Published papers

Background: SARS-CoV-2 vaccination has started worldwide, including Japan. Although high rates of vaccine response and adverse reactions of BNT162b2 vaccine have been reported, knowledge about the relationship between sex differences and antibody response is limited. Furthermore, it is uncertain whether adverse reactions are associated with the vaccine response. Methods: This prospective observational study included 673 Japanese participants working in a medical school and its affiliated hospital in Tokyo, Japan (UMIN000043340). Serum samples were collected before the first dose and three weeks after the second dose of BNT162b2 vaccine, and antibody titers against the receptor-binding domain of the spike protein of SARS-CoV-2 were measured. Answers to questionnaires about background characteristics and adverse reactions were obtained at the time of sample collection, and the relationship between antibody titers was analyzed. Results: After excluding participants who did not complete receiving two doses of vaccination or two series of serum sample collection, 646 participants were analyzed. Although all participants became sero-positive after vaccination, antibody titers were highly variable among individuals (260.9–57,399.7A U/mL), with a median titer of 13478.0AU/mL. Mean titer was higher in females than in males and higher in young (≤45 years old) participants than in aged (>45 years old) participants. Participants who experienced adverse reactions demonstrated a higher antibody titer after vaccination than those without adverse reactions. Multivariable analysis demonstrated that young age, female sex, and adverse reactions after the second dose were independently related to higher antibody titers after the second dose. Discussion: A favorable antibody response was observed after two doses of BNT162b2 vaccination among mostly healthy Japanese participants, especially among female and young participants. Although further investigation is essential, our results imply that the systemic adverse reactions (i.e., fever and general fatigue) are associated with a higher antibody response that indicates the acquisition of humoral immunity.

© 2019 International Institute of Anticancer Research. All Rights Reserved. Background/Aim: The present study assessed whether and how tumor cells undergoing hypoxia contribute to disease progression after moving to areas with different oxygen conditions. Materials and Methods: Human colorectal carcinoma HCT116 cells cultured under mild hypoxia were subjected to in vivo experiments using transfer to immunodeficient murine recipients and to in vitro experiments using pharmacological inhibition of fatty acid β-oxidation (FAO). Results: Bone involvement and hepatic metastases were accelerated in transfer models of hypoxically cultured HCT116 cells. Hypoxic HCT116 cells exhibited FAO-dependent glycogen synthesis. FAO-dependent and -independent induction of gene expression also occurred under hypoxia. The distribution of glucose transporter 1 expression compared with heme oxygenase 1 expression in HCT116 cell spheroids seemed consistent with differential dependence of hypoxic expression of these molecules on FAO. Conclusion: These results provide insights into the contribution of hypoxia to tumor progression and the relevance of FAO.

© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ. Aims Clot waveform analysis (CWA) has been reported to extend the interpretation of clotting time measurement. The parameters obtained from successive derivatives of the clotting reaction curves reflect the rates of activation of individual coagulation factors, theoretically dissecting the cascade pathway. This study aims to assess the in vitro effects of direct thrombin inhibitors (DTIs) and activated factor X (FXa) inhibitors. Methods CWA was applied to the activated partial thromboplastin time (APTT) assay of plasma samples spiked with each drug. For CWA of APTT measurement curves (APTT-CWA), the positive mode of clotting reaction curves was defined as the direction towards fibrin generation. Results All the maximum positive values in the successive derivatives were decreased dependently on the concentrations of each drug. Moreover, the negative values in the second and third derivatives appeared putatively due to consumption of thrombin and factor FXa, respectively, to form complexes with plasma serine protease inhibitors. The decrease of the maximum negative values observed dependently on the concentrations of each drug appeared to be consistent with the decreased generation of thrombin and factor FXa. The analysis of Hill coefficients of each drug in the dose-response of changes in the APTT-CWA parameters revealed a difference in anticoagulant cooperativity between DTIs versus FXa inhibitors. Conclusions The APTT-CWA demonstrated evidence for the blockade of thrombin-positive feedback by DTIs and FXa inhibitors and that for the differences in anticoagulant cooperativity between them. The results demonstrate the usability of CWA for assessment of anticoagulation and provide insights into direct anticoagulants.

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. DNA methylation is a typical epigenetic phenomenon. Numerous methods for detecting global DNA methylation levels have been developed, among which LC-MS/MS has emerged as an excellent method from the viewpoint of sensitivity, reproducibility, and cost. However, LC-MS/MS methods have limitations due to a lack of the stability and the standardization required for a laboratory assay. The present study aimed to establish a robust assay that guarantees highly accurate measurements of global DNA methylation levels. There are at least three facets of the developed method. The first is discovery of the solvent conditions to minimize sodium adducts. The second is improvement of separation of nucleosides by LC using the columns that had not been used in previous similar studies. The third is success in reduction of the uncertainty of the measurement results, which was achieved by the calibration using the ratio of mdC but not the absolute amount in the presence of internal standards. These facets represent the advantage over methods reported previously. Our developed method enables quantification of DNA methylation with a short time length (8 min) for one analysis as well as with the high reproducibility of measurements that is represented by the inter-day CV% being less than 5%. In addition, data obtained from measuring global DNA methylation levels in cultured cell lines, with or without pharmacological demethylation, support its use for biomedical research. This assay is expected to allow us to conduct initial screening of epigenetic alterations or aberration in a variety of cells.

© 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases The QuantiFERON TB Gold Plus (QFT-Plus) test is a newly approved interferon-gamma releasing assay test for detecting latent tuberculosis. Although blood samples for QFT test can be refrigerated for 48 h in lithium-heparin tubes according to package inserts, no published data are available on the effects of sample refrigeration on the test results. We conducted a clinical study that aimed to elucidate whether sample refrigeration for 48 h affects QFT-Plus test results. We collected 2 blood samples each from 40 participants for QFT-Plus; one sample was refrigerated before incubation for QFT-Plus assay, while the other sample was incubated soon after collection and treated as control. After comparing QFT-Plus test results of refrigerated samples and control samples, the concordance rate and kappa coefficient between them were 95% and 0.90, respectively. Thus, blood samples for QFT-Plus test can be refrigerated for 48 h in lithium-heparin tubes without influencing the test results.