Hrvoje Omrčen

Dr. Hrvoje Omrčen

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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1 October 2021 in Brain Impairment
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Tanja Grubić KezeleTanja Grubić Kezele
Tanja Grubić Kezele
ZTZrinka Trope
Zrinka Trope
VAValentina Ahel
Valentina Ahel
NRNatali Ružić
Natali Ružić
HOHrvoje Omrčen
Hrvoje Omrčen
AFAriana Fužinac-Smojver
Ariana Fužinac-Smojver
Purpose: To examine the feasibility and possible effect of an 8-week exercise program on sleep quality, insomnia and psychological distress in individuals with multiple sclerosis (MS).Methods: Twenty-four individuals with MS were recruited into a controlled pre-post feasibility study and divided into 2 groups: exercise (n = 13; Expanded Disability Status Scale (EDSS): 1.0–7.5) and a related control group with no exercise (n = 11; EDSS: 1.0–7.0). The exercise group performed combined upper limb, lower limb and breathing exercises in a controlled group (2d/week, 60 min/session) for 8 weeks. Participants were administered measures to evaluate sleep quality (Pittsburgh Sleep Quality Index, PSQI), insomnia severity (Insomnia Severity Index, ISI), psychological distress (Clinical Outcomes in Routine Evaluation–Outcome Measure, CORE-OM) and additionally impact of fatigue (Modified Fatigue Impact Scale, MFIS) after 8-weeks.Results: Insomnia severity measured with ISI (F(1;22)=5.95, p = 0.023, ηp2 = 0.213, 90% CI = 0.02–0.42) and psychological distress measured with the CORE-OM (F(1;22)=4.82, p = 0.039, ηp2 = 0.179, 90% CI = 0.01–0.40) showed statistically significant group-by-time interaction. Sleep quality measured with the PSQI showed statistically significant group-by-time interaction only in an aspect of daytime sleep dysfunction (F(1;22)=5.33, p = 0.031, ηp2 = 0.195, 90% CI = 0.01–0.40). The fatigue impact measured with the MFIS showed statistically significant group-by-time interaction in physical (F(1;22)=6.80, p = 0.016, ηp2 = 0.236, 90% CI = 0.02–0.44) and cognitive aspects (F(1;22)=9.12, p = 0.006, ηp2 = 0.293, 90% CI = 0.05–0.49), and total score (F(1;22)=11.29, p = 0.003, ηp2 = 0.339, 90% CI = 0.08–0.52).Conclusions: Our 8-week program reduced insomnia severity, psychological distress and some aspects of fatigue (physical; cognitive; total), and improved sleep quality in an aspect of daytime sleep dysfunction in a small group of individuals with MS. Good feasibility and significant positive changes from baseline warrant further exploratory work.

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DPDarian Volarić, MD, PhD
Darian Volarić, MD, PhD
GŽGordana Žauhar
Gordana Žauhar
JCJie Chen
Jie Chen
ARANA TEREZIJA JERBIĆ RADETIĆ
ANA TEREZIJA JERBIĆ RADETIĆ
HOHrvoje Omrčen
Hrvoje Omrčen
Olga Cvijanović PelozaOlga Cvijanović Peloza
Olga Cvijanović Peloza
Low-intensity pulsed ultrasound (LIPUS) is a form of ultrasound that utilizes low-intensity pulsed waves. Its effect on bones that heal by intramembranous ossification has not been sufficiently investigated. In this study, we examined LIPUS and the autologous bone, to determine their effect on the healing of the critical-size bone defect (CSBD) of the rat calvaria. The bone samples underwent histological, histomorphometric and immunohistochemical analyses. Both LIPUS and autologous bone promoted osteogenesis, leading to almost complete closure of the bone defect. On day 30, the bone volume was the highest in the autologous bone group (20.35%), followed by the LIPUS group (19.12%), and the lowest value was in the control group (5.11%). The autologous bone group exhibited the highest intensities of COX-2 (167.7 ± 1.1) and Osx (177.1 ± 0.9) expression on day 30. In the LIPUS group, the highest intensity of COX-2 expression was found on day 7 (169.7 ±1.6) and day 15 (92.7 ± 2.2), while the highest Osx expression was on day 7 (131.9 ± 0.9). In conclusion, this study suggests that LIPUS could represent a viable alternative to autologous bone grafts in repairing bone defects that are ossified by intramembranous ossification.

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HOHrvoje Omrčen
Hrvoje Omrčen
SCSanja Zoričić Cvek
Sanja Zoričić Cvek
LBLara Baticic
Lara Baticic
SŠSandra Šućurović
Sandra Šućurović
Tanja Grubić KezeleTanja Grubić Kezele
Tanja Grubić Kezele
BMPs regulate synovial quiescence and adult neurogenesis in the hippocampus in non-stress conditions. However, changes in BMP expression that are induced by inflammation during rheumatoid arthritis (RA) have not yet been reported. Here, we show that signalling with synovial BMPs (BMP-4 and -7) mediates the effect of systemic inflammation on adult neurogenesis in the hippocampus during pristane-induced arthritis (PIA) in Dark Agouti (DA) rats, an animal model of RA. Moreover, we show gender differences in BMP expressions and their antagonists (Noggin and Gremlin) during PIA and their correlations with the clinical course and IL-17A and TNF-α levels in serum. Our results indicate gender differences in the clinical course, where male rats showed earlier onset and earlier recovery but a worse clinical course in the first two phases of the disease (onset and peak), which correlates with the initial increase of serum IL-17A level. The clinical course of the female rats worsened in remission. Their prolonged symptoms could be a reflection of an increased TNF-α level in serum during remission. Synovial inflammation was greater in females in PIA-remission with greater synovial BMP and antagonist expressions. More significant correlations between serum cytokines (IL-17A and TNF-α), and synovial BMPs and their antagonists were found in females than in males. On the other hand, males showed an increase in hippocampal BMP-4 expression during the acute phase, but both genders showed a decrease in antagonist expressions during PIA in general. Both genders showed a decrease in the number of Ki-67+ and SOX-2+ and DCX+ cells and in the ratio of DCX+ to Ki67+ cells in the dentate gyrus during PIA. However, in PIA remission, females showed a faster increase in the number of Ki67+, SOX-2+, and DCX+ cells and a faster increase in the DCX/Ki67 ratio than males. Both genders showed an increase of hippocampal BMP-7 expression during remission, although males constantly showed greater BMP-7 expression at all time points. Our data show that gender differences exist in the BMP expressions in the periphery–hippocampus axis and in the IL-17A and TNF-α levels in serum, which could imply differences in the mechanisms for the onset and progression of the disease, the clinical course severity, and adult neurogenesis with subsequent neurological complications between genders.

7 September 2018 in Transplantation Proceedings
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TĆTanja Ćelić
Tanja Ćelić
HOHrvoje Omrčen
Hrvoje Omrčen
JŠJosip Španjol
Josip Španjol
DBDragica Bobinac
Dragica Bobinac

18 September 2024 in Journal of Functional Biomaterials
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Marija ČandrlićMarija Čandrlić
Marija Čandrlić
ARANA TEREZIJA JERBIĆ RADETIĆ
ANA TEREZIJA JERBIĆ RADETIĆ
HOHrvoje Omrčen
Hrvoje Omrčen
BFBarbara Franović
Barbara Franović
LBLara Baticic
Lara Baticic
Olga Cvijanović PelozaOlga Cvijanović Peloza
Olga Cvijanović Peloza
The aim of this study was to evaluate the efficacy of autologous dentin (AD), bovine xenograft (BX) and magnesium-enriched bovine xenograft (BX + Mg) in the healing of critical cranial bone defects (CCBDs) in rats. Eighty male Wistar rats were divided into four groups: BX, BX + Mg, AD and the control group (no intervention). Eight mm CCBDs were created and treated with the respective biomaterials. Healing was assessed 7, 15, 21 and 30 days after surgery by micro-computed tomography (micro-CT), real-time polymerase chain reaction (RT-PCR) and immunohistochemical analysis. Micro-CT analysis showed that AD had the highest bone volume and the least amount of residual biomaterial at day 30, indicating robust bone formation and efficient resorption. BX + Mg showed significant bone volume but had more residual biomaterial compared to AD. RT-PCR showed that the expression of osteocalcin (OC), the receptor activator of nuclear factor κB (RANK) and sclerostin (SOST), was highest in the AD group at day 21 and vascular endothelial growth factor (VEGF) at day 15, indicating increased osteogenesis and angiogenesis in the AD group. Immunohistochemical staining confirmed intense BMP-2/4 and SMAD-1/5/8 expression in the AD group, indicating osteoinductive properties. The favorable gene expression profile and biocompatibility of AD and BX + Mg make them promising candidates for clinical applications in bone tissue engineering. Further research is required to fully exploit their potential in regenerative surgery.

Verified
Journal Article
Open access
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Tanja Grubić KezeleTanja Grubić Kezele
Tanja Grubić Kezele
HOHrvoje Omrčen
Hrvoje Omrčen
LBLara Baticic
Lara Baticic
SŠSandra Šućurović
Sandra Šućurović
SCSanja Zoričić Cvek
Sanja Zoričić Cvek
It is not entirely clear how the interaction between joint inflammation and the central nervous system (CNS) response in rheumatoid arthritis (RA) works, and what pathophysiology underlies the sex differences in coexisting neuropsychiatric comorbidities. It is known that estrogen hormones reduce inflammation in RA and that this occurs mainly via the stimulation of G protein-coupled receptor-30 (GPR30), also known as G protein-coupled estrogen receptor (GPER) 1. However, changes in GPR30 expression and sex differences induced by local and systemic inflammation in RA are not yet known. Our aim was to reveal sex differences in the expression and association of joint GPR30 with local and systemic inflammation, clinical course and furthermore with hippocampal GPR30 expression during pristane-induced arthritis (PIA) in Dark Agouti (DA) rats, an animal model of RA. Furthermore, we demonstrated sex-specific differences in the association between joint and systemic inflammation and hippocampal microglia during PIA. Our results suggest sex-specific differences not only in the clinical course and serum levels of pro-inflammatory cytokines but also in the expression of GPR30. Female rats show greater synovial inflammation and greater damage to the articular cartilage compared to males during PIA attack. Male rats express higher levels of synovial and cartilaginous GPR30 than females during PIA, which correlates with a less severe clinical course. The correlation between synovial and cartilaginous GPR30 and joint inflammation scores (Krenn and Mankin) in male rats suggests that the more severe the joint inflammation, the higher the GPR30 expression. At the same time, there is no particular upregulation of hippocampal GPR30 in males. On the other hand, female rats express higher levels of neuroprotective GPR30 in the hippocampus than male rats at the basic level and during PIA attack. In addition, females have a higher number of Iba-1+ cells in the hippocampus during PIA attack that strongly correlates with the clinical score, serum levels of IL-17A, and Krenn and Mankin scores. These results suggest that male rats are better protected from inflammation in the joints and female rats are better protected from the inflammation in the hippocampus during a PIA attack, independently of microglia proliferation. However, in the remission phase, synovial GPR30 expression suddenly increases in female rats, as does hippocampal GPR30 expression in males. Further experiments with a longer remission period are needed to investigate the molecular background of these sex differences, as well as microglia phenotype profiling.