The inflammatory response to simulated day and night emergency alarm mobilisations

Differential effects of acute and chronic hydrocortisone treatment on pyroptosis

Pyroptosis is a programmed and inflammation-inducing cell death that occurs predominantly in macrophages. It is characterized by the inflammasome-mediated activation of caspase-1, leading to cell lysis. During pyroptosis, pro-inflammatory mediators such as IL-1β are released extracellularly to further recruit and activate other immune cells. Thus, pyroptosis plays a crucial role in the prevention of the spread of pathogens. The clinically applied synthetic glucocorticoid, hydrocortisone (HC), has strong immunoregulatory properties. It may act as an immunosuppressive agent by negatively regulating pro-inflammatory gene transcription but has also shown immune-sensitizing properties. The conditions that determine the immunosuppressive or immune-sensitizing actions of HC during an infection are not fully clear. We hypothesized that the outcome may differ depending on the onset and duration of its administration. Therefore, we investigated the impact of acute (treatment upon infection) and chronic (24 h pre-treatment before infection) HC treatment on pyroptosis induction and execution in THP-1 macrophage-like cells. The focus was on pyroptosis-associated signaling pathways, inflammasome assembly and activation, IL-1β, and cell death. Physiological HC concentration and HC deprivation were used as controls. Compared to the physiological concentration, cells displayed augmented inflammasome activation and IL-1β release following acute HC treatment. Conversely, the whole pyroptosis machinery was suppressed by chronic HC administration. These in vitro investigations demonstrate pro-inflammatory actions of acute HC exposure and the immunosuppressive effects of chronic treatment. These differential effects on pyroptosis emphasize the importance of individualized HC medication in patients upon infection, and suggest the inclusion of IL-1β as a marker for current immune capacities.

The relationship between exposure to environmental noise and risk of atopic dermatitis, asthma, and allergic rhinitis

BACKGROUND

Noise is defined as unwanted sound. It may induce negative emotions and mental health problems and may even lead to increased suicide risk. However, the impact of noise exposure on environmental diseases and disease severity is not well understood. This study aimed to elucidate the association between night-time noise exposure and the prevalence of environmental diseases in South Korea.

METHODS

We conducted an analysis of the Environmental Disease Database provide by the National Health Insurance Service (NHIS) from 2013 to 2017. After spatially interpolating the noise data provided by the National Noise Information System (NNIS), night-time noise values in the district level were obtained by calculating the mean noise values at the administrative district level. The linear regression analyses were performed to test the association between the age-standardized prevalence ratio (SPR) and the night-time noise exposure in the district level.

RESULTS

In areas with high night-time noise exposure (≥55 dB), the SPR for atopic dermatitis and allergic rhinitis were 1.0515 (95 % confidence interval [CI]:1.0508-1.0521) and 1.0202 (95 % CI:1.0201-1.0204), respectively, which were higher than those in the general population. The SPR for environmental diseases, including atopic dermatitis, asthma, and allergic rhinitis, was 1.0104 (95 % CI:1.0103-1.0105). Additionally, a significant linear association was observed between the level of nocturnal noise exposure and the total hospitalization period for atopic dermatitis (β = 399.3, p < 0.01).

CONCLUSION

We provide evidence of a significant association between night-time environmental noise and environmental diseases, particularly atopic dermatitis and allergic rhinitis. Furthermore, we observed a significant linear association between night-time noise exposure and the severity of atopic dermatitis.

Occupational and Environmental Noise Exposure and Extra-Auditory Effects on Humans: A Systematic Literature Review

Noise is a common harmful factor in our work and the environment. Most studies have investigated the auditory effects of noise exposure; however, few studies have focused on the extra-auditory effects of exposure to occupational or environmental noise. This study aimed to systematically review published studies on the extra-auditory effects of noise exposure. We reviewed literature from PubMed and Google Scholar databases up to July 2022, using the Patient, Intervention, Comparison, and Outcome criteria and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify studies that reported extra-auditory effects of occupational or environmental noise exposure. Studies were evaluated utilizing validated reporting tools (CONSORT, STROBE) appropriate to study design. A total of 263 articles were identified, of which 36 were finally selected and reviewed. Upon conducting a review of the articles, exposure to noise can elicit a variety of extra-auditory effects on humans. These effects include circulatory effects linked to higher risk of cardiovascular disease and decreased endothelial function, nervous system effects correlated with sleep disturbance, cognitive impairment, and mental health problems, immunological and endocrinal effects connected to increased physiological stress response and metabolic disorders, oncological and respiratory effects associated with an elevated risk of acoustic neuroma and respiratory disorders, gastrointestinal effects linked to an increased risk of gastric or duodenal ulcer, and obstetric effects connected to the risk of preterm birth. Our review suggests that there are numerous extra-auditory effects of noise exposure on human, and further investigations are needed to fully understand these effects.

A meal enriched in saturated fat acutely impairs cognitive performance in obese men

BACKGROUND

Diets chronically high in saturated fat (SFA) associate with obesity and insulin resistance (IR), which in turn associate with cognitive decline and dementia. However, understanding how acute SFA consumption influences cognition is less clear despite short-term SFA-enriched diets inducing whole-body IR. We examined how consuming meals enriched with SFA or monounsaturated fat (MUFA) acutely influence cognitive function in lean and obese men. We hypothesized that greater diet-induced IR following a SFA-enriched meal would associate with decreased cognitive performance.

METHODS

Twelve lean and 12 obese males ingested meals containing no fat (CTL), enriched with SFA, or enriched with MUFA in a single-blind, randomized fashion. Cognitive testing and blood sampling were performed pre- and 2 h post-meal. Oral glucose tolerance (OGTT) and body composition were also assessed.

RESULTS

At baseline, fasting glucose, insulin, HOMA-IR, triglyceride, IL-6, and 2-hr glucose during an OGTT were higher in obese men (p < 0.001), while executive function (Stroop Test and Trail Making Test B-A) and working memory (Digit Span Test) were lower in obese men (p < 0.05). In response to the CTL and MUFA-enriched, no differences in cognitive measures were observed in lean or obese subjects. Following a SFA-enriched meal, obese subjects scored worse during cognitive testing (Stroop Test, Trail Making Test B-A, and Digit Span Test) compared to pre-meal scores (p < 0.05). These impairments in cognitive testing scores following the SFA-enriched meal associated with increased HOMA-IR (p < 0.01) and decreased plasma IL-6 (p < 0.05). No changes in cognitive function were observed in lean subjects following a SFA-enriched meal.

CONCLUSIONS

These data demonstrate that cognitive performance of obese men acutely worsens following a high-SFA meal. Reductions in cognitive performance associated with increased IR, suggesting that diet-induced IR may acutely decrease cognitive function.