Publications by authors named "Jurica Maraković"

13 Publications

  • Page 1 of 1

HbA1c in patients with intracranial meningiomas WHO grades I and II: A preliminary study.

IUBMB Life 2020 07 5;72(7):1426-1432. Epub 2020 Mar 5.

Department of Neurosurgery, Clinical Hospital Dubrava, Zagreb, Croatia.

Meningiomas are among the most common primary brain tumors. There is a growing need for novel ways of differentiating between benign (World Health Organization [WHO] grade I) and atypical (WHO grade II) meningiomas as well as for novel markers of the tumor's future behavior. A difference between glucose metabolism in atypical and benign meningiomas is well known. However, a significant correlation between the systemic metabolic status of the patient and the meningioma WHO grade has not yet been established. Our aim was to compare the WHO grades of intracranial meningiomas with the patient's HbA1c levels as a more reliable marker of the chronic systemic metabolic status than the fasting blood glucose value, which is usually looked at. We retrospectively analyzed 15 patients and compared their meningioma WHO grade with their preoperative HbA1c values. Our results show that patients with benign intracranial meningiomas have significantly lower HbA1c value. Conversely, patients with atypical intracranial meningiomas have higher HbA1c values. Furthermore, we showed that the proliferation factor Ki67 was statistically strongly correlated with the HbA1c value (p < .001. These results imply a possible positive correlation between meningioma cell proliferation and the chronic systemic glycemia. Further research in this area could not only lead to better understanding of meningiomas but could have significant clinical application.
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http://dx.doi.org/10.1002/iub.2268DOI Listing
July 2020

Dynamics of inflammatory factors expression in ischemic brain tissue injury.

Neurol Int 2019 Nov 2;11(4):8282. Epub 2019 Dec 2.

Department of Neurosurgery, University Hospital Dubrava, Zagreb.

Ischemic stroke is one of the most common cause of mortality and disability in the modern world. Still, therapeutic options remain modest. Aim of the study was to present dynamics of inflammatory factors expression (C reactive protein, procalcitonin, interleukin 10) in patients after ischemic stroke. Our study included 101 patients divided in thrombolised and nonthrombolised groups. Inflammatory factors concentration in serum was determinate at admission, 24, 48 hours and seven days after the initial onset, while neurological assessment was measured at the admission, 24 hours, seven days and three months after the initial onset using National Institute of Health Stroke Scale and Rankin Scale. Certain pattern was observed in dynamics of inflammatory factors: intensive increase in first and second day after the stroke, followed by decrease till day seven in both groups. Additionally, thrombolised group showed significant neurological improvement. Although well investigated, the role of inflammatory factors in the ischemic stroke still stays controversial. High association of C reactive protein and interleukin 10 values suggest potential prognostic role in patient's follow-up, while the role of procalcitonin values still remains unclear.
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http://dx.doi.org/10.4081/ni.2019.8282DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6908952PMC
November 2019

New Insight into the Mechanism of Mannitol Effects on Cerebrospinal Fluid Pressure Decrease and Craniospinal Fluid Redistribution.

Neuroscience 2018 11 29;392:164-171. Epub 2018 Sep 29.

Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia. Electronic address:

Intracranial hypertension, which often follows a severe brain injury, is usually treated with intravenous (i.v.) application of hyperosmolar solutions. The mechanism of intracranial cerebrospinal fluid (CSF) pressure decrease after such a treatment is still unclear. The aim of this article was to try to explain the mechanism of CSF pressure reduction after i.v. hyperosmolar mannitol bolus in regard to the changes in CSF volume. Two types of experiments were done on anesthetized cats before and after hyperosmolar mannitol application: ventriculo-cisternal perfusion at different perfusion rates, simultaneously measuring the perfusate outflow volume, and CSF pressure recording in the lateral ventricle before and during artificial CSF infusion. Mannitol application in the first group of cats significantly reduced collected prefusate volume during ventriculo-cisternal perfusion, and in the second group it prevented CSF pressure increase caused by artificial CSF infusion. Our results strongly suggest that the mechanism of hyperosmolar mannitol action after its i.v. application is based on osmotic fluid retrieval from interstitial and cerebrospinal compartments into the microvessels. This shift, without significant volume change inside the cranium, causes a predominant decrease of CSF volume in the spinal part of the system, which in turn leads to lowering of the CSF pressure. Spinal CSF volume decrease is enabled by the extensibility of the spinal dura, this way providing the possibility for CSF volume redistribution inside the CSF system, together with CSF pressure decrease. This mechanism of mannitol action is in accordance with the new hypothesis of CSF physiology.
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http://dx.doi.org/10.1016/j.neuroscience.2018.09.029DOI Listing
November 2018

Intraspinal calcinosis mimicking intervertebral disc extrusion: A clinical and surgical case report.

Surg Neurol Int 2018 14;9:166. Epub 2018 Aug 14.

Department of Neurosurgery, Dubrava University Hospital, Zagreb, Croatia.

Background: Subcutaneous calcinosis is a well-recognized manifestation of systemic sclerosis that usually involves multiple pressure points and may also be found in the paraspinal or intraspinal regions. In this case, intraspinal calcinosis uniquely led to a severe neurological deficit.

Case Description: A patient with severe systemic sclerosis/calcinosis exhibited left greater than right lower extremity radiculopathy attributed to intraspinal left-sided L4-L5 calcinosis. On examination, the patient exhibited bilateral positive Lasegue signs, distal lower extremity weakness (left greater than right), and bilaterally decreased Achilles responses. When the magnetic resonance imaging (MRI) revealed a significant intracanalicular mass on the left side at the L4-L5 level, the patient underwent a left-sided L4-L5 decompressive laminectomy. The MRI scan 5 years later revealed no recurrence of the calcinosis, and the patient had no residual neurological deficit.

Conclusions: Spinal calcinosis rarely involves the lumbar spinal canal. Here, a patient with a large left-sided L4-L5 focus of intraspinal calcinosis, mimicking a disc herniation, required a laminectomy to resect the lesion. Lumbar calcinosis should be radiologically evaluated utilizing using X-ray, MRI, and computed tomography studies to adequately document the pathology. Patients, when symptomatic, may require surgical decompression and excision of these lesions.
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http://dx.doi.org/10.4103/sni.sni_147_18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6108162PMC
August 2018

Monoamine Neurotransmitter Metabolite Concentration as a Marker of Cerebrospinal Fluid Volume Changes.

Acta Neurochir Suppl 2016 ;122:283-6

Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia.

Objective: In our previous papers we demonstrated that changes in blood and cerebrospinal fluid (CSF) osmolarity have a strong influence on CSF pressure and volume, which is in accordance with a new proposed hypothesis of CSF physiology. Thus, acute changes in CSF volume should be reflected in the CSF concentration of different central nervous system (CNS) metabolites.

Methods: In anesthetized cats (n = 4) we measured the outflow volume of CSF by cisternal free drainage at a negative CSF pressure (-10 cmH2O) before and after the intraperitoneal (i.p.) application of a hypo-osmolar substance (distilled water). In samples of CSF collected at different time intervals (30 min) we measured the concentration of homovanillic acid (HVA).

Results: In spite of fact that constant CSF outflow volume was obtained after a 30-min period in our model, the concentration of HVA gradually increased over time and became stable after 90 min. After the i.p. application of distilled water the outflow CSF volume increased significantly, whereas the concentration of HVA significantly decreased over 30 min.

Conclusions: The results observed suggest that alterations in serum osmolarity change the CSF volume and concentrations of neurotransmitter metabolites because of the osmotic arrival of water from CNS blood capillaries in all CSF compartments.
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http://dx.doi.org/10.1007/978-3-319-22533-3_56DOI Listing
July 2017

Dependence of cerebrospinal fluid pressure and volume on the changes in serum osmolarity in cats.

Acta Neurochir Suppl 2012 ;114:351-5

Department of Pharmacology, University of Zagreb School of Medicine, Zagreb, Croatia.

Objectives: To study the effect of blood osmolarity on cerebrospinal fluid (CSF) volume and CSF pressure in cats.

Methods: Three types of methods were used on anesthetized cats. The first, ventriculo-cisternal perfusion (12.96 μL/min) before and after i.v. application of 20% mannitol; the second, measuring the outflow of CSF by cisternal free drainage; and the third, measuring CSF pressure in the ventricles of an intact CSF system, with the second and third method being performed before and after the i.p. application of a hypo-osmolar substance (distilled water).

Results: In the first group, the application of 20% mannitol led to a significantly reduced (p < 0.005) outflow volume (from 12.60 ± 0.29 to 0.94 ± 0.09 μL/min). In the second group, the outflow CSF volume significantly increased (p < 0.001) after the application of distilled water (from 18.8 ± 0.3 to 28.2 ± 0.7 μL/min). In the third group, after the application of distilled water, the CSF pressure also significantly increased (p < 0.05; from 8.3 ± 0.8 to 16.1 ± 0.14 cm H(2)O).

Conclusion: We conclude that changes in serum osmolarity change the CSF volume because of the osmotic gradient between the blood and all of the CSF compartments, and also that the change in CSF pressure is closely associated with changes in CSF volume.
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http://dx.doi.org/10.1007/978-3-7091-0956-4_68DOI Listing
May 2012

Potential error in ventriculocisternal perfusion method for determination of cerebrospinal fluid formation rate in cats.

Coll Antropol 2011 Jan;35 Suppl 1:73-7

University of Zagreb, Dubrava University Hospital, Department of Neurosurgery, Zagreb, Croatia.

The cerebrospinal fluid (CSF) formation rate (Vf) has been extensively studied by the ventriculocisternal perfusion, a method still regarded as the most precise one. This method as well as the equation for the calculation of the CSF formation rate (Vf) was established by Heisey et al on indicator dilution in perfusate. They assumed that the dilution of the indicator substance in perfusion is a consequence of newly formed CSF i.e. a higher CSF formation rate would result in a higher degree of dilution of the indicator substance. Therefore, such method is indirect and any mistake in the interpretation of the degree of indicator dilution would lead to questionable and often contradictory results regarding CSF formation rates. According to Heisey's equation, Vf shoud not depend on the rate of ventriculocisternal perfusion. However it has been shown that Vf is perfusion dependt value, and also that during perfusion the indicator substance is partially absorbed into surrounding tissue. It is possible that obtained Vf dependence on perfusion rate was caused by observed absorption of indicator substances. For that reason, in anaesthetised cats ventriculocisternal perfusion was performed at higher (252.0 microL/min) and at lower perfusion rate (65.5 microL/min) and Vf was calculated at both experimental and corrected (just for absorbed amount) values of indicator substance. Since (inspite of the correction) the difference of 12.4 microL/min between lower (15.0 microL/min) and higher perfusion rate (27.4 microL/min) was obtained, it is obvious that ventriculocisternal perfusion method cannot be considered reliable for measuring CSF formation rate.
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January 2011

Effect of osmolarity on CSF volume during ventriculo-aqueductal and ventriculo-cisternal perfusions in cats.

Neurosci Lett 2010 Oct 30;484(2):93-7. Epub 2010 Jul 30.

Department of Neurosurgery, Dubrava University Hospital, Avenija G. Suska 6, 10000 Zagreb, Croatia.

The effect of cerebrospinal fluid (CSF) osmolarity on the CSF volume has been studied on different CSF/brain tissue contact areas. It has been shown, on anesthetized cats under normal CSF pressure, that the perfusion of CSF system (12.96 μl/min) by hyperosmolar CSF (400 mOsml/l) leads to significantly higher outflow volume (μl/min) during ventriculo-cisternal perfusion (29.36 ± 1.17 and 33.50 ± 2.78) than the ventriculo-aqueductal perfusion (19.58 ± 1.57 and 22.10 ± 2.31) in experimental period of 30 or 60 min. Both of these hyperosmolar perfusions resulted in significantly higher outflow volume than the perfusions by isoosmolar artificial CSF (12.86 ± 0.96 and 13.58 ± 1.64). These results suggest that the volume of the CSF depends on both the CSF osmolarity and the size of the contact area between CSF system and surrounding tissue exposed to hyperosmolar CSF. However, all of these facts imply that the control of the CSF volume is not in accordance with the classical hypothesis of cerebrospinal fluid hydrodynamic. According to this hypothesis, the CSF volume should be regulated by active formation of CSF (secretion) inside the brain ventricles and passive CSF absorption outside of the brain. Obtained results correspond to the new hypothesis which claims that the volume of CSF depends on the gradients of hydrostatic and osmotic forces between the blood on one side and extracellular fluid and CSF on the other. The CSF exchange between the entire CSF system and the surrounding tissue should, therefore, be determined by (patho)physiological conditions that predominate within those compartments.
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http://dx.doi.org/10.1016/j.neulet.2010.07.058DOI Listing
October 2010

Fluid perfusion as a method of cerebrospinal fluid formation rate--critical appraisal.

Coll Antropol 2008 Jan;32 Suppl 1:133-7

Laboratory of Neurochemistry and Molecular Neurobiology, Department of Molecular Biology, Ruder Boskovic Institute, Zagreb, Croatia.

The aim of the study was to evaluate whether or not cerebrospinal fluid formation rate (Vf) calculated according to the equation of Heisey et al., truly show the produced cerebrospinal fluid. For this reason Vf was simulated (40.6 microL/min) by an infusion pump in a plastic cylinder and the evaluation was done by comparing the results obtained between the calculated Vf and the simulated one. In both cases the result should be the same (40.6 micro/min). Other types of experiments were carried out by ventriculocisternal perfusion (92.4 microL/min) on anaesthetized and sacrificed cats. If the equation is correct, the calculated Vf for sacrificed animals should be zero, because there is no Vf in dead animals. The fact that the calculated Vf (46.5 microL/min) in the plastic cylinder was different (p < 0.0001) from the simulated one (40.6 microL/min) and that Vf was calculated even for dead animals (3-5 microL/min) clearly shows the that perfusion method may not be an accurate method for determination of Vf.
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January 2008

Intracranial recurrence and distant metastasis of scalp dermatofibrosarcoma protuberans.

J Neurooncol 2008 Jul 15;88(3):305-8. Epub 2008 Mar 15.

Department of Neurosurgery, University hospital Dubrava, Av. G. Suska 6, Zagreb, Croatia.

Only few cases of scalp dermatofibrosarcoma protuberans with intracranial and distant metastasis have been reported. Here we report a case of scalp dermatofibrosarcoma protuberans with frequent local recurrence, intracranial invasion and with distant lung metastasis during 6 years of treatment. We would like to emphasize difficulties in surgical treatment of such invasive and locally recurrent tumors of scalp, and necessity to understand new molecular pathogenesis of dermatofibrosarcoma protuberans and potential treatment strategy with imatinib for patients with surgically untreatable disease. Close surveillance of patients with scalp dermatofibrosarcoma is necessary due recurrence nature of tumor.
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http://dx.doi.org/10.1007/s11060-008-9567-8DOI Listing
July 2008

Effect of head position on cerebrospinal fluid pressure in cats: comparison with artificial model.

Croat Med J 2006 Apr;47(2):233-8

Department of Pharmacology, Zagreb University School of Medicine, Zagreb, Croatia.

Aim: To demonstrate that changes in the cerebrospinal fluid (CSF) pressure in the cranial cavity and spinal canal after head elevation from the horizontal level occur primarily due to the biophysical characteristics of the CSF system, ie, distensibility of the spinal dura.

Methods: Experiments in vivo were performed on cats and a new artificial model of the CSF system with dimensions similar to the CSF system in cats, consisting of non-distensible cranial and distensible spinal part. Measurements of the CSF pressure in the cranial and spinal spaces were performed in chloralose-anesthetized cats (n = 10) in the horizontal position on the base of a stereotaxic apparatus (reference zero point) and in the position in which the head was elevated to 5 cm and 10 cm above that horizontal position. Changes in the CSF pressure in the cranial and spinal part of the model were measured in the cranial part positioned in the same way as the head in cats (n = 5).

Results: When the cat was in the horizontal position, the values of the CSF pressure in the cranial (11.9 +/- 1.1 cm H2O) and spinal (11.8 +/- 0.6 cm H2O) space were not significantly different. When the head was elevated 5 cm or 10 cm above the reference zero point, the CSF pressure in the cranium significantly decreased to 7.7 +/- 0.6 cm H2O and 4.7 +/- 0.7 cm H2O, respectively, while the CSF pressure in the spinal space significantly increased to 13.8 +/- 0.7 cm H2O and 18.5 +/- 1.6 cm H2O, respectively (P<0.001 for both). When the artificial CSF model was positioned in the horizontal level and its cranial part elevated by 5 cm and 10 cm, the changes in the pressure were the same as those in the cats when in the same hydrostatic position.

Conclusions: The new model of the CSF system used in our study faithfully mimicked the changes in the CSF pressure in cats during head elevation in relation to the body. Changes in the pressure in the model were not accompanied by the changes in fluid volume in the non-distensible cranial part of the model. Thus, it seems that the changes in the CSF pressure occur due to the biophysical characteristics of the CSF system rather than the displacement of the blood and CSF volumes from the cranium to the lower part of body.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2080413PMC
April 2006

Evaluation of ventriculo-cisternal perfusion model as a method to study cerebrospinal fluid formation.

Croat Med J 2003 Apr;44(2):161-4

Department of Pharmacology, Zagreb University School of Medicine, Zagreb, Croatia.

Aim: To evaluate ventriculo-cisternal perfusion as a method for measuring cerebrospinal fluid formation rate, calculated by means of the Heisey et al equation. Method. All experiments were carried out on anesthetized domestic cats fixed in the sphinx position in a stereotaxic frame. Ventriculo-cisternal perfusion was used at an intracranial pressure of -10 cm H2O at different perfusion rates (32.0, 65.5, 125.0, and 252.0 microL/min). Dextran blue was applied as an indicator substance and the concentration of the indicator was measured with a spectrophotometer at a wavelength of 635 nm. Cerebrospinal fluid formation rate was calculated with the equation of Heisey et al. Results. The indicator substance was less diluted at a higher perfusion rate, and the calculated cerebrospinal fluid formation rate was lower. The increase in perfusion rate from 65.5 to 125.0 to 252.0 microL/min increased the concentration of indicator substance from 0.75 to 0.89 to 0.97 mg/mL and decreased calculated cerebrospinal fluid formation rate from 21.8 to 15.4 to 7.8 microL/min. This reduction was linear and an increase in the perfusion rate by 1.0 microL/min decreased the cerebrospinal formation rate by 0.05 microL/min. Conclusion. The calculated cerebrospinal fluid formation rate depends on different perfusion rates. The increase in the perfusion rate diminishes the calculated formation rate. Ventriculo-cisternal perfusion may not be a suitable method to calculate the cerebrospinal fluid formation rate according to the equation of Heisey et al.
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April 2003

Surgical treatment of mediastinal parathyroid adenoma.

Acta Med Croatica 2002 ;56(2):65-8

Division of Cardiac Surgery, Department of Surgery, Division of Anesthesiology and Intensive Care of Cardiac Surgery, Dubrava University Hospital, Avenija Gojka Suska 6, 10000 Zagreb, Croatia.

Ectopic parathyroid adenoma is a frequent cause of persistent or recurrent hyperparathyroidism after parathyroidectomy in patients with chronic renal failure on dialysis. An unusual anatomic localization of parathyroid adenoma may make the diagnosis and surgery difficult. In a 41-year-old woman with chronic renal failure, increased serum level of parathyroid hormone and symptoms of progressive renal osteodystrophy, mediastinal parathyroid adenoma was detected in the aorticopulmonary window by 99m Tc sesta MIBI scintigraphy and transmission computed tomography. Extirpation of adenoma, sized 3 x 2 cm, was performed through a left thoracotomy. Serum parathormone level returned to normal and the patient steadily recovered.
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March 2003