The Role of Ovalbumin in Manganese Homeostasis during Chick Embryogenesis: An EPR Spectroscopic Study.

Ovalbumin (OVA), a protein vital for chick embryo nutrition, hydration, and antimicrobial protection, together with other egg-white proteins, migrates to the amniotic fluid and is orally absorbed by the embryo during embryogenesis. Recently, it has been shown that for optimal eggshell quality, the hen diet can be supplemented with manganese. Although essential for embryonic development, manganese in excess causes neurotoxicity. This study investigates whether OVA may be involved in the regulation of manganese levels. The binding of Mn(II) to OVA was investigated using electron paramagnetic resonance (EPR) spectroscopy. The results show that OVA binds a maximum of two Mn(II) ions, one with slightly weaker affinity, even in a 10-fold excess, suggesting it may have a protective role from Mn(II) overload. It seems that the binding of Mn(II), or the presence of excess Mn(II), does not affect OVA's tertiary structure, as evidenced from fluorescence and UV/vis measurements. Comparative analysis with bovine and human serum albumins revealed that they exhibit higher affinities for Mn(II) than OVA, most likely due to their essentially different physiological roles. These findings suggest that OVA does not play a role in the transport and storage of manganese; however, it may be involved in embryo protection from manganese-induced toxicity.

Physical Activity as a Means to Improve Subjective Vitality of University Students.

Purpose: This study compared physical self-concept and subjective vitality of police, physical education, and psychology students. Moreover, the study investigated whether students who reported a higher level of physical activity differently rated physical self-concept and subjective vitality and whether physical activity was associated with subjective vitality. Methods: The study sample included 422 university students (249 females) from three state academic institutions: University of Criminal Investigation and Police Studies (n = 165), Faculty of Sport and Physical Education (n = 156) and Faculty of Psychology (n = 101). The mean age was 20.85 ± 3.59 years. They completed a physical self-description questionnaire, the subjective vitality scale, and a physical activity questionnaire using the Survey Monkey platform. Multivariate analysis of variance investigated the differences in physical activity, physical self and vitality, while regression analysis investigated the association of physical self and physical activity with subjective vitality. Results: Police students and physical education students reported higher levels of physical activity and perceived higher their own physical self and subjective vitality than psychology students. From the whole sample, students who were sufficiently physically active also scored higher on physical self-concept and subjective vitality. There was a significant association of physical activity level with subjective vitality. Conclusion: Physical activity was directly associated with students' subjective evaluation of their own health. It can be concluded that students should aim to attain a minimum of 150 min per week of physical activity. Students and faculties should be involved in the attainment of minimal levels of physical activity. This could improve students' subjective perception of self, along with objective measures of health and wellbeing.

The Release of a Highly Cytotoxic Paullone Bearing a TEMPO Free Radical from the HSA Hydrogel: An EPR Spectroscopic Characterization.

This study shows the potential of a thermally induced human serum albumin (HSA) hydrogel to serve as a drug depot for sustained release of a highly cytotoxic modified paullone ligand bearing a TEMPO free radical (HL). The binding of HL to HSA was studied by electron paramagnetic resonance (EPR) spectroscopy and imaging. The EPR protocol was also implemented for the study of matrix degradation, and ligand diffusion rate, in two additional spin-labeled hydrogels, containing 5-doxylstearate and 3-carbamoyl-proxyl. The results showed that the hydrogel is an efficient HL reservoir as it retained 60% of the ligand during 11 days of dialysis in physiological saline. Furthermore, upon incubation with Colo 205 human colon adenocarcinoma cells for 3 days, the HL/HSA hydrogel did not exhibit cytotoxic activity, demonstrating that it is also an efficient ligand depot in the presence of living cells. It was observed that the percentage of HL release is independent of its initial concentration in the hydrogel, suggesting that HSA possesses a specific binding site for the ligand, most likely Sudlow site 2, as predicted by molecular docking. The intrinsic property of albumin to bind and transport various substances, including hydrophobic drugs, may be fine-tuned by appropriate physical/chemical hydrogel preparation procedures, providing optimal drug delivery.

Association between perceived stress, coping profile and fear during the COVID-19 pandemic among male and female police students.

BACKGROUND: Coronavirus (COVID-19) outbreak was a sudden unknown stressor that could cause fear among people. Police officers were in the front lines, often unknowingly in direct contact with infected individuals, thus fear of getting infected (i.e., fear of COVID-19) could be higher in this population. Police students are preparing for the job of police officers and how they cope with a sudden unknown situation could be of importance for job performance and their mental health if such a situation occurs. This study aimed to investigate the association of perceived stress and coping strategies with fear of COVID-19 in police students. MATERIAL AND METHODS: Perceived stress scale-10, Brief COPE, and Fear of COVID-19 (FSV-19) were administered to 340 police students (female = 183 [53.82%] and male = 157 [46.18%]). Correlation analysis was applied to test the association between perceived stress, all dimension of coping and fear of COVID-19. Multivariate analysis of variance was used to investigate between-gender differences. For mediating and moderating effect of coping primary coping style were used. RESULTS: MANOVA reviled that significant differences occurred in perceived stress, 3 primary coping styles and fear of COVID-19 based on a gender. Stepwise regression analysis extracted the most significant predictors of fear of COVID-19. Perceived stress was the strongest predictor in general and in both genders. Denial and self-distancing were significant coping subscales in males, while humour and denial were significant in females. CONCLUSIONS: Perceived stress and coping strategies that students used to deal with the situation moderately defined their fear of COVID-19 outbreak, with perceived stress being the strongest predictor. Med Pr. 2022;73(3):179-90.

Spectroscopic Characterization of the Binding and Release of Hydrophilic, Hydrophobic and Amphiphilic Molecules from Ovalbumin Supramolecular Hydrogels.

Protein-based hydrogels have attracted growing attention for pharmaceutical and biomedical applications. Ovalbumin (OVA), the hen egg white albumin, possessing good foaming and gelling properties and being widely used in the food industry, has recently been indicated as a potential pharmaceutical vehicle. In this study, the binding and release properties of pure OVA hydrogels were investigated by electron paramagnetic resonance (EPR) spin labeling. The comparative analysis between OVA and serum albumin (SA) hydrogels revealed the same release kinetics of hydrophilic 3-carbamoyl-proxyl and 3-carboxy-proxyl, suggesting the diffusion-dominated release of small probes from both hydrogel types. The results obtained with the amphiphilic 16-doxylstearate (16-DS) indicate that OVA, unlike SAs, does not possess a specific fatty acid binding site. However, the OVA hydrogels were able to accommodate a two-fold excess of 16-DS, resulting from protein thermally induced conformational changes, as confirmed by Raman spectroscopy. Similarly, the hydrophobic modified paullone ligand HL, which was initially free in the OVA solution, was bound in the hydrogel. The hydrogels were found to retain a significant amount of 16-DS and HL after 7-day dialysis in physiological saline. The observed facilitated binding of amphiphilic/hydrophobic molecules in OVA hydrogels compared to the solution, and their sustained release, demonstrate the applicability of OVA hydrogels in pharmaceutics.

In Vivo/Ex Vivo EPR Investigation of the Brain Redox Status and Blood-Brain Barrier Integrity in the 5xFAD Mouse Model of Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) is the most common neurodegenerative disorder characterized by cognitive decline and total brain atrophy. Despite the substantial scientific effort, the pathological mechanisms underlying neurodegeneration in AD are currently unknown. In most studies, amyloid ß peptide has been considered the key pathological change in AD. However, numerous Aß-targeting treatments have failed in clinical trials. This implies the need to shift the research focus from Aß to other pathological features of the disease. OBJECTIVE: The aim of this study was to examine the interplay between mitochondrial dysfunction, oxidative stress and blood-brain barrier (BBB) disruption in AD pathology, using a novel approach that involves the application of electron paramagnetic resonance (EPR) spectroscopy. METHODS: In vivo and ex vivo EPR spectroscopy using two spin probes (aminoxyl radicals) exhibiting different cell-membrane and BBB permeability were employed to assess BBB integrity and brain tissue redox status in the 5xFAD mouse model of AD. In vivo spin probe reduction decay was analyzed using a two-compartment pharmacokinetic model. Furthermore, 15 K EPR spectroscopy was employed to investigate the brain metal content. RESULTS: This study has revealed an altered brain redox state, BBB breakdown, as well as ROS-mediated damage to mitochondrial iron-sulfur clusters, and up-regulation of MnSOD in the 5xFAD model. CONCLUSION: The EPR spin probes were shown to be excellent in vivo reporters of the 5xFAD neuronal tissue redox state, as well as the BBB integrity, indicating the importance of in vivo EPR spectroscopy application in preclinical studies of neurodegenerative diseases.

Perceived and Measured Physical Fitness of Police Students.

The physical fitness of police officers needs to support good health and physical performance. Physical fitness comprises a considerable amount of training for police students who are to become police officers. However, to what degree police students are able to perceive their fitness level and differentiate between health-related and performance-related physical fitness is unknown. Therefore, the first aim of this study was to investigate the possibility of differentiation between health-related and performance-related physical fitness using physical self-concept and measured indicators of physical fitness. The second aim of this study was to investigate the association between components of physical self-concept and measured indicators of physical fitness of police students. The sample of 177 police students of both sexes (98 males and 79 females) completed a 40-item physical self-description questionnaire and their physical abilities were assessed for handgrip strength, standing long jump, 30 s sit-ups, and 12-min running. Principal component analysis established health-related and performance-related physical fitness from both perceived and measured physical fitness measures. Correlation analysis revealed a significant relationship between the perceived and measured physical fitness. Results suggest small to moderate ability to recognize the level of certain physical abilities, indicating the association between psychological mechanisms and biological functioning.

Nutritional and physical activity behaviours and habits in adolescent population of Belgrade.

BACKGROUND/AIM: Proper nutrition and regular physical activity are essential parts of a adolescent's overall health. The aim of this research was to evaluated eating and physical activity behaviours and habits, nutritional and food knowledge, beliefs and self-efficacy related to diet and health of the adolescents of the city of Belgrade, Serbia. METHODS: A dietary questionnaire previously constructed and tested in adolescent population from Italy was self-administrated. We evaluated eating habits, physical activity, meaning of healthy and unhealthy dietary habits and food, self-efficacy, barriers affecting food choices, nutritional and food safety, and body mass index (BMI) of the adolescents. The sample included 707 adolescents, the mean age of 15,8 +/- 2 years enrolled in the first grade at several high schools in Belgrade. RESULTS: Only 27% of the adolescents had satisfactory eating habits; 31% have a very active lifestyle; 7% good nutritional knowledge and 6-12% satisfactory food safety knowledge and hygiene practices. CONCLUSION: Significant deviations from recommendations for healthy lifestyle was noted in adolescents' habits, knowledge and practice. It is therefore necessary to develop and organize programs for promotion of healthy behaviours adapted to the adolescents' needs.