Zn-induced wipeout effect on Cu NQR spectra in La2−x_{2-x}Srx_xCu1−y_{1-y}Zny_yO4_4

We report a systematic study of Zn-substitution effect on Cu NQR spectrum for high $T_c$ superconductors La$_{2-x}$Sr$_x$Cu$_{1-y}$Zn$_y$O$_4$ from carrier-underdoped to -overdoped regimes (polycrystalline samples, $x$ =0.10, 0.15, and 0.20). We observed no appreciable wipeout effect for the overdoped samples, a gradual and partial wipeout effect below about 80 K for the optimally doped ones, and very abrupt and full wipeout effect below about 40 K for the underdoped ones. The wipeout effect indicates a highly enhanced spectral weight of Cu spin fluctuations at a low frequency. We associate the wipeout effect with a Zn-induced local magnetism far above 40 K and with a localization effect below 40 K.Comment: 2 pages, 3 figures, accepted for publication in Physica C (LT23, Hiroshima 2002

Helicobacter suis-Associated Gastritis Mimicking Conventional H. pylori-Associated Atrophic Gastritis

A 45-year-old Japanese man underwent esophagogastroduodenoscopy, which revealed spotty redness at the gastric fornix, mucosal swelling, diffuse redness in the corpus, and mucosal atrophy in the gastric angle and antrum. Histological examination showed rod-shaped bacteria that appeared larger than Helicobacter pylori. The patient tested positive for rapid urease test, and serum anti-H. pylori IgG antibody test results were negative. Further examination of the bacteria revealed that H. suis antibody test was positive, and the presence of H. suis was confirmed using H. suis-specific real-time PCR. H. suis was successfully eradicated after triple therapy with vonoprazan, amoxicillin, and clarithromycin. This case reinforces the notion that non-H. pylori Helicobacter species such as H. suis and H. heilmannii may be involved in the pathogenesis of active gastritis in patients who test negative for H. pylori antibodies