Risk analysis of the preanalytical process based on quality indicators data.

BACKGROUND: Improving quality and patient safety in the medical biochemistry laboratory accredited according to the International Standard Organization (ISO 15189:2012) requires the patient-centered evaluation of errors based on the implementation of quality indicators (QIs) across the total testing process. Our main goal was to achieve quality improvement of the preanalytical process in an emergency laboratory which had the highest error rate using risk management principles. METHODS: Failure mode and effects analysis (FMEA) was applied to analyze predefined preanalytical QIs and score laboratory failures for the failure demerit value (FDV), probability of failure (PF) and probability of failure remedy (PFR). Based on obtained scores (on a 10-point scale) risk priority numbers (RPNs) were calculated. RESULTS: A total of five failure modes were identified in the preanalytic process. The calculated risks were "sample hemolysis" (RPN, 168),"misidentified samples" (RPN, 108),"samples clotted" (RPN, 90),"sample volume error" (RPN, 72) and "samples transported at inappropriate temperature" (RPN, 24). The activation of corrective risk-reducing measures for failure modes with RPN≥30 resulted in quality improvement with the significant decrease in reevaluated RPNs. CONCLUSIONS: The implementation of a preanalytical quality monitoring system based on observation of evidence-based QIs and patient-centered evaluation of errors through risk analysis with regular tailored education as well as implementing process improvements can effectively reduce preanalytical errors in the emergency laboratory and improve patient safety.

Standardization in laboratory medicine: Adoption of common reference intervals to the Croatian population.

Considering the fact that the results of laboratory tests provide useful information about the state of health of patients, determination of reference value is considered an intrinsic part in the development of laboratory medicine. There are still huge differences in the analytical methods used as well as in the associated reference intervals which could consequently significantly affect the proper assessment of patient health. In a constant effort to increase the quality of patients' care, there are numerous international initiatives for standardization and/or harmonization of laboratory diagnostics in order to achieve maximum comparability of laboratory test results and improve patient safety. Through the standardization and harmonization processes of analytical methods the ability to create unique reference intervals is achieved. Such reference intervals could be applied globally in all laboratories using methods traceable to the same reference measuring system and analysing the biological samples from the populations with similar socio-demographic and ethnic characteristics. In this review we outlined the results of the harmonization processes in Croatia in the field of population based reference intervals for clinically relevant blood and serum constituents which are in accordance with ongoing activity for worldwide standardization and harmonization based on traceability in laboratory medicine.

Heat shock protein 70 and antibodies to heat shock protein 60 are associated with cerebrovascular atherosclerosis.

OBJECTIVES: Heat shock proteins (Hsps) are produced by all cells, including vascular, to ensure stress protection. Damaged cells release Hsps in their local environment and systemic circulation. The aim of this study was to investigate the involvement and prognostic utility of serum Hsp60 and Hsp70, and the respective antibodies anti-Hsp60 and anti-Hsp70 in subjects with advanced atherosclerosis resulting in high degree of cerebrovascular stenosis. DESIGN AND METHODS: Ultrasound Doppler examination of carotid arteries was used to discriminate between control and cerebrovascular atherosclerosis subjects. Twenty eight subjects without carotid obstruction were selected as controls. Fifty patients with obstruction of cerebrovascular blood flow were evaluated for the degree of stenosis of cerebral arteries by digital subtraction angiography. In parallel, serum concentrations of Hsp60, Hsp70, anti-Hsp60 and anti-Hsp70 were measured by ELISA kits. RESULTS: Anti-Hsp60 was significantly higher (P=0.003) in the atherosclerosis group than in the control group (23.62ng/L vs. 15.28ng/L, respectively, expressed as median). Circulating Hsp70 was lower in the atherosclerosis than in the control group (P=0.048), with respective median values of 0.00µg/L vs. 0.22µg/L. Concentrations of Hsp60 and anti-Hsp70 did not differ significantly between the control and atherosclerosis group. CONCLUSIONS: Higher circulating anti-Hsp60 is associated with advanced cerebrovascular atherosclerosis as a consequence of the autoimmunity part of the inflammation and bursting of atherosclerosis. Higher levels of Hsp70 observed in the control group could be protective in the development of atherosclerotic changes.

Comparison of approaches and measurement of continuing professional development for specialists in laboratory medicine within four European countries.

BACKGROUND: This study investigated approaches to continuing professional development (CPD) for specialists in laboratory medicine within four European countries: Croatia, the Czech Republic, Malta and the UK. METHODS: The research questions focussed on ascertaining if continued registration/licence was linked to CPD and if so, were there requirements for certain amounts and types of CPD and for CPD activities to meet specified accreditation criteria. The Professional Associations Research Network (PARN) model of CPD measurement was applied to each country's registration/licencing body's CPD requirements. RESULTS: Our results indicate a spectrum of approaches to CPD within participating countries. CONCLUSIONS: It will be necessary for European employers to be familiar with these differences and to take them into account for this increasingly mobile European workforce.

Importance of urinary NGAL, serum creatinine standardization and estimated glomerular filtration rate in resistant hypertension.

In patients with resistant hypertension (RH) we investigated the importance of urinary neutrophil gelatinase-associated lipocalin (uNGAL- a chemiluminescent microparticle immunoassay (CMIA) method became using (Abbott Diagnostics) for the measurement of NGAL in urine samples) and incidence of chronic kidney disease using the Modification of Diet in Renal Disease Study (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in estimating glomerular filtration rate (eGFR) based on standardised serum creatinine method traceable to isotope dilution mass spectrometry (IDMS) method. It would have been difficult to predict that levels of these biomarker would perform better organ damage than traditional measurements of kidney function such as standardised serum creatinine, MDRD, or CKD-EPI equations in special population such as RH. Serum creatinine concentrations were measured in 50 patients (24M:26F from RH Registar in Clinical Hospital Merkur) by the kinetic Jaffe method. There were no significant differences between the GFR values derived by MDRD and CKD-EPI equations in the group of patients with RH. 62% of patients have eGFR > 60 mL/minl/1.73 m2, while a 38% of patients have eGFR < 60 mL/min/1.73 m2. The measurement of NGAL in urine samples of 40 patients with RH showed no difference and seems to be of no use in further determination of renal impairement. Higher value of uNGAL in some resistant hypertension patients could have link in the repair stage after AKI and would reveal pathways that could link AKI and CKD.

Trace elements and oxidative stress in hypertensive disorders of pregnancy.

PURPOSE: Due to increased metabolic requests, pregnancy can be considered as metabolic stress, especially if associated with oxidative stress triggered by disbalance of pro/antioxidants. The aim of the study was to determine serum concentrations of the trace elements iron (Fe), zinc (Zn) and copper (Cu) important in growth regulation and pro/anti-oxidant homeostasis, in relation to the total serum oxidant capacity (TOC) and total serum antioxidant capacity (TAC) in pregnant women with preeclampsia (n = 30) or with gestational hypertension (n = 30) and in healthy pregnant women (n = 37) and non-pregnant women (n = 30) as control groups expecting common differences between all pregnant women and controls and between preeclampsia and the other pregnancies indicating specific disbalance of the oxidative stress and analyzed trace elements. METHODS: Serum Fe was determined by spectrophotometric method, Cu and Zn were determined by atomic absorption spectrometry, TOC was determined by Enzymatic ANTIOX-CAP assay and TAC by Peroxide-activity assay. RESULTS: Serum Cu and TOC were significantly higher while Zn was lower in all pregnant groups regardless of hypertensive disorders. Serum Fe and TAC concentrations were found to be significantly higher in pregnant women with preeclampsia compared to pregnant controls. CONCLUSION: Increase of TOC in all pregnant women our study points to latent oxidative stress in pregnancy. Fe might have a role in etiopathogenesis of preeclampsia while the increase of TAC in the very beginning of preeclampsia might represent a stressdefence mechanism of the body. It has still to be revealed whether significantly higher serum Fe levels are associated with preeclampsia as a cause or as a consequence of this disorder.

Validation of a laboratory and hospital information system in a medical laboratory accredited according to ISO 15189.

INTRODUCTION: The aim of the study was to present a protocol for laboratory information system (LIS) and hospital information system (HIS) validation at the Institute of Clinical Chemistry and Laboratory Medicine of the Merkur University Hospital, Zagreb, Croatia. MATERIALS AND METHODS: Validity of data traceability was checked by entering all test requests for virtual patient into HIS/LIS and printing corresponding barcoded labels that provided laboratory analyzers with the information on requested tests. The original printouts of the test results from laboratory analyzer(s) were compared with the data obtained from LIS and entered into the provided template. Transfer of data from LIS to HIS was examined by requesting all tests in HIS and creating real data in a finding generated in LIS. Data obtained from LIS and HIS were entered into a corresponding template. The main outcome measure was the accuracy of transfer obtained from laboratory analyzers and results transferred from LIS and HIS expressed as percentage (%). RESULTS: The accuracy of data transfer from laboratory analyzers to LIS was 99.5% and of that from LIS to HIS 100%. CONCLUSION: We presented our established validation protocol for laboratory information system and demonstrated that a system meets its intended purpose.

Polymorphisms of pon1 and pon2 genes in hemodialyzed patients.

OBJECTIVES: Q192R, L55M and -108C>T polymorphisms of pon1 gene affect PON1 paraoxonase activity while S311C polymorphism of pon2 gene might be associated with coronary heart disease. The aims of this study were to determine the frequencies of Q192R, L55M, -108C>T and S311C polymorphisms in hemodialyzed patients and to examine the relationship between pon1 gene polymorphisms and PON1 paraoxonase activity in those patients. DESIGN AND METHODS: The study included 238 control subjects and 263 hemodialyzed patients. RESULTS: PON1 paraoxonase activity was lower in patients. Genotype frequencies were different between two compared groups only for L55M polymorphism, with control group having higher frequency of MM genotype. Polymorphisms of pon1 gene were associated with significant variation in PON1 paraoxonase activity in both study groups. CONCLUSION: Our results suggest that Q192R, L55M and -108C>T polymorphisms are not by itself the causal factors leading to the lower PON1 paraoxonase activity in hemodialyzed patients.

Serum platelet-activating factor acetylhydrolase and paraoxonase-1 activity in horses infected with Leptospira spp.

The aim of the study was to investigate the effect of infection with Leptospira spp. in horses on activities of platelet-activating factor acetylhydrolase (PAF-AH) and paraoxonase-1 (PON1) considering the anti-inflammatory/anti-oxidative properties of both enzymes. A total of 63 sport and leisure horses' sera were chosen among those routinely serologically examined on leptospirosis during the year 2009 in Croatia. Sera were divided into three groups according to the estimated level of antibody titre against Leptospira spp; group 1: sera serologically negative to leptospirosis (antibody titre<50) (n=21); group 2: sera with residual or anamnestic antibody titre (50-200) (n=23); group 3: sera with high antibody titre (≥1600) indicating recent Leptospira infection (n=19). Serum PAF-AH and PON1 activity was not significantly different between investigated groups (p>0.05). There were no statistical differences in lipid status parameters (p>0.05) among study groups as well. However, significant positive correlations (p<0.05) of PAF-AH and PON1 with total cholesterol and HDL-C were found. Results may indicate low levels of systemic inflammatory response and oxidative stress in horses with subclinical leptospirosis. Further studies with clinically manifested disease are needed to elucidate the potential role of PAF-AH and PON1 as prognostic markers of the leptospirosis outcome.

[The purpose of clinical laboratory accreditation in transplantation medicine]. / Znacenje akreditacije klinickih laboratorija u transplantacijskoj medicini.

Although transplantation of solid organs has become a more standardized method of treatment, liver transplantation represents an exceptional multidisciplinary clinical procedure requiring understanding of specific pathophysiological changes that occur in the end stage of liver disease. Liver transplantation has been performed at Merkur University Hospital since 1998, with 360 transplantations performed to date. The most common indications are alcohol liver disease, cirrhosis caused by hepatitis B and C virus, hepatocellular carcinoma and cryptogenetic liver cirrhosis. Laboratory tests required for liver transplantation are performed at Department of Clinical Chemistry, Merkur University Hospital, accredited according to ISO 15189 in 2007 for the areas of clinical chemistry, laboratory hematology and coagulation, laboratory immunology-cell immunophenotyping, and molecular diagnosis. The complexity of liver transplant patients requires constant interaction between the anesthesiologist team and clinical laboratory, which has to ensure fast and efficient intraoperative monitoring of biochemical and liver profile: electrolytes and acid-base status, complete blood count, coagulation profile and monitoring of graft function according to the individual patient's health status. Dynamics of intraoperative changes is measured in whole arterial blood samples on a Nova Biomedical Stat Profile Critical Care Xpress mobile acid-base analyzer. Frequent monitoring of ionized calcium and magnesium levels is very important because of citrated blood transfusion and for appropriate therapeutic procedure. During anhepatic stage, there is a progressive increase in lactate level concentration. After reperfusion, a rapid increase in lactate clearance is an excellent indicator of stable graft initial function and its adequate size. During the transplantation procedure, there is usually a biphasic acid-base disturbance characterized by metabolic acidosis and then by metabolic alkalosis. The loss of base equivalents starts during the dissection stage and accelerates during the anhepatic stage. Fast and efficient intraoperative monitoring of hematological tests and coagulation status is of great help in detecting the cause of possible hemorrhage and consequential complications during transplantation procedure. The possibility of organ and tissue transplantation mostly depends on well regulated international cooperation in the areas of donating, transplanting and exchange of required organs and tissues, while laboratory test results must be comparable regardless of their geographical area, methodology employed or analytical equipment used, which is mainly warranted through accreditation according to the international ISO 15189 standard.

[Standardization in laboratory hematology by participating in external quality assurance programs]. / Standardizacija u laboratorijskoj hematologiji sudjelovanjem u programima vanjske procjene kvalitete.

Since 1985, Department of Clinical Chemistry and Laboratory Medicine, Merkur University Hospital, Zagreb, has been participating in the International External Quality Assessment Scheme for Hematology (IEQAS-H) organized by the World Health Organization (WHO). Owing to very good results, in 1987 the Department received a certificate of participation in this control scheme. Department has been cooperating in the external quality assessment program in laboratory hematology which has been continuously performed in Croatia since 1986 by the Committee for External Quality Assessment Schemes under the auspices of the Croatian Society of Medical Biochemists and School of Pharmacy and Biochemistry, University of Zagreb. Nowadays, 186 medical biochemical laboratories are included in the National External Quality Assessment program, which is performed three times per year. Our Department has participated in the international projects of the European Committee for External Quality Assurance Programs in Laboratory Medicine (EQALM).

[Flow cytometry and acute renal rejection confirmed by histopathologic analysis]. / Protocna citometrija i akutno odbacivanje bubrega dokazano patohistoloskim nalazom.

Transplantation of solid organs, tissues or hematopoietic cells is now standard in the treatment of patients with terminal stage disease in order to cure and improve the recipients' quality of life. The study included 54 patients having undergone single or multiple organ transplantation. All patients received a combination of immunosuppressant therapy consisting of corticosteroids, calcineurin inhibitor (cyclosporine; tacrolimus), anti-CD25 (daclizumab) and mycophenolate-mofetil. In 24 patients, acute rejection was stratified by histopathologic analysis of renal biopsy. Fifteen highly sensitized patients were administered antithymocyte globulin (ATG) therapy. Absolute count and percentage of B/T lymphocyte subsets, NK cells and CD25+ or CD69+ activated T cells were measured on a flow cytometer (EPICS XL, Coulter) using single platform standardized protocol. Upon ATG therapy, rapid decline to a very low level of T and NK cell lymphocyte count was observed, as well of B lymphocytes, resulting in redistribution of lymphocyte compartment. Between consecutive measurements, kinetic changes of lymphocyte subset numbers (absolute count or percentage) did not differ in a large spectrum of immune parameters between the groups with and without rejection episode and having received quadruple immunosuppressive induction and maintenance therapy. Immunologic monitoring must be initiated prior to transplantation and continued consistently and frequently post-transplantation. Such a program is expensive and time-consuming and stressful for the patient, therefore, prospective studies should identify whether treatment decisions can be based reliably on these immune parameters. Serial measurement of immune cell counts is necessary for maintenance of ATG therapy and could be useful for monitoring patient recovery.

[Significance of participation in programs of external quality assessment in molecular diagnostic--our experience]. / Znacenje sudjelovanja u programima vanjske procjene kvalitete u molekularnoj dijagnostici--vlastita iskustva.

Harmonization of molecular diagnostic tests in laboratories in the Republic of Croatia has only just started. According to laboratory accreditation standard ISO 15189 participation in external quality assessment (EQA) schemes or programs is a prerequisite and support tool for clinical laboratory accreditation process. As there are no national quality assurance schemes yet, an European external quality assessment (EQA) scheme or program should be found. Because of variation in the molecular diagnostic test performance of clinical laboratories across Europe, EQA is recognized as a system whereby a set of reagents and techniques are assessed by an external provider making inter-laboratory performance comparability possible through already integrated recommendations and practice guidelines of molecular diagnostic test performance. Today, wide range of various EQA schemes and programs already in action have been available and most of them began within the last ten years. This paper is therefore intended to present and summarize the four-year EQA activities in the Institute of Clinical Chemistry, Merkur University Hospital, in three different international EQA schemes: United Kingdom National External Quality Assessment Scheme (UK NEQAS), the European Molecular Genetic Quality Network (EMQN) and Multi-National External Quality Assay program (EQUAL- qual)) and to point out their educational role in standardization of laboratory performance of any test intended for patient testing. from a laboratory point of view.

Effect of non-genetic factors on paraoxonase 1 activity in patients undergoing hemodialysis.

OBJECTIVES: Hemodialyzed patients have lower paraoxonase 1 (PON1) activity. Higher mortality risk from cardiovascular disease observed in these patients could be due to the low antiathetrogenic activity of PON1. Understanding the mechanism that causes lower PON1 activity could provide the possibility for modulation of enzyme activity in purpose of preventing and/or decreasing development of atherosclerosis. DESIGN AND METHODS: 87 healthy individuals and 71 hemodialyzed patients were enrolled in this study. RESULTS: Hemodialyzed patients had reduced PON1 paraoxonase and arylesterase activity, concentrations of HDL, HDL(3) and HDL(2) and concentrations of free thiol groups. Distribution of HDL subfractions and distribution of PON1 phenotypes as well as concentrations of MDA were not different between two study groups. In the in vitro experiment high concentrations of urea, creatinine, uric acid and addition of patient's sera ultrafiltrate did not significantly affect PON1 paraoxonase activity. CONCLUSION: Decreased HDL concentration as well as lower PON1 concentration (shown indirectly by the enzyme arylesterase activity) might contribute, at least partly, to the reduced PON1 activity observed in hemodialyzed patients. Decreased concentration of free thiol groups in sera suggest that free thiol group (Cys284) in PON1 might also be oxidized, which can affect PON1 activity.

Flow cytometry immunophenotyping (FCI) of fine needle aspirates (FNAs) of lymph nodes.

Flow cytometry immunophenotyping (FCI) has an important role in the clinic work-up of fine needle aspirates (FNAs) of lymph nodes. Its standardization has been defined by proposed analytical protocols and procedures used to assure proper analytical results also in those non-routine samples. In Institute of Clinical Chemistry, "Merkur" University Hospital, FCI is accredited method according to laboratory accreditation standard ISO 15189. According to this laboratory accreditation standard, participation in external quality assessment (EQA) programs is a prerequisite for assuring integrity and quality of the entire laboratory process. A critical analysis of our institutional experience in the feasibility of FCI of the material obtained by FNA of lymph nodes with suspected lymphoma represented the purpose of the study. During an eight-year period in Institute of Clinical Chemistry, "Merkur" University Hospital, a total of 1295 FNA analysis was done, 245 of them with a possible diagnosis of B-cell Non-Hodgkin lymphomas (B-NHL) formed the basis of the study. Lymphocytes were isolated on density gradient according to Boyum et al. The average feasibility of FNAs for FCI analysis was 86% (ranged 78-93%). An acceptable total cell number in FNAs for FCI analysis (4257) was established. In total population of respondents statistical significances in expressions of cellular antigens CD3, CD5, CD22, CD23, CD19 and CD5 on B-cells (CD5+CD19+) between patient's with final diagnosis of benign, reactive lymphoid proliferations and patient's with diagnosis of B-NHL were found. EQA results analysis showed that all results were either inside target values (X +/- 1SD) or inside accepted values (X +/- 2SD). Compatibility of the restriction of immunoglobulins light chains determinated by FCI and cytomorphology diagnosis depends on the choice of criterion values of the light chains ratio which determine the monoclonality. According to the matrix of shares of all classified data of retained neural network, ranges of diagnostic sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and prevalency of 82%, 72%, 93%, 48%, and 72% were produced. As a conclusion, FCI is a reliable methodology for phenotyping FNAs of lymph nodes with suspected B-NHLs detecting their clonality easily.

Accreditation of medical laboratories in Croatia--experiences of the Institute of Clinical Chemistry, University Hospital "Merkur", Zagreb.

Since 2003 when the international norm for implementation of quality management in medical laboratories (EN ISO 15189, Medical laboratories--Particular requirements for quality and competence) was established and accepted, accreditation has become practical, generally accepted method of quality management and confirmation of technical competence of medical laboratories in the whole world. This norm has been translated into Croatian and accepted by the Croatian Institute for Norms as Croatian norm. Accreditation is carried out on voluntary basis by the Croatian Accreditation Agency that has up to now accredited two clinical medical biochemical laboratories in the Republic of Croatia. Advantages of accredited laboratory lie in its documented management system, constant improvement and training, reliability of test results, establishing users' trust in laboratory services, test results comparability and interlaboratory (international) test results acceptance by adopting the concept of metrological traceability in laboratory medicine.

Applicability of common reference intervals for serum creatinine concentrations to the Croatian population.

BACKGROUND: In accordance with an ongoing activity for worldwide harmonization based on traceability in laboratory methods, the goal of this study was to validate the applicability of recommended "common" reference intervals for serum creatinine concentrations using a specific enzymatic method to the Croatian population. METHODS: The reference group consisted of 240 healthy subjects (120 males and 120 females), between 18 and 74 years of age (median 57 years), who were selected in accordance with the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) recommendations. Creatinine in serum was measured using the creatinine enzymatic assay (Olympus OSR61204) that was standardized to the isotopic dilution mass spectrometry (IDMS) method and National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) 967. In addition, creatinine was measured using a kinetic Jaffe method (Olympus OSR6178) standardized to NIST SRM 909b level 2 standard. RESULTS: Method comparison between enzymatic creatinine (x) and the Jaffe kinetic method (y) gave the following P/B equation for the entire group (n=240): y=1.00x+17.00; r=0.968. Reference intervals for serum creatinine (central 95th percentiles) obtained using the enzymatic creatinine method ranged from 54 to 107 micromol/L for males and from 50 to 93 micromol/L for females. The IFCC recommended common reference intervals for global applications are 64-104 micromol/L and 49-90 micromol/L for males and females, respectively. CONCLUSIONS: Comparability of obtained results confirmed the applicability of recently recommended "common" reference intervals to the Croatian population for all laboratories measuring serum creatinine concentrations using enzymatic methods traceable to the IDMS method and NIST SRM 967.

Effect of splenectomy and autologous spleen transplantation on the serum platelet-activating factor acetylhydrolase (PAF-AH) activity and acute phase response (APR) in a porcine model.

The aim of this study was to evaluate the inflammatory response after total splenectomy and spleen autotransplantation in a porcine model by measuring serum platelet-activating factor acetylhydrolase activity, C-reactive protein and albumin concentrations. Nineteen piglets were used in the experiment. After induction of anesthesia, animals were randomly divided into three groups: sham-operation with spleens intact (n = 6), total splenectomy (n = 6), and splenic autotransplantation (n = 7) with small fragments of the spleen autotransplanted into the greater omentum. The blood samples were taken just before surgery and on day 1st, 5th, 12th, 26th and 40th postoperatively. PAF-AH activity, CRP and albumin concentrations were assayed in the sera. After total splenectomy, PAF-AH activity was significantly increased on day 5th, while there was no significant increase after spleen autotransplantation or the sham-operation. CRP was significantly increased after surgery in all experimental groups. Albumin was significantly decreased after surgery from day 5th until day 40th in splenectomized and autotransplanted pigs. Increased PAF-AH activity after splenectomy and spleen autotransplantation might be attributed to inflammatory conditions due to the loss of splenic tissue and trauma. Time-course increase of CRP, in all groups after surgery suggests post-injury inflammatory response due to tissue lesion during operation.

Bovine platelet-activating factor acetylhydrolase (PAF-AH) activity related to fertility.

Plasma platelet-activating factor acetylhydrolase (PAF-AH), the enzyme characterized by the association with plasma lipoproteins, degrades platelet-activating factor (PAF) as well as PAF-like oxidatively fragmented phospholipids produced during oxidative stress. Apart from pro-inflammatory properties, PAF is also related to reproductive processes and successful fertility. In order to get a better insight into the involvement of PAF-AH in the fertility of cows, the aim of the study was to determine the PAF-AH activity as well as the C-reactive protein, cholesterol and high density lipoprotein-cholesterol (HDL-C) in the serum of dairy cows throughout the pregnancy and lactation, as well as in infertile cows. The results showed that serum PAF-AH activity changes throughout pregnancy and lactation with a lower level during periparturient period. It is also found higher PAF-AH activity in lactating cows with reproductive disorders compared to high lactating cows without reproductive disorders. Strong correlation between PAF-AH activity and HDL-C concentration indicates that HDL could have considerable influence on PAF-AH activity in bovine plasma. CRP concentration was also lower during transition period suggesting that lactation might stimulate CRP synthesis in bovine. A higher CRP concentration in cows with reproductive disorders compared to fertile cows at the peak of lactation, demonstrates that milk production is not the only factor influencing CRP in cows. A significant correlation between PAF-AH activity and CRP level shows that both parameters could be influenced by reproductive status of dairy cows.

Atherosclerotic lesions of supra-aortic arteries in diabetic patients.

The aim of this prospective study was to determine the prevalence and localization of stenotic atherosclerotic lesions of supra-aortic arteries in diabetic patients according to age and sex. Angiograms obtained by digital subtraction angiography were analyzed in 150 diabetic patients (study group) and 150 non-diabetic patients (control group) with symptoms of cerebral ischemia. Diabetic patients were found to have a significantly higher prevalence of stenotic atherosclerotic lesions of the internal carotid artery. Lesions of the large supra-aortic arteries were significantly more common in the left than in the right side of the neck (p < 0.001), but the difference between the diabetic and the non-diabetic group did not reach statistical significance. Hemodynamic conditions were found to be more important than diabetes for the occurrence of atherosclerotic lesions in these arteries. Changes in the proximal segment of the left common carotid artery were the most common finding in diabetic patients, hence attention should be paid to this localization on control examinations.