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Background: Surgical stress and pain result in activation of hypothalamus-pituitary-adrenal axis. The aim of this study was to establish the effects of postoperative pain and various modalities of analgesic administration on salivary and serum cortisol levels, as well as to establish the validity of salivary cortisol as a stress indicator in surgical patients. Methods: A randomized controlled trial involved 60 patients scheduled for elective abdominal aortic aneurysm surgery. Patients were randomly divided into two groups depending on the model of postoperative analgesia. The first group (MI - morphine intermittently) included patients given morphine doses 0.1 mg/kg/6h s.c. intermittently. The second group (MPCA - morphine patient-controlled analgesia) included patients who received morphine via the PCA system - intravenous administration of morphine adjusted to a dose of 1 mg per shot and a lockout interval of 6 minutes. Results: The intensity of pain did not significantly vary until the hour 10 post-surgery. However, in the period from hour 10 to hour 18 post-surgery, higher intensity of pain was reported in group MPCA (P < 0.05). Hemodynamic instability was more prevalent in the MI group (40.0% vs 6.7%, P = 0.0048). Serum cortisol levels were almost identical in both groups (MI 509.4 nmol/L vs MPCA 511.0 nmol/L, P = 0.1473). Higher values of salivary cortisol were recorded in group MPCA; however, the difference was not statistically significant (47.1 nmol/L vs 116.3 nmol/L, P = 0.0970). Conclusion: Our study confirmed that salivary cortisol is a more sensitive stress biomarker in surgical patients as compared to blood cortisol.

Background: The investigation of the prevalence of the IgG and the IgM isotypes of anticardiolipin (aCL) and antib2glycoprotein I (ab2gpI) Abs in healthy Serbian middleaged subjects was the main goal of our study. In addition, we analyzed the potential associations of above-mentioned Abs with serum proteins and lipids/lipoproteins. Methods: Forty healthy subjects were included in our study. Obesity (BMI 30 kg/m2) was present in 8/40 (20%) subjects. Titers of analyzed Abs were measured by ELISA. Results: The prevalence of IgG and IgM ab2gpI Abs was 5% and 12.5%, respectively, while the prevalence of IgM aCL was 10%. The IgG ab2gpI Abs were significantly different between subjects with normal triglycerides levels and those with hypertriglyceridemia (Mann-Whitney, P = 0.014). The significant difference in hsCRP concentrations was observed between subjects with the increased levels of the IgM isotype of aCL Abs and those with normal IgM aCL values (Mann-Whitney, P = 0.028). Conclusions: Dyslipidemia and BMI ≥30 were associated with aPL Abs and therefore, the correction of BMI and lipid status might be beneficial in reduction or elimination of predisposing factors that might trigger thrombotic events in otherwise healthy middle-aged subjects. Larger national study is necessary to confirm our findings.

Background: Some observational studies indicate an association of 25-hydroxy vitamin D (25(OH)D) insufficiency and atherogenic cholesterol concentrations. The aim of this study was to investigate relationship between 25(OH)D concentrations and lipid parameters in end stage renal disease (ESRD) patients, separately for predialysis, hemodialysis and peritoneal dialysis patients. Methods: We have adjusted 25(OH)D concentrations for seasonal variability with cosinor analysis, and performed all further analysis using these corrected 25(OH)D concentrations. Concentrations of 25(OH)D and the lipid parameters were determined in 214 ESRD patients and 50 control group participants. The analysis included the measurement of 25(OH)D by HPLC, apolipoprotein (Apo) AI, ApoB and Lp(a) by nephelometry, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) by spectrophotometry and manually calculated ApoB/ApoAI and LDL-C/HDL-C ratio. Results: ESRD patients with adjusted 25(OH)D concentrations of 50 nmol/L had significantly higher TC (P = 0.005) and ApoAI (P = 0.049). Significantly higher HDLC (P = 0.011) and ApoAI (P = 0.020) were found in hemodialysis patients with the 25(OH)D concentrations of 50 nmol/L. The other analyzed lipid parameters differed significantly between predialysis, hemodialysis and peritoneal dialysis patients with 25(OH)D concentrations of < 50 nmol/L. Conclusions: Our study indicate the significant relationship between 25(OH)D repletion and optimal concentrations of lipid parameters in ESRD patients. Further research is necessary to explain whether joint evaluation of vitamin D status and lipid abnormalities could improve cardiovascular outcome in ESRD patients.

Medical biochemistry is the usual name for clinical biochemistry or clinical chemistry in Serbia, and medical biochemist is the official name for the clinical chemist (or clinical biochemist). This is the largest sub-discipline of the laboratory medicine in Serbia. It includes all aspects of clinical chemistry, and also laboratory hematology with coagulation, immunology, etc. Medical biochemistry laboratories in Serbia and medical biochemists as a profession are part of Health Care System and their activities are regulated through: the Health Care Law and rules issued by the Chamber of Medical Biochemists of Serbia. The first continuous and organized education for Medical Biochemists (Clinical Chemists) in Serbia dates from 1945, when the Department of Medical Biochemistry was established at the Pharmaceutical Faculty in Belgrade. In 1987 at the same Faculty a five years undergraduate study program was established, educating Medical Biochemists under a special program. Since the academic year 2006/2007 the new five year undergraduate (according to Bologna Declaration) and four-year postgraduate program according to EC4 European Syllabus for Postgraduate Training in Clinical Chemistry and Laboratory Medicine has been established. The Ministry of Education and Ministry of Public Health accredited these programs. There are four requirements for practicing medical biochemistry in the Health Care System: University Diploma of the Faculty of Pharmacy (Study of Medical Biochemistry), successful completion of the professional exam at the Ministry of Health after completion of one additional year of obligatory practical training in the medical biochemistry laboratories, membership in the Serbian Chamber of Medical Biochemists and licence for skilled work issued by the Serbian Chamber of Medical Biochemists. In order to present laboratory medical biochemistry practice in Serbia this paper will be focused on the following: Serbian national legislation, healthcare services organization, sub-disciplines of laboratory medicine and medical biochemistry as the most significant, education in medical biochemistry, conditions for professional practice in medical biochemistry, continuous quality improvement, and accreditation. Serbian healthcare is based on fundamental principles of universal health coverage and solidarity between all citizens.

Background: Until now, a proper biomarker(s) to evaluate sarcoidosis activity has not been recognized. The aims of this study were to evaluate the sensitivity and specificity of the two biomarkers of sarcoidosis activity already in use (serum angiotensin converting enzyme - ACE and serum chitotriosidase) in a population of 430 sarcoidosis patients. The activities of these markers were also analyzed in a group of 264 healthy controls. Methods: Four hundred and thirty biopsy positive sarcoidosis patients were divided into groups with active and inactive disease, and groups with acute or chronic disease. In a subgroup of 55 sarcoidosis patients, activity was also assessed by F-18 fluorodeoxyglucose positron emission tomography (18F-FDG-PET) scanning. Both serum chitotriosidase and ACE levels showed non-normal distribution, so nonparametric tests were used in statistical analysis. Results: Serum chitotriosidase activities were almost 6 times higher in patients with active sarcoidosis than in healthy controls and inactive disease. A serum chitotriosidase value of 100 nmol/mL/h had the sensitivity of 82.5% and specificity of 70.0%. A serum ACE activity cutoff value of 32.0 U/L had the sensitivity of 66.0% and the specificity of 54%. A statistically significant correlation was obtained between the focal granulomatous activity detected on 18F-FDG PET/CT and serum chitotriosidase levels, but no such correlation was found with ACE. The levels of serum chitotriosidase activity significantly correlated with the disease duration (P< 0.0001). Also, serum chitotriosidase significantly correlated with clinical outcome status (COS) categories (p = 0.272, P = 0.001). Conclusions: Serum chitotriosidase proved to be a reliable biomarker of sarcoidosis activity and disease chronicity.

Determination of 25-hydroxyvitamin D [25(OH)D] represents a unique challenge, considering its lipophilic nature. Considering the widespread prevalence of vitamin D deficiency, which leads to increasing number of requests for 25(OH)D determination, immunoassay measurements adjusted to automated analyzers are being developed. Because of the variability among assays, it is often difficult to monitor vitamin D status and supplementation. The aim of this study was to compare the results of two immunoassays with high performance liquid chromatography with ultraviolet detection (HPLC-UV). Also, the aim was to estimate vitamin D status, since up to date the prevalence of vitamin D deficiency in Serbia was not examined. We have evaluated analytical characteristics of two automated immunoassays for 25(OH)D determination, from Roche (Cobas® e601) and Abbott (Architect). For comparison studies we used HPLC analysis of 25-(OH)-Vitamin D3/D2 from Chromsystems (Waters isocratic system). In order to estimate vitamin D status in general population, we have searched the database of the laboratory information system and analyzed the data from 533 patients whose 25(OH)D was determined together with intact parathyroid hormone (iPTH). For imprecision assessment, four serum pools were prepared with following 25(OH)D concentrations: 35 nmol/L, ?50 nmol/L, ?75 nmol/L and ?125 nmol/L. Obtai ned CVs for Roche method were 1.5-2.8% for within-run and 4.0-6.7% for between-run imprecision. For Abbott method, CVs were 0.7-4.4% for withinrun and 3.8-7.2% for between-run imprecision. Inaccuracy was analyzed with commercial control sera. Obtained deviations from target value were 2.1% for Roche assay and 1.3-1.5% for Abbott method, and were not statistically significant (P>0.05). Comparison of Roche and HPLC-UV methods using Passing-Bablok regression analysis gave the following equation for the regression line y=0.937x+9.518 (r=0.739; n=97) and the regression line equation from the comparison of Abbott and HPLC-UV methods was y=0.745x+10.343 (r=0.793; n=97). Mean difference and SD for Bland-Altman plot were -4.5 nmol/L and 21.75 nmo/L, respectively for Roche method and 6.4 nmol/L and 18.8 nmol/L, respectively for Abbott. Statistical analysis (Chi-square test) of frequency distribution among different vitamin D status categories (75 nmol/L sufficiency) showed that the frequency distribution obtained with Abbott method was significantly different from the distribution of the HPLC results, in contrast to Roche results frequency distribution which did not differ significantly. Also, statistical analysis of the agreement between the three methods for each vitamin D status category showed that results of both Roche and Abbott methods were significantly higher than HPLC in the two deficiency categories (P=0.005 for Roche, P=0.0407 for Abbott), and in the sufficiency category Abbott method significantly underestimated concentration of 25(OH)D compared to HPLC results (P75 nmol/L).

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 (vitamin 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-hydroxylase that is involved in the first step of activation. The highly regulated, renal enzyme 25-hydroxyvitamin D-1a-hydro 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 induced 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) enzymes in most mammalian cells means that the cells in these tissues have the potential to produce biological responses, depending on the availability of appropriate amounts of vitamin 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 phosphate metabolism.

The Third Report of the expert panel on detection, evaluation and treatment of high blood cholesterol in adults (Adult Treatment Panel III, ATP III) constitutes the National Cholesterol Education Program's (NCEP's) updated clinical guidelines for cholesterol testing and clinical management of patients with high blood cholesterol. While ATP III maintains attention to intensive treatment of patients with coronary heart disease (CHD), its major new feature is a focus on primary prevention in persons with multiple risk factors. ATP III continues to identify elevated LDL cholesterol as the primary target of cholesterol lowering therapy. A basic principle of prevention is that the intensity of risk reduction therapy should be adjusted to a person's absolute risk. Risk assessment requires measurement of LDL cholesterol as part of lipoprotein analysis and identification of accompanying risk determinants (presence or absence of CHD, other clinical forms of atherosclerotic disease, diabetes, cigarette smoking, hypertension, low HDL cholesterol, family history of premature CHD, age). The category of highest risk consists of CHD and CHD risk equivalents - persons with absolute 10-year risk for major coronary events (death and myocardial infarction) >20%. The second category consists of persons with multiple (2+) risk factors in whom 10-year risk for CHD is >-20%. Absolute risk is estimated from Framingham risk scores. The third category consists of persons having 0-1 risk factor. The LDL cholesterol goal for each category is defined and it can be achieved with dietary changes and/or drug therapy. European guidelines on cardiovascular disease (CVD) prevention in clinical practice recommend using the SCORE (Systematic COronary Risk Evaluation) Risk Charts in order to assess the risk for development of CVD, which is defined in terms of the absolute 10 year probability of developing a fatal cardiovascular event. The aim of this paper is to introduce parts of the NCEP's ATP III and European guidelines important for their implementation in laboratory practice.

Numerous studies have shown that the major risk factors for coronary heart disease (cigarette smoking, hypertension, elevated serum total cholesterol and low-density lipoprotein cholesterol - LDL, low serum high-density lipoprotein cholesterol - HDL, diabetes mellitus and advancing age), are additive in predictive power. Accordingly, the total risk of a person can be estimated by summing up the risk imparted by each of the major risk factors. Using data obtained from population studies, various risk assessment algorithms have been developed. The aim of this study was to compare the two most common risk scores. Risk assessment for determining 10-year risk in 185 healthy, asymptomatic individuals of both sexes, 30-85 years old, was carried out according to both Framingham (FRS) and SCORE risk scoring. The risk factors included in the calculation of 10-year risk are gender, age, total cholesterol, HDL-cholesterol, systolic blood pressure, treatment for hypertension and cigarette smoking. The determinations of total cholesterol and HDL-cholesterol were made in sera collected after a 12h fasting period using an Olympus AU2700 automated analyzer. The Framingham risk score was determined using an electronic calculator - ATP III Risk Estimator, and the risk status according to SCORE was obtained using charts for the 10-year risk in populations at high risk. Among 185 participants, in 152 (82%) 10-year risk for Coronary Heart Disease (CHD) death was 20%) according to FRS. According to SCORE, 110 (60%) participants had 5% of 10-year risk for cardiovascular death. Different categories of risk were assigned to ∼30% of individuals according to different risk assessment models. Differences in risk classification when using two different risk assessment algorithms can be explained with several important issues including different endpoints, consideration of interactions and incorporation of antihypertensive use. It is important to note that neither FRS nor SCORE have been appropriately adjusted for our population, according to the national cardiovascular mortality rate.