Center for Medical Biochemistry

Belgrade, Serbia

Center for Medical Biochemistry

Belgrade, Serbia
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Milanovic Z.,University of Belgrade | Ilic A.,University of Belgrade | Andric J.F.,University of Belgrade | Beletic A.,Center for Medical Biochemistry | Filipovic M.K.,University of Belgrade
Ticks and Tick-borne Diseases | Year: 2017

Babesia canis and Dirofilaria immitis are emerging and geographically overlapping vector-borne pathogens in dogs. Infection with B. canis leads to acute-phase response (APR) that can be mild to severe and results in either non-complicated or complicated forms of the disease. The aim of this study was to determine whether acute B. canis infection is more severe in dogs with underlying asymptomatic D. immitis infection. Dogs of both sexes, different ages and breeds, with naturally occurring mono-infections with B. canis (n = 13) and D. immitis (n = 18) and co-infected dogs (n = 7) were enrolled as well as healthy controls (n = 15). Routine haematology and biochemistry, agarose gel electrophoresis (agEF) protein fraction separation and enzyme-linked immunosorbent assay (ELISA) for serum amyloid A (SAA) were performed. Based on clinical and laboratory findings, sepsis was diagnosed in the majority of dogs with acute B. canis infection with or without underlying asymptomatic D. immitis infection. Overall, haematology, biochemistry and agEF pattern changes were induced and dictated by acute B. canis infection whether or not the dogs had an asymptomatic D. immitis infection. D. immitis infection slightly influenced the level of anaemia, slightly aggravated the level of dehydration and increased the concentration of γ-globulins in acute-phase B. canis infection. D. immitis infection prevented B. canis-induced leukopenia. SAA equally increased in dogs with acute B. canis infection with or without underlying D. immitis infection. The level of SAA was not changed in dogs with asymptomatic D. immitis when compared to the controls. In conclusion, asymptomatic D. immitis infection does not influence overall APR after acute B. canis infection. © 2017 Elsevier GmbH.


Vodnik T.,Center for Medical Biochemistry | Tadic T.,Center for Medical Biochemistry | Majkic-Singh N.,University of Belgrade
Clinical Chemistry and Laboratory Medicine | Year: 2013

Background: The aim of the study was to identify the diagnostic significance of presepsin in acute abdominal conditions and also to examine the correlation between presepsin, procalcitonin (PCT) and other parameters. Methods: To detect presepsin we used a new rapid method based on a chemiluminescent enzyme immunoassay. The clinical usefulness of presepsin to differentiate bacterial and non-bacterial infection [including systemic inflammation response syndrome (SIRS)] was studied and compared with PCT, C-reactive protein (CRP) and white blood cells (WBC). Results: The presepsin values in different conditions were (mean ± standard deviation): healthy group (n = 70) 258.7 ± 92.53 pg/mL; SIRS (n = 30) 430.0 ± 141.33 pg/mL; sepsis (n = 30) 1508.3 ± 866.6 pg/mL. The presepsin values were significantly higher in patients with sepsis than the SIRS group (p < 0.0001, Mann-Whitney U-test). The area under the receiver operating characteristics (ROC) curve (AUC) for discriminating of the SIRS from the sepsis patients was 0.996 for presepsin and it was greater than the AUC of PCT (0.912), CRP (0.857) or WBC (0.777). Conclusions: The ROC curve of the SIRS patient without infection and the sepsis patient showed that the presepsin concentration was a significantly sensitive indicator of sepsis and useful marker for the rapid diagnosis of sepsis.


Vasiljevic-Pokrajcic Z.,University of Belgrade | Marinkovic J.,Institute for Medical Statistics and Informatics | Vukcevic V.,University of Belgrade | Stefanovic B.,University of Belgrade | And 3 more authors.
JACC: Cardiovascular Interventions | Year: 2016

Objectives This study aimed to assess the clinical impact of immediate versus delayed invasive intervention in patients with non-ST-segment myocardial infarction (NSTEMI). Background Previous studies found conflicting results on the effects of earlier invasive intervention in a heterogeneous population of acute coronary syndromes without ST-segment elevation. Methods We randomized 323 NSTEMI patients to an immediate-intervention group (<2 h after randomization, n = 162) and a delayed-intervention group (2 to 72 h, n = 161).The primary endpoint was the occurrence of death or new myocardial infarction (MI) at 30-day follow-up. Results Median time from randomization to angiography was 1.4 h and 61.0 h in the immediate-intervention group and the delayed-intervention group, respectively (p < 0.001). At 30 days, the primary endpoint was achieved less frequently in patients undergoing immediate intervention (4.3% vs. 13%, hazard ratio: 0.32, 95% confidence interval: 0.13 to 0.74; p = 0.008). At 1 year, this difference persisted (6.8% in the immediate-intervention group vs. 18.8% in delayed-intervention group; hazard ratio: 0.34, 95% confidence interval: 0.17 to 0.67; p = 0.002). The observed results were mainly attributable to the occurrence of new MI in the pre-catheterization period (0 deaths + 0 MIs in the immediate-intervention group vs. 1 death + 10 MIs in the delayed-intervention group). The rate of deaths, new MI, or recurrent ischemia was lower in the immediate-intervention group at both 30 days (6.8% vs. 26.7%; p < 0.001) and 1 year (15.4% vs. 33.1%; p < 0.001). Conclusions Immediate invasive strategy in NSTEMI patients is associated with lower rates of death or new MI compared with the delayed invasive strategy at early and midterm follow-up, mainly due to a decrease in the risk of new MI in the pre-catheterization period. (Immediate Versus Delayed Invasive Intervention for Non-STEMI Patients [RIDDLE-NSTEMI]; NCT02419833) © 2016 by the American College of Cardiology Foundation.


Simundic A.-M.,University of Zagreb | Cornes M.,Hospitals NHS Trust | Grankvist K.,Umeå University | Lippi G.,Academic Hospital of Parma | And 5 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2013

Background: European questionnaire survey was conducted by the European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase (EFLM WG-PA) to assess how phlebotomy is performed in EFLM countries, including differences in personnel, level of education and skills, and to investigate the presence and compliance of national phlebotomy guidelines on this matter. Methods: A questionnaire was constructed containing questions elucidating different aspects of the organization behind the phlebotomy praxis on a national basis, including questions on the staff performing phlebotomy, the education of these staff members, and the existence of and adherence to national guidelines. All 39 EFLM member countries were invited to participate. Results: In total 28/39 (72%) EFLM member countries responded. Seven out of the 28 (25%) have national phlebotomy guidelines and five have implemented other guidelines. The estimated compliance with phlebotomy guidance for the laboratories in the countries that have national guidelines available is poor, regardless to whether the phlebotomy was under the laboratory control or not. Most countries were interested in EFLM guidelines and to participate in a pilot EFLM preanalytical phase external quality assessment (EQA) scheme. In the responding EFLM member countries, the majority of phlebotomy is performed by nurses and laboratory technicians. Their basic education is generally 4-5 years of high school, followed by 2-5 years of colleague or university studies. Only a third (10/28; 36%) of the participating member countries has any specific training available as a continuous educational resource. A specific training for phlebotomy is not part of the education required to become qualified in 6/28 (21%) and 9/28 (32%) of countries for nurses and laboratory technicians, respectively. In countries and professions where training is required, most require more than 5 h of training. Conclusions: Based on the results of this survey we conclude the following: 1) There is a need to assess the quality of current practices, compliance to the CLSI H3-A6 guidelines and to identify some most critical steps which occur during phlebotomy, in different healthcare settings, across Europe; 2) Existing CLSI H3-A6 phlebotomy guidelines should be adapted and used locally in all European countries which do not have their own guidelines; 3) National EFLM societies need to be engaged in basic training program development and continuous education of healthcare phlebotomy staff (implementing the certification of competence). © 2013 by Walter de Gruyter Berlin Boston 2013.


Jovicic S.,Center for Medical Biochemistry | Ignjatovic S.,University of Belgrade | Majkic-Singh N.,University of Belgrade
Journal of Medical Biochemistry | Year: 2012

Vitamin D is not technically a vitamin, since it is not an essential dietary factor. It is rather a prohormone produced photochemically in the skin from 7-dehydrocholesterol. Vitamin D and its metabolites may be categorized as either cholecalciferols or ergocalciferols. Cholecalciferol (vi - tamin D3) is the parent compound of the naturally occurring family and is produced in the skin from 7-dehydrocholesterol on exposure to the ultraviolet B portion of sunlight. Vitamin D2 (ergocalciferol), the parent compound of the other family, is manufactured by irradiation of ergosterol produced by yeasts and its potency is less than one-third of vitamin D3's potency. The steps in the vitamin D endocrine system include the following: 1) the photoconversion of 7- dehydrocholesterol to vitamin D3 in the skin or dietary intake of vitamin D3; 2) metabolism of vitamin D3 by the liver to 25-hydroxyvitamin-D3 [25(OH)D3 ], the major form of vitamin D circulating in the blood compartment; 3) conversion of 25(OH)D3 by the kidney (functioning as an endocrine gland) to the hormone 1,25-dihydroxyvitamin D3 [1,25(OH)2D3 ]; 4) systemic transport of the dihydroxylated metabolite 1,25(OH)2D3 to distal target organs; and 5) binding of 1,25(OH)2D3 to a nuclear receptor (VDR) at target organs, followed by generation of appropriate biological responses. The activation of vitamin D to its hormonal form is mediated by cytochrome P450 enzymes. Six cytochrome P450 (CYP) isoforms have been shown to hydroxylate vitamin D. Four of these, CYP27A1, CYP2R1, CYP3A4 and CYP2J3, are candidates for the enzyme vitamin D 25-hy - droxylase that is involved in the first step of activation. The highly regulated, renal enzyme 25-hydroxyvitamin D-1a-hy - dro xylase contains the component CYP27B1, which completes the activation pathway to the hormonal form 1,25(OH)2D3. A five-step inactivation pathway from 1,25(OH)2D3 to calcitroic acid is attributed to a single multifunctional CYP, CYP24A1, which is transcriptionally in du - ced in vitamin D target cells by the action of 1,25(OH)2D3. An additional key component in the operation of the vitamin D endocrine system is the plasma vitamin D binding protein (DBP), which carries vitamin D3 and its metabolites to their metabolism and target organs. DBP is a specific, high-affinity transport protein. It is synthesized by the liver and circulates in great excess, with fewer than 5% of the binding sites normally occupied. 1,25(OH)2D3, acts as a ligand for a nuclear transcription factor, vitamin D receptor - VDR, which like all other nuclear receptors, regulates gene transcription and cell function. The widespread presence of VDR, and the key activating (1a-hydroxylase, CYP27B1) and inactivating (24-hydroxylase, CYP24A1) en - zy mes in most mammalian cells means that the cells in these tissues have the potential to produce biological res pon ses, depending on the availability of appropriate amounts of vi - tamin D3. Thanks to this widespread presence of elements of vitamin D endocrine system, its biological features are being recognized outside bone tissue, i.e. calcium and pho - sphate metabolism.


PubMed | University of Belgrade, Center for Medical Biochemistry and Society of Medical Biochemists of Serbia
Type: Journal Article | Journal: Laboratory medicine | Year: 2016

The measurement of pancreatic elastase (PE) in feces is used widely to screen for pancreatic exocrine insufficiency. The aim of our study was to evaluate the relationship of PE with residual beta cell secretion and metabolic control in patients with diabetes mellitus.We determined the presence of PE in specimens via enzyme-linked immunosorbent assay (ELISA), whereas serum fasting glucose, C-peptide, amylase, lipase, triglycerides, total 25(OH)-vitamin D, C-reactive protein (CRP), and hemoglobin A1c (HbA1c) concentrations were assayed using routine laboratory tests.PE values in 48 patients with diabetes were significantly lower than in 24 healthy volunteers (P=001). In one-third of participants with diabetes mellitus, PE wereless than 200 g per g, indicating pancreatic functional insufficiency. Among the patients in the cohort, PE correlated positively with C-peptide levels (P=04), lipase (P=009), CRP (P=04), sex (P=03), and BMI (P=02) but not significantly with duration of diabetes (P=81) or levels of HbA1c(P=87), amylase (P=06), total 25(OH)-vitamin D (P=16), or triglycerides (P=52).Our results demonstrated a strong association of diabetes with low PE levels.


Djordjevic B.V.,Institute of Biochemistry | Pavlovic R.,University of Niš | Cosic V.,Center for Medical Biochemistry | Deljanin-Ilic M.,Institute for Cardiovascular and Rheumatic Diseases | And 3 more authors.
Amino Acids | Year: 2012

Elevated plasma concentrations of asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) were found in various clinical settings including coronary heart disease. To assess ADMA and SDMA diagnostic validity in patients with different stages of ischemic heart disease, we studied these markers in patients having stable angina pectoris (SAP), unstable angina (USAP), and acute myocardial infarction (AMI). The results were compared with the values of healthy individuals. Plasma ADMA and SDMA levels were measured by high-performance liquid chromatography. In all patient groups both markers were significantly elevated in comparison with control ones (p\0.001). In SAP patients, the median ADMA value was 0.75 (0.31-2.73) lmol/L, and SDMA 1.11 (0.69-0.1.42) lmol/L, in USAP patients, the marker values were 0.94 (0.34-3.13) lmol/L and 1.23 (0.88-4.72) lmol/L, and in AMI patients, 0.98 (0.48-2.01) lmol/L and 1.26 (0.75-2.93) lmol/L, while in healthy subjects they were 0.31 (0.17-0.87) lmol/L and 0.29 (0.20-0.83) lmol/L, respectively. SDMA was found significantly different in SAP and AMI patients (p\0.05). Diagnostic accuracy was determined by receiver operating characteristic (ROC) curve analysis. The highest area under the ROC (AUC) for ADMA was obtained in AMI patients (0.976), while for SDMA in USAP patients (1.000). There was no significant difference between the AUCs. The greatest sensitivity and specificity were found in the USAP group (95.65 and 96.30 % for ADMA, and 100 % for each characteristic of SDMA). Considering these results, SDMA showed better clinical accuracy in assessing ischemic disease, where it could be used as a valid marker and a therapeutic target. © Springer-Verlag 2012.


Markovic D.,Center for Medical Biochemistry | Dordevic V.,Center for Medical Biochemistry
Journal of Medical Biochemistry | Year: 2013

Apoptosis is a form of cell death which is important in many physiological processes. Four apoptotic mechanisms have been identified but two have been well examined: the intrinsic and the extrinsic mechanism. Due to many pro/antiapoptotic factors, these processes take place on a physiologically useful level. In cases of apoptosis dysregu lation, illnesses occur such as neurodegenerative diseases combined with an increased level of cell death or cancerogenesis associated with uncontrolled cell proliferation. Apoptosis can be triggered by the activation of the first caspase in a series and stopped by its deactivation, which represents a new challenge: determining the point of no return. Besides the antiapoptotic proteins (Bcl 2, Bcl XL), a family of proteins called the Inhibitors of Apoptosis Proteins (IAPs) play a key role in the regulation of apoptosis. Members of the IAP family are: cIAP1, cIAP2, XIAP, Survivin, Livin and TsIAP. Domain BIR is the most important in the IAP structure since it determines their specificity for caspases. The interaction of IAPs with caspases is complex and not completely understood, however, IAPs are considered to be important target proteins in the therapy of tumor and autoimmune diseases.


Koracevic G.,Clinical Center | Cosic V.,Center for Medical Biochemistry | Stojanovic I.,University of Niš
Journal of Medical Biochemistry | Year: 2013

Cardiac troponins have a crucial role in diagnosing acute myocardial infarction, but have been considered by some authors to have a high false positive rate. Such opinions may decrease the confidence in troponin with important clinical consequences. The aim of the paper is to analyze three different meanings of the phrase false positive troponin: A) analytic (technical) false positive, with no real myocardial damage; B) false positive considering AMI: cardiac injury is present, but there is no AMI; C) false positive considering CAD: there is myocardial damage, but no CAD. The most frequent and the most important source of misunderstanding is the confusion between aspects A) and B). Namely, there has been a relatively small percentage of false positive troponin elevations due to analytic reasons. On the contrary, there has been a re - latively large percentage of false positive results in patients with myocardial necrosis due to causes other than AMI; for them - instead of FP troponin elevation - another phrase ought to be used, e.g., non-AMI troponin elevation until the etiopathogenesis in an individual patient is recognized. The phrase false positive troponin should be restricted to the artificial increase in troponin due to preanalytic and analytic reasons. By doing so, we may decrease the degree of confusion about troponin and increase the confidence in this highly specific marker of myocardial injury. The possibility of an analytic false positive result should always be kept in mind when one interprets elevated troponin.


Plebani M.,University of Padua | Astion M.L.,Seattle Children Hospital | Barth J.H.,Leeds Teaching Hospitals NHS Trust | Chen W.,Beijing Hospital | And 9 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2014

Quality indicators (QIs) are fundamental tools for enabling users to quantify the quality of all operational processes by comparing it against a defined criterion. QIs data should be collected over time to identify, correct, and continuously monitor defects and improve performance and patient safety by identifying and implementing effective interventions. According to the international standard for medical laboratories accreditation, the laboratory shall establish and periodically review QIs to monitor and evaluate performance throughout critical aspects of pre-, intra-, and post-analytical processes. However, while some interesting programs on indicators in the total testing process have been developed in some countries, there is no consensus for the production of joint recommendations focusing on the adoption of universal QIs and common terminology in the total testing process. A preliminary agreement has been achieved in a Consensus Conference organized in Padua in 2013, after revising the model of quality indicators (MQI) developed by the Working Group on "Laboratory Errors and Patient Safety" of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). The consensually accepted list of QIs, which takes into consideration both their importance and applicability, should be tested by all potentially interested clinical laboratories to identify further steps in the harmonization project.

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