212 research outputs found

    Singlet-triplet Crossover in the Two-dimensional Dimer Spin System YbAl3C3

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    Low-temperature magnetization (M) measurements down to 0.1 K have been performed in magnetic fields up to 14.5 T for a single piece of a tiny single-crystalline sample (0.2 mg weight) of the spin-gap system YbAl3C3. At the base temperature of 0.1 K, several metamagnetic transitions were clearly observed for H // c in the range 6 T < H < 9 T whereas only two transitions were observed, one at 4.8 T and the other at 6.6 T, for H // a. At fields above 9 T, the magnetization becomes almost saturated for both H // a and H // c. The present results indicate that a singlet-triplet crossover occurs in a relatively narrow field range, suggesting a rather weak interdimer interaction in spite of the nearly triangular lattice of Yb ions.Comment: 5 pages, 6 figures, proceedings of ICM 201

    Epidemiological ins and outs of helicobacter pylori: A review

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    Helicobacter pylori infection is now recognised as a worldwide problem. It is the most common cause of chronic gastritis, and is strongly linked to peptic ulcer disease and gastric cancer. A comprehensive understanding of epidemiological ins and outs of H. pylori infection is very important in solving the patho-physiological enigma and might help in leading towards better management and prognosis of infection. This article presents a review of the literature on the epidemiology of H. pylori infection from 2006 to 2011. The authors used Medical Subject Heading (MeSH) terms \u27Helicobacter\u27 with \u27epidemiology,\u27 \u27transmission\u27 or \u27risk factor\u27 to search PubMed database. All relevant studies identified were included. Despite extensive medical advancement, many questions on Helicobacter pylori epidemiology still remain unanswered. Further studies are, therefore, required to gain a better understanding of the transmission pathway of this notorious pathogen

    High-Magnetic-Field Studies of the Kondo Semiconductor CeNiSn(Transport and Fermiology)

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    The Kondo-lattice compound CeNiSn behaves as a narrow-gap semiconductor at low temperatures below 7 K. The effect of magnetic field on the gapped state of this compound has been studied by the measurements of magnetization, magnetoresistance and specific heat on a single-crystalline sample. A weak metamagnetic transition and very large negative magnetoresiostance are observed only when a magnetic field higher than 13 T is applied along the α axis of the orthorhombic structure. These results show that the pseudogap is suppressed anisotropically by the magnetic field. The collapse of the gap is accompanied with the evolution of a polarized heavy-fermion state

    Effect of COVID-19 vaccination on viral clearance and antibody production in older patients with SARS-CoV-2 infection

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    Whether coronavirus disease 2019 (COVID-19) vaccination promotes viral clearance in older patients has not been reported. We performed a retrospective review of patients hospitalized with COVID-19. This study included 24 patients with COVID-19 admitted to Hiroshima City Funairi Citizens Hospital between June 1 and July 10, 2021. Nine patients who were vaccinated (median age: 72 years) were compared with 15 patients who were not vaccinated (median age: 70 years). Viral clearance was confirmed by SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR). Antibody titers were measured to assess vaccination efficacy. The vaccinated group had a higher negative conversion rate than that in the non-vaccinated group on RT-PCR testing before discharge (83% vs. 36%, P = 0.064). Antibody titers on admission and 10 ± 2 days after onset were significantly higher in the vaccinated group than those in the non-vaccinated group (35 vs. 0 binding antibody units (BAU)/mL, P = 0.012; and 114 vs. 7 BAU/mL, P = 0.032, respectively). Stimulating antibody production by vaccination may promote faster viral clearance in older patients who develop COVID-19.This research was funded by “Advanced study aim to contribute creating new evidence in COVID-19 based on the local government-academia collaboration research system in Hiroshima”: AMED Research Program on Emerging and Re-emerging Infectious Diseases, Grant Number JP20fk0108453

    Anti-Helicobacter pylori activity and inhibition of Helicobacter pylori-induced release of IL-8 in AGS cells by plant extracts

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    Plants used in popular diet were studied for anti-Helicobacter pylori activity and their effect on the expression of interleukin-8 (IL-8) from H. pylori infected gastric epithelial cells. Extracts were prepared of Allium sativum (A. sativum), Cuminum cyminum (C. cyminum),Piper nigrum (P. nigrum) and their mix in two different dilutions. AGS cell line and H. pyloristrains were used for co-culture experiments. Extracts bactericidal activity was determined by a viable colony count. ELISA (Enzyme linked immunosorbent assay) was used to determine IL-8 expression. DNA extracted from bacterial cells was used for polymerase chain reaction (PCR) of cytotoxin-associated gene (cagA) and E (cagE). Results revealedH. pylori strains sensitivity to A. sativum (5.5 mg/ml) was 57% (39/69) (p=0.06), and to 11 mg/ml was 65% (45/69) (p=0.02) compared to amoxicillin, respectively. CagE positive H. pylori, 37% (11/30) (p=0.02) were sensitive to plant mixture (23.5 mg/ml), 60% (18/30) (pC. cyminum (PP. nigrum (P=0.0046) and A. sativum(P=0.0021), respectively compared to positive and negative controls. Thus, dietary plants demonstrated an anti-H. pylori effect. They reduced IL-8 expression from the H. pyloriinfected AGS cells. Key words: Helicobacter pylori; Allium sativum, Cuminum cyminum, Piper nigrum, gastric epithelial cells, interleukin-8, ELISA, cagA, cagE

    A case of small cell gastric carcinoma with an adenocarcinoma component operated curatively.

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    We present a case of a primary advanced gastric tumor that was composed of 2 different pathological components: small cell carcinoma and moderately-differentiated adenocarcinoma. The patient was still alive four years after the surgery was performed, without recurrence. A large part of the tumor consisted of a diffuse sheet of small cell carcinoma, which transitioned into another small portion consisting of moderately-differentiated tubular adenocarcinoma components. Therefore, this case raised the possibility that small cell gastric carcinoma may originate from totipotential stem cells of the stomach. Although small cell carcinoma progresses aggressively, and patients with it have an extremely poor prognosis, this patient recovered uneventfully after the surgical resection, and has remained in good health, without any recurrences.</p

    Multi-phasic gene profiling using candidate gene approach predict the capacity of specific antibody production and maintenance following COVID-19 vaccination in Japanese population

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    BackgroundVaccination against severe acute respiratory syndrome coronavirus type 2 is highly effective in preventing infection and reducing the severity of coronavirus disease (COVID-19). However, acquired humoral immunity wanes within six months. Focusing on the different tempo of acquisition and attenuation of specific antibody titers in individuals, we investigated the impact of genetic polymorphisms on antibody production after COVID-19 vaccination.MethodsIn total 236 healthcare workers from a Japanese municipal hospital, who received two doses of the vaccine were recruited. We employed a candidate gene approach to identify the target genetic polymorphisms affecting antibody production after vaccination. DNA samples from the study populations were genotyped for 33 polymorphisms in 15 distinct candidate genes encoding proteins involved in antigen-presenting cell activation, T cell activation, T-B interaction, and B cell survival. We measured total anti-SARS-Cov2 spike IgG antibody titers and analyzed the association with genetic polymorphisms at several time points after vaccination using an unbiased statistical method, and stepwise logistic regression following multivariate regression.ResultsSignificant associations were observed between seven SNPs in NLRP3, OAS1, IL12B, CTLA4, and IL4, and antibody titers at 3 weeks after the first vaccination as an initial response. Six SNPs in NLRP3, TNF, OAS1, IL12B, and CTLA4 were associated with high responders with serum antibody titer &gt; 4000 BAU/ml as boosting effect at 3 weeks after the second vaccination. Analysis of long-term maintenance showed the significance of the three SNPs in IL12B, IL7R, and MIF for the maintenance of antibody titers and that in BAFF for attenuation of neutralizing antibodies. Finally, we proposed a predictive model composed of gene profiles to identify the individuals with rapid antibody attenuation by receiver operating characteristic (ROC) analysis (area under the curve (AUC)= 0.76, sensitivity = 82.5%, specificity=67.8%).ConclusionsThe candidate gene approach successfully showed shifting responsible gene profiles and initial and boosting effect mainly related to the priming phase into antibody maintenance including B cell survival, which traces the phase of immune reactions. These gene profiles provide valuable information for further investigation of humoral immunity against COVID-19 and for building a strategy for personalized vaccine schedules

    Helicobacter pylori lipopolysaccharide from type I, but not type II strains, stimulates apoptosis of cultured gastric mucosal cells

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    The cag pathogenicity island (cag PAI) genes are a major determinant of virulence of Helicobacter pylori (Hp). Lipopolysaccharide (LPS) purified from the cag PAI-positive (type I) strains induced apoptosis of primary cultures of guinea pig gastric mucosal cells. Lipid A catalyzed this apoptosis. These cells expressed the Toll-like receptor 4 (TLR4) mRNA and its protein, and type I Hp LPS phosphorylated transforming growth factor β-activated kinase 1 (TAK1) and TAK1-binding protein 1 (TAB1) in association with up-regulation of the TLR4 expressions, suggesting that type I Hp LPS evoked distinct TLR4 signaling. In contrast, Hp LPS from type II strains with complete or partial deletion of the cag PAI genes did not phosphorylate TAK1 and TAB1 and failed to induce apoptosis. Accelerated apoptosis of gastric epithelial cells is one of the important events relevant to chronic, atrophic gastritis caused by Hp infection. The difference in proapoptotic action of LPS between the type I and II strains may support an important role of the cag PAI genes in the pathogenesis of gastric lesions caused by Hp infection

    Irinotecan Plus Mitomycin C as Second-Line Chemotherapy for Advanced Gastric Cancer Resistant to Fluoropyrimidine and Cisplatin: A Retrospective Study

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    Background. S-1 plus cisplatin has been established to be standard first-line chemotherapy for advanced gastric cancer in Japan. The optimal second-line treatment refractory to S-1 plus cisplatin remains unclear. Methods. We retrospectively studied the efficacy, toxicity, and survival of irinotecan plus mitomycin C in patients with advanced gastric cancer refractory to a fluoropyrimidine plus cisplatin. Results. Twenty-four patients were studied. Prior chemotherapy was S-1 plus cisplatin in 15 patients, S-1 plus cisplatin and docetaxel in 8, and 5-fluorouracil plus cisplatin with radiotherapy in 1. The overall response rate was 17.4%. The median overall survival was 8.6 months, and the median progression-free survival was 3.6 months. Grade 3 or 4 toxicities included leukopenia (33%), neutropenia (50%), anemia (33%), thrombocytopenia (4%), anorexia (13%), diarrhea (4%), and febrile neutropenia (13%). Conclusion. A combination of irinotecan and mitomycin C is potentially effective in patients with advanced gastric cancer refractory to a fluoropyrimidine plus cisplatin
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