RESUMEN

BACKGROUND: Vital pulp therapy, based on the use of stem cells, has promising research and therapeutic applications in dentistry. It is essential to understand the direct effect of capping materials on the dental pulp stem cells of primary teeth, which contribute to the healing powers of the tooth. The aim of this study is to evaluate the effect of different capping materials (Calcium Hydroxide (DyCal®) - Glass Ionomer (Fuji IX®) and light-cured resin modified calcium silicate (TheraCal LC®)) on the viability, proliferation, and differentiation of stem cells from human exfoliated deciduous teeth (SHEDs). METHODS: SHEDs were isolated from extracted primary teeth, then divided into four groups and each of the capping materials were applied to the stem cells as follows: group I the controls, group II with Ca(OH)2, group III with the GIC, and group IV with the Theracal LC. For all groups assessment of viability and proliferation rate was done using the MTT cell proliferation assay. Also, Differentiation was evaluated by measuring the gene expression of Alkaline phosphatase enzyme activity (ALP) and Dentin matrix protein-1 (DMP1) through quantitative real-time PCR. Morphological assessment was conducted using Alizarin Red S staining. All evaluations were performed after 7 and 14 days of culture. RESULTS: TheraCal LC showed the highest values of proliferation, which was significant only compared to the control group after 2 weeks (p = 0.012). After one week, TheraCal LC showed the highest significant values of ALP and DMP1 compared to all other groups (p < 0.001). CONCLUSION: The three materials under study are biocompatible, maintain viability, and stimulate the proliferation and differentiation of SHEDs. However, TheraCal LC allows better proliferation of SHEDs than Dycal Ca(OH)2 and Fuji IX GIC.

Asunto(s)

RESUMEN

BACKGROUND: Egypt has one of the highest prevalence of hepatitis C virus (HCV) worldwide. Ophthalmological side effects are recognized complications of interferon (IFN) therapy. This study aimed to evaluate IFN-induced ophthalmological manifestations in patients receiving PEGylated interferon (PEG IFN) and ribavirin (RBV) and to assess the effect of IFN duration, response and systemic risk factors on the severity. METHODS: We retrospectively analyzed 100 patients with chronic HCV who were candidates for PEG-IFN and RBV therapy. All patients were subjected to clinical and ophthalmological examination, laboratory investigations, abdominal ultrasound, colored fundus photography and fundus fluorescein angiography, follow up was made at weeks 12, 24, and 48 of treatment. RESULTS: IFN-induced retinopathy had been found in (9/100; 9%), 5 (5/9; 55.5%) of them had bilateral lesions, (3/9; 33.3%) were treatment responders and (6/9; 66.6%) non responders. The time of retinopathy appearance was mainly at W12. Retinopathy was asymptomatic in most of the affected patients (7/9; 77.77%) and reversible, cotton wool spots was the major associated sign. Patients with older age, DM and or HTN, and non-responders to antiviral therapy were associated with more severe retinopathy. CONCLUSIONS: Retinopathy is not a rare complication of IFN therapy for chronic HCV infection, but fortunately it's asymptomatic and reversible. Ophthalmological assessment at base-line and at follow up during IFN treatment is very important.

RESUMEN

Objective. To assess the knowledge, awareness, and attitudes of dental faculty regarding research ethics and research ethics committees (RECs). Design. Through convenience sampling, we distributed a survey to academics at dental faculties at two universities in the Middle East. We used descriptive, chi-square, and logistic regression statistics to analyze the data. Results. Our response rate was 62.5%. A large majority (>90%) held positive attitudes towards RECs; however, almost half (44.0%) thought that RECs would delay research. Less than half (36.8%) had received prior training in research ethics, and the average score they achieved on the questions on research ethics was only 40.2%. Most (>90%), however, were favorable towards research ethics education. Finally, some faculty held attitudes regarding certain research ethics practices that were not optimal. Conclusions. We conclude that among the dental faculties participating in our study, there is broad-based acceptance of RECs and training in research ethics, while there are knowledge gaps in research ethics. We recommend further studies to determine the generalizability of our findings to other institutions.

RESUMEN

The objectives of this paper are to (1) quantify variability in hourly utility oxides of nitrogen (NO(x)) emission factors, activity factors, and total emissions; (2) investigate the autocorrelation structure and evaluate cyclic effects at short and long scales of the time series of total hourly emissions; (3) compare emissions for the ozone (O3) season versus the entire year to identify seasonal differences, if any; and (4) evaluate interannual variability. Continuous emissions monitoring data were analyzed for 1995 and 1998 for 32 units from nine baseload power plants in the Charlotte, NC, airshed. Unit emissions have a strong 24-hr cycle attributable primarily to the capacity factor. Typical ranges of the coefficient of variation for emissions at a given hour of the day were from 0.2 to 0.45. Little difference was found when comparing weekend emissions with the entire week or when comparing the O3 season with the entire year. There were substantial differences in the mean and standard deviation of emissions when comparing 1995 and 1998 data, indicative of the effect of retrofits of control technology during the intervening time. The wide range of variability and its autocorrelation should be accounted for when developing probabilistic utility emission inventories for analysis of near-term future episodes.

Asunto(s)