Identification of mesenchymal stem cell marker STRO-1 in oral reactive lesions by immunofluorescence method

Statement of the Problem: Stem cells are considered as new implement for tissue regeneration. Several niches in adult human body are colonized by multipotent stem cells but access to these potential reservoirs is often limited. Although human dental pulp stem cells isolated from healthy teeth have been extensively characterized, it is still unknown whether stem cells also exist in reactive lesions of oral cavity such as pyogenic granuloma and peripheral ossifying fibroma which are deliberated as inflammatory proliferation of different cell families

Purpose: The aim of this study was to explore for clues to see whether pyogenic granuloma or peripheral ossifying fibroma contain dental mesenchymal stem cell [DMSC]

Materials and Method: Four pyogenic granuloma and four peripheral ossifying fibroma specimens were collected by excisional biopsy and preserved in PBS-EDTA at -86 [degree]C. Then we cut them in 5?m diameter using Cryostat. Having been rinsed with PBS, the samples were stained with a primary mouse anti-human STRO-1 monoclonal IgM antibody. Afterward, a secondary goat anti-mouse IgM-FITC antibody was applied to detect STRO-1+ cells as probable stem cells by immunofluorescence technique

Results: Immunofluorescence microscopy revealed presence of STRO-1+ cells in these lesions, particularly localized on perivascular zone. The negative control group was not glowing

Conclusion: Based on these results, it was found that reactive lesions of pyogenic granuloma and peripheral ossifying fibroma have STRO-1 positive cells, which raises the possibility that these cells may be DMSCs

Absence of Correlation between Changes in the Number of Endothelial Progenitor Cell Subsets

BACKGROUND AND OBJECTIVES: Previously, various methodologies were used to enumerate the endothelial progenitor cells (EPCs). We now know that these methodologies enumerate at least three different EPC subsets: circulating angiogenic cells (CACs), colony-forming unit endothelial cells (CFU-ECs), and endothelial colony-forming cells (ECFCs). It is not clear whether there is a correlation between changes in the number of these subsets. The aim of the current study is to find an answer to this question. MATERIALS AND METHODS: The number of all EPC subsets was quantified in the peripheral blood of nine pregnant women in their first and third trimesters of pregnancy. We enumerated 14 cell populations by quantitative flow-cytometry using various combinations of the markers, CD34, CD133, CD309, and CD45, to cover most of the reported phenotypes of CACs and ECFCs. Culturing technique was used to enumerate the CFU-ECs. Changes in the number of cells were calculated by subtracting the number of cells in the first trimester peripheral blood from the number of cells in the third trimester peripheral blood, and correlations between these changes were analyzed. RESULTS: The number of CFU-ECs did not correlate with the number of ECFCs and CACs. Also, CACs and ECFCs showed independent behaviors. However, the number of CACs showed a strong correlation with the number of CD133+CD309+ cells (p=0.001) and a moderate correlation with the number of CD34+CD309+ cells (p=0.042). Also, the number of ECFCs was correlated with the number of CD309+CD45- cells (p=0.029) and CD34+CD45- cells (p=0.03). CONCLUSION: Our study showed that the three commonly used methods for quantifying EPC subsets represent different cells with independent behaviors. Also, any study that measured the number of EPCs using the flow cytometry method with a marker combination that lacks CD309 may be inaccurate.

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

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