Cetylpyridinium Chloride Mouthwash to Reduce Shedding of Infectious SARS-CoV-2: A Double-Blind Randomized Clinical Trial.

The airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via respiratory fluids and droplets suggests that mouthwashes containing substances with virucidal activity can help reduce viral spread. We conducted a multicenter, double-blind, placebo-controlled, randomized trial to assess the virucidal activity of cetylpyridinium chloride (CPC) mouthwashes. Outpatients who tested positive for SARS-CoV-2 infection with or without symptoms were randomized to perform washes and gargles for 1 min with 15 mL of either colored distilled water or 0.07% CPC (Vitis CPC Protect) mouthwash. The study outcomes were the SARS-CoV-2 log10 viral RNA load and the nucleocapsid protein levels, both in saliva at 1 and 3 h after the intervention. In total, 118 patients were enrolled and randomized (mean [SD], age 46 [14] y). Thirteen of 118 participants (11%) did not complete follow-up or had insufficient sample volume for testing and were excluded from the analysis. The assessment of the viral load showed no significant differences between groups at any of the investigated points. However, the levels of SARS-CoV-2 nucleocapsid protein of lysed viruses were significantly higher in the CPC group compared with the control group at 1 h (adjusted difference 269.3 pg/mL; 95% confidence interval [CI], 97.1-441.5) and at 3 h postintervention (561.1 pg/mL; 95% CI, 380.0-742.2). In nonhospitalized patients with asymptomatic or mild symptomatic SARS-CoV-2 infection, a 0.07% CPC mouthwash, compared to placebo, was associated with a significant increase of nucleocapsid protein levels in saliva, indicating enhanced disruption of viral particles.

Viral and inflammatory markers in cerebrospinal fluid of patients with HIV-1-associated neurocognitive impairment during antiretroviral treatment switch.

OBJECTIVES: The aim of the study was to evaluate HIV-1 viral load (VL) and inflammatory markers in cerebrospinal fluid (CSF) and neurocognitive performance in patients with neurocognitive impairment (NCI) while they were receiving tenofovir (TDF)/ emtricitabine (FTC)/efavirenz (EFV) and after switching to a regimen with enhanced central nervous system (CNS) penetrability. METHODS: This was a prospective, single-arm pilot study. HIV-1-infected patients with plasma viral suppression and HIV-associated NCI on a regimen including TDF/FTC/EFV were switched to abacavir (ABC)/lamivudine (3TC)/maraviroc (MVC). The Global Deficit Score (GDS) was used to score cognitive function at baseline and 48 weeks after treatment switch. Both CSF and blood samples were taken at baseline and between weeks 24 and 36 after switching. HIV-1 RNA in plasma and CSF was determined by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Inflammatory biomarkers in CSF were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: A total of 71 patients receiving TDF/FTC/EFV were screened. Twelve of them (17%) had documented NCI, lacked the human leucocyte antigen (HLA)-B*57:01 haplotype and harboured Chemokine Receptor Type-5 (CCR5)-tropic virus. Eight patients had detectable HIV-1 RNA (between 2.7 and 41.6 HIV-1 RNA copies/mL) in CSF at baseline. All participants had elevated levels of neopterin and Monocyte Chemoattractant Protein 1 (MCP-1) in CSF at baseline. Eight out of 12 patients completed their follow-up assessment after treatment switch. The GDS decreased from 0.55 to 0.4 (P = 0.085). Median HIV-1 RNA in CSF decreased from 3.49 to 2.20 (P = 0.23). Among the inflammation markers in CSF, tumour necrosis factor (TNF)-α decreased significantly from median 0.51 to 0.35 pg/mL (P = 0.027), showing a correlation with the changes in neopterin, interferon (IFN)-γ and interleukin (IL)-6. CONCLUSIONS: Most patients with NCI receiving TDF/FTC/EFV had low-level viraemia and/or increased inflammatory markers in CSF. Treatment switching to an MVC-containing regimen with better CNS penetration resulted in a trend towards improvement in neurocognitive status and reduced TNF-α concentrations in CSF.

Chemiluminescent aldehyde and beta-diketone reactions promoted by peroxynitrite.

Peroxynitrite is shown here to promote the aerobic oxidation of isobutanal (IBAL) and 3-methyl-2,4-pentanedione (MP) in a pH 7.2 phosphate buffer into acetone plus formate and biacetyl plus acetate, respectively. These products are expected from dioxetane intermediates, whose thermolysis is known to be chemiluminescent (CL). Accordingly, the extent of total oxygen uptake by IBAL at different concentrations parallels the corresponding CL maximum intensities. The pH profile based on oxygen uptake data for the MP reaction matches the titration curve of peroxynitrous acid (pK(a) approximately 7), indicating that peroxynitrite anion is the oxidizing agent. Energy transfer studies with IBAL and the 9, 10-dibromoanthracene-2-sulfonate ion, a triplet carbonyl detector, indicates that triplet acetone (tau = 19 micros) is the energy donor. It is postulated that IBAL- or MP-generated triplet carbonyls are produced by the thermolysis of dioxetane intermediates, which are formed by the cyclization of alpha-hydroperoxide intermediates produced by insertion of dioxygen into the IBAL or MP enolyl radicals, followed by their reduction. Accordingly, EPR spin-trapping studies with 3,5-dibromo-4-nitrosobenzenesulfonic acid (DBNBS) and 2-methyl-2-nitrosopropane (MNP) revealed the intermediacy of carbon-centered radicals, as expected for one-electron abstraction from the enol forms of IBAL or MP by peroxynitrite. The EPR data obtained with IBAL also reveal formation of the isopropyl radical produced by competitive nucleophilic addition of ONOO(-) to IBAL, followed by homolytic cleavage of this adduct and beta-scission of the resulting Me(2)CHCH(O(-))O(*). Superstoichiometric formation of fragmentation products from IBAL or MP attests to the prevalence of an autoxidation chain reaction, here proposed to be initiated by one-electron abstraction by ONOO(-) from the substrate. This work reveals the potential role of peroxynitrite as a generator of electronically excited species that may contribute to deleterious and pathological processes associated with excessive nitric oxide and aldehyde production.

Oxidation of acetaldehyde by peroxynitrite and hydrogen Peroxide/Iron(II). Production Of acetate, formate, and methyl radicals.

Production of free radicals from acetaldehyde oxidation by enzymes and cellular fractions is a well-known process. The toxic effects of acetaldehyde, however, are usually attributed to its reactions with biomolecules to produce adducts. Here, we demonstrate that hypothetical adducts produced from attack of acetaldehyde by two important biological oxidants, peroxynitrite and hydrogen peroxide, decompose to produce acetate, formate, and methyl radicals. Acetate, formate, nitrate, and nitrite were characterized and quantified by capillary electrophoresis. Radicals were detected and quantified by the EPR spectra produced in the presence of spin traps 3, 5-dibromo-4-nitrosobenzenesulfonic acid and 5,5-dimethyl-1-pyrroline N-oxide. Kinetic studies and product analysis were performed at different pHs. The results demonstrate that production of methyl radicals during oxidation of acetaldehyde by hydrogen peroxide was strictly dependent on the presence of iron(II) and occurred via two routes. One involved acetaldehyde attack by the hydroxyl radical to produce the acetyl radical that decomposes to methyl radical and carbon monoxide. The other route involved acetaldehyde attack by deprotonated hydrogen peroxide to produce a hypothetical intermediate that reductively cleaves via the action of present iron(II) to produce radicals. The latter mechanism predominates in the case of peroxynitrite, but radical formation does not require metal ions. Most of the hypothetical adduct produced from acetaldehyde and peroxynitrite (k = 680 M(-)(1) s(-)(1) at pH 7.4 and 37 degrees C) decays to nitrate and regenerates the aldehyde [Uppu, R. M., et al. (1997) Chem. Res. Toxicol. 10, 1331], but about 30% of it produces acetate, formate, and methyl radicals. Part of these oxidized products result from beta-scission and 1,2-shift reactions of the 1-hydroxyethoxyl radical which, together with nitrogen dioxide, freely diffuses from the adduct (20% yields). The results provide yet another example of the metal-independent free radical reactivity of peroxynitrite and may be relevant to the toxic effects associated with heavy drinking and diabetes.