Speech is a way of communication formed by rhythmic units of syllables, words and sentences, and as such is inherent in man, the only being whose organs and psyche are trained for this process. Delayed speech is defined as a phenomenon in which a child does not start speaking on time, or there are errors in the speech pattern that are not appropriate in relation to a given age. It is known that significant risk factors for the development of delayed speech in preschool children are physical, and most often social and emotional in nature. For the normal development of speech, it is necessary that the child is in a human environment, and therefore the circle of people with whom children come into contact should always be expanded. The aim of this study is to review the existing literature on studies examining the impact of social isolation during the COVID-19 pandemic on preschool children, as well as the speech and language development in preschool children. The recent pandemic of corona virus infection (COVID-19) has led to a state of emergency, quarantine, closure of public institutions, and preschools, kindergartens and schools in 172 countries. These epidemiological measures have led to social isolation and the need for children to learn from home, which has manifested itself in the emergence of difficulties in the development of speech and language. Research has shown that during the pandemic, children spent significantly more time watching television and computer screens than before pandemic, and less in play and physical activity.

Introduction. Cardiac magnetic resonance imaging (CMR) is considered the reference diagnostic method for quantifying right ventricular size and function, and pulmonary regurgitation in patients with tetralogy of Fallot surgery. The aim of this paper is to confirm the importance of magnetic resonance continuous postoperative monitoring of right and left heart function parameters as a diagnostic method that provides the most precise and accurate assessment. Methods. The prospective observational study included subjects with TOF surgery who were diagnosed with residual morphological and/or functional disorders on control postoperative echocardiographic examinations. All subjects underwent magnetic resonance imaging of the heart on a 1.5 T scanner with dedicated coils for the heart surface according to the standard protocol for a period of one year from the beginning of the study. Criteria for exclusion from the study were: significant residual pulmonary stenosis, condition after pulmonary valve replacement, existence of residual shunt lesions, contraindications for cardiac magnetic resonance imaging (pacemaker, ICD, claustrophobia). Depending on the time elapsed since the tetralogy of Fallot surgery, the subjects were divided into groups: more than 15 years, 11-15 years, 6-10 years, less than 5 years. Results. The study included 131 subjects with an average age of 24.18 ± 11.57 years with complete correction of TOF. Intergroup differences in values of right ventricular end-diastolic volume, right ventricular ejection fraction, and left ventricular ejection fraction were demonstrated, but there was no statistically significant intergroup difference in values of pulmonary regurgitation fraction. The negative interaction of the right and left ventricles intensifies during the years of follow-up of patients after TOF surgery, which is especially true fifteen years after surgery. Conclusion. CMR has the most significant role in research efforts aimed at improving the outcomes of operated patients with tetralogy of Fallot.

This study aimed to generate a linguistic equivalent of the COVID Stress Scales (CSS) in the Serbian language and examine its psychometric characteristics. Data were collected from September to December 2020 among the general population of three cities in Republic of Serbia and Republic of Srpska, countries where the Serbian language is spoken. Participants completed a socio-demographic questionnaire, followed by the CSS and Perceived Stress Scale (PSS). The CSS was validated using the standard methodology (i.e., forward and backward translations, pilot testing). The reliability of the Serbian CSS was assessed using Cronbach’s alpha and McDonald’s omega coefficients and convergent validity was evaluated by correlating the CSS with PSS. Confirmatory factor analysis was performed to examine the construct validity of the Serbian CSS. This study included 961 persons (52.8% males and 47.2% females). The Cronbach’s alpha coefficient of the Serbian CSS was 0.964 and McDonald’s omega was 0.964. The Serbian CSS with 36 items and a six-factorial structure showed a measurement model with a satisfactory fit for our population (CMIN/DF = 4.391; GFI = 0.991; RMSEA = 0.025). The CSS total and all domain scores significantly positively correlated with PSS total score. The Serbian version of the CSS is a valid and reliable questionnaire that can be used in assessing COVID-19-related distress experienced by Serbian speaking people during the COVID-19 pandemic as well as future epidemics and pandemics.

Introduction. Tinnitus is a perception of a sound in the ears in the absence of acoustic stimulation whose pathophysiological mechanisms have not been evaluated yet. Approximately, 1-2% of people report distress which can negatively affect their daily performance. Our study aimed to assess the incidence of anxiety in patients with tinnitus. Methods. The study was designed as a cross-sectional study. The participants were divided into two groups: a group of 73 patients with tinnitus (with two subgroups in relation to the duration of tinnitus-less than one year and more than one year) and a control group of 43 patients without tinnitus. We examined the presence of anxiety in all patients using the Burns Anxiety Inventory (BAI). The quality of life of all patients was estimated by Tinnitus Handicap Inventory (THI). Results. In the group of patients with tinnitus, 56.2% of them had mild and 24.7% moderate hearing loss, while 27.7% of respondents from control group had mild and 8.5% moderate levels of hearing impairment. THI results showed that patients with tinnitus less than 1 year had a significantly (p= 0.002) higher level of disorders in daily life, compared with the group who had tinnitus for more than 1 year. The 30.8% of respondents had minimal anxiety, 26.7% borderline anxiety, 17.5% mild anxiety, the same percentage of respondents moderate, 5% severe, while 2.5% had extreme anxiety based on BAI. Conclusion. Anxiety can be considered as potentially significant modulators of changes in brain structures observed in people with tinnitus.

Introduction. Higher level of knowledge and frequent contacts with peers with disabilities can influence the emergence of more positive attitudes of students towards peers with disabilities. In regard to that, our aim was to test the importance of knowledge, contact frequency and other possible factors influencing attitudes of students toward disabled peers. Methods. The study included 140 students of 4th and 5th grade of primary schools. The research was conducted in the period from December 2020 to March 2021 in two primary schools. The Chedoke McMaster scale was used to examine students' attitudes toward peers with disabilities, while Contact with Disabled Persons Scale and the Children's Knowledge about Handicapped Persons Scale were used to assess frequency of contact and knowledge about disabilities. Results. Girls showed a significantly higher level (25.21±6.21) of frequency of contacts with students with disabilities compared to boys (19.66±7.30) (p=0.043) and higher level of knowledge (27.88±5.88) about disabilities compared to boys (25.50±4.69) (p=0.009). Respondents who attended school together with children with disabilities (31.07 ± 8.41) showed a significantly higher level of frequency of contacts with students with disabilities compared to respondents who did not attend school with peers with disabilities (13.72±6.32) (p=0.001). Conclusion. Higher level of knowledge and frequent contacts with peers with disabilities does not have influence on the emergence of more positive attitudes of students towards peers with disabilities.

Introduction. Inhalation of coal dust during blasting in brown coal mines has been shown to lead to a lung disease called pneumoconiosis. There is very little data in the literature on the direct impact of coal on the quality of life of people who work in coal mines as well as the body's immune response to the effects of coal dust. The aim was to examine the immune response to exposure to coal dust in miners in a brown coal mine and whether mine workers have poorer quality of life compared to those not exposed to coal dust. Methods. This is a cross-sectional study among 100 employees in the Brown Coal Mine in Ugljevik, of which 50 of them are exposed to coal dust on a daily basis. Blood samples were taken from all subjects to test for the presence of cytokines IL-2, 4, 5, 9, 10, 13, 17A, 17F, 21, 22, IFN-g and TNF-a. The quality of life of employees was measured using a questionnaire for self-assessment of physical and mental health (36-item Short-Form Health Survey, SF-36). Results. Group of miners had a significantly (p<0.05) higher concentrations of pro-inflammatory cytokines IL-6, IFN-g, IL-17A and IL-22 when compared to the control group. Subjects from the control group had significantly (p<0.05) higher concentrations of anti-inflammatory cytokines IL-4 and IL-10 when compared to the group of miners. The quality of life was significantly (p<0.05) better in the control group when compared to the group of miners. Conclusion. Physical functioning, general health, mental health and Physical component summary were significantly poorer in the group of miners. Exposition to coal dust led to a significant increase in the production of pro-inflammatory cytokines and a decrease in the production of anti-inflammatory cytokines.

INTRODUCTION Hepatitis C Virus (HCV) is the leading cause of chronic liver disease and is a serious global health problem. Hepatitis C infection is highly prevalent in patients with end stage renal disease (ESRD), due to frequent exposure to blood and blood products, nosocomial transmission of HCV, and prolong hemodialysis duration. The aim of the study was to evaluate the influence of IL-33/ST2 signaling pathway on severity of the liver disease in ESRD HCV+ patients. METHODOLOGY Blood samples from patients with end stage renal disease (ESRD) and hepatitis C infection (HCV), 20 patients with HCV infection, 20 patients with ESRD and 20 healthy control donor patients were taken for the examination of biochemical parameters, for the determination of the serum cytokine concentration, and for the molecular diagnostics of HCV. RESULTS Systemic sST2 positively correlated with serum level of urea and creatinine, respectively. Serum sST2 was significantly increased in ESRD HCV+ patients in comparison to HCV+ group. sST2/IL-1, sST2/IL-4 and sST2/IL-23 ratios were significantly increased in serum of ESRD HCV+ patients in comparison to HCV+ patients. Significantly higher systemic level of sST2 and sST2/IL-1 and sST2/IL-4 ratios were measured in ESRD patients compared to non-ESRD patients. CONCLUSION These results suggested that elevated level sST2, as the consequence of renal failure, causes less destruction of liver in HCV infection.

Introduction. Cellulose nanocrystals (CNCs) as attractive natural materials,have numerous applications in the biomedical field. Their unique biomechanicalcharacteristics, surface chemistry, low cost and sustainable naturemake them an engaging alternative to conventional materials and potentiatetheir use as progressive material. Therefore, it is critical to evaluate thecytocompatibility and immunomodulatory properties of nCNCs, which havenot been completely explored. The objective of this study was to examinea dose-dependent effect of native (n)CNCs on cytotoxicity and proliferativeactivity of human peripheral blood mononuclear cells (PBMNCs) in vitro.Methods. PBMNCs, obtained from the healthy blood donors, were cultivatedwith nCNCs. Cell viability was analyzed by flow cytometry assay, whileproliferative activity was determined by MTT, [3H]-thymidine uptake assayand detection of IL-2 production.Results. The cytotoxicity results suggested that no concentration of nCNCs(50-400 μg/ml) affected necrosis of PBMNCs, whereas apoptosis was inducedby the highest concentration of nCNCs compared to control (p<0.05).Unexpectedly, the highest concentration of nCNCs increased the metabolicactivity of PHA-stimulated cells compared to control (p<0.05). In contrastto these findings, lower concentrations of nCNCs (50 μg/ml and 100 μg/ml)stimulated proliferation of PBMNCs (p<0.05 and p<0.001). It was followedby increased production of IL-2 (100 μg/ml) (p<0.001).Conclusion. The results suggest that non-cytotoxic concentrations of nCNCsmodulate the proliferative activity of human PBMNCs, a phenomenon whichhas not been published up to now and which is relevant for further studies.

Introduction. Human monocytes are heterogeneous and plastic cell population with the ability to undergo phenotypic and functional changes as a response to a stimulus from a local microenvironment. Our aim was to determine the potential of human monocytes to differentiate into different cell populations depending on two different cytokines (IL-4 and IL-6) added to cultures as well as to compare their phenotypical and functional characteristics. Methods. Peripheral blood mononuclear cells (PBMNC) were isolated from buffy coats of healthy donors. Monocytes, which were separated from PBMNC by plastic adherence, had been cultivated in Dendritic cell (DC), serum free medium for 5 days, either with granulocyte/macrophage colony-stimulating factor (GM-CSF) alone or with GM-CSF, with addition of interleukin 4 (IL-4) or interleukin 6 (IL-6), respectively. After cultivation, phenotypic characteristics of these cells were analyzed by flow cytometry, whereas the levels of produced cytokines in culture supernatants were quantified by ELISA. The potential of differentiated cells to modulate the proliferation of allogeneic T cells was examined by co-cultivation of these cells with PBMNC. Results. GM-CSF differentiated monocytes into M0/M1 macrophages (MØ). The combination of GM-CSF and IL-4 favoured differentiation of immature DC, whereas GM-CSF and IL-6 transformed monocytes into monocytic myeloid derived suppressor cells (M-MDSC). All cell populations expressed typical monocyte/macrophage markers such as CD14, CD11b, CD16 and CD33, HLA-DR, CD209 and CD86, a co-stimulatory marker. DC and M-MDSC expressed CD1a and CD11c, in contrast to M0/M1 MØ. The expression of HLA-DR, CD1a, CD209 and CD86 was highest on DC. The expression of CD33 and CD16 was highest on M-MDSC, followed by lowest expression of HLA-DR. The potential of promoting T-cell proliferation was highest in cultures of PBMNC with DC, whereas M-MDSC had the opposite, suppressive, effect. These differences correlated with highest production of immunosuppressive cytokines such as IL-10, IL-27 and TGF-b by M-MDSC. Conclusion. This study confirmed the differentiation plasticity of human monocytes, which are influenced by cytokines added in cultures. Phenotypic characteristics of these cells correlated with the production of cytokines involved in modulation of T-cell proliferation.

Progress in diagnosis and treatment has led to a significant improvement in the fate of children born with tetralogy of Fallot, with the perioperative mortality of 2-3% and a 30-year survival rate of 90%. However, the majority of these patients have residual postoperative morphological and hemodynamic disorders, as well as heart rhythm disorders, primarily due to the volume loading of the right ventricle caused by chronic pulmonary regurgitation. Improved surgical techniques have reduced early mortality to less than 3%, but the annual mortality rate has increased 20-30 years after initial surgical remediation, mainly due to unwanted cardiac events. In longitudinal monitoring of patients after repair of tetralogy of Fallot, early detection of morphological and hemodynamic residual disorders both in asymptomatic and symptomatic patients is of great importance. The purpose of this is a timely identification of new therapeutic measures (e.g. pulmonary valve replacement) in order to improve the course and outcome of treatment. Cardiovascular magnetic resonance imaging is a diagnostic method that provides the most precise and accurate estimation of individual parameters of cardiac dysfunction and poor outcomes. Furthermore, it plays a significant role in defining the predictive ability of individual parameters. Previous research has shown that the increase in mortality risk coincides with progressive dilation and right ventricular dysfunction, by means of ventriculo-ventricular interaction and left ventricular dysfunction. Identification of parameters that can predict the high-risk patients for future unwanted cardiac events such as ventricular tachycardia and cardiac insufficiency can assist the customization of a therapeutic approach leading to improvement in quality of life and patient's survival rate.

Myeloid-derived suppressor cells (MDSC) emerged as major factors driving the tumor progression due to numerous immunosuppressive mechanisms they possess. Prostaglandin (PG)E2 is shown critical for the induction of MDSC and their suppressive functions in vivo, but it is poorly understood how it affects the capacity of MDSC to induce different subsets of regulatory T cells (Treg). By using a novel protocol for the generation of mononuclear (M)-MDSC, we showed that PGE2 potentiates the GM-CSF/IL-6-dependent induction of CD33+CD11b+HLA-DR−CD14+ M-MDSC in vitro. PGE2 diminished the capacity of GM-CSF/IL-6 M-MDSC to produce proinflammatory cytokines upon activation and augmented their capacity to produce IL-27, IL-33, and TGF-β. These results correlated with an increased potential of GM-CSF/IL-6/PGE2 M-MDSC to suppress T cell proliferation, expand alloreactive Th2 cells, and reduce the development of alloreactive Th17 and cytotoxic T cells. Interestingly, GM-CSF/IL-6/PGE2 M-MDSC displayed a lower capacity to induce TGF-β-producing FoxP3+ regulatory Treg compared to GM-CSF/IL-6 M-MDSC, as a consequence of reduced IDO-1 expression. In contrast, GM-CSF/IL-6/PGE2 M-MDSC potentiated IL-10 production by CD8+T, Th2, and particularly CD4+FoxP3− type 1 Treg, the latter of which depended on ILT3 and ILT4 expression. Cumulatively, PGE2 potentiated the suppressive phenotype and functions of GM-CSF/IL-6-induced M-MDSC and changed the mechanisms involved in Treg induction, which could be important for investigating new therapeutic strategies focused on MDSC-related effects in tumors and autoimmune diseases.

In 2012, alcohol liver disease resulted in 3.3 million—5.9% of global deaths. This study introduced whey protection capacity against chronic alcohol-induced liver injury. Rats were orally administered to 12% ethanol solution in water (ad libitum, average 8.14 g of ethanol/kg body weight (b.w.)/day) alone or combined with whey (per os, 2 g/kg b.w./day). After 6-week treatment, chronic ethanol consumption induced significant histopathological liver changes: congestion, central vein dilation, hepatic portal vein branch dilation, Kupffer cells hyperplasia, fatty liver changes, and hepatocytes focal necrosis. Ethanol significantly increased liver catalase activity and glutathione reductase protein expression without significant effects on antioxidative enzymes: glutathione peroxidase (GPx), copper–zinc-containing superoxide dismutase (CuZnSOD) and manganese-containing superoxide dismutase (MnSOD). Co-treatment with whey significantly attenuated pathohistological changes induced by ethanol ingestion and increased GSH-Px and nuclear factor kappa B (NF-κB) protein expression. Our results showed positive effects of whey on liver chronically exposed to ethanol, which seem to be associated with NF-κB-GPx signaling.