Effect of Nd:YAG Laser Irradiation on the Number of Open Dentinal Tubules and Their Diameter with and without Smear of Graphite: An in Vitro Study

Introduction: Dentin hypersensitivity (DH) is characterized by tooth pain arising from exposure of dental roots. In this study the efficiency of neodymium yttrium-aluminum-garnet (Nd:YAG) laser in association with graphite on dentinal surface changes as the alternative to the treatment of DH was evaluated.Methods: Sixteen noncarious human third molars were collected and sectioned into 5 parts from cementoenamel junction (CEJ) to the furcation area. The prepared samples were randomly assigned into five groups (Gs) of each 16: Control (G1), treated by Nd:YAG laser at 0.5 W (G2), irradiation of Nd:YAG with a 0.25 W output power(G3), smeared with graphite and then using Nd:YAG laser at output powers of 0.5 W (G4) and 0.25 W (G5). For all groups the parameters were 15 Hz, 60 s, at two stages and with a right angle irradiation. The number and diameter of dentinal tubules (DT) were compared and analyzed by SPSS software, One way ANOVA and Post hoc LSD tests.Results: The number of open dentinal tubules varied significantly between all groups except among G1 with G3 and G2 with G5. Multiple comparison tests also exhibited significant differences regarding the diameter of tubules between the groups two by two except among G2 with G5.Conclusion: Nd:YAG laser used at 0.25 W and 0.5 W with application of graphite smear was able to reduce the number and diameter of dentinal tubules

Cytotoxicity and Radiosensitising Activity of Synthesized Dinitrophenyl Derivatives of 5-Fluorouracil

Background and the purpose of the study: Dual functional agents in which nitroaromatic or nitroheterocyclic compounds are attached through a linker unit to mustards and aziridines have shown higher cytotoxicities than the corresponding counterparts to both aerobic and hypoxic cells and enhanced radiosensitizing activity. In thepresent investigation cytotoxicity and radiosensitizing activity of 2,4-dinitrobenzyl, 2,4-dinitrobenzoyl, and 2,4-dinitrophenacetyl derivatives of 5-fluorouracil which was assumed to release cytotoxic active quinone methidide,and 5-fluorouracil under hypoxic conditions on HT-29 cell line under both aerobic and hypoxic conditions wasinvestigated.Methods: 5-fluorouracil derivative X-XIII were prepared by the reaction of the corresponding di-nitro substitutedbenzyl, benzoyl and phenacetyl halides with 5-fluorouracil protected at N-1 with di-t-butoxydicarbonate (BOC) in dimethyl formamide (DMF) in the presence of the potassium carbonate followed by hydrolysis of the blocking,group by potassium carbonate in methanol. Cytotoxicity of fluorouracil VIII and tested compounds X-XIII against HT-29cell line under both aerobic and hypoxic conditions after 48 hrs incubation were measured by determination of the percent of the survival cells using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and percent of the dead cells using propidium iodide(PI)-digitonine assay and results were used to calculate the corresponding IC50 values. Radiosensitization experiments were carried out by irradiation of the incubations with a 60Co source and clonogenic assay was performed to determine the cell viabilities following treatment with the tested compounds and/or radiation. Sensitization Enhancement Ratio (SER) of each tested compound was obtained from the radiation survival curves in the absence and presence of each sensitizer for 37% survival respectively.Results and major conclusion: Findings of the present study showed that alkylation or acylation of 5-fluorouracilresult in compounds which have little or no cytotoxicity and radiosensitizing activity under aerobic conditions, buthave high cytotoxicity and radiosensitizing effects under hypoxic conditions. Furthermore radiosensitizing activities ofcompounds under hypoxic conditions increased by increase in their concentrations and SER of the tested 5-FU derivatives at concentrations higher than 50 μmol were equal or higher than 1.6 which is the minimum effective SER of a radiosensitizer in an in vitro assay

Fingolimod SLNs: Preparation, in vitro evaluation and Optimization of lyophilization using D-Optimal Experimental Design

Multiple Sclerosis (MS) is one of the most common neurological disorders diagnosed in young adults. there are no current cures for the disease or its underlying causes, some drugs have been developed that can decrease or delay disease progression. Fingolimod is an immunomodulating drug, mostly used for treating multiple sclerosis (MS). It approximately halves the rate of relapse in relapsing-remitting multiple sclerosis over a two-year period; however, Fingolimod causes a number of off-target effects including cardiovascular complaints. A different delivery method may alleviate some of these effects. Lipid-based nanoparticles containing Fingolimod were prepared using cholesterol as a biocompatible lipid through a high pressure homogenization technique. The physical and chemical properties of the resulting particles, including particle size, zeta potential, morphology, drug-loading capacity and release profile, were investigated. A preferred formula was lyophilized using mannitol as the cryoprotectant. A D-optimal model was used to determine optimum freeze-drying conditions that minimized size enlargement and maximized the zeta potential of the processed particles. Results: The optimized Fingolimod SLNs are 150 nm in diameter with a Zeta potential of 19 mV. AFM imaging confirms that the particles remain spherical. Fingolimid loading efficiency was found to be 89%, and 85% of the loaded drug was released over 16 days. Results demonstrated that nanotechnology could help to prolong the drug efficacy duration as well could increase compliance of patient to continue MS control, whole life duration. Conclusion: Sustained release Fingolimod SLNs using cholesterol as the matrix are effective and may provide an alternative to oral drug administration to prolong drug administering intervals and increase chance of treatment following by patients

Medium Optimization for Synaptobrevin Production Using Statistical Methods

Background: Botulinum toxin, the most potent biological toxin, has become a powerful therapeutic tool for a growing number of clinical applications. Molecular studies have identified a family of synaptic vesicle-associated membrane proteins (VAMPs, also known as synaptobrevins) which have been implicated in synaptic vesicle docking and fusion with plasma membrane proteins.Materials and Methods: Using the synaptobrevin as a substrate for in vitro assay is the method to detect BoNT activity. We have been working on optimizations of bacterial expression conditions and media for high-level production of synaptobrevin peptide. Statistics-based experimental design was used to investigate the effect of medium components (E. coli strain, peptone, IPTG, yeast extract, ampicillin, and temperature) on synaptobrevin production by E. coli.Results: A 24 fractional factorial design with center points revealed that IPTG and temperature were the most significant factors, whereas the other factors were not important within the levels tested. This purpose was followed by a central composite design to develop a response surface for medium optimization. The optimum medium composition for synaptobrevin production was found to be: IPTG 29 mM, peptone 10 g/L, yeast extract 5 g/L, temperature 23°C and ampicillin 100 mg/L. This medium was projected to produce, theoretically, 115 mg/Lsynaptobrevin.Conclusion: The optimum medium composition synaptobrevin production was found to be: BL21 (E.coli strain), LB medium (peptone 10 g/L, Yeast 5 g/L), Ampicillin (100 mg/L), IPTG (0.29 mg/L) and temperature (23°C)

Effect of Powder Sizes, pH of Water, Ultrasound and Method of Distillation on Extraction of Fennel Essential Oil and Anethole Content: Effect of some conditions on essential oil of fennel

The essential oils are frequently used in food processing industry, perfumery, cosmetics, and pharmaceuticals. Most of the oils were obtained by steam distillation and water distillation. It is necessary to specify the best conditions of essential oils production to get much more major compound(s) and higher yield oil. So, fennel oil was selected in this study. The objective of this work was to identify the effect of powder’s particle size, pH of water, method of distillation and using ultrasound on extraction of fennel essential oil (and its major constituent, anethole). We used a statistical method called D-optimal Design that appointed pH, particle size, and method for each assay. First, the seeds powder distillated directly. In the second series, the seeds were placed in an ultrasonic apparatus for 30 minutes. The essential oils were subsequently isolated by two methods, hydro-distillation, and steam-distillation in different sizes and pH in Clevenger apparatus. Gas chromatography was used to determination of major component (E-anethole) in fennel essential oils. Finally, optimum conditions according to the statistical results are as follows: Method: steam distillation, and mesh size: 50. So it shows that steam distillation is more efficiently than water distillation

VALIDATION OF 13 C-UREA BREATH TEST WITH NON DISPERSIVE ISOTOPE SELECTIVE INFRARED SPECTROSCOPY FOR THE DIAGNOSIS OF HELICOBACTER PYLORI INFECTION: A SURVEY IN IRANIAN POPULATION

ABSTRACT The urea breath test (UBT) which is carried out with 13 C or 14 C labeled urea is one of the most important non invasive methods for detection of Helicobacter pylori infection. Application of 13 C-UBT is becoming increasingly popular because of its non radioactive nature which makes it suitable for diagnostic purposes in children and women of child bearing ages. While isotope ratio mass spectrometer (IRMS) is generally used to detect 13 C in expired breath, this instrument is expensive and recently non dispersive isotope selective infrared (NDIR) spectroscopy which is a lower cost technique has been employed as a reliable counterpart for IRMS in small clinics. The aim of this study was to assess the validity of NDIR spectroscopy technique in Iranian population in comparison with histological examination, rapid urease test and 14 C-urea breath test as gold standard. Seventy six patients with dyspepsia were underwent 13 C-UBT for diagnosis of Helicobacter pylori infection. Good agreements were found between the 13 C-UBT and gold standard methods. The 13 C-UBT showed 100% sensitivity, 97.3% specificity, 97.56% positive predictive value, 100% negative predictive value and 98.65% accuracy. On the basis of these results it could be concluded that 13 C-UBT performed with NDIR spectroscopy is a reliable, accurate and non invasive diagnostic tool for detection of Helicobacter pylori infection in the Iranian population