Material and methods: We conducted literature search from Medline, Scopus and Web of Science on clinical studies related to streptokinase-induced hypotension.
Results: Our search yielded 972 citations. After removal of duplicates, 878 articles were screened for eligibility, of which 856 papers were excluded due to various reasons. Of the remaining 22 articles retrieved with full texts, eight relevant articles were selected for final analysis. Three themes emerged as the proposed mechanisms of streptokinase-induced hypotension, including (i) reduction in total peripheral resistance, (ii) complement activation, and (iii) dismissal of hypotheses involving other intermediaries.
Conclusions: Our findings suggest that the underlying mechanism of streptokinase-induced hypotension lies primarily in the reduction in total peripheral resistance.
BACKGROUND: A cocktail of ascorbic acid, β-glycerophosphate, and dexamethasone has been widely used to induce osteoblast differentiation. However, under certain conditions, β-glycerophosphate and dexamethasone can cause a decrease in cell viability in stem cells.
OBJECTIVES: This study aims to determine the cytotoxic effect and potential of ascorbic acid as the sole inducer of osteoblast differentiation.
METHODS: Cytotoxicity analyses in the presence of 10-500 µg/mL ascorbic acid were performed in both cell types using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The concentrations below the IC50 (i.e., 10-150 µg/mL) were used to determine osteoblast differentiation potential of ascorbic acid using the alkaline phosphatase (ALP) assay, von Kossa staining, and reverse transcription-polymerase chain reaction.
RESULTS: SHEDs and DPSCs proliferated for 21 days, expressed a Mesenchymal Stem Cell (MSC) marker (CD73+), and did not express Hematopoietic Stem Cell (HSC) markers (CD34- and SLAMF1-). SHEDs had a higher range of IC50 values (215-240 µg/mL ascorbic acid), while the IC50 values for DPSCs were 177-211 µg/mL after 24-72 hours. SHEDs treated with 10-100 µg/mL ascorbic acid alone exhibited higher ALP-specific activity and a higher percentage of mineralisation than DPSCs. Both cell types expressed osteoblast markers on day 21, i.e., RUNX2+ and BSP+, in the presence of ascorbic acid.
CONCLUSIONS: SHEDs survive at higher concentrations of ascorbic acid as compared to DPSC. The cytotoxic effect was only exhibited at ≥250 µg/mL ascorbic acid. In addition, SHED exhibited better ALP and mineralization activities, but lower osteoblast marker expression than DPSC in response to ascorbic acid as the sole inducer.