Publications by authors named "Nakamori H"

Upon epithelial barrier dysfunction, lipopolysaccharide (LPS) stimulates glucagon-like peptide-1 (GLP-1) secretion from enteroendocrine L cells by activating Toll-like receptor 4 (TLR4). Because GLP-1 accelerates peristalsis in the proximal colon, the present study aimed to explore whether LPS facilitates colonic peristalsis by stimulating L cell-derived GLP-1 release. In isolated segments of rat proximal colon that were serosally perfused with physiological salt solution and luminally perfused with 0.

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In the gastrointestinal tract, nitrergic inhibition of the arteriolar contractility has not been demonstrated. Here, we explored whether neurally-released nitric oxide (NO) inhibits sympathetic vasoconstrictions in the rat rectal arterioles. Changes in sympathetic vasoconstrictions and their nitrergic modulation in rats exposed to water avoidance stress (WAS, 10 days, 1 h per day) were also examined.

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In isolated segments of the rat proximal colon, the dopamine reuptake inhibitor GBR 12909 (GBR) causes a dilatation, while the D-like receptor antagonist SCH 23390 (SCH) induces a tonic constriction, suggesting that neurally released dopamine tonically stimulates enteric inhibitory efferent neurons. Here, the targets of the enteric dopaminergic neurons were investigated. Cannulated segments of rat proximal colon were bathed in physiological salt solution and luminally perfused with 0.

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A hybrid deformable x-ray mirror consisting of a mechanical bender and a bimorph deformable mirror has been developed to realize adaptive optical systems, such as zoom condenser optics, for synchrotron-radiation-based x-ray microscopy. In the developed system, both bending mechanisms comprehensively contribute to the formation of the target mirror shape and can narrow the role of piezoelectric actuators, thereby enabling a more stable operation. In this study, the behavior of the bimorph mirror under the clamped condition was investigated, and the sharing of the deformation amount for each bending mechanism was optimized to minimize the amplitude of the voltage distribution of the bimorph mirror.

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Glucagon-like peptide-1 (GLP-1), a well-known insulin secretagogue, is released from enteroendocrine L cells both luminally and basolaterally to exert different effects. Basolaterally released GLP-1 increases epithelial ion transport by activating CGRP-containing enteric afferent neurons. Although bath-applied GLP-1 reduced the contractility of colonic segments, GLP-1-induced stimulation of afferent neurons could also accelerate peristaltic contractions.

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Familial hypercholesterolemia (FH) and chronic kidney disease, especially end-stage renal disease (ESRD), are common and put patients at a high risk of developing atherosclerotic cardiovascular disease (ASCVD). ESRD concomitant with FH may further increase the risk of ASCVD. Achieving target levels of low-density lipoprotein cholesterol (LDL-C) is difficult owing to the limitations of statin administration due to its side effects in ESRD.

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Background: Constipation is commonly seen in patients with Parkinson's disease associated with a loss of dopaminergic neurons in both central and enteric nervous systems. However, the roles of enteric dopaminergic neurons in developing constipation remain to be elucidated. Here, we investigated the roles of enteric dopaminergic neurons in the generation of colonic peristalsis.

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We evaluated the adhesion, friction characteristics, durability against bodily acids, sterilization, cleaning, and anti-reflection performance of diamond-like carbon (DLC) coatings formed as a surface treatment of intracorporeal medical devices. The major coefficients of friction during intubation in a living body in all environments were lower with DLC coatings than with black chrome plating. DLC demonstrated an adhesion of approximately 24 N, which is eight times stronger than that of black chrome plating.

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The central nervous system is involved in regulation of defaecation. It is generally considered that supraspinal regions control the spinal defaecation centre. However, signal transmission from supraspinal regions to the spinal defaecation centre is still unclear.

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Article Synopsis
  • The study found that male and female rats respond differently to painful stimuli in the colorectum, with males showing increased colorectal motility when exposed to capsaicin, while females did not.
  • Researchers discovered that serotonin and dopamine neurons are primarily involved in male responses, enhancing motility, whereas females' responses are influenced by GABAergic neurons, which may inhibit this activation.
  • This research sheds light on the biological mechanisms behind sex differences in certain gastrointestinal disorders, like irritable bowel syndrome.
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A 65-year-old man was admitted to our institution with vomiting and right flank pain. Computed tomography (CT) imaging showed a 21-cm retroperitoneal multilocular cystic tumor which had been identified four years previously. It had increased from 17 to 21 cm.

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  • Researchers explored the roles of the locus coeruleus (LC) and A11 dopaminergic region in stimulating colorectal contractions and found that activating these brainstem nuclei enhanced defecation reflexes.
  • Stimulation of the LC and A11 increased colorectal pressure but only when a blocker for GABA receptors was used in the spinal cord.
  • The study concluded that these brain regions act as control centers for defecation, relying on specific receptors to facilitate their effects on colorectal motility.
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We describe the case of a patient with hyperammonemia owing to urinary tract infections. The patient, a 66-year-old-woman, was previously diagnosed with bilateral hydronephrosis. She was admitted to the emergency room with macrohematuria and bilateral lumbar pain, which persisted for 2 days.

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A 48-year-old man with a history of cerebral infarction presented with gross hematuria. The patient's limping accompanies twisting trunk on his walking. The diagnosis was right upper ureteral stone.

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A new synthetic method for [1]benzothieno[3,2- b][1]benzothiophene derivatives (BTBTs) was developed. The present method consists of iodocyclization of 1,2-bis(2-methylthiophenyl)ethynes and photolysis of 3-iodo-(2-methylthiophenyl)benzo[ b]thiophenes. With 1,2-bis(2-methylthiophenyl)ethynes treated with I/PhI(OAc) in CHCl at room temperature, selective cyclization at sulfur took place to give 3-iodo-(2-methylthiophenyl)benzo[ b]thiophenes in good yields.

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PZT (lead zirconate titanate)-glued bimorph deformable mirrors are widely used in hard X-ray regimes; however, they have not yet been used in soft X-ray regimes because they are less compatible for usage under high vacuum. In this study, we developed a glue-free bimorph deformable mirror, in which silver nano-particles were employed to bond PZT actuators to mirror substrates. Under an appropriate bonding condition, the bonding layer was confirmed to be uniform and the mirror's bending characteristics were demonstrated to be sufficiently stable; its gas emission rate was also shown to be acceptable.

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Article Synopsis
  • The study investigates how peristalsis in the esophagus is regulated, focusing on the striated muscle area, using an innovative method in anesthetized rats.
  • The researchers used a balloon-tipped catheter to induce peristalsis by inflating the balloon, establishing a relationship between the volume and speed of inflation and the effectiveness of inducing peristaltic motility.
  • Key findings reveal the importance of both inflation velocity and nitric oxide in initiating peristalsis, suggesting that factors like mucosal afferent fibers may modulate mechanosensor activity necessary for this process.
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We have developed the new hybrid adaptive X-ray mirror based on mechanical and piezo-driven deformation to realize precise shape controllability on a long-length mirror. The mechanical bender approximately provides the required ellipse, while the piezoelectric actuators attached to the mirror correct very small residual errors to satisfy the diffraction-limited condition. The mechanical bender significantly reduces the role of the piezoelectric actuator, resulting in the suppression of accuracy degradation due to the drift and/or junction effect of the piezoelectric actuators.

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Article Synopsis
  • The spinal defecation center's role in regulating defecation is not fully understood, but the study reveals that monoamines like norepinephrine, dopamine, and serotonin can induce contractions in the colorectum when injected.
  • Capsaicin, a noxious stimulus, was shown to trigger transient propulsive contractions in the colorectal region, and this effect could be inhibited by blocking specific neurotransmitter receptors in the spinal defecation center.
  • The findings suggest that harmful stimuli activate pathways that enhance colorectal motility, contributing to our understanding of how the body responds to discomfort in this area.
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  • The presence of a fecal pellet in the colorectum triggers coordinated contractions and relaxations to efficiently push the pellet out of the body.
  • Research using balloons to monitor rectal motility in anesthetized rats revealed that the presence of a balloon enhances motility toward the anus while inhibiting motions toward the mouth, indicating a local reflex mechanism.
  • Disruption of the enteric nervous system impaired this local reflex, suggesting that an intrinsic regulatory mechanism exists to optimize bowel movements, and its dysfunction may contribute to issues like post-inflammation dysmotility in the colorectum.
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Background: Arterial hypertrophy and interstitial fibrosis are important characteristics in kidneys of angiotensinogen-knockout (Atg ) mice. In these mice, which exhibit polyuria and hypotension, sympathetic nerve signaling is estimated to be compensatorily hyperactive. Furthermore, transforming growth factor (TGF)-β1 is overexpressed in mice kidneys.

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Article Synopsis
  • Colorectal motility is influenced by two brain and spinal cord defecation centers, with serotonin (5-HT) playing a crucial role in enhancing movement.
  • Stimulation of the medullary raphe nuclei initially did not improve motility; however, blocking GABA receptors allowed the stimulation to increase colorectal contractions.
  • Activation of the raphe nuclei enhances motility through pelvic nerves and 5-HT receptors in the lumbosacral spinal cord, highlighting the complex interaction between different neurotransmitters in regulating bowel function.
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Background: We previously reported that intrathecal injection of noradrenaline or dopamine causes enhancement of colorectal motility. As these monoamines are neurotransmitters of descending pain inhibitory pathways in the spinal cord, we hypothesized that serotonin, which is one of the neurotransmitters involved in descending pain inhibition, also influences the lumbosacral defecation center. Therefore, we examined whether serotonin acting on the spinal defecation center enhances colorectal motility.

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Central adenosine A1-receptor (A1AR)-mediated signals play a role in the induction of hibernation. We determined whether activation of the central A1AR enables rats to maintain normal sinus rhythm even after their body temperature has decreased to less than 20 °C. Intracerebroventricular injection of an adenosine A1 agonist, N6-cyclohexyladenosine (CHA), followed by cooling decreased the body temperature of rats to less than 20 °C.

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