X-ray diffraction analysis of mineral trioxide aggregate and Portland cement

AIM: To compare the major constituents present in ProRoot mineral trioxide aggregate (MTA), ProRoot MTA (tooth coloured formula), ordinary Portland cement and white Portland cement using powder X-ray diffractometery. METHODOLOGY: X-ray diffractometery of the four materials was carried out with the divergence and scatter slits set at 1 degree and the receiving slit at 0.10 mm. The scan range was set at 5-70 degrees and continuous scans for the theta-2theta range were run with a scan speed of 2 degrees min(-1). The patterns obtained were then compared with the Powder Diffraction Files (PDF) found in the International Centre for Diffraction Data database. The three strongest peaks were used for the identification of the constituents. The relative intensities were plotted against the angle 2theta and compared with the plots in the PDF. RESULTS: The main constituents were found to be tricalcium silicate, tricalcium aluminate, calcium silicate, and tetracalcium aluminoferrite in all the four cements with the additional presence of Bi2O3 in ProRoot MTA and ProRoot MTA (tooth coloured formula). CONCLUSIONS: The four cements had similar major constituents. Data on Portland cement may be used for the further development or modification of ProRoot MTA in order to improve its physical characteristics and expand its scope of clinical applications.     

Early induction of calpains in rotenone-mediated neuronal apoptosis

Rotenone is an inhibitor of mitochondrial complex I that produces a model of Parkinson's disease (PD), where neurons undergo apoptosis by caspase-dependent and/or caspase-independent pathways. Inhibition of calpains has recently been shown to attenuate neuronal apoptosis. This study aims to establish for the first time, the time-point of calpain activation with respect to the caspase activation and the possibility of cell cycle re-entry in rotenone-mediated cell death. Immunoblot results revealed calpain activation occurred at 5, 10h prior to caspase-3 activation (at 15 h), suggesting calpain activation was an earlier cellular event compared to caspase activation in the rotenone-mediated apoptosis. In addition, an upregulation of phospho-p53 was observed at 21 h. However, no expression or upregulation of cell cycle regulatory proteins including cdc25a, cyclin-D1 and cyclin-D3 were observed, strongly suggesting that cell cycle re-entry did not occur. These findings provide new insights into the differential patterns of calpain and caspase activation that result from rotenone poisoning and which may be relevant to the therapeutic management of PD.     

Association of SLC6A12 variants with aspirin‐intolerant asthma in a Korean population

Aspirin‐intolerant asthma (AIA) occurs from asthma exacerbation after exposure to aspirin. However, the underlying mechanisms of AIA occurrence are still unclear. The critical role of the solute carrier family 6 (neurotransmitter transporter, betaine/GABA) member 12 (SLC6A12) gene in GABAergic transmission, which is associated with mucus production in asthma, makes it a candidate gene for AIA association study. Eight single nucleotide polymorphisms (SNPs) in SLC6A12 were genotyped in 163 aspirin‐intolerant asthma (AIA) and 429 aspirin‐tolerant asthma (ATA) patients of Korean ethnicity. Associations between polymorphisms of SLC6A12 and AIA were analysed using multivariate logistic analysis. Results showed that two polymorphisms and a haplotype in SLC6A12, rs499368 (P= 0.005; P^corr= 0.03), rs557881 (non‐synonymous C10R, P= 0.007; P^corr= 0.04), and SLC6A12_BL1_ht1 (P= 0.009; P^corr= 0.05) respectively, were significantly associated with AIA after multiple testing corrections. In addition, SNPs of SLC6A12 were significantly associated with the fall rate of FEV₁ by aspirin provocation suggesting that SLC6A12 could affect reversibility of lung function abnormalities in AIA patients. Although these results are preliminary and future replications are needed to confirm these findings, this study showed evidence of association between variants in SLC6A12 and AIA occurrence among asthmatics in a Korean population.     

Rate of isolation and trends of antimicrobial resistance of multidrug resistant pseudomonas aeruginosa from otorrhea in chronic suppurative otitis media

Objectives

To assess the rate of isolation of Pseudomonas aeruginosa (PA) and multidrug-resistant PA (MDR-PA) from patients with chronic suppurative otitis media (CSOM) otorrhea and the annual trend of antibiotic-resistance.

Methods

Otorrhea samples were collected aseptically from 1,598 CSOM patients. The rate of bacterial isolation and the results of antibiotic susceptibility testing were evaluated retrospectively.

Results

The PA isolation rate from CSOM otorrhea was 24.4%. Of the 398 isolated strains tested for their susceptibilities to 10 antibiotics, 395 strains showed definitive results. Of these, 183 (46.3%) were susceptible to whole antibiotics and 212 (53.7%) was resistant to more than 1 antibiotics, with the frequency of antibiotics-resistance increasing significantly over time. Although strains susceptible to all antibiotics decreased over time, the rate of isolation of MDR-PA did not change significantly. Resistance to aminoglycosides and quinolones was higher than to other antibiotics and significantly increased over time, whereas resistance to other antibiotics showed no trend.

Conclusion

MDR-PA, assessed using five individual antibiotics and six antibiotic-classes, showed no tendency to increase or decrease over time. This may have been due to increased concern about antibiotic-resistant bacterial strains, leading to improved infection control within hospitals and healthcare centers.     

Effect of NF‐κB Decoy Oligodeoxynucleotide on LPS/High‐Fat Diet‐Induced Atherosclerosis in an Animal Model

Abstract: Atherosclerosis is a chronic inflammatory process occurring in the walls of arteries, in large part due to the accumulation of inflammatory cells. This study was conducted to determine the effect of nuclear factor (NF)‐κB decoy oligodeoxynucleotide (ODN) in an atherosclerosis animal model. The mice received i.p. injections of lipopolysaccharide (LPS, 2 mg/kg) three times a week to induce atherosclerotic change, and fed an atherogenic diet for 12 weeks. NF‐κB decoy ODN (0.4 mg/kg) was injected into the tail vein. Treatment with NF‐κB decoy ODN decreased pro‐inflammatory cytokines, tumour necrosis factor (TNF)‐α and interleukin (IL)‐1β and inflammatory markers, vascular adhesion molecule (VCAM)‐1 and intercellular adhesion molecule (ICAM)‐1, in the LPS/Fat‐induced mice. In addition, the expression of proteins related to fibrosis, transforming growth factor (TGF)‐β1 and fibronectin were markedly decreased in the mice treated with NF‐κB decoy ODN compared with the LPS/Fat‐induced mice without decoy ODN treatment. These data suggest that NF‐κB decoy ODN may exert an inhibitory effect on the expression levels of pro‐inflammatory cytokines and cell adhesion molecules in atherosclerotic mice.