Yeast Platforms for Production and Screening of Bioactive Derivatives of Rauwolscine.

Monoterpene indole alkaloids (MIAs) make up a highly bioactive class of metabolites produced by a range of tropical and subtropical plants. The corynanthe-type MIAs are a stereochemically complex subclass with therapeutic potential against a large number of indications including cancer, psychotic disorders, and erectile dysfunction. Here, we report yeast-based cell factories capable of de novo production of corynanthe-type MIAs rauwolscine, yohimbine, tetrahydroalstonine, and corynanthine. From this, we demonstrate regioselective biosynthesis of 4 fluorinated derivatives of these compounds and de novo biosynthesis of 7-chlororauwolscine by coexpression of a halogenase with the biosynthetic pathway. Finally, we capitalize on the ability of these cell factories to produce derivatives of these bioactive scaffolds to establish a proof-of-principle drug discovery pipeline in which the corynanthe-type MIAs are screened for bioactivity on human drug targets, expressed in yeast. In doing so, we identify antagonistic and agonistic behavior against the human adrenergic G protein-coupled receptors ADRA2A and ADRA2B, and the serotonergic receptor 5HT4b, respectively. This study thus demonstrates a proto-drug discovery pipeline for bioactive plant-inspired small molecules based on one-pot biocatalysis of natural and new-to-nature corynanthe-type MIAs in yeast.

Surgical resection as a curative intervention for solitary renal cell carcinoma metastasis to the nasal cavity.

Persistent unilateral nasal obstruction with recurrent epistaxis in an adult should raise suspicion of malignancy. Renal cell carcinoma accounts for 90% of all renal malignancies but rarely manifests as a nasal mass. We describe a case of clear cell renal cell carcinoma metastasizing to the nasal cavity.

The Madagascar palm genome provides new insights on the evolution of Apocynaceae specialized metabolism.

Specialized metabolites possess diverse interesting biological activities and some cardenolides- and monoterpene indole alkaloids- (MIAs) derived pharmaceuticals are currently used to treat human diseases such as cancers or hypertension. While these two families of biocompounds are produced by specific subfamilies of Apocynaceae, one member of this medicinal plant family, the succulent tree Pachypodium lamerei Drake (also known as Madagascar palm), does not produce such specialized metabolites. To explore the evolutionary paths that have led to the emergence and loss of cardenolide and MIA biosynthesis in Apocynaceae, we sequenced and assembled the P. lamerei genome by combining Oxford Nanopore Technologies long-reads and Illumina short-reads. Phylogenomics revealed that, among the Apocynaceae whose genomes have been sequenced, the Madagascar palm is so far the species closest to the common ancestor between MIA producers/non-MIA producers. Transposable elements, constituting 72.48% of the genome, emerge as potential key players in shaping genomic architecture and influencing specialized metabolic pathways. The absence of crucial MIA biosynthetic genes such as strictosidine synthase in P. lamerei and non-Rauvolfioideae species hints at a transposon-mediated mechanism behind gene loss. Phylogenetic analysis not only showcases the evolutionary divergence of specialized metabolite biosynthesis within Apocynaceae but also underscores the role of transposable elements in this intricate process. Moreover, we shed light on the low conservation of enzymes involved in the final stages of MIA biosynthesis in the distinct MIA-producing plant families, inferring independent gains of these specialized enzymes along the evolution of these medicinal plant clades. Overall, this study marks a leap forward in understanding the genomic dynamics underpinning the evolution of specialized metabolites biosynthesis in the Apocynaceae family, with transposons emerging as potential architects of genomics restructuring and gene loss.

Operative Experience of Esophageal Surgery among General Surgery Residents in the United States: An Analysis of ACGME Operative Case Logs.

INTRODUCTION: Esophageal surgery is an essential component of general surgery training and encompasses several types of cases that are logged by general surgery residents. There is a scarcity of data on the quality and volume of esophageal surgery experience during surgical residency in the United States. We analyzed trends for 9 different esophageal procedure categories logged by residents in the United States, with the aim to identify areas for improvement in training. METHODS: We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from programs accredited by the ACGME over a fourteen-year period from 2009 to 2023. Data on mean esophageal cases reported by graduates, including mean in each procedure subcategory were retrieved. Cases were categorized as either surgeon chief or surgeon junior for each procedure category. Mann-Kendall trend test was used to obtain tau statistics and p-value for trends in mean operative surgical volume for the total number of cases in each operative category over the study period. Trends in surgeon chief and surgeon junior cases were also investigated for each operative category. RESULTS: The mean number of all esophageal procedures performed per resident during their training increased significantly from 10.5 in 2009 to 16 in 2022 (τ = 0.833, p < 0.001). This trend observed among all esophageal procedures during this 14-year study can be largely attributed to the steady increase in the number and proportion of laparoscopic esophageal antireflux procedures performed (τ = 0.950, p < 0.001). Additionally, esophagectomy procedures had a statistically significant, but modest, increase during the study period (τ = 0.505, p = 0.023), from a mean of 1 case during training in 2009 to a peak of 1.3 in 2020. Although the general trend of esophagus procedures increased during the study period, most categories (7 out of 9) either decreased or did not significantly change. Esophagogastrectomy volume decreased significantly by 30%, from 1 per resident during their training in 2009 to 0.7 in 2022 (τ = -0.510, p = 0.018), esophageal diverticulectomy procedures decreased by 50% from 0.2 to 0.1 (τ = -0.609, p = 0.009), and operations for esophageal stenosis decreased by 75% from 0.4 to 0.1 (τ = -0.734, p = 0.001). Mean number of esophageal bypasses (τ = -0.128, p = 0.584), repair of perforated esophageal disease (τ = -0.333, p = 0.156), and other major esophagus procedures (τ = 0.416, p = 0.063) did not significantly change. CONCLUSION: The operative volume of esophageal surgery that general surgery residents in the United States are exposed to has significantly risen over the past 14 years, largely driven by the increase in laparoscopic antireflux procedures. However, given the recent advances and the resultant heterogeneity in both esophageal surgery, the increase in resident operative volume is still inadequate to ensure the training of safe and adept esophageal surgeons, necessitating postresidency specialized training for trainees interested in esophageal surgery.

Trends in gastric surgery operative experience among general surgery residents in the United States: A nationwide retrospective analysis.

BACKGROUND: Gastric surgery is a crucial component of general surgery training. However, there is a paucity of high-quality data on operative volume and the diversity of surgical procedures that general surgery residents are exposed to. METHODS: We conducted a retrospective analysis of operative case logs of all general surgery residents graduating from the American College of Graduate Medical Education-accredited program from 2009 to 2022. Data on the mean number of gastric procedures, including the mean in each subcategory, were retrieved. A Mann-Kendall trend test was used to investigate trends in operative volume. RESULTS: Between 2009 and 2022, the mean overall logged gastric procedures rose significantly (τ = 0.722, P < .001) from 36.2 in 2009 to 49.2 in 2022 (35.9% increase). The most substantial growth was seen in laparoscopic gastric reduction for morbid obesity (mean 1.9 in 2017 to 19 in 2022; τ = 0.670, P = .009). A statistically significant increase was also seen in laparoscopic partial gastric resections, repair of gastric perforation, and "other major stomach procedures" (P < .05 for all comparisons). Open gastrostomy, open partial gastric resections, and open vagotomy all significantly decreased (P < .05 for all comparisons). There was no significant change in the volume of laparoscopic gastrectomy, total gastric resections, and non-laparoscopic gastric reductions for morbid obesity (P > .05 for all comparisons). CONCLUSION: There has been a substantial increase in the volume of gastric surgery during residency over the past 14 years, driven mainly by an increase in laparoscopic gastric reduction. However, there may still be a need for further gastric surgical training to ensure well-rounded general surgeons.

Colon and Rectal Surgery Fellowship Applicant and Matching Trends in the United States: An Analysis of National Resident Matching Program Data.

BACKGROUND: Colon and Rectal Surgery fellowships are training programs that aim to train surgeons in the management of small bowel, colon, rectal, and anal pathologies. OBJECTIVE: We investigated trends in Colon and Rectal Surgery fellowship match to help applicants anticipate future fellowship application cycles. DESIGN: This was a retrospective cohort study of applicants in the Colon and Rectal Surgery match from 2009 to 2023. Proportion of positions filled, match rates, and rank-order lists were collected. The impact of US-MD, non-US-MD, and DO status on match rate was assessed. We used the Mann Kendall trend test to obtain tau statistic and P-value for temporal trends over time, while associations between categorical variables were investigated by a chi-square test. RESULTS: Fellowship programs increased from 43 to 67, positions increased from 78 to 110, and number of applicants rose from 113 to 135. Nearly all positions were filled from 2009 to 2023 (range: 96.3%-100%). The overall match rate fluctuated between 67.3% and 80.7%. The match rate over the past 5 years was 72.0%. The match rate for US-MDs was 80.0%, while non-US-MDs had a 56.2% match rate. The percentage matching at each rank were first choice 28.0%, second choice 10.4%, third choice 6.9%, and fourth choice or lower 23.5%. CONCLUSION: Despite an increase in Colon and Rectal Surgery fellowship positions, the overall match rate has not changed significantly over the years, mainly as a result of increased applicants.

Tumor Regression upon Intratumoral and Subcutaneous Dosing of the STING Agonist ALG-031048 in Mouse Efficacy Models.

Stimulator of interferon genes (STING) agonists have shown potent anti-tumor efficacy in various mouse tumor models and have the potential to overcome resistance to immune checkpoint inhibitors (ICI) by linking the innate and acquired immune systems. First-generation STING agonists are administered intratumorally; however, a systemic delivery route would greatly expand the clinical use of STING agonists. Biochemical and cell-based experiments, as well as syngeneic mouse efficacy models, were used to demonstrate the anti-tumoral activity of ALG-031048, a novel STING agonist. In vitro, ALG-031048 is highly stable in plasma and liver microsomes and is resistant to degradation via phosphodiesterases. The high stability in biological matrices translated to good cellular potency in a HEK 293 STING R232 reporter assay, efficient activation and maturation of primary human dendritic cells and monocytes, as well as long-lasting, antigen-specific anti-tumor activity in up to 90% of animals in the CT26 mouse colon carcinoma model. Significant reductions in tumor growth were observed in two syngeneic mouse tumor models following subcutaneous administration. Combinations of ALG-031048 and ICIs further enhanced the in vivo anti-tumor activity. This initial demonstration of anti-tumor activity after systemic administration of ALG-031048 warrants further investigation, while the combination of systemically administered ALG-031048 with ICIs offers an attractive approach to overcome key limitations of ICIs in the clinic.

Temporal trends in mortality location in patients with anal cancer in the USA: an analysis of the National Center for Health Statistics mortality data.

OBJECTIVES: Investigate trends in where patients died of anal cancer in the USA. METHODS: Retrospective cohort study using the US National Center for Health Statistics Wide-Ranging ONline Data for Epidemiologic Research platform from 2003 to 2020; all patients with death certificates listing anal cancer as the underlying cause of death in the USA. Main outcome measure of location of patient death: inpatient facility, home, hospice, nursing home/long-term care facility and other. RESULTS: There were a total of 16 296 deaths with anal cancer as the underlying diagnosis during the study period. The crude rate increased from 0.191 per 100 000 deaths in 2003 to 0.453 per 100 000 deaths in 2020. Over the study period, 22.4% of patient deaths occurred in inpatient facilities, 44.9% at home, 12.2% at hospice facilities and 13.1% at nursing homes/long-term care facilities. The percentage of deaths occurring in hospice facilities increased from 1.0% to 13.3% during the study period. Deaths at home also increased from 42.7% in 2003 to 55.8% in 2020. Meanwhile, inpatient deaths decreased from 33.5% in 2003 to 14.4% in 2020. CONCLUSIONS: There has been a significant increase in the proportion of patients with anal cancer dying at home or hospice from 2003 to 2020.

Patient Factors Influencing Speech Outcomes in Velopharyngeal Function Following Initial Cleft Palate Repair: A Systematic Review and Meta-Analysis.

OBJECTIVE: Identification of patient factors influencing velopharyngeal function for speech following initial cleft palate repair. DESIGN: A literature search of relevant databases from inception until 2018 was performed using medical subject headings and keywords related to cleft palate, palatoplasty and speech assessment. Following three stage screening data extraction was performed. SETTING: Systematic review and meta-analysis of relevant literature. PATIENTS/PARTICIPANTS: Three hundred and eighty-three studies met the inclusion criteria, comprising data on 47 658 participants. INTERVENTIONS: Individuals undergoing initial palatoplasty. MAIN OUTCOME MEASURES: Studies including participants undergoing initial cleft palate repair where the frequency of secondary speech surgery and/or velopharyngeal function for speech was recorded. RESULTS: Patient factors reported included cleft phenotype (95% studies), biological sex (64%), syndrome diagnosis (44%), hearing loss (28%), developmental delay (16%), Robin Sequence (16%) and 22q11.2 microdeletion syndrome (11%). Meta-analysis provided strong evidence that rates of secondary surgery and velopharyngeal dysfunction varied according to cleft phenotype (Veau I best outcomes, Veau IV worst outcomes), Robin Sequence and syndrome diagnosis. There was no evidence that biological sex was associated with worse outcomes. Many studies were poor quality with minimal follow-up. CONCLUSIONS: Meta-analysis demonstrated the association of certain patient factors with speech outcome, however the quality of the evidence was low. Uniform, prospective, multi-centre documentation of preoperative characteristics and speech outcomes is required to characterise risk factors for post-palatoplasty velopharyngeal insufficiency for speech. SYSTEMATIC REVIEW REGISTRATION: Registered with PROSPERO CRD42017051624.

Discriminatory Ability of Gas Chromatography-Ion Mobility Spectrometry to Identify Patients Hospitalized With COVID-19 and Predict Prognosis.

Background: Rapid diagnostic and prognostic tests for coronavirus disease (COVID-19) are urgently required. We aimed to evaluate the diagnostic and prognostic ability of breath analysis using gas chromatography-ion mobility spectrometry (GC-IMS) in hospitalized patients with COVID-19. Methods: Between February and May 2021, we took 1 breath sample for analysis using GC-IMS from participants who were admitted to the hospital for COVID-19, participants who were admitted to the hospital for other respiratory infections, and symptom-free controls, at the University Hospitals of Leicester NHS Trust, United Kingdom. Demographic, clinical, and radiological data, including requirement for continuous positive airway pressure (CPAP) ventilation as a marker for severe disease in the COVID-19 group, were collected. Results: A total of 113 participants were recruited into the study. Seventy-two (64%) were diagnosed with COVID-19, 20 (18%) were diagnosed with another respiratory infection, and 21 (19%) were healthy controls. Differentiation between participants with COVID-19 and those with other respiratory tract infections with GC-IMS was highly accurate (sensitivity/specificity, 0.80/0.88; area under the receiver operating characteristics curve [AUROC], 0.85; 95% CI, 0.74-0.96). GC-IMS was also moderately accurate at identifying those who subsequently required CPAP (sensitivity/specificity, 0.62/0.80; AUROC, 0.70; 95% CI, 0.53-0.87). Conclusions: GC-IMS shows promise as both a diagnostic tool and a predictor of prognosis in hospitalized patients with COVID-19 and should be assessed further in larger studies.

Screw-only fibular construct for Weber B ankle fractures: A retrospective clinical and cost comparison to assess feasibility for resource-limited settings.

INTRODUCTION: Ankle fractures are one of the most common injuries sustained worldwide, with the majority being isolated lateral malleolus fractures. The majority of the world's population live in Low and Middle Income Countries (LMIC), where implant cost may limit surgical treatment of ankle fractures. We investigate if Weber B ankle fractures could be effectively treated with a lower-cost technique using two screws between the fibula and the tibia to neutralize an interfragmentary lag screw. METHODS: After IRB approval, consecutive patients from January 1, 2020 to December 31, 2020 with Weber-B ankle fractures were treated using AO technique (AOT) with plate osteosynthesis neutralizing an interfragmentary screw. Syndesmotic injuries, as well as injuries to the medial malleolus or foot were treated according to the surgeon's preferences. From January 1, 2021 to December 31, 2021 these injuries were treated with a screw-only technique (SOT) with two fibula pro tibia screws to neutralize an interfragmentary screw. Patient demographics including age, sex, BMI, smoking status, associated rheumatoid arthritis, and associated diabetes mellitus were recorded. The primary outcome variable was a stable radiographic mortise at six weeks post-surgery, secondary outcome variables included clinical union, infection, hardware removal, and implant cost for lateral malleolar fixation charged to the hospital. RESULTS: Seventeen AOT and 10 SOT constructs were included. Demographic characteristics were similar between groups. All fractures maintained a stable mortise with clinical union at 6 weeks without infection. There was a statistically significant difference in hardware removal (17.6% AOT, 50% SOT, p = 0.012). The average implant cost to the hospital of the lateral malleolar fixation was significantly less in the SOT group ($592 (SD $229)), compared to the AOT group ($1,949.97 (SD $562)), (p < 0.0001). CONCLUSION: We introduce proof of concept of a novel lower-cost fixation strategy for Weber B ankle fractures that maintained a stable mortise with clinical union at six weeks post-surgery. However, there was a significantly higher rate of hardware removal following fixation with a screw-only construct.

Diagnostic accuracy of computed tomography in differentiating peritoneal tuberculosis from peritoneal carcinomatosis.

INTRODUCTION: Peritoneal tuberculosis is difficult to diagnose as it may mimic peritoneal carcinomatosis, which has similar symptomatology. We sought to determine the diagnostic accuracy of computed tomography in differentiating peritoneal tuberculosis versus peritoneal carcinomatosis. MATERIALS AND METHODS: The associations of radiological findings in 124 patients with peritoneal carcinomatosis (n = 55) or tuberculosis (n = 69) were determined using Chi-square test. Sensitivity, specificity, positive and negative predictive value, and total diagnostic accuracy of CT imaging, with histopathology as gold standard, was determined. Subgroup analyses to determine these parameters by age (>40 years and ≤40 years) and gender (male and female) were performed. RESULTS: Mean age of study population was 44.1 ± 13.2 years with 61 males (49.2%) and 63 females (50.8%). The most common radiological abnormality in both peritoneal carcinomatosis (90.9%) and peritoneal tuberculosis (89.9%) was omental smudging, followed by presence of extraperitoneal mass (81.8%) in carcinomatosis and presence of micro-nodules in tuberculosis (88.4%). The findings significantly different in both the carcinomatosis and tuberculosis groups were high-density ascites, splenic calcification, splenomegaly, lymph node calcifications, micro-nodules, and macro-nodules. The diagnostic accuracy of CT in differentiating peritoneal tuberculosis from peritoneal carcinomatosis was 83.8%; sensitivity and specificity for peritoneal tuberculosis were 88.4% and 78.2%, respectively. CONCLUSION: The diagnostic accuracy of CT in differentiating peritoneal tuberculosis from peritoneal carcinomatosis revealed an overall diagnostic accuracy of 83.8%. Subgroup analysis revealed that CT may be a more specific diagnostic tool to predict peritoneal tuberculosis in female patients and in those over 40 years old.

An updated version of the Madagascar periwinkle genome.

The Madagascar periwinkle, Catharanthus roseus, belongs to the Apocynaceae family. This medicinal plant, endemic to Madagascar, produces many important drugs including the monoterpene indole alkaloids (MIA) vincristine and vinblastine used to treat cancer worldwide. Here, we provide a new version of the C. roseus genome sequence obtained through the combination of Oxford Nanopore Technologies long-reads and Illumina short-reads. This more contiguous assembly consists of 173 scaffolds with a total length of 581.128 Mb and an N50 of 12.241 Mb. Using publicly available RNAseq data, 21,061 protein coding genes were predicted and functionally annotated. A total of 42.87% of the genome was annotated as transposable elements, most of them being long-terminal repeats. Together with the increasing access to MIA-producing plant genomes, this updated version should ease evolutionary studies leading to a better understanding of MIA biosynthetic pathway evolution.

Synthesis and antiviral activity of fatty acyl conjugates of remdesivir against severe acute respiratory syndrome coronavirus 2 and Ebola virus.

We report here the synthesis, purification, and characterization of mono- and di-fatty acyl conjugates of remdesivir (RDV) and their in vitro antiviral activity against SAR-CoV-2, an Ebola virus transcription- and replication-competent virus-like particle (trVLP) system, and infectious Ebola virus. The most potent monofatty acyl conjugate was 4b, containing a 4-oxatetradecanolyl at the 3' position. Monofatty acyl conjugates, 3'-O-tetradecanoyl (4a) (IC50(VeroE6) = 2.3 µM; IC50(Calu3) = 0.24 µM), 3'-O-4-oxatetradodecanoyl (4b) (IC50(VeroE6) = 2.0 µM; IC50(Calu3) = 0.18 µM), and 3'-O-(12-ethylthiododecanoyl) (4e) (IC50(VeroE6) = 2.4 µM; IC50(Calu3) = 0.25 µM) derivatives exhibited less activity than RDV (IC50(VeroE6) = 0.85 µM; IC50(Calu3) = 0.06 µM) in both VeroE6 and Calu3 cells. Difatty acylation led to a significant reduction in the antiviral activity of RDV (as shown in conjugates 5a and 5b) against SARS-CoV-2 when compared with monofatty acylation (3a-e and 4a-e). About 77.9% of 4c remained intact after 4 h incubation with human plasma while only 47% of parent RDV was observed at the 2 h time point. The results clearly indicate the effectiveness of fatty acylation to improve the half-life of RDV. The antiviral activities of a number of monofatty acyl conjugates of RDV, such as 3b, 3e, and 4b, were comparable with RDV against the Ebola trVLP system. Meanwhile, the corresponding physical mixtures of RDV and fatty acids 6a and 6b showed 1.6 to 2.2 times less antiviral activity than the corresponding conjugates, 4a and 4c, respectively, against SARS-CoV-2 in VeroE6 cells. A significant reduction in viral RNA synthesis was observed for selected compounds 3a and 4b consistent with the IC50 results. These studies indicate the potential of these compounds as long-acting antiviral agents or prodrugs of RDV.

Marburg and Ebola Virus mRNA 3' Untranslated Regions Contain Negative Regulators of Translation That Are Modulated by ADAR1 Editing.

The filovirus family includes deadly pathogens such as Ebola virus (EBOV) and Marburg virus (MARV). A substantial portion of filovirus genomes encode 5' and 3' untranslated regions (UTRs) of viral mRNAs. Select viral genomic RNA sequences corresponding to 3' UTRs are prone to editing by adenosine deaminase acting on RNA 1 (ADAR1). A reporter mRNA approach, in which different 5' or 3' UTRs were inserted into luciferase-encoding mRNAs, demonstrates that MARV 3' UTRs yield different levels of reporter gene expression, suggesting modulation of translation. The modulation occurs in cells unable to produce microRNAs (miRNAs) and can be recapitulated in a MARV minigenome assay. Deletion mutants identified negative regulatory regions at the ends of the MARV nucleoprotein (NP) and large protein (L) 3' UTRs. Apparent ADAR1 editing mutants were previously identified within the MARV NP 3' UTR. Introduction of these changes into the MARV nucleoprotein (NP) 3' UTR or deletion of the region targeted for editing enhances translation, as indicated by reporter assays and polysome analysis. In addition, the parental NP 3' UTR, but not the edited or deletion mutant NP 3' UTRs, induces a type I interferon (IFN) response upon transfection into cells. Because some EBOV isolates from the West Africa outbreak exhibited ADAR1 editing of the viral protein of 40 kDa (VP40) 3' UTR, VP40 3' UTRs with parental and edited sequences were similarly assayed. The EBOV VP40 3' UTR edits also enhanced translation, but neither the wild-type nor the edited 3' UTRs induced IFN. These findings implicate filoviral mRNA 3' UTRs as negative regulators of translation that can be inactivated by innate immune responses that induce ADAR1. IMPORTANCE UTRs comprise a large percentage of filovirus genomes and are apparent targets of editing by ADAR1, an enzyme with pro- and antiviral activities. However, the functional significance of the UTRs and ADAR1 editing has been uncertain. This study demonstrates that MARV and EBOV 3' UTRs can modulate translation, in some cases negatively. ADAR1 editing or deletion of select regions within the translation suppressing 3' UTRs relieves the negative effects of the UTRs. These data indicate that filovirus 3' UTRs contain translation regulatory elements that are modulated by activation of ADAR1, suggesting a complex interplay between filovirus gene expression and innate immunity.

Mechanisms of anti-vesicular stomatitis virus activity of deazaneplanocin and its 3-brominated analogs.

3-deazaneplanocin A (DzNep) and its 3-brominated analogs inhibit replication of several RNA viruses. This antiviral activity is attributed to inhibition of S-adenosyl homocysteine hydrolase (SAHase) and consequently inhibition of viral methyltransferases, impairing translation of viral transcripts. The L-enantiomers of some derivatives retain antiviral activity despite dramatically reduced inhibition of SAHase in vitro. To better understand the mechanisms by which these compounds exert their antiviral effects, we compared DzNep, its 3-bromo-derivative, CL123, and the related enantiomers, CL4033 and CL4053, for their activities towards the model negative-sense RNA virus vesicular stomatitis virus (VSV). In cell culture, DzNep, CL123 and CL4033 each exhibited 50 percent inhibitory concentrations (IC50s) in the nanomolar range whereas the IC50 for the L-form, CL4053, was 34-85 times higher. When a CL123-resistant mutant (VSVR) was selected, it exhibited cross-resistance to each of the neplanocin analogs, but retained sensitivity to the adenosine analog BCX4430, an RNA chain terminator. Sequencing of VSVR identified a mutation in the C-terminal domain (CTD) of the viral large (L) protein, a domain implicated in regulation of L protein methyltransferase activity. CL123 inhibited VSV viral mRNA 5' cap methylation, impaired viral protein synthesis and decreased association of viral mRNAs with polysomes. Modest impacts on viral transcription were also demonstrated. VSVR exhibited partial resistance in each of these assays but its replication was impaired, relative to the parent VSV, in the absence of the inhibitors. These data suggest that DzNep, CL123 and CL4033 inhibit VSV through impairment of viral mRNA cap methylation and that the L-form, CL4053, based on the cross-resistance of VSVR, may act by a similar mechanism.

Pulsed Broad-Spectrum UV Light Effectively Inactivates SARS-CoV-2 on Multiple Surfaces and N95 Material.

The ongoing SARS-CoV-2 pandemic has resulted in an increased need for technologies capable of efficiently disinfecting public spaces as well as personal protective equipment. UV light disinfection is a well-established method for inactivating respiratory viruses. Here, we have determined that broad-spectrum, pulsed UV light is effective at inactivating SARS-CoV-2 on multiple surfaces in vitro. For hard, non-porous surfaces, we observed that SARS-CoV-2 was inactivated to undetectable levels on plastic and glass with a UV dose of 34.9 mJ/cm2 and stainless steel with a dose of 52.5 mJ/cm2. We also observed that broad-spectrum, pulsed UV light is effective at reducing SARS-CoV-2 on N95 respirator material to undetectable levels with a dose of 103 mJ/cm2. We included UV dosimeter cards that provide a colorimetric readout of UV dose and demonstrated their utility as a means to confirm desired levels of exposure were reached. Together, the results presented here demonstrate that broad-spectrum, pulsed UV light is an effective technology for the in vitro inactivation of SARS-CoV-2 on multiple surfaces.

Contamination of the Mini C-Arm During Foot and Ankle Surgery.

BACKGROUND: Many orthopedic surgeries utilize intraoperative fluoroscopy. The mini C-arm is an advantageous device as it can be easily used without the need for a dedicated radiology technician. However, there are concerns that the mini C-arm may represent a potential source of contamination and subsequent postoperative infection. Previous investigations of standard C-arm drapes have shown high rates of contamination. Similar contamination rates would be even more concerning for the mini C-arm as it requires physically maneuvering the machine. This study aimed to determine the rate of mini C-arm drape contamination and identify high-risk areas. METHODS: Fifty foot and ankle surgeries requiring the use of mini C-arm fluoroscopy were included. Eight locations on the mini C-arm drape were sampled at the conclusion of each procedure. Culture Q-swabs were used for sampling defined locations. Swab samples were then assessed for bacterial growth on a 5% blood agar plate using a semiquantitative technique. RESULTS: In 70% of surgical cases, contamination was observed in at least 1 location. Six of the 8 evaluated locations were found to have significantly higher contamination in comparison with their corresponding negative controls (Mann-Whitney U test, P < .05). The "outer portion of the upper arm" (location 1) exhibited bacteria growth in 26% (P < .0001) of cases. The "superior portion of the x-ray source" (location 2) exhibited growth in 30% (P < .0001) of cases. These were the highest-risk areas for contamination and were both significantly more likely to be involved than the "inferior portion of the x-ray source" and "superior portion of the beam receiver," locations 4 and 5, respectively. Fourteen percent (7/50) C-arm cases and 1.72% (1/58) Achilles tendon surgery control cases developed surgical site infection (P = .0234; OR, 9.27). CONCLUSION: Bacterial contamination of the mini C-arm drape was found to be common after foot and ankle procedures. Contamination was more prevalent on the outer ring areas of the C-arm, both at the emitter and receiver. LEVEL OF EVIDENCE: Level III, prospective cohort study.

Effects of Appended Poly(ethylene glycol) on Electrochemical CO2 Reduction by an Iron Porphyrin Complex.

Electrochemical carbon dioxide (CO2) reduction is a sustainable approach for transforming atmospheric CO2 into chemical feedstocks and fuels. To overcome the kinetic barriers of electrocatalytic CO2 reduction, catalysts with high selectivity, activity, and stability are needed. Here, we report an iron porphyrin complex, FePEGP, with a poly(ethylene glycol) unit in the second coordination sphere, as a highly selective and active electrocatalyst for the electrochemical reduction of CO2 to carbon monoxide (CO). Controlled-potential electrolysis using FePEGP showed a Faradaic efficiency of 98% and a current density of -7.8 mA/cm2 at -2.2 V versus Fc/Fc+ in acetonitrile using water as the proton source. The maximum turnover frequency was calculated to be 1.4 × 105 s-1 using foot-of-the-wave analysis. Distinct from most other catalysts, the kinetic isotope effect (KIE) study revealed that the protonation step of the Fe-CO2 adduct is not involved in the rate-limiting step. This model shows that the PEG unit as the secondary coordination sphere enhances the catalytic kinetics and thus is an effective design for electrocatalytic CO2 reduction.

Regulation of gene transcription by thyroid hormone receptor ß agonists in clinical development for the treatment of non-alcoholic steatohepatitis (NASH).

Thyroid hormones are important modulators of metabolic activity in mammals and alter cholesterol and fatty acid levels through activation of the nuclear thyroid hormone receptor (THR). Currently, there are several THRß agonists in clinical trials for the treatment of non-alcoholic steatohepatitis (NASH) that have demonstrated the potential to reduce liver fat and restore liver function. In this study, we tested three THRß-agonism-based NASH treatment candidates, GC-1 (sobetirome), MGL-3196 (resmetirom), and VK2809, and compared their selectivity for THRß and their ability to modulate the expression of genes specific to cholesterol and fatty acid biosynthesis and metabolism in vitro using human hepatic cells and in vivo using a rat model. Treatment with GC-1 upregulated the transcription of CPT1A in the human hepatocyte-derived Huh-7 cell line with a dose-response comparable to that of the native THR ligand, triiodothyronine (T3). VK2809A (active parent of VK2809), MGL-3196, and VK2809 were approximately 30-fold, 1,000-fold, and 2,000-fold less potent than T3, respectively. Additionally, these relative potencies were confirmed by quantification of other direct gene targets of THR, namely, ANGPTL4 and DIO1. In primary human hepatocytes, potencies were conserved for every compound except for VK2809, which showed significantly increased potency that was comparable to that of its active counterpart, VK2809A. In high-fat diet fed rats, a single dose of T3 significantly reduced total cholesterol levels and concurrently increased liver Dio1 and Me1 RNA expression. MGL-3196 treatment resulted in concentration-dependent decreases in total and low-density lipoprotein cholesterol with corresponding increases in liver gene expression, but the compound was significantly less potent than T3. In conclusion, we have implemented a strategy to rank the efficacy of THRß agonists by quantifying changes in the transcription of genes that lead to metabolic alterations, an effect that is directly downstream of THR binding and activation.