Publications by authors named "Yumiko Nagano"

Gosha-jinki-gan (GJG) and Keishi-bukuryo-gan (KBG) are Kampo traditional herbal prescriptions used for different clinical patterns () that improve blood flow. The pharmacological basis of the therapeutic choice remains unclear, although the clinical reliance of this pattern-based therapy is widely proven. We aimed to investigate their effects on microcirculation and nitric oxide (NO) kinetics using a live-imaging system to provide evidence for this.

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Leukocyte activation and the resulting oxidative stress induced by bioincompatible materials during hemodialysis impact the prognosis of patients. Despite multiple advances in hemodialysis dialyzers, the prognosis of hemodialysis patients with complications deeply related to oxidative stress, such as diabetes mellitus, remains poor. Thus, we re-evaluated the effects of hemodialysis on multiple reactive oxygen species using electron spin resonance-based methods for further improvement of biocompatibility in hemodialysis.

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This case-control study aimed to assess oxidative stress alterations in autism spectrum disorder (ASD). We used the MULTIS method, an electron spin resonance-based technique measuring multiple free radical scavenging activities simultaneously, in combination with conventional oxidative stress markers to investigate the ability of this MULTIS approach as a non-behavioural diagnostic tool for children with ASD. Serum samples of 39 children with ASD and 58 age-matched children with typical development were analysed.

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Aim: To investigate the anticancer mechanisms of the monoterpenoid alcohol linalool in human colon cancer cells.

Methods: The cytotoxic effect of linalool on the human colon cancer cell lines and a human fibroblast cell line was examined using the WST-8 assay. The apoptosis-inducing effect of linalool was measured using the terminal deoxynucleotidyl transferase dUTP nick-end labeling assay and flow cytometry with Annexin V.

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Kangen-karyu, a prescription containing six herbs, has been shown to achieve its pharmacological effect through oxidative stress-dependent pathways in animal models. The aim of this study is to investigate the relationship between the antioxidative effect and pharmacological mechanisms of Kangen-karyu, specifically its body temperature elevating effect in humans. Healthy human volunteers, age 35 ± 15 years old, were enrolled in this study.

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Fridovich identified CuZnSOD in 1969 and manganese superoxide dismutase (MnSOD) in 1973, and proposed "the Superoxide Theory," which postulates that superoxide (O2 (•-)) is the origin of most reactive oxygen species (ROS) and that it undergoes a chain reaction in a cell, playing a central role in the ROS producing system. Increased oxidative stress on an organism causes damage to cells, the smallest constituent unit of an organism, which can lead to the onset of a variety of chronic diseases, such as Alzheimer's, Parkinson's, amyotrophic lateral sclerosis and other neurological diseases caused by abnormalities in biological defenses or increased intracellular reactive oxygen levels. Oxidative stress also plays a role in aging.

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Treatments with nonsteroidal anti-inflammatory drugs (NSAIDs) have increased the number of patients with gastrointestinal complications. Qing Dai has been traditionally used in Chinese herbal medicine for various inflammatory diseases such as ulcerative colitis. We previously reported that Qing Dai suppressed inflammations by scavenging reactive oxygen species (ROS) in ulcerative colitis patients.

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Bisphosphonates such as alendronate and risedronate are commonly used for the treatment of postmenopausal osteoporosis. They have the gastrointestinal adverse effects such as erosions and ulcers in stomach and small intestine. However, the detailed biological mechanism remains to be elucidated.

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Non-steroidal anti-inflammatory drugs (NSAIDs) often cause gastrointestinal complications such as gastric ulcers and erosions. Recent studies on the pathogenesis have revealed that NSAIDs induce lipid peroxidation in gastric epithelial cells by generating superoxide in mitochondria, independently with cyclooxygenase inhibition and the subsequent prostaglandin deficiency. More recently, gastric hydrochloric acid (HCl) has been regarded as an inciting factor of gastric mucosal injuries, and reportedly induced cellular lipid peroxidation in vitro.

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N(ε)-(Hexanoyl)lysine, formed by the reaction of lysine with n-6 lipid hydroperoxide, is a lipid peroxidation marker during the initial stage of oxidative stress. The aim of the present study is to indentify N(ε)-(hexanoyl)lysine-modified proteins in neoplastic transformed gastric mucosal cells by N-methyl-N'-nitro-N-nitrosoguanidine, and to compare the levels of these proteins between gastric mucosal cells and normal gastric cells. Much greater fluorescence of 2-[6-(4'-hydroxy)phenoxyl-3H-xanthen-3-on-9-yl]benzoic acid, an index of the intracellular levels of reactive oxygen species, was observed for gastric mucosal cells compared to normal gastric cells.

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Background: Gastric hydrochloric acid (HCl) has been regarded as an inciting factor in gastric mucosal injuries and has been reported to induce lipid peroxidation in vitro. However, because HCl is not an oxidant per se, the exact mechanism by which the acid induces lipid peroxidation is unknown. We hypothesized that gastric acid may disrupt mitochondrial transmembrane potential and induce the production of superoxide in mitochondria, which subsequently may induce lipid peroxidation and apoptosis in gastric mucosal cells.

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Lansoprazole is effective in healing non-steroidal anti-inflammatory drugs induced ulcers, and antioxidant properties have been thought to play a key role in healing ulcers. We hypothesize that lansoprazole exerts a cytoprotective effect by inhibiting reactive oxygen species leakage from mitochondria and lipid peroxidation. We pretreated gastric epithelial RGM1 cells with lansoprazole and then treated them with indomethacin in vitro.

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Non-steroidal anti-inflammatory drugs are the most commonly prescribed drugs for arthritis, inflammation, and cardiovascular protection. However, they cause gastrointestinal complications. The pathophysiology of these complications has mostly been ascribed to non-steroidal anti-inflammatory drugs' action on the cyclooxygenase inhibition and the subsequent prostaglandin deficiency.

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N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induces gastric cancer in animal models. We established an MNNG-induced mutant of the rat murine RGM-1 gastric epithelial cell line, which we named RGK-1, that could be used as an in vitro model of gastric cancer. This cell line showed signs of neoplasia and transformation, in that it lost contact inhibition and formed tumors in nude mice.

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Nonsteroidal antiinflammatory drugs (NSAIDs) cause complications such as gastrointestinal injury. NSAIDs were recently reported to cause mitochondrial injury: to dissipate the mitochondrial transmembrane potential (MTP), and to induce mitochondrial permeability transition pore (PTP), which liberates cytochrome c. This enzyme generates reactive oxygen species (ROS) thereby triggers caspase cascade and cellular lipid peroxidation, resulting in cellular apoptosis.

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Article Synopsis
  • The conformational properties of vasoactive intestinal peptide (VIP) include a crucial N-terminal randomized structure and a C-terminal long alpha-helical structure, both affecting its receptor selectivity.
  • VIP analogues were chemically synthesized and tested for their alpha-helical content and biological activities, revealing that the alpha-helix is significantly linked to their effectiveness in relaxing murine stomach and receptor binding.
  • Key findings indicate that the alpha-helical structure requires 14 specific amino acids in VIP, and disruptions in the mid-chain or N-terminus negatively impact biological functions, highlighting the importance of the C-terminal residues for alpha-helix formation.
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