Identification of a locus involved in the utilization of iron by Actinobacillus pleuropneumoniae

The cloned afu locus of Actinobacillus pleuropneumoniae restored the ability of an Escherichia coli K-12 mutant (aroB) to grow on iron-limited media. DNA sequence analysis of the fragment showed that there are three genes designated afuA, afuB and afuC (Actinobacillus ferric uptake) that encode products similar to the SfuABC proteins of Serratia marcescens, the HitABC proteins of Haemophilia influenzae, the FbpABC proteins of Neisseria gonorrhoeae and the YfuABC proteins of Yersinia enterocolitica. The three genes encode a periplasmic iron-binding protein (AfuA), a highly hydrophobic integral cytoplasmic membrane protein with two consensus permease motifs (AfuB) and one hydrophilic peripheral cytoplasmic membrane protein with Walker ATP-binding motifs (AfuC), respectively. This system has been shown to constitute a periplasmic binding protein-dependent iron transport system in these organisms. The afuABC operon is locating approximately 200 bp upstream of apxIC gene, but transcribed in opposite direction to the ApxI-toxin gene

Clinical application of platelet-rich fibrin as the sole grafting material in periodontal intrabony defects

AbstractBackground/purposePlatelet-rich fibrin (PRF) obtained by Choukroun’s technique is a healing biomaterial that concentrates in a single autologous fibrin membrane, mostly of platelets and cytokines from blood harvest, and without any artificial biochemical modification. However, no data are presently available concerning the use of PRF for the treatment of periodontal intrabony defects. This report was to present the clinical and radiographic changes of a patient with periodontal intrabony defects treated with PRF.Material and methodsThe left mandibular first molar (#36) and left maxillary second molar (#27) with intrabony defects were filled with PRF as the sole grafting material in a 38-year-old female patient. The primary outcomes evaluated in this study included changes in probing depth, attachment level, and radiographic bone density between baseline and 6 months postoperatively.ResultsThe results showed that the application of PRF as the sole grafting material in intrabony defects exhibited pocket reduction and gain in clinical attachment after 3 months and 6 months. Using National institute of health program, the 6 months postoperative radiographic density of images for #27 and #36 showed an increase of 1.6 and 1.3 fold compared with each preoperative radiography, respectively.ConclusionsFrom a clinical and radiologic point of view at 6 months after surgery, the use of PRF as the sole grafting material seems to be an effective modality of regenerative treatment for periodontal intrabony defects

Tissue-engineered constructs for urethral regeneration

AbstractThose who have urethral injury, long-distance urethral stricture, hypospadias, or epispadias need tissue for urethral repair. Tissue engineering is one of the solutions for urethroplasty. Three components essential for tissue engineering are cells, scaffolds, and bioactive factors. Several animal studies of tissue-engineered urethras have been conducted and progressed to human clinical trials by 1999. These studies have shown that the maximum distance for normal tissue regeneration in tubularized urethral replacement with unseeded matrices is 0.5cm. Although autologous tissue-engineered tabularized urethras have been successful in clinical trials, this method could be an alternative treatment for urethral reconstruction

Effects of natto extract on endothelial injury in a rat model

Vascular endothelial damage has been found to be associated with thrombus formation, which is considered to be a risk factor for cardiovascular disease. A diet of natto leads to a low prevalence of cardiovascular disease. The aim of the present study was to investigate the effects of natto extract on vascular endothelia damage with exposure to laser irradiation. Endothelial damage both in vitro and in vivo was induced by irradiation of rose bengal using a DPSS green laser. Cell viability was determined by MTS assay, and the intimal thickening was verified by a histological approach. The antioxidant content of natto extract was determined for the free radical scavenging activity. Endothelial cells were injured in the presence of rose bengal irradiated in a dose-dependent manner. Natto extract exhibits high levels of antioxidant activity compared with purified natto kinase. Apoptosis of laser-injured endothelial cells was significantly reduced in the presence of natto extract. Both the natto extract and natto kinase suppressed intimal thickening in rats with endothelial injury. The present findings suggest that natto extract suppresses vessel thickening as a synergic effect attributed to its antioxidant and anti-apoptosis properties

Toward multi-target self-organizing pursuit in a partially observable Markov game

The multiple-target self-organizing pursuit (SOP) problem has wide applications and has been considered a challenging self-organization game for distributed systems, in which intelligent agents cooperatively pursue multiple dynamic targets with partial observations. This work proposes a framework for decentralized multi-agent systems to improve intelligent agents' search and pursuit capabilities. We model a self-organizing system as a partially observable Markov game (POMG) with the features of decentralization, partial observation, and noncommunication. The proposed distributed algorithm: fuzzy self-organizing cooperative coevolution (FSC2) is then leveraged to resolve the three challenges in multi-target SOP: distributed self-organizing search (SOS), distributed task allocation, and distributed single-target pursuit. FSC2 includes a coordinated multi-agent deep reinforcement learning method that enables homogeneous agents to learn natural SOS patterns. Additionally, we propose a fuzzy-based distributed task allocation method, which locally decomposes multi-target SOP into several single-target pursuit problems. The cooperative coevolution principle is employed to coordinate distributed pursuers for each single-target pursuit problem. Therefore, the uncertainties of inherent partial observation and distributed decision-making in the POMG can be alleviated. The experimental results demonstrate that distributed noncommunicating multi-agent coordination with partial observations in all three subtasks are effective, and 2048 FSC2 agents can perform efficient multi-target SOP with almost 100% capture rates

Fabrication of multianalyte CeO2 nanograin electrolyte–insulator–semiconductor biosensors by using CF4 plasma treatment

Multianalyte CeO2 biosensors have been demonstrated to detect pH, glucose, and urine concentrations. To enhance the multianalyte sensing capability of these biosensors, CF4 plasma treatment was applied to create nanograin structures on the CeO2 membrane surface and thereby increase the contact surface area. Multiple material analyses indicated that crystallization or grainization caused by the incorporation of flourine atoms during plasma treatment might be related to the formation of the nanograins. Because of the changes in surface morphology and crystalline structures, the multianalyte sensing performance was considerably enhanced. Multianalyte CeO2 nanograin electrolyte–insulator–semiconductor biosensors exhibit potential for use in future biomedical sensing device applications