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We conducted a study to characterize the occupational chemical exposure to JP-8 ［a kerosene-based jet fuel used widely for both military and commercial aircraft） and JP-4 （a naphtha – and kerosene-based jet fuel that is used by the Japan Air Self-Defense Force （JASDF）］. The study population included 90 volunteer subjects from JASDF and United States Air Force bases in Japan. The individual exposure to 48 volatile organic compounds （VOCs） was measured in C-130 （a cargo aircraft） flight line crews and non-exposed control subjects （workers in the Yokota and Kadena hospitals）. The individual air samples were collected during a typical work shift using a compact battery-operated personal air sampler with activated charcoal for gaseous VOCs and with a cascade impactor for aerosolized VOCs （diameter:＜6.6µm）. Each collected sample was analyzed by gas chromatography. Subjects in the JP-4 group were mainly exposed to gaseous aromatics and shorter straight-chain alkanes including carcinogenic benzene and neurotoxic hexane, while the subjects in the JP-8 group were exposed to aerosolized alkanes with a longer straight chain such as tridecane. In conclusion, this study revealed the characteristics of chemical exposure according to the fuel type in the flight line environment. The results suggest the health risks associated with each fuel type and the protective measures that should be employed. Aerosolized tridecane or aerosol containing tridecane might be causing the complaints from workers using kerosene-based fuel. None of the subjects were exposed to VOCs at levels exceeding recommended exposure limits.

IgA nephropathy (IgAN) is characterized by mesangial deposition of IgA, C3, and often IgM. We examined the relationship among IgM deposition, clinical features, and renal outcome in IgAN patients who underwent combined treatment of tonsillectomy with steroid pulse therapy (Tx-SP). We retrospectively reviewed 73 IgAN patients treated with Tx-SP from March 2006 to March 2014. The patients were divided into those with moderate (2+) to severe (3+) mesangial IgM deposition (Prominent IgM-positive patients, P-Group) and those with negative (−) to faint (1+) deposition (the “Other” patients, O-Group). Using propensity scores to minimize confounding factors, 11 propensity score-matched patients with O-Group (mO-Group) were compared to 11 P-Group patients. The study outcome was defined as urinary protein grade by urine test strip before Tx-SP and one year after Tx-SP. P-Group patients exhibited an increased severity of proteinuria compared to O-Group (p=0.018) and mO-Group patients (p=0.009) before Tx-SP. After Tx-SP, proteinuria was significantly ameliorated in the P-Group, reaching the same severity recorded in the O-Group (p=0.007) and mO-Group (p=0.021). No significant differences were noted between P-Group and mO-Group in microhematuria, serum creatinine level, and histological severity. Prominent IgM deposition is associated with severe proteinuria in IgAN. However, Tx-SP induces a sufficient reduction in the severity of proteinuria in IgM-positive IgAN.

Although epidemiological evidence has confirmed the role of heavy alcohol consumption as an established risk factor for esophageal, liver, and breast cancers, the molecular mechanisms underlying this effect are not fully understood, particularly with regard to breast cancer. In this study, expression of the retinoic acid early inducible-1 (RAE-1) gene was determined in mice adipocytes. RAE-1 is a ligand of the natural-killer group 2 member D (NKG2D) receptor, which plays a crucial role in tumor immunity. RT-PCR and Western blotting analysis demonstrated that TNF-α treatment induced RAE-1 mRNA and RAE-1 protein expression in adipocytes obtained from differentiated 3T3-F442A cells. Real-time RT-PCR analysis showed that 300 mM ethanol enhanced RAE-1 mRNA expression, which peaked 6 h after administration. In addition, RAE-1 mRNA was detected in visceral adipose tissue obtained from mice. These observations indicate that RAE-1mRNA is expressed in adipocytes and that its expression is enhanced by TNF-α, which has been shown to be induced in adipose tissue by long-term alcohol consumption. Furthermore, ethanol directly enhanced RAE-1 mRNA expression, suggesting that alcohol consumption enhances RAE-1 expression in adipose tissue and might modify tumor immunity. This finding might provide novel insight into the mechanism of alcohol-associated carcinogenesis.

To develop appropriate glaucoma mass screening programs for occupational health among Japanese workers, we estimated the prevalence of glaucoma and the increase rate by age. A total of 10,579 Japanese general workers (men/women = 9292/1287) underwent frequency doubling technology (FDT) perimetry testing. Visual field abnormalities (VFA) were identified by the FDT-based glaucoma screening protocol (FDT-VFA). Subjects with FDT-VFA were ophthalmologically diagnosed and classified as "normal," "glaucomatous VFA" (preperimetric, suspicious, and definitive glaucoma) or "other ocular diseases." Prevalence of FDT-VFA and positive predictive values for "glaucomatous VFA" and "definitive glaucoma" were calculated by five-year age intervals, and then the prevalence of "glaucomatous VFA" and "definitive glaucoma" in each age interval was estimated. Prevalence of "glaucomatous VFA" and "definitive glaucoma" in workers younger than 30 years old was approximately 1.5% and 0.5%, respectively. Interestingly, the increase in prevalence of glaucoma by age was significantly different between workers with and without refractive errors (RE). From ages 30 to 55 years, the estimated prevalence of "definitive glaucoma" linearly increased with a regression coefficient (%/age in years) that was 2.5-fold higher in subjects with RE than in those without RE {regression coefficient = 0.131 [95% confidence interval (CI) = 0.109, 0.152; R2 = 0.980]vs. 0.047 [95% CI = 0.026, 0.068; R2 = 0.869]for subjects with RE vs. those without RE, respectively}. Further, among workers older than 55 years, the prevalence of glaucoma continued increasing in workers with RE, whereas it plateaued in those without RE. From these estimates, we propose that FDT testing should be conducted as follows: 1) once in workers under the age of 30 years, 2) according to both age and the presence of RE in 30-55 years old, and 3) by age only in those over 55 years old.