CaCO₃ mineralization in polymer composites with cellulose nanocrystals providing a chiral nematic mesomorphic structure

CaCO₃ mineralization was carried out using cellulose nanocrystal (CNC)/polymer composites wherein a chiral nematic structure of CNC assembly was immobilized in advance via a polymerization process of the precursory aqueous CNC/vinyl monomer lyotropics (7–11 wt% CNC in feed). Two series of polymer composites were prepared: CNC/poly(2-hydroxyethyl methacrylate) (PHEMA) and CNC/poly(2-hydroxyethyl methacrylate-co-acrylic acid) (P(HEMA-co-AA), HEMA:AA = 95:5–70:30 in mol). The mineralization was allowed to proceed solely by soaking the composite films in a salt solution containing Ca²⁺ and HCO₃− under a low-basic condition (pH ≤ 9). Polymorphism of CaCO3 deposited inside the films was examined by X-ray diffractometry as a function of the soaking time (1–5 day) and also of the matrix composition. In the CNC/PHEMA series, the polymorphic form changed from amorphous calcium carbonate (ACC) (1-day soaking) to metastable crystalline vaterite (3-day soaking) and then to a mixture of vaterite and aragonite (5-day soaking). In the mineralization of the CNC/P(HEMA-co-AA) series, the formation of stable calcite was prominent besides minor appearance of vaterite. It was deduced that the mesofiller CNC and the AA unit in the vinyl polymer, both bearing an anionic group (-SO₃− or -COO−), contributed to capturing Ca²⁺ to facilitate the CaCO₃ deposition in the swollen film matrix. The pre-invested chiral nematic organization was kept in any of the mineralized films (dried); however, the helical pitch was appreciably reduced relative to that observed before the mineralization, attributable to the increase of ionic strength in the CNCs' surroundings accompanied by the wet process. Thermogravimetry showed that the mineralization definitely improved the thermal performance (heat/flame resistance) of the mesomorphic order-retaining CNC/polymer composites

カンゴギョウム シエン ヲ メザシテ

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Application of ozone ultrafine bubble water for cleaning and sterilizing the dialysis circuit

The dialysis circuit was washed by the ultrafine bubble (UFB) water and ozone UFB water and sodium hypochlorite aqueous solution. The effect of washing time, ozone concentration of UFB water, influence of UFB water on artificial dialysis equipment, etc. were investigated. The cleaning and sterilizing effect of ozone UFB water passed through the filter for artificial dialysis was verified. It was confirmed that there were no colony bacteria in the circuit which was washed by the ozone UFB water for 1 hour. Ozone UFB water has the same bactericidal effect as sodium hypochlorite. As an alternative of sodium hypochlorite, we are expecting its application to the cleaning and sterilization of ozone UFB water for dialysis circuit

Comprehensive Prospective Analysis of the Factors Contributing to Aspiration Pneumonia Following Endoscopic Submucosal Dissection in Patients with Early Gastric Neoplasms

Endoscopic submucosal dissection (ESD) has become the first-line treatment for early gastric neoplasms; however, a subset of patients treated by this method develop aspiration pneumonia. We conducted a comprehensive prospective analysis of the factors contributing to post-ESD aspiration pneumonia in early gastric neoplasms in this study, with special focus on whether pre-treatment oral care can prevent aspiration pneumonia. Sixty-one patients who underwent ESD for gastric neoplasms were randomly assigned to the oral care or control groups. ESD was performed under deep sedation. Of 60 patients whose data were available for analysis, 5 (8.3%) experienced pneumonia confirmed either by chest radiography or computed tomography. Although no difference in the rate of pneumonia was found between the control and oral care groups, the post-oral care bacteria count was significantly higher in the saliva of patients who developed pneumonia compared to those without pneumonia. In addition, the presence of vascular brain diseases and the dose of meperidine were also significantly associated with the occurrence of pneumonia. These results suggest that the number of oral bacteria as well as pre-existing vascular brain diseases and high-dose narcotics can affect the incidence of post-ESD pneumonia

Decreased serum pyridoxal levels in schizophrenia : meta-analysis and Mendelian randomization analysis

Background: Alterations in one-carbon metabolism have been associated with schizophrenia, and vitamin B6 is one of the key components in this pathway. Methods: We first conducted a case–control study of serum pyridoxal levels and schizophrenia in a large Japanese cohort (n = 1276). Subsequently, we conducted a meta-analysis of association studies (n = 2125). Second, we investigated whether rs4654748, which was identified in a genome-wide association study as a vitamin B6-related single nucleotide polymorphism, was genetically implicated in patients with schizophrenia in the Japanese population (n = 10 689). Finally, we assessed the effect of serum pyridoxal levels on schizophrenia risk using a Mendelian randomization (MR) approach. Results: Serum pyridoxal levels were significantly lower in patients with schizophrenia than in controls, not only in our cohort, but also in the pooled data set of the meta-analysis of association studies (standardized mean difference –0.48, 95% confidence interval [CI] –0.57 to –0.39, p = 9.8 × 10–24). We failed to find a significant association between rs4654748 and schizophrenia. Furthermore, an MR analysis failed to find a causal relationship between pyridoxal levels and schizophrenia risk (odds ratio 0.99, 95% CI 0.65–1.51, p = 0.96). Limitations: Food consumption and medications may have affected serum pyridoxal levels in our cross-sectional study. Sample size, number of instrumental variables and substantial heterogeneity among patients with schizophrenia are limitations of an MR analysis. Conclusion: We found decreased serum pyridoxal levels in patients with schizophrenia in this observational study. However, we failed to obtain data supporting a causal relationship between pyridoxal levels and schizophrenia risk using the MR approach

The role of IL-18 in the modulation of matrix metalloproteinases and migration of human natural killer (NK) cells

AbstractIn this study, we examined whether interleukin-18 (IL-18) affects natural killer (NK) cells' migration and matrix metalloproteinases (MMPs) production. We demonstrated that chemotaxis of human NK cells through basement membrane-like Matrigel was augmented by IL-18. As well, IL-18 stimulation induces the production of activated forms of matrix metalloproteinase-2 (MMP-2) as well as the production of pro-MMP-2 from NK cells. We also demonstrated that MT1-MMP expression on human NK cells, which is a major activator of MMP-2, was induced by IL-18 stimulation coordinated with MMP-2 activation. These data suggest that the MT1-MMP/MMP-2 system participates in the degradation of basement membrane components and thus contributes to NK cell migration

Mechanism of decrease of oral bioavailability of cyclosporin a during immunotherapy upon coadministration of amphotericin B

金沢大学附属病院薬剤部The trough level of blood concentration of cyclosporin A (CyA) in a patient receiving immunotherapy was observed to decrease following coadministration of amphotericin B (AMB). This clinical observation was confirmed experimentally in Wistar rats intravenously given AMB (1.5 or 3.0 mg/kg) or saline (control) for 4 days, followed by CyA (10 mg/kg). The blood concentration of CyA after i.v. or p.o. administration in both AMB groups was significantly decreased compared with the control. The oral bioavailability of CyA after 1.5 or 3.0 mg/kg AMB treatment was decreased to 67% or 46%, respectively, of that of the control group. AMB treatment increased the expression levels of mdr1a and mdr1b mRNAs in the duodenum to about three times the control, and expression of CYP3A2 mRNA in the liver was increased to about twice the control. The P-gp and CYP3A2 proteins were increased significantly. These findings suggest that the oral bioavailability of CyA is reduced as a result of both increased efflux transport via P-glycoprotein in the duodenum and an increased first-pass effect of CYP3A2-mediated hepatic metabolic activity, induced by AMB. It is suggested that careful monitoring of CyA levels is necessary in the event of AMB administration to patients receiving immunotherapy with CyA. Copyright © 2008 John Wiley & Sons, Ltd