Complex Endovascular Repair of Paravisceral Infective Native Aortic Aneurysms.

OBJECTIVE: To report the early and mid-term outcome of complex endovascular repair (EVAR) for paravisceral infective native aortic aneurysms (INAA). METHODS: Interrogation of a prospectively maintained database identified consecutive patients who underwent non-elective complex EVAR for paravisceral INAAs in a single institution between December 2013 and June 2020. All patients were considered to have definite INAAs based on diagnostic criteria. Patients who had prior aortic repair were excluded. RESULTS: A total of 26 patients (19 men; mean age 67 years [SD = 11.4]; median diameter 60 mm [IQR: 55-73]) with acute symptomatic (n = 24) or contained ruptured (n = 2) aneurysms underwent surgeon-modified fenestrated EVAR (SM-FEVAR; n = 24) or chimney-periscope EVAR (CHIMPS; n = 2). Median observed follow-up was 36.2 months (18.3-53.5). Nine patients had positive venous blood cultures and a further seven had recent or concomitant infection. All patients received pre- and post-operative antibiotic therapy and rifampicin-soaked endografts. A total of 95 vessels were targeted for preservation and 86 were stent-grafted. One vessel occluded intra-operatively and a further 3 occluded within 30 days. The 30-day/in-hospital mortality was 11.5% (n = 3), and the estimated 1- and 3-year survival (±SD) was 85% ± 7%. Infection-related complications (IRCs) occurred in two patients: both developed new INAA within 30 days of index repair and were treated by EVAR with no mortality. Estimated 3-year freedom from late re-intervention was 100%. One patient required infrarenal EVAR for a non-infective aneurysm at 43 months. CONCLUSION: Complex EVAR for paravisceral INAAs is associated with acceptable early and mid-term outcomes and is an acceptable alternative to open surgery. We propose that these patients are managed with long-term antimicrobials, impregnation of graft material with rifampicin, and rigorous post-operative surveillance. CLINICAL IMPACT: A multi-disciplinary approach is required to deliver the best possible outcome for patients with this challenging aortic pathology.

Virtual screening and molecular dynamics simulation study of approved drugs as a binder to the linoleic acid binding site on spike protein of SARS-CoV-2 and double mutant (E484Q and L452R).

INTRODUCTION: Binding of linoleic acid (LA) to the spike trimer stabilizes it in closed conformation hindering its binding to angiotensin-converting enzyme-2, thus decreasing infectivity. In the current study, we tend to repurpose Food and Drug Administration-approved drugs as binder to the LA binding pocket in wild and double mutant spike protein. MATERIALS AND METHODS: Approved drugs from DrugBank database (n = 2456) were prepared using Ligprep module of Schrodinger. Crystal structure of LA bound to spike trimer was retrieved (PDB: 6ZB4) and prepared using protein preparation wizard and grid was generated. A virtual screening was performed. With the help of molecular dynamics (MD) studies interaction profile of screened drugs were further evaluated. The selected hits were further evaluated for binding to the double mutant form of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). RESULTS AND DISCUSSION: Following virtual screening, a total of 26 molecules were shortlisted, which were further evaluated using 1ns MD simulation study. Four ligands showing better root mean square deviation (RMSD), RMSD to LA with interaction profile similar to LA were further evaluated using 100 ns MD simulation studies. A total of 2 hits were identified, which performed better than LA (selexipag and pralatrexate). Both these ligands were also found to bind to LA binding site of the double mutant form (E484Q and L452R); however, the binding affinity of pralatrexate was found to be better. CONCLUSION: We have identified 2 ligands (selexipag and pralatrexate) as possible stable binders to the LA binding site in spike trimer (wild and mutant form). Among them, pralatrexate has shown in vitro activity against SARS-CoV-2, validating our study results.

Outcomes From Routine Use of Intraoperative Cholangiogram in Laparoscopic Cholecystectomy: Factors Predicting Benefit From Selective Cholangiography.

Background and objective Laparoscopic cholecystectomy is used for the treatment of symptomatic gallstones. Intraoperative cholangiogram (IOC) is used to diagnose common bile duct (CBD) stones. There is controversy surrounding routine vs selective use of IOC based on clinical, biochemical and ultrasound criteria. The aim of this study was to evaluate the outcomes from routine IOC and its utility in laparoscopic cholecystectomy. Materials and methods This was a UK-based single-centre retrospective study evaluating the outcomes from IOC for all laparoscopic cholecystectomies performed between May 2014 and February 2020. All adult patients undergoing elective, semi-elective or emergency operations were included. Demographics, biochemistry as well as radiological and endoscopic investigations were analysed. IOC was performed using a standardised technique and was interpreted by a single surgeon. Results A total of 744 out of 804 patients underwent IOC. The median age of the cohort was 51 years (SD: ±17.5); there were 468 females (62.9%) and 276 males (37.1%). Filling defects were identified in 43/744 (5.8%) patients, with 23/43 having stone extraction via endoscopic retrograde cholangiopancreatography (ERCP). Logistic regression analysis identified alkaline phosphatase (ALP) as a predictor of filling defects in IOC (OR: 1.003; 95% CI: 1.001-1.005, p=0.015). Conclusion Based on our findings, the routine use of IOC during laparoscopic cholecystectomy is safe and effective. Preoperative clinical, radiological and biochemical parameters apart from ALP have a limited role in predicting the diagnostic yield of IOC.

Immunoinformatic evaluation of multiple epitope ensembles as vaccine candidates: E coli 536.

Epitope prediction is becoming a key tool for vaccine discovery. Prospective analysis of bacterial and viral genomes can identify antigenic epitopes encoded within individual genes that may act as effective vaccines against specific pathogens. Since B-cell epitope prediction remains unreliable, we concentrate on T-cell epitopes, peptides which bind with high affinity to Major Histacompatibility Complexes (MHC). In this report, we evaluate the veracity of identified T-cell epitope ensembles, as generated by a cascade of predictive algorithms (SignalP, Vaxijen, MHCPred, IDEB, EpiJen), as a candidate vaccine against the model pathogen uropathogenic gram negative bacteria Escherichia coli (E-coli) strain 536 (O6:K15:H31). An immunoinformatic approach was used to identify 23 epitopes within the E-coli proteome. These epitopes constitute the most promiscuous antigenic sequences that bind across more than one HLA allele with high affinity (IC50 < 50nM). The reliability of software programmes used, polymorphic nature of genes encoding MHC and what this means for population coverage of this potential vaccine are discussed.