著者

Daisuke Nose Yuhei Shiga Ryou-u Takahashi Yuki Yamamoto Yasunori Suematsu Takashi Kuwano Makoto Sugihara Miyuki Kanda Hidetoshi Tahara Shin-ichiro Miura

出版者

The Japanese Circulation Society

雑誌

Circulation Reports (ISSN:24340790)

巻号頁・発行日

pp.CR-23-0038, (Released:2023-07-11)

参考文献数

52

被引用文献数

2

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Background: The utility of telomere G-tail length to predict coronary artery disease (CAD) remains controversial. CAD results from coronary artery narrowing due to cholesterol and lipid accumulation, augmented by inflammatory cells and other factors. This study explored the significance of telomere G-tail length in suspected CAD patients.Methods and Results: In all, 95 patients with suspected CAD or ≥1 cardiac risk factor underwent coronary computed tomography angiography (CCTA). We measured leukocyte telomere length and G-tail length using a hybrid protection method, and diagnosed the presence of CAD using CCTA. Associations between G-tail length and the presence of CAD, the number of stenosed coronary arteries, and brachial-ankle pulse wave velocity (baPWV) were analyzed. No significant difference was observed in G-tail length when comparing groups with or without CAD or statin treatment. However, in the non-statin group, G-tail length was significantly shorter in patients with 3-vessel disease compared with 1-vessel disease. Dividing the group using a baPWV of 1,300 cm/s, telomere G-tail length was significantly shorter in the high-risk (baPWV ≥1,300 cm/s) group.Conclusions: The clinical utility of telomere G-tail length as a CAD risk indicator seems limited. There was a trend for longer telomere G‐tail length in the statin‐treated group. Moreover, telomere G-tail length was reduced in patients at high-risk of cardiovascular events, aligning with the trend of a shortening in telomere G-tail length with CAD severity.

著者

Mohammad Ibrahim QASIMI Susumu FUKUZAWA Ken SUENAGA Jun KAMBE Chunmei LI Shozo TOMONAGA Takahiro KAWASE Takamitsu TSUKAHARA Kazuhiko HIRAYAMA Ryo INOUE Yuki YAMAMOTO Kentaro NAGAOKA

出版者

JAPANESE SOCIETY OF VETERINARY SCIENCE

雑誌

Journal of Veterinary Medical Science (ISSN:09167250)

巻号頁・発行日

pp.23-0080, (Released:2023-05-03)

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L-amino acid oxidase (LAAO) is a metabolic enzyme that converts L-amino acids into ketoacids, ammonia, and hydrogen peroxide (H2O2). The generated H2O2 has previously been shown to have antibacterial and gut microbiota-modulatory properties in LAO1 knock-out (KO) mice. Since most microbial metabolites reach the liver through the portal vein, we examined gut-liver interactions in LAO1 KO mice. We found lower total cholesterol levels, higher glutamic pyruvic transaminase (GPT) levels in the serum, and higher pro-inflammatory cytokine mRNA expression in the liver tissue. In wild-type (WT) mice, LAO1 was expressed in gut tissues (ileum and colon). Microbiome analysis revealed that the abundance of some bacteria was altered in LAO1 KO mice. However, short-chain fatty acid (SCFAs) levels in cecal feces and gut permeability did not change. Fecal microbiota transplantation (FMT) revealed that feces from LAO1 KO mice slightly stimulated pro-inflammatory cytokine expression in the liver. During metabolomic analysis, 5-Aminolevulinic acid (5-ALA) was the only metabolite found to be significantly upregulated in the portal and abdominal veins of the LAO1 KO mice. Intraperitoneal administration of 5-ALA to WT mice significantly increased IL-6 mRNA expression in the liver. These observations suggest that gut LAO1 plays a role in regulating 5-ALA production and that a high level of 5-ALA stimulates the liver to increase pro-inflammatory cytokine expression by disrupting LAO1 in mice.

著者

Kuniharu Imai Kento Takeda Keisuke Fujii Chiyo Kawaura Takuya Nishimoto Masaki Mori Yuki Yamamoto Takashi Izumi

出版者

The Japanese Society for Neuroendovascular Therapy

雑誌

Journal of Neuroendovascular Therapy (ISSN:18824072)

巻号頁・発行日

pp.oa.2022-0041, (Released:2022-10-28)

参考文献数

13

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Objective: Neuroendovascular treatments are less invasive than surgical clipping. However, the number of fluoroscopy runs may be greater when a contrast medium is used than when routine angiography is performed. Several recent studies have suggested that an iodinated contrast medium causes an increase in the radiation dose. Therefore, it is clinically important to identify physical factors causing amplification of the radiation dose. The purpose of this study was to investigate how dilution of a contrast medium with water influences the amplification effect of the radiation dose using simulation analysis.Methods: Three different types of commercially available contrast media, namely, iopamidol, iohexol, and iodixanol, were diluted 1.7–3.3 times with water and placed in the left brain parenchyma of a numerical brain phantom. Using the Monte Carlo simulation method, the phantom was exposed to X-ray beams under constant exposure conditions, and the energy absorbed in the entire region of the left brain parenchyma was estimated. At the same time, the content and volume of a contrast medium in the cerebral vessels were predicted on the basis of pharmacokinetic and fractal analyses.Results: The increase in absorbed energy was attributed to secondary electrons emitted from the contrast medium and varied depending on its content and volume. Interestingly, the amount of energy absorbed increased with increasing dilution of the contrast medium. Furthermore, the amplification effect of the radiation dose varied according to the type of contrast medium used.Conclusion: These results suggest that the amplification effect of the radiation dose is closely related to an increase in the cross-sectional area in which the X-rays interact with the contrast medium, which is caused by increased distribution of contrast medium in the cerebral vessels. When the contrast medium is diluted with water, its spread in the cerebral vessels plays a more important role than its content in the amplification effect of the radiation dose.

著者

Takashi Fukuda Sekiya Koike Syumpei Miyakawa Hiroto Fujiya Yuki Yamamoto

出版者

一般社団法人日本体力医学会

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.6, no.4, pp.241-249, 2017-09-25 (Released:2017-07-12)

参考文献数

41

被引用文献数

3

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The aim of this study is to understand the head impact during actual collisions between American football players from Japanese universities. The subjects of this study were 23 players who belonged to T university in the Kantoh Collegiate American Football Association Division 2. We used a Vector Mouthguard (i1 Biometrics Inc.) equipped with 6 degrees of freedom (DOF) to measure the head linear acceleration (LA) and rotational acceleration (RA) as well as the head injury criterion (HIC), impact location, and number of impacts during collisions. The average number of collisions per player during a practice and during a game was 14.3 and 15.7, respectively. In terms of positions, the ratio (1:1.3) of total number of impacts for backs to linemen in Japan is lower than that (1:3) in the USA. Both during the games and practices, the range of 10 g < X ≤ 15 g in the average peak LA values was the most frequent, and the distributions were largely skewed toward low values (p < 0.05). The medians during the games and practices were 16.77 g and 15.87 g, respectively. The number of collisions during practices in Japan was significantly higher than that in the USA. Particularly, linemen undergo more head collisions than those of backs. Another common factor is that the impact of head collision during a game is significantly higher than that during a practice. However, data on Japanese university players is limited, and further data collection should be done before determining an accurate estimate of the practical concussion risk threshold.

著者

Seiko Toyozawa Chikako Kaminaka Fukumi Furukawa Yasushi Nakamura Hiroshi Matsunaka Yuki Yamamoto

出版者

日本組織細胞化学会

雑誌

ACTA HISTOCHEMICA ET CYTOCHEMICA (ISSN:00445991)

巻号頁・発行日

vol.45, no.5, pp.293-299, 2012 (Released:2012-10-31)

参考文献数

22

被引用文献数

11 19

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The CXCR4/CXCL12 pathway has recently been reported to be involved in stimulating the metastasis of many different neoplasms, in which CXCR4 activates various phenomena such as chemotaxis, invasion, angiogenesis and proliferation. The purpose of this study was to analyze a possible association between the expression of chemokine receptors CXCR4, CCR6 and CCR7 with the clinicopathological features of cutaneous malignant melanoma, and to assess the usefulness of these chemokine receptors for diagnosis and prognosis. In our study, a percentage of immunoexpression of both CXCR4 and its ligands CXCL12 was associated with high clinical risk. In contrast, the patients with a low immunoexpression of CXCR4 and CXCL12 had low clinical risk. CCR6 and CCR7 immunoexpressions were also correlated with some clinical parameters, but seemed no more useful than CXCR4. These data suggest that the assessment of CXCR4 immunoexpression is a novel tool for predicting tumor aggressiveness in malignant melanomas, and in particular, a high immunoexpression percentage of CXCR4 and CXCL12 might be a sign of a poor prognosis.

著者

Shuji Fujii Yuki Yamamoto

出版者

特定非営利活動法人日本バイオレオロジー学会

雑誌

Journal of Biorheology (ISSN:18670466)

巻号頁・発行日

vol.30, no.1, pp.27-33, 2016 (Released:2016-10-25)

参考文献数

36

被引用文献数

2

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Kinetics of the orientation transition in the triblock copolymer lamellar phase is studied by viscometry. We find that the strain-controlled mechanism dominates the transition kinetics. We propose a possible scenario of the orientation transition from the viewpoint of the dislocation dynamics. We could also evaluate the critical shear rate of the orientation transition by assuming the limiting velocity of the dislocations under shear. Evaluated value is in good agreement with the experimental observation. The nucleation of the dislocations might be necessary for the orientation transition.

著者

Yuki YAMAMOTO Tatsuya YAMAMOTO Natsuki YUTO Thomas B. HILDEBRANDT Imke LUEDERS Gudrun WIBBELT Osamu SHIINA Yasushi MOURI Keisuke SUGIMURA Sayuri SAKAMOTO Saroch KAEWMANEE Kentaro NAGAOKA Gen WATANABE Kazuyoshi TAYA

出版者

日本繁殖生物学会

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.1111070413-1111070413, (Released:2011-11-11)

被引用文献数

2 13

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The objective of the present study was to define the secretion of prolactin (PRL) in pregnant African and Asian elephants. Levels of immunoreactive (ir-) PRL in serum and placental homogenates were measured by a heterologous radioimmunoassay (RIA) based on an ovine and human RIA system, and the localization of immunoreactive (ir-) PRL in the placenta was detected by immunohistochemistry using anti-human PRL. Circulating ir-prolactin clearly showed a biphasic pattern during pregnancy in African and Asian elephants. Serum levels of ir-PRL started to increase from the 4-6th month of gestation and reached the first peak level around the 11-14th month. A second peak of circulating ir-PRL levels was observed around the 18-20th month of gestation followed by an abrupt decline after parturition. In contrast, in a case of abortion of an African elephant, the second peak of ir-PRL was not observed, and the levels remained low for about four months until parturition. The weight of the fetus delivered at the 17th month of gestation was 23.5 kg, which was quite small compared with normal fetuses in previous reports. Ir-PRL was detected in placental homogenates, and immunolocalization was observed in trophoblasts in both the African and Asian elephants, indicating that the placenta is the source of ir-PRL during pregnancy in elephants. The present results clearly demonstrated that circulating ir-PRL shows a biphasic pattern during normal pregnancy and that the placenta appears to be an important source of circulating ir-PRL during pregnancy in both African and Asian elephants.