Antibiofilm activity of irrigating solutions associated with cetrimide. Confocal laser scanning microscopy

AIM

To evaluate the antibiofilm activity of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) solutions associated with cetrimide (CTR), and QMiX using confocal laser scanning microscopy.

METHODOLOGY

Enterococcus faecalis (ATCC- 29212) biofilms were induced on bovine dentine blocks for 14 days. The dentine blocks containing biofilm were immersed for 1 min in the following solutions: 2.5% NaOCl; 2.5% NaOCl + 0.2% CTR; 2% CHX; 2% CHX + 0.2% CTR; 0.2% CTR; QMiX. After contact with the solutions, the dentine blocks were stained with Live/Dead(®) BacLight for analysis of the remaining biofilm using confocal laser scanning microscope. Images were evaluated using the BioImage_L software to determine the total biovolume (μm(3) ), the green biovolume (live cells) (μm(3) ) and the percentage of substrate coverage (%). The data were subjected to nonparametric statistical test using Kruskal-Wallis and Dunn's tests at 5% significance level.

RESULTS

After exposure to irrigants, the total biovolume observed for CHX, CHX+CTR, CTR, QMiX was similar to distilled water (P > 0.05). NaOCl and NaOCl+CTR had the lowest total and green biovolume. The CTR and QMiX had intermediate green biovolume, with greater antibacterial activity than CHX and CHX+CTR (P < 0.05). The NaOCl and NaOCl+CTR solutions were associated with microorganism removal and substrate cleaning ability.

CONCLUSIONS

NaOCl and NaOCl+CTR solutions were effective on microorganism viability and were able to eliminate biofilm. The addition of cetrimide did not influence antibacterial activity.

Comparison of the efficacy of sitagliptin and glimepiride dose-up in Japanese patients with type 2 diabetes poorly controlled by sitagliptin and glimepiride in combination

Aims/Introduction

The goal of the study was to examine the effects of sitagliptin dose‐up or glimepiride dose‐up in Japanese patients with type 2 diabetes who were controlled inadequately by sitagliptin and glimepiride in combination.

Materials and Methods

A multicenter, prospective, randomized, open‐label study was carried out in 50 patients with type 2 diabetes treated with sitagliptin and low‐dose glimepiride. The patients were randomly assigned to receive the addition of 50 mg/day sitagliptin or 0.5 mg/day glimepiride. The primary end‐point was the percentage change in glycated hemoglobin (HbA1c).

Results

During a follow‐up period, the difference in the percentage changes in HbA1c between the two groups was not significant (P = 0.13). However, HbA1c was significantly decreased by glimepiride dose‐up (P < 0.01 vs baseline), but not by sitagliptin dose‐up (P = 0.74). Univariate linear regression analyses showed that the percentage change in HbA1c was significantly associated with the serum level of arachidonic acid (AA) in both groups.

Conclusions

There was no significant difference in the HbA1c‐lowering effects between the two groups. However, a significant HbA1c‐lowering effect from baseline of glimepiride dose‐up was found, and the AA level showed a negative correlation with the decrease in HbA1c in the sitagliptin dose‐up group, but a positive correlation in the glimepiride dose‐up group. These findings suggest that the AA level is associated with HbA1c reduction in response to dose‐up with these drugs in patients with type 2 diabetes in a combination therapy with sitagliptin and glimepiride. This trial was registered with UMIN (no. 000009544).

Surgical technique to prevent spillage of cyst fluid during operation for cystic ovarian tumors

We describe a new technique to prevent spillage of cyst fluid in patients undergoing surgery for cystic ovarian tumors. The cyst is first covered with a sterilized surgical sheet applied with quick-drying glue and is then punctured. This technique completely prevents spillage of cyst fluid into abdominal cavity.

Effect of local anesthesia on trigeminal somatosensory-evoked magnetic fields

For objective neurophysiological evaluation of the function of the trigeminal system, magnetoencephalography- based TSEF (trigeminal somatosensory-evoked field) assessment would be valuable in providing spatial and temporal profiles of cortical responses. However, this necessitates knowledge of how TSEF varies with trigeminal nerve dysfunctions. We introduced a conduction block of the trigeminal nerve using local anesthesia (lidocaine) to temporally mimic nerve dysfunctions, and monitored TSEF changes. Following an electrical stimulation of the lower lip, a magnetic response with peak latency of approximately 20 ms was identified in all participants. Dipole for the peak was estimated on the post-central gyrus in the participant's own magnetic resonance image. After normalization to Montreal Neurological Institute (MNI) space and inter-participant data integration, the summary equivalent current dipole localization among participants remained in the post-central gyrus, suggesting validity of the use of MNI space. Partial anesthesia of the lower lip led to a loss of the waveform characteristics of TSEF for electrical stimulation to the trigeminal nerve. We verified that the 20-ms latency cortical response of TSEF components localized at the primary sensory cortex can serve as a robust neurofunctional marker of experimental trigeminal nerve dysfunction.

Outcomes after ischemic stroke for hospitals with and without Joint Commission-certified primary stroke centers

BACKGROUND

The Joint Commission (JC) began certifying primary stroke centers (PSCs) in the United States in 2003. We assessed whether 30-day risk-standardized mortality (RSMR) and readmission (RSRR) rates differed between hospitals with and without JC-certified PSCs in 2006.

METHODS

The study cohort included all fee-for-service Medicare beneficiaries ≥65 years old discharged with a primary diagnosis of ischemic stroke (International Classification of Diseases, ninth revision, Clinical Modification 433, 434, 436) in 2006. Hierarchical linear regression models calculated hospital-level RSMRs and RSRRs, adjusting for patient demographics, comorbid conditions, and hospital referral region. Hospitals were categorized as being higher than, no different from, or lower than the national average.

RESULTS

There were 310,381 ischemic stroke discharges from 315 JC-certified PSC and 4,231 noncertified hospitals. Mean overall 30-day RSMR and RSRR were 10.9% ± 1.7% and 12.5% ± 1.4%, respectively. The RSMRs of hospitals with JC-certified PSCs were lower than in noncertified hospitals (10.7% ± 1.7% vs 11.0% ± 1.7%), but the RSRRs were comparable (12.5% ± 1.3% vs 12.4% ± 1.7%). Almost half of JC-certified PSC hospitals had RSMRs lower than the national average compared with 19% of noncertified hospitals, but 13% of JC-certified PSC hospitals had lower RSRRs vs 15% of noncertified hospitals.

CONCLUSIONS

Hospitals with JC-certified PSCs had lower RSMRs compared with noncertified hospitals in 2006; however, differences were small. Readmission rates were similar between the 2 groups. PSC certification generally identified better-performing hospitals for mortality outcomes, but some hospitals with certified PSCs may have high RSMRs and RSRRs whereas some hospitals without PSCs have low rates. Unmeasured factors may contribute to this heterogeneity.

Production of extended single-layer graphene

Graphene has attracted an enormous amount of interest recently because of its unique electronic, optical, mechanical, and other properties. We report a promising method for producing single-layer graphene fully covering an entire substrate at low temperature. Single-layer graphene sheets have been synthesized on a whole 2 cm ×2 cm nickel (Ni) film deposited on a highly oriented pyrolytic graphite (HOPG) substrate by heating the Ni/HOPG in a vacuum. The carbon atoms forming our graphene are diffused from the graphite substrate through the nickel template. Our results demonstrate how to control the amount of carbon atoms for graphene formation to yield graphene films with a fine controlled thickness and crystal structure. Our method represents a significant step toward the scalable synthesis of high-quality graphene films with predefined thickness and toward realizing the unique properties of graphene films.

Fabrication of quantum-dot devices in graphene

We describe our recent experimental results on the fabrication of quantum-dot devices in a graphene-based two-dimensional system. Graphene samples were prepared by micromechanical cleavage of graphite crystals on a SiO₂/Si substrate. We performed micro-Raman spectroscopy measurements to determine the number of layers of graphene flakes during the device fabrication process. By applying a nanofabrication process to the identified graphene flakes, we prepared a double-quantum-dot device structure comprising two lateral quantum dots coupled in series. Measurements of low-temperature electrical transport show the device to be a series-coupled double-dot system with varied interdot tunnel coupling, the strength of which changes continuously and non-monotonically as a function of gate voltage.