Biology subjects

Rowe, S.

Publications and source records attributed to Rowe, S..

3 recordsLinked to original sources

bioRxiv2021

Poly (acetyl arginyl) glucosamine attenuates Pseudomonas aeruginosa in a rat lung infection model

Pseudomonas aeruginosa is a common opportunistic pathogen that can cause chronic infections in multiple disease states, including respiratory infections in patients with cystic fibrosis (CF) and non-CF bronchiectasis. Like many opportunists, P. aeruginosa forms multicellular biofilm communities that are widely thought to be an important determinant of bacterial persistence and resistance to antimicrobials and host immune effectors during chronic/recurrent infections. Poly (acetyl, arginyl) glucosamine (PAAG) is a glycopolymer which has antimicrobial activity against a broad range of bacterial species, and also has mucolytic activity which can normalize rheologic properties of cystic fibrosis mucus. In this study, we sought to evaluate the effect of PAAG on P. aeruginosa bacteria within biofilms in vitro, and in the context of experimental pulmonary infection in a rodent infection model. PAAG treatment caused significant bactericidal activity against P. aeruginosa biofilms, and a reduction in the total biomass of preformed P. aeruginosa biofilms on abiotic surfaces, as well as on the surface of immortalized cystic fibrosis human bronchial epithelial cells. Studies of membrane integrity indicated that PAAG causes changes to P. aeruginosa cell morphology and dysregulates membrane polarity. PAAG treatment reduced infection and consequent tissue inflammation in experimental P. aeruginosa rat infections. Based on these findings we conclude that PAAG represents a novel means to combat P. aeruginosa infection, which may warrant further evaluation as a therapeutic.

microbiology↗

bioRxiv2021

Odorization of Natural Gas: What are the Challenges?

Modern natural gas (NG) has little or no odor, so other compounds, usually mercaptans and thiols, are added as warning odorants. Federal regulations state that NG must be odorized so that it is readily detectable by people with normal senses of smell at one fifth the lower explosive limit, but regulations dont define "readily detectable" or "normal senses of smell." Methods to measure human odor detection have been available for decades. However, most previous work on NG odorants has underestimated human sensitivity, and measurements need to be repeated using the latest methods. More work is also needed to determine how odor sensitivity measured under optimal laboratory conditions is affected by real-world factors such as distraction and exposure to other odors in the environment. Regarding a "normal sense of smell," healthy people vary over orders of magnitude in the concentrations they can detect, so samples of subjects should be chosen to reflect the range of differences in the population.

physiology↗

bioRxiv2019

The transcription factor Shox2 shapes thalamocortical neuron firing properties by regulation of key ion channels

Thalamocortical neurons (TCNs) transmit information about sensory stimuli from the thalamus to the cortex. In response to different physiological states and demands TCNs can fire in tonic and/or phasic burst modes. These firing properties of TCNs are supported by precisely timed inhibitory synaptic inputs from the thalamic reticular nucleus and intrinsic currents, including T-type Ca2+ and HCN currents. These intrinsic currents are mediated by Cav3.1 and HCN channel subunits, and alterations in expression or modulation of these channels can have dramatic implications on thalamus function. The factors that regulate these currents controlling the firing patterns important for integration of the sensory stimuli and the consequences resulting from the disruption of these firing patterns are not well understood. Shox2 is a transcription factor known to be important for pacemaker activity in the heart. We show here that Shox2 is also expressed in adult mouse thalamus. We hypothesized that genes regulated by Shox2s transcriptional activity may be important for physiological properties of TCNs. In this study, we used RNA sequencing on control and Shox2 knockout mice to determine Shox2-affected genes and revealed a network of ion channel genes important for neuronal firing properties. Quantitative PCR confirmed that expression of Hcn2, 4 and Cav3.1 genes were affected by Shox2 KO. Western blotting showed expression of the proteins for these channels was decreased in the thalamus, and electrophysiological recordings showed that Shox2 KO impacted the firing and synaptic properties of TCNs. Finally, behavioral studies revealed that Shox2 expression in TCNs play a role in somatosensory function and object recognition memory. Overall, these results reveal Shox2 as a transcription factor important for TCN firing properties and thalamic function.

neuroscience↗