The Korean Society of Otorhinolaryngology-Head and Neck Surgery and Korean Rhinologic Society appointed a guideline development group (GDG) to establish a clinical practice guideline, and the GDG developed a guideline for nasal irrigation for adult patients with chronic rhinosinusitis (CRS). The guideline focuses on knowledge gaps, practice variations, and clinical concerns associated with nasal irrigation. Nasal irrigation has been recommended as the first-line treatment for CRS in various guidelines, and its clinical effectiveness has been demonstrated through a number of studies with robust evidence. However, no guidelines have presented a consistent nasal irrigation method. Several databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers using a predefined search strategy. When insufficient evidence was found, the GDG sought expert opinions and attempted to fill the evidence gap. Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. The committee developed 11 evidence-based recommendations. This guideline focuses on the evidence-based quality improvement opportunities deemed the most important by the GDG. Moreover, the guideline addresses whether nasal lavage helps treat CRS, what type of rinsing solution should be used, and the effectiveness of using additional medications to increase the therapeutic effect.

Hypoxia resulting from occlusion of the sinus ostium is known to be one of the major pathogenic mechanisms of sinusitis. Hypoxia-inducible factor (HIF)-1 is a widely known transcription factor that induces the cellular response to hypoxic conditions and activates the transcription of several genes, including vascular endothelial growth factor (VEGF). We hypothesized that induced permeability caused by hypoxia is a major pathophysiologic mechanism of upper airway diseases, such as sinusitis. The aim of this study was to investigate the mechanism of hypoxia-induced hyperpermeability, which mediates increased paracellular permeability and enhanced microbial invasiveness in the airway epithelium. We show that expression of VEGF mRNA and protein and HIF-1α protein increased as a function of time under hypoxia in normal human nasal epithelial cells. Our results also indicate that VEGF expression was induced by transfection with a mammalian expression vector encoding HIF-1 but down-regulated by transfection with small interfering RNA specific for HIF-1α under hypoxic conditions. Results of a transepithelial permeability assay measuring transepithelial electrical resistance indicated that permeability was increased as a function of time under hypoxia and was rescued by anti-VEGF monoclonal antibody (bevacizumab) and small interfering RNA specific for HIF-1α. We detected up-regulated HIF-1α and VEGF expression in mucosal epithelium samples from patients with sinusitis compared with normal mucosal epithelium using Western blotting and immunohistochemical staining. In conclusion, we suggest that the hypoxia–HIF-1α–VEGF axis plays an important role in hyperpermeability of airway epithelial cells, implying a role in the pathophysiology of upper respiratory tract diseases, such as sinusitis.

Key points: Human nasal cavity samples were collected, and presence of microplastics were evaluated. Microplastics were present, and major types were polyethylene, polyester, acrylic polymer, and polypropylene. Further research is needed regarding microplastics and its clinical impact on human nasal cavity.

Microplastics have been detected in various human organs, and studies on their impact on human health are ongoing. However, few studies have researched microplastics in the cervicovaginal area. In this study, we aimed to assess their presence in human cervicovaginal lavage fluid. This prospective study was conducted at a single tertiary medical center, enrolling 10 participants aged 27–49 years. Human cervicovaginal lavage fluid samples were collected from the patients by a single skilled obstetrician. Raman spectroscopy was used to analyze and characterize microplastic particles detected in the samples. Ninety-one microplastic particles were detected in 10 samples. More than 50% of the microplastic particles were identified in a single patient who regularly used menstrual cups. The mean number of microplastics was 9.10 ± 14.96 per 10 g sample. Most of the microplastics were <50 μm in size, and polypropylene and polystyrene were the most predominant types. Raman analysis detected microplastic particles in human cervicovaginal lavage fluids, suggesting that the human cervicovaginal area is exposed to microplastics. The number of detected particles varied significantly among individuals. This study highlights the need for further research on the effects of microplastics on the female reproductive system using cervicovaginal lavage fluid.