Troubleshooting Paracentesis Using POCUS.

Paracentesis is a procedure routinely performed at the bedside in the evaluation and management of ascites. While point of care ultrasound (POCUS) assistance during paracentesis is known to reduce the risk of procedure-related complications, intraprocedural POCUS to overcome commonly occurring issues, such as obstructed flow through the centesis catheter, remain poorly described. In this report, we present two cases in which bowel adhered to the catheter during paracentesis. POCUS was used in an attempt to restore flow. Based on our literature review and procedural experience, we propose an algorithm to surmount this routinely encountered problem.

Systematic and Statistical Review of Coronavirus Disease 19 Treatment Trials.

The following systematic review and meta-analysis compile the current data regarding human controlled COVID-19 treatment trials. An electronic search of the literature compiled studies pertaining to human controlled treatment trials with COVID-19. Medications assessed included lopinavir/ritonavir, arbidol, hydroxychloroquine, tocilizumab, favipiravir, heparin, and dexamethasone. Statistical analyses were performed for common viral clearance endpoints whenever possible. Lopinavir/ritonavir showed no significant effect on viral clearance for COVID-19 cases (OR 0.95 [95% CI 0.50-1.83]). Hydroxychloroquine also showed no significant effect on COVID-19 viral clearance rates (OR 2.16 [95% CI 0.80-5.84]). Arbidol showed no 7-day (OR 1.63 [95% CI 0.76-3.50]) or 14-day viral (OR 5.37 [95% CI 0.35-83.30]) clearance difference compared to lopinavir/ritonavir. Review of literature showed no significant clinical improvement with lopinavir/ritonavir, arbidol, hydroxychloroquine, or remdesivir. Tocilizumab showed mixed results regarding survival. Favipiravir showed quicker symptom improvement compared to lopinavir/ritonavir and arbidol. Heparin and dexamethasone showed improvement with severe COVID-19 cases requiring supplemental oxygenation. Current medications do not show significant effect on COVID-19 viral clearance rates. Tocilizumab showed mixed results regarding survival. Favipiravir shows favorable results compared to other tested medications. Heparin and dexamethasone show benefit especially for severe COVID-19 cases.

Novel compounds containing multiple guanide groups that bind the HIV coreceptor CXCR4.

The G-protein-coupled receptor CXCR4 acts as a coreceptor for human immunodeficiency virus type 1 (HIV-1) infection, as well as being involved in signaling cell migration and proliferation. Compounds that block CXCR4 interactions have potential uses as HIV entry inhibitors to complement drugs such as maraviroc that block the alternate coreceptor CCR5 or in cancer therapy. The peptide T140, which contains five arginine residues, is the most potent antagonist of CXCR4 developed to date. In a search for nonpeptide CXCR4 ligands that could inhibit HIV entry, three series of compounds were synthesized from 12 linear and branched polyamines with 2, 3, 4, 6, or 8 amino groups, which were substituted to produce the corresponding guanidines, biguanides, or phenylguanides. The resulting compounds were tested for their ability to compete with T140 for binding to the human CXCR4 receptor expressed on mammalian cells. The most effective compounds bound CXCR4 with a 50% inhibitory concentration of 200 nM, and all of the compounds had very low cytotoxicity. Two series of compounds were then tested for their ability to inhibit the infection of TZM-bl cells with X4 and R5 strains of HIV-1. Spermine phenylguanide and spermidine phenylguanide inhibited infection by X4 strains, but not by R5 strains, at low micromolar concentrations. These results support further investigation and development of these compounds as HIV entry inhibitors.

Computational design of a light-driven molecular motor.

Light-driven molecular motors may be useful for nanotechnology applications. The possibility of building such a motor based on the tolane framework is explored here. In the ground electronic state of tolane, the barrier to internal rotation is comparable to room temperature thermal energies, k(B)T. The barrier increases substantially in the excited state, causing the molecule to planarize after absorption of a photon. This tendency to planarize may be converted into unidirectional rotational motion by placing chiral substituents on the phenyl rings. A potential advantage of this class of motors is that they may undergo rapid, nanosecond scale rotation. Computational design of appropriate substituents was done using semiempirical quantum chemical methods, SAM1 for the ground electronic state coupled to INDO for the excitation energy. The torsional surfaces of the best candidate were then generated using ab initio DFT methods, which confirm that the molecule should undergo unidirectional rotation upon photoexcitation. The results provide a proof of principle for this class of motors; however, two aspects of the final candidate are nonideal. First, although the design goal was to use steric interactions between substituents to induce the rotation, decomposition of the interaction energy suggests attractive interactions play a role. Solvent interactions may interfere with these attractive interactions. Second, TDDFT calculations suggest that interactions between excited states lower the rotational driving force in the excited state.