Characterization of stem cells from the pulp of unerupted third molar tooth.

Context: Dental pulp stem cells (DPSCs) are the most diagnosed type of stem cells isolated from dental tissues. Previous studies demonstrate that tissues in earlier stages of development could be better stem cell resources for tissue engineering. Aims: In this study, aiming at finding younger stem cell resources, we chose the pulp of human unerupted third molar teeth when the crown was completely formed and the roots had not begun their development, Nolla's 6 th developmental stage (N6 th ). Materials and Methods: Surgical removal of the third molar was performed by aseptic technique with minimal trauma. The tissues were digested enzymatically and the resulted single cells were cultured. Immunophenotypic characterization of the cells was done via immunocytochemistry, immunofluorescence, and flow cytometry assays. Adipogenic and osteogenic differentiation potential of these cells was examined and confirmed by histochemical staining and reverse transcription-polymerase chain reaction analysis. Statistical Analysis Used: This study is descriptive. Results: N6 th -unerupted dental pulp cultured cells expressed DPSC markers: Vimentin, CD73, CD90, CD105, CD166, CD44, CD146, and STRO-1, but did not express hematopoietic cell markers: CD14, CD34, CD45, HLA-DR and were also negative for dentin sialoprotein negative showing an undifferentiated preodontogenic state. Adipocytes differentiated from N6 th -DPSCs were positively stained with Oil-Red-O and expressed both early and late adipocyte specific genes. Formation of Alizarin-red positive condensed calcium-phosphate nodules accompanied by strong expression of two osteogenic mRNAs, exhibited osteogenic differentiation. Conclusion: Based on the results of this study, we suggest that N6 th -DMSCs are a viable choice for cryo-banking and future usage in regenerative therapies; however, more investigations are necessary before clinical application can commence.

effect of human platelet-rich plasma on adipose-derived stem cell proliferation and osteogenic differentiation

The cultured mesenchymal stem cells [MSC] have been used in many clinical trials; however, there are still some concerns about the cultural conditions. One concern is related to the use of FBS as a widely used xenogeneic supplement in the culture system. Human platelet-rich plasma [hPRP] is a candidate replacement for FBS. In this study, the effect of hPRP on MSC proliferation and osteogenic differentiation has been evaluated. Human adipose-derived stem cells [hADSC] were expanded. Cells from the third passage were characterized by flow cytometric analysis and used for in vitro experiments. Resazurin and alizarin red stains were used for cell proliferation and osteogenic differentiation assays, respectively. Treatment with hPRP resulted in a statistically significant increase in cell proliferation compare to the negative control group [P<0.001]. Cell proliferation in the 15% hPRP group was also significantly higher than that in the 10% hPRP group [P<0.05]. Additionally, it caused less osteogenic differentiation of the hADSC compared to the FBS [P<0.001], but in comparison to negative control, it caused acceptable mineralization [P<0.001]. These findings indicate that hPRP not only improves the proliferation but also it can be a suitable substitution in osteogenic differentiation for clinical purposes. However, the clinical application value of hPRP still needs more investigation

Medical podcasting in Iran; pilot, implementation and attitude evaluation

Podcasting has become a popular means of transferring knowledge in higher education through making lecture contents available to students at their convenience. Accessing courses on media players provides students with enhanced learning opportunities. Development of teaching methods able to cope with ever-changing nature of medicine is crucial to train the millennium students. Pharmacology education in Tehran University of Medical Sciences has been based on lectures so far; our aim was to implement a pilot study to evaluate the advantages and disadvantages of offering the course contents as podcasts as well as evaluating whether such program can be feasible in our educational program. 46% of students downloaded the podcast according to our download center. 48% favored usage of both internet and DVD-ROM concurrently. Overall 96% of students perceived that podcasting had a positive impact on their learning in pharmacology course. Our results indicate that most of attendants proposed the positive yields of podcasting despite low usage of it, mainly as a pre-class preparing tool

Colony forming unit endothelial cells do not exhibit telomerase alternative splicing variants and activity

Endothelial progenitor colony forming unit-endothelial cells [CFU-EC] were first believed to be the progenitors of endothelial cells, named endothelial progenitor cells. Further studies revealed that they are monocytes regulating vasculogenesis. The main hindrance of these cells for therapeutic purposes is their low frequency and limited replicative potentials. This study was undertaken to determine telomerase activity and alternative splicing variants in CFU-EC as a potential cause of limited replicative capacity in these cells. CFU-EC were isolated from peripheral blood using a standard cell culture assay. Colonies were detached mechanically and alternative splicing variant mRNA were evaluated using real-time PCR. Telomerase enzyme activity was assessed using telomerase repeat amplification protocol. The same procedures were done on the cancer cell line Calu6 as the positive control. The cultured peripheral blood mononuclear cells formed colonies with spindle-shaped monocytic cells sprouted from the clusters. These morphological characteristics fulfill the definition of CFU-EC. Telomere length amplification protocol assay revealed no telomerase activity and real-time PCR showed no expression of telomerase enzyme mRNA in CFU-EC. Both parameters were significantly higher in the cancer cell line Calu6 taken as the positive control. The absence of telomerase activity in the CFU-EC is a result of pre-transcriptional regulation of gene expression rather than other mechanisms for controlling telomerase activity such as post-transcriptional modifications. This finding can explain the limited proliferative activity of CFU-EC cells. We propose that absence of telomerase activity in CFU-EC can be attributable to their more mature monocytic nature that needs further investigations

Congenital sternal foramen in a stillborn Holstein calf

Congenital sternal foramen is an anomaly whose occurrence is rare in human but is especially unusual in animals. This defect was formed when fusion of multiple ossification centers was incomplete. It may be associated with other lesions in body organs especially cardiac anomalies. In the present study, we report a very rare case of congenital sternal foramen in a Holstein calf. The oval defect was like a gunshot wound and located at the lower third of the sternum. Apparently, the rest of skeleton system seems normal. The awareness of the anomaly is important for better diagnosis and treatment of diseases.

Hydatid cyst of ovary: a case report

Echinococcus granulosus is considered the major cause of human hydatid cysts. Usually the duration of cyst formation is 10-20 years. This period shortens significantly upon rupture of a primary cyst. The literature describes low incidence of primary involvement of ovary as a site of hydatid cyst formation. Our case is the first report on ovarian hydatid cyst in Iran. A 60-year-old woman was presented with abdominal pain in the left lower quadrant area. Paraclinical data were suggestive of neoplasia and preoperative diagnosis was ovarian tumor. During laparotomy, multiple cysts resembling hydatid cysts were observed in the left ovary. Pathological examination confirmed the diagnosis of hydatid cyst. Although there is a small possibility of secondary ovarian echinococcal disease, it is more probable for this case to be primary infection, as the patient had developed ovarian hydatid cysts 15 years after hepatic involvement and recurrence after 30 months is very uncommon