Stefan Lassan

Dr. Stefan Lassan

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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14 December 2024 in Diseases
Verified
Journal Article
Open access
PDF file
MSMilan Smiesko
Milan Smiesko
EJEster Jenigarova
Ester Jenigarova
PSPeter Stanko
Peter Stanko
ZKZsolt Kasa
Zsolt Kasa
IČIvan Čavarga
Ivan Čavarga
SLStefan Lassan
Stefan Lassan
Obstructive sleep apnea syndrome (OSAS) is a frequently underdiagnosed sleep disorder marked by recurrent episodes of apnea and/or hypopnea during sleep, primarily resulting from the partial or complete collapse of the upper airway. OSAS significantly affects patients’ health and quality of life. Additionally, it is a recognized risk factor for inducing microsleep episodes during daily activities, particularly in occupations such as professional driving, where sustained attention is critical. The aim of our study was to identify an effective screening test for use in outpatient settings, capable of distinguishing patients with a severe form of OSAS. Patients who test positive with this screening tool would subsequently be prioritized for polysomnographic evaluation in a sleep laboratory. A total of 64 patients who underwent polysomnography (PSG) or polygraphy (PG) examination at our clinic were subsequently examined by USG of the tongue with measurements of tongue base thickness (TBT) and the distance between lingual arteries (DLA) during wakefulness and in a relaxed tongue position. The measurements of TBT and DLA were subsequently correlated with the apnea–hypopnea index (AHI) obtained from PSG or PG. In our cohort of patients diagnosed with severe OSAS, a TBT threshold of ≥65 mm served as an effective cutoff value. A TBT value of ≥65 mm reached an AUC value of 78.1%, sensitivity of 74.4%, specificity of 61.9%, positive predictive value of 80%, negative predictive value of 54.2% and overall accuracy of 70.3%. A DLA value of ≥30 mm in our sample of patients with severe OSAS showed an AUC of 76.5%, sensitivity of 69.8%, specificity of 71.1%, positive predictive value of 83.3%, negative predictive value of 53.6%, and overall accuracy of 70.3%. Tongue USG markers, particularly TBT and DLA measurements during wakefulness and in a relaxed tongue position, show potential as effective screening tools for identifying severe OSAS in European populations. These markers demonstrate improved accuracy over traditional screening questionnaires by reducing the likelihood of false-negative results. Patients with a positive screening should preferably be referred for polysomnography. In this way, patients with a serious illness could receive adequate therapy sooner.

14 July 2023 in Microorganisms
Verified
Journal Article
Open access
PDF file
MHMichaela Hyblova
Michaela Hyblova
DHDominik Hadzega
Dominik Hadzega
KBKlaudia Babisova
Klaudia Babisova
PKPatrik Krumpolec
Patrik Krumpolec
AGAndrej Gnip
Andrej Gnip
GMGabriel Minarik
Gabriel Minarik
The recent global emergence of the SARS-CoV-2 pandemic has accelerated research in several areas of science whose valuable outputs and findings can help to address future health challenges in the event of emerging infectious agents. We conducted a comprehensive shotgun analysis targeting multiple aspects to compare differences in bacterial spectrum and viral presence through culture-independent RNA sequencing. We conducted a comparative analysis of the microbiome between healthy individuals and those with varying degrees of COVID-19 severity, including a total of 151 participants. Our findings revealed a noteworthy increase in microbial species diversity among patients with COVID-19, irrespective of disease severity. Specifically, our analysis revealed a significant difference in the abundance of bacterial phyla between healthy individuals and those infected with COVID-19. We found that Actinobacteria, among other bacterial phyla, showed a notably higher abundance in healthy individuals compared to infected individuals. Conversely, Bacteroides showed a lower abundance in the latter group. Infected people, regardless of severity and symptoms, have the same proportional representation of Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Fusobacteriales. In addition to SARS-CoV-2 and numerous phage groups, we identified sequences of clinically significant viruses such as Human Herpes Virus 1, Human Mastadenovirus D, and Rhinovirus A in several samples. Analyses were performed retrospectively, therefore, in the case of SARS-CoV-2 various WHO variants such as Alpha (B.1.1.7), Delta (B.1.617.2), Omicron (B.1.1.529), and 20C strains are represented. Additionally, the presence of specific virus strains has a certain effect on the distribution of individual microbial taxa.

7 June 2023 in Preprints.org
Verified
Preprint
Open access
PDF file
MHMichaela Hyblova
Michaela Hyblova
DHDominik Hadzega
Dominik Hadzega
KBKlaudia Babisova
Klaudia Babisova
PKPatrik Krumpolec
Patrik Krumpolec
AGAndrej Gnip
Andrej Gnip
GMGabriel Minarik
Gabriel Minarik
The recent global emergence of the SARS-CoV-2 pandemic has accelerated research in several areas of science whose valuable outputs and findings can help to address future health challenges in the event of emerging infectious agents. We performed a multifocus shotgun analysis to compare differences in bacterial spectrum and viral presence through culture-independent RNA sequencing. We compared the microbiome of healthy people versus those with varying degrees of COVID-19 severity. We observed a significant increase in the diversity of microbial species in patients with COVID-19 regardless of disease severity. Some bacterial phyla, such as Actinobacteria, are significantly more abundant in healthy people than in infected people, whereas Bacteroides are less abundant in the latter. Infected people, regardless of severity and symptoms, have the same proportional representation of Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Fusobacteriales the same. In addition to SARS-CoV-2 and numerous phage groups, we identified sequences of clinically significant viruses such as Human Herpes Virus 1, Human Mastadenovirus D, Molluscum Contagiosum Virus, and Rhinovirus A in several samples. Analyses were performed retrospectively, therefore, in the case of SARS-CoV-2 various WHO variants such as Alpha (B.1.1.7), Delta (B.1.617.2), Omicron (B.1.1.529), and 20C strains are represented. Additionally, the presence of specific virus strains has a certain effect on the distribution of individual microbial taxa.