many levels of reform targeted by the RTT, of significance to this research is the emphasis placed on improving teacher effectiveness and measuring teacher performance via evaluation systems. The Teacher Effectiveness and Accountability for the Children of New Jersey (TEACHNJ) Act was adopted by the New Jersey legislature in August 2012 with the intent to raise student achievement by improving the quality of instruction. This research explores the impact the TEACHNJ Act has on teacher evaluations and professional development. A survey was administered to 1,235 public school teachers in New Jersey to ascertain teacher perceptions of the: (a) evaluation system in their school; (b) level of communication between teachers and administrators; and (c) availability, frequency, and effectiveness of professional development opportunities. The response rate was 21%. We found that formal evaluations are conducted infrequently with a varying degree of accuracy and impact. Nearly half of the teachers indicated that formal evaluations did not lead to improvements in their classroom. A majority of teachers questioned the administrative value of formal teacher evaluations, in particular the rewards and sanctions associated with the outcome of evaluations and a concem that poor performers were not sanctioned nor were effective teachers rewarded. We found that teachers perceive the greatest value to professional development, which is derived from peer mentoring and observations. We also found that professional development is the most effective when it is offered onsite, embedded in the classroom, continuous, and sustained over ti 相似文献