Risk Evaluation for Coating Thickness Conformity Assessment.

This paper presents the conformity assessment process of the epoxy coating thickness applied on water pipes made of gray cast iron with the specifications given for this kind of coating appliance. An epoxy coating was applied to prevent a special form of corrosion called the graphitization of cast iron. In order for the pipe to withstand its designed service life, it is necessary to ensure the required thickness of the applied coating. In accordance with the EN 877 norm, the thickness of the epoxy coating on the pipes for the projected corrosiveness of the environment C4 and the durability of 20 years is at least 70 µm and this indicates the required accuracy of the product. To achieve the desired product quality, statistical control of the coating application process was carried out and the impact of uncertainty associated with the measurement result was analyzed. Considering the quality of the coating application process and the quality of the measuring system, and to ensure the quality of products and to reduce consumer risk, the optimal thickness of the coating was determined.

REASONS FOR DEFERRAL IN DEFERRED VOLUNTARY BLOOD DONORS IN EASTERN CROATIA.

When choosing a voluntary blood donor (VBD), it is important to ensure the donor health, and at the same time to produce a quality and safe blood product. The donor selection process leads to donor rejection related to their current health condition. The aim of this study was to determine gender differences in VBDs, to examine the reasons for their rejection, and to determine the share of permanently and temporarily deferred VBD, especially due to low hemoglobin levels. The research was conducted in eastern Croatia in the 2014 to 2018 period. The study included 144,041 blood donations from a total of 80,418 VBDs, of which 83.3% of donations were from male VBDs and 16.7% from female VBDs. There were 11.46% of temporarily deferred and permanently rejected donors. Out of all temporarily deferred donors and possible reasons for deferral, the largest share of deferrals referred to a reduced hemoglobin level, which accounted for 54% in female VBD and 46% in male VBD. Female VBDs made up to one-third of total VBDs and account for one-sixth of total blood donations. Low hemoglobin was the most common reason for VBD deferral. Gender and age are related to blood hemoglobin levels in rejected and accepted donors. Female VBDs represent a potential reservoir for increasing the total number of VBDs.

THE IMPACT OF POSITIVE ANTI-HBC MARKER ON PERMANENT DEFERRAL OF VOLUNTARY BLOOD DONORS IN EASTERN CROATIA AND ESTIMATION OF OCCULT HEPATITIS B VIRUS INFECTION RATE.

Recently an increase has been reported in the number of HBV transmissions from anti-HBc positive blood donors that were repeatedly negative in HBsAg and nucleic acid testing using the most sensitive tests available. The aim of the study was to show the effect of anti-HBc antibody testing performed in 2006 on permanent deferral of voluntary blood donors (VBDs), and to estimate occult hepatitis B infection (OBI) rate in this population after the introduction of mandatory molecular testing in the 2013-2016 period. More than 30,000 blood donations collected during the 2005-2007 period and more than 14,000 VBDs having donated blood during the 2013-2016 period after the introduction of molecular testing from eastern Croatia were included in the study. Serologic testing was performed with HBsAg assay throughout the study period, and anti-HBc assay was only performed in 2006. As part of the confirmatory algorithm testing, all HBsAg positive and unclear results were tested with molecular tests. Anti-HBc prevalence among VBDs in 2006 was 1.5%, with a rate of 1:197, whereas HBsAg prevalence was stable from 2005 to 2007 (0.04%, 0.1% and 0.1%, respectively). The calculated OBI rate from 2013 to 2016 was 1:30,250. Ten of 161 (12.4%) VBDs had serologic anti-HBc-only pattern. Anti-HBc testing in 2006 resulted in statistically more deferrals of VBDs compared to 2005 and 2007, and to the rest of Republic of Croatia. The strategy of universal anti-HBc testing of VBDs in addition to the existing HBsAg and molecular screening could be an additional measure to prevent HBV transmission by blood and blood components.

HLA-A, -B, -C, -DRB1, -DQA1, and -DQB1 allele and haplotype frequencies defined by next generation sequencing in a population of East Croatia blood donors.

Next-generation sequencing (NGS) is increasingly used in transplantation settings, but also as a method of choice for in-depth analysis of population-specific HLA genetic architecture and its linkage to various diseases. With respect to complex ethnic admixture characteristic for East Croatian population, we aimed to investigate class-I (HLA-A, -B, -C) and class-II (HLA-DRB1, -DQA1, -DQB1) HLA diversity at the highest, 4-field resolution level in 120 healthy, unrelated, blood donor volunteers. Genomic DNA was extracted and HLA genotypes of class I and DQA1 genes were defined in full-length, -DQB1 from intron 1 to 3' UTR, and -DRB1 from intron 1 to intron 4 (Illumina MiSeq platform, Omixon Twin algorithms, IMGT/HLA release 3.30.0_5). Linkage disequilibrium statistics, Hardy-Weinberg departures, and haplotype frequencies were inferred by exact tests and iterative Expectation-Maximization algorithm using PyPop 0.7.0 and Arlequin v3.5.2.2 software. Our data provide first description of 4-field allele and haplotype frequencies in Croatian population, revealing 192 class-I and class-II alleles and extended haplotypic combinations not apparent from the existing 2-field HLA reports from Croatia. This established reference database complements current knowledge of HLA diversity and should prove useful in future population studies, transplantation settings, and disease-associated HLA screening.

The investigation of hereditary and acquired thrombophilia risk factors in the development of complications in pregnancy in Croatian women.

OBJECTIVES: To investigate the genetic and acquired thrombophilic risk factors in pregnancy-associated complications and venous thromboembolism (VTE) and evaluate the association between particular thrombophilic risk factors and thromboembolic complications. METHODS: In this study, pregnant women with pregnancy complications and VTE (N = 101) were the study group, and the control group were women with normal pregnancy (N = 102). All women underwent testing for factor V Leiden mutation (FVL), mutation of the coagulation factors II (FII20210), methylenetetrahydrofolate reductase (MTHFR), plasminogen activator inhibitor-1, antithrombin III (ATIII), protein C (PC) and protein S, lupus anticoagulant (LAC) antibodies, anticardiolipin antibodies and anti-beta-2-glycoprotein-1. RESULTS: In this study group, mutations of the FVL was 15.8% (16/101), FII20210 5.9% (6/101) and the MTHFR at locus 677 was TT in 19.8% (20/101). Deficiency of ATIII and PC were rare: 3.0% and 1.0%, respectively. LAC were significantly higher in the study group than in the control group: 32.7% versus 3.9%; p < 0.0005. Pregnant women with VTE have been more frequent for FVL (41.7%; p < 0.005), PC deficiency (25.0%; p < 0.005) and LAC (33.3%; p < 0.005). Combination of FVL and MTHFR mutation was related to the risk of recurrent fetal death and habitual abortion. CONCLUSION: The inherited and the acquired thrombophilic risk factors were found to be up to 10 times more common in the study group than in the control group.

VKORC1 gene polymorphisms and adverse events in Croatian patients on warfarin therapy.

OBJECTIVE: The objective was to determine the impact of VKORC1 polymorphisms on warfarin anticoagulant therapy (stable warfarin maintenance dose, time required to reach therapeutic dose and time spent in therapeutic range) and its adverse events (overanticoagulation and bleeding events, time to first overanticoagulation or bleeding event, and therapy for bleeding events) in Croatian patients. MATERIALS: Blood samples were collected from 186 patients on stable warfarin therapy. METHODS: VKORC1 1173C>T and VKORC1 –1639G>A gene polymorphisms were analyzed using real-time PCR. Prothrombin time international normalized ratio (INR) values were determined and overanticoagulation as well as bleeding events were recorded. RESULTS: Both tested VKORC1 gene polymorphisms (VKORC1 1173C>T and VKORC1 -1639G>A) were in perfect linkage disequilibrium. Genotype analysis showed that 33.9% of patients were homozygous for wild-type, 46.8% were heterozygous and 19.4% were homozygous for the variant allele. We have found a statistically significant difference between variantallele carriers and wild-type patients in stable warfarin maintenance dose (p<0.001) and incidence of bleeding events (p=0.040). Patients homozygous for variant-allele were more likely to experience an overanticoagulation event in the first 30 days of therapy (p=0.040). CONCLUSIONS: Our study showed that VKORC1 1173C>T and VKORC1 -1639G>A gene polymorphisms are associated with stable warfarin maintenance dose and adverse events of warfarin therapy.

Importance of interleukin 6 in pathogenesis of inflammatory bowel disease.

Inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn's disease (CD), is an uncontrolled chronic inflammation of the gastrointestinal tract caused by an interaction of diverse genes and environmental factors. There is growing evidence that cytokine production plays an important role in IBD. One of the key roles in signaling pathway in development of IBD is performed by interleukin 6 (IL-6), although molecular mechanism of this pathway is not yet fully understood. In order to assess the clinical relevance of IL-6 serum concentration in patients with CD and UC we performed cross-sectional, case-control study of IL-6 levels in patients' and healthy blood donors' sera. A total of 100 CD and UC patients and 71 healthy blood donors were investigated. Clinical activity of CD and UC was evaluated using the Crohn's disease activity index and Truelove-Witt's criteria, respectively. Quantitative assessment of serum IL-6 was performed with solid-phase, enzyme-labeled, chemiluminescent sequential immunometric assay. Our results indicate that serum IL-6 is a clinically relevant parameter for CD and UC that strongly correlates with inflammatory activity of disease. We confirmed and extended the role of cytokine production patterns for IBD presentation in Croatian population.

Vitamin K epoxide reductase complex 1 (VKORC1) gene polymorphisms in population of Eastern Croatia.

Vitamin K epoxide reductase (VKOR) is a key enzyme in the y-carboxylation of proteins associated with important bodily functions (coagulation, bone metabolism, etc.). This feature is particularly used in warfarin therapy, which blocks the VKOR enzyme and leads to production of dysfunctional coagulation proteins. Genetic factors, particularly vitamin K epoxide reductase complex 1 (VKORC1) gene, have greatest influence on warfarin therapy. The aim of this study was to determine the distribution of VKORC1 1173C > T and VKORC1 -1639G > A polymorphisms, which are most important for warfarin therapy. We investigated 420 unrelated healthy individuals, mostly blood donors, from region of the Eastern Croatia. Both investigated polymorphisms were in perfect linkage disequilibrium (LD) and showed identical results. 151 patients (36%) were homozygous for the wild-type (C/C and G/G), 196 (47%) were heterozygous (C/T and G/A) and 73 (17%) were homozygous for the variant allele (T/T and A/A). Number of normal alleles among individuals was 498 (59.3%), and number of variant alleles was 342 (40.7%). The data obtained are in good agreement with the results of studies in other European populations.

The influence of the different morphological changes on gastric mucosa on somatostatin cell number in antrum mucosa and serum somatostatin.

The aim of our paper was to investigate the influence of the different morphological changes on gastric mucosa on somatostatin D-cell number in antral mucosa and serum Somatostatin. We analyzed according to Sydney classification to what extent the severity of gastritis affect the observed hormonal values. somatostatin D-cell number in antral mucosa and serum Somatostatin values were compared between three groups of patients; mild, moderate and severe chronic gastritis. The average number of somatostatin cell in biopsy sample of antrum mucosa was 30.41 +/- 35.38 (N = 17) in the case of middle form, 18.69 +/- 26.65 (N = 56) in moderate and in severe case of chronic gastritis 5.23 +/- 5.93 (N = 7) cells in mm2 of mucosa. The level of somatostatin in the serum of middle form gastritis were 26.43 +/- 28.76, moderate 19.95 +/- 35.93 and severe 17.88 +/- 17.66 pg/mL. In order to determine the number of somatostatin cells in antrum mucosa and serum somatostatin with present morphological changes of mucosa, it might helpful to exclude the patients with non-ulcer dyspepsia, but with the higher risk of premalignant and malignant changes.

Evaluation of fresh frozen plasma usage at the University Hospital Center Rijeka.

The aim of this investigation was to assess the rate and appropriate use of fresh frozen plasma (FFP) at the Clinical Hospital Center Rijeka in two six-month periods, at an interval of 5 years, before and after introducing clinical standards for transfusion practice and hemovigilance, and to evaluate the results of applied measures. We studied 315 patients transfused with 1341 doses of FFP in two six-month periods from September to February of 1999/2000 and 2004/2005. The first period (1999/00) of the study was retrospective and 226 patients were transfused with 928 FFP units. The second period (2004/05) was prospective and we studied 89 patients transfused with 413 units. In the first period blood bank records were retrospectively reviewed and in the second period all FFP requests, performed coagulation tests and transfusion episodes were prospectively analyzed. The number of inappropriate transfusions decreased from 39.8% to 23.6%. In most patients (85.1%), coagulation tests were made prior to FFP transfusion. The number of patients transfused with one and two FFP doses decreased, while those transfused with three or more doses increased. Most of the appropriately transfused patients were those with active bleeding due to coagulation factor deficiency and massive transfusions. The least were those requiring reversal of warfarin effect. Our results demonstrated a decrease in the number of patients treated with FFP in the second period. The introduction of clinical standards of good transfusion practice and hemovigilance showed positive effects. Considering that there was a number of inappropriately transfused patients continued education of all health personnel engaged in transfusion treatment is evidently necessary.

Association of CYP2C9 gene polymorphism with bleeding as a complication of warfarin therapy.

The aim of this study was to determine the association of bleeding as a complication of warfarin therapy with polymorphism of CYP2C9 gene (alleles 1, 2 and 3). The CYP2C9 is the main enzyme for warfarin metabolism. Study included 181 patients receiving warfarin for at least one month. Allele 1 of CYP2C9 gene (in 94.5%) and genotype *1/*1 (57.5%) prevailed. Allele 3 was found in 12.7% patients. Bleeding side-effects occurred in 18 patients (10%). Patients with allele *1 needed significantly higher maintenance warfarin dose (p=0.011). Those with allele *3 had significantly lower maintenance warfarin dose (p=0.005) and higher prothrombin time (PT) at induction (p=0.034). Bleeding occurred significantly more often in those with lower maintenance warfarin dose (p=0.017). Patients with allele *3 had increased risk of bleeding, with marginal significance (p=0.05). Polymorphism of CYP2C9 could determine dose of warfarin therapy and thus it could be related to the risk of bleeding complications. Allele *3 carriers need lower warfarin dose. Therefore, initially reduced warfarin induction dose in allele *3 carriers could avoid more prolonged PT and decrease the risk of bleeding complication.

Matrix metalloproteinase-9 and cell kinetics during the collection of peripheral blood stem cells by leukapheresis.

The plasma levels of matrix metalloproteinase-9 (MMP-9) were determined during 41 collections of peripheral blood stem cells (PBSC) by standard volume (two blood volumes) leukaphereses (SVL) in 29 donors (7 allogeneic and 22 autologous) mobilized with the granulocyte-colony stimulating factor (G-CSF). The association between MMP-9 levels and cell counts in donor's blood was explored. During the processing of the first blood volume (BV), MMP-9 levels declined on average by 31% and persisted at the same level during the processing of the second BV. During the collection, a slight decline of white blood cells (WBC), polymorphonuclear neutrophils (PMN) and platelets (PLT) in donor's blood was accompanied by a significant drop of CD34+ cells by 37% after 1 BV and by 44% after 2 BV had been processed (p=0.001). The drop of MMP-9 plasma levels showed a loose correlation with the decrease of WBC (r=0.68, p=0.002) and PMN counts (r=0.67, p=0.001). We conclude that the levels of MMP-9 that have been elevated by the mobilization of donors with G-CSF, decrease during the collection of PBSC by 4h SVL. The observed decrease was indirectly related to the drop of WBC and PMN counts, suggesting that certain other factors have an influence on MMP-9 kinetics during PBSC collection.

Association between the CYP2C9 polymorphism and the drug metabolism phenotype.

CYP2C9, an isoform of the cytochrome P450 enzyme, is involved in the metabolism of most of the drugs of choice for the treatment of thromboembolic disorders. Functional polymorphism is associated with two variant alleles (alleles *2 and *3) encoding CYP2C9 enzymes with a potentially different catalytic activity. The aim of the study was to determine the frequency of the CYP2C9 polymorphism in a representative sample of the Croatian population (n = 177) and to assess the association between the CYP2C9 polymorphism and the warfarin dose in patients with thromboembolism (n = 181). The CYP2C9 genotype was determined by polymerase chain reaction-restriction fragment length poymorphism (PCR-RFLP). According to the CYP2C9 genotype distribution, 31.2% of the healthy subjects were identified with a heterozygous or homozygous CYP2C9 variant genotype. The frequency of 2C9*2 and 2C9*3 alleles was 12.4% and 3.7%, respectively. There was no gender-related genotype or allele difference. In thromboembolism patients, the frequency of CYP2C9 alleles *2 and *3 was 17.4% and 6.6%, respectively, and did not differ significantly from the control group. Almost half (42.5%) of the patients carried at least one variant CYP2C9 genotype. The allele difference between patient subgroups receiving warfarin doses lower and higher than the optimal warfarin dose (4.1 mg/day) was significant (p = 0.027), especially for allele 2C9*3 (p = 0.019; OR 3.250, 95%, CI 1.263-8.413). Comparison of the warfarin dose between patients with different genotypes yielded a significant dose difference between the patients with wild-type genotype and those with variant genotypes (Kruskall-Wallis, chi2 = 9.745, p = 0.008). The results of the association of each of five genotype combinations with the warfarin maintenance dose revealed it to be significantly related to the genotype (Kruskall-Wallis, chi2 = 12.854, p = 0.025). Expressed as percentage of the mean dose in patients with wild-type alleles, the mean warfarin maintenance dose was 92% in 2C9*2 heterozygotes, 74% in 2C*3 heterozygotes, 61% in 2C9*2 homozygotes, 34% in 2C9*3 homozygotes and 63% in compound heterozygotes for 2C9*2 and 2C9*3. Although the mean maintenance dose in homozygous *2/*2 and compound *2/*3 genotype patients was markedly lower (mean 2.66 mg and 2.75 mg, respectively, vs. 4.37 mg), statistical analysis yielded no significance because of the small number of patients carrying these genotypes. A significantly lower maintenance dose was observed in the subgroup of heterozygous *1/*3 genotype patients (p = 0.022). These preliminary results suggest a significant association of the CYP2C9 polymorphism with the warfarin dose and underline the importance of pre-therapeutic genotyping to identify the subjects likely to develop undesirable drug effects.