Publications by authors named "Ryo Yamagata"

Our previous study showed the intrinsic ability of descending noradrenergic neurons projecting from the locus coeruleus to the spinal dorsal horn (SDH) to suppress itch-related behaviors. Noradrenaline and α-adrenaline receptor (α-AR) agonist increase inhibitory synaptic inputs onto SDH interneurons expressing gastrin-releasing peptide receptors, which are essential for itch transmission. However, the contribution of α-ARs expressed in SDH inhibitory interneurons to itch-related behavior remains to be determined.

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Itch is defined as an unpleasant sensation that provokes a desire to scratch. Our understanding of neuronal circuits for itch information transmission and processing in the spinal dorsal horn (SDH) has progressively advanced following the identification of SDH neuron subsets that are crucial for scratching behavior in models of itch. However, little is known about the control of acute and chronic itch by descending signals from the brain to the SDH.

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Background: Chronic itch is a highly debilitating symptom among patients with inflammatory skin diseases. Recent studies have revealed that gastrin-releasing peptide (GRP) and its receptor (gastrin-releasing peptide receptor [GRPR]) in the spinal dorsal horn (SDH) play a central role in itch transmission.

Objective: We aimed to investigate whether GRP-GRPR signaling is altered in SDH neurons in a mouse model of chronic itch and to determine the potential mechanisms underlying these alterations.

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A 48-year-old man with colorectal cancer and right inguinal lymph node metastasis had previously undergone radiotherapy and chemotherapy (uracil/tegafur/leucovorin) after a colostomy in another hospital before being referred to us. Esophagogastroduodenoscopy (EGD) revealed the presence of a gastric metastatic lesion. After three courses of treatment with a modified regimen of leucovorin plus 5-fluorouracil plus oxaliplatin-6 (mFOLFOX6), EGD revealed that the gastric lesion had disappeared; computed tomography revealed that the size of the primary tumor and inguinal lymph node metastasis were markedly reduced.

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Objective: Cyclooxygenase-2 (COX-2) expression is increased in gastric cancer. We examined COX-2 expression in early stage gastric cancer and background mucosa to elucidate the role of COX-2 in gastric carcinogenesis.

Methods: Thirty-three early gastric cancers obtained from 30 patients infected with Helicobacter pylori were studied.

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