Publications by authors named "T Katsu"

Antimicrobial peptides that act by disrupting bacterial membranes are attractive agents for treating drug-resistant bacteria. This study investigates a membrane-disrupting peptide mimic made of a cyclic oligosaccharide cyclodextrin scaffold that can be chemically polyfunctionalized. An antibacterial functional group on the peptide was simplified to an alkylamino group that combines cationic and hydrophobic moieties, the former to interact with the anionic bacterial membrane and the latter with the membrane interior.

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Article Synopsis
  • Transportation of COVID-19 patients outside isolation rooms should be minimized to prevent disease spread.
  • A case study involves a 71-year-old man with COVID-19 pneumonia who needed veno-venous extracorporeal membrane oxygenation (VV-ECMO) therapy due to poor blood oxygen levels.
  • The procedure was successfully performed at the bedside using a portable X-ray system to accurately guide cannula placement, avoiding complications.
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A membrane-active antimicrobial peptide gramicidin S-like amphiphilic structure was prepared from cyclodextrin. The mimic was a cyclic oligomer composed of 6-amino-modified glucose 2,3-di--propanoates and it exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria, together with no resistance development and low haemolytic activity against red blood cells.

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The emergence of drug-resistant bacteria has led to the high demand for new antibiotics. In this report, we investigated membrane-active antimicrobial β-cyclodextrins. These contain seven amino-modified alkyl groups on a molecule, which act as functional moieties to permeabilize bacterial cell membranes.

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We analyzed the structure-activity relationship of porphyrins with the photoinactivation of membrane function in bacteria and erythrocytes. The porphyrins tested were protoporphyrin (PP), mesoporphyrin (MP), deuteroporphyrin (DP), hematoporphyrin (HP), coproporphyrin (CP) and uroporphyrin (UP), along with hematoporphyrin derivative (HPD) and photofrin (PF). These porphyrins dissipated membrane potential of Staphylococcus aureus cells depending on the degrees of respiratory inhibition and K+ leakage.

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