OBJECTIVES: The aim of this study was to compare apical sealing ability and physical properties of MTA, MTA - AH-plus mixture (AMTA) and experimental Portland cement - Epoxy resin mixture (EPPC) for a development of a novel retro-filling material. MATERIALS AND METHODS: Forty-nine extracted roots were instrumented and filled with gutta-percha. Apical root was resected at 3 mm and the retro-filling cavity was prepared for 3 mm depth. Roots were randomly divided into 3 groups of 15 roots each. The retro-filling was done using MTA, AMTA, and EPPC as the groups divided. Four roots were used as control groups. After setting in humid condition for 24 hours, the roots were immersed in 1% methylene blue dye solution for 72 hours to test the apical leakage. After immersion, the roots were vertically sectioned and photos were taken to evaluate microleakage. Setting times were measured with Vicat apparatus and digital radiographs were taken to evaluate aluminum equivalent thickness using aluminum step wedge. The results of microleakage and setting time were compared between groups using one-way ANOVA and Scheffe's post-hoc comparison at the significance level of 95%. RESULTS: AMTA and EPPC showed less microleakage than MTA group (p < 0.05). AMTA showed the highest radio-opacity than other groups and the novel EPPC showed 5 mm aluminum thickness radio-opacity. EPPC showed the shortest initial and final setting times than other groups while the MTA showed the longest (p < 0.05). CONCLUSIONS: Under the condition of this study, the novel composite using Portland cement-Epoxy resin mixture may useful for retro-filling with the properties of favorable leakage resistance, radio-opacity and short setting time.
Aluminum ; Glutamates ; Guanine ; Gutta-Percha ; Immersion ; Methylene Blue ; Pemetrexed

Leakage studies have been performed frequently, since a fluid-tight seal provided by various dental filling materials has been considered clinically important. The leakage of the various root-end filling materials has been widely investigated mostly dye penetration method. These dye studies cannot offer any information about the quality of the seal of a test material over a long period of time The purpose of this study was to evaluate the microleakage of root end cavities in blood contamination filled amalgam, intermediate restorative material(IRM), light cured glass ionomer cement(GI) and mineral trioxide aggregate(MTA) by means of a modified fluid transport model. Fifty standard human root sections, each 5mm high and with a central pulp lumen of 3mm in diameter, were and filled with our commonly used or potential root end filling materials after they were contaminated with blood. At 24h, 72h, 1, 2, 4, 8, and 12 weeks after filling, leakage along these filling materials was determined under a low pressure of 10KPa(0.1atm) using a fluid transport model. The results were as follows: 1. MTA group showed a tendency of decreasing percent of gross leakage (20ml/day) in process of time, whereas the other materials showed a tendency of increasing in the process time. 2. At the all time interval, GI group leaked significantly less than amalgam group and IRM group (p<0.05). 3. At the 4 weeks, the percentage of gross leakage in MTA group decreased to 0% thereafter, the low percentage of gross leakage was maintained in MTA group until the end of the experiment, whereas the percentage in IRM group increased to 100%. 4. At the 12 weeks, percentage of gross leakage was significantly low in MTA group(0%), comparison with GI group(40%), amalgam group(90%) and IRM group(100%), but there was no significant difference between latter two materials.
Acrylic Resins ; Glass ; Glutamates ; Guanine ; Humans ; Light ; Silicon Dioxide ; Pemetrexed

PURPOSE: Glutamate and aspartate are the excitatory amino acid neurotransmitters and NMDA (N-methyl-D-aspartate) is one of their major receptors. NMDA agonist may sti mulate serotonergic nervous system that inhibit the penile erection as well as induce the penile erection. We investigate the effects of NMDA agonist on serotonin release from hippocampus. MATERIALS AND METHODS: The slices of hippocampus were incubated in a buffer con taining 0.1mM [(3)H]5-hydroxytryptamine (5-HT) for uptake in the male rat. The release of 5-HT into the buffer during each 10 minutes period was measured and the radio activities in each buffer and the tissue were counted. After 50 min from the initiation, NMDA agonist were administered at 6th and 7th 10 min period respectively. The changes of 5-HT release were expressed as percent values compared to the 5th 10 min period. Tetrodotoxin was used to determine the possible involvement of interneuron on the action of these neurotransmitters. RESULTS: A steady release of 5-HT was observed up to 100 minutes after the rapid release during the first 40 minutes. Treatment of tetrodotoxin (10(-6)M) did not change the spontaneous release of 5-HT. The 5-HT released during 10 and 20 minutes of NMDA agonist (10(-4M)) treatment significantly higher than those of control group. The increase of 5-HT release by NMDA agonist was blocked by pretreatment with tetro dotoxin. The release of 5-HT was increased by NMDA agonist and this response was blocked by tetrodotoxin. CONCLUSIONS: NMDA agonist increases the release of 5-HT through the activation of the interneurons and these results suggest that NMDA agonist may stimulate the serotonergic nervous system that inhibit the penile erection as well as inducing the penile erection.
Animals ; Aspartic Acid ; Excitatory Amino Acids ; Glutamic Acid ; Hippocampus* ; Humans ; Interneurons ; Male ; N-Methylaspartate* ; Nervous System ; Neurotransmitter Agents ; Penile Erection ; Rats* ; Serotonin* ; Tetrodotoxin

The purpose of this study was, first, to devise a new model for topical application of excitatory amino acids(EAAs) to rat cerebral cortex that successfully and repeatdly initiate the cortical spreading depression(CSD). Then, by using this model, six major EAAs that are known to act on single or multiple subtypes of EAA receptor were examined; glutamate, kainate, aspartate, N-methyl-D-aspartate(NMDA), quisqualate, and alpha-amino-3-hydroxy-5-methyl-4-isoxazoie-proprite(AMPA). Through the model, with a cone-shaped well buried in 1.5mm depth of the cerebral cortex, these chemical agents were topically applied to the cortical gray matter. A total of 50 Sprague-Dawley rats were used and divided into seven groups including the sham group. Doses of each EAA between 10(-7) and 10(-4)M concentrations were escalated for triggering the CSD and its rate of consistency in triggering was also evaluated. In the overall results. CSDs were repeatedly initiated in all experimental groups with relatively consistent rates. Duration of CSDs were 1-4 minutes(mean 2.2+/-1.4) and amplitudes were 20-40mV. Effective dose(50)(ED(50)), that trigger over 50% of CSD was 10(-5)M(n=8) for glutamate, 10(-7)M(n=8) for aspartate, 10(-5)M(n=7) for AMPA, 10(-5)M(n=7) for quisqualate, and 10(-4)M(n=7) for NMDA and kainate group. Among those acting on the single receptor, AMPA was shown to be the most effective in triggering CSD, and NMDA, and kainate were in descending orders. Aspartate that was known to act on multiple EAA receptors, showed the highest rate of triggering CSD among all groups, but glutamate, known to act on all receptors of its subtypes, showed the most consistent rate of triggering CSD at dose escalation. These results revealed that those EAA acting on multiple receptors, namely aspartate and glutamate, showed the highest and most consistent rate of triggering CSD. Among those acting on single channel of receptors. AMPA was the most effective, although its consistency and rate of triggering of CSD was somewhat lower than.
alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid ; Animals ; Aspartic Acid ; Cerebral Cortex ; Cortical Spreading Depression* ; Excitatory Amino Acids* ; Glutamic Acid ; Kainic Acid ; N-Methylaspartate ; Quisqualic Acid ; Rats ; Rats, Sprague-Dawley ; Receptors, AMPA

Analysis of leaf exudates of Vicia faba using paper chromatography to identify individual amino acids and sugars qualitatively was investigated. The results revealed that the number of identified amino acids detected in the leaf exudates of the susceptible plants was more than those of resistant plants. The results also showed an increase in the number of amino acids exuded by infected leaves, but no marked difference in sugars of infected and non infected plants. Lithium chloride application led to decrease in amino acid and sugar contents. The number of amino acids and sugars was also decreased with leaf age. Botrytis fabae and the selected fungal species (Alternaria alternata, Fusarium oxysporum and Aspergillus niger) were used to show the effect of individual amino acid and sugar on their spore germination. It was observed that all amino acids stimulated the fungal spore germination except serine which inhibited its spore germination. In case of A. alternata, spore germination was stimulated by all amino acids except serine, alanine, glutamic acid, arginine and methionine which caused the inhibition. In case of F. oxysporum, aspartic and glutamic acids inhibited spore germination but the other amino acids stimulated its spore germination. Aspartic acid and phenyl alanine inhibited the spore germination of A. niger. All the identified sugars (galactose, glucose, fructose and rhamnose) stimulated spore germination of all tested fungi.
Alanine ; Amino Acids ; Arginine ; Aspartic Acid ; Aspergillus ; Botrytis* ; Carbohydrates ; Chromatography, Paper ; Exudates and Transudates* ; Fructose ; Fungi* ; Fusarium ; Germination ; Glucose ; Glutamates ; Glutamic Acid ; Lithium Chloride ; Methionine ; Niger ; Serine ; Spores ; Spores, Fungal ; Vicia faba* ; Vicia*

We identified a neuroprotective single fraction among 62 ones of hexane extract from Uncaria sinensis (JGH43IA) and investigated its effects and mechanisms in primary cortical neurons. Pretreatment with JGH43IA showed a significantly increase cell viability in a dose-dependent manner with a decrease in the lactate dehydrogenase release. When we performed morphological assay and flow cytometry to determination of the type of cell death, pretreatment with JGH43IA showed a significant reduction of glutamate-induced apoptotic cell death. Then we explored the downstream signaling pathways of N-methyl-D-aspartate receptor (NMDAR) with calpain activation to elucidate possible pathways of neuroprotection by JGH43IA. Pretreatment with JGH43IA exhibited a significant attenuation of NMDAR GluN2B subunit activation and a decrease in active form of calpain 1 leading to subsequent cleavage of striatal-enriched protein tyrosine phosphatase (STEP). In addition, pretreatment with JGH43IA showed a marked increase of cAMP responsive element binding protein. These results suggest that JGH43IA may have neuroprotective effects through down-regulation of NMDAR GluN2B subunit and calpain 1 activation, and subsequent alleviation of STEP cleavage. This single fraction from U. sinensis might be a useful therapeutic agent for brain disorder associated with glutamate injury.
Brain Diseases ; Calpain ; Carrier Proteins ; Cell Death ; Cell Survival ; Down-Regulation ; Flow Cytometry ; Glutamates ; Glutamic Acid ; L-Lactate Dehydrogenase ; N-Methylaspartate ; Neurons* ; Neuroprotective Agents* ; Protein Tyrosine Phosphatases ; Receptors, N-Methyl-D-Aspartate ; Uncaria*

No abstract available.
Pemetrexed

The purpose of this study was to compare the dye leakage of MTA (mineral trioxide aggregate) apical plug produced by two orthograde placement techniques (hand condensation technique and ultrasonically assisted hand condensation technique). To simulate straight canal, 60 transparent acrylic blocks with straight canal were fabricated. These transparent acrylic blocks were divided into 2 groups (Group C; hand condensation technique (HC) and Group U; ultrasonically assisted hand condensation technique (UAHC)) of 30 blocks with each MTA application method. Each group was divided into 2 subgroups (n = 15) with different canal size of #70 (subgroup C70 and subgroup U70) and #120 (subgroup C120 and subgroup U120). After apical plug was created, a wet paper point was placed over the MTA plug and specimen was kept in a humid condition at room temperature to allow MTA to set. After 24 hours, remaining canal space was backfilled using Obtura II. All specimens were transferred to floral form socked by 0.2% rhodamine B solution and stored in 100% humidity at room temperature. After 48 hours, resin block specimens were washed and scanned using a scanner. The maximum length of microleakage was measured from the scanned images of four surfaces of each resin block using Photoshop 6.0. Statistical analysis was performed with Mann-Whitney U test. Group U of UAHC had significantly lower leakage than Group C of HC in #70-size canal (subgroup U70) (p < 0.05).
Glutamates ; Guanine ; Hand ; Humidity ; Rhodamines ; Root Canal Filling Materials ; Ultrasonics ; Pemetrexed

Mineral trioxide aggregate (MTA), which was originally developed for repair of root perforations, is a biocompatible material with numerous clinical applications in endodontics. MTA must be allowed to set in the presence of moisture to optimize the material's physical and chemical properties. In the clinic, occasionally unset MTA has been detected after application of MTA on the tooth, and the reason has been unclear. This case report presents MTA washed-out for several years after placement at the root apex as an apical plug, and discusses the reason and things to consider in clinics.
Aluminum Compounds ; Calcium Compounds ; Drug Combinations ; Endodontics ; Glutamates ; Guanine ; Oxides ; Silicates ; Tooth ; Pemetrexed

MTA is rarely applied in the repair of root fractured section. A case of maxillary second premolar which fractured ten years ago had been connected with MTA in this article and the cone beam CT was used to evaluate the treatment effect.
Bicuspid ; Cone-Beam Computed Tomography ; Glutamates ; Guanine ; analogs & derivatives ; Humans ; Pemetrexed ; Tooth Root