ABSTRACT
INTRODUCTION: The aim of this study was to evaluate the biocompatibility of mineral trioxide aggregate mixed with selective hydration accelerators such as calcium chloride (CaCl2), citric acid (CA), and calcium lactate gluconate solution (CLG). METHODS: Inductively coupled plasma-atomic emission spectrometry analysis was used to measure calcium ions in the extracts of test materials. The 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide assay was performed using MG-63 cells to examine the cytotoxicity of the test materials. The surface of each sample and the growth pattern of the attached cells were observed using scanning electron microscopy (SEM). RESULTS: MTA mixed with 10 wt% CaCl2 and MTA mixed with 43.4 wt% CLG released a higher amount of calcium ions than the other groups. The 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide assay revealed that the cell viability of MTA mixed with 0.1 wt% CA was significantly higher than pure MTA on 7-day extract (P < .05). MTA mixed with 43.4 wt% CLG showed significantly higher cell viability than the other groups on 1-day extract (P < .05). MTA mixed with 10 wt% CaCl2 in all groups showed the lowest cell viability at all time points (P < .05). Under SEM, elongated and confluent cells were observed in all samples except in samples of MTA mixed with 10 wt% CaCl2. CONCLUSIONS: MTA mixed with 0.1 wt% CA showed good biocompatibility. MTA mixed with 43.4 wt% CLG showed favorable biocompatibility on 1 day. MTA mixed with 10 wt% CaCl2 in all groups showed the lowest cell viability at every time point and poor cell attachment under SEM.
Subject(s)
Aluminum Compounds/chemistry , Biocompatible Materials/chemistry , Calcium Compounds/chemistry , Osteoblasts/drug effects , Oxides/chemistry , Root Canal Filling Materials/chemistry , Silicates/chemistry , Water , Aluminum Compounds/pharmacology , Calcium/chemistry , Calcium Chloride/pharmacology , Calcium Compounds/pharmacology , Citric Acid/pharmacology , Drug Combinations , Gluconates/pharmacology , Humans , Hydrophobic and Hydrophilic Interactions , Materials Testing , Oxides/pharmacology , Root Canal Filling Materials/pharmacology , Silicates/pharmacologyABSTRACT
The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.
ABSTRACT
6-Pyruvoyltetrahydropterin synthase (PTPS) catalyzes the second step of tetrahydrobiopterin (BH4) synthesis. We previously identified PTPS orthologs (bPTPS-Is) in bacteria which do not produce BH4. In this study we disrupted the gene encoding bPTPS-I in Synechococcus sp. PCC 7942, which produces BH4-glucoside. The mutant was normal in BH4-glucoside production, demonstrating that bPTPS-I does not participate in BH4 synthesis in vivo and bringing us a new PTPS ortholog (bPTPS-II) of a bimodular polypeptide. The recombinant Synechococcus bPTPS-II was assayed in vitro to show PTPS activity higher than human enzyme. Further computational analysis revealed the presence of mono and bimodular bPTPS-II orthologs mostly in green sulfur bacteria and cyanobacteria, respectively, which are well known for BH4-glycoside production. In summary we found new bacterial PTPS orthologs, having either a single or dual domain structure and being responsible for BH4 synthesis in vivo, thereby disclosing all the bacterial PTPS homologs.
Subject(s)
Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Biopterins/analogs & derivatives , Isoenzymes/chemistry , Isoenzymes/metabolism , Phosphorus-Oxygen Lyases/chemistry , Phosphorus-Oxygen Lyases/metabolism , Amino Acid Sequence , Bacterial Proteins/classification , Bacterial Proteins/genetics , Biopterins/biosynthesis , Humans , Isoenzymes/classification , Isoenzymes/genetics , Molecular Sequence Data , Mutagenesis , Phosphorus-Oxygen Lyases/classification , Phosphorus-Oxygen Lyases/genetics , Phylogeny , Protein Conformation , Recombinant Proteins/chemistry , Recombinant Proteins/classification , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence Alignment , Synechococcus/genetics , Synechococcus/metabolismABSTRACT
A gene (slr1166) putatively encoding pteridine glycosyltransferase was disrupted with a kanamycin resistance cassette in Synechocystis sp. PCC 6803, which produces cyanopterin. The deduced polypeptide from slr1166 consisted of 354 amino acid residues sharing 45% sequence identity with UDP-glucose:tetrahydrobiopterin alpha-glucosyltransferase (BGluT) isolated previously from Synechococcus sp. PCC 7942. The knockout mutant was unable to produce cyanopterin but only 6-hydroxymethylpterin-beta-galactoside, verifying that slr1166 encodes a pteridine glycosyltransferase, which is responsible for transfer of the second sugar glucuronic acid in cyanopterin synthesis. The mutant was affected in its intracellular pteridine content and growth rate, which were 74% and 80%, respectively, of wild type, demonstrating that the second sugar residue is still required for quantitative maintenance of cyanopterin. This supports the previous suggestion that glycosylation may contribute to high cellular concentration of pteridine compounds.
