The Tohoku Journal of Experimental Medicine
Online ISSN : 1349-3329
Print ISSN : 0040-8727
ISSN-L : 0040-8727
Volume 246 , Issue 3
November
Showing 1-7 articles out of 7 articles from the selected issue
Regular Contribution
  • Youlim Kim, Yeon Joo Lee, Young-Jae Cho, Ho Il Yoon, Jae Ho Lee, Choon ...
    Type: Regular Contribution
    2018 Volume 246 Issue 3 Pages 147-153
    Published: 2018
    Released: November 06, 2018
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    Chronic fibrosing interstitial lung disease (ILD)s are characterized by chronic progressive fibrosis of lung which include idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia (NSIP), and connective tissue disease-associated interstitial lung disease (CTD-ILD). IPF is an irreversible fibrotic lung disease which results in respiratory failure. Although NSIP and CTD-ILD can be improved or stable by treatment with corticosteroid or immunosuppressant, some of them progress to fibrotic lung diseases. Aspiration of gastric contents is suggested as an aggravating factor of ILDs. We measured pepsin, a marker of gastric aspiration, in bronchoalveolar lavage (BAL) fluid of chronic fibrosing ILD patients to evaluate the association between BAL fluid pepsin and prognosis of chronic fibrosing ILDs. Patients with chronic fibrosing ILDs, who underwent bronchoscopy between December 2010 and April 2015 were prospectively enrolled. Pepsin levels were measured using a commercial ELISA kit. Clinical characteristics, lung function data, and mortality were analyzed. Fifty-one patients with chronic fibrosing ILDs were enrolled (26 with IPF, 15 with NSIP, and 10 with CTD-ILD). Pepsin levels in BAL fluid were 69.87 ± 74.16 ng/mL in IPF, 110.68 ± 94.93 ng/mL in NSIP, and 101.87 ± 88.44 ng/mL in CTD-ILDs. There were no statistically significant differences in BAL fluid pepsin levels among patients with the different chronic fibrosing ILDs. In multivariate regression analysis, higher BAL pepsin levels were associated with higher mortality (adjusted odds ratio [aOR] = 1.021, p = 0.025). BAL fluid pepsin may be used as a prognostic marker for predicting mortality in chronic fibrosing ILD patients.

  • Ryusuke Ouchi, Tasuku Kawano, Hitomi Yoshida, Masato Ishii, Tomomitsu ...
    Type: Regular Contribution
    2018 Volume 246 Issue 3 Pages 155-165
    Published: 2018
    Released: November 06, 2018
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    Epidemiologic studies indicate that exposure to psychosocial stress in early childhood is a risk factor of adult-onset asthma, but the mechanisms of this relationship are poorly understood. Therefore, we examined whether early-life stress increases susceptibility to adult-onset asthma by inhibiting the development of respiratory tolerance. Neonatal BALB/c female mice were aerosolized with ovalbumin (OVA) to induce immune tolerance prior to immune sensitization with an intraperitoneal injection of OVA and the adjuvant aluminum hydroxide. Maternal separation (MS) was applied as an early-life stressor during the induction phase of immune tolerance. The mice were challenged with OVA aerosol in adulthood, and allergic airway responses were evaluated, including airway hyper-responsiveness to inhaled methacholine, inflammatory cell infiltration, bronchoalveolar lavage fluid levels of interleukin (IL)-4, IL-5, and IL-13, and serum OVA-specific IgE. We then evaluated the effects of MS on the development of regulatory T (Treg) cells in bronchial lymph nodes (BLN) and on splenocyte proliferation and cytokine expression. In mice that underwent MS and OVA tolerization, the allergic airway responses and OVA-induced proliferation and IL-4 expression of splenocytes were significantly enhanced. Furthermore, exposure to MS was associated with a lower number of Treg cells in the BLN. These findings suggest that exposure to early-life stress prevents the acquisition of respiratory tolerance to inhaled antigen due to insufficient Treg cell development, resulting in Th2-biased sensitization and asthma onset. We provide the evidence for inhibitory effects of early-life stress on immune tolerance. The present findings may help to clarify the pathogenesis of adult-onset asthma.

  • Sumiko Maeda, Yoshimasa Nakazato, Keitaro Hayashi, Morimichi Nishihira ...
    Type: Regular Contribution
    2018 Volume 246 Issue 3 Pages 167-174
    Published: 2018
    Released: November 17, 2018
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    L-type amino acid transporter 1 (LAT1) functions to transport large neutral amino acids, such as leucine, isoleucine, valine, phenylalanine, tyrosine, tryptophan, methionine, and histidine. These amino acids are essential for cell growth and proliferation. Many studies have demonstrated LAT1 expression in various types of cancer, and its high expression level was associated with poor prognosis. However, the significance of LAT1 expression in thymic epithelial tumors is controversial. We conducted this retrospective study to investigate the LAT1 immunoreactivity in thymic epithelial tumors and its impact on prognosis. We analyzed 32 patients with thymoma and 14 patients with thymic carcinoma who underwent surgery at our institute. Immunohistochemical analysis was performed using formalin-fixed paraffin-embedded surgical tissues and an anti-LAT1 polyclonal antibody. We thus found that LAT1 immunoreactivity was undetectable in all of the thymoma specimens, regardless of the subtypes of thymoma. By contrast, LAT1 immunoreactivity was consistently detected in the cytosol of thymic carcinoma cells; namely, all 14 thymic carcinoma specimens demonstrated LAT1 immunoreactivity in the cytosol. Among these 14 thymic carcinoma specimens, four carcinoma specimens also showed LAT1 immunoreactivity in the cell membrane. Survival analysis indicated that the thymic carcinoma with the LAT1 membrane signal was associated with poor prognosis, compared with the specimens with the LAT1 cytosol signal. We therefore propose that LAT1 is expressed in the cytosol of thymic carcinoma cells, which could be a diagnostic marker of thymic carcinoma. Moreover, LAT1 expression in the cell membrane is a prognostic marker of thymic carcinoma.

  • Miho Satoh, Ikue Watanabe, Kyoko Asakura
    Type: Regular Contribution
    2018 Volume 246 Issue 3 Pages 175-182
    Published: 2018
    Released: November 23, 2018
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    In order to retain nursing staff, it is crucial to have a comprehensive understanding of the factors that motivate nurses to stay at an institution. Toward this aim, we identified a variety of factors that strengthen nurses’ intention to stay at their current hospital. A cross-sectional questionnaire survey was conducted at 12 hospitals in the Tohoku and Kanto regions of Japan. Of the 1,034 nurses working in those hospitals, 713 returned the questionnaire (response rate: 69.0%). Of these, we analysed the data of 485 nurses (17.42 ± 9.83 years of clinical experience, 95.3% female) (valid response rate: 46.9%) who met the inclusion criteria of planning to stay at their current hospital and completing all questionnaire items. An exploratory factor analysis indicated that variables strengthening intention to stay at the current hospital could be grouped into five factors: “comfortable workplace environment,” “passive motivational factors,” “convenience of hospital location,” “favorable work-life balance,” and “fulfilment in nursing.” Nurses who were married or had children placed a higher priority on a “favorable work-life balance” in remaining at their current workplace. Regular employees or nurses working in the smaller cities tended to display higher “passive motivational factors,” which comprised various extrinsic factors. Though extrinsic factors are considered to make only short-term contributions to employee retention, they could generate positive synergistic effects when combined with intrinsic motivations such as “fulfilment in nursing.” Effective nurse-retention strategies should be developed by capitalizing on the interaction among the five factors that strengthen nurses to stay at their current hospital.

  • Kyoko Kawaida, Hisashi Yoshimoto, Ryohei Goto, Go Saito, Yasukazu Ogai ...
    Type: Regular Contribution
    2018 Volume 246 Issue 3 Pages 183-189
    Published: 2018
    Released: November 27, 2018
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    Binge drinking by college students is a problematic behavior. However, data on binge drinking and the reasons for drinking by college students in Japan are scarce. We explored the reasons for drinking among college students. The study used a cross-sectional design and a self-administered questionnaire. From December 2016 to March 2017, we sampled undergraduate and graduate students aged 20 or older at 35 colleges in the Kanto region of Japan. The questionnaire addressed 1) frequency of drinking alcohol, 2) amount of drinking per day, 3) frequency of binge drinking in the past year, and 4) reasons for drinking (with 12 possible responses). The t-test was used to compare the means between binge drinkers and non-binge drinkers. Logistic regression analysis was conducted on binge drinking and the reasons for drinking. The participants included 303 men and 260 women. Significant differences between men and women included the presence of binge drinking (men: 74.9%; women: 59.6%). Among male students, the statistically significant reasons given for binge drinking were “to feel happy or be in a good mood” and “to relieve stress,” whereas among female students, the reasons were “to feel happy or be in a good mood,” “to facilitate interpersonal relationships,” “to forget something bad,” and “to relieve stress.” The reasons for drinking associated with binge drinking were identified. It is important to incorporate these results into preventive education about binge drinking aimed at college students in Japan.

  • Hogil Kim, Tae-Won Jang, Hyoung-Ryoul Kim, Seyoung Lee
    Type: Regular Contribution
    2018 Volume 246 Issue 3 Pages 191-197
    Published: 2018
    Released: November 28, 2018
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    Many Korean bus drivers work long hours, which causes fatigue and increased risk of accidents during driving. Their fatigue due to long working hours may cause a significant accident accompanied by injuries of the general population. The present study aimed to evaluate the fatigue and accident risk in Korean commercial bus drivers. The subjects were 16 city and express bus drivers with various work schedules: 2 shifts (2 shifts in a day), WR (duty-off), W2R (duty-duty-off), and W4R2 (duty-duty-duty-duty-off-off). We measured the subjects’ heart rate in their workplace during their work and calculated relative heart rate (RHR) and maximum acceptable work time (MAWT), the maximum amount of time for which workers can sustain their workload without physical fatigue. Fatigue and risk index, which is a tool for assessing the risk from fatigue in the safety critical workers, was calculated using the subjects’ work schedule. RHR ranged from 9.7 to 21.8% and MAWT was shorter than each subject’s actual work hours. Fatigue (45.2-54.4) and risk indices (1.8) were high in WR schedule, which were higher than recommended value (30-35 for fatigue index and < 1.6 for risk index). According to these findings, Korean bus drivers worked long hours beyond their physical abilities, and the fatigue and risk indices were high, especially in WR schedule. It is necessary to prepare the policies to reduce the fatigue and accident risk in the Korean bus drivers including regulation for bus drivers’ driving time restriction.

  • Masahiro Ishii, Takayuki Hoshina, Shun Ichikawa, Daisuke Shimizu, Shun ...
    Type: Regular Contribution
    2018 Volume 246 Issue 3 Pages 199-203
    Published: 2018
    Released: November 28, 2018
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    Neonatal sepsis continues to be a global problem with significant morbidity and mortality, because of the difficulty in predicting its onset with clinical symptoms alone. Thus, the presence of biomarkers is useful for the diagnosis of neonatal sepsis. Presepsin is a 13-kDa truncated form of soluble CD14 that is produced through proteolytic cleavage on activated monocytes. Presepsin, consisting of 64 amino acid residues, has been proposed as a reliable biomarker for the early diagnosis of sepsis in neonates. However, some biomarkers for the diagnosis of sepsis are elevated during the early neonatal period due to physiological variation, whereas such variation in presepsin levels is uncertain. The objective of this study is to investigate the physiological variation in plasma presepsin levels during the early neonatal period. This prospective study included 30 full-term healthy neonates, including 15 neonates delivered by cesarean section. Plasma presepsin levels were examined at birth and on the first day and the fifth day of life in neonates, and the levels on the 5th day of life were lower than those at any other points (P < 0.001). Moreover, there was no significant difference of plasma presepsin levels between neonates delivered vaginally and by cesarean section. The physiological variation in plasma presepsin levels was observed during the early neonatal period. Attention needs to be paid when measuring plasma presespsin levels for the screening of sepsis during the early neonatal period.

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