Impurity Substitution Effect on Magnetoelectric Properties of CaBaCo4O7 Crystals

AbstractWe have investigated effects of impurity substitution of Fe for Co sites on magnetic and dielectric properties in CaBa(Co1-xFex)4O7 crystals in magnetic fields. The non-doped compound, CaBaCo4O7 with the polar space group Pbn21, shows a large change of electric polarization ΔP along the c axis below a ferrimagnetic transition temperature. With increasing x, the transition temperatures for the ferrimagnetic and ferroelectric-like phases are shifted towards lower and these phases are completely collapsed above x=1.56%. We have also investigated the magnetic field effects for CaBa(Co1-xFex)4O7 crystal with a doping level x=0.5% where the ferrimagnetic and ferroelectric-like phases sustain. Then a relatively large magnetocapacitance, Δɛ(H)/ɛ(0) [ɛ(H) – ɛ(0)]/ɛ(0), of 45% at 58K was observed, which is not significantly reduced from the parent compound

Predicting Therapeutic Effects using PET/CT

This study investigated the usefulness of [18F]-3’-deoxy-3’-fluorothymidine (18F-FLT) and [18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging for predicting the therapeutic efficacy of non-small cell lung cancer (NSCLC) irradiation at an early stage after radiation treatment. Mice were xenografted with the human lung adenocarcinoma line A549 or large cell lung cancer line FT821. Tumour uptake of 18F-FLT and 18F-FDG was imaged using PET/CT before and 1 week after irradiation. In A549 tumours, 18F-FLT uptake was significantly decreased, and 18F-FDG uptake was unchanged post-irradiation compared with pre-irradiation. In FT821 tumours, uptake of both 18F-FLT and 18F-FDG uptake was substantially decreased post-irradiation compared with pre-irradiation. In both xenografts, tumour volumes in the irradiated groups were significantly decreased compared with those in the control group. 18F-FLT is expected to contribute to individual NSCLC therapy because it accurately evaluates the decrease in tumour activity that cannot be captured by 18F-FDG. 18F-FDG may be useful for evaluating surviving cells without being affected by the inflammatory reaction at an extremely early stage, approximately 1 week after irradiation. Combined use of 18F-FLT and 18F-FDG PET/CT imaging may increase the accurate prediction of radiotherapy efficacy, which may lead to improved patient outcomes and minimally invasive personalised therapy

Role of unbalanced growth of Gram-negative bacteria in ileal ulcer formation in rats treated with a nonsteroidal antiinflammatory drug

Nonsteroidal anti-inflammatory drugs (NSAIDs) induced formation of intestinal ulcers as side effects, in which an unbalanced increase in the number of Gram-negative bacteria in the small intestine plays an important role. To clarify how intestinal microflora are influenced by NSAIDs, we examined the effects of 5-bromo-2-(4-fluorophenyl)-3-(4-methylsulfonylphenyl) thiophene (BFMeT), an NSAID, on intestinal motility and on the growth of Escherichia coli and Lactobacillus acidophilus. Transit index, a marker of peristalsis, was not different in BFMeT-treated and solvent-treated rats, indicating that BFMeT increased the number of Gram-negative bacteria without suppression of peristalsis. The factors that affect the growth of intestinal bacteria were not found in intestinal contents of BFMeT-treated rats, because the growth of E. coli and that of L. acidophilus in the supernatants of small intestinal contents of BFMeT-treated rats and solvent-treated rats were not different. The mechanism of the increase in the number of Gram-negative bacteria is still unclear, but heat-killed E. coli cells and their purified lipopolysaccharide (LPS) caused deterioration of BFMeT-induced ileal ulcers, while they could not cause the ulcers by themselves without the NSAID. Concentration of LPS and myeloperoxidase activity level were elevated correlatively in the intestinal mucosa of rats treated with LPS and BFMeT. These results suggest that an increase in the number of Gramnegative bacteria and their LPS in the mucosa induces activation of neutrophils together with the help of NSAID action and causes ulcer formation

Activation of 1-nitropyrene by nitroreductase increases the DNA adduct level and mutagenicity

1-Nitropyrene (1-NP) is a mutagenic nitro compound in the environment. We studied correlations between the mutagenicity of 1-NP for three strains of Salmonella typhimurium, the activity of bacterial nitroreductases and the amount of 1-NP-derived DNA adducts. Bacterial strains used in this study were S. typhimurium strains TA98, nitroreductase-less mutant TA98NR and YG1021 carrying a nitroreductase-producing plasmid. The mutagenicity of 1-NP was measured using the Ames assay, and the nitroreductase activities of these strains were assayed by quantification of 1-aminopyrene produced from 1-NP. The DNA adducts were measured by the 32P-postlabeling method. Among the three bacterial strains, strain YG1021 was the highest in mutagenicity of 1-NP, the nitroreductase activity and the DNA adduct level. However, S. typhimurium strain TA98NR had the lowest values of these three parameters. Nitroreductase activity, DNA adduct level and mutagenicity were strongly correlated with each other. These results indicate that bacterial nitroreductase plays an important role in forming the DNA adducts, and that the higher the adduct level the higher the level of mutagenicity

Porphyromonas gingivalis Outer Membrane Vesicles Stimulate Gingival Epithelial Cells to Induce Pro-Inflammatory Cytokines via the MAPK and STING Pathways

Porphyromonas gingivalis (Pg) is a keystone pathogen associated with chronic periodontitis and produces outer membrane vesicles (OMVs) that contain lipopolysaccharide (LPS), gingipains, and pathogen-derived DNA and RNA. Pg-OMVs are involved in the pathogenesis of periodontitis. Pg-OMV-activated pathways that induce the production of the pro-inflammatory cytokines, interleukin (IL)-6, and IL-8 in the human gingival epithelial cell line, OBA-9, were investigated. The role of mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB in levels of Pg-OMV-induced pro-inflammatory cytokines was investigated using Western blot analysis and specific pathway inhibitors. Pg-OMVs induced IL-6 and IL-8 production via the extracellular signal-regulated kinase (Erk) 1/2, c-Jun N-terminal kinase (JNK), p38 MAPK, and NF-κB signaling pathways in OBA-9 cells. In addition, the stimulator of interferon genes (STING), an essential innate immune signaling molecule, was triggered by a cytosolic pathogen DNA. Pg-OMV-induced IL-6 and IL-8 mRNA expression and production were significantly suppressed by STING-specific small interfering RNA. Taken together, these results demonstrated that Pg-OMV-activated Erk1/2, JNK, p38 MAPK, STING, and NF-κB signaling pathways resulting in increased IL-6 and IL-8 expression in human gingival epithelial cells. These results suggest that Pg-OMVs may play important roles in periodontitis exacerbation by stimulating various pathways

PCR-dot blot hybridization based on the neuraminidase-encoding gene is useful for detection of Bacteroides fragilis

Bacteroides fragilis is a Gram-negative obligate anaerobe frequently isolated from clinical specimens and sometimes causes severe septicemia in compromised hosts. Increasing interest has been shown in the enterotoxigenicity and drug resistance of B. fragilis in the field of medical microbiology. We previously reported rapid detection of this anaerobe by nested PCR targeting a neuraminidase-encoding gene nanH. In the present study, we synthesized a digoxigenin-labeled oligonucleotide probe, NH1,which is specific for nanH of B. fragilis, and we combined the hybridization assay using NH1with the nanH-PCR to detect this anaerobe in a bacteremia model mice. In the specificity test, the oligonucleotide probe, NH1, hybridized only to amplification products from B. fragilis. PCR-dot blot hybridization based on nanH enabled detection of cells of B. fragilis in blood samples even when the number was as low as 2x103colony-forming units/ml. These findings suggest that PCR-dot blot hybridization targeting nanH is a useful procedure for diagnosis of septicemia caused by B. fragilis when viable cells in blood cannot be detected by the traditional culture techniques

Association between Inter-atrial Septum Motion and Persistent Atrial Fibrillation Recurrence after Catheter Ablation

Article信州医学雑誌 69(4) : 189-201(2021)departmental bulletin pape

Inhibitory effects of asiatic acid and CPT-11 on growth of HT-29 cells

Asiatic acid is a pentacyclic triterpene contained inmedicinal plants. The cytotoxic effect of this compound and its augmentative effect on the anticancer drug irinotecan hydrochloride (CPT-11) were investigated in the human colon adenocarcinoma cell lineHT-29. Asiatic acid dose-dependently showed cytotoxicity in HT-29 cells. DNA fragmentation, annexin-positive apoptotic cells, andcaspase-3 activation were observed in a dose-dependent manner. Acaspase-3 inhibitor suppressed the DNA ladder formation in a concentration-dependent manner. Bcl-2 and Bcl-xL proteins were decreased by asiatic acid treatment. These results indicate that asiatic acid induced apoptosis inHT-29 cells viacaspase-3activation.Cytotoxic effectsof combined treatment with CPT-11 and asiatic acid on HT-29 cells were further examined. Simultaneous treatment or sequential exposure first to asiatic acid and then to CPT-11 showed an additive effect. Synergism was observed when cells were first exposed to CPT-11 and then to asiatic acid. These results suggest that asiatic acid can be used as an agent for increasing sensitivity of colon cancer cells to treatment with CPT-11 or as an agent for reducing adverse effects of CPT-11

Effects of fermented brown rice on the intestinal environments in healthy adult

Purpose : The aim of this study is to investigate the prebiotic effects of brown rice fermented by Aspergillus oryzae (FBRA) on the intestinal environment in vitro and in healthy adults. Methods : Fresh fecal slurries from six healthy adults were incubated with FBRA to confirm prebiotic potentials of FBRA. Another thirty-six healthy adults were randomly allocated to 2 groups for the clinical study. Subjects consumed 21.0 g/day of either FBRA or control food for 2 weeks, followed by a 12-week intermission and then 2-week ingestion vice versa. Main outcome measures were bifidobacterial numbers and organic acid concentration in feces. Sub outcome measures were fecal microbiota, fecal environments and bowel function. Results : Incubation of fecal slurries with FBRA in vitro resulted in increased organic acids with individual-specific patterns. Bifidobacterial numbers were increased during incubation. In the clinical study, all participants safely completed this study. FBRA had little effect on fecal number of bifidobacteria, concentrations of organic acids or putrefactive metabolites, fecal pH, or fecal microbiota. Conclusion : FBRA has the potentials as a prebiotic, however, we could not detect its effects on the intestinal environment in vivo. The results in a clinical study indicated that FBRA could be safely used for healthy adults

Antimutagenicity of Murdannia loriformis in the Salmonella mutation assay and its inhibitory effects on azoxymethaneinduced DNA methylation and aberrant crypt focus formation in male F344 rats

An 80% ethanol extract of Murdannia loriformis, a Thai medicinal plant, was examined for antimutagenic activity and cancer chemopreventive activity. In the Salmonella mutation assay, the extract showed antimutagenicity against 2-amino-3-methylimidazo [4,5-f]quinoline, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline, 2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, 2-amino-1,4-dimethyl- 5H-pyrido[4,3-b]indole, 3-amino-1-methyl-5H-pyrido[4,3-b]indole, 2-amino-6-methyldipyrido [1,2-a:3’,2’-d] imidazole, 2-aminodipyrido[1,2-a:3’,2’-d]imidazole, 2-aminoanthracene, 2-(2- furyl)-3-(5-nitro-2-furyl) acrylamide,N-methyl-N’-nitro-N-nitrosoguanidineandmethylazoxymethanol acetate and reduced their mutagenicities to 31.4～67.9% at the dose of 10mg/plate. However, it did not inhibit the mutagenicities of 2-amino-9H-pyrido[2,3-b]indole, 2-amino-3-methyl-9 H-pyrido[2,3-b]indole, benzo[a]pyrene,N-ethyl-N’-nitro-N-nitrosoguanidine and 1-nitropyrene. The extract itself showed no mutagenicity. The chemopreventive activity of M. loriformis was examined using azoxymethane (AOM)-induced aberrant crypt focus (ACF) formation in the colon of F344 rats. The extract at doses of 0.1-1.0 g/kg wt significantly inhibited ACF formation in the initiation stage (21-51%), although it wasmore effective at a lower dose. In the post-initiation stage, the extract also tended to inhibit ACF formation (12 -27%) and significantly decreased the number of larger ACFs that have more than 3 aberrant crypts per focus. The extract inhibited the formation of O6-methylguanine and N7-methylguanine in the colonic mucosa and muscular layers but not or increased in the liver. These results indicate that M. loriformis extract has antimutagenic activity toward variousknownmutagens and that it inhibits AOM-induced ACF formation both in the initiation and post-initiation stages in the rat colon