The impact of obesity, age, and gender on plasmatic levels of selected glycoprotein biomarkers and miRNA-499 in OSA patients.

BACKGROUND: The current obstructive sleep apnea (OSA) diagnostic uses polysomnography or limited polygraphy and requires specialized personnel and technical equipment. Glycoprotein biomarkers and microRNAs are being explored as a possible new method for screening. We aimed to evaluate whether certain biomarkers and microRNA, previously identified as related to OSA, could be influenced by factors such as gender, age, and obesity level in patients with OSA. METHODS: In this retrospective analytical study, patients with moderate to severe OSA (n = 130) were compared with the control group. Serum levels of selected biomarkers and microRNA were taken from both groups. The group of OSA patients was then stratified by gender, obesity level, and age to see the possible influence of those variables on biomarker levels. RESULTS: Levels of all studied biomarkers - C-reactive protein (CRP), high-sensitivity troponin I (hsTnI), pentraxin-3 (PTX-3), and microRNA-499 were significantly higher in patients with OSA compared to the control group. In the OSA group only hsTnI showed a statistically significant relationship with gender. Levels of CRP and hsTnI showed a significant dependence on the level of obesity. Dependency on age was proven for hsTnI. CRP, PTX-3, and microRNA-499 did not have any statistically significant relationship with age. CONCLUSION: We found that serum levels of pentraxin-3 and microRNA-499 in patients with moderate to severe obstructive sleep apnoea are independent of gender, obesity, and age. CRP was affected by the level of obesity and hsTnI was influenced by all 3 variables. We consider these findings important for further research of OSA biomarkers.

Newborn Hearing Screening - An Implementation Analysis.

BACKGROUND/AIM: Hearing impairment affects a small but significant percentage of newborns (0.1-0.4%). Newborn hearing screening (NHS) is recommended for early detection and treatment. The implementation of NHS can vary among countries. In this study, we present the methodology, organization, and technical requirements of NHS. This study analyzed results from a tertiary hospital, identified issues, and proposed solutions. PATIENTS AND METHODS: In the studied region, there are five maternity hospitals and a perinatal intensive care center and in 2020, there were 5,864 live births. Screening is performed at three levels. The first screening is conducted on the 2nd-3rd day of a newborn's life in a maternity hospital, the first rescreening on the 3rd-6th week at a relevant ENT department, and the second rescreening on the 3rd-6th month of life at the regional screening center where the central database is also held. RESULTS: In the studied region, 5,793 out of 5,864 (98.79%) newborns received NHS in 2020. Of these, 120 (2.07%) were tested positive on their first screening. Ninety-four patients (78.3%) of those attended the ENT department for a first rescreening. Thirty-four patients (0.59% of total) were tested positive again and referred to the regional screening center. Out of the 27 patients who attended the second rescreening, four (0.07% of the total) were ultimately diagnosed with hearing impairment. CONCLUSION: Our study found that newborn hearing screening (NHS) in our region achieved a high compliance rate of 98.8% for initial screenings in 2020. However, challenges remain in the rescreening process due to data management issues, inter-regional cooperation, and public awareness. The recent implementation of mandatory screenings, updated guidelines, and a centralized database is expected to enhance the effectiveness of NHS. Further research is needed to evaluate these improvements.

Lipoprotein Subfractions Associated with Endothelial Function in Previously Healthy Subjects with Newly Diagnosed Sleep Apnea-A Pilot Study.

BACKGROUND: Obstructive sleep apnea (OSA) activates several pathophysiological mechanisms which can lead to the development of vascular diseases. Endothelial dysfunction (ED) is an initial step in the development of atherosclerosis. The association between ED and OSA has been described in several studies, even in previously healthy subjects. High-density lipoproteins (HDL) were generally considered to be atheroprotective, and low-density lipoprotein (LDL) to be an atherogenic component of lipoproteins. However, recent findings suggest a pro-atherogenic role of small HDL subfractions (8-10) and LDL subfractions (3-7). This study aimed to evaluate the relationship between endothelial function and lipid subfractions in previously healthy OSA subjects. MATERIAL AND METHODS: We prospectively enrolled 205 subjects with sleep monitoring. Plasma levels of triacylglycerols, total cholesterol, LDL, HDL, and their subfractions were assessed. Endothelial function was determined using peripheral arterial tonometry, and reperfusion hyperemia index (RHI) was assessed. RESULTS: Plasma levels of small and intermediate HDL subfractions have statistically significant pro-atherogenic correlations with endothelial function (p = 0.015 and p = 0.019). In other lipoprotein levels, no other significant correlation was found with RHI. In stepwise multiple linear regression analysis, small HDL (beta = -0.507, p = 0.032) was the only significant contributor in the model predicting RHI. CONCLUSIONS: In our studied sample, a pro-atherogenic role of small HDL subfractions in previously healthy subjects with moderate-to-severe OSA was proven.

Epidemiological and Microbiological Aspects of the Peritonsillar Abscess.

Peritonsillar abscess (PTA) is the most common complication of tonsillitis. Cultivation usually reveals a wide spectrum of aerobic and anaerobic microbiota. This retrospective study compared PTA incidence and the spectrum of individual microbial findings in groups of patients divided by gender, age, and season. Of the 966 samples cultivated, a positive cultivation finding was detected in 606 patients (62.73%). Cultivation findings were negative in 360 (37.27%), meaning no pathogen was present or only common microbiota was cultivated. The highest incidence of PTA was found in group I patients (19-50 years) (p ≤ 0.0001) and the most frequently cultured pathogens was Streptococcus pyogenes (36.23%). Gender seemed to have an influence on the results, with higher incidence found in males (p ≤ 0.0001). The analysis of correlation between PTA incidence and season did not yield statistically significant results (p = 0.4396) and no statistically significant differences were observed in individual pathogen frequency. PTA had a higher incidence in adult males and a slightly higher incidence in girls in childhood. The following findings are clinically significant and have implications for antibiotic treatment strategy: (1) the most frequently cultivated pathogen was Streptococcus pyogenes; (2) an increased incidence of anaerobes was proven in the oldest group (>50 years).

Functional characterization of mutants in the transmembrane domains of the rat P2X7 receptor that regulate pore conductivity and agonist sensitivity.

In the sustained presence of agonist, the opening of P2X7R channel is followed by pore dilatation, which causes an increase in its permeability to larger organic cations, accompanied by receptor sensitization. To explore the molecular mechanisms by which the conductivity and sensitivity are increased, we analyzed the electrophysiological properties and YO-PRO-1 uptake of selected alanine mutants in the first and second transmembrane domains of the rat P2X7R. Substitution of residues Y40, F43, G338, and D352 with alanine reduced membrane trafficking, and the D352A was practically non-functional. The Y40A and F43A mutants that were expressed in the membrane lacked pore dilation ability. Moreover, the Y40A and Y40F displayed desensitization, whereas the Y40W partially recovered receptor function. The G338A/S mutations favored the open state of the channel and displayed instantaneous permeability to larger organic cations. The G338P was non-functional. The L341A and G345A displayed normal trafficking, current amplitude, and sensitization, but both mutations resulted in a decreased pore formation and dye uptake. These results showed that the increase in P2X7R conductivity and sensitivity is critically dependent on residues Y40 and F43 in the TM1 domain and that the region located at the intersection of TM2 helices controls the rate of large pore opening. We investigated the mechanism of the proapoptotic receptor P2X7R's large pore opening and its sensitization. We found that aromatic residues in the upper part of the first transmembrane domain (TM1) are critical for both the P2X7R channel pore opening and receptor sensitization, and residues located at or below the intersection of the second transmembrane domains (TM2) control the rate of pore opening. These findings identify new residues involved in pore formation of P2X7R.

Effects of acute stressors on the expression of oxytocin receptor mRNA in hearts of rats with different activity of HPA axis.

OBJECTIVES: Cardiovascular system is regulated by a diverse array of hormones, neurotransmitters and neuropeptides. Oxytocin and its receptors (OTR) were also shown to regulate cardiovascular functions and this hormone was even called cardiovascular hormone. In recent publication, we demonstrated the expression of mRNA of OTR by real-time quantitative PCR (RT qPCR) in all rat heart compartments. The aim of this study was to investigate the effects of acute restraint stress on OTR mRNA expression in two rat strains with different activity of HPA axis. METHODS: Adult male Sprague-Dawley and Lewis rats, the latter strain reported to have lower HPA activity, were used in RT qPCR studies and Wistar rats in immunofluorescent ones. Both acute restraint (IS) and this stress combined with the immersion of rats in water (ICS) lasted 60 min. Gene expression of OTR mRNA was estimated in all heart compartments after 1 or 3 hours after stress termination (IS1, IS3, ICS1, ICS3). The relative expression was calculated using 2(-ΔΔC)T method. In immunofluorescent studies we used commercial specific OTR antibodies. RESULTS: In RT qPCR studies we found higher expression of OTR mRNA in atria than in ventricles and no statistical differences between Sprague-Dawley and Lewis rats under basal conditions. Relative expression of OTR mRNA after 60 min lasting stress exposure differed in dependence on the stress type and partly on the time interval after the stress termination. When compared to controls, in rat left atria both stressors caused inhibition of OTR mRNA expression in both rat strains. In rat ventricles, which have very low OTR mRNA expression, there was a significant difference in the effect of two stressors. In most groups ICS displayed the increase of OTR mRNA expression if compared to IS groups. Immunofluorescent studies revealed changes induced by acute restraint stress in all heart compartments. The immunofluorescent studies suggested that acute stress induces higher colocalization of OTR with the nuclei than it was observed in the controls. CONCLUSIONS: The expression of OTR mRNA in all heart compartments of controls as well as after stress exposure in Sprague-Dawley and Lewis rats support the notion that OTR plays a regulatory role in the cardiovascular system and is also involved in the regulations in the heart after stress. The immunofluorescent observation that OTRs coexpress in areas of cell nuclei in certain heart compartments and after acute stress, compared to controls, requires further studies.

Galanin modulating effect on restraint stress-induced short- and long-term behavioral changes in Wistar rats.

The neuropeptide galanin has been recognized as a possible neurotransmitter/neuromodulator, and in addition has been implicated in anxiety- and depression-related behaviors. The present study demonstrates increased locomotion and rearing after galanin (0.3mg/kg) that was given intraperitoneally (i.p.) to intact Wistar rats which were tested 1h later in the open field (OF). These effects, which suggest an anxiolytic-like action, were blocked by i.p. administered peptidic galanin antagonist M40. Further, the locomotion increase caused by galanin and the inhibitory effect of M40 persisted for 48h without additional treatment. Rats exposed to restraint stress (lasting 60min) for three consecutive days and tested 1h after stress termination exhibited reduced locomotion and exploration in the OF. Galanin (0.3 and 1.0mg/kg) given immediately after each stress exposure prevented the decrease of locomotion and exploration induced by stress in all trials. When the test was repeated 6 days later without stress and galanin treatment the reduction of locomotion produced by stress persisted; the anti-stress behavioral effects of both galanin doses were also present. Testing performed on the 12th day after the last stress and galanin treatment with 0.3mg/kg revealed an increased locomotion compared with unstressed and stress-exposed rats. Our results demonstrate that behavioral effects of the peptide galanin are evident even after i.p. administration. These results also suggest that galanin elicits stress-modulatory action, and support the notion that the galaninergic system may serve as a drug target in stress-related conditions.

Expression of heart oxytocin receptor and its mRNA in two rat strains with different activity of HPA axis.

OBJECTIVES: Oxytocin (OT) is a neuropeptide acting both as a peripheral hormone and in the brain as neurotransmitter and neuromodulator. In addition to its well-known effects on milk-ejection and uterine contraction, OT was shown to exert neuroendocrine regulation of heart functions. The aim of this study was to investigate the expression of mRNA of OT receptors (OTR) in rat hearts by real-time quantitative PCR (qPCR). The study was performed in Sprague-Dawley (SD) and Lewis (LE) rat strains, the latter having lower activity of HPA axis. METHODS: We used adult male SD and LE rats. OTR mRNA expression was detected in all heart chambers by comparing their threshold cycle values (CT) to CT of reference gene ß-actin. The relative expression ratios were calculated using the 2-ΔΔCT method. The specificity of reaction of primary antibody with OTRs was tested by Western Blot and localization of OTR in the heart compartments was performed by immunofluorescence with commercial OTR specific antibodies. RESULTS: We found expression of OTR mRNA in all heart compartments. The expression of OTR mRNA in both atria (LA, RA) was much higher than in the ventricles (RV, LV). By using two-way ANOVA we found no statistical differences between corresponding compartments of SD and LE rats. Immunohistochemical studies showed that OTR staining is not related to neuronal tissue and findings from left atrium indicate that prevalent localization of OTR is on cell membranes of cardiomyocytes. CONCLUSIONS: The finding of expression of OTR mRNA by real-time qPCR and proof of OTR staining by immunohistochemistry in all heart compartments indicate that OT and its receptors may have function as a cardiovascular hormone. The differences in the HPA axis activity, as is exemplified in Sprague-Dawley and Lewis rat strain, do not project in the expression of OTR mRNA under basal condition. The effect of activity of HPA on OTR expression should be studied under stimulated conditions as it was performed in the behavioral studies.