AAV1.NT-3 gene therapy attenuates spontaneous autoimmune peripheral polyneuropathy.

The spontaneous autoimmune peripheral polyneuropathy (SAPP) model in B7-2 knockout non-obese diabetic mice shares clinical and histological features with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Secondary axonal loss is prominent in the progressive phase of this neuropathy. Neurotrophin 3 (NT-3) is an important autocrine factor supporting Schwann cell survival and differentiation and stimulates neurite outgrowth and myelination. The anti-inflammatory and immunomodulatory effects of NT-3 raised considerations of potential efficacy in the SAPP model that could be applicable to CIDP. For this study, scAAV1.tMCK.NT-3 was delivered to the gastrocnemius muscle of 25-week-old SAPP mice. Measurable NT-3 levels were found in the serum at 7-week postgene delivery. The outcome measures included functional, electrophysiological and histological assessments. At week 32, NT-3-treated mice showed increased hind limb grip strength that correlated with improved compound muscle action potential amplitude. Myelinated fiber density was 1.9 times higher in the NT-3-treated group compared with controls and the number of demyelinated axons was significantly lower. The remyelinated nerve fiber population was significantly increased. These improved histopathological parameters from scAAV1.tMCK.NT-3 treatment occurred in the setting of reduced sciatic nerve inflammation. Collectively, these findings suggest a translational application to CIDP.

Human cognitive and neuro-psychiatric bio-markers in the cardiac peri-operative patient.

Some of the complexities of surgical interventions include neurological and psychiatric disturbances. Prompt identification and early treatment of these complications are pivotal in achieving excellent clinical results. Recognizing major adverse events such as stroke, seizure or delirium is usually straight-forward, however the discovery of less frequent or more subtle post-operative changes such as cognitive dysfunction might be delayed due to lack of appropriate diagnostic tools. This review summarizes biological markers that can be utilized as surrogates in evaluating surgery-related neuro-psychiatric disorders.

In vitro comparison of induction capacity and biomineralization ability of mineral trioxide aggregate and a bioceramic root canal sealer.

AIM: To compare the effect of mineral trioxide aggregate (MTA) and iRoot SP, a bioceramic root canal sealer, on the cell viability, hard tissue deposition capacity and odontogenic differentiation of human tooth germ stem cells (hTGSCs). METHODOLOGY: The dental materials MTA, iRoot SP and Dycal were packed into Teflon rings and placed on transwell inserts for toxicity evaluations by the MTS assay on days 3 and 7. Dycal was used as a positive control for the cell viability assay. Teflon rings were cocultured with hTGSCs, followed by the induction of odontogenic differentiation. The odontogenic differentiation of hTGSCs and biomineralization ability of the materials were evaluated by analysing the mRNA expression levels of dentine sialophosphoprotein (DSPP) and collagen type 1A (COL1A) by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase (ALP) activity and visualization of calcium deposits by von Kossa staining. RESULTS: MTA and iRoot SP exhibited no cytotoxicity, but Dycal caused cytotoxicity (P < 0.05) of almost all of the cells after 7 days. MTA significantly stimulated (P < 0.05) the odontogenic differentiation of hTGSCs compared with iRoot SP. MTA and iRoot SP increased (P < 0.05) the mRNA levels of COL1A and DSPP mRNA compared with noninduced hTGSCs, which served as a negative control (NC). iRoot SP, however, significantly decreased (P < 0.05) COL1A and DSPP mRNA expression levels compared with the PC. CONCLUSION: MTA and iRoot SP induced hTGSC differentiation into odontoblast-like cells, but MTA might provide more inductive potential and hard tissue deposition compared with iRoot SP.

Cytotoxicity of 5 endodontic sealers on L929 cell line and human dental pulp cells.

AIM: To investigate the cytotoxicity of five root canal sealers on L929 mouse fibroblasts and primary human dental pulp cells. METHODOLOGY: Cylindrical specimens of AH Plus (Dentsply De Trey GmbH, Konstanz, Germany), RoekoSeal (Coltène Whaledent, Langenau, Germany), EndoREZ (Ultradent Products Inc., South Jordan, UT, USA), Epiphany (Pentron Clinical Technologies, LLCC, Wallingford, CT, USA) and Activ GP (Brasseller Inc., USA, Savannah, GA, USA) were kept at 37 °C in a humidified atmosphere of 5% CO(2) for thrice the length of the setting time given by the manufacturer. Extraction of specimens was performed after setting in cell growth medium for 1, 4 and 7 days. Undiluted, 50% and 25% diluted eluates were incubated with cultured cells for 24 and 72 h. Cytotoxicity was assessed using MTS colorimetric bioassay. Kruskal-Wallis test and post hoc Dunn's multiple comparison test were used to compare the sealers and diluted/undiluted eluates in terms of cell viability (% of control). Friedman test and post hoc Dunn's multiple comparison test were performed to compare extraction periods. Wilcoxon test was utilized in comparing 24- and 72-h readings. RESULTS: Undiluted 1-day eluate of Activ GP was significantly more cytotoxic than all other sealers (P < 0.0001). Undiluted 4- and 7-day eluates of Epiphany and Activ GP were significantly more cytotoxic than the other three sealers (P < 0.0001). Diluted eluates of Activ GP and Epiphany were generally less toxic than the undiluted ones. The cytotoxicity of Epiphany significantly increased as the extraction period increased (P < 0.0001). Epiphany became more toxic with time of exposure to cells. No or minimal cytotoxicity was observed with RoekoSeal, AH Plus and EndoREZ. CONCLUSIONS: The sealers exhibited varying degrees of cytotoxicity dependent on their chemical composition.

Evaluation of post-surgical cognitive function and protein fingerprints in the cerebro-spinal fluid utilizing surface-enhanced laser Desorption/Ionization time-of-flight mass-spectrometry (SELDI-TOF MS) after coronary artery bypass grafting: review of proteomic analytic tools and introducing a new syndrome.

Cognitive dysfunction following surgery is a common complication, which increases the incidence of other co-morbid conditions, hospital and health-care costs. The reported rate of the occurrence of post-operative cognitive decline varies with different studies, depending on population profile, type of surgery, definition of cognitive disorder and detection methods, design of study, etc. It remains unclear whether these psychiatric signs and symptoms are direct results of the effects of surgery or general anesthesia. Nonetheless they are more frequent after cardiac surgery and are likely to be multi-factorial, but the patho-mechanisms are not yet fully characterized. This communication provides a synopsis of proteomics tools and delineates novel SELDI-TOF results to evaluate biomarkers in this regard. Presented for the first time is a classification of the clinically relevant forms of post-operative cognitive decline with the advent of a novel subclass.

Isolation and characterization of stem cells derived from human third molar tooth germs of young adults: implications in neo-vascularization, osteo-, adipo- and neurogenesis.

A number of studies have reported in the last decade that human tooth germs contain multipotent cells that give rise to dental and peri-odontal structures. The dental pulp, third molars in particular, have been shown to be a significant stem cell source. In this study, we isolated and characterized human tooth germ stem cells (hTGSCs) from third molars and assessed the expression of developmentally important transcription factors, such as oct4, sox2, klf4, nanog and c-myc, to determine their pluri-potency. Flow-cytometry analysis revealed that hTGSCs were positive for CD73, CD90, CD105 and CD166, but negative for CD34, CD45 and CD133, suggesting that these cells are mesenchymal-like stem cells. Under specific culture conditions, hTGSCs differentiated into osteogenic, adipogenic and neurogenic cells, as well as formed tube-like structures in Matrigel assay. hTGSCs showed significant levels of expression of sox2 and c-myc messenger RNA (mRNA), and a very high level of expression of klf4 mRNA when compared with human embryonic stem cells. This study reports for the first time that hTGSCs express developmentally important transcription factors that could render hTGSCs an attractive candidate for future somatic cell re-programming studies to differentiate germs into various tissue types, such as neurons and vascular structures. In addition, these multipotential hTGSCs could be important stem cell sources for autologous transplantation.