Mental health symptoms among dependent contractors in Korea: a cross-sectional study based on the Fifth Korean Working Condition Survey.

Background: Recently, there has been a call to improve the holistic welfare of dependent contractors (DCs). Thus, our study examined the relationship between DCs and mental health symptoms and how this relationship was modified by age, sex, and income status of workers. Methods: A total of 27,980 workers from the Fifth Korean Working Conditions Survey are included in our study. The participants who reported having depression or anxiety over the last 12 months are defined those who had mental health symptoms. We performed exact matching for age group and sex, followed by conditional logistic regression with survey weights. Finally, stratified analyses by age, sex and income level were conducted. Results: DCs were found to be at increased risk of depression/anxiety compared to other workers. The odds ratio (OR) is 1.52 (95% confidence interval [CI]: 1.06-2.17). In the stratified analyses, vulnerable groups were middle-aged (OR [95% CI]: 1.68 [1.10-2.54]), female (OR [95% CI]: 1.85 [1.20-2.84]), and low-income (OR [95% CI]: 3.18 [1.77-5.73]) workers. Conclusions: Our study's results reinforce those of other studies that show that DCs are at greater risk of experiencing mental health issues than other workers and that and this risk is greater for middle-aged, female, and low-income workers. These results suggest that appropriate policy efforts should be made to improve the psychological well-being of DCs.

Comparison of the risks of occupational diseases, avoidable hospitalization, and all-cause deaths between firefighters and non-firefighters: A cohort study using national health insurance claims data.

Objectives: National Health Insurance claims data were used to compare the incidence of occupational diseases, avoidable hospitalization, and all-cause death standardized incidence ratio and hazard ratio between firefighters and non-firefighters. Methods: The observation period of the study was from 2006 to 2015 and a control group (general workers and national and regional government officers/public educational officers) and a firefighter group was established. The dependent variables were occupational diseases, avoidable hospitalization (AH), and all-cause death. The analysis was conducted in three stages. First, the standardized incidence ratios were calculated using the indirect standardization method to compare the prevalence of the disease between the groups (firefighter and non-firefighter groups). Second, propensity score matching was performed for each disease in the control group. Third, the Cox proportional hazards model was applied by matching the participants. Results: The standardized incidence ratio and Cox regression analyses revealed higher rates of noise-induced hearing loss, ischemic heart disease, asthma, chronic obstructive pulmonary disease, cancer, back pain, admission due to injury, mental illness, depression, and AH for firefighters than general workers. Similarly, the rates of noise-induced hearing loss, ischemic heart disease, asthma, chronic obstructive pulmonary disease, back pain, admission due to injury, mental illness, depression, and AH were higher in the firefighter group than in the national and regional government officer/public educational officer group. Conclusions: The standardized incidence ratios and hazard ratios for most diseases were high for firefighters. Therefore, besides the prevention and management of diseases from a preventive medical perspective, management programs, including social support and social prescriptions in the health aspect, are needed.

The Role of Processed Aloe vera Gel in Intestinal Tight Junction: An In Vivo and In Vitro Study.

Leaky gut is a condition of increased paracellular permeability of the intestine due to compromised tight junction barriers. In recent years, this affliction has drawn the attention of scientists from different fields, as a myriad of studies prosecuted it to be the silent culprit of various immune diseases. Due to various controversies surrounding its culpability in the clinic, approaches to leaky gut are restricted in maintaining a healthy lifestyle, avoiding irritating factors, and practicing alternative medicine, including the consumption of supplements. In the current study, we investigate the tight junction-modulating effects of processed Aloe vera gel (PAG), comprising 5-400-kD polysaccharides as the main components. Our results show that oral treatment of 143 mg/kg PAG daily for 10 days improves the age-related leaky gut condition in old mice, by reducing their individual urinal lactulose/mannitol (L/M) ratio. In concordance with in vivo experiments, PAG treatment at dose 400 µg/mL accelerated the polarization process of Caco-2 monolayers. The underlying mechanism was attributed to enhancement in the expression of intestinal tight junction-associated scaffold protein zonula occludens (ZO)-1 at the translation level. This was induced by activation of the MAPK/ERK signaling pathway, which inhibits the translation repressor 4E-BP1. In conclusion, we propose that consuming PAG as a complementary food has the potential to benefit high-risk patients.

Therapeutic Evaluation of Synthetic Peucedanocoumarin III in an Animal Model of Parkinson's Disease.

The motor and nonmotor symptoms of Parkinson's disease (PD) correlate with the formation and propagation of aberrant α-synuclein aggregation. This protein accumulation is a pathological hallmark of the disease. Our group recently showed that peucedanocoumarin III (PCIII) possesses the ability to disaggregate ß sheet aggregate structures, including α-synuclein fibrils. This finding suggests that PCIII could be a therapeutic lead compound in PD treatment. However, the translational value of PCIII and its safety information have never been explored in relevant animal models of PD. Therefore, we first designed and validated a sequence of chemical reactions for the large scale organic synthesis of pure PCIII in a racemic mixture. The synthetic PCIII racemate facilitated clearance of repeated ß sheet aggregate (ß23), and prevented ß23-induced cell toxicity to a similar extent to that of purified PCIII. Given these properties, the synthetic PCIII's neuroprotective function was assessed in 6-hydroxydopamine (6-OHDA)-induced PD mouse models. The PCIII treatment (1 mg/kg/day) in a 6-OHDA-induced PD mouse model markedly suppressed Lewy-like inclusions and prevented dopaminergic neuron loss. To evaluate the safety profiles of PCIII, high dose PCIII (10 mg/kg/day) was administered intraperitoneally to two-month-old mice. Following 7 days of PCIII treatment, PCIII distributed to various tissues, with substantial penetration into brains. The mice that were treated with high dose PCIII had no structural abnormalities in the major organs or neuroinflammation. In addition, high dose PCIII (10 mg/kg/day) in mice had no adverse impact on motor function. These findings suggest that PCIII has a relatively high therapeutic index. Given the favorable safety features of PCIII and neuroprotective function in the PD mouse model, it may become a promising disease-modifying therapy in PD to regulate pathogenic α-synuclein aggregation.

Injury epidemiology of workers by age, sex and industrial classification using the medical claim data of National Health Insurance in South Korea, 2012-2015: a population-based retrospective study.

OBJECTIVES: This study aimed to evaluate the risk of inpatient hospitalisation for all-cause injuries, according to age, sex and industrial classification (IC) in South Korea. DESIGN: A population-based retrospective study. SETTING AND PARTICIPANTS: Data from the National Health Insurance Database on medical claims for the entire population of South Korean workers aged 25-59 years from January 2012 to December 2015 were retrieved. We observed 30 900 712 person-years (63.1%) in male workers and 18 105 272 person-years (36.9%) in female workers. MAIN OUTCOME MEASURES: The inpatient hospitalisation for all-cause injury was defined as admission for which the principal diagnosis included S00-T98 in the Korean version of International Classification of Diseases-10 codes. RESULTS: Of 788 575 hospitalisations for all-cause injuries from 2012 to 2015, there were 565 107 cases in male workers (1 828.8 per 100 000 person-years) and 223 468 cases in female workers (1 234.3 per 100 000 person-years). The top five ICs with hospitalisation rate ratios (HRR) for all-cause injuries in both sexes compared with the financial intermediation IC included agriculture, hunting and forestry (HRR (95% CI); male: 2.09 (1.98 to 2.20); female: 1.53 (1.40 to 1.67)); mining and quarrying (male: 2.05 (1.92 to 2.19); female: 1.54 (1.27 to 1.87)) and fishing (male: 1.68 (1.57 to 1.80); female: 1.71 (1.51 to 1.93)). A U-shaped relationship occurred between age and risk for injuries in males; however, only a linear relationship was shown in females, regardless of IC. CONCLUSIONS: The risk of injures varied by IC. The workers in agriculture, hunting, forestry, mining, quarrying and fishing were more vulnerable to injuries. The risk for injuries were higher among men and the age effect on this risk differed by sex. Thus, policy makers need to consider specific measures for prevention of injuries according to age, sex and IC.