Trace metal contents of three tricalcium silicate materials: MTA Angelus, Micro Mega MTA and Bioaggregate.

AIM: To investigate the levels of nine metals [aluminium (Al), antimony (Sb), arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), iron (Fe), lead (Pb) and molybdenum (Mo)] in MTA Angelus, Micro Mega MTA and Bioaggregate using inductively coupled plasma-optical emission spectrometry (ICP-OES). METHODOLOGY: Each material (0.2 g) was digested using a mixture of hydrochloric and nitric acids and then filtered. The levels of nine metals in the resulting filtrates were measured by ICP-OES. The results were statistically analysed using one-way anova and the Bonferroni test. RESULTS: MTA Angelus contained more aluminium, beryllium and chromium than Micro Mega MTA (P < 0.05), whilst their levels of arsenic, cadmium and iron were similar. Antimony, lead and molybdenum were not detected in any of the three tested cements. Bioaggregate contained trace amounts of aluminium. CONCLUSIONS: MTA Angelus and Micro Mega MTA contained small amounts of seven tested metal oxides. Bioaggregate only contained trace amounts of aluminium.

Indicative factors for surgical or angiographic intervention in hemodynamically stable patients with blunt abdominal trauma: A retrospective cohort study.

INTRODUCTION: The standard of care for intraperitoneal injury in hemodynamically stable patients after blunt abdominal trauma has been replaced by non-operative management (NOM). However, selective NOM, depending on the situation, seems necessary in determining the treatment plan. In this study, we attempted to identify risk factors for surgical or angiographic intervention (SAI) in hemodynamically stable blunt abdominal trauma patients. METHODS: This retrospective study which included adult patients who were brought to a regional trauma center was conducted from March 2015 to October 2019. We evaluated the characteristics of blunt abdominal trauma patients and analyzed factors that were related to the requirement of SAI in these patients. Patients were divided into SAI and conservative management (CM) groups. RESULTS: We reviewed 1,176 patients, and after exclusions, of whom 248 blunt abdominal trauma and free fluid observed on CT were identified. The mean pulse rate was higher in the SAI than in the CM (P=0.025). Laboratory findings showed that lactate and delta neutrophil index (DNI) levels were higher in the SAI than in the CM (P=0.002 and 0.026 respectively). Additionally, the mean free fluid size in the SAI (85.69mm) was significantly larger than that in the CM (68.12mm; P=0.001), and blush was more frequently observed in the SAI (P<0.001). In multivariate analysis, only blush was an independent prognostic factor for SAI (OR 11.7, 95% CI, 5.1-30.8, P<0.001). CONCLUSION: In hemodynamically stable patients with blunt abdominal trauma, blush but also high lactate and DNI are associated with the requirement of interventional radiology and/or surgery.

Phase II study of S-1 combined with oxaliplatin as therapy for patients with metastatic biliary tract cancer: influence of the CYP2A6 polymorphism on pharmacokinetics and clinical activity.

BACKGROUND: Advanced biliary cancer is often treated with fluoropyrimidine-based chemotherapy. In this study, we evaluated the efficacy and tolerability of a combination of S-1, an oral fluoropyrimidine prodrug, and oxaliplatin in patients with metastatic biliary cancer. METHODS: Patients with histologically confirmed metastatic biliary cancer and no history of radiotherapy or chemotherapy were enrolled. Oxaliplatin was administered intravenously (130 mg m(-2)), followed by 14-day administration of oral S-1 (40 mg m(-2) twice daily) with a subsequent 7-day rest period every 21 days. Pharmacokinetic analysis of S-1 was performed at cycle 1. Patients were genotyped for CYP2A6 polymorphisms ((*)1, (*)4, (*)7, (*)9 or (*)10), and pharmacokinetic and clinical parameters compared according to the CYP2A6 genotype. RESULTS: In total, 49 patients were evaluated, who received a median of four cycles. The overall response rate was 24.5%. Median progression-free and overall survival was 3.7 and 8.7 months, respectively. The most common haematological grade 3 out of 4 toxicity was neutropenia (14%), while non-hematological grade 3 out of 4 toxicities included anorexia (14%), nausea (12%), asthenia (10%), vomiting (10%), and diarrhoea (4%). Biotransformation of S-1 (AUC(0-24 h) of 5-fluorouracil/AUC(0-24 h) of tegafur) was 1.85-fold higher for the *1/*1 group than for the other groups (90% confidence interval 1.37-2.49). Diarrhoea (P=0.0740), neutropenia (P=0.396), and clinical efficacy (response rate, P=0.583; PFS, P=0.916) were not significantly associated with CYP2A6 genotype, despite differences in 5-FU exposure. CONCLUSION: The combination of S-1 and oxaliplatin appears to be active and well tolerated in patients with metastatic biliary cancer, and thus is feasible as a therapeutic modality. CYP2A6 genotypes are associated with differences in the biotransformation of S-1. However, the impact of the CYP2A6 polymorphism on variations in clinical efficacy or toxicity requires further evaluation.

Ethnic differences and relationships in the oral pharmacokinetics of nifedipine and erythromycin.

OBJECTIVE: Our objective was to investigate ethnic differences in the oral pharmacokinetics of nifedipine and erythromycin, both typical cytochrome P4503A (CYP3A) substrates, in Koreans and Caucasians and to identify the nature of any correlations between the pharmacokinetic parameters of the two drugs. METHODS: Twenty healthy male volunteers (10 Koreans and 10 Caucasians) received single oral doses of nifedipine (10 mg) or erythromycin (500 mg) in a randomized 2-way crossover study. Pharmacokinetic evaluations were performed, and parameters were compared for the two ethnic groups. During the nifedipine study period, hemodynamic measurements were conducted to determine the pharmacodynamic relevance of the pharmacokinetic differences. RESULTS: Koreans showed area under the concentration-time curves (AUCs) for both drugs that were 1.6 to 1.7 times higher than those of Caucasians. This difference decreased to 1.3 when normalized for body weight. Significant correlation between the AUCs of the two drugs was not evident. Hemodynamic changes after nifedipine administration paralleled those of the pharmacokinetic differences, with significantly greater decreases in blood pressure and total peripheral resistance noted in Koreans. CONCLUSIONS: Koreans showed significantly lower oral clearances of nifedipine and erythromycin, probably because of genetic differences attributed to the CYP3A enzymes.

Effect of omeprazole on the pharmacokinetics of moclobemide according to the genetic polymorphism of CYP2C19.

BACKGROUND: Moclobemide, an antidepressant with selective monoamine oxidase-A inhibitory action, is known to be metabolized by CYP2C19 and is also reported to be an inhibitor of CYP2C19, CYP2D6, and CYP1A2. To confirm the involvement of CYP2C19, we performed a pharmacokinetic interaction study. METHODS: The effect of omeprazole on the pharmacokinetics of moclobemide was studied in 16 healthy volunteers. The volunteer group comprised 8 extensive metabolizers and 8 poor metabolizers of CYP2C19, which was confirmed by genotyping. Subjects were randomly allocated into two sequence groups, and a single-blind, placebo-controlled, two-period crossover study was performed. In study I, a placebo was orally administered for 7 days. On the eighth morning, 300 mg of moclobemide and 40 mg of placebo were coadministered with 200 mL of water, and a pharmacokinetic study was performed. During study II, 40 mg of omeprazole was given each morning instead of placebo, and pharmacokinetic studies were performed on the first and eighth day with 300 mg of moclobemide coadministration. RESULTS: The inhibition of moclobemide metabolism was significant in extensive metabolizers even after a single dose of omeprazole. After daily administration of omeprazole for 1 week, the pharmacokinetic parameters of moclobemide and its metabolites in extensive metabolizers changed to values similar to those in poor metabolizers. In poor metabolizers, no remarkable changes in the pharmacokinetic parameters were observed. CONCLUSION: Our results show that CYP2C19 is an important enzyme in the elimination of moclobemide and that it is extensively inhibited by omeprazole in extensive metabolizers, but not in poor metabolizers.

Molecular cloning of chitinase cDNAs from the silkworm, Bombyx mori and the fall webworm, Hyphantria cunea.

cDNAs encoding chitinases were cloned and characterized from Bombyx mori and Hyphantria cunea, and their gene expression during the metamorphosis was also studied. The chitinase cDNA from B. mori encodes a protein of 565 amino acids with a calculated molecular mass of 63.4 kDa and the H. cunea chitinase cDNA encodes a protein of 553 amino acids with a calculated molecular mass of 62.0 kDa. Amino acid alignment of the two chitinases revealed 75% homology and 77-80% with M. sexta chitinase. The putative cleavage site of the signal peptide was between amino acid residues 20 and 21 for both chitinases. There were three potential N-glycosylation sites in the chitinase of B. mori at the amino acid residues 86-89, NFTS 304-307, NATG, 398-401, NYTV, whereas two potential N-glycosylation sites were present at the amino acid residues 86-89, NFTA and 304-307, NATG, in that of H. cunea. Southern blot analysis of total genomic DNA suggested that the B. mori genome has only one chitinase gene detectable by the cDNA probe and the H. cunea genome has one or two chitinase gene copies. Northern analysis indicated that gene expression was up-regulated during the molting process, larval-pupal transformation and pupal-adult transformation, when enzymatic degradation of cuticle was occurring.

Identification of a cryptic N-terminal signal in Saccharomyces cerevisiae peroxisomal citrate synthase that functions in both peroxisomal and mitochondrial targeting.

Saccharomyces cerevisiae has three distinct citrate synthases, two located in mitochondria (mature Cit1p and Cit3p) and one in peroxisomes (mature Cit2p). While the precursor of the major mitochondrial enzyme, Cit1p, has a signal for mitochondrial targeting at its N-terminus (MTS), Cit2p has one for peroxisomal targeting (PTS1) at its C-terminus. We have previously shown that the N-terminal segment of Cit2p is removed during import into peroxisomes [Lee, H.S. et al. (1994) Kor. J. Microbiol. 32, 558-564], which implied the presence of an additional N-terminal sorting signal. To analyze the function of the N-terminal region of Cit2p in protein trafficking, we constructed the N-terminal domain-swapped versions of Cit1p and Cit2p. Both fusions, Cit1::Cit2 and Cit2::Cit1, complemented the glutamate auxotrophy caused by the double-disruption of the CIT1 and CIT2 genes. In addition, part of the Cit2::Cit1 fusion protein, as well as Cit1::Cit2, was shown to be transported into both mitochondria and peroxisomes. The subcellular localization of the recombinant fusion proteins containing various N-terminal segments of Cit2p fused to a mutant version of green fluorescent protein (GFP2) was also examined. As a result, we found that the 20-amino acid N-terminal segment of Cit2p contains a cryptic cleavable targeting signal for both peroxisomes and mitochondria. In addition, we show that the peroxisomal import process mediated by the N-terminal segment of Cit2p was not affected by the disruption of either PEX5 (encoding PTS1 receptor) or PEX7 (encoding PTS2 receptor).

Pharmacokinetic/pharmacodynamic evaluation of a novel potassium channel opener, SKP-450, in healthy volunteers.

To evaluate the pharmacokinetic/pharmacodynamic characteristics of SKP-450, a novel K+ channel opener, a single blind, randomized, placebo-controlled, dose-rising, parallel-group study was conducted in 28 healthy volunteers. The volunteers were randomly allocated to dosage groups of 50 micrograms, 100 micrograms, 200 micrograms, and 300 micrograms. Single doses of SKP-450 were administered orally, after overnight fasting, and serial blood sampling and pharmacodynamic measurements were performed up to 48 hours after the drug was administered. The 200 micrograms group was further studied for food interactions in a crossover fashion. Drug concentrations in plasma were determined by HPLC. Hemodynamic changes after drug administration were evaluated by serial measurements of blood pressure (BP), pulse rate (PR), cardiac index (CI), and total peripheral resistance (TPR), using computerized impedance cardiography. Changes in plasma renin activity (PRA) and aldosterone concentrations (PAC) were determined 4 and 24 hours after drug administration. Both SKP-450 and SKP-818, an active metabolite, showed linear pharmacokinetic characteristics, and food intake did not significantly affect the pharmacokinetic characteristics of either compound. Dose-related pharmacological effects were obvious for both the 200 micrograms and 300 micrograms groups. Hemodynamic parameters related to vasodilation and reflex tachycardia, such as maximum changes in diastolic BP, PR, CI, and TPR, showed significant dose-dependent changes. The area under the time-effect curve (AUEC) of the parameters also showed a similar dose-dependent pattern. The PRA and PAC exhibited significant changes 4 hours after drug administration in the 300 micrograms group. Adverse effects, such as headaches, were more frequently observed at the higher dose levels. SKP-450 was generally well tolerated by these normotensive subjects. The antihypertensive efficacy of SKP-450 needs to be evaluated in hypertensive patients after multiple dosing.

Cloning and characterization of chitin synthase gene fragments from Penicillium chrysogenum.

DNA fragments homologous to chitin synthase were amplified from the genomic DNA of Penicillium chrysogenum by PCR. Cloning and sequencing of the PCR-amplified fragments led to the identification of four different genes, designated PcCHS1, PcCHS2, PcCHS3, and PcCHS4. By comparison of the deduced amino acid sequences, PcCHS1 was identified as a gene for class I chitin synthase, PcCHS2 and PcCHS3 were for class II, and PcCHS4 was for class III. Among these only PcCHS4 includes an intervening sequence of 56 bp. The analysis of the deduced amino acid sequences revealed a close evolutionary relationship between Penicillium and ascomycetous fungi.

Cloning and phylogenetic analysis of chitin synthase genes from the insect pathogenic fungus, Metarhizium anisopliae var. anisopliae.

Degenerated PCR primers were used to amplify chitin synthase genes from genomic DNA of Metarhizium anisopliae var. anisopliae. Through cloning and sequencing of approximately 600-bp fragments amplified by PCR, we found three genes encoding different types of chitin synthases, designated MaCHS1, MaCHS2, and MaCHS3. Southern blot analysis performed on genomic DNA showed that each of the chitin synthases MaCHS1, MaCHS2, and MaCHS3 is encoded by a single copy gene. Alignment of their deduced amino acid sequences with those of other euascomycetes separated the sequences into three distinct classes. MaCHS1 was identified as a gene for class I chitin synthase, MaCHS2 for class II, and MaCHS3 for class III. The UPGMA dendrogram and phylogenetic tree of the deduced amino acid sequences revealed the taxonomic and evolutionary position of Metarhizium anisopliae var. anisopliae.

Flow cytometric analysis and chromosome sorting of barley (hordeum vulgare L).

Flow cytometric analysis was systematically performed to optimize the concentration and duration of hydroxyurea (DNA synthesis inhibitor) and trifluralin (metaphase blocking reagent) treatments for synchronizing the cell cycle and accumulating metaphase chromosomes in barley root tips. A high metaphase index (76.5% in the root tip meristematic area) was routinely achieved. Seedlings of about 1.0-cm length were treated with 1.25 mM hydroxyurea for 14 h to synchronize the root tip meristem cells at the S/G2 phase. After rinsing with hydroxyurea, the seedlings were incubated in a hydroxyurea-free solution for 2 h and were treated with 1 microM trifluralin for 4 h to accumulate mitotic cells in the metaphase. The consistent high metaphase index depended on the uniform germination of seeds prior to treatment. High-quality and high-quantity isolated metaphase chromosomes were suitable for flow cytometric analysis and sorting. Flow karyotypes of barley chromosomes were established via univariate and bivariate analysis. A variation of flow karyotypes was detected among barley lines. Two single chromosome types were identified and sorted. Bivariate analysis showed no variation among barley individual chromosomes in AT and GC content.

Detection of laryngeal function using speech and electroglottographic data.

The purpose of this research was to develop quantitative measures for the assessment of laryngeal function using speech and electroglottographic (EGG) data. We developed two procedures for the detection of laryngeal pathology: 1) a spectral distortion measure using pitch synchronous and asynchronous methods with linear predictive coding (LPC) vectors and vector quantization (VQ) and 2) analysis of the EGG signal using time interval and amplitude difference measures. The VQ procedure was conjectured to offer the possibility of circumventing the need to estimate the glottal volume velocity wave-form by inverse filtering techniques. The EGG procedure was to evaluate data that was "nearly" a direct measure of vocal fold vibratory motion and thus was conjectured to offer the potential for providing an excellent assessment of laryngeal function. A threshold based procedure gave 75.9 and 69.0% probability of pathological detection using procedures 1) and 2), respectively, for 29 patients with pathological voices and 52 normal subjects. The false alarm probability was 9.6% for the normal subjects.

Perforation repair comparing mineral trioxide aggregate and amalgam using an anaerobic bacterial leakage model.

The purpose of this study was to evaluate the ability of mineral trioxide aggregate (MTA) and amalgam to seal furcal perforations in extracted human molars using an anaerobic bacterial leakage model. Furcal perforations were made in 39 maxillary and mandibular human molars with a high-speed bur. These were randomly divided into two experimental groups of 18, with the remaining three teeth used as positive controls. Experimental group 1 was repaired with MTA and group 2 with amalgam. Three additional teeth without perforations served as negative controls. A dual chamber anaerobic bacterial leakage model was assembled. Brain heart infusion broth with yeast extract, hemin, menadione, and the chromogenic indicator bromcresol purple was used as the culture broth for Fusobacterium nucleatum. Eight of 18 amalgam samples leaked, whereas none of the 18 MTA samples leaked. MTA was significantly better than amalgam in preventing leakage of F. nucleatum past furcal perforation repairs.

Development of an anaerobic bacterial leakage model.

The majority of bacteria associated with infections of endodontic origin are strict anaerobes. The purpose of this study was to develop an endodontic microleakage model using strict anaerobic bacteria in a two-chamber system. Nine species of anaerobic bacteria were tested for viability and detection by either turbidity or color change of the broth. A survey of pH chromogenic substrates revealed that bromcresol purple (pH 5.2 = yellow, pH 6.8 = purple) could be used as a chromogenic indicator to detect the growth of anaerobic bacteria. Peptone-yeast extract-glucose broth (PYG) and brain heart infusion broth (BHI) were each used alone and with bromcresol purple (bpPYG, bpBHI) in this study. Fusobacterium nucleatum and F. necrophorum were viable in all four media for > 2 wk and produced both turbidity and a color change after only 1 day of incubation. Veillonella parvula in either bpBHI or BHI and Peptostreptococcus anaerobius in either bpPYG or BHI were viable for > 2 wk and showed a color change or turbidity after 1 or 2 days. The results indicate that leakage of strict anaerobes may be evaluated in a two-chamber system.

Association of black-pigmented bacteria with endodontic infections.

Black-pigmented bacteria (BPB) have been associated with endodontic infections. The purpose of this study was to evaluate further the presence of BPB with the clinical signs and symptoms associated with endodontic infections. Microbial samples were collected from the root canals of 40 intact teeth with necrotic pulps and apical periodontitis. Conventional laboratory methods were used for identification of the strains of BPB isolated in pure culture. In addition, the polymerase chain reaction and specific primers for 16S r-RNA genes were used to differentiate Prevotella nigrescens from Prevotella intermedia. Twenty-two (55%) samples were positive for the growth of BPB. Of those, 11 of 22 (50%) were identified as P. nigrescens, 8 of 22 (36%) were P. intermedia, 2 of 22 (9%) were Porphyromonas gingivalis, and 1 of 22 (5%) was Prevotella melaninogenica. Sixteen of the 22 root canals positive for the growth of BPB were associated with purulent drainage either from the root canal or an associated sinus tract. Statistical analysis did not show a significant relationship for the presence of BPB with clinical signs and symptoms.

Occurrence of Prevotella nigrescens and Prevotella intermedia in infections of endodontic origin.

The occurrence of Prevotella intermedia and Prevotella nigrescens in endodontic infections was studied using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole cell protein to distinguish between the species. Previous studies have shown an association between black-pigmented bacteria (BPB) and endodontic infections and that Prevotella intermedia (previously known as Bacteroides intermedius) was the most commonly isolated BPB. Recently, however, strains identified as P. intermedia were shown to in fact be composed of two separate species, P. intermedia and P. nigrescens. Fifty-six strains of BPB isolated from endodontic infections and previously identified as P. intermedia were used in this study. Following SDS-PAGE, P. nigrescens showed a unique 18.6 kDa band that was used to differentiate P. nigrescens from P. intermedia. Of the 56 strains of BPB, 41 (73.2%) were identified as P. nigrescens and 15 (26.8%) as P. intermedia. This study confirms that P. nigrescens, and not P. intermedia, is the BPB most often isolated from infections of endodontic origin.

Black-pigmented bacteria in coronal and apical segments of infected root canals.

Black-pigmented bacteria (BPB) have been associated with infections of endodontic origin. The purpose of this study was to culture and identify BPB from the apical and coronal segments of infected root canals to understand better their ecological relationships. Teeth with a periapical radiolucency were extracted and immediately placed in reduced transport fluid for transport to an anaerobic chamber. Of 18 sampled roots, 12 were positive for the growth of BPB. Eight of the 12 roots with BPB had a carious exposure of the pulp chamber. Seven roots had Prevotella nigrescens in both the apical and the coronal segments. Six of these seven teeth had carious exposures of the pulp chamber. Of the 12 roots infected with BPB, six roots had two different species of BPB, with P. nigrescens always being one of the species. P. nigrescens was the most often isolated BPB from both the coronal and apical segments of infected root canals.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and polymerase chain reaction for differentiation of Prevotella intermedia and Prevotella nigrescens.

Isolates previously thought to be Prevotella intermedia have been shown to be a closely related species now known as Prevotella nigrescens. The purpose of this study was to determine the efficacy of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and polymerase chain reaction (PCR) to differentiate endodontic isolates of P. nigrescens from P. intermedia. Fifty-six strains of black-pigmented bacteria isolated from endodontic infections and conventionally identified as P. intermedia were used in this study. Using SDS-PAGE, novel polypeptide bands were used to differentiate P. nigrescens from P. intermedia. PCR was accomplished with specific primers for the 16S ribosomal RNA gene of both strains. Of 56 endodontic isolates, 41 (73%) strains were identified by SDS-PAGE as P. nigrescens and 15 (27%) strains as P. intermedia. Of the 41 strains of P. nigrescens identified by SDS-PAGE, PCR identified 37 strains as P. nigrescens. Restriction endonuclease digestion of amplified 16S ribosomal RNA genes indicated that the remaining four strains originally identified by SDS-PAGE as P. nigrescens were actually strains of Prevotella distinct from P. nigrescens and P. intermedia. Of 15 strains of P. intermedia identified by SDS-PAGE, PCR identified 14 strains as P. intermedia; but, one strain was identified as P. nigrescens. The results indicated that PCR was a more precise method than SDS-PAGE to differentiate P. intermedia from P. nigrescens. This study confirms that P. nigrescens is more commonly isolated in pure culture from endodontic infections than P. intermedia.

MR566A and MR566B, new melanin synthesis inhibitors produced by Trichoderma harzianum. I. Taxonomy, fermentation, isolation and biological activities.

New melanin synthesis inhibitors (MR566A and B) and six related known isocyanocyclopentenes were isolated from the fermentation broth of Trichoderma harzianum. The IC50 values of MR566A and B against mushroom tyrosinase were 1.72 and 47 microM, respectively. They inhibited melanin biosynthesis in B16 melanoma cells with MIC values of 0.1 and 2.2 microM, respectively. Also isolated from the same culture extract of T. harzianum was a new oxazole (MR93B), which showed no inhibitory activity against mushroom tyrosinase at a concentration of 1,000 microg/ml.

Chaetoatrosin A, a novel chitin synthase II inhibitor produced by Chaetomium atrobrunneum F449.

Chaetoatrosin A, a novel chitin synthase II inhibitor, was isolated from the culture broth of fungus F449, which was identified as Chaetomium atrobrunneum F449. Chaetoatrosin A was purified by solvent partition, silica gel, ODS, preparative TLC, and Sephadex LH-20 column chromatographies, consecutively. The structure of chaetoatrosin A was assigned as 1,8-dihydroxy-3(2-hydroxypropionyl)-6-methoxynaphthalene on the basis of various spectroscopic analyses including UV, IR, mass spectral, and NMR. Its molecular weight and formula were found to be 262 and C14H14O5, respectively. ,Chaetoatrosin A inhibited chitin synthase II by 50% at the concentration of 104 microg/ml in an enzyme assay system. This compound showed antifungal activities against Rhizoctonia solani, Pyricularia oryzae, Botrytis cinerea, Cryptococcus neoformans and Trichophyton mentagrophytes.