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-β-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.

Background The aim of this study was to investigate the clinical and laboratory parameters that can predict the severity of Multisystem Inflammatory Syndrome in Children (MIS-C) at admission. Methods We conducted a single-center, partly retrospective, partly prospective, observational cohort study between November 1, 2020 and December 31, 2021, which included patients aged from 1 month to 19 years, meeting the diagnostic criteria of MIS-C. We categorized the patients into three subgroups based on clinical and laboratory markers and assessed the predictive value of these factors in terms of ICU administration and cardiac abnormalities. Results 53 patients were classified in the following subgroups: Kawasaki-like disease (group 1) (47.2%, n = 25), shock with or without acute cardiac dysfunction (group 2) (32%, n = 17), fever and inflammation (group 3) (20.8%, n = 11). Subgroup analysis revealed that patients with shock and KD at initial presentation had significantly more severe manifestation of MIS-C requiring intensive care unit (ICU) treatment. Of the initial laboratory values, only CRP showed a significant difference between the 3 clinical groups, being lower in group 3. 52.6% of patients were admitted to the ICU. The median length of ICU stay was 3 days (range 3–20). ICU admission was more likely in patients with shortness of breath, renal failure (AKI) and patients with significantly increased concentrations of ferritin, D-dimer, INR and significantly milder increase concentration of fibrinogen. We found that fibrinogen and ferritin levels are independent risk factors for ICU admission. Cardiac abnormalities were found in 56.6% of total (30/53), with the following findings: decreased left ventricular function (32%), coronary abnormality (11.3%), pericardial effusion (17%), arrhythmia (32.1%) and mitral regurgitation (26.6%). Diarrhea and conjunctivitis at the initial presentation with significantly elevated CRP, Pro-BNP and blood pH concentrations were found to be a potential predisposing factor for decreased cardiac function while Pro-BNP and pH were independent risk factors for MIS-C. Regardless of the initial symptoms of MIS-C, the outcome was generally favorable. Conclusions Clinical characteristics and baseline laboratory values ​​may help identify patients at increased risk for severe disease outcome, such as need for intensive care, presence of shock and decreased cardiac function. Trial registration Participation consent was not reqired and ethical considerations were unnecessary, since we did not perform any extra interventions, only the necessary and usual therapeutic and diagnostic methods were used.

Cheminformatics systems usually focus primarily on handling specific molecules and reactions. However, Markush structures are also indispensable in various areas, like combinatorial library design or chemical patent applications for the description of compound classes.The presentation will discuss how an existing molecule drawing tool (Marvin) and chemical database engine (JChem Base/Cartridge) are extended to handle generic features (R-group definitions, atom and bond lists, link nodes and larger repeating units, position and homology variation). Markush structures can be drawn and visualized in the Marvin sketcher and viewer, registered in JChem databases and their library space is searchable without the enumeration of library members. Different enumeration methods allow the analysis of Markush structures and their enumerated libraries. These methods include full, partial and random enumerations as well as calculation of the library size. Furthermore, unique visualization techniques will be demonstrated on real-life examples that illustrate the relationship between Markush structures and the chemical structures contained in their libraries (involving substructures and enumerated structures).Special attention will be given to file formats and how they were extended to hold generic features.

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Background Tumor lysis syndrome (TLS) and its most serious complication, acute kidney injury (AKI) are one of the emergency conditions in onco-hematology. It is difficult to predict the degree of kidney involvement. Therefore, we studied children with leukemia and lymphoma treated in four Hungarian tertiary centers (inpatient university clinics) retrospectively (2006–2016) from a nephrological aspect. Method Data of 31 pediatric patients were obtained from electronic- and paper-based medical records. Physical status, laboratory test results, treatments, and outcomes were assessed. Patients were analyzed according to both “traditional” TLS groupings, as laboratory TLS or clinical TLS, and nephrological aspect based on pRIFLE classification, as mild or severe AKI. Results Significant differences were found between the changes in parameters of phosphate homeostasis and urea levels in both classifications. Compared to age-specific normal phosphate ranges, before the development of TLS, hypophosphatemia was common (19/31 cases), while in the post-TLS period, hyperphosphatemia was observed (26/31 cases) most frequently. The rate of daily change in serum phosphate level was significant in the nephrological subgroups, but peaks of serum phosphate level show only a moderate increase. The calculated cut-off value of daily serum phosphate level increased before AKI was 0.32 mmol/L per ROC analysis for severe TLS–AKI. The 24-h urinalysis data of eight patients revealed transiently increased phosphate excretion only in those patients with TLS in whom serum phosphate was elevated in parallel. Conclusion Daily serum phosphate level increase can serve as a prognostic factor for the severity of pediatric TLS, as well as predict the severity of kidney involvement. Graphical abstract