The role of urinary N-acetyl-ß-D-glucosaminidase in early detection of acute kidney injury among pediatric patients with neoplastic disorders in a retrospective study.

BACKGROUND: The 1-year cumulative incidence of AKI reportedly is high (52%) in pediatric neoplastic disorders. About half of these events occur within 2 weeks. However, subclinical AKI episodes may remain unrecognized by the conventional creatinine-based approaches. We investigated the diagnostic value of urinary N-acetyl-ß-D-glucosaminidase (uNAG) as an early marker of acute kidney injury (AKI). METHODS: In our retrospective study, 33 children with neoplastic disorders were inculded who had serial uNAG tests (at least 5 samples/patient) with a total of 367 uNAG measurements. Renal function was determined by cystatin-C and creatinine based GFR, and relative increase of uNAG index (uNAGRI). We focused on detecting both clinical and subclinical AKI episodes (according to Biomarker-Guided Risk Assessment using pRIFLE criteria and /or elevated uNAG levels) and the incidence of chronic kidney damage. RESULTS: Sixty episodes in 26 patients, with positivity at least in one parameter of kidney panel, were identified during the observation period. We detected 18/60 clinical and 12/60 subclinical renal episodes. In 27/60 episodes only uNAG values was elevated with no therapeutic consequence at presentation. Two patients were detected with decreased initial creatinine levels with 3 "silent" AKI. In 13 patients, modest elevation of uNAG persisted suggesting mild, reversible tubular damage, while chronic tubuloglomerular injury occurred in 5 patients. Based on ROC analysis for the occurence of AKI, uNAGRI significantly indicated the presence of AKI, the sensitivity and specificity are higher than the changes of GFRCreat. Serial uNAG measurements are recommended for  the reduction of the great amount of false positive uNAG results, often due to overhydratation. CONCLUSION: Use of Biomarker-guided Risk Assessment for AKI identified 1.5 × more clinical and subclinical AKI episodes than with creatinine alone in our pediatric cancer patients. Based on the ROC curve for the occurence of AKI, uNAGRI has relatively high sensitivity and specificity comparable to changes of GFRCysC. The advantage of serial uNAG measurements is to decrease the number of false positive results. TRIAL REGISTRATION: The consent to participate is not applicable because it was not reqired for ethical approval and it is a retrospectiv study.

Transglutaminase 2 Has Metabolic and Vascular Regulatory Functions Revealed by In Vivo Activation of Alpha1-Adrenergic Receptor.

The multifunctional tissue transglutaminase has been demonstrated to act as α1-adrenergic receptor-coupled G protein with GTPase activity in several cell types. To explore further the pathophysiological significance of this function we investigated the in vivo effects of the α1-adrenergic receptor agonist phenylephrine comparing responses in wild type and TG2-/- mice. Injection of phenylephrine, but not a beta3-adrenergic agonist (CL-316,243), resulted in the long-term decline of the respiratory exchange ratio and lower lactate concentration in TG2-/- mice indicating they preferred to utilize fatty acids instead of glucose as fuels. Measurement of tail blood pressure revealed that the vasoconstrictive effect of phenylephrine was milder in TG2-/- mice leading to lower levels of lactate dehydrogenase (LDH) isoenzymes in blood. LDH isoenzyme patterns indicated more damage in lung, liver, kidney, skeletal, and cardiac muscle of wild type mice; the latter was confirmed by a higher level of heart-specific CK-MB. Our data suggest that TG2 as an α1-adrenergic receptor-coupled G protein has important regulatory functions in alpha1-adrenergic receptor-mediated metabolic processes and vascular functions.

Browning deficiency and low mobilization of fatty acids in gonadal white adipose tissue leads to decreased cold-tolerance of transglutaminase 2 knock-out mice.

During cold-exposure 'beige' adipocytes with increased mitochondrial content are activated in white adipose tissue (WAT). These cells, similarly to brown adipose tissue (BAT), dissipate stored chemical energy in the form of heat with the help of uncoupling protein 1 (UCP1). We investigated the effect of tissue transglutaminase (TG2) ablation on the function of ATs in mice. Although TG2+/+ and TG2-/- mice had the same amount of WAT and BAT, we found that TG2+/+ animals could tolerate acute cold exposure for 4h, whereas TG2-/- mice only for 3h. Both TG2-/- and TG2+/+ animals used up half of the triacylglycerol content of subcutaneous WAT (SCAT) after 3h treatment; however, TG2-/- mice still possessed markedly whiter and higher amount of gonadal WAT (GONAT) as reflected in the larger size of adipocytes and lower free fatty acid levels in serum. Furthermore, lower expression of 'beige' marker genes such as UCP1, TBX1 and TNFRFS9 was observed after cold exposure in GONAT of TG2-/- mice, paralleled with a lower level of UCP1 protein and a decreased mitochondrial content. The detected changes in gene expression of Resistin and Adiponectin did not provoke glucose intolerance in the investigated TG2-/- mice, and TG2 deletion did not influence adrenaline, noradrenaline, glucagon and insulin production. Our data suggest that TG2 has a tissue-specific role in GONAT function and browning, which becomes apparent under acute cold exposure.

Altered lipid subfraction profile and impaired antioxidant defense of high-density lipoprotein in Smith-Lemli-Opitz syndrome.

BACKGROUND: Smith-Lemli-Opitz syndrome (SLOS) is a rare disease caused by biallelic mutation in the 7-dehydrocholesterol (7DHC) reductase gene. High oxidizability of 7DHC and the appearance of small-sized low-density lipoprotein (LDL) subfractions indicate increased endogenous oxidative stress that is counterbalanced by natural antioxidant defense mechanisms including the high-density lipoprotein (HDL)-associated paraoxonase-1 (PON1) enzyme. PON1 prevents lipoproteins from oxidative modifications; however, PON1 activity and the distribution of lipoprotein subfractions have not been studied in SLOS. METHODS: 7DHC levels and PON1 arylesterase activities were measured spectrophotometrically in 11 SLOS patients and 10 healthy children. Lipoprotein subfractions were detected by polyacrylamide gel electrophoresis. RESULTS: Compared to controls, there was a shift towards the small-dense LDL subfraction and the large HDL subfraction in SLOS. PON1 arylesterase activity was significantly decreased in SLOS patients and correlated negatively with the proportion of small-dense LDL subfraction and the proportion of large HDL subfraction. Significant positive correlations were detected between PON1 arylesterase activity and the ratios of intermediate and small HDL subfractions. CONCLUSIONS: Decreased PON1 activity and the deleterious shift in the distribution of lipoprotein subfractions may contribute to the impaired antioxidant status observed in SLOS. Monitoring of serum PON1 arylesterase activity may be a complementary biomarker in SLOS.

[Inborn error of cholesterol biosynthesis: Smith-Lemli-Opitz syndrome]. / A koleszterin-bioszintézis veleszületett zavara: a Smith-Lemli-Opitz-szindróma.

Smith-Lemli-Opitz syndrome is an autosomal recessive mental retardation and multiple malformation syndrome caused by deficiency of the 7-dehydrocholesterol reductase, the enzyme catalyzing the last step in cholesterol biosynthesis. The authors summarize the pathophysiology, epidemiology, clinical picture, diagnostics and therapy of the disease based on a review of the international literature. Since 2004, fourteen patients have been diagnosed with Smith-Lemli-Opitz syndrome in Hungary, which suggests an underdiagnosis of the disease based upon estimated incidence data. Due to deficiency of the 7-dehydrocholesterol reductase, serum cholesterol concentration is low and 7-dehydrocholesterol concentration is elevated in blood and tissues; the latter being highly specific for the syndrome. Detection of disease-causing mutations makes the prenatal diagnosis possible. The clinical spectrum is wide, the most common symptom is syndactyly of the second and third toes. Standard therapy is cholesterol supplementation. Recent publications suggest that oxidative compounds of 7-dehydrocholesterol may play a role in the pathophysiology of the disease as well.

[Pneumatic tube system for transport of laboratory samples: preanalytical aspects]. / Preanalitikai szempontok pneumatikus csopostával szállított laboratóriumi minták esetén.

INTRODUCTION: A considerable proportion of laboratory errors occurs in the preanalytical phase. AIM: The aims of the authors were to study preanalytical errors in routine and emergency laboratory diagnostics in a regional clinical laboratory and evaluate the effect of the pneumatic tube system on turnaround time and laboratory results. METHOD: The ratio of preanalytical errors and reasons of test rejection were analysed. In addition, the effects of pneumatic tube and manual transport on the occurrence of hemolysis and platelet activation were compared. RESULTS: Using the pneumatic tube transport system, preanalytical error was below 1%. The main causes of test rejection were haemolysis in case of serum samples, and clot formation and citrate excess in anticoagulated samples. The pneumatic tube transport resulted in significantly faster sample transport, more equalized sample arrival and processing, hence the turnaround time became shorter both for routine and emergency tests. CONCLUSIONS: Autovalidation and proper control of preanalytical errors are essential for rapid and reliable laboratory service supported by the pneumatic tube system for sample transport.

Relation between biomarkers and clinical severity in patients with Smith-Lemli-Opitz syndrome.

UNLABELLED: Smith-Lemli-Opitz syndrome (SLOS), a multiple congenital anomaly with severe mental retardation, is caused by decreased activity of 7-dehydrocholesterol reductase. Fifteen Hungarian patients were diagnosed with SLOS on the basis of clinical symptoms, serum cholesterol, 7-dehydrocholesterol, and molecular genetic testing. Their age at the time of diagnosis in mild SLOS (n = 4, clinical score <20) was 0.5-18 years, cholesterol was 2.37 ± 0.8 mmol/L, and 7DHC was 0.38 ± 0.14 mmol/L. In the group of typical SLOS (n = 7, score 20-50), the diagnosis was set up earlier (age of 0.1-7 years); t-cholesterol was 1.47 ± 0.7 mmol/L, and 7DHC was 0.53 ± 0.20 mmol/L. Patients with severe SLOS (n = 4, clinical score > 50) died as newborns and had the lowest t-cholesterol (0.66 ± 0.27 mmol/L), and 7DHC was 0.47 ± 0.14 mmol/L. Correlation coefficient with clinical severity was 0.74 for initial t-cholesterol and 0.669 for Cho/7DHC. Statistically significant difference was between the initial t-cholesterol of mild and severe SLOS (p = 0.01), and between the Cho/7DHC ratios of groups (p = 0.004). In severe SLOS, the percentage of α-lipoprotein was significantly lower than in typical (p = 0.003) and mild SLOS (p = 0.004). Although serum albumin, total bilirubin, and hemostasis parameters remained in the reference range during cholesterol supplementation (n = 10) combined with statin therapy (n = 9), increase of aspartate aminotransferase and alanine aminotransferase in 50 % of the patients probably refers to a reversible alteration of liver function; therefore, statin therapy was suspended. CONCLUSION: life expectancy is fundamentally determined by the initial t-cholesterol, but dehydrocholesterol and α-lipoprotein have prognostic value. Accumulation of hepatotoxic DHC may inhibit the synthesis of α-lipoproteins, decreasing the reverse cholesterol transport. During statin therapy, we suggest monitoring of lipid parameters and liver function.

Fluvastatin-induced alterations of skeletal muscle function in hypercholesterolaemic rats.

Although statins, the most widely used drugs in the treatment of hyperlipidaemia, are generally accepted as efficient and safe drugs their side-effects on skeletal muscle have been reported with increasing frequency. The lack of an animal model in which these side effects would consistently be observed is one of the important drawbacks in studying statin associated myopathy. To overcome this and enable the studying of the effects of fluvastatin on skeletal muscles an animal model with high blood cholesterol levels was developed. In these animals cholesterol levels rose more than seven fold (from 1.5 ± 0.1 to 10.7 ± 2.0 mmol/l; n = 15 and 16) with a dramatic increase in low density lipoprotein/high density lipoprotein ratio (from 0.29 ± 0.02 to 1.56 ± 0.17). While the latter was reversed by statin treatment, an elevation in blood creatine kinase (CK) level indicated the presence of muscle wasting. Fibers from m. extensor digitorum longus (EDL) showed significant reduction in cross sectional area in the statin treated groups. Statin treatment also decreased the proliferation and fusion of skeletal myotubes in culture. In line with this, resting intracellular calcium concentration ([Ca(2+)](i)) was reduced in statin treated satellite cells and myotubes. On the other hand, in adult skeletal muscle fibers statin treatment increased resting [Ca(2+)](i) (116 ± 4 nM vs. 151 ± 5 nM; n = 33 and 34) and decreased both twitch and tetanic force both in EDL and m. soleus. In addition, in m. soleus the duration of twitch and tetanic force was shortened. These results clearly indicate that statin administration in these animals results in a myopathy characterized by decreased muscle force and elevated plasma CK level.

Monitoring of mycophenolic acid and kidney function during combined immunosuppressive therapy.

BACKGROUND: Mycophenolic acid (MPA), a selective inhibitor of lymphocyte proliferation, has lately been used to improve renal function and prolong graft survival in renal transplanted patients. Still, there is no consensus considering the recommended dosing and the therapeutic range of MPA. METHODS: To estimate the safe therapeutic range of MPA, its plasma level and indicators of kidney function were measured in 216 patients (138 male, 78 female, age 46 ± 12 years) 67 ± 46 months after transplantation. Besides MPA, patients received cyclosporine (Group A, n=122) or tacrolimus (Group B, n=77). Seventeen patients (Group C) were treated with MPA in combination with everolimus or sirolimus. Plasma MPA was measured by enzyme inhibition assay. RESULTS: In the whole study group MPA level increased with the dose of MPA (p=0.013). MPA level was below the therapeutic range in 40% (Group A) and 45% (Group B) of patients, respectively. MPA was 1.9 ± 1.56 mg/L in Group A, 2.4 ± 1.69 mg/L in Group B. In Group A MPA level increased and cyclosporine decreased with the progress of renal disease. CONCLUSIONS: Increasing MPA/cyclosporine ratio at more severe stages of chronic kidney disease was tolerable for the patients and rejection could be avoided. Tubular damage detected by urinary N-acetyl-ß-D-glucosaminidase did not correlate with the MPA level.

[Interpretation of highly sensitive troponin assays: acute or chronic myocardial damage?]. / Nagy érzékenységu troponintesztek értékelése: akut vagy krónikus szívizom-károsodás?

UNLABELLED: Troponin is the first choice in the diagnosis of acute myocardial infarction. Correct interpretation is challenging, because high sensitive troponin tests used today detect even the smallest cardiac damage. METHODS: High sensitive troponin T (Roche) and troponin I (Mitsubishi Pathfast) and creatine-kinase activity were measured in 20 patients, each having two samples with the time lapse 3-9 hours. RESULTS: In the group without acute myocardial infarction (n = 10) no significant increase in creatine-kinase and creatine-kinase-MB levels were seen, and the mild raise of troponins was due to other cardiovascular problems (atrial fibrillation, paroxysmal supraventricular tachycardia). With acute myocardial infarction (n = 10) a dramatic increase of troponin levels was found in the second samples, and also an increase of creatine-kinase and creatine-kinase-MB activity. According to Fischer-probe a twofold or higher increase of troponin implies 19-times higher risk of acute myocardial infarction in the case of troponin T and 8-times odds ratio at troponin I. CONCLUSIONS: The patient's accompanying diseases should always be considered. If the troponin level is elevated, the measurement should be repeated within 3-6 hours. When troponin shows at least a twofold increase and the patient has chest pain or positive ECG, AMI is likely, and the patient needs special medical care. Although the first troponin level might be elevated if accompanying diseases cause chronic cardiac damage, it can be differentiated by a second troponin measurement.

A patient with Smith-Lemli-Opitz syndrome: novel mutation of the DHCR7 gene and effects of therapy with simvastatin and cholesterol supplement.

BACKGROUND: The Smith-Lemli-Opitz (SLO) syndrome is a multiple congenital anomaly with mental retardation due to a decreased or lack of activity of 7-dehydrocholesterol reductase as a consequence of mutations of the DHCR7 gene. This paper describes a special patient with SLO syndrome. Laboratory examination showed low cholesterol (2.77 mmol/L) and increased 7-dehydrocholesterol level (102 mg/L). Molecular genetic analysis revealed a compound heterozygosity c.964-1G>C/p.G366V (c.G1370T) of the proband. The p.G366V is a novel mutation of the DHCR7 gene with guanine by thymine nucleotide exchange resulting in glycin by valin amino acid exchange in the dehydrocholesterol reductase enzyme. Simvastatin (0.2 mg/kg/day) and cholesterol replacement therapy (150-250 mg/kg/day) led to significant improvement in the patient's laboratory findings (7-dehydrocholesterol, cholesterol) as well as in his behavior and gross motor function. CONCLUSION: Our patient demonstrates that the c.964-1G>C/p.G366V (c.G1370T) genotype of combined heterozygosity is associated with a typical form of SLO syndrome along with moderately altered laboratory findings and a favorable biochemical response to cholesterol and simvastatin treatment.

Hepatobiliary response in postoperative lipid therapy in gastrointestinal surgery.

BACKGROUND/AIMS: Intravenous lipid emulsions may contribute to the development of total parenteral nutrition (TPN)--induced hepatobiliary complications. METHODS: In a prospective, randomised setting the authors compared the short-term hepatic effects of medium-chain triglycerides/short-chain triglycerides (MCT/LCT) physical mixture with a four-component intravenous (i.v.) lipid emulsion (LCT, MCT, Olive-oil and Fish-oil) in patients undergoing elective gastrointestial surgery during the early postoperative period. RESULTS: The authors demonstrated that total and conjugated bilirubin, alkaline phosphatase, alanine aminotransferase, aspartate amino transferase and cholinesterase did not change significantly during the 5-days observation period. In contrast to this, gamma-glutamyl transferase (GGT) activity increased by 2,4 times during 5-days therapy with the lipid emulsions mentioned above (SMOF lipid: 21,9 to 52,9 U/L, Lipofundin: from 32,5 to 79,6 U/L). CONCLUSION: during a 4-days administration hepatic effect of the intravenous lipid emulsions did not differ significantly. The changes in enzyme levels confirm the cholestatic type of hepatobiliary deviations without clinical impact on short-term TPN therapy.

Detection of haemolysis, a frequent preanalytical problem in the serum of newborns and adults.

BACKGROUND: Preanalytical problems can be more frequent in case of preterm and term newborns as compared to the general patient population. Here we present the leading preanalytical errors in our laboratory, the prevalence of haemolysis and its impact on laboratory test results, and our efforts to improve the diagnostic workup of newborns' samples. METHODS: Preanalytical quality indicators were analysed in all samples in 2018. The haemolysis index was measured spectrophotometrically in serum samples in the period of 2012-2018, and the ratio of haemolysed samples and the test rejection rates were analysed. The data of newborns and other patients were analysed separately. RESULTS: During the tested year, the leading preanalytical errors were haemolysis in serum samples, inadequate sample identification and clotting of anticoagulated blood regarding all samples or newborns. In this seven-year period the ratio of haemolysed serum samples was 4.00% in all patients and 46.4% in newborns, while the test rejection rates due to haemolysis were 0.57% and 3.71%, respectively. Haemolysis indices were significantly higher in case of newborns than in patients with documented severe intravascular haemolysis which suggests that the major reason of elevated haemolysis indices in newborns was in vitro haemolysis. Accordingly, all C-reactive protein (CRP) results which were rejected by severe haemolysis became reliable after repeating blood sampling. CONCLUSION: Haemolysis is the leading preanalytical problem not only in newborns but also in the general patient population. Our study highlights the importance of automated assessment of serum indices and continuous monitoring of the preanalytical quality indicators and suggests the need for education and blood collection trainings.

Intracardiac Fibrinolysis and Endothelium Activation Related to Atrial Fibrillation Ablation with Different Techniques.

OBJECTIVE: The effect of pulmonary vein isolation (PVI) on fibrinolytic and endothelial activation with currently applied periprocedural anticoagulation has not been explored. We measured markers of fibrinolysis and endothelium activation before and after PVI with the second-generation cryoballoon (Cryo), pulmonary vein ablation catheter (PVAC-Gold), and irrigated radiofrequency (IRF). METHODS: Markers of fibrinolysis and endothelium activation in left atrial (LA) blood samples were measured in 31 patients before and after PVI (Cryo:10, PVAC-Gold: 7, IRF: 14). Periprocedural anticoagulation included uninterrupted vitamin K antagonist and iv heparin (ACT≥300 sec) during LA dwelling. RESULTS: Levels of D-dimer (median; interquartile range, mgFEU/L) increased with all techniques (PVAC: 0.34; 0.24-0.50 versus 0.70; 0.61-1.31; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; PAP complex level (ng/ml) increased after Cryo (247.3, 199.9-331.6 versus 270.9, 227.9-346.7; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; PAI-1 activity (%) decreased with the PVAC (1.931; 0.508-3.859 versus 0.735, 0.240-2.707; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; VWF antigen levels and FVIII activity increased after PVI with all the 3 techniques. The levels of soluble VCAM-1 (ng/ml) did not change after PVAC procedures, but increased after Cryo (542, 6; 428.5-753.1 versus 619.2; 499.8-799.0; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93; p=0.0313, Cryo: 0.33; 0.28-0.49 versus 0.79; 0.65-0.93. CONCLUSION: PVI with contemporary ablation techniques and periprocedural antithrombotic treatment induces coagulation and endothelium activation of similar magnitude with different ablation methods.

[Challenge and limitations in determination of serum creatinine]. / A szérumkreatinin-meghatározás kihívásai és korlátai.

Since 2006 clinical guidelines have recommended that the estimated glomerular filtration rate should be calculated from serum creatinine for the early detection of chronic kidney disease. These brought into the limelight the limitations of the Jaffe method and for comparability of test results the different routine creatinine methods need to be harmonized. The disadvantage of the kinetic Jaffe creatinine determination is its low specificity. This was improved by the enzymatic, compensated-Jaffe and high resolution liquid chromatographic assays introduced in the last decade. Creatinine values determined by the new methods are more accurate, but give lower creatinine values, therefore the glomerular filtration rate would be overestimated, if the new creatinine results were applied in the previous formulae (4-variables Modification of Diet in Renal Disease-186, Cockcroft-Gault, Quadratic). Because of the new creatinine methods estimation of the glomerular filtration rate and classification in chronic kidney disease staging became uncertain. Therefore the 4-variables Modification of Diet in Renal Disease-186 formula has been adjusted in 2006 and for the new creatinine methods (traceable to the isotope-dilution mass spectrometry) only the new Modification of Diet in Renal Disease-175 formula is advised. Authors compare the diagnostic value and limitations of the creatinine methods.

[Biochemical alterations in patients with Down syndrome]. / Biokémiai eltérések Down-szindromás betegekben.

UNLABELLED: Down syndrome is a chromosome abnormality with specific clinical symptoms and mental retardation caused by trisomy of chromosome 21. The basic genetic change cannot be cured, the control of the associated symptoms, however, may improve the patients' quality of life. AIMS: Authors studied the possible correlations between the Down-specific genes and the related biochemical changes. Expression of superoxide dismutase, cystathionine-beta-synthase and S100 protein was investigated. Further aim of the study was to determine the total serum antioxidant capacity (transferrin, ferritin, total protein, albumin and bilirubin) along with the extracellular antioxidants as well as concentrations of homocysteine, folic acid, and vitamin B 12 . To assess the vascular damage, the activity of NAG and S100B level was measured. METHODS: Standard laboratory methods were used to determine the antioxidant capacity (Stocks, 1974), homocysteine (HPLC), folic acid (capture, IMX-Abbott), vitamin B 12 (MEIA, IMX-Abbott), S100 B protein (chemiluminescence sandwich immunoassay) levels, and N-acetyl-beta-D-glucosaminidase (spectrophotometry). RESULTS: Plasma homocysteine value proved to be lower in 7 of the 30 and higher in 6 of the 30 patients studied than the reference range. Plasma homocysteine was found 95 +/- 21% of the reference value. Relative value of plasma folic acid - expressed in percent of the normal value - was 85 +/- 51%, and that of B 12 was 78 +/- 30%. Deficiency of folic acid was detected in 2 of the 30, decreased level of B 12 in 2 of the 30 patients enrolled. No difference was found in antioxidant activity values between Down syndrome patients and healthy controls, however, neither of them reached the adult reference range. S100 protein concentration of 4-8 times higher values (average value: 0.68 +/- 0.27 microg/l) than upper limit of the reference range was observed (> 1 year: > 0.15 microg/l). Mean value of serum N-acetyl-beta-D-glucosaminidase remained within the reference range (10-30 U/l). No statistically significant correlation between the antioxidant activity and N-acetyl-beta-D-glucosaminidase values could be observed. CONCLUSION: The lower homocysteine, folic acid and B 12 values may be considered as the consequence of an increased cystathionine-beta-synthase activity ("atheroma free model"). There was no significant alteration in antioxidant activity level. It can be supposed that the hydrogene peroxide produced due to increased expression of superoxide dismutase is metabolized by the induced glutathione-peroxidase and catalase keeping by this the balance of the antioxidant system. This hypothesis is supported by the normal N-acetyl-beta-D-glucosaminidase values not indicating any vascular damage. The high S100 values, however, reflect certain brain damage which shows a progress with the age. Based on these experiences, regular control of these parameters is recommended. Furthermore authors think that folic acid supplementation is indicated in order to improve the patients' learning capacity, inhibit the development of Alzheimer symptoms and improve the quality of life.

[The epidemic of chronic kidney disease requires the estimation of glomerular filtration rate]. / Az idült vesebetegség epidémiája szükségessé teszi a glomerulus filtrációs ráta számítását.

Nowadays chronic kidney disease has become a major public health problem due to the great increase in atherogenic nephropathies. In the absence of classic renal symptoms, chronic kidney disease is mostly diagnosed when renal failure is already advanced, although it can be revealed by laboratory tests in the earlier stages. When diagnosis is late, the progression to end-stage renal failure is unavoidable and renal replacement therapy is needed. Even early-moderate renal failure significantly increases the risks for atherosclerosis, thereby leading to the deaths of patients from cardiovascular disease before initiation of dialysis. Therefore screening for asymptomatic chronic kidney disease is urgently needed. Estimated glomerular filtration rate has the greatest importance in the screening and in the timely intervention to slow down the progression of renal failure and cardiovascular disease. In 2005, the Hungarian Society of Nephrologists and the Hungarian Society of Laboratory Medicine suggested the automatic estimation and reporting of glomerular filtration rate, each time serum creatinine measurements were made. This practice is used more frequently by laboratories in Hungary. This article aims to help facilitate the utilization and evaluation of estimated glomerular filtration rate.

Temporal walk based centrality metric for graph streams.

A plethora of centrality measures or rankings have been proposed to account for the importance of the nodes of a network. In the seminal study of Boldi and Vigna (2014), the comparative evaluation of centrality measures was termed a difficult, arduous task. In networks with fast dynamics, such as the Twitter mention or retweet graphs, predicting emerging centrality is even more challenging. Our main result is a new, temporal walk based dynamic centrality measure that models temporal information propagation by considering the order of edge creation. Dynamic centrality measures have already started to emerge in publications; however, their empirical evaluation is limited. One of our main contributions is creating a quantitative experiment to assess temporal centrality metrics. In this experiment, our new measure outperforms graph snapshot based static and other recently proposed dynamic centrality measures in assigning the highest time-aware centrality to the actually relevant nodes of the network. Additional experiments over different data sets show that our method perform well for detecting concept drift in the process that generates the graphs.

Anthracycline antibiotics induce acute renal tubular toxicity in children with cancer.

Experimental evidence suggests that anthracyclines, widely used in cancer chemotherapy, may impair kidney function. We assessed kidney function by serum creatinine, urinary N-acetyl-beta-D-glucosaminidase activity indices (NAGi) and microalbuminuria (MA) in 160 serum and urine samples obtained from 66 children with cancer. The effect of dexrazoxane was analyzed in 6 children on dexrazoxane supportive therapy in conjunction with daunorubicin (DNR) treatment, as compared with 6 children not receiving this agent. NAGi was significantly (p<0.05) elevated after treatment by DNR, doxorubicin, epirubicin (EPI) and idarubicin (IDA). MA proved to be a less sensitive indicator of kidney damage than NAGi. DNR resulted in a progressive deterioration of proximal tubular function as determined by linear regression analysis. The mean NAGi in the dexrazoxanetreated group was significantly (p<0.005) lower than in children not receiving dexrazoxane prior to DNR treatment. In conclusion, our study demonstrated that DNR, EPI and IDA induced an acute renal tubular damage similar to known tubulotoxic agents as cisplatin, carboplatin, cyclophosphamide and ifosfamide. The damage was clinically mild and only a minor proportion of patients can be expected to develop long-lasting tubulopathy with negative impact on the quality of life.

Identification of sulfhemoglobinemia after surgical polypectomy.

Sulfhemoglobinemia (SHb) is an uncommon cause of cyanosis that is predominantly drug-induced in adults. We report an unusual case of sodium sulfate-induced sulfhemoglobinemia in a 61-year-old woman after surgical polypectomy. Fractional hemoglobin derivates were assayed by spectrophotometry and high-performance liquid chromatography. The SHb ratio was 8.6% in the first sample and 3.77% a month later measured by spectrophotometry. In the blood hemolysate, a new peak was identified as SHb with high-performance liquid chromatography (HPLC). HPLC showed the presence of 9.37% SHb in the first sample and 4.88% a month later. After removing the suspected toxic agent the cyanosis decreased significantly. The findings underline the importance of routine SHb detection in cyanosis of unknown origin especially in emergency cases.