Discovery of Di- and Trihaloacetamides as Covalent SARS-CoV-2 Main Protease Inhibitors with High Target Specificity.

The main protease (Mpro) is a validated antiviral drug target of SARS-CoV-2. A number of Mpro inhibitors have now advanced to animal model study and human clinical trials. However, one issue yet to be addressed is the target selectivity over host proteases such as cathepsin L. In this study we describe the rational design of covalent SARS-CoV-2 Mpro inhibitors with novel cysteine reactive warheads including dichloroacetamide, dibromoacetamide, tribromoacetamide, 2-bromo-2,2-dichloroacetamide, and 2-chloro-2,2-dibromoacetamide. The promising lead candidates Jun9-62-2R (dichloroacetamide) and Jun9-88-6R (tribromoacetamide) had not only potent enzymatic inhibition and antiviral activity but also significantly improved target specificity over caplain and cathepsins. Compared to GC-376, these new compounds did not inhibit the host cysteine proteases including calpain I, cathepsin B, cathepsin K, cathepsin L, and caspase-3. To the best of our knowledge, they are among the most selective covalent Mpro inhibitors reported thus far. The cocrystal structures of SARS-CoV-2 Mpro with Jun9-62-2R and Jun9-57-3R reaffirmed our design hypothesis, showing that both compounds form a covalent adduct with the catalytic C145. Overall, these novel compounds represent valuable chemical probes for target validation and drug candidates for further development as SARS-CoV-2 antivirals.

Implementation of an Inpatient IBD Service Is Associated with Improvement in Quality of Care and Long-Term Outcomes.

BACKGROUND: There is wide variation in the quality of care of hospitalized patients with inflammatory bowel disease (IBD). Prior studies have demonstrated that a specialized inpatient IBD service improves short-term outcomes. In this study, we assessed the impact of a dedicated IBD service on the quality of care and long-term outcomes. METHODS: This retrospective cohort study included adult patients admitted for a complication of IBD between March 2017 and February 2019 to a tertiary referral center. In March 2018, a dedicated inpatient IBD service co-managed by IBD gastroenterologists and colorectal surgeons was implemented. Quality of care outcomes included C. difficile stool testing, confirmed VTE prophylaxis administration and opiate avoidance. Long-term outcomes were clinical remission, IBD-related surgery, ED visits, and hospital readmissions at 90 days and 12 months. RESULTS: In total, 143 patients were included; 66 pre- and 77 post-implementation of the IBD service. Fifty-two percent had ulcerative colitis and 48% had Crohn's disease. After implementation, there was improvement in C.difficile testing (90% vs. 76%, P = 0.04), early VTE prophylaxis (92% vs. 77%, P = 0.01) and decreases in narcotic use (14% vs. 30%, P = 0.02), IBD-related ED visits at 90 days (7% vs 18%, P = 0.03) and 12 months (16% vs 30%, P = 0.04), and IBD readmissions at 90 days (16% vs. 30%, P = 0.04). There were no differences in rates of clinical remission or surgery. CONCLUSIONS: The creation of a dedicated inpatient IBD service improved quality of IBD care and reduced post-discharge ED visits and readmissions and broader implementation of this strategy may help optimize care of hospitalized IBD patients.

Alvimopan for the Prevention of Postoperative Ileus in Inflammatory Bowel Disease Patients.

BACKGROUND: Postoperative ileus (POI) is a temporary delay of coordinated intestinal peristalsis. Alvimopan, an oral peripherally acting mu-opioid receptor antagonist approved for accelerating gastrointestinal recovery, has never been studied specifically in patients with inflammatory bowel disease (IBD). AIM: To investigate the efficacy of alvimopan in preventing POI among IBD patients. METHODS: A retrospective chart review was conducted on 246 IBD patients undergoing bowel surgery between 2012 and 2017. Data collected included demographics, IBD subtype, length of stay (LOS), postoperative gastrointestinal symptoms, and administration of alvimopan. The primary outcome was POI; secondary gastrointestinal recovery outcomes were: time to first flatus, time to first bowel movement, time to tolerating a liquid diet, time to tolerating solid food, and LOS. RESULTS: When compared with the control group, patients in the alvimopan group had shorter times to tolerating liquids and solids, first flatus, and first bowel movements (p < 0.01). LOS was shorter in the alvimopan group when compared with controls (p < 0.01). The overall incidence of POI was higher in controls than in the alvimopan group (p = 0.07). For laparoscopic surgeries, the incidence of POI was also higher in controls than in the alvimopan group (p < 0.01). On multivariable analysis, alvimopan significantly decreased time to all gastrointestinal recovery endpoints when compared to controls (p < 0.01). CONCLUSIONS: Alvimopan is effective in accelerating time to gastrointestinal recovery and reducing POI in IBD patients. While the benefits of alvimopan have been demonstrated previously, this is the first study of the efficacy of alvimopan in IBD patients.

Combinatorial synthesis of chemically diverse core-shell nanoparticles for intracellular delivery.

Analogous to an assembly line, we employed a modular design for the high-throughput study of 1,536 structurally distinct nanoparticles with cationic cores and variable shells. This enabled elucidation of complexation, internalization, and delivery trends that could only be learned through evaluation of a large library. Using robotic automation, epoxide-functionalized block polymers were combinatorially cross-linked with a diverse library of amines, followed by measurement of molecular weight, diameter, RNA complexation, cellular internalization, and in vitro siRNA and pDNA delivery. Analysis revealed structure-function relationships and beneficial design guidelines, including a higher reactive block weight fraction, stoichiometric equivalence between epoxides and amines, and thin hydrophilic shells. Cross-linkers optimally possessed tertiary dimethylamine or piperazine groups and potential buffering capacity. Covalent cholesterol attachment allowed for transfection in vivo to liver hepatocytes in mice. The ability to tune the chemical nature of the core and shell may afford utility of these materials in additional applications.

Video Consent for Upper Endoscopy and Colonoscopy Improves Patient Comprehension in a Safety-net, Multi-lingual Population.

The challenges of consenting for procedures are well documented and are compounded when patients have limited English proficiency (LEP). Standardized video consent has been studied, but research in gastroenterology is limited. We created educational videos in English and Spanish covering the elements of traditional consent for colonoscopy and upper endoscopy. All participants underwent traditional verbal consent and a subset viewed the language and procedure specific video. Participants from a multilingual, safety-net hospital patient population were then given a questionnaire to assess their comprehension and satisfaction. Participants who watched the video had higher comprehension scores than those who received traditional verbal consent alone. This difference persisted when data was stratified by language and procedure, and when controlled for educational level and prior procedure. Video consent improves comprehension and satisfaction for endoscopy and may mitigate some of the challenges encountered when consenting patients with LEP.

Evaluation of Dysplasia in Barrett Esophagus.

Barrett esophagus (BE) is the precursor lesion to adenocarcinoma of the esophagus. The current surveillance strategy of 4-quadrant Seattle protocol biopsies has been associated with sampling error and missing higher-risk lesions, and there is often less adherence to endoscopic surveillance with long segments. Advancements in endoscopic imaging and sampling techniques allow for better surveillance of BE, particularly when assessing for dysplasia. This article highlights the key endoscopic imaging and sampling advancements in the evaluation of dysplasia in BE.