Seasonal human coronavirus antibodies are boosted upon SARS-CoV-2 infection but not associated with protection.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread within the human population. Although SARS-CoV-2 is a novel coronavirus, most humans had been previously exposed to other antigenically distinct common seasonal human coronaviruses (hCoVs) before the coronavirus disease 2019 (COVID-19) pandemic. Here, we quantified levels of SARS-CoV-2-reactive antibodies and hCoV-reactive antibodies in serum samples collected from 431 humans before the COVID-19 pandemic. We then quantified pre-pandemic antibody levels in serum from a separate cohort of 251 individuals who became PCR-confirmed infected with SARS-CoV-2. Finally, we longitudinally measured hCoV and SARS-CoV-2 antibodies in the serum of hospitalized COVID-19 patients. Our studies indicate that most individuals possessed hCoV-reactive antibodies before the COVID-19 pandemic. We determined that ∼20% of these individuals possessed non-neutralizing antibodies that cross-reacted with SARS-CoV-2 spike and nucleocapsid proteins. These antibodies were not associated with protection against SARS-CoV-2 infections or hospitalizations, but they were boosted upon SARS-CoV-2 infection.

FDA-approved disulfiram inhibits pyroptosis by blocking gasdermin D pore formation.

Cytosolic sensing of pathogens and damage by myeloid and barrier epithelial cells assembles large complexes called inflammasomes, which activate inflammatory caspases to process cytokines (IL-1ß) and gasdermin D (GSDMD). Cleaved GSDMD forms membrane pores, leading to cytokine release and inflammatory cell death (pyroptosis). Inhibiting GSDMD is an attractive strategy to curb inflammation. Here we identify disulfiram, a drug for treating alcohol addiction, as an inhibitor of pore formation by GSDMD but not other members of the GSDM family. Disulfiram blocks pyroptosis and cytokine release in cells and lipopolysaccharide-induced septic death in mice. At nanomolar concentration, disulfiram covalently modifies human/mouse Cys191/Cys192 in GSDMD to block pore formation. Disulfiram still allows IL-1ß and GSDMD processing, but abrogates pore formation, thereby preventing IL-1ß release and pyroptosis. The role of disulfiram in inhibiting GSDMD provides new therapeutic indications for repurposing this safe drug to counteract inflammation, which contributes to many human diseases.

Non-epitaxial single-crystal 2D material growth by geometric confinement.

Two-dimensional (2D) materials and their heterostructures show a promising path for next-generation electronics1-3. Nevertheless, 2D-based electronics have not been commercialized, owing mainly to three critical challenges: i) precise kinetic control of layer-by-layer 2D material growth, ii) maintaining a single domain during the growth, and iii) wafer-scale controllability of layer numbers and crystallinity. Here we introduce a deterministic, confined-growth technique that can tackle these three issues simultaneously, thus obtaining wafer-scale single-domain 2D monolayer arrays and their heterostructures on arbitrary substrates. We geometrically confine the growth of the first set of nuclei by defining a selective growth area via patterning SiO2 masks on two-inch substrates. Owing to substantial reduction of the growth duration at the micrometre-scale SiO2 trenches, we obtain wafer-scale single-domain monolayer WSe2 arrays on the arbitrary substrates by filling the trenches via short growth of the first set of nuclei, before the second set of nuclei is introduced, thus without requiring epitaxial seeding. Further growth of transition metal dichalcogenides with the same principle yields the formation of single-domain MoS2/WSe2 heterostructures. Our achievement will lay a strong foundation for 2D materials to fit into industrial settings.

Vertical full-colour micro-LEDs via 2D materials-based layer transfer.

Micro-LEDs (µLEDs) have been explored for augmented and virtual reality display applications that require extremely high pixels per inch and luminance1,2. However, conventional manufacturing processes based on the lateral assembly of red, green and blue (RGB) µLEDs have limitations in enhancing pixel density3-6. Recent demonstrations of vertical µLED displays have attempted to address this issue by stacking freestanding RGB LED membranes and fabricating top-down7-14, but minimization of the lateral dimensions of stacked µLEDs has been difficult. Here we report full-colour, vertically stacked µLEDs that achieve, to our knowledge, the highest array density (5,100 pixels per inch) and the smallest size (4 µm) reported to date. This is enabled by a two-dimensional materials-based layer transfer technique15-18 that allows the growth of RGB LEDs of near-submicron thickness on two-dimensional material-coated substrates via remote or van der Waals epitaxy, mechanical release and stacking of LEDs, followed by top-down fabrication. The smallest-ever stack height of around 9 µm is the key enabler for record high µLED array density. We also demonstrate vertical integration of blue µLEDs with silicon membrane transistors for active matrix operation. These results establish routes to creating full-colour µLED displays for augmented and virtual reality, while also offering a generalizable platform for broader classes of three-dimensional integrated devices.

A Constitutive EGFR Kinase Dimer to Study Inhibitor Pharmacology.

Lung cancer is commonly caused by activating mutations in the epidermal growth factor receptor (EGFR). Allosteric kinase inhibitors are unaffected by common ATP-site resistance mutations and represent a promising therapeutic strategy for targeting drug-resistant EGFR variants. However, allosteric inhibitors are antagonized by kinase dimerization, and understanding this phenomenon has been limited to cellular experiments. To facilitate the study of allosteric inhibitor pharmacology, we designed and purified a constitutive EGFR kinase dimer harboring the clinically relevant L858R/T790M mutations. Kinetic characterization revealed that the EGFR kinase dimer is more active than monomeric EGFR(L858R/T790M) kinase and has the same Km,ATP Biochemical profiling of a large panel of ATP-competitive and allosteric EGFR inhibitors showed that allosteric inhibitor potency decreased by >500-fold in the kinase dimer compared with monomer, yielding IC50 values that correlate well with Ba/F3 cellular potencies. Thus, this readily purifiable constitutive asymmetric EGFR kinase dimer represents an attractive tool for biochemical evaluation of EGFR inhibitor pharmacology, in particular for allosteric inhibitors. SIGNIFICANCE STATEMENT: Drugs targeting epidermal growth factor receptor (EGFR) kinase are commonly used to treat lung cancers but are affected by receptor dimerization. Here, we describe a locked kinase dimer that can be used to study EGFR inhibitor pharmacology.

Role of omega-3 endocannabinoids in the modulation of T-cell activity in a multiple sclerosis experimental autoimmune encephalomyelitis (EAE) model.

Epidemiological studies show that omega-3 fatty acid consumption is associated with improved conditions in neurodegenerative diseases such as multiple sclerosis (MS). However, the mechanism of this association is not well understood. Emerging evidence suggests that parent molecules such as docosahexaenoic acid are converted into downstream metabolites that are capable of directly modulating immune responses. In vitro, we found that docosahexaenoyl ethanolamide (DHEA), another dietary component and its epoxide metabolite, reduced the polarization of naïve T-cells toward proinflammatory Th1 and Th17 phenotypes. Furthermore, we identified that DHEA and related endocannabinoids are changing during the disease progression in mice undergoing relapse-remitting experimental autoimmune encephalomyelitis (RR-EAE). In addition, daily administration of DHEA to mice delayed the onset of disease, the rate of relapse, and the severity of clinical scores at relapse in RR-EAE, an animal model of MS. Collectively, these data indicate that DHEA and their downstream metabolites reduce the disease severity in the RR-EAE model of MS and can be potential dietary adjuvants to existing MS therapeutics.

Unfermented ß-fructan Fibers Fuel Inflammation in Select Inflammatory Bowel Disease Patients.

BACKGROUND & AIMS: Inflammatory bowel diseases (IBD) are affected by dietary factors, including nondigestible carbohydrates (fibers), which are fermented by colonic microbes. Fibers are overall beneficial, but not all fibers are alike, and some patients with IBD report intolerance to fiber consumption. Given reproducible evidence of reduced fiber-fermenting microbes in patients with IBD, we hypothesized that fibers remain intact in select patients with reduced fiber-fermenting microbes and can then bind host cell receptors, subsequently promoting gut inflammation. METHODS: Colonic biopsies cultured ex vivo and cell lines in vitro were incubated with oligofructose (5 g/L), or fermentation supernatants (24-hour anaerobic fermentation) and immune responses (cytokine secretion [enzyme-linked immunosorbent assay/meso scale discovery] and expression [quantitative polymerase chain reaction]) were assessed. Influence of microbiota in mediating host response was examined and taxonomic classification of microbiota was conducted with Kraken2 and metabolic profiling by HUMAnN2, using R software. RESULTS: Unfermented dietary ß-fructan fibers induced proinflammatory cytokines in a subset of IBD intestinal biopsies cultured ex vivo, and immune cells (including peripheral blood mononuclear cells). Results were validated in an adult IBD randomized controlled trial examining ß-fructan supplementation. The proinflammatory response to intact ß-fructan required activation of the NLRP3 and TLR2 pathways. Fermentation of ß-fructans by human gut whole microbiota cultures reduced the proinflammatory response, but only when microbes were collected from patients without IBD or patients with inactive IBD. Fiber-induced immune responses correlated with microbe functions, luminal metabolites, and dietary fiber avoidance. CONCLUSION: Although fibers are typically beneficial in individuals with normal microbial fermentative potential, some dietary fibers have detrimental effects in select patients with active IBD who lack fermentative microbe activities. The study is publicly accessible at the U.S. National Institutes of Health database (clinicaltrials.gov identification number NCT02865707).

Characterization and staging of outer plexiform layer development in human retina and retinal organoids.

The development of the first synapse of the visual system between photoreceptors and bipolar cells in the outer plexiform layer (OPL) of the human retina is crucial for visual processing but poorly understood. By studying the maturation state and spatial organization of photoreceptors, depolarizing bipolar cells and horizontal cells in the human fetal retina, we establish a pseudo-temporal staging system for OPL development that we term OPL-Stages 0 to 4. This was validated through quantification of increasingly precise subcellular localization of bassoon to the OPL with each stage (P<0.0001). By applying these OPL staging criteria to human retinal organoids (HROs) derived from human embryonic and induced pluripotent stem cells, we observed comparable maturation from OPL-Stage 0 at day 100 in culture up to OPL-Stage 3 by day 160. Quantification of presynaptic protein localization confirmed progression from OPL-Stage 0 to 3 (P<0.0001). Overall, this study defines stages of human OPL development through mid-gestation and establishes HROs as a model system that recapitulates key aspects of human photoreceptor-bipolar cell synaptogenesis in vitro.

Monolithic 3D integration of 2D materials-based electronics towards ultimate edge computing solutions.

Three-dimensional (3D) hetero-integration technology is poised to revolutionize the field of electronics by stacking functional layers vertically, thereby creating novel 3D circuity architectures with high integration density and unparalleled multifunctionality. However, the conventional 3D integration technique involves complex wafer processing and intricate interlayer wiring. Here we demonstrate monolithic 3D integration of two-dimensional, material-based artificial intelligence (AI)-processing hardware with ultimate integrability and multifunctionality. A total of six layers of transistor and memristor arrays were vertically integrated into a 3D nanosystem to perform AI tasks, by peeling and stacking of AI processing layers made from bottom-up synthesized two-dimensional materials. This fully monolithic-3D-integrated AI system substantially reduces processing time, voltage drops, latency and footprint due to its densely packed AI processing layers with dense interlayer connectivity. The successful demonstration of this monolithic-3D-integrated AI system will not only provide a material-level solution for hetero-integration of electronics, but also pave the way for unprecedented multifunctional computing hardware with ultimate parallelism.

Real time changes in the expression of eicosanoid synthesizing enzymes during inflammation.

Immune responses during inflammation involve complex, well-coordinated lipid signaling pathways. Eicosanoids are a class of lipid signaling molecules derived from polyunsaturated fatty acids such as arachidonic acid and constitute a major network that controls inflammation and its subsequent resolution. Arachidonic acid is metabolized by enzymes in three different pathways to form a variety of lipid metabolites that can be either pro- or anti-inflammatory. Therefore, an understanding of the time-dependent gene expression, lipid metabolite profiles and cytokine profiles during the initial inflammatory response is necessary, as it will allow for the design of time-dependent therapeutics. Herein, we investigate the multi-level regulation of this process. After stimulating RAW 264.7 cells, a mouse-derived macrophage cell line commonly used to examine inflammatory responses, we examine the gene expression of 44 relevant lipid metabolizing enzymes from the different eicosanoid synthesizing classes. We also measure the formation of lipid metabolites and production of cytokines at selected time points. Results reveal a dynamic relationship between the time-course of inflammation dependent gene expression of the three eicosanoid synthesizing enzymes.

Four intestinal ultrasound scores and bowel wall thickness alone correlated well with pediatric ulcerative colitis disease activity.

OBJECTIVES: Intestinal ultrasound (IUS) is a noninvasive tool in ulcerative colitis (UC), but scoring systems have mostly been developed for adults, Crohn's disease, and flaring UC. Our aim was to evaluate the performance of bowel wall thickness (BWT) and four IUS scores in pediatric patients with newly diagnosed UC. METHODS: Patients <18 years old with suspected UC were prospectively enrolled. Baseline IUS was done, and ulcerative colitis intestinal ultrasound score (UC-IUS), Milan criteria, simple pediatric activity ultrasound score (SPAUSS), and Civatelli Index were calculated. Mayo endoscopic segment subscore, pediatric ulcerative colitis activity index (PUCAI), and biomarkers were correlated with IUS using nonparametric and receiver operating characteristic analyses. RESULTS: Fifty-two patients (56% male, median age 13.9 years, interquartile range [IQR] 11.2-16.3) with 206 colon segments were included. Patients who needed hospitalization (n = 27/52) had significantly worse IUS (BWT and all scores) compared to those not hospitalized. For all patients, IUS scores and BWT significantly correlated with baseline endoscopic, clinical, and biochemical disease activity (p = 0.32-0.67, p < 0.05). BWT (τb = 0.53), UC-IUS (τb = 0.55), and Milan (τb = 0.52) had the strongest endoscopic correlations. For differentiating between endoscopic disease severity, BWT, UC-IUS, and Milan, had the highest areas under the curve (0.89-0.93). Using BWT alone, a thinner cut-off had improved sensitivity while maintaining high specificity: ≥2.5 mm for moderate/severe endoscopic inflammation (sensitivity 66%; specificity 94%) and ≥3.5 mm for severe endoscopic inflammation (sensitivity 92%; specificity 86%). CONCLUSIONS: BWT and all four IUS scores correlated well with endoscopic, clinical, and biochemical disease activity, and was another useful marker of severity in identifying patients needing hospitalization. Pediatric patients needed a thinner BWT cut-off, which should be accounted for when developing pediatric-specific scores. BWT alone may be just as clinically useful as composite US scores.

Midline Catheters as an Alternative for Central Venous Catheters in Venous Oxygen Saturation Monitoring: A Single Center Experience.

BACKGROUND: Central venous oxygen saturation (ScvO2) obtained from a central venous catheter (CVC) is often used to approximate oxygen delivery in critically ill patients. Despite their importance in administering medications and monitoring oxygen delivery, the use of CVCs can be associated with significant complications. Midline catheters are inserted via a peripheral vein above the antecubital fossa and provide a safe alternative to CVCs. This study aimed to determine the equivalence of ScvO2 and midline catheter oxygen saturation (SmO2) in critically ill patients. METHODS: This was a single-center observational study of critically ill adult patients who had concurrently placed CVCs (internal jugular and subclavian) and midline catheters as part of standard ICU care. Venous oxygen saturation and lactate levels were measured from both catheters using the Abbott point-of-care i-STAT analyzer. Demographic and ICU admission data were collected. Continuous variables were compared using the paired t-test. Pearson's correlation was used to evaluate the linear correlation between ScvO2 and SmO2. The systematic error (bias) was calculated using Bland-Altman analysis. Receiver operating characteristic curves were constructed to evaluate the sensitivities and specificities for different values of SmO2 to predict ScvO2. RESULTS: Forty-eight patients (n = 48) were enrolled in the study. The mean ScvO2 and SmO2 were 65.5% +/- 11.2% and 62.7% +/- 17.6% respectively (p = 0.1197). In the Bland-Altman analysis, the mean bias between ScvO2 and SmO2 was 2.8% +/- 12.3% with 95% limits of agreement of -21.3% to 26.9%. More than 60% of the ScvO2 and SmO2 values diverged by ≥ 5%. CONCLUSIONS: The difference between the mean SmO2 and ScvO2 was not statistically significant and the mean bias between SmO2 and ScvO2 is low. Despite this, the substantially large standard deviation and limits of agreement preclude the use of SmO2 as a direct surrogate of ScvO2.

LAWS: Local alignment for water sites-Tracking ordered water in simulations.

Accurate modeling of protein-water interactions in molecular dynamics (MD) simulations is important for understanding the molecular basis of protein function. Data from x-ray crystallography can be useful in assessing the accuracy of MD simulations, in particular, the locations of crystallographic water sites (CWS) coordinated by the protein. Such a comparison requires special methodological considerations that take into account the dynamic nature of proteins. However, existing methods for analyzing CWS in MD simulations rely on global alignment of the protein onto the crystal structure, which introduces substantial errors in the case of significant structural deviations. Here, we propose a method called local alignment for water sites (LAWS), which is based on multilateration-an algorithm widely used in GPS tracking. LAWS considers the contacts formed by CWS and protein atoms in the crystal structure and uses these interaction distances to track CWS in a simulation. We apply our method to simulations of a protein crystal and to simulations of the same protein in solution. Compared with existing methods, LAWS defines CWS characterized by more prominent water density peaks and a less-perturbed protein environment. In the crystal, we find that all high-confidence crystallographic waters are preserved. Using LAWS, we demonstrate the importance of crystal packing for the stability of CWS in the unit cell. Simulations of the protein in solution and in the crystal share a common set of preserved CWS that are located in pockets and coordinated by residues of the same domain, which suggests that the LAWS algorithm will also be useful in studying ordered waters and water networks in general.

Influenza A virus infection disrupts oligodendrocyte homeostasis and alters the myelin lipidome in the adult mouse.

BACKGROUND: Recent data suggest that myelin may be altered by physiological events occurring outside of the central nervous system, which may cause changes to cognition and behavior. Similarly, peripheral infection by non-neurotropic viruses is also known to evoke changes to cognition and behavior. METHODS: Mice were inoculated with saline or influenza A virus. Bulk RNA-seq, lipidomics, RT-qPCR, flow cytometry, immunostaining, and western blots were used to determine the effect of infection on OL viability, protein expression and changes to the lipidome. To determine if microglia mediated infection-induced changes to OL homeostasis, mice were treated with GW2580, an inhibitor of microglia activation. Additionally, conditioned medium experiments using primary glial cell cultures were also used to test whether secreted factors from microglia could suppress OL gene expression. RESULTS: Transcriptomic and RT-qPCR analyses revealed temporal downregulation of OL-specific transcripts with concurrent upregulation of markers characteristic of cellular stress. OLs isolated from infected mice had reduced cellular expression of myelin proteins compared with those from saline-inoculated controls. In contrast, the expression of these proteins within myelin was not different between groups. Similarly, histological and immunoblotting analysis performed on various brain regions indicated that infection did not alter OL viability, but increased expression of a cellular stress marker. Shot-gun lipidomic analysis revealed that infection altered the lipid profile within the prefrontal cortex as well as in purified brain myelin and that these changes persisted after recovery from infection. Treatment with GW2580 during infection suppressed the expression of genes associated with glial activation and partially restored OL-specific transcripts to baseline levels. Finally, conditioned medium from activated microglia reduced OL-gene expression in primary OLs without altering their viability. CONCLUSIONS: These findings show that peripheral respiratory viral infection with IAV is capable of altering OL homeostasis and indicate that microglia activation is likely involved in the process.

C-C Bond Activation and Demethylenation of Epoxides by Amine Radical Dications.

In this note, we explore a unique reactivity pattern that involves a rare radical-based C-C bond scission of epoxides followed by demethylenation. The reaction is accomplished by Selecfluor and its radical dication working in tandem; a mechanism supported by experiment and DFT calculations is proposed that involves the generation and identification of a key reactive intermediate. The reaction seems to be fairly general for 1,1-disubstituted epoxides.

Pediatric Patient and Caregiver Satisfaction With the Use of Transabdominal Bowel Ultrasound in the Assessment of Inflammatory Bowel Diseases.

OBJECTIVES: Transabdominal bowel ultrasound (TABUS) is emerging as an attractive, noninvasive tool in inflammatory bowel disease (IBD). Patient and caregiver experience with TABUS is not well described. We aimed to determine pediatric patient and caregiver satisfaction with TABUS and the impact of IBD severity, gender, age, and a history of anxiety on satisfaction. METHODS: Pediatric patients (0-18 years old) with suspected IBD prospectively underwent baseline TABUS, magnetic resonance enterography (MRE), blood work, stool studies, and endoscopy. Patients and their caregiver each completed a cross-sectional satisfaction questionnaire (5-point Likert scale) after the baseline investigations. RESULTS: There were 54 patients included (67% male). The majority were completely satisfied and strongly agree TABUS was better tolerated than other investigations, regardless of disease severity ( P > 0.05). Patients with higher Simple Endoscopic Score for Crohn Disease (SES-CD) scores felt that TABUS increased their understanding of their IBD ( P < 0.05) and disease location ( P < 0.05). Patients with Crohn disease had similar responses to those with ulcerative colitis, but more strongly agreed that TABUS was better than MRE and endoscopy ( P < 0.05). Those with anxiety did not have an increased level of worry about potential ultrasound findings ( P > 0.05). CONCLUSIONS: Pediatric patients and their caregivers were highly satisfied with TABUS, preferring it to other modalities. It did not lead to increased worry, and was particularly important in those with severe IBD. These findings support wider implementation of this well tolerated and preferred monitoring tool in pediatrics.

Eliciting Low-Risk Thyroid Cancer Treatment Preferences Using Clinical Vignettes: A Pilot Study.

OBJECTIVE: While surgical resection has been the traditional standard treatment for small (≤1 cm), differentiated thyroid cancers, active surveillance (AS) and radiofrequency ablation (RFA) are increasingly considered. The aim of this study was to explore patient preferences in thyroid cancer treatment using a series of clinical vignettes. METHODS: Thyroid cancer survivors and general population volunteers were recruited to rank experience-driven clinical vignettes in order of preference. Rankings were compared using Wilcoxon signed rank. Formative qualitative methods were used to develop and refine clinical vignettes that captured 4 treatments-thyroid lobectomy (TL), total thyroidectomy (TT), AS, and RFA-along with 6 treatment complications. Content was validated via interviews with 5 academic subspecialists. RESULTS: Nineteen volunteers participated (10 survivors, 9 general population). Treatment complications were ranked lower than uncomplicated counterparts in 99.0% of cases, indicating excellent comprehension. Counter to our hypothesis, among uncomplicated vignettes, median rankings were 1 for AS, 2 for RFA, 3.5 for TL, and 5 for TT. Trends were consistent between thyroid cancer survivors and the general population. AS was significantly preferred over RFA (P = .02) and TT (P < .01). Among surgical options, TL was significantly preferred over TT (P < .01). CONCLUSION: When treatments for low-risk thyroid cancer are described clearly and accurately through clinical vignettes, patients may be more likely to choose less invasive treatment options over traditional surgical resection.

Rising of LOXHD1 as a signature causative gene of down-sloping hearing loss in people in their teens and 20s.

BACKGROUND: Down-sloping sensorineural hearing loss (SNHL) in people in their teens and 20s hampers efficient learning and communication and in-depth social interactions. Nonetheless, its aetiology remains largely unclear, with the exception of some potential causative genes, none of which stands out especially in people in their teens and 20s. Here, we examined the role and genotype-phenotype correlation of lipoxygenase homology domain 1 (LOXHD1) in down-sloping SNHL through a cohort study. METHODS: Based on the Seoul National University Bundang Hospital (SNUBH) genetic deafness cohort, in which the patients show varying degrees of deafness and different onset ages (n=1055), we have established the 'SNUBH Teenager-Young Adult Down-sloping SNHL' cohort (10-35 years old) (n=47), all of whom underwent exome sequencing. Three-dimensional molecular modelling, minigene splicing assay and short tandem repeat marker genotyping were performed, and medical records were reviewed. RESULTS: LOXHD1 accounted for 33.3% of all genetically diagnosed cases of down-sloping SNHL (n=18) and 12.8% of cases in the whole down-sloping SNHL cohort (n=47) of young adults. We identified a potential common founder allele, as well as an interesting genotype-phenotype correlation. We also showed that transcript 6 is necessary and probably sufficient for normal hearing. CONCLUSIONS: LOXHD1 exceeds other genes in its contribution to down-sloping SNHL in young adults, rising as a signature causative gene, and shows a potential but interesting genotype-phenotype correlation.

Synthesis of push-pull-activated ynol ethers and their evaluation in the bioorthogonal hydroamination reaction.

A new class of push-pull-activated alkynes featuring di- and trifluorinated ynol ethers was synthesized. The difluorinated ynol ether exhibited an optimal balance of stability and reactivity, displaying a substantially improved half-life in the presence of aqueous thiols over the previously reported 1-haloalkyne analogs while reacting just as fast in the hydroamination reaction with N,N-diethylhydroxylamine. The trifluorinated ynol ether reacted significantly faster, exhibiting a second order rate constant of 0.56 M-1 s-1 in methanol, but it proved too unstable toward thiols. These fluorinated ynol ethers further demonstrate the importance of the hyperconjugation-rehybridization effect in activating alkynes and demonstrate how substituent effects can both activate and stabilize alkynes for bioorthogonal reactivity.

Artificial urinary sphincter cuffs and safe instrument/catheter passage guidelines.

PURPOSE: The artificial urinary sphincter (AUS) is the gold standard for males with urinary incontinence. It is generally a safe procedure with a high degree of satisfaction. However, there is a lifelong risk of infection and erosion. AUS cuffs are commonly placed around the bulbar urethral area. There is always a risk of trauma and erosion of cuffs with catheterization or endoscopy. At this time, there is little guidance as to which size catheters or scopes can pass through each AUS cuff sizes safely. The goal of this study was to determine which size of catheters/scopes can pass through different cuff sizes safely in an ex vivo setting. METHOD: All AUS cuff sizes available (3.5 cm up to 6.0 cm), catheter sizes between 12 and 22 Fr, and scope sizes 19 Fr flexible/rigid, 21-26 Fr rigid scopes were examined. We used deflated assembled cuffs on the bench (ex vivo) and three different blind observers to measure the free space left between the wall of the cuff and the catheter/scope to be sure that there was consistency. We created a scale from 1 to 3 to determine the ease of passage for each catheter/scope. We also had an MRI radiologist examine bulbar urethra thickness in 20 male patients to determine the average thickness without the bulbospongiosus muscle. Using our average bulbar urethral thickness, we were able to estimate how much free space remained within the urethral lumen and how easy and safe it was to pass each catheter/scope. RESULTS: For 3.5 cm cuffs, 12 Fr catheters pass easily and safely, 14-16 Fr catheters and 19 Fr flexible/rigid scopes can pass through with some mild risk of trauma. Larger catheter/scope sizes cannot pass through without a significant risk of trauma. For 4.0 cm cuffs, 12-14 Fr catheters pass easily and safely. 16-18 Fr catheters and 19-21 Fr rigid/flexible scopes can pass with some mild risk of trauma. Larger catheter/scope sizes cannot pass through safely. For 4.5 cm cuffs, 12-18 Fr catheters and 19 Fr flexible/rigid scopes pass easily and safely. 20-22 Fr catheters and 21 Fr rigid scopes can pass with some mild risk of trauma. Larger catheter/scope sizes cannot pass through safely. For 5.0 cm cuffs, 12-22 Fr catheters and 19-21 Fr flexible/rigid scopes can pass easily and safely. 22-26 Fr scopes can pass with some mild risk of trauma. For 5.5 cm cuffs, all catheters/scopes can pass easily and safely. However, the 26 Fr rigid scope can pass with some mild risk of trauma. For 6 cm cuffs, all catheters/scopes examined can pass easily and safely. CONCLUSION: Our study can guide urologists in the management of patients with an AUS who need urethral catheters or endoscopy. These recommendations are based on the measurements of our study along with bulbar urethral thickness. In general, greater caution is needed with smaller cuff sizes (3.5-4.5 cm). Our recommendations, with minimal urethral compression, are purposely conservative and safe to avoid trauma and erosion of the AUS cuffs.