George Katselis

George Katselis

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 April 2021 in Scientific Reports
Verified
Journal Article
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MNManoj Nair
Manoj Nair
SJSantosh Jagadeeshan
Santosh Jagadeeshan
GKGeorge Katselis
George Katselis
XLXiaojie Luan
Xiaojie Luan
ZMZeinab Momeni
Zeinab Momeni
VCVerónica A. Campanucci
Verónica A. Campanucci
Thoracic dorsal root ganglia (tDRG) contribute to fluid secretion in the upper airways. Inflammation potentiates DRG responses, but the mechanisms remain under investigation. The receptor for advanced glycation end-products (RAGE) underlies potentiation of DRG responses in pain pathologies; however, its role in other sensory modalities is less understood. We hypothesize that RAGE contributes to electrophysiological and biochemical changes in tDRGs during inflammation. We used tDRGs and tracheas from wild types (WT), RAGE knock-out (RAGE-KO), and with the RAGE antagonist FPS-ZM1, and exposed them to lipopolysaccharides (LPS). We studied: capsaicin (CAP)-evoked currents and action potentials (AP), tracheal submucosal gland secretion, RAGE expression and downstream pathways. In WT neurons, LPS increased CAP-evoked currents and AP generation, and it caused submucosal gland hypersecretion in tracheas from WT mice exposed to LPS. In contrast, LPS had no effect on tDRG excitability or gland secretion in RAGE-KO mice or mice treated with FPS-ZM1. LPS upregulated full-length RAGE (encoded by Tv1-RAGE) and downregulated a soluble (sRAGE) splice variant (encoded byMmusRAGEv4) in tDRG neurons. These data suggest that sensitization of tDRG neurons contributes to hypersecretion in the upper airways during inflammation. And at least two RAGE variants may be involved in these effects of LPS.

23 July 2019 in Journal of Antimicrobial Chemotherapy
Verified
Journal Article
Closed access
Reema SinghReema Singh
Reema Singh
SPSumudu Perera
Sumudu Perera
GKGeorge Katselis
George Katselis
PCPaulos Chumala
Paulos Chumala
IMIrene Martin
Irene Martin
JDJo-Anne R. Dillon
Jo-Anne R. Dillon
Background: Seven structurally related β-lactamase-producing plasmids have been characterized in penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates. We characterized a variant (i.e. pJRD20, Canada type) of the Africa-type (pJD5) plasmid isolated from N. gonorrhoeae strain 8903.Objectives: To compare the DNA sequence of pJRD20 with that of pJD5 and pJD4 (Asia-type) and their TEM-1 β-lactamases.Methods: N. gonorrhoeae 8903 was identified as part of the Gonococcal Antimicrobial Surveillance Program in Canada. β-Lactamase production was assessed using nitrocefin. MICs were determined by agar dilution and Etest methods (CLSI). The DNA sequences of pJRD20, pJD5 and pJD4 were assembled and annotated. The structure of TEM-1 and its penicillin-binding properties were determined by in silico molecular modelling and docking. TEM-1 proteins were characterized by western blot, mass spectrometry and ampicillin hydrolysis assays.Results: N. gonorrhoeae 8903 exhibited intermediate susceptibility to penicillin with slow β-lactamase activity (i.e. 35 min to hydrolyse nitrocefin). Except for a novel 6 bp deletion starting at the G of the ATG start codon of blaTEM-1, the DNA sequence of pJRD20 was identical to that of pJD5. The TEM-1 β-lactamase produced by pJRD20 is 24 kDa and hydrolyses ampicillin only after several hours.Conclusions: This unusual PPNG isolate might have been characterized as a non-PPNG owing to its low MIC of penicillin and its very slow hydrolysis of nitrocefin. Given the unusual nature of its TEM-1 β-lactamase, laboratories might consider extending the duration of nitrocefin hydrolysis assays.

1 September 2021 in Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids
Verified
Journal Article
Closed access
PMPamela J. McFie
Pamela J. McFie
PCPaulos Chumala
Paulos Chumala
GKGeorge Katselis
George Katselis
SSScot J. Stone
Scot J. Stone

29 June 2024 in Nutrients
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Journal Article
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ZGZohre Gheisary
Zohre Gheisary
IHIbrahim Hoja
Ibrahim Hoja
JLJuxin Liu
Juxin Liu
PPPétros Papagerakis
Pétros Papagerakis
LWLynn P Weber
Lynn P Weber
SPSilvana Papagerakis
Silvana Papagerakis
Arthritis is associated with health challenges. Lifestyle traits are believed to influence arthritis development and progression; however, data to support personalized treatment regimens based on holistic lifestyle factors are missing. This study aims to provide a comprehensive list of associations between lifestyle traits and the health status of individuals with arthritis in the Canadian population, using binary logistic regression analysis on data from the Canadian Community Health Survey, which includes 104,359 respondents. Firstly, we explored the association between arthritis and various aspects of health status including self-reported lifestyle factors. Secondly, we examined the associations between self-reported dietary intake and smoking status with general, mental, and oral health, and sleep disturbance among individuals both with and without arthritis. Our analysis revealed that individuals with arthritis reported considerably poorer general, mental, and oral health, and poorer sleep quality compared to those without arthritis. Associations were also found between self-reported dietary intake and various measures of health status in individuals with arthritis. Smoking and exposure to passive smoking were associated not only with arthritis but also with compromised sleep quality and poorer general, mental, and oral health in people with and without arthritis. This study highlights the need for personalized and holistic approaches that may include a combination of dietary interventions, oral health improvements, sleep therapies, and smoking cessation for improved arthritis prevention and care.

26 March 2022 in Journal of Proteomics
Verified
Journal Article
Closed access
RKRoman V. Koziy
Roman V. Koziy
JBJose L. Bracamonte
Jose L. Bracamonte
SYSeiji Yoshimura
Seiji Yoshimura
PCPaulos Chumala
Paulos Chumala
ESElemir Simko
Elemir Simko
GKGeorge Katselis
George Katselis

21 January 2024 in Journal of Dentistry
Verified
Journal Article
Closed access
PAParas Ahmad
Paras Ahmad
LMLina Marin
Lina Marin
CLCandace Lowe
Candace Lowe
GKGeorge Katselis
George Katselis
WSWalter Siqueira
Walter Siqueira