Analgesic Mechanisms of Steroid Ointment against Oral Ulcerative Mucositis in a Rat Model

Despite the long history of use of steroid ointments for oral mucositis, the analgesic mechanism has not been fully elucidated. In this study, we examined the effects of triamcinolone acetonide (Tmc) on oral ulcerative mucositis-induced pain in conscious rats by our proprietary assay system. Based on evaluations of the physical properties and retention periods in the oral mucosa of human volunteers and rats, we selected TRAFUL^® ointment as a long-lasting base. In oral ulcerative mucositis model rats, TRAFUL^® with Tmc suppressed cyclooxygenase-dependent inflammatory responses with upregulations of glucocorticoid receptor-induced anti-inflammatory genes and inhibited spontaneous nociceptive behavior. When an ointment with a shorter residual period was used, the effects of Tmc were not elicited or were induced to a lesser extent. Importantly, TRAFUL^® with Tmc also improved oral ulcerative mucositis-induced mechanical allodynia, which has been reported to be independent of cyclooxygenase. Ca²⁺ imaging in dissociated trigeminal ganglion neurons showed that long-term preincubation with Tmc inhibited the hypertonic stimulation-induced Ca²⁺ response. These results suggest that the representative steroid Tmc suppresses oral ulcerative mucositis-induced pain by general anti-inflammatory actions and inhibits mechanical sensitivity in peripheral nerves. For drug delivery, long-lasting ointments such as TRAFUL^® are needed to sufficiently induce the therapeutic effects.     

Structural interpretation of plasma-polymerized propargyl alcohol

Vapor of propargyl alcohol under reduced pressure was glow-discharged for plasma polymerization by which hydrophilic polymer film could be deposited onto a solid substrate. The hydrophilic property was more enhanced with use of the same monomer containing water. An interpretation of chemical structures of the polymer molecules was therefore attempted to discover the reason of the hydrophilic property. The polymer materials were subjected to IR spectroscopy, ¹³C-NMR and ¹H-NMR spectroscopies, elemental analysis, number average molecular weight determination, mass spectrometry, and other wet chemical analysis for . The IR spectra of the polymers showed the presence of OH, C?O, and C?C groups with a disappearance of C?C group of the monomer. It was also found that the molecular formula of a solvent extract of the polymer derived from the plain monomer was C₂₆H₃₆O₉ ≒ 490, involving four hydroxyl, one carbonyl, and two to three olefinic unsaturation groups within a unit molecule. On the other hand, the polymer from 60% water-containing monomer showed its molecular formula as C₄₄H₆₆O₁₈ ≒ 890, containing seven to eight hydroxyl, two carbonyl, and one to two olefinic unsaturation groups. This information was used to establish the symbolic chemical structures of the polymer molecules. It has been found that both polymers were not as much crosslinked as other plasma polymers because of having side chains with fewer branching. The oxygen atoms were retained in the polymer not only as the forms of OH and C?O but also as a member of the principal frame of the polymers.     

Timer-based composition of fault-containing self-stabilizing protocols

One of the desired properties of distributed systems is self-adaptability against faults. Self-stabilizing protocols provide autonomous recovery from any finite number of transient faults. However, in practice, catastrophic faults rarely occur, while small-scale faults are more likely to occur. Fault-containing self-stabilizing protocols promise not only self-stabilization but also containment of the effect of small-scale faults, i.e., they promise quick recovery and small effect for small-scale faults. Hierarchical composition of self-stabilizing protocols is expected to ease the design of new self-stabilizing protocols. However, existing composition techniques for self-stabilizing protocols cannot preserve the fault-containment property of source protocols. In this paper, we propose a novel timer-based hierarchical composition of fault-containing self-stabilizing protocols that preserves the fault-containment property of source protocols. To implement timers, we propose a local neighborhood synchronizer that synchronizes limited number of processes during a short time after a fault without involving the entire network into the synchronization. The proposed composition technique facilitates the design of new fault-containing self-stabilizing protocols and enhances the reusability of existing fault-containing self-stabilizing protocols.     

Free-standing,roll-able,and transparent silicone polymer film prepared by using nanoparticles as cross-linking agents

A free-standing, roll-able, and transparent silicone-based polymer film with a tensile modulus of ca. 7.8 MPa and strain at the break point of 0.76% was successfully prepared by reaction between a reactive silicone oligomer with methyl- and methoxy-side groups and hydrophilic SiO₂ nanoparticles. First, SiO₂ nanoparticles were grafted with silicone chains by a controlled wet chemical sol–gel-type reaction with the reactive oligomers. The solvent of the resulting solution was evaporated to form a viscous suspension, casted into a film, and finally heat-treated at 100 °C and 150 °C. A hydrolysis and condensation reaction among silicone-grafted SiO₂ nanoparticles and free silicone oligomers in the final heat treatment resulted to produce free-standing, roll-able, and transparent silicone-based polymer film. The fact that the silicone film cannot be synthesized without the presence of SiO₂ nanoparticles suggests that these nanoparticles act as cross-linking agents of silicone components providing the improved mechanical properties to the composite film. The rate-controlled mixing and heating of the SiO₂ aqueous/alcohol suspension and the silicone oligomer/alcohol solution was found to be the key step in the synthesis of the free-standing transparent film. While rapid addition/mixing resulted in a fragile and opaque film, a transparent material was achieved when those solutions were slowly mixed. The effect of the synthesis process on the macroscopic and microscopic properties of the prepared films is discussed along with their formation mechanism.     

Elution of sodium caseinate from agar-based gel matrixes in simulated gastric fluids

Elution of sodium caseinate from agar/psyllium composite gels was investigated in simulated gastric fluids to determine predominant mechanical parameters of gels for the elution kinetics and to predict the kinetics using the parameters. When the concentration of agar was fixed at 0.5% in the composite gels, elastic moduli determined by creep tests decreased with increasing concentration of psyllium, while viscosities increased. Compression load upon syringing through an enteral tube increased with increasing concentration of psyllium, whereas the surface-volume diameter d_3,2 of gel particles after syringing decreased. The elution kinetics of sodium caseinate from cylindrical gels was described using two different diffusion coefficients; D₁ and D₂ (D₁ > D₂) and the diameter of gels. Both diffusion coefficients decreased with increasing concentration of psyllium, resulting in 1.9 × 10⁻⁶ (for D₁) and 6.7 × 10⁻⁸ (for D₂) cm²/min by 1.5% addition, which corresponded to approx. 30% and 45% of the control (i.e., 0% psyllium), respectively. The fraction ratio of sodium caseinate having D₁ was not sensitive to psyllium concentration; approx. 80%–85% in the concentration range tested. D₁ was inversely proportional to viscosities determined by creep tests, particularly one from the Voigt body η₁ in the 4-element mechanical model. When cube gels were divided into smaller ones without changing the total volume, elution rates were inversely proportional to the cube length, where the diffusion coefficients did not change. The elution kinetics of sodium caseinate from the gel matrixes was anticipated using η₁ of gels before syringing and d_3,2 of gel particles after syringing when the usage of gels for percutaneous endoscopic gastrostomy is assumed.