Biology subjects

Jordan, W.

Publications and source records attributed to Jordan, W..

6 recordsLinked to original sources

bioRxiv2025

Inactivation of Airborne Pathogen Surrogates by Triethylene Glycol

The COVID-19 outbreak brought to the fore the importance of airborne transmission in spreading human infectious diseases and highlighted the need for sustainable mitigation strategies. Triethylene glycol (TEG) has been documented as having microbicidal capabilities and has been proposed as one such mitigation strategy. Aerosolized TEG exhibits antimicrobial activity against airborne microorganisms; Grignard Pure Technology was developed to safely aerosolize TEG for decontamination of enclosed spaces. Here we show that this TEG formulation effectively inactivates airborne microorganisms, resulting in 2 to 4.5 net log reduction in concentration of viable bacteria, viruses, and mycobacteria within 30-60 minutes at TEG concentration (aerosol + vapor) of [~]0.7 mg/m3, which is well within the range considered safe for humans. Our data also demonstrate that aerosolizing both the test organisms and the antimicrobial product provides a more accurate and relevant measure of the products efficacy for indoor usage than traditional surface - or solution - based disinfection assays. Accurate evaluation of antimicrobial efficacy is a crucial step in adopting novel interventions and tools to control airborne pathogens that pose a public health risk. Our findings argue that testing protocols must match the intended use of any intervention. Given the safety concerns of aerosolizing human pathogens for direct testing of airborne infectious burden, we also advance an approach for selecting suitable surrogate microorganisms based on their phenotypic and biophysical similarity to corresponding pathogenic species. ImportanceDuring the COVID-19 pandemic, personal protective equipment, social distancing, and even vaccinations proved sub-optimal in controlling the spread of COVID-19. Public health practice and the hierarchy of controls emphasize primary prevention, whereby the pathogen is removed or destroyed before exposure to the public. Triethylene glycol (TEG) has the potential to inactivate airborne pathogens and limit their spread. TEG is designated a "safer chemical" by the US EPA and has been used for decades in aerosol deodorizers and theatrical special effects. This study shows that aerosolized TEG is highly effective at eliminating a wide spectrum of viable airborne pathogen surrogates at concentrations well below the threshold of safety concern. Thus, it may afford significant protection against the transmission of infectious agents with pandemic potential.

microbiology↗

bioRxiv2022

The efficiency of Grignard Pure™ to inactivate airborne SARS-CoV-2 surrogate

Grignard Pure (GP) is a unique and proprietary blend of Triethylene Glycol (TEG) and inert ingredients designed for continuous antimicrobial treatment of air. GP received approval from the US EPA under its Section 18 Public Health Emergency Exemption program for use in seven states. This study characterizes the efficacy of GP for inactivating MS2 bacteriophage - a non-enveloped virus widely used as a surrogate for SARs-CoV-2. Experiments measured the decrease in the airborne viable MS2 concentration in the presence of different concentrations of GP from 60 to 90 minutes, accounting for both natural die-off and settling of MS2. Experiments were conducted both by introducing GP aerosol into air containing MS2 and by introducing airborne MS2 into air containing GP aerosol. GP is consistently able to rapidly reduce viable MS2 bacteriophage concentration by 2-3 logs at GP concentrations of 0.02 mg/m3 to 0.5 mg/m3 (corresponding to TEG concentrations of 0.012 mg/m3 to 0.287 mg/m3). Related GP efficacy experiments by the US EPA, as well as GP (TEG) safety and toxicology, are also discussed. SynopsisLimited research on the germicidal properties of triethylene glycol against airborne pathogens was conducted during the 1940s and 50s. This paper investigates the inactivation rate of airborne bacteriophage MS2 by Grignard Pure product, containing a unique and proprietary blend of Triethylene Glycol (TEG) and inert ingredients.

microbiology↗

bioRxiv2022

NRX-101, A RAPID-ACTING ANTI-DEPRESSANT, DOES NOT CAUSE NEUROTOXICITY FOLLOWING KETAMINE ADMINISTRATION IN PRECLINICAL MODELS

BackgroundNMDA (N-Methyl-D aspartate) receptor antagonists have gained increasing attention as rapid-acting antidepressants. However, their use has been limited by potential neurotoxicity (Olney Lesions) and recent FDA guidance requires demonstration of safety on histologic parameters prior to initiation of human studies. D-cycloserine is a mixed NMDA agonist/antagonist awarded Breakthrough Therapy Designation and currently in clinical trials for the treatment of bipolar depression with suicidal ideation. The current study was designed to investigate the neurologic safety profile of D-cycloserine by itself and in combination with ketamine and lurasidone. MethodsSprague Dawley female rats (n=106) were randomly divided into 7 study groups. Ketamine was administered via tail vein infusion. D-cycloserine and lurasidone were administered via oral gavage in escalating doses to a maximum of 2000 mg/kg DCS. To ascertain toxicity, dose escalation with three different doses of D-cycloserine/lurasidone was given in combination with ketamine. MK-801, a known neurotoxic NMDA antagonist, was administered as a positive control. Brain tissue was sectioned and stained with H&E and Fluorojade stains. ResultsNo fatalities were observed in any group. No microscopic abnormalities were found in the brain of animal subjects given ketamine, ketamine followed by DCS/lurasidone, or DCS/lurasidone alone. Neuronal necrosis, as expected, was seen in the MK-801 positive control group. ConclusionNRX-101, a fixed-dose combination of D-cycloserine/lurasidone, when administered with or without prior infusion of IV ketamine was tolerated and did not induce neurotoxicity, even at maximum-tolerated doses of D-cycloserine. HIGHLIGHTSO_LINRX-101, a fixed dose combination of D-cycloserine and lurasidone does not exhibit histologic neurotoxicity, even at maximum-tolerated doses C_LI

pharmacology and toxicology↗

bioRxiv2022

Sentinel Cards Provide Practical SARS-CoV-2 Monitoring in School Settings

Accurate, high-resolution environmental monitoring of SARS-CoV-2 traces indoors through sentinel cards is a promising approach to help students safely return to in-person learning. Because SARS-CoV-2 RNA can persist for up to a week on several indoor surface types, there is a need for increased temporal resolution to determine whether consecutive surface positives arise from new infection events or continue to report past events. Cleaning sentinel cards after sampling would provide the needed resolution, but might interfere with assay performance. We tested the effect of three cleaning solutions (BZK wipes, wet wipes, RNase Away) at three different viral loads: "high" (4 x 104 GE/mL), "medium" (1 x 104 GE/mL), and "low" (2.5 x 103 GE/mL). RNAse Away, chosen as a positive control, was the most effective cleaning solution on all three viral loads. Wet wipes were found to be more effective than BZK wipes in the medium viral load condition. The low viral load condition was easily reset with all three cleaning solutions. These findings will enable temporal SARS-CoV-2 monitoring in indoor environments where transmission risk of the virus is high and the need to avoid individual-level sampling for privacy or compliance reasons exists. ImportanceBecause SARS-CoV-2, the virus that causes COVID-19, persists on surfaces, testing swabs taken from surfaces is useful as a monitoring tool. This approach is especially valuable in school settings, where there are cost and privacy concerns that are eliminated by taking a single sample from a classroom. However, the virus persists for days to weeks on surface samples, so it is impossible to tell whether positive detection events on consecutive days are persistent signal or new infectious cases, and therefore whether the positive individuals have been successfully removed from the classroom. We compare several methods for cleaning "sentinel cards" to show that this approach can be used to identify new SARS-CoV-2 signals day to day. The results are important for determining how to monitor classrooms and other indoor environments for SARS-CoV-2 virus.

bioinformatics↗

bioRxiv2020

The zinc finger protein CLAMP promotes long-range chromatin interactions that mediate dosage compensation of the Drosophila male X-chromosome

Drosophila dosage compensation is an important model system for defining how active chromatin domains are formed. The Male-specific lethal dosage compensation complex (MSLc) increases transcript levels of genes along the length of the single male X-chromosome to equalize with that on the two female X-chromosomes. The strongest binding sites for MSLc cluster together in three-dimensional space independent of MSLc because clustering occurs in both sexes. CLAMP, a non-sex specific, ubiquitous zinc finger protein, binds synergistically with MSLc to enrich the occupancy of both factors on the male X-chromosome. Here, we demonstrate that CLAMP promotes the observed clustering of MSLc bindings sites. Genome-wide, CLAMP promotes interactions between active chromatin regions. Moreover, the X-enriched CLAMP protein more strongly promotes longer-range interactions on the X-chromosome than autosomes. Genome-wide, CLAMP promotes interactions between active chromatin regions together with other insulator proteins. Overall, we define how long-range interactions which are modulated by a locally enriched ubiquitous transcription factor promote hyper-activation of the X-chromosome to mediate dosage compensation.

genomics↗

bioRxiv2020

CLAMP and Zelda function together as pioneer transcription factors to promote Drosophila zygotic genome activation

During the essential and conserved process of zygotic genome activation (ZGA), chromatin accessibility must increase to promote transcription. Drosophila is a well-established model for defining mechanisms that drive ZGA. Zelda (ZLD) is a key pioneer transcription factor (TF) that promotes ZGA in the Drosophila embryo. However, many genomic loci that contain GA-rich motifs become accessible during ZGA independent of ZLD. Therefore, we hypothesized that other early TFs that function with ZLD have not yet been identified, especially those that are capable of binding to GA-rich motifs such as CLAMP. Here, we demonstrate that Drosophila embryonic development requires maternal CLAMP to: 1) activate zygotic transcription; 2) increase chromatin accessibility at promoters of specific genes that often encode other essential TFs; 3) enhance chromatin accessibility to facilitate ZLD occupancy at a subset of key embryonic promoters. Thus, maternal CLAMP functions with ZLD in a pioneer-like role to drive zygotic genome activation.

genomics↗