Search

SARS-CoV-2 causes profound changes in the sense of smell, including total smell loss. Although these alterations are often transient, many patients with COVID-19 exhibit olfactory dysfunction that lasts months to years. Although animal and human autopsy studies have suggested mechanisms driving acute anosmia, it remains unclear how SARS-CoV-2 causes persistent smell loss in a subset of patients. To address this question, we analyzed olfactory epithelial samples collected from 24 biopsies, including from nine patients with objectively quantified long-term smell loss after COVID-19. This biopsy-based approach revealed a diffuse infiltrate of T cells expressing interferon-γ and a shift in myeloid cell population composition, including enrichment of CD207+ dendritic cells and depletion of anti-inflammatory M2 macrophages. Despite the absence of detectable SARS-CoV-2 RNA or protein, gene expression in the barrier supporting cells of the olfactory epithelium, termed sustentacular cells, appeared to reflect a response to ongoing inflammatory signaling, which was accompanied by a reduction in the number of olfactory sensory neurons relative to olfactory epithelial sustentacular cells. These findings indicate that T cell-mediated inflammation persists in the olfactory epithelium long after SARS-CoV-2 has been eliminated from the tissue, suggesting a mechanism for long-term post-COVID-19 smell loss.

Biofouling on marine surfaces causes immense material and financial harm for maritime vessels and related marine industries. Previous reports have shown the effectiveness of amphiphilic coating systems based on poly(dimethylsiloxane) (PDMS) against such marine foulers. Recent studies on biofouling mechanisms have also demonstrated acidic microenvironments in biofilms and stronger adhesion at low-pH conditions. This report presents the design and utilization of amphiphilic polymer coatings with buffer functionalities as an active disruptor against four different marine foulers. Specifically, this study explores both neutral and zwitterionic buffer systems for marine coatings, offering insights into coating design. Overall, these buffer systems were found to improve foulant removal, and unexpectedly were the most effective against the diatom Navicula incerta. [ABSTRACT FROM AUTHOR]

Background: With a rising incidence of cerebrospinal fluid (CSF) leaks, endoscopic endonasal CSF leak repair is increasingly performed. Current approaches utilize a variety of materials including free mucosal grafts and vascularized flaps, but post-op leaks continue to be reported. Steroid-eluting bioabsorbable stents (SES) are used during functional endoscopic sinus surgery for chronic rhinosinusitis to reduce inflammation and scarring while maintaining patency of sinus ostia. Objective: The aim of this study is to assess the feasibility of SES as a graft/flap bolster for endoscopic endonasal CSF leak repair. Methods: This is a retrospective review of patients undergoing endoscopic endonasal CSF leak repair with SES placed as part of the bolster technique at a tertiary care center between January 2019 and May 2022. Age, sex, BMI, comorbid idiopathic intracranial hypertension, pathology, location of CSF leak, intraoperative CSF leak flow, reconstruction type, and presence of post-op CSF leak were recorded. Results: Twelve patients (mean age 52, median BMI 30.9, 58% female) had SES placement as part of the bolster technique. The most common pathology was meningoencephalocele (75%). Reconstruction was performed with either a free mucosal graft (6), or a flap (6). No post-op CSF leaks occurred at a reconstruction site with a stent, and no known complications were reported. All sinusotomies were patent at the last follow-up visit. Conclusions: SES placement as an adjunct to graft and/or flap bolster appears to be safe and feasible during anterior skull base reconstruction and CSF leak repair providing longer term structural support and preserving sinus drainage patency. [ABSTRACT FROM AUTHOR]

The use of ultraviolet-C (UV-C) irradiation in marine biofouling control is a relatively new and potentially disruptive technology. This study examined effects of UV-C exposure on the biofilm-forming diatom, Navicula incerta. UV-C-induced mutations were identified via Illumina HiSeq. A de novo genome was assembled from control sequences and reads from UV-C-exposed treatments were mapped to this genome, with a quantitative estimate of mutagenesis then derived from the frequency of single nucleotide polymorphisms. UV-C exposure increased cyclobutane pyrimidine dimer (CPD) abundance with a direct correlation between lesion formation and fluency. Cellular repair mechanisms gradually reduced CPDs over time, with the highest UV-C fluence treatments having the fastest repair rates. Mutation abundances were, however, negatively correlated with CPD abundance suggesting that UV-C exposure may influence lesion repair. The threshold fluence for CPD formation exceeding CPD repair was >1.27 J cm−2. Fluences >2.54 J cm−2 were predicted to inhibit repair mechanisms. While UV-C holds considerable promise for marine antifouling, diatoms are just one, albeit an important, component of marine biofouling communities. Determining fluence thresholds for other representative taxa, highlighting the most resistant, would allow UV-C treatments to be specifically tuned to target biofouling organisms, whilst limiting environmental effects and the power requirement. [ABSTRACT FROM AUTHOR]