Helena Čičak

Mrs. Helena Čičak

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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24 December 2022 in BMC Veterinary Research
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TKTara Kostanjšak
Tara Kostanjšak
Krunoslav BojanićKrunoslav Bojanić
Krunoslav Bojanić
HČHelena Čičak
Helena Čičak
JGJelena Gotić
Jelena Gotić
ZVZoran Vrbanac
Zoran Vrbanac
NBNika Brkljača Bottegaro
Nika Brkljača Bottegaro
Background: In human and veterinary medicine calprotectin is most widely used in diagnosing different gastro-intestinal diseases. The aim of this study was to assess the stability of canine calprotectin (cCP) in serum after storage at low temperatures and imprecision of the method. Methods: Blood samples were collected from dogs with different clinical diagnoses. Twenty-two dogs were included in this study. Calprotectin concentration was measured 4 hours after serum separation (T0), and after being frozen at − 80 °C for 8 (T1) and 16 weeks (T2). The maximum permissible difference (MPD) was derived from the equation for calculating total error (TE) TE = %Bias + (1.96 x %CV), where bias and coefficient of variation (CV) were defined by the manufacturer. The dogs enrolled in this study were patients admitted during the morning (9–12 a.m.), on the day the first measurement was performed. All sample analysis for determination of stability were done in duplicates. For determination of within-run precision, the two patients’ serum samples were analyzed in 20 replicates. Imprecision was assessed by analyzing 20 replicates on one plate on two samples where high and low concentrations were anticipated. Results: The calculated value of MPD was 32.52%. Median calprotectin concentrations were higher at T1 114.08 μg/L (IQR = 55.05–254.56) and T2 133.6 μg/L (IQR = 100.57–332.98) than at T0 83.60 μg/L (IQR = 50.38–176.07). Relative and absolute bias at T1 (49.3%; 45.98 μg/L) and T2 (109.93%; 94.09 μg /L) have shown that calprotectin concentrations increase after long term storage at − 80 °C. Conclusion: The results of the present study indicate that c-CP was not stable for 16 weeks at low storage temperature (− 80 °C). Considering the observed change in the concentration of c-CP at T1, a storage time of 8 weeks should be safely applied. The method imprecision was not satisfactory, especially in the lower concentration range.

15 February 2022 in Biochemia Medica
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HČHelena Čičak
Helena Čičak
PŠPavica Šonjić
Pavica Šonjić
AŠAna-Maria Šimundić
Ana-Maria Šimundić
Verification of automatic analysers Roller 20PN and iSED for measuring erythrocyte sedimentation rate

1 January 2024 in Biochemia Medica
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HČHelena Čičak
Helena Čičak
SBStjepan Bulat
Stjepan Bulat
JJJoško Jeličić
Joško Jeličić
AIAlan Ivković
Alan Ivković
KRKsenija Maštrović Radončić
Ksenija Maštrović Radončić
AŠAna-Maria Šimundić
Ana-Maria Šimundić
Short- and long-term stability of synovial fluid calprotectin

14 December 2023 in Sports
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FBFrane Bukvic
Frane Bukvic
AIAlan Ivković
Alan Ivković
HČHelena Čičak
Helena Čičak
LDLora Dukić
Lora Dukić
AŠAna-Maria Šimundić
Ana-Maria Šimundić
DPDaria Pašalić
Daria Pašalić
The objective was to determine the associations between several biochemical indicators and the dynamics of concentration change across four physical fitness phases over the period of a competitive season. Furthermore, associations between serum calprotectin and biomarkers of inflammation or muscle injury and physical indicators were examined. Subjects and methods: Twenty professional male water polo players (median age: 28 (22–42)) were included in this study. Serum creatine kinase activity was determined by the automated photometric UV method. The concentrations of calprotectin, C-reactive protein, and myoglobin were measured using an automated immunoturbidimetric method, while an automated immunochemistry method was employed for interleukin-6, troponin I, and cortisol determination. Tests of repeated strength, maximal strength, and static strength were used to evaluate physical activity. Results: Serum calprotectin concentrations expressed in median and IQR were significantly different: T1: 2.92 g/mL (2.47; 3.86); T2: 2.35 g/mL (1.26; 2.87); T3: 2.27 g/mL (1.60; 3.27); and T4: 1.47 g/mL (1.04; 2.85) (p = 0.004). Cortisol concentration and CK activity showed significant changes among phases (p = 0.049 and p = 0.014, respectively). Each physical activity examined showed a significant seasonal decrease (all p values were 0.001). Calprotectin serum concentration and indicators of muscular injury, inflammation, and physical activity were found to be correlated during particular stages of the seasonal examination. Conclusions: Calprotectin values determined throughout one competitive season decreased as training intensity among water polo players increased. Serum calprotectin concentrations and indicators were related to biochemical markers of inflammation and muscle damage.

15 February 2022 in Biochemia Medica
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HČHelena Čičak
Helena Čičak
DBDanijela Bejuk
Danijela Bejuk
VBVanja Radisic Biljak
Vanja Radisic Biljak
AŠAna-Maria Šimundić
Ana-Maria Šimundić
ANAna Nikler
Ana Nikler
The aims of study were to assess: 1) performance specifications of Atellica 1500, 2) comparability of Atellica 1500 and Iris, 3) the accuracy of both analysers in their ability to detect bacteria. Carryover, linearity, precision, reproducibility, and limit of blank (LoB) verification were evaluated for erythrocyte and leukocyte counts. ICSH 2014 protocol was used for estimation of carryover, CLSI EP15-A3 for precision, and CLSI EP17 for LoB verification. Comparison for quantitative parameters was evaluated by Bland-Altman plot and Passing-Bablok regression. Qualitative parameters were evaluated by Weighted kappa analysis. Sixty-five urine samples were randomly selected and sent for urine culture which was used as reference method to determine the accuracy of bacteria detection by analysers. Analytical specifications of Atellica 1500 were successfully verified. Total of 393 samples were used for qualitative comparison, while 269 for sediment urinalysis. Bland-Altman analysis showed statistically significant proportional bias for erythrocytes and leukocytes. Passing-Bablok analysis for leukocytes pointed to significant constant and minor proportional difference, while it was not performed for erythrocytes due to significant data deviation from linearity. Kappa analysis resulted in the strongest agreements for pH, ketones, glucose concentrations and leukocytes, while the poorest agreement for bacteria. The sensitivity and specificity of bacteria detection were: 91 (59-100)% and 76 (66-87)% for Atellica 1500 and 46 (17-77)% and 96 (87-100)% for Iris. There are large differences between Atellica 1500 and Iris analysers, due to which they are not comparable and can not be used interchangeably. While there was no difference in specificity of bacteria detection, Iris analyser had greater sensitivity.

11 September 2024 in Diagnostics
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FBFrane Bukvic
Frane Bukvic
DMDomagoj Marijančević
Domagoj Marijančević
HČHelena Čičak
Helena Čičak
AŠAna-Maria Šimundić
Ana-Maria Šimundić
DPDaria Pašalić
Daria Pašalić
LDLora Dukić
Lora Dukić
AIM: Our goal was to examine the effect of high-intensity physical activity on changes in the lipid profile, complete blood count (CBC), iron metabolism, and kidney and liver function tests of professional water polo players. METHODS: This study included twenty professional male water polo players. Blood sampling was carried out at the beginning of the season and during periods of high-intensity training. CBCs were determined with a Siemens Advia 2120i hematology analyzer. A Beckman CoulterAU680 chemistry analyzer was used to determine the serum concentrations/activities of lipid profiles and liver and kidney function test analytes. The lipid athlete scores were also determined. RESULTS: The mean corpuscular volume (p = 0.006), platelet count (p = 0.008), and mean platelet volume (p < 0.001) significantly decreased during the high-intensity period, compared with the beginning of the season. The total iron-binding capacity increased (p = 0.001), and ferritin concentrations significantly declined (p = 0.017). The lipid profiles revealed a significant difference between phases, with slight increases in serum total (p = 0.025) and LDL cholesterol (p = 0.002) levels and a decrease in triglyceride concentrations (p = 0.040) in the high-intensity period. During the high-intensity period, the liver and kidney function tests showed a substantial positive effect on lactate dehydrogenase levels (p < 0.001), aspartate aminotransferase (p = 0.028) serum activity, and total protein concentrations (p = 0.033), compared with the beginning of the season. CONCLUSIONS: Water polo players might exhibit a decrease in some CBC parameters, an increase in LDL cholesterol, and a decrease in liver function biomarkers due to intense training at the peak of the competitive season. Kidney function biomarkers remain unchanged.