Prevalence of and factors influencing Hikikomori in Osaka City, Japan: A population-based cross-sectional study.

OBJECTIVES: Hikikomori is commonly defined as a social condition in which individuals avoid social participation and relationships beyond their family members by confining themselves to a room or their house for 6 months or longer. Hikikomori has been predominantly considered a problem among young people; however, as the population is ageing, hikikomori has also emerged as a social issue among adults. Nevertheless, no comparative studies have examined the differences in the factors associated with hikikomori among teenagers/young adults and middle-aged/older adults. Thus, this phenomenon has not been thoroughly examined, and it remains unclear whether the risk factors vary between teenagers/young adults and middle-aged/older adults. Based on the Japan Cabinet Office's definition of hikikomori, this cross-sectional study evaluated the prevalence and related factors of hikikomori among the working age population (15-64 years), utilising univariate and multivariate analyses. The study also compared differences in the prevalence of and factors related to hikikomori between teenagers/young adults and middle-aged/older adults. METHODS: We distributed self-administered questionnaires to individual participants and their families between 24 December 2020 and 18 January 2021. RESULTS: Data from an anonymised sample of 3,092 individuals (split into two groups of 15-39 and 40-64 years) were subjected to analysis. The results revealed a hikikomori prevalence of 2.3% in the target population; the prevalence rate was 2.12% among individuals aged 15 to 39 years and 2.42% among those aged 40 to 64 years. The analysis demonstrated strong correlations between hikikomori and several factors, including unemployment, truancy, a history of psychiatric consultation or hospitalisation, being male and the absence of ibasho, which is defined as a place where individuals can feel peace, security, acceptance and belonging. The factors associated with hikikomori differed between teenagers/young adults and middle-aged/older adults. CONCLUSION: Our findings, thus, contribute to existing research by providing a comparative analysis of risk factors across different age groups.

Basic life support for non-traumatic out-of-hospital cardiac arrests during school-supervised sports activities in children: A nationwide observational study in Japan.

Objective: To investigate the prognostic impact of bystander-initiated cardiopulmonary resuscitation (CPR) and public-access automated external defibrillator (AED) use on non-traumatic out-of-hospital cardiac arrest (OHCA) occurring during school-supervised sports activities in children. Methods: From a nationwide database of pediatric OHCAs occurring under school supervision in Japan, data between April 2008 and December 2020 were obtained. We analyzed non-traumatic OHCAs that occurred during school-supervised sports activities among schoolchildren from elementary, junior high, high, and technical colleges. A multivariable logistic regression model was used to evaluate the effect of basic life support (BLS) on 1-month survival with favorable neurological outcomes after OHCA. Results: In total, 318 OHCA cases were analyzed. The 1-month survival with favorable neurological outcomes was 64.8% (164/253) in cases receiving both bystander-CPR and AED application, 40.7% (11/27) in cases receiving CPR only, 38.5% (5/13) in patients receiving AED application only, and 28.0% (7/25) in cases receiving no bystander intervention. Compared with cases receiving no BLS, cases receiving both CPR and AED had a significantly higher proportion of 1-month survival with favorable neurological outcomes (adjusted odds ratio [AOR]: 3.97, 95% confidence interval [CI]: 1.32-11.90, p = 0.014). However, compared to cases receiving no BLS, there was no significant difference in the outcome in the cases receiving CPR only (AOR: 1.35, 95% CI: 0.34-5.29, p = 0.671) and the cases receiving AED application only (AOR: 1.26, 95% CI: 0.25-6.38, p = 0.778). Conclusion: The combination of CPR and AED as BLS performed by bystanders for non-traumatic OHCA during school-supervised sports activities improved the outcomes.

Association of mesothelioma deaths with neighborhood asbestos exposure due to a large-scale asbestos-cement plant.

A causal relationship between mesothelioma and occupational asbestos exposure is well known, while some studies have shown a relationship to non-occupational exposures. The aim of this study was to quantify the risk of mesothelioma death associated with neighborhood asbestos exposure due to a large-scale asbestos-cement (AC) plant in Amagasaki, Japan, adjusting properly risk factors including occupational exposures. We conducted a nested case-control study in which a fixed population of 143,929 residents who had been living in Amagasaki City between 1975 and 2002 were followed from 2002 to 2015. All 133 cases and 403 matched controls were interviewed about their occupational, domestic, household, and neighborhood asbestos exposures. Odds ratios (ORs) for mesothelioma death associated with the neighborhood exposure were estimated by a conditional logistic-regression model. For quantitative assessments for neighborhood exposure, we adopted cumulative indices for individuals' residential histories at each residence-specific asbestos concentration multiplied by the duration during the potential exposure period of 1957-1975 (crocidolite). We observed an increasing, dose-dependent risk of mesothelioma death associated with neighborhood exposure, demonstrating that ORs in the highest quintile category were 21.4 (95% confidence interval [CI] 5.8-79.2) for all, 23.7 (95% CI 3.8-147.2) for males, and 26.0 (95% CI 2.8-237.5) for females compared to the lowest quintile, respectively. A quantitative assessment for risk of mesothelioma deaths, adjusting for occupational and non-occupational exposures separately, showed a dose-dependent association with neighborhood exposure and no substantial gender differences in magnitude.

A COL4A1 variant in a neonate with multiple intracranial hemorrhages and congenital cataracts.

A 2-day-old neonate presented with seizures, multiple intracranial hemorrhages, and bilateral congenital cataracts. Targeted next-generation sequencing of the collagen type IV alpha 1 chain (COL4A1) gene revealed a heterozygous de novo missense variant (NM_001845.6:c.2291G>A/p.Gly764Asp). This missense variant adds to the compendium of COL4A1 variants and is associated with a COL4A1-related disorder.

Deep learning model for the automatic classification of COVID-19 pneumonia, non-COVID-19 pneumonia, and the healthy: a multi-center retrospective study.

This retrospective study aimed to develop and validate a deep learning model for the classification of coronavirus disease-2019 (COVID-19) pneumonia, non-COVID-19 pneumonia, and the healthy using chest X-ray (CXR) images. One private and two public datasets of CXR images were included. The private dataset included CXR from six hospitals. A total of 14,258 and 11,253 CXR images were included in the 2 public datasets and 455 in the private dataset. A deep learning model based on EfficientNet with noisy student was constructed using the three datasets. The test set of 150 CXR images in the private dataset were evaluated by the deep learning model and six radiologists. Three-category classification accuracy and class-wise area under the curve (AUC) for each of the COVID-19 pneumonia, non-COVID-19 pneumonia, and healthy were calculated. Consensus of the six radiologists was used for calculating class-wise AUC. The three-category classification accuracy of our model was 0.8667, and those of the six radiologists ranged from 0.5667 to 0.7733. For our model and the consensus of the six radiologists, the class-wise AUC of the healthy, non-COVID-19 pneumonia, and COVID-19 pneumonia were 0.9912, 0.9492, and 0.9752 and 0.9656, 0.8654, and 0.8740, respectively. Difference of the class-wise AUC between our model and the consensus of the six radiologists was statistically significant for COVID-19 pneumonia (p value = 0.001334). Thus, an accurate model of deep learning for the three-category classification could be constructed; the diagnostic performance of our model was significantly better than that of the consensus interpretation by the six radiologists for COVID-19 pneumonia.

Dissemination of Chest Compression-Only Cardiopulmonary Resuscitation by Bystanders for Out-of-Hospital Cardiac Arrest in Students: A Nationwide Investigation in Japan.

We aimed to investigate how the types of bystander-initiated cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) among students have changed recently. We also determined the association between two types of bystander-CPRs (i.e., chest compression-only CPR [CCCPR] and conventional CPR with rescue breathing [CCRB]) and survival after OHCA. From a nationwide registry of pediatric OHCAs occurring in school settings in Japan, the data of 253 non-traumatic OHCA patients (elementary, junior high, and high school/technical college students) receiving bystander-CPR between April 2008 and December 2017 were analyzed. Multivariable logistic regression analysis was conducted to assess the impact of different types of bystander-CPR on 30-day survival with favorable neurological outcomes. The proportion of patients receiving CCCPR increased from 25.0% during 2008-2009 to 55.3% during 2016-2017 (p for trend < 0.001). Overall, 53.2% (50/94) of patients receiving CCCPR and 46.5% (74/159) of those receiving CCRB survived for 30 days with favorable neurological outcomes. Multivariable analysis showed no significant difference in outcomes between the two groups (adjusted odds ratio: 1.23, 95% confidence interval: 0.67-2.28). In this setting, CCCPR is a common type of bystander-CPR for OHCA in students, and the effectiveness of CCCPR and CCRB on survival outcomes seems comparable.

A Nationwide Epidemiological Survey of Adolescent Patients With Diverse Symptoms Similar to Those Following Human Papillomavirus Vaccination: Background Prevalence and Incidence for Considering Vaccine Safety in Japan.

BACKGROUND: Since June 2013, Japan has suspended proactive recommendation of human papillomavirus (HPV) vaccination due to self-reported diverse symptoms, including pain and motor dysfunction, as possible serious adverse events following immunization. Although these symptoms may be seen in adolescents without HPV vaccination, their frequency, taking into account disease severity, has not been examined. METHODS: A two-stage, descriptive, nationwide epidemiological survey was conducted in 2016, with a 6-month target period from July 1 to December 31, 2015, to estimate the prevalence and incidence of diverse symptoms among Japanese adolescents without HPV vaccination. Participants were 11,037 medical departments in hospitals selected nationwide by stratified random sampling. Eligible patients had to satisfy four criteria: (1) aged 12-18 years upon visiting hospital; (2) having at least one of four symptoms/disorders (pain or sensory dysfunction, motor dysfunction, autonomic dysfunction, or cognitive impairment); (3) symptoms/disorders persisting for at least 3 months; and (4) both criteria (2) and (3) influence attendance at school or work. We then extracted data of patients with diverse symptoms similar to those after HPV vaccination while considering opinions of doctors in charge. RESULTS: Estimated 6-month period prevalence of diverse symptoms among girls aged 12-18 years without HPV vaccination was 20.2 per 100,000. Annual incidence was estimated to be 7.3 per 100,000. CONCLUSION: Adolescent Japanese girls without HPV vaccination also visited hospitals with diverse symptoms similar to those following HPV vaccination. Our findings predict the medical demands for coincident diverse symptoms, which are temporally associated with but not caused by HPV vaccination of Japanese adolescents.

Low-intensity cigarette smoking and mortality risks: a pooled analysis of prospective cohort studies in Japan.

BACKGROUND: Increasing proportions of smokers in Japan smoke <10 cigarettes per day (CPD). Yet, the health risks of low-intensity smoking in Asia are poorly understood. METHODS: We performed a pooled analysis of 410 294 adults from nine population-based prospective cohort studies participating in the Japan Cohort Consortium. Cigarette-use data were collected at each study baseline in 1983-1994. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality were calculated using multivariable-adjusted Cox regression by CPD among current smokers and by age at cessation among former smokers, with never smokers as the referent group. Pooled HRs and CIs were computed using a random-effect model. RESULTS: The smoking prevalence was 54.5% in men and 7.4% in women. About 15.5% of male and 50.4% of female current smokers smoked 1-10 CPD (low-intensity). Both male and female low-intensity smokers had higher all-cause mortality risks than never smokers. Risks were further higher with increasing CPD in a dose-response manner. HRs (95% CIs) were 1.27 (0.97-1.66), 1.45 (1.33-1.59) and 1.49 (1.38-1.62) for 1-2, 3-5 and 6-10 CPD, respectively, in men; 1.28 (1.01-1.62), 1.49 (1.34-1.66) and 1.68 (1.55-1.81) for 1-2, 3-5 and 6-10 CPD, respectively, in women. Similar associations were observed for smoking-related causes of death. Among former low-intensity smokers, younger age at cessation was associated with lower mortality risk. CONCLUSIONS: Smoking very low amounts was associated with increased mortality risks in Japan. All smokers should quit, even if they smoke very few CPD.

Impact of reproductive factors on breast cancer incidence: Pooled analysis of nine cohort studies in Japan.

Prior studies reported the association of reproductive factors with breast cancer (BC), but the evidence is inconsistent. We conducted a pooled analysis of nine cohort studies in Japan to evaluate the impact of six reproductive factors (age at menarche/age at first birth/number of births/age at menopause/use of female hormones/breastfeeding) on BC incidence. We conducted analyses according to menopausal status at the baseline or at the diagnosis. Hazard ratio (HR) and 95% confidence interval (CI) were estimated by applying Cox proportional-hazards model in each study. These hazard ratios were integrated using a random-effects model. Among 187,999 women (premenopausal: 61,113, postmenopausal: 126,886), we observed 873 premenopausal and 1,456 postmenopausal cases. Among premenopausal women, use of female hormones significantly increased BC incidence (HR: 1.53 [1.04-2.25]). Although P value for trend was not significant for age at first birth and number of births (P for trend: 0.15 and 0.30, respectively), women giving first birth at ages ≥36 experienced significantly higher BC incidence than at ages 21-25 years, and women who had ≥2 births experienced significantly lower BC incidence than nulliparous women. Among postmenopausal women, more births significantly decreased BC incidence (P for trend: 0.03). Although P value for trend was not significant for age at first birth and age at menopause (P for trend: 0.30 and 0.37, respectively), women giving first birth at ages 26-35 years experienced significantly higher BC incidence than at ages 21-25 years, and women with age at menopause: ≥50 years experienced significantly higher BC incidence than age at menopause: ≤44 years. BC incidence was similar according to age at menarche or breastfeeding history among both premenopausal and postmenopausal women. In conclusion, among Japanese women, use of female hormones increased BC incidence in premenopausal women, and more births decreased BC incidence in postmenopausal women.

Mortality of Japanese Olympic athletes in 1964 Tokyo Olympic Games.

OBJECTIVES: To compare the mortality of Japanese athletes in the 1964 Tokyo Olympic Games with that of the Japanese population, and to elucidate factors associated with their mortality. METHODS: We obtained from the Japan Sport Association study subjects' biographical information, information on lifestyles and medical data. Missing data were obtained from online databases. Standardised mortality ratio (SMR) was calculated to compare athletes' mortality with the Japanese population. Cox proportional hazards model was applied to estimate the HR for each category of body mass index (BMI), smoking history and handgrip strength. This analysis was limited to male athletes due to the small number of female athletes. RESULTS: Among 342 (283 men, 59 women) athletes, deaths were confirmed for 70 (64 men, 6 women) athletes between September 1964 and December 2017. Total person years was 15 974.8, and the SMR was 0.64 (95% CI 0.50 to 0.81). Multivariate analysis performed on 181 male athletes. Mortality was significantly higher for BMI≥25 kg/m2 than for 21-23 kg/m2 (HR: 3.03, 95% CI 1.01 to 9.07). We found no statistically significant associations between smoking history and mortality; the HR (95% CI) for occasional and daily smokers were 0.82 (0.26 to 2.57) and 1.30 (0.55 to 3.03) compared with never smokers. We also found no statistically significant associations between handgrip strength and mortality (P for trend: 0.51). CONCLUSION: Japanese athletes in the 1964 Tokyo Olympic Games lived longer than the Japanese population. BMI≥25 kg/m2 was associated with higher mortality, but smoking history and handgrip strength were not associated with mortality.

Correction: A novel mutation in the SLCO2A1 gene, encoding a prostaglandin transporter, induces chronic enteropathy.

[This corrects the article DOI: 10.1371/journal.pone.0241869.].

Alcohol consumption and breast cancer risk in Japan: A pooled analysis of eight population-based cohort studies.

Although alcohol consumption is reported to increase the incidence of breast cancer in European studies, evidence for an association between alcohol and breast cancer in Asian populations is insufficient. We conducted a pooled analysis of eight large-scale population-based prospective cohort studies in Japan to evaluate the association between alcohol (both frequency and amount) and breast cancer risk with categorization by menopausal status at baseline and at diagnosis. Estimated hazard ratios (HR) and 95% confidence intervals were calculated in the individual cohorts and combined using random-effects models. Among 158 164 subjects with 2 369 252 person-years of follow-up, 2208 breast cancer cases were newly diagnosed. Alcohol consumption had a significant association with a higher risk of breast cancer in both women who were premenopausal at baseline (regular drinker compared to nondrinker: HR 1.37, 1.04-1.81, ≥23 g/d compared to 0 g/d: HR 1.74, 1.25-2.43, P for trend per frequency category: P = .017) and those who were premenopausal at diagnosis (≥23 g/d compared to 0 g/d: HR 1.89, 1.04-3.43, P for trend per frequency category: P = .032). In contrast, no significant association was seen in women who were postmenopausal at baseline or at diagnosis, despite a substantial number of subjects and long follow-up period. Our results revealed that frequent and high alcohol consumption are both risk factors for Asian premenopausal breast cancer, similarly to previous studies in Western countries. The lack of a clear association in postmenopausal women in our study warrants larger investigation in Asia.

Human papillomavirus vaccine to prevent cervical intraepithelial neoplasia in Japan: A nationwide case-control study.

Cervical cancer remains among the most common cancers in women worldwide and can be prevented by vaccination. The Ministry of Health, Labour and Welfare of Japan suspended active recommendation of regular human papillomavirus (HPV) vaccines in 2013 because of various symptoms including chronic pain and motor impairment. This nationwide case-control study from April 2013 to March 2017 targeted women aged 20-24 years old at cervical screening. We compared HPV vaccination exposure between those with abnormal and normal cytology. Abnormal cytology was classified based on the results of histological test and we calculated the odds ratio (OR) and 95% confidence interval (CI) of the above endpoints and vaccination exposure using the conditional logistic regression model and estimated vaccine effectiveness using the formula (1 - OR) × 100. A total of 2483 cases and 12 296 controls (one-to-five matching) were eligible in 31 municipalities in Japan. The distribution of histological abnormalities among cases was 797 CIN1 (including dysplasia) (32.1%), 165 CIN2 (6.7%), 44 CIN3 (1.8%), and eight squamous cell carcinoma (SCC) (0.3%). The OR of HPV vaccination compared with no vaccination for abnormal cytology, CIN1+, CIN2+, and CIN3+ versus controls was 0.42 (95% CI, 0.34-0.50), 0.42 (95% CI, 0.31-0.58), 0.25 (95% CI, 0.12-0.54), and 0.19 (95% CI, 0.03-1.15), respectively, equating to a vaccine effectiveness of 58.5%, 57.9%, 74.8%, and 80.9%, respectively. Eight patients had SCC, none was vaccinated. This nationwide case-control study in Japan demonstrated a substantial risk reduction in abnormal cytology and CIN among women who did versus those who did not receive HPV vaccination.

Smoking and colorectal cancer: A pooled analysis of 10 population-based cohort studies in Japan.

Smoking has been consistently associated with the risk of colorectal cancer (CRC) in Western populations; however, evidence is limited and inconsistent in Asian people. To assess the association of smoking status, smoking intensity and smoking cessation with colorectal risk in the Japanese population, we performed a pooled analysis of 10 population-based cohort studies. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox's proportional hazards model and then pooled using a random-effects model. Among 363 409 participants followed up for 2 666 004 person-years, 9232 incident CRCs were identified. In men, compared with never smokers, ever smokers showed higher risk of CRC. The HRs (95% CI) were 1.19 (1.10-1.29) for CRC, 1.19 (1.09-1.30) for colon cancer, 1.28 (1.13-1.46) for distal colon cancer and 1.21 (1.07-1.36) for rectal cancer. Smoking was associated with risk of CRC in a dose-response manner. In women, compared with never smokers, ever smokers showed increased risk of distal colon cancer (1.47 [1.19-1.82]). There was no evidence of a significant gender difference in the association of smoking and CRC risk. Our results confirm that smoking is associated with an increased risk of CRC, both overall and subsites, in Japanese men and distal colon cancer in Japanese women.

A novel mutation in the SLCO2A1 gene, encoding a prostaglandin transporter, induces chronic enteropathy.

Chronic enteropathy associated with SLCO2A1 gene (CEAS) is caused by loss-of-function mutations in SLCO2A1, which encodes a prostaglandin (PG) transporter. In this study, we report a sibling case of CEAS with a novel pathogenic variant of the SLCO2A1 gene. Compound heterozygous variants in SLCO2A1 were identified in an 8-year-old boy and 12-year-old girl, and multiple chronic nonspecific ulcers were observed in the patients using capsule endoscopy. The splice site mutation (c.940 + 1G>A) of the paternal allele was previously reported to be pathogenic, whereas the missense variant (c.1688T>C) of the maternal allele was novel and had not yet been reported. The affected residue (p.Leu563Pro) is located in the 11th transmembrane domain (helix 11) of SLCO2A1. Because SLCO2A1 mediates the uptake and clearance of PGs, the urinary PG metabolites were measured by liquid chromatography coupled to tandem mass spectrometry. The urinary tetranor-prostaglandin E metabolite levels in the patients were significantly higher than those in unaffected individuals. We established cell lines with doxycycline-inducible expression of wild type SLCO2A1 (WT-SLCO2A1) and the L563P mutant. Immunofluorescence staining showed that WT-SLCO2A1 and the L563P mutant were dominantly expressed on the plasma membranes of these cells. Cells expressing WT-SLCO2A1 exhibited time- and dose-dependent uptake of PGE2, while the mutant did not show any uptake activity. Residue L563 is very close to the putative substrate-binding site in SLCO2A1, R561 in helix 11. However, in a molecular model of SLCO2A1, the side chain of L563 projected outside of helix 11, indicating that L563 is likely not directly involved in substrate binding. Instead, the substitution of Pro may twist the helix and impair the transporter function. In summary, we identified a novel pathogenic variant of SLCO2A1 that caused loss-of-function and induced CEAS.

Dietary Acrylamide Intake and the Risk of Liver Cancer: The Japan Public Health Center-Based Prospective Study.

Acrylamide has been studied for its carcinogenicity in experimental animals, causing tumors at several organ sites, and has been considered probably carcinogenic to humans as well. Given the small number of epidemiological studies that have been conducted, it is still uncertain whether the consumption of acrylamide is associated with liver cancer. Therefore, we investigated a study to determine the possible relationship between acrylamide intake and the risk of developing liver cancer in the Japanese population. A total of 85,305 participants, from the Japan Public Health Center-based Prospective Study, who provided a validated food-frequency questionnaire were enrolled between 1995 and 1998. During a median of 16.0 years follow-up, 744 new liver cancer cases were identified. Compared to the lowest tertile of acrylamide consumption (<4.8 µg/day), the multivariate hazard ratio (HR) for the highest tertile (≥7.6 µg/day) was 0.79 (95% confidence interval [CI] = 0.65-0.95) for liver cancer using multivariable model 1, adjusted for smoking status, body mass index (BMI), physical activity, medical history, and alcohol consumption; whereas the inverse relationship disappeared after additionally adjusting for coffee consumption in multivariable model 2 with HR of 1.08 (95% CI = 0.87-1.34) for the highest tertile. The effect of dietary acrylamide intake on the risk of liver cancer was not observed in the Japanese population.

Incidence, characteristics, and outcomes of pediatric out-of-hospital cardiac arrest in nursery schools and kindergartens in Japan.

BACKGROUND: A better understanding of the epidemiology of pediatric out-of-hospital cardiac arrest (OHCA) occurring in nursery schools and kindergartens is indispensable to establish an evidence-based strategy for prevention and improved outcomes. This study aimed to describe the incidence, characteristics, and outcomes of pediatric OHCAs that occurred in certified nursery schools and kindergartens. METHODS: Stop and Prevent cardIac aRrest, Injury, and Trauma in Schools (SPIRITS) is a study to construct and analyze a nationwide registry of pediatric OHCAs occurring in school settings in Japan. Using data from the SPIRITS registry, we assessed the incidence, characteristics, and outcomes of pediatric OHCAs that occurred in certified nursery schools/kindergartens between April 2008 and December 2016. RESULTS: During the study period, 37 OHCA patients (31 in certified nursery schools and 6 in kindergartens) were confirmed. The overall incidence rate was 0.13 per 100,000 children per year. Among 37 patients, 57% (21/37) had an OHCA while napping and 35% (13/37) experienced OHCA that was witnessed by bystanders. Although public-access automated external defibrillator pads were applied by bystanders in 24% (9/37) of cases, only 1 patient actually received defibrillation. Overall, the proportion of 1-month survival with favorable neurological outcomes after OHCA was 19% (7/37). Among those with OHCA of non-medical origins, 60% (3/5) of patients experienced arrest caused by suffocation, 60% (3/5) by drowning, and 100% (1/1) by head injury. In contrast, no patient had 1-month favorable neurological outcomes among those with OHCA of medical origins such as presumed cardiac origin (0/17), sudden infant death syndrome (0/6), acute viral myocarditis (0/1), respiratory disease (0/1), and ventricular fibrillation (0/1). CONCLUSIONS: In this population, the majority of pediatric OHCAs occurring in certified nursery schools/kindergartens had non-ventricular fibrillation rhythm, and their outcomes after OHCA of medical origin were poor.

The Effect of Chemotherapy on Stroke Risk in Cancer Patients.

BACKGROUND: Chemotherapy may be a cause of cancer-associated stroke, but whether it increases stroke risk remains uncertain. We investigated how chemotherapy affects stroke risk in cancer patients. METHODS: Of 27,932 patients in a hospital-based cancer registry (which contains clinical data on all patients treated for cancer at Osaka University Hospital) screened between 2007 and 2015, medical records of 19,006 patients with complete data were investigated. A validated algorithm was used to identify stroke events within 2 years of cancer diagnosis. Patients were divided based on whether their initial treatment plan included chemotherapy. The association between chemotherapy and stroke was analyzed using the Kaplan-Meier method and stratified Cox regression. RESULTS: Of 19,006 patients, 5,887 (31%) were in the chemotherapy group. Stroke occurred in 44 (0.75%) and 51 (0.39%) patients in the chemotherapy and nonchemotherapy group, respectively. Kaplan-Meier curve analysis showed that patients in the chemotherapy group had a higher stroke risk than those in the nonchemotherapy group (hazard ratio [HR] 1.84; 95% confidence interval [CI] 1.23-2.75). However, this difference was insignificant after adjustment for cancer status using inverse probability of treatment weighting with propensity scores (HR 1.20; 95% CI 0.76-1.91). Similarly, in the stratified Cox regression model, chemotherapy was not associated with stroke after adjustment for cancer status (HR 1.26; 95% CI 0.78-2.03). CONCLUSION: In our study, the elevated stroke risk in cancer patients who received chemotherapy was presumably due to advanced cancer stage; chemotherapy was not associated with the increased risk of stroke.

Analysis of the genetic background associated with sporadic periodic paralysis in Japanese patients.

Periodic paralysis (PP) is a rare disease caused by abnormal excitability of the sarcolemma, resulting in the episodic weakness in extremities. Two major subtypes have been identified: primary/familial PP showing Mendelian inheritance of a mutation in the ion channel genes expressed in skeletal muscle, and secondary/sporadic PP which does not show Mendelian inheritance. Thyrotoxic periodic paralysis (TPP) contributes to the majority of secondary PP cases in Asians and Latin Americans, suggesting that genetic factors may underlie the pathogenesis. In contrast, sporadic periodic paralysis (SPP) has no familial history and no secondary factors. The genetic features associated with SPP in Japanese patients remain unexplored. Here, we investigate whether nine single nucleotide variants (SNVs), rs623011, rs312691, rs393743, rs312692, rs312736, rs992072, rs312732, rs723498, and rs312707, found in TPP and/or SPP in other Asian populations are also associated with Japanese SPP cases. The study cohort included 43 Japanese periodic paralysis patients with no mutations in causative genes (SCN4A, CACNA1S, and KCNJ2), no myotonia, and with euthyroid function. The results showed disease susceptibility for all nine SNVs in our Japanese SPP cohort. One of them, rs312691, was newly confirmed to show susceptibility to SPP. Our results suggest the genetic background underlies periodic paralysis.