Effect of dental materials calcium hydroxide-containing cement, mineral trioxide aggregate, and enamel matrix derivative on proliferation and differentiation of human tooth germ stem cells

Introduction

Biocompatibility of pulp capping materials is important for successful use in dentistry. These materials should be nontoxic and permissive for proliferation and induction of odontogenic differentiation of pulp cells. The aim of our study was to evaluate the effects of enamel matrix derivative (EMD), mineral trioxide aggregate (MTA), and calcium hydroxide-containing cement (DYCAL) on proliferation and odontogenic differentiation of human tooth germ stem cells (hTGSCs) in which cells belonging to both pulp tissue and dental follicle exist.

Methods

The 96-well plates, 24-well plates, and special chamber slides were coated with biomaterials for cell proliferation, differentiation, and scanning electron microscopy analysis. Odontogenic differentiation of hTGSCs was evaluated by analyzing mRNA expression of dentin sialophosphoprotein (DSPP) by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase activity, and visualization of calcium depositions by von Kossa staining.

Results

Our results demonstrate that EMD is the best material in terms of inducing differentiation and proliferation of hTGSCs. DYCAL was found to be toxic to hTGSCs; however, EMD-coated DYCAL showed less toxicity. EMD-coated MTA was not efficient at inducing proliferation and differentiation.

Conclusions

Pulp capping materials come in direct contact with dental pulp cells; thus, they require comprehensive evaluation of interactions between cells and biomaterials. Therefore, we cultured hTGSCs, capable of odontogenic differentiation, on pulp capping materials directly. Our results suggest that combination of capping materials with EMD would increase the quality of capping by increasing biocompatibility of capping materials.     

EMD or subepithelial connective tissue graft for the treatment of single gingival recessions: a pilot study

Alkan EA, Parlar A. EMD or subepithelial connective tissue graft for the treatment of single gingival recessions: a pilot study. J Periodont Res 2011; 46: 637–642. © 2011 John Wiley & Sons A/S Background and Objective: The combination of EMD with root‐coverage procedures has been shown to promote periodontal regeneration on the exposed root surface. The aim of this randomized clinical study was to compare the efficacy of EMD with connective tissue graft (CTG) for the treatment of Miller Class I and Class II single recessions in a split‐mouth design. Material and methods: The study included 12 systemically healthy patients, each with two single bilateral gingival recession defects (24 recessions). One recession defect in each patient was treated with the coronally advanced flap (CAF) + EMD procedure and the other recession defect was treated with the CTG + EMD procedure, in a split‐mouth study design. The parameters recession depth (RD), recession width, percentage of root coverage, height of keratinized tissue (HKT), gingival thickness, probing depth and clinical attachment level (CAL) were recorded at baseline. All parameters, except for gingival thickness, were remeasured at 6 and 12 mo. Results: The mean percentage root coverage at the final evaluation was 92 ± 14% for the CAF + EMD group and 89 ± 14% for the CAF + CTG group. Both treatments resulted in statistically significant (p < 0.05) decreases in RD and recession width, and increases in HKT, at 6 and 12 mo. There was also a significant decrease in the probing depth and a significant gain in the CAL for both groups. The probing depth was statistically higher in the CAF + CTG group than in the CAF + EMD group at 6 mo (p < 0.05), while the CAL was statistically lower in the CAF + EMD group than in the CAF + CTG group at 6 and 12 mo (p < 0.05). Conclusion: The present study demonstrated that both CAF + EMD and CAF + CTG procedures were similarly successful in treating Miller Class I and Class II single gingival recession defects.     

Effect of Emdogain enamel matrix derivative and BMP-2 on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells

The objective of this study was to evaluate the effect of Emdogain (Enamel Matrix Derivative, EMD) and Bone Morphogenetic Protein-2 (BMP-2), either solely or in combination, on the gene expression and mineralized nodule formation of alveolar bone proper-derived stem/progenitor cells.Stem/progenitor cells were isolated from human alveolar bone proper, magnetically sorted using STRO-1 antibodies, characterized flowcytometrically for their surface markers' expression, and examined for colony formation and multilineage differentiation potential. Subsequently, cells were treated over three weeks with 100 μg/ml Emdogain (EMD-Group), or 100 ng/ml BMP-2 (BMP-Group), or a combination of 100 ng/ml BMP-2 and 100 μg/ml Emdogain (BMP/EMD-Group). Unstimulated stem/progenitor cells (MACS⁺-Group) and osteoblasts (OB-Group) served as controls. Osteogenic gene expression was analyzed using RTq-PCR after 1, 2 and 3 weeks (N = 3/group). Mineralized nodule formation was evaluated by Alizarin-Red staining.BMP and EMD up-regulated the osteogenic gene expression. The BMP Group showed significantly higher expression of Collagen-I, III, and V, Alkaline phosphatase and Osteonectin compared to MACS⁺- and OB-Group (p < 0.05; Two-way ANOVA/Bonferroni) with no mineralized nodule formation.Under in-vitro conditions, Emdogain and BMP-2 up-regulate the osteogenic gene expression of stem/progenitor cells. The combination of BMP-2 and Emdogain showed no additive effect and would not be recommended for a combined clinical stimulation.     

癫痫及癫痫性精神障碍患者的护理干预

目的：探讨癫痫及癫痫性精神障碍患者的护理干预效果。方法对22例癫痫及癫痫性精神障碍患者在药物治疗同时予以有针对性的护理干预，观察患者的病情变化。结果本组患者均获得临床治愈或好转出院。结论癫痫及癫痫性精神障碍患者的治疗及护理干预是一个持续的过程，良好的护理干预对患者的康复具有重要作用。     

Section Review: Cardiovascular & Renal: Calcium sensitisers and heart failure

To date, the use of positive inotropic agents for the treatment of heart failure has not been a success. Not only have these drugs had little documentable beneficial effect on survival, but in some instances, most notably with the phosphodiesterase inhibitors, they have-caused an unacceptable increase in early mortality due to arrhythmias [1]. This has led to a body of opinion in some quarters that positive inotropic therapy for heart failure is a doomed approach and that all efforts should be concentrated on preventing or reversing atheroma, enhancing blood flow to the myocardium and dealing with the effects of secondary compensatory mechanisms. Although everyone agrees that prevention is better than cure, it seems inevitable that there will always be substantial numbers of patients with heart failure of various degrees of severity. Thus, it is important to be very sure of the facts before abandoning any hope of pharmacological contractile support for these patients. This article briefly reviews current evidence on the potential utility of calcium sensitisers.     

The developing trend of monoclonal antibodies in the treatment of colorectal cancer

Monoclonal antibodies (mAbs) against growth factors, receptors and tumor-specific/tumor-selective antigens represent a rapidly growing class of pharmaceutical agents which are poised to make a major impact on the treatment of colorectal cancer. mAbs targeting the epidermal growth factor receptor and the vascular endothelial growth factor have already been approved for the treatment of metastatic colorectal cancer. Other antibodies to the same and other molecular targets implicated in tumor growth and metastasis are undergoing intense preclinical and clinical evaluation. In both the neoadjuvant and adjuvant clinical settings, although mAbs are typically administered in combination with established cytotoxic chemotherapy regimens given their synergistic effect, several agents have demonstrated efficacy when given as monotherapy. At the same time, combination therapies with multiple targeted biological agents are actively being investigated. Existing clinical data and recent progress in preclinical and clinical studies of mAbs are reviewed.     

Endotracheal versus intravenous epinephrine during electromechanical dissociation with CPR in dogs

The dose-response curves of epinephrine given either IV or endotracheally (ET) were compared during resuscitation from electromechanical dissociation (EMD). Ten anesthetized dogs were subjected to a two-minute period of electrically induced ventricular fibrillation (VF) followed by defibrillation without CPR to produce EMD. Mechanical CPR was followed by injection of either ET or IV epinephrine. Successful response was defined as a return of pulsatile blood pressure within two minutes of drug administration. Using log-dose increments of epinephrine, experimental trials were repeated in each animal. The IV and ET median effective doses were 14 and 130 micrograms/kg, respectively. When the trials were successful, the time between drug administration and either arterial blood pressure increases or return of spontaneous circulation did not differ significantly for the ET and IV groups. These results show that the dosage for epinephrine delivered ET must be higher than the IV dosage to achieve the same response during CPR.