• Title/Summary/Keyword: proton pump

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Potassium-competitive acid blocker-associated gastric mucosal lesions

  • Kimitoshi Kubo;Noriko Kimura;Mototsugu Kato
    • Clinical Endoscopy
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    • v.57 no.4
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    • pp.417-423
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    • 2024
  • Since the introduction of vonoprazan, a potassium-competitive acid blocker (P-CAB), it has been demonstrated to reversibly inhibit gastric acid secretion by engaging in potassium-competitive ionic binding to H+/K+-ATPase. In contrast, proton pump inhibitors (PPIs) achieve H+/K+-ATPase inhibition through covalent binding to cysteine residues of the proton pump. Reported cases have indicated an emerging trend of P-CAB-related gastropathies, similar to those associated with PPIs, as well as unique gastropathies specific to P-CAB use, such as the identification of web-like mucus. Pathologically, parietal cell profusions, which show a positively correlated with hypergastrinemia, have a higher incidence in P-CAB users compared to PPI users. Thus, this review aims to summarize the endoscopic and pathological findings reported to date concerning P-CAB-related gastric mucosal lesions. Additionally, it seeks to discuss the differences between the PPIs and P-CABs in terms of the formation and frequency of associated gastropathies. This review highlights the evident differences in the mechanism of action and potency of acid inhibition between P-CABs and PPIs, notably contributing to differences in the formation and frequency of associated gastropathies. It emphasizes the necessity to distinguish between P-CAB-related and PPI-related gastropathies in the clinical setting.

PEFP CONTROL SYSTEM USING EPICS

  • Choi HyunMi;Hong In.Seok;Song YoungGi;Cho YongSub
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.656-658
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    • 2005
  • KAERI (Korea Atomic Energy Research Institute) has been performing the project named PEFP (proton engineering frontier project). PEFP has been performing the project of a high power proton accelerator. Control system for 20 MeV proton accelerating structure has developed. We use the EPICS(Experimental Physics and Industrial Control System) tool kit as a foundation of the control system. EPICS is adopted for control systems which have OPI(OPerator Interface) and IOqlnput Output Controller). We have performed the PEPF control system on SUN workstation host computer. In this paper, we present the vacuum monitor, RFQ, and DTL Turbo pump control system.

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Photochemical properties of a Rhodopsin for Light Energy Conversion obtained from Yellow Sea in Korea

  • Kim, So Young;Jung, Kwang-Hwan
    • Rapid Communication in Photoscience
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    • v.2 no.2
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    • pp.52-55
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    • 2013
  • Proteorhodopsin (PR) is a photoinduced proton pump found abundantly in ocean and fresh water habitat, and has an important role in photoenergy conversion to bioenergy in the living cells. Numerous sequences that encode PR protein variants were discovered by environmental genome sequencing and they indicated the high sequence similarity. A new-type of PR (YS-PR) which had been discovered from the surface of Yellow Sea was found to have only 5 amino acid differences from the previously known green-light absorbing PR (GPR) protein, but showed different photochemical properties. This YS-PR showed a 10 nm red-shifted absorption maximum, when compared with GPR. It also showed slower photocycling rate than GPR. However, the photoconversion rate of YS-PR was fast enough to pump protons. Four different amino acids out of 5 were similar to Blue-light absorbing PR (BPR), suggesting that those residues might be responsible for the observed spectral and photoconverting properties.

Cation Flux-Mediated Activation of P-Type ATPase in Helicobacter pylori

  • Yun, Soon-Kyu;Ki, Mi-Ran;Park, Jeong-Kyu;Lim, Wang-Jin;Hwang, Se-Young
    • Journal of Microbiology and Biotechnology
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    • v.10 no.4
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    • pp.441-448
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    • 2000
  • The production and cation flux-mediated activation of the P-type ATPase in Helicobacter pylori was investigated. Using the polymerase chain reaction (PCR), the proton pump genotype of H. pylori was found to be positive for both F-type and P-type ATPases. Yet, their production in terms of enzyme specific activity varied substantially depending on H. pylori strains, ranging over 3-fold. Its main constituent appeared to be the P-type ATPase pool, in contrast to other common bacterial compositions. Interestingly, the F-type ATPase was observed only when intact H. pyloricells were exposed to pH 4.5 or above (37$^{\circ}C$ for 1 h). In contrast, significant amounts of the P-type ATPase still remained after 1 h of cell treatment even at pH below 4.5. By enriching the acidic medium with RPMI(pH 3.0), the P-type ATPase was stabilized, accompained by inactivation of the F-type ATPase. Using H. pylori membrane vesicles, it was found that ammionia-mediated cation flux increased the rate of ATP hydrolysis by the P-type ATPase. Accordingly, these data strongly suggest that the P-type ATPase is involved or functions as an effective regulator for the cation flux across the H. pylori membrane, thereby reducing the risk of excess proton influx.

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X-ray Crystallographic Study of Archaerhodopsin

  • Enami, Nobuo;Okumura, Hideo;Kouyama, Tsutomu
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.320-322
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    • 2002
  • Archaerhodopsin (aR), a light-driven proton pump found in HaIonubrum sp. aus-l, was crystallized into an octahedral crystal belonging to the space group P4$_3$2$_1$2. It is shown that aR is composed of7 helical segments and an anti-para1leI ${\beta}$ sheet. The main-chain sIrudure of aR is nearly identical to that of bacteriorhodopsin, but a significant structural difference is observed in the protein surface, especially at lipid binding sites.

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Transport of Metal Ions Through the Crosslinked Chitosan Membrane (가교 Chitosan막에 의한 금속 이온의 투과 특성)

  • Kim, Chong-Bae
    • Applied Chemistry for Engineering
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    • v.4 no.2
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    • pp.416-422
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    • 1993
  • In order to prepare high performance polymeric membrane, the crosslinked chitosan(C. Chitosan)membrane was prepared, the transport and the selective separation of the metal ions through the membrane were investigated. It was observed that the transport rates of the metal ions through the membrane increased according to the decreasing of the initial pH in downstream solution. Proton pump mechanism for this transport phenomenon was suggested. The transport selectivity is dependent on the selective adsorption resulting from the complex formation of chitosan with each metal ion. The separatin factor(${\alpha}_{Cu}{^{2+}}$) for the membrane was 9.5.

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Dose-Independent Pharmacokinetics of a New Reversible Proton Pump Inhibitor, KR-60436, after Intravenous and Oral Administration to Rats: Gastrointestinal First-Pass Effect

  • Yu, Su-Yeon;Shin, Jee-Hyun;Bae, Soo-Kyung;Kim, Eun-Jung;Kim, Yoon-Gyoon;Kim, Sun-Ok;Lee, Dong-Ha;Lim, Hong;Lee, Myung-Gull
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.311.1-311.1
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    • 2003
  • Dose-independent pharmacokinetic parameters of KR-60436, a new proton pump inhibitor, were evaluated after an intravenous, iv (5, 10, and 20 mg/kg) and an oral (20, 50, and 100 mg/kg) administration to rats. The hepatic, gastric, and intestinal first-pass effects were also measured after iv, intraportal (ip), intragastric (ig), and intraduodenal (id) administration at a dose of 20 mg/kg to rats. (omitted)

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