SUMMARY Microbiome-encoded β-glucuronidase (GUS) enzymes play important roles in human health by metabolizing drugs in the gastrointestinal (GI) tract. The numbers, types and diversity of these proteins in the human GI microbiome, however, remain undefined. We present an atlas of GUS enzymes comprehensive for the Human Microbiome Project GI database. We identify 3,013 total and 279 unique microbiome-encoded GUS proteins clustered into six unique structural categories. We assign their taxonomy, assess cellular localization, reveal the inter-individual variability within the 139 individuals sampled, and discover 112 novel microbial GUS enzymes. A representative in vitro panel of the most common GUS proteins by read abundances highlights structural and functional variabilities within the family, including their differential processing of smaller glucuronides and larger carbohydrates. These data provide a sequencing-to-molecular roadmap for examining microbiome-encoded enzymes essential to human health.

Objectives Respiratory, voice, and swallowing difficulties after severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) may result secondary to upper airway disease from prolonged intubation or mechanisms related to the virus itself. We examined a cohort who presented with new laryngeal complaints following documented SARS‐CoV‐2 infection. We characterized their voice, airway, and/or swallowing symptoms and reviewed the clinical course of their complaints to understand how the natural history of these symptoms relates to COVID‐19 infections. Methods Retrospective review of patients who presented to our department with upper aerodigestive complaints as sequelae of prior infection with, and management of, SARS‐CoV‐2. Results Eighty‐one patients met the inclusion criteria. Median age was 54.23 years (±17.36). Most common presenting symptoms were dysphonia (n = 58, 71.6%), dysphagia/odynophagia (n = 16, 19.75%), and sore throat (n = 9, 11.11%). Thirty‐one patients (38.27%) presented after intubation. Mean length of intubation was 16.85 days (range 1–35). Eighteen patients underwent tracheostomy and were decannulated after an average of 70.69 days (range 23–160). Patients with history of intubation were significantly more likely than nonintubated patients to be diagnosed with a granuloma (8 vs. 0, respectively, p < .01). Fifty patients (61.73%) were treated for SARS‐CoV‐2 without requiring intubation and were significantly more likely to be diagnosed with muscle tension dysphonia (19 vs. 1, p < .01) and laryngopharyngeal reflux (18 vs. 1, p < .01). Conclusion In patients with persistent dyspnea, dysphonia, or dysphagia after recovering from SARS‐CoV‐2, early otolaryngology consultation should be considered. Accurate diagnosis and prompt management of these common underlying etiologies may improve long‐term patient outcomes. Level of evidence 4

Mitotane is the only drug approved for the therapy of adrenocortical carcinoma (ACC). Its clinical use is limited by the occurrence of relapse during therapy. To investigate the underlying mechanisms in vitro, we here generated mitotane-resistant cell lines. After long-term pulsed treatment of HAC-15 human adrenocortical carcinoma cells with 70 µM mitotane, we isolated monoclonal cell populations of treated cells and controls and assessed their respective mitotane sensitivities by MTT assay. We performed exome sequencing and electron microscopy, conducted gene expression microarray analysis and determined intracellular lipid concentrations in the presence and absence of mitotane. Clonal cell lines established after pulsed treatment were resistant to mitotane (IC50 of 102.2 ± 7.3 µM (n = 12) vs 39.4 ± 6.2 µM (n = 6) in controls (biological replicates, mean ± s.d., P = 0.0001)). Unlike nonresistant clones, resistant clones maintained normal mitochondrial and nucleolar morphology during mitotane treatment. Resistant clones largely shared structural and single nucleotide variants, suggesting a common cell of origin. Resistance depended, in part, on extracellular lipoproteins and was associated with alterations in intracellular lipid homeostasis, including levels of free cholesterol, as well as decreased steroid production. By gene expression analysis, resistant cells showed profound alterations in pathways including steroid metabolism and transport, apoptosis, cell growth and Wnt signaling. These studies establish an in vitro model of mitotane resistance in ACC and point to underlying molecular mechanisms. They may enable future studies to overcome resistance in vitro and improve ACC treatment in vivo.

Objectives: The ideal timing and technique of tracheostomy vary among patients and may impact outcomes. We aim to examine the association between tracheostomy timing, placement technique, and patient demographics on survival.Study Design: Retrospective cohort study. Methods: A retrospective review was performed for all patients who underwent tracheostomy in 2016 and 2017 at one urban academic tertiary-care hospital. Kaplan-Meier curves were created based on combinations of tracheostomy timing and technique (early percutaneous, early non-percutaneous, late percutaneous, and late non-percutaneous). Cox proportional hazard models were used to determine multivariable effects of timing, technique, and other demographic factors. Primary outcome measures were tracheostomy-related mortality and overall survival. Secondary outcomes were in-hospital, 30-day, and 90-day mortality.Results: Our study included 523 patients. There were six tracheostomy-related deaths, with hemorrhage and tracheoesophageal fistula being the most common causes. Tracheostomy timing and technique combinations were not associated with differences in all-cause mortality or survival following discharge. Cox proportional hazard models showed that Charlson Comorbidity Index (CCI) and unknown partner status were associated with a decrease in survival (P < .01 and P = .05, respectively). Additionally, patient age, gender, race, CCI, and body mass index were not independently associated with changes in survival.Conclusion: Late and non-percutaneous tracheostomies were associated with more tracheostomy-related deaths, but timing and technique were not associated with differences in patient survival. Multiple regression analysis showed that increased patient comorbidities, measured via CCI, and unknown partner status were independently associated with decreased survival. Proceduralists should discuss timing, technique, and patient social factors together with the medical care team when constructing plans for postdischarge management.

Objective This investigation aims to review the known genetic mutations associated with oral cavity squamous cell carcinoma (OCSCC) in young adults with limited environmental risk factors (YLERs). Data Sources A comprehensive search strategy was designed to identify studies in MEDLINE (Ovid), Embase (Ovid), and Scopus from database inception to May 2017 that included adults ≤50 years of age with OCSCC and minimal tobacco use history (≤10 pack-years) who had their tumors genetically sequenced or mutational profiles analyzed. Review Methods Identified articles were screened by 2 reviewers. Quality of evidence was graded by the MINORS criteria for case-control studies; other studies were graded by assigning a level of evidence for gene mutation literature. Results Thirteen studies met our inclusion criteria, and 130 patients met our criteria for age and tobacco history. TP53 was the most commonly evaluated gene (10 of 13 studies) and the most frequently observed mutation. One study reported that nonsmokers had significantly fewer TP53 mutations, while 9 studies found no difference in the prevalence of TP53 mutations. No other mutations were found specific to this cohort. Conclusions TP53 mutations may occur at a similar rate in YLERs with OCSCC as compared with older patients or those with risk factors. However, few studies have aimed to characterize the genetic landscape of oral cavity tumors in this population, often with small sample sizes. Future studies are needed to explore unidentified genetic alterations leading to tumor susceptibility or alternative mechanisms of carcinogenesis.