Tatsuya Isomura

Potential risk factors for new onset of back pain disability in Japanese workers: findings from the Japan epidemiological research of occupation-related back pain study.

Study Design. Two-year, prospective cohort data from the Japan epidemiological research of occupation-related back pain study were used for this analysis. Objective. To examine the association between a new onset of low back pain (LBP) with disability and potential risk factors among initially symptom-free Japanese workers. Summary of Background Data. Despite strong evidence that psychosocial issues may influence LBP onset among symptom-free persons, these and other LBP risk factors have not been well investigated in the Japanese workplace. Methods. Of 5310 participants responding to a self-administered baseline questionnaire (response rate: 86.5%), 3194 (60.2%) completed both 1- and 2-year follow-up questionnaires. The baseline questionnaire assessed individual characteristics, ergonomic work demands, and work-related psychosocial factors. The outcome of interest was new-onset LBP with disability during the follow-up period. Incidence was calculated for the participants who reported no LBP during the past year at baseline. Logistic regression was used to explore risk factors associated with new-onset LBP with disability. Results. Of 836 participants who were symptom-free during the preceding year, 33 (3.9%) reported LBP with disability during the 2-year follow-up. In univariate analyses, “history of LBP,” “frequent lifting,” “interpersonal stress at workplace,” and “monotonous tasks” were all significant predictors of LBP incidence. All of these factors remained statistically significant or almost significant in the multivariate analysis adjusting for the other variables as well as age and sex: adjusted odds ratio (OR) and 95% confidence interval (95% CI) for history of LBP (OR: 3.25, 95% CI: 1.53–6.91), frequent lifting (OR: 3.77, 95% CI: 1.16–12.3), interpersonal stress at workplace (OR: 2.42, 95% CI: 1.08–5.43), and monotonous tasks (OR: 2.21, 95% CI: 0.99–4.94). Conclusion. Both ergonomic and work-related psychosocial factors may predict the development of LBP with disability among previously asymptomatic Japanese workers. Thus, workplace interventions aimed at reducing the incidence of LBP should focus on both ergonomic and psychosocial stress.

Development of the Japanese version of the Fibromyalgia Impact Questionnaire (JFIQ): psychometric assessments of reliability and validity

Aim:  To perform a psychometric assessment of the Japanese version of the Fibromyalgia Impact Questionnaire (JFIQ).

Potential risk factors of persistent low back pain developing from mild low back pain in urban Japanese workers.

Study Design Two-year, prospective cohort data from the Japan epidemiological research of occupation-related back pain study in urban settings were used for this analysis. Objective To examine the association between aggravated low back pain and psychosocial factors among Japanese workers with mild low back pain. Summary of Background Data Although psychosocial factors are strongly indicated as yellow flags of low back pain (LBP) leading to disability, the association between aggravated LBP and psychosocial factors has not been well assessed in Japanese workers. Methods At baseline, 5,310 participants responded to a self-administered questionnaire including questions about individual characteristics, ergonomic work demands, and work-related psychosocial factors (response rate: 86.5%), with 3,811 respondents completing the 1-year follow-up questionnaire. The target outcome was aggravation of mild LBP into persistent LBP during the follow-up period. Incidence was calculated for the participants with mild LBP during the past year at baseline. Logistic regression was used to explore risk factors associated with persistent LBP. Results Of 1,675 participants who had mild LBP during the preceding year, 43 (2.6%) developed persistent LBP during the follow-up year. Multivariate analyses adjusted for individual factors and an ergonomic factor found statistically significant or almost significant associations of the following psychosocial factors with persistent LBP: interpersonal stress at work [adjusted odds ratio (OR): 1.96 and 95% confidence interval (95%CI): 1.00–3.82], job satisfaction (OR: 2.34, 95%CI: 1.21–4.54), depression (OR: 1.92, 95%CI: 1.00–3.69), somatic symptoms (OR: 2.78, 95%CI: 1.44–5.40), support from supervisors (OR: 2.01, 95%CI: 1.05–3.85), previous sick-leave due to LBP (OR: 1.94, 95%CI: 0.98–3.86) and family history of LBP with disability (OR: 1.98, 95%CI: 1.04–3.78). Conclusions Psychosocial factors are important risk factors for persistent LBP in urban Japanese workers. It may be necessary to take psychosocial factors into account, along with physical work demands, to reduce LBP related disability.

Assessment of psychosocial risk factors for the development of non-specific chronic disabling low back pain in Japanese workers—findings from the Japan epidemiological research of Occupation-related Back pain (JOB) study

To investigate the associations between psychosocial factors and the development of chronic disabling low back pain (LBP) in Japanese workers. A 1 yr prospective cohort of the Japan Epidemiological Research of Occupation-related Back Pain (JOB) study was used. The participants were office workers, nurses, sales/marketing personnel, and manufacturing engineers. Self-administered questionnaires were distributed twice: at baseline and 1 yr after baseline. The outcome of interest was the development of chronic disabling LBP during the 1 yr follow-up period. Incidence was calculated for the participants who experienced disabling LBP during the month prior to baseline. Logistic regression was used to assess risk factors for chronic disabling LBP. Of 5,310 participants responding at baseline (response rate: 86.5%), 3,811 completed the questionnaire at follow-up. Among 171 eligible participants who experienced disabling back pain during the month prior to baseline, 29 (17.0%) developed chronic disabling LBP during the follow-up period. Multivariate logistic regression analysis implied reward to work (not feeling rewarded, OR: 3.62, 95%CI: 1.17–11.19), anxiety (anxious, OR: 2.89, 95%CI: 0.97–8.57), and daily-life satisfaction (not satisfied, ORs: 4.14, 95%CI: 1.18–14.58) were significant. Psychosocial factors are key to the development of chronic disabling LBP in Japanese workers. Psychosocial interventions may reduce the impact of LBP in the workplace.

Can standing back extension exercise improve or prevent low back pain in Japanese care workers

Abstract Background: We suggested a standing back extension exercise ‘One Stretch’ based on the McKenzie method, to examine the ability to improve or prevent low back pain (LBP) in Japanese care workers. Methods: We conducted a single-center, non-randomized, controlled study in Japan. Care workers in an intervention group received an exercise manual and a 30-minute seminar on LBP and were encouraged with a group approach, while care workers in a control group were given only the manual. All care workers answered questionnaires at the baseline and end of a 1-year study period. The subjective improvement of LBP and compliance with the exercise were evaluated. Results: In all, 64 workers in the intervention group and 72 in the control group participated in this study. More care workers in the intervention group exercised regularly and improved or prevented LBP than in the control group (P = 0·003 and P<0·0001, respectively). In the intervention group, none had a first medical consultation or were absent from disability for LBP by the end of the study period. Conclusion: The exercise ‘One Stretch’ would be effective to improve or prevent LBP in care workers. Our group approach would lead to better compliance with the exercise.

Identification of Risk Factors for New-Onset Sciatica in Japanese Workers: Findings From the Japan Epidemiological Research of Occupation-Related Back Pain Study

Study Design. Two-year, prospective cohort data collected for the Japan epidemiological research of Occupation-related Back pain study were used for the analysis. Objective. To identify potential risk factors for the development of new-onset sciatica in initially symptom-free Japanese workers with no history of sciatica. Summary of Background Data. Although the associations between individual and occupational factors and cases of new-onset sciatica are established, the effect of psychosocial factors on the development of sciatica has still not been adequately clarified. Methods. In total, 5310 participants responded to a self-administered baseline questionnaire (response rate: 86.5%). Furthermore, 3194 (60.2%) completed both 1- and 2-year follow-up questionnaires. The baseline questionnaire assessed individual characteristics, ergonomic work demands, and work-related psychosocial factors. The outcome of interest was new-onset sciatica with or without low back pain during the 2-year follow-up period. Incidence was calculated for participants who reported no low back pain in the preceding year and no history of lumbar radicular pain (sciatica) at baseline. Logistical regression assessed risk factors associated with new-onset sciatica. Results. Of 765 eligible participants, 141 (18.4%) reported a new episode of sciatica during the 2-year follow-up. In crude analysis, significant associations were found between new-onset sciatica and age and obesity. In adjusted analysis, significant associations were found for obesity and mental workload in a qualitative aspect after controlling for age and sex. Consequently, in multivariate analysis with all the potential risk factors, age and obesity remained statistically significant (odds ratios: 1.59, 95% confidence interval: 1.01–2.52; odds ratios: 1.77, 95% confidence interval: 1.17–2.68, respectively). Conclusion. In previously asymptomatic Japanese workers, the risk of developing new-onset sciatica is mediated by individual factors. Our findings suggest that the management of obesity may prevent new-onset sciatica. Level of Evidence: 3

Central nervous system effects of the second-generation antihistamines marketed in Japan--review of inter-drug differences using the proportional impairment ratio (PIR)-.

Background Second-generation antihistamines (AHs) have, in general, fewer sedative effects than the first-generation. However, important inter-drug differences remain in the degree of cognitive and/or psychomotor impairment. The extent to which a particular compound causes disruption can be conveniently compared, to all other AHs, using the Proportional Impairment Ratio (PIR). Although the PIR can differentiate the relative impairment caused by individual drugs, there is no indication of the reliability of the ratios obtained. Objective To calculate the PIRs –together with 95% confidence intervals (CIs), as an index of reliability– and compare AHs currently, or soon to be, available in Japan, with respect to their intrinsic capacity to cause impairment. Methods Results from studies of cetirizine, desloratadine, ebastine, fexofenadine, levocetirizine, loratadine, mequitazine, and olopatadine were included in the PIR calculations. All data utilised came from crossover studies in healthy volunteers which were randomised and placebo and positive-internal controlled. Existing databases from studies reporting the sedative effects of AHs on objective (speed, accuracy, memory) and subjective (feeling) psychometrics were augmented, via results from suitable studies published after the previous reviews. The null value for a PIR was one. Results A total of 45 studies were finally included for this review. Of the AHs assessed, fexofenadine, ebastine, and levocetirizine showed a PIR for objective tests of 0. However, only fexofenadine (PIR = 0.49) had an upper limit of the 95% CI of less than 1. Fexofenadine, levocetirizine, desloratadine, olopatadine, loratadine, and mequitazine all had a PIR for subjective ratings of 0, but the upper limits of the 95% CIs were all in excess of 1, although fexofenadine (PIR = 2.57) was the lowest. Conclusions The results show that there are differences between second-generation AHs in the extent of sedation produced. However, subjective ratings indicate that patients may not necessarily be aware of this.

Development of the Japanese Version of the Leeds Assessment of the Neuropathic Symptoms and Signs Pain Scale: Diagnostic Utility in a Clinical Setting.

We aimed to assess the diagnostic utility of the linguistically validated Japanese version of the Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale (LANSS‐J) as a screening tool for neuropathic pain in the clinical setting.

Intraepithelial CD8+ lymphocytes as a predictive diagnostic biomarker for the remission of oral lichen planus

Oral lichen planus (OLP) is an autoimmune inflammatory disease of the oral mucosa whose etiology remains unknown. Moreover, the possibility of OLP being a premalignant change is under debate. Various types of immune cells infiltrate the OLP lesion and affect its clinicopathological features. However, the diversity of infiltrating immune cells has not been fully clarified in relation to OLP diagnosis. In this study, we quantitatively examined CD8+ lymphocyte infiltration by immunohistochemistry, which is the principal effector of cytotoxic immune reaction in 123 cases of OLP specimens. Our examination revealed that high-grade intraepithelial CD8+ lymphocyte infiltration was associated with a high remission rate. Evaluation of the infiltration of T-bet+ and FoxP3+ lymphocytes, which corresponded to the Th1 and Treg CD4+ subsets, respectively, showed that intraepithelial CD8+ lymphocytes were associated with the remission rate in the subgroup with a higher T-bet/FoxP3 subset balance that is inducible for cytotoxic immunity. We also investigated the cutoff value of CD8+ lymphocyte infiltration for histopathological diagnosis. By microscopic counting, 16 cells/high-power field, which was also confirmed in the validation cohort, was established as the cutoff value for intraepithelial CD8+ lymphocyte infiltration for predicting the remission of OLP. Remitting OLP might be different from refractory OLP in terms of etiology and clinical behavior. Thus, intraepithelial CD8+ lymphocytes may serve not only as a predictive biomarker for remission but also as an area for further biomedical research regarding the etiology and premalignant potential of OLP.

Diagnostic Significance of Intratumoral CD8+ Tumor Infiltrating Lymphocytes in Medullary Carcinoma ☆ ☆☆

Invasive ductal carcinomas of breast with marked stromal lymphocytic infiltration have come to be classified as lymphocyte-predominant breast cancer (LPBC) because it obtains high pathological complete response rates with neoadjuvant chemotherapy. Medullary carcinoma (MC), which is independent from LPBC, is a rare histological subtype of invasive breast carcinoma accompanied by abundant lymphoplasmacytic infiltration as LPBC. Although MC shows marked cellular and structural atypia, it usually has a favorable outcome. It is occasionally difficult to distinguish MC from LPBC because both subtypes have nonspecific morphological features according to the present diagnostic criteria. Herein, we adopted multiplexed fluorescent immunohistochemistry to perform quantitative and simultaneous analyses of tumor-infiltrating lymphocytes (TILs) considering their spatial distribution and examined focal immune reaction differences between MC and LPBC. We found that CD8+ TILs are predominant in the intratumoral region, whereas CD4+ TILs are less common in MC. In non-luminal-type cancers, the numbers of stromal and intratumoral CD8+ TILs were significantly higher in MC than in LPBC. Stratified analyses by CD4+ TIL subsets showed robust infiltration of intratumoral CD8+ TILs in non-luminal-type MC even in suppressive environments, such a low T helper 1-to-regulatory T cell ratio. Our results suggest that extensive intratumoral CD8+ TIL infiltration might well be a promising biomarker for distinguishing MC from LPBC, especially in non-luminal-type cancers. Intratumoral CD8+ TILs and nonluminal intrinsic subtypes may serve as diagnostic characteristics allowing reliable histological criteria to be established for reproducibly diagnosing MC.