Dejan Nesic | University of Belgrade (original) (raw)

Papers by Dejan Nesic

Association between Chromatin Structural Organization of Peripheral Blood Neutrophils and Self-Perceived Mental Stress: Gray-Level Co-occurrence Matrix Analysis, 2021

Methods based on the evaluation of textural patterns in microscopy, such as the "gray-level co-oc... more Methods based on the evaluation of textural patterns in microscopy, such as the "gray-level co-occurrence matrix" (GLCM) analysis are modern and innovative computer and mathematical algorithms that can be used to quantify subtle structural changes in cells and their organelles. Potential application of GLCM method in the fields of psychophysiology and psychiatry to this date has not been systematically investigated. The main objective of our study was to test the existence and strength of the association between chromatin structural organization of peripheral blood neutrophils and levels of self-perceived mental stress. The research was done on a sample of 100 healthy student athletes, and the Depression, Anxiety, and Stress Scales (DASS-21) were used for the estimation of psychological distress. Chromatin textural homogeneity and uniformity were negatively correlated (p < 0.01) with mental distress and had relatively good discriminatory power in differentiating participants with normal and elevated stress levels. As an addition, we propose the creation of a machine learning model based on binomial logistic regression that uses these and other GLCM features to predict stress elevation. To the best of our knowledge, these results are one of the first to establish the link between neutrophil chromatin structural organization quantified by the GLCM method and indicators of normal psychological functioning.

Central European Journal of Public Health, Jun 30, 2023

Objectives: Healthcare workers are the professional group at higher risk of burnout than others. ... more Objectives: Healthcare workers are the professional group at higher risk of burnout than others. It is the underlying reason for medical errors and the general decrease in quality of patient care and is related to poor patient-healthcare worker relationships. Healthcare workers who work with military personnel have specificities compared to healthcare workers who work only with civilians. Methods: A cross-sectional study among 171 nurses at the Military Medical Academy was conducted. The questionnaire consisted of items regarding socio-demographic and socioeconomic characteristics, lifestyle characteristics, workplace environment, workplace stress, strategies of stress management, symptoms and signs of workplace-related stress, and the Serbian version of the Maslach Burnout Inventory. Results: The prevalence of burnout was 46.2%. The multivariate logistic regression analysis showed that the burnout was associated with stating that they would not choose the same profession again (OR = 4.54, 95% CI: 1.53-14.50) and with not being interested in the work (OR = 4.86, 95% CI: 1.58-14.92). Conclusion: The prevalence of burnout is relatively high among nurses at the Medical Military Academy in Belgrade and is associated with factors in the work environment.

Frontiers in Bioengineering and Biotechnology, May 26, 2023

Decellularized corneas offer a promising and sustainable source of replacement grafts, mimicking ... more Decellularized corneas offer a promising and sustainable source of replacement grafts, mimicking native tissue and reducing the risk of immune rejection posttransplantation. Despite great success in achieving acellular scaffolds, little consensus exists regarding the quality of the decellularized extracellular matrix. Metrics used to evaluate extracellular matrix performance are study-specific, subjective, and semi-quantitative. Thus, this work focused on developing a computational method to examine the effectiveness of corneal decellularization. We combined conventional semi-quantitative histological assessments and automated scaffold evaluations based on textual image analyses to assess decellularization efficiency. Our study highlights that it is possible to develop contemporary machine learning (ML) models based on random forests and support vector machine algorithms, which can identify regions of interest in acellularized corneal stromal tissue with relatively high accuracy. These results provide a platform for developing machine learning biosensing systems for evaluating subtle morphological changes in decellularized scaffolds, which are crucial for assessing their functionality.

Archives of Biological Sciences, 2023

Hemodialysis (HD) removes nitrogenous waste products from patients' blood through a semipermeable... more Hemodialysis (HD) removes nitrogenous waste products from patients' blood through a semipermeable membrane along a concentration gradient. Near-infrared spectroscopy (NIRS) is an underexplored method of monitoring the concentrations of several molecules that reflect the efficacy of the HD process in dialysate samples. In this study, we aimed to evaluate NIRS as a technique for the non-invasive detection of uremic solutes by assessing the correlations between the spectrum of the spent dialysate and the serum levels of urea, creatinine, and uric acid. Blood and dialysate samples were taken from 35 patients on maintenance HD. The absorption spectrum of each dialysate sample was measured three times in the wavelength range of 700-1700 nm, resulting in a dataset with 315 spectra. The artificial neural network (ANN) learning technique was used to assess the correlations between the recorded NIR-absorbance spectra of the spent dialysate and serum levels of selected uremic toxins. Very good correlations between the NIR-absorbance spectra of the spent dialysate fluid with serum urea (R=0.91) and uric acid (R=0.91) and an excellent correlation with serum creatinine (R=0.97) were obtained. These results support the application of NIRS as a non-invasive, safe, accurate, and repetitive technique for online monitoring of uremic toxins to assist clinicians in assessing HD efficiency and individualization of HD treatments.

Scandinavian Journal of Laboratory Animal Science, 2007

Peritoneal dialysis (PD) is a treatment method for patients with end-stage renal insufficiency. I... more Peritoneal dialysis (PD) is a treatment method for patients with end-stage renal insufficiency. Its efficacy and possibility for at-home performance make it the treatment of choice for many patients (Blake, 2001; Trbojevic et al. 2001). It is especially recommended for elderly persons, patients with insulindependent diabetes or heart disease (Stojimirovic and Nesic, 1998). The main goal of this treatment is to achieve complete social and physical rehabilitation of the patient. The main elements of the PD system are the peritoneal vascular network, peritoneal membrane and dialysis solution in the peritoneal cavity. Dialysis solution is instilled continuously or intermittently into the peritoneal cavity through a surgically implanted catheter in the front abdominal wall. Water and solute exchange between this solution and the patient's blood is achieved by osmosis and diffusion. These processes occur through the peritoneal barrier consisting of a stagnant fluid layer within the peritoneal capillaries, the capillary endothelium and basement membrane, the interstitium, the mesothelium and the stagnant fluid layer within the peritoneal cavity. In this way PD substitutes at least two of the impaired renal functions in uremic patients: evacuation of degradation products accumulated in the blood and removal of excess water (Stojimirovic and Nesic, 1998). Mesothelium is damaged by uremic changes in the internal environment, while PD additionally injures the peritoneum (Obradovic et al., 2000; Stojimirovic et al., 2000). Continuous exposure to hyperosmolar dialysis solution with low pH and high glucose concentration causes various pathological changes in the peritoneal membrane structure. Frequent peritonitis episodes further damage this fragile tissue (Stojimirovic et al., 2001a, 2001b). Limitations in researches of human peritoneum and advantages of animal models Increasing employment of PD in treating patients with end-stage renal failure imposed the need for better understanding of the structure and physiology of healthy human peritoneum, as well as changes caused by PD the process (Stojimirovic et al., 2002). Researches on human material, however, carry a number of technical and ethical problems

Opšta medicina, 2000

... 6, br. 1-2, str. 35-40. jezik rada: srpski saoptenje. Faktori koji određuju seksualno ponaa... more ... 6, br. 1-2, str. 35-40. jezik rada: srpski saoptenje. Faktori koji određuju seksualno ponaanje mladih. Neić Dejan a , Jović Stevan b , Nikolić Gordana c , Mrvaljević Milutin a , Lačković Maja a. ... VBS. Marić, J. (1998) Ljubav, seks i depresija - mali priručnik za srećniji ivot. ...

Acta Veterinaria-beograd, 2002

Archives of Biological Sciences, 2022

The study aimed to assess the oncologic and reproductive outcome of fertility-sparing treatment o... more The study aimed to assess the oncologic and reproductive outcome of fertility-sparing treatment of stage I borderline ovarian tumors (BOTs). A retrospective study of patients aged 18-40 years with stage I BOTs surgically treated during a 10-year period was conducted. In total, 52 patients (average age 32.7+/-5.9) were followed for 16 to 137 months after BOT diagnosis (mean 73.4 months). The overall survival rate was 100%. Recurrence was registered in 4 patients (7.7%). All patients underwent a unilateral salpingo-oophorectomy and all histologic findings corresponded with primary BOTs (3 serous; 1 endometrioid). Higher parity increased while the histological type and stage did not impact recurrence. Average recurrence-free survival was 36.2+/-23.6 months regardless of histological type and stage. Recurrence occurred during the first 3 postoperative years in 75% of cases. Out of 45 women treated with fertility-sparing surgery, 64.4% attempted pregnancy and the pregnancy success rate was 44.8%. Only one pregnancy was conceived by assisted reproduction, while all others were spontaneous. The fertility-sparing treatment in stage I borderline ovarian tumors can be a safe and successful option both in terms of oncologic and reproductive outcomes, regardless of patient and treatment characteristics. Pregnancies after BOT surgery can be achieved with satisfactory rates and adequate outcomes.

Zdravstvena zaštita, 2006

Sa`etak. U radu se kroz analiti~ki pristup raspravqa o kvalitetu `ivota starijih osoba, ra{~lawen... more Sa`etak. U radu se kroz analiti~ki pristup raspravqa o kvalitetu `ivota starijih osoba, ra{~lawenom na wegove osnovne komponente: fizi~ka funkcija, mentalni status, te`ina simptoma, li~ni ose}aj zdravstvenog stawa i socijalna funkcija. Pri tome se polazi od ~iwenice da su fi-zi~ka funkcija i mentalni status neposredno zdravstveno uslovqeni ~inioci kvaliteta `ivota, za razliku od socijalne funkcije koja predstavqa zna~ajan aspekt ukupnog kvaliteta `ivota, ali nije u sklopu zdravstveno-relevantnih funkcija. Zbog toga se kvalitet `ivota ne mo`e jasno definisati, ali je jasno da se ne mo`e izjedna~iti sa zdravqem, jer je to mnogo {iri pojam od zdravqa.

Archives of Biological Sciences, 2019

Vascular endothelial growth factor (VEGF), a powerful angiogenetic agent crucial for microvascula... more Vascular endothelial growth factor (VEGF), a powerful angiogenetic agent crucial for microvascular hyperpermeability and neoangiogenesis in the peritoneum, is associated with increased solute transport rates in chronic peritoneal dialysis (PD) patients. We investigated the correlation between serum and drained dialysate (dd) concentrations of VEGF and the transport characteristics of peritoneal membrane and dialysis quality in 20 patients with end-stage renal failure at the beginning and after six months of PD. The serum VEGF (sVEGF) concentration rose significantly (149.33±116.71 pg/ mL vs 239.36±102.23 pg/mL; p=0.012) and ddVEGF concentration increased slightly (38.44±50.47 pg/mL vs 43.55±51.10 pg/mL) during the first 6 months of PD. At the beginning of chronic PD, ddVEGF concentrations correlated inversely with the peritoneal equilibrium test (PET) glucose (R=-0.565; p=0.009) and creatinine (R=-0.506; p=0.023) and residual renal function (RRF) (R=-0.691; p=0.001); sVEGF concentrations inversely correlated with PET creatinine (R=-0.457; p=0.043) and residual diuresis (RD) (R=-0.691; p=0.001). After 6 months of treatment, ddVEGF concentrations correlated directly with PET creatinine (R=0.450; p=0.047), and inversely with RRF (R=-0.552; p=0.012) and residual renal weekly Kt/V (R=-0.488; p=0.029). The sVEGF concentration inversely correlated with RD (R=-0.589; p=0.006). High ddVEGF at the beginning of PD is predictive of adverse alterations of the peritoneal membrane, i.e. increased transport rate of glucose and creatinine. ddVEGF values may help to identify patients who will preserve adequate transport characteristics of the peritoneal membrane and maintain successful long-term PD.

Opšta medicina, 2003

Cervix cancer occupies the third place after breast cancer and colon cancer white malignant tumor... more Cervix cancer occupies the third place after breast cancer and colon cancer white malignant tumors of the body uterus are in the fourth place. It is the most frequent tumor of female sexual organs. Aim of this study is to show the percentage of mortality of women caused ...

Medicinska istraživanja, 2022

After the outbreak of the novel SARS-COV-2 coronavirus, in the Chinese province of Wuhan that spr... more After the outbreak of the novel SARS-COV-2 coronavirus, in the Chinese province of Wuhan that spread rapidly across the world, the Government of the Republic of Serbia introduced protection measures in March 2020, to prevent the spread of the infectious disease COVID-19 in Serbia. All gatherings indoors (sport, cultural and other events), as well as in parks and public places intended for recreation and sports, were prohibited. Shortly after, a lockdown took place which prohibited leaving home with the exception of basic needs, work from home was recommended and online schooling was introduced. The World Health Organization has recommended the use of online resources to maintain basic physical activity. In these circumstances of social distancing, this study examines the prevalence of physical activity supported by social networks and mobile applications during the COVID-19 lockdown in Serbia. The study was conducted as a cross-sectional study, using questionnaire distributed through social networks. The study found that more than a third of respondents (38.3%) used social networks or mobile apps to perform physical activity during the lockdown in Serbia; 27.1% used social networks/mobile apps before the pandemic, while 11.2% began to use social networks/mobile apps to perform physical activity during the lockdown. Easy access and review of exercises were the most common reasons for using social networks/mobile apps. 40% of the participants in the study agreed that social networks/mobile apps, make it easier to engage in physical activity. Based on the presented results, it can be concluded that the promotion of physical activity at home through social networks and mobile apps can provide an invaluable contribution to maintaining physical activity globally during pandemics such as COVID-19.

Medicinski Podmladak, 2022

Tendons are the soft tissue that connects muscles to bones. They are made of collagen and elastin... more Tendons are the soft tissue that connects muscles to bones. They are made of collagen and elastin, they are strong and solid, and have no possibility of contraction. Their strength helps us to move. Recovery of tendon injuries is long-lasting and can take more than six months. If a tendon is shed during a time injury, calcification occurs at the site of the injury and the disease is called calcifying tendinopathy. The very existence of calcifications is an indication for treatment with a mechanical shock wave (Shock wave). Mechanical shock waves can act in focus or radially. The difference between focused and radial waves is primarily in their physical basis. Focused shock waves differ from radial shock waves in terms of therapeutic depth of penetration into the tissue. The basic biological effect of a mechanical shock wave is stimulating. The energy of the mechanical shock wave acts at the cellular level by stimulating the reduction of inflammation and pain in the tissue. Using mechanical shock wave in the treatment of calcified tendinopathies, a safe method for breaking calcifications was obtained. Shock wave can be applied to using: different frequency, different number of strokes, as well as different strength of strokes in their studies. The choice of parameters for the application depends on whether it is calcified or non-calcified tendinopathy. Indications for the use are: painful shoulder, heel spur, plantar fasciitis, tennis elbow, Achilles tendon tendinopathy, jumping knee, patellar tendinitis, myalgia, myogelosis and muscular tendon overstrain syndrome. Contraindications for the use are: the existence of prostheses, knees and hips, as well as various orthopedic material, pacemaker, as well as the presence of chronic diseases such as multiple sclerosis, amyotrophic lateral sclerosis or tumors. The application of a mechanical shock wave is new, non-invasive method, easy to apply, always reduces pain and practically without side effects. This method has a special role in the treatment of chronic inflammation of diseased tendons, with or without calcification. The only dilemma in the application of a mechanical shock wave can be in the number of applications as well as the time break between the applications of two consecutive mechanical shock waves therapy.

OXYGEN UPTAKE AT VENTILATORY THRESHOLD AND VO2MAX, BEFORE AND AFTER EIGHT WEEKS OF ENDURANCE TRAI... more OXYGEN UPTAKE AT VENTILATORY THRESHOLD AND VO2MAX, BEFORE AND AFTER EIGHT WEEKS OF ENDURANCE TRAINING Purpose: The subject of the research was to compare oxygen uptake at ventilatory threshold with maximal oxygen uptake (VO2max), before and after eight weeks of endurance training. Methods: 32 male subjects (age: 22.3 ± 2.5 yr, height: 179.8 ± 7.6 cm, body mass: 76.8 ± 9.0 kg) performed a progressive test to measure ventilatory threshold (VT) and VO2max on treadmill. After 8 weeks of endurance training (3 times per week, duration between 30 and 70 min, in different zones in respect to the ventilatory threshold), subjects do the same test. Results: Oxygen uptake at ventilatory threshold increased significantly (p=0.0001), between initial and final measures (34.8 ± 6.3 mlO2/kg/min, 41.3 ± 6.2 mlO2/kg/min, respectively); same as VO2max (52.1 ± 5.9 mlO2/kg/min, 57.1 ± 5.3 mlO2/kg/min, respectively). At initial test, oxygen uptake at ventilatory threshold was 66.3 ± 6.6 % of maximal oxygen uptake (VO2max). At final test, oxygen uptake at ventilatory threshold was 72.1 ± 6.3% of maximal oxygen uptake. Oxygen uptake at ventilatory threshold were significantly greater at final test (p=0.001), when expresed in percentage of maximal oxygen uptake. Discusion: Oxygen uptake at ventilatory threshold were significantly greater after eight weeks of endurance training (p=0.001), when expresed both in absolute values and in percentage of maximal oxygen uptake (VO2max). Conclusions: Comparison between initial and final tests demonstrated significant increase of observed variable, under the influence of experimental treatment: oxygen uptake at the ventilatory threshold were greater at final test, in absolute values and when expresed in percentage of maximal oxygen uptake (VO2max).

Serbian Journal of Anesthesia and Intensive Therapy, 2016

Uvod: Tramadol i metamizol se često primenjuju u terapiji akutnog postoperativnog bola (bolus doz... more Uvod: Tramadol i metamizol se često primenjuju u terapiji akutnog postoperativnog bola (bolus doze). Kombinovana intravenska primena tramadola/metamizola predstavlja bezbedan i efikasan analgetski metod, a u kliničkoj praksi nisu dokazane farmakokinetske i farmakodinamske interakcije. Morfin-sulfat je najčešće korišćen analgetik na zahtev. Metodologija: Nakon dobijanja saglasnosti od strane lokalnog etičkog odbora i saglasnosti pacijenata, sprovedena je prospektivna kohortna pilot-studija koja je obuhvatila pacijente podvrgnute radikalnoj nefrektomiji pristupom putem lumbotomije. Pacijenti normalnog Mini-Mental skora i ASA I i II grupe su uključeni u studiju. Iz studije su izuzeti pacijenti oboleli od dijabetes melitusa, depresije, sa bubrežnom slabošću, sa hematološkim poremećajima, peptičkim ulkusom, sa istorijom zloupotrebe medikamenata ili hroničnom upotrebom opioida, sa alergijskim reakcijama na neki od lekova. Svi pacijenti su primili istu premedikaciju i bili su podvrgnuti operativnom zahvatu u opštoj endotrahealnoj anesteziji. Indukcija anestezije je izvedena propofolom 2 mg/kg i fentanilom (0,005 mg/kg), a održavana sevofluranom (1 MAC) i rokuronijumom. Nisu zabeležene komplikacije hirurške procedure. Postoperativno, pacijenti su bili podeljeni u 2 grupe. Grupa I je primala i.v. infuziju 100 mg tramadola na 6 sati i infuziju metamizola 2500 mg na 12 sati, naizmenično. Analgetska sekvenca je započeta tramadolom, a nastavljena metamizolom kroz 2 sata. Grupa II je primila tramadol 400 mg (0,8 mg/ml) i metamizol 5000 mg (10 mg/ml) rastvorene Sumarry Introduction: Tramadol and metamizol are very commonly used postoperatively for acute pain (bolus doses). Combined iv infusion tramadol/metamizol provide safe and effective acute pain relief and there is no evidence for pharmacokinetic and pharmacodynamic side effects in clinical practice. Morphine sulfate seems to be the best rescue analgesic for patients receiving this infusion. Methods: After approval of local ethic committee and written ICF, the prospective cohort pilot study included all patients undergoing surgery (radical nephrectomy with lumbotomy approach). ASA physical status I to III and normal minimental score patients were included. Patients suffered from diabetes melitus, depressive disorders, advanced renal failure, hematology disease, peptic ulcer, drug abuse or chronic opioid use, medicament allergic reaction were excluded. All patients who underwent surgery under general anesthesia recieved the same premedication. Anaesthesia induction was made with propofol in dose 2 mg/ kg followed by sevoflurane (1MAC), fentanyl (0,005 mg/ kg) and rocuronium 0,6 mg/kg for intubation. Complications of surgical procedures have not occurred. Postoperatively, patients were randomized into two groups. Group I received iv infusion of tramadol 100 mg qd and metamizol-Na 2500 mg bid in bolus doses. Analgesia started with tramadol 100 mg followed by metamizol 2500 mg after 120 minutes. Group II received the solution tramadol 400 mg (0,8 mg/ml) and metamizol 5000 mg (10 mg/ml) in 500 ml normal saline. Infusion rate was 200 ml/h first 30 minutes

Experimental Biology and Medicine, Nov 1, 2006

Public Health, Sep 1, 2019

Objectives: Physical activity level decreases during young adulthood. As social media are nowaday... more Objectives: Physical activity level decreases during young adulthood. As social media are nowadays widely used and are included into many people's daily routines, the interventions on these websites have the possibilities to be integrated into those routines without becoming a burden. The aim of this study was to assess physical activity level among first-and fifth-year medical students and social media intervention with the aim to improve physical activity among them.

BioMed Research International

The prospective, simple randomized study assesses the effect of focused extracorporeal shock wave... more The prospective, simple randomized study assesses the effect of focused extracorporeal shock wave therapy (f-ESWT) on pain intensity and calcification size compared to the application of ultrasound physical therapy in treating patients with calcar calcanei. A total of 124 patients diagnosed with calcar calcanei were consecutively included in the study. The patients were divided into two groups: the experimental group ( n = 62 ), which included the patients treated with f-ECWT, and the control group ( n = 62 ), consisting of patients treated with the standard ultrasound therapy method. The experimental group’s patients received ten therapy applications spaced seven days apart. The patients in the control group had ten ultrasound treatments on ten consecutive days over two weeks. All patients in both groups were tested using the Visual Analog Scale (VAS) to measure pain intensity before the beginning and at the end of treatment. The size of the calcification was assessed in all patien...