Djordje Kolak

Dr. Djordje Kolak

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Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

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

Representative Publications

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Verified
Journal Article
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DKDragan Radenko Knezevic
Dragan Radenko Knezevic
VZVladimir Zivkovic
Vladimir Zivkovic
Vladimir JakovljevicVladimir Jakovljevic
Vladimir Jakovljevic
NMNikola Mirkovic
Nikola Mirkovic
MIMilena Ilić
Milena Ilić
DKDjordje Kolak
Djordje Kolak
Objective: Peripheral arterial occlusive disease (PAOD) is characterized by impaired tissue perfusion, chronic ischemia, and increased platelet reactivity. Hyperbaric oxygen therapy (HBOT) is used as adjunctive treatment in advanced PAOD, but its effect on platelet function remains insufficiently studied. This study examined the association between HBOT and platelet aggregation. Methods: This prospective observational study included 90 patients with Fontaine stage IV PAOD and chronic ulceration, assigned to an HBOT group (n = 60) or waiting-list control group (n = 30). Patients were predominantly male; mean age was 66.82 ± 9.42 years in the study group and 63.00 ± 8.31 years in controls, and diabetes mellitus was present in 55.0% and 63.3%, respectively. Prior revascularization included open surgery in 33.3% and 30.0%, endovascular treatment in 36.7% and 43.3%, and no option for revascularization in 30.0% and 26.7%, respectively. HBOT was administered over 4 weeks (20 sessions, 2.0–2.5 ATA). Platelet aggregation was measured by impedance aggregometry using arachidonic-acid-induced aggregation (ASPI), adenosine-diphosphate-induced aggregation (ADP), and thrombin-receptor-activating peptide-induced aggregation (TRAP) agonists. Changes were analyzed using generalized estimating equation models adjusted for antiplatelet therapy, diabetes mellitus, smoking, and C-reactive protein (CRP). Results: Significant group × time interactions were observed for all platelet activation pathways, indicating greater reductions in the HBOT group than controls: ASPI (β = −290.5; p < 0.001), ADP (β = −243.6; p < 0.001), and TRAP (β = −330.9; p < 0.001). No significant change was observed in controls. HBOT was associated with reduced pain intensity, while CRP and platelet-to-lymphocyte ratio (PLR) remained stable. Ulcer size showed no significant change after 4 weeks. Conclusions: In patients with PAOD, HBOT was associated with reduced platelet reactivity independent of antiplatelet therapy. Further randomized studies are needed to determine its clinical significance.

1 January 2025 in Srpski arhiv za celokupno lekarstvo
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Bojan MilenkovićBojan Milenković
Bojan Milenković
MBMiljan Bilanović
Miljan Bilanović
STSladjan Timotijevic
Sladjan Timotijevic
MTMiroslav Tatic
Miroslav Tatic
DKDjordje Kolak
Djordje Kolak
Introduction. Joint dislocation is the loss of congruence of the joint surfaces. This is a relatively common injury of the musculoskeletal injury. Among the large joints, shoulder joint dislocation has the highest incidence of 24/100,000/year, of which 94?97% are anterior, 1% are inferior, and the remaining injuries are posterior shoulder dislocations. The second most frequent injury is elbow dislocation, with an incidence of 5.2/100,000/year. Among these, over 80% are posterolateral dislocations. Case outline. A 57-year-old female patient was injured during an accidental ground-level fall sustaining combined injuries ? anterior dislocation of the shoulder joint and a posterolateral dislocation of the elbow joint. Upon sustaining the described injuries, she was treated conservatively with good functional results. Conclusion. A review of the literature reveals that the combination of ipsilateral shoulder and elbow joint dislocations is a rare injury, with shoulder dislocation often being overlooked. Proper anamnesis, along with a thorough examination of the joints both proximally and distally to the injured joint, is crucial. If performed adequately, these injuries can often be successfully managed nonoperatively, with closed reduction, immobilization, and rehabilitation, leading to satisfactory functional recovery.

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ZSZeljko Stepanovic
Zeljko Stepanovic
BRBranko Ristic
Branko Ristic
AMAleksandar Matic
Aleksandar Matic
NPNikola S Prodanovic
Nikola S Prodanovic
JMJelena Milosevic
Jelena Milosevic
DKDjordje Kolak
Djordje Kolak
Background: The optimal route of tranexamic acid (TXA) administration remains one of the most debated topics in total knee arthroplasty. This study aimed to compare the effects of intravenous (IV), intra-articular (IA), and combined TXA protocols on total blood loss (TBL) and hidden blood loss (HBL), while identifying independent predictors of perioperative bleeding. Methods: In a prospective cohort study of 245 patients undergoing primary TKA, participants were assigned into four groups: IV TXA (15 mg/kg), IA TXA (1 g), combined (IV + IA), and a control group. TBL and HBL were calculated using the Gross formula. A multivariate linear regression model was used to assess independent associations of each protocol. Results: The IV group demonstrated significantly lower TBL (mean 898 mL) and HBL (mean 568 mL) compared with both the control (1329 mL and 894 mL; p = 0.002) and IA groups (1129 mL and 748 mL; p = 0.008). While IA TXA reduced 24 h drain output (p < 0.001), it did not significantly reduce TBL (p = 0.539) or HBL (p = 0.875). No significant differences were found between the IV-only and combined groups (p > 0.05). Multivariate regression identified the IV route as an independent predictor of reduced TBL (B = −383.7, p = 0.001). Conclusions: A single intravenous dose of TXA was associated with lower total and hidden blood loss compared with intra-articular administration. The lack of additional benefit in the combined group suggests a possible plateau effect of systemic administration, which is hypothesis-generating and limited by the study design for blood conservation in TKA. Level of Evidence: Level II, Prospective Cohort Study.

6 June 2026 in Obesities
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NPNela Papovic
Nela Papovic
NPNikola S Prodanovic
Nikola S Prodanovic
DKDjordje Kolak
Djordje Kolak
BVBiljana Pavla Vuletic
Biljana Pavla Vuletic
KDKaterina Dajic Dajic
Katerina Dajic Dajic
TPTijana V Prodanovic
Tijana V Prodanovic
Objective: To investigate the associations between body weight status and anthropometric parameters, lipid profile, eating behavior characteristics, and physical activity levels among children in a developing country. Methods: The study included 80 children aged 7–11 years, divided into two groups: children with normal body weight (n = 40) and children with overweight or obesity classified using WHO BMI-for-age growth reference standards (overweight >+1 SD, obesity >+2 SD). BMI, waist circumference, and lipid profile (total cholesterol, LDL, HDL, triglycerides) were measured. Eating behavior characteristics and physical activity levels were assessed using standardized questionnaires. Statistical analysis included descriptive statistics, comparative tests, correlation analysis, and exploratory regression models. Results: Children with increased body weight had significantly higher BMI, waist circumference, and a more unfavorable lipid profile (p < 0.01). BMI showed a positive correlation with food enjoyment, emotional overeating, and eating speed, and a negative correlation with satiety responsiveness and food fussiness. Lower physical activity levels were associated with higher BMI and higher total cholesterol in unadjusted analyses. Conclusions: Excess body weight among children in a developing country is associated with metabolic and behavioral characteristics in this sample. Given the cross-sectional design and limited sample size, findings should be interpreted as exploratory. The findings highlight associations between body weight status, metabolic parameters, eating behavior, and physical activity, without implying causality due to the cross-sectional design.