The Tohoku Journal of Experimental Medicine
Online ISSN : 1349-3329
Print ISSN : 0040-8727
ISSN-L : 0040-8727
Current issue
May
Displaying 1-8 of 8 articles from this issue
Regular Contribution
  • Tetsuya Akaishi, Shigeki Kushimoto, Yukio Katori, Noriko Sugawara, Kao ...
    Article type: Regular Contribution
    2022 Volume 257 Issue 1 Pages 1-6
    Published: 2022
    Released on J-STAGE: May 13, 2022
    Advance online publication: March 31, 2022
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    The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remained a major global health concern in 2021. To suppress the spread of infection, mass vaccinations have been performed across countries worldwide. In Japan, vaccinations of the first and second doses for most of the nation were performed during the nationwide outbreak of the B.1.617.2 (Delta) variant with the L452R spike protein mutation, and the effectiveness of the vaccinations to suppress the spread of COVID-19 among the people in Japan remains uncertain. In this study, adults aged ≥18 years, who were in contact with patients with COVID-19 and underwent nasopharyngeal swab reverse transcription-polymerase chain reaction (RT-PCR) tests during August and September 2021 at a mass screening test center in Japan, were enrolled. In this period, more than 95% of the COVID-19 infections were reportedly caused by the Delta variant. As a result, a total of 784 adults with recent contact history, including 231 (29.5%) RT-PCR test-positive cases, were enrolled. The test positivity rate was lower in individuals who had been vaccinated twice than in unvaccinated individuals (12.5% vs. 39.0%, p < 0.0001), with the risk ratio of 0.32 (95% confidence interval 0.23-0.46). The vaccine effectiveness was the highest between 7-90 days after the second vaccine dose. In conclusion, two doses of mRNA COVID-19 vaccines effectively suppressed transmission in Japan during the nationwide pandemic of the Delta variant, estimated to have prevented 50-80% of the infection.

  • Junko Fujiwara, Shunsuke Tatebe, Kotaro Nochioka, Hideki Ota, Yasuharu ...
    Article type: Regular Contribution
    2022 Volume 257 Issue 1 Pages 7-15
    Published: 2022
    Released on J-STAGE: May 13, 2022
    Advance online publication: March 24, 2022
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    Right ventricular (RV) dysfunction caused by chronic pulmonary regurgitation (PR) is a major determinant of clinical outcome in adults with repaired tetralogy of Fallot (rTOF). However, the accurate assessment of RV function by conventional echocardiography remains challenging. This study tested the feasibility and usefulness of RV free-wall (RVFW) strain obtained by two-dimensional (2D) speckle-tracking echocardiography (STE) in evaluation of RV function in adults with rTOF by comparing cardiac magnetic resonance (CMR) imaging. We enrolled 22 consecutive patients (male/female, 8/14; mean age, 25.0 years) with rTOF who underwent transthoracic echocardiography at Tohoku University Hospital from July 2016 to June 2019. We measured RVFW strain by STE and compared them with 22 hemodynamically normal subjects (NOR) (male/female, 9/13; mean age, 32.0 years). The correlation between RV strain and CMR-derived RV ejection fraction (RVEF) or PR fraction (PRF) were also evaluated. All rTOF patients had more than moderate PR but were near asymptomatic. RVFW longitudinal strain (RVFW-LS) was significantly decreased in the rTOF group compared with that in the NOR group (−19.6 vs. −24.7, P < 0.01). In the rTOF group, RVFW-LS correlated with PRF (r = 0.44, P < 0.05), whereas RVFW circumferential strain at the mid-ventricular level correlated with RVEF (r = 0.57, P < 0.01). Intra-observer variability of RVFW strain was acceptable. These results indicate that RV systolic function and PR severity in rTOF could be assessed by RVFW strain measured by 2D STE. This method is feasible and can be used as a complement to CMR imaging.

  • Shinsuke Tokoro, Shigeki Koshida, Shunichiro Tsuji, Daisuke Katsura, T ...
    Article type: Regular Contribution
    2022 Volume 257 Issue 1 Pages 17-22
    Published: 2022
    Released on J-STAGE: May 14, 2022
    Advance online publication: April 07, 2022
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    Fetal growth restriction (FGR) is defined as fetuses who have failed to achieve a normal weight for gestational age. FGR is associated with adverse perinatal outcomes, including stillbirth. Pregnant women often perceive decreased fetal movements before intrauterine fetal death. Previous reports on the association between fetal movements and FGR have mainly targeted livebirths, with few focusing on stillbirths. Studying stillbirths, not livebirths, may help improve perinatal adverse outcomes. This study evaluated the association between FGR leading to stillbirth and maternal perception of decreased fetal movement. This was a population-based study reviewing all stillbirths in Shiga Prefecture, Japan for 10 years. We analyzed 219 stillbirth cases, those with versus without FGR. We then compared maternal visits to healthcare providers due to perception of decreased fetal movement between these two groups. There were 82 stillbirths with FGR, and the remaining 137 stillbirth were without FGR. Women with FGR, compared with those without, were significantly less often to visit the outpatient department due to decreased fetal movement (30%; 25/82 vs. 46%; 63/137: P = 0.034). Pregnant women have more difficulty perceiving decreased fetal movements in cases with severe FGR than in those without FGR. Healthcare providers, including midwives, may need to closely monitor FGR pregnancy in addition to instructing pregnant women to be aware of decreased fetal movement.

  • Masako Miyashita, Taku Obara, Mami Ishikuro, Masahiro Kikuya, Shinichi ...
    Article type: Regular Contribution
    2022 Volume 257 Issue 1 Pages 23-32
    Published: 2022
    Released on J-STAGE: May 14, 2022
    Advance online publication: April 07, 2022
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    Asthma and atopic dermatitis are common among schoolchildren. The Great East Japan Earthquake of 2011 caused serious damage to buildings and infrastructure as well as the total or partial collapse of many hospitals and medical clinics. The aim of this study was to examine the association between recurrence or exacerbation (recurrence/exacerbation) of asthma or atopic dermatitis at the time of disaster and allergic symptoms several years later in schoolchildren. A cross-sectional survey was conducted via a parent-administered questionnaire between 2013 and 2015 in Miyagi Prefecture, northeast Japan. We analyzed the data of 2,399 schoolchildren with a diagnosis of asthma and 2,107 with a diagnosis of atopic dermatitis. Among those who had experienced recurrence/exacerbation of their symptoms soon after the disaster, the prevalence of later wheezing and eczema was 71.2% (N = 195) and 81.9% (N = 379), respectively. Recurrence/exacerbation of allergic symptoms just after the disaster was positively associated with wheezing (odds ratio, OR 6.54, 95% confidence interval, 95% CI 4.94-8.67) and eczema (OR 8.12, 95% CI 6.25-10.55) several years later. Disasters might have long-term effects on the allergy symptoms of children. It is necessary to prepare for prevention of recurrence/exacerbation, to treat allergic symptoms, and to support children to continue their allergy treatments and daily care when a disaster strikes.

  • Yingying Chen, Wei Song, Yuan Gao, Xiu Dong, Xinping Ji
    Article type: Regular Contribution
    2022 Volume 257 Issue 1 Pages 33-43
    Published: 2022
    Released on J-STAGE: May 25, 2022
    Advance online publication: March 31, 2022
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    Cancer immunotherapy has dramatically improved the prognosis of non-small cell lung cancer (NSCLC). In tumor cells, programmed death ligand-1 (PD-L1), also known as cluster of differentiation 274 (CD274), is a key target for cancer immunotherapy. Cisplatin (CDDP), a first-class NSCLC treatment drug, reportedly induces PD-L1 expression, and regulates cancer immunity. Herein, the regulatory mechanism of PD-L1 was investigated in CDDP-treated NSCLC and acquired CDDP-resistant NSCLC. Two types of NSCLC cell lines, A549 and H69, and their CDDP-resistant cell lines, A549R and H68R, were used to investigate PD-L1 expression and microRNA mir-181a expression. Murine lung cancer LL/2 cells were injected to mice for in vivo study. Although CDDP induced PD-L1 expression in A549 and H69 cells, A549R and H69R cells expressed extremely higher levels of PD-L1. CDDP-induced mir-181a was detected in A549 and H69 cells, but not A549R and H69R cells. Moreover, the CDDP-induced ATM-mir-181a-c-FOS pathway repressed PD-L1 expression in A549 cells, while A549R cells blocked this negative regulatory mechanism to further increase PD-L1 expression. Exogenous mir-181a in LL/2 cells could repress the intratumoral exhausted T cells, and increase the T cells function, and repress the tumor growth. Increased PD-L1 expression in acquired cisplatin-resistant lung cancer cells is dependent on mir-181a in NSCLC.

  • Fumika Suzuki, Hiroe Sato, Masatoshi Akiyama, Miki Akiba, Osamu Adachi ...
    Article type: Regular Contribution
    2022 Volume 257 Issue 1 Pages 45-55
    Published: 2022
    Released on J-STAGE: May 25, 2022
    Advance online publication: March 31, 2022
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    Left ventricular assist devices (LVAD) improve quality of life (QOL) in many patients with end-stage severe heart failure, but not in some patients. In addition, the burden on caregivers is expected to increase after LVAD patients are discharged. Our study aimed to investigate the impact of LVAD on the QOL of patients and caregivers. Thirty-two LVAD patients were assessed for changes in QOL, mental status, and activity level using the Euro QOL (EQ-5D-5L), Short Form 12 (SF-12), Minnesota Living with Heart Failure Questionnaire, Hospital Anxiety and Depression Scale (HADS), and Frenchay Activities Index. Twenty-four caregivers were assessed for changes in QOL, mental status, and burden of care using the EQ-5D-5L, SF-12, HADS, and Burden Index of Caregiver (BIC-11). The LVAD patients and caregivers responded contemporaneously regarding two points: pre-and post-LVAD. Patients’ physical and mental QOL was significantly improved, but not social QOL and activity level. Caregivers’ QOL and burden of care did not change, and anxiety was reduced (p = 0.028). The patients were divided into two groups based on whether EQ-5D-5L was improved: twelve patients in the unimproved group (UG) and twenty patients in the improved group (IG). In the UG, 50% had LVAD-related strokes (p = 0.001, IG: 0%), and their social QOL decreased (p = 0.023). The activity levels improved in the IG. Multi-dimensional analyses on the QOL in LVAD patients yielded mixed results. Anticipated benefits derived from LVAD therapy may be limited by LVAD-related complications such as stroke that negatively impacts on the QOL.

  • Suguru Hiramoto, Daichi Miyashita, Takao Kimura, Takahiko Niwa, Azusa ...
    Article type: Regular Contribution
    2022 Volume 257 Issue 1 Pages 57-64
    Published: 2022
    Released on J-STAGE: May 27, 2022
    Advance online publication: March 31, 2022
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    This study sought to evaluate the effects of two vaccine doses and the extent of SARS-CoV-2 infection among healthcare workers. We measured immunoglobulin G antibody titers against SARS-CoV-2 nucleocapsid and spike protein among healthcare workers at Gunma University Hospital. In March 2021, prior to BNT-162b2 vaccination, two of 771 participants were seropositive for nucleocapsid and spike protein, whereas 768 were seronegative. The remaining one participant was seropositive for nucleocapsid protein but seronegative for spike protein. A total of 769 participants were seropositive for spike protein after two vaccination doses. The two seropositive participants prior to vaccination showed the highest antibody titers after the second vaccination. They were probably infected with SARS-CoV-2 without clinical symptoms before March 2021. Four weeks after the second vaccination, a younger age was associated with higher antibody titers against SARS-CoV-2 spike protein. Thirty-two weeks after the second vaccination, blood samples were collected from 342 of 769 participants. Antibody titers at 32 weeks after the second vaccination significantly decreased compared with those at 4 weeks after the second vaccination among all age groups. The rate of decrease in antibody titers between 4 and 32 weeks after the second vaccination was greater in the female participants. No sex differences were observed in the antibody titers within each age group. BNT-162b2 vaccination thus induced seroconversion in an age-dependent manner. Serological screening could further establish the likelihood of subclinical SARS-CoV-2 infection.

  • Katsunori Iijima, Mario Jin, Masahito Miura, Kenta Watanabe, Noboru Wa ...
    Article type: Regular Contribution
    2022 Volume 257 Issue 1 Pages 65-71
    Published: 2022
    Released on J-STAGE: May 27, 2022
    Advance online publication: April 07, 2022
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    Disruption of cancer screening programs and diagnoses of gastrointestinal cancers by the COVID-19 pandemic has been reported; however, little attention has been paid to the situation in depopulated areas with low infection rates. Akita Prefecture is one of the most depopulated areas of Japan and has the lowest COVID-19 infection rate per capita; at the same time, the prefecture has been top-ranked for mortality due to gastrointestinal cancer for years. In this population-based study in Akita Prefecture, we investigated the occurrence of gastrointestinal cancers and the number of cancer screening procedures over the five-year period of 2016-2020, employing a database from the collaborative Akita Prefecture hospital-based registration system of cancers. The occurrence of gastrointestinal cancers, especially esophago-gastric cancers, declined by 11.0% in 2020, when the COVID-19 pandemic affected the overall healthcare system, compared with the average of 2016-2019. Nonetheless, the occurrence of advanced-stage (stage IV) esophago-gastric cancers increased by 7.2% in 2020. The decrease in the gastrointestinal cancer diagnosis rate in 2020 coincided with a 30% decline in the total number of regular population-based screening programs. Under the ongoing COVID-19 pandemic, cancer screening was uniformly suspended throughout Japan. Accordingly, the COVID-19 pandemic has substantially disrupted the cancer screening system, leading to delays in diagnoses of gastrointestinal cancer, even in depopulated areas (Akita Prefecture) of Japan with a low prevalence of infection. Suspension of cancer screening procedures during an infectious disease pandemic should be thoroughly considered for each region based on the cancer incidence and infection status in that area.

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