Detection of acute kidney injury in premature asphyxiated neonates by serum neutrophil gelatinase-associated lipocalin (sNGAL) – sensitivity and specificity of a potential new biomarker

Introduction

Acute kidney injury (AKI) is common in neonatal intensive care units (NICU). In recent years, every effort is made for early detection of AKI. Our hypothesis was that serum neutrophil gelatinase-associated lipocalin (sNGAL) may be a reliable screening test for early diagnosis of AKI in premature neonates after perinatal asphyxia. Therefore, our aim was to assess the diagnostic accuracy of sNGAL for AKI in premature asphyxiated neonates.

Materials and methods

AKI was defined in the third day of life (DOL 3) as a serum creatinine (sCr) increase ≥ 26.5 μmol/L from baseline (the lowest previous sCr). According to the increase of sCr, AKI patients were divided in AKIN1 (sCr increase up to 1.9 baseline) and AKIN2 (sCr increase from 2.0 to 2.9 baseline). sNGAL levels were measured on DOL 1, 3 and 7.

Results

AKI was diagnosed in 73 (0.676) of 108 enrolled premature asphyxiated neonates. Sixty one patients (0.836) were classified in AKIN1 and 12 patients (0.164) in AKIN2. sNGAL reached the maximal concentrations on DOL 1 within 4 hours after admission to NICU, being higher in AKI compared with no-AKI group (160.8 ± 113.1 vs. 87.1 ± 81.6; P < 0.001) as well as in AKIN2 compared with AKIN1 group (222.8 ± 112.9 vs. 147.8 ± 109.9; P < 0.001). The best areas under the receiver operating characteristic curves (AUC) for prediction of AKI were 0.72 [95% (0.62-0.80) P < 0.001] on DOL1 at 2h and 0.72 [95% (0.63-0.80) P < 0.001] at 4th hour after admission respectively. The corresponding sNGAL cutoff concentrations were 84.87 ng/mL (sensitivity 69.0% and specificity 71.9%) and 89.43 ng/mL (sensitivity 65.7% and specificity 74.3%).

Conclusions

In premature asphyxiated neonates sNGAL measured within the first 4 hours of DOL 1 is predictive of the occurrence and severity of AKI. Therefore, plasma levels of NGAL may be used for early diagnosis of AKI in these patients.Key words: serum neutrophil gelatinase-associated lipocalin, acute kidney injury, premature neonates, biomarker     

Electronic detection of dielectrophoretic forces exerted on particles flowing over interdigitated electrodes

Dielectric particles flowing through a microfluidic channel over a set of coplanar electrodes can be simultaneously capacitively detected and dielectrophoretically (DEP) actuated when the high (1.45 GHz) and low (100 kHz–20 MHz) frequency electromagnetic fields are concurrently applied through the same set of electrodes. Assuming a simple model in which the only forces acting upon the particles are apparent gravity, hydrodynamic lift, DEP force, and fluid drag, actuated particle trajectories can be obtained as numerical solutions of the equations of motion. Numerically calculated changes of particle elevations resulting from the actuation simulated in this way agree with the corresponding elevation changes estimated from the electronic signatures generated by the experimentally actuated particles. This verifies the model and confirms the correlation between the DEP force and the electronic signature profile. It follows that the electronic signatures can be used to quantify the actuation that the dielectric particle experiences as it traverses the electrode region. Using this principle, particles with different dielectric properties can be effectively identified based exclusively on their signature profile. This approach was used to differentiate viable from non-viable yeast cells (Saccharomyces cerevisiae).     

Paraoxonase 1 activity and phenotype distribution in premenopausal and postmenopausal women

Introduction

Postmenopausal women have higher risk of cardiovascular disease. One of the contributing factors could be reduced activity of anti-atherogenic enzyme paraoxonase 1 (PON1). The aim of this study was to examine differences in the lipid status, paraoxonase and arylesterase PON1 activities and PON1 phenotype in women with regular menstrual cycle and in postmenopausal women.

Materials and methods:

The study included 51 women in reproductive age (25 in follicular and 26 in luteal phase of the menstrual cycle) and 23 women in postmenopause. Lipid parameters in sera were determined using original reagents and according to manufacturer protocol. PON1 activity in serum was assessed by spectrophotometric method with substrates: paraoxon and phenylacetate. PON1 phenotype was determined by double substrate method.

Results:

Compared to the women in follicular and luteal phase, postmenopausal women have significantly higher concentration of triglyceride [0.9 (0.7–1.3), 0.7 (0.6–1.0) vs. 1.5 (0.9–1.7) mmol/L; P = 0.002], cholesterol [5.10 (4.78–6.10), 5.05 (4.70–5.40) vs. 6.30 (5.73–7.23) mmol/L; P < 0.001], LDL [3.00 (2.56–3.63), 3.00 (2.70–3.70) vs. 3.90 (3.23–4.50) mmol/L; P < 0.001], and apolipoprotein B [0.88 (0.75–1.00), 0.79 (0.68–1.00) vs. 1.07 (0.90–1.24) mmol/L; P = 0.002]. PON1 basal [104 (66–260), 106 (63–250) vs. 93 (71–165) U/L; P = 0.847] and salt-stimulated paraoxonase activity [210 (131–462), 211 (120–442) vs. 180 (139–296) U/L; P = 0.857] as well as arylesterase activity [74 (63–82), 70 (54–91) vs. 70 (60–81) kU/L; P = 0.906] and PON1 phenotype (P = 0.810) were not different in the study groups.

Conclusion:

There are no differences in PON1 activity and PON1 phenotype between women with regular menstrual cycle and postmenopausal women.     

The relations of parental supervision,parental school involvement,and child's social competence with school achievement in primary school

The aim of this study was to examine the relation of parental supervision, parental involvement at school and child's social competence with school achievement in primary school. A theoretical model was postulated that predicts direct and indirect effects of parental behaviors on adolescents’ school achievement. Participants were 1,024 adolescents attending Grades 5 through 8 in 20 primary schools in Croatia and one of their parents or guardians. Adolescents completed a scale assessing their self‐perceived social competence and data on their grade point average were collected. Parents completed scales measuring parental supervision and parental involvement at school and they rated their child's social competence. The results of model testing showed that parental behaviors have both direct and indirect effect on adolescents’ school achievement. Greater parental supervision and school involvement have a direct and an indirect, through their effects on child's social competence, positive effects on adolescents’ school achievement.     

The Influence of Interactive Learning Materials on Solving Tasks That Require Different Types of Mathematical Reasoning

International Journal of Science and Mathematics Education - The purpose of this study is to analyse the effects of the Interactive Learning Materials Triangle (iLMT) on the learning and knowledge...     

A new approach to evaluation of university teaching considering heterogeneity of students’ preferences

Students’ evaluations of teaching are increasingly used by universities to evaluate teaching performance. However, these evaluations are controversial mainly due to fact that students value various aspects of excellent teaching differently. Therefore, in this paper we propose a new approach to students’ evaluations of university teaching based on data from conjoint analysis. Conjoint analysis is a multivariate technique used to analyze the structure of individuals’ preference. In particular, our approach accounts for different importance students attach to various aspects of teaching. Moreover, it accounts explicitly for heterogeneity arising from students’ preferences, and incorporates it to form comprehensive teaching evaluation score. We have conducted survey and confirmed applicability and efficiency of the proposed approach.     

The positive attitude approach for teaching in higher education: An untrodden path for policy and practice

This article reports on a study in which a new conceptual framework for fostering a positive attitude towards teaching in higher education (PATTHE) was developed. The PATTHE framework builds on a holistic four-dimensional theoretical concept and is not limited by the specificity of teaching within a particular discipline or national higher education context. The four dimensions of PATTHE pertain to (a) emotional dimension, (b) professional development, (c) constructivist approaches to teaching, and (d) the teaching and research nexus; all of which are relevant for empowering quality teaching at personal, institutional and/or national higher education policy levels. The purpose of our study was to test and analyse this conceptual framework. Creative qualitative research methods were used including identification of keywords, evoking participant opinions through visual materials, reactions to vignettes, and by documenting discussions regarding the proposed PATTHE conceptual framework. A purposive and critically informed approach was used for the selection of twelve higher education experts as research participants. Responses from the selected education developers were collected through an online protocol system. Research results revealed that participant reflections on a positive attitude towards teaching showed a high level of agreement with the proposed conceptual framework; the proposed theoretical concept is thereby deemed well-constructed and acceptable with minimal extensions.     

Print Newspapers: Are They Still Being Used in Academic and Research Libraries?

A six-month print newspaper usage study at the University of Michigan's Hatcher Graduate Library showed a marked decrease in use from a more limited study done four years previously. In general, patrons used only the major national, international, and regional newspapers. Communications with other academic and research libraries confirm these findings.     

Citation Analysis to Assist Selection in Kinesiology

This article presents a citation analysis of articles published in 2011 from 11 kinesiology journals. The results of the citation analysis of 11 kinesiology journals are compared to a citation analysis of articles published in 2011 by faculty in the School of Kinesiology, University of Michigan. Comparing the four areas of kinesiology, Movement Science, Athletic Training, Sports Management, and Physical Education, the results show that articles published in Movement Science and Athletic Training cited a higher percentage of journal articles than articles published in Sports Management and Physical Education. While some of the materials cited went as far back as 1874, the mean age ranged from 1996 to 2004. Human Kinetics was the most cited publisher and the American Journal of Sports Medicine was the most cited journal. The University of Michigan Library owns 75% of the materials cited in the publications cited by School of Kinesiology faculty. Faculty in the School of Kinesiology cited many textbooks, a format not actively collected by the library before this analysis.     

Reporting of activated partial thromboplastin time (aPTT): Could we achieve better comparability of the results?

IntroductionActivated partial thromboplastin time (aPTT) is determined and reported as clotting time in seconds aPTT(s), but it is presumed that reporting results as patient-to-normal clotting time ratio, aPTT(r), could minimize within-laboratory variability. The aim of study was to investigate differences in reporting aPTT results that can affect comparability of the results among Croatian laboratories and suggest further steps for its harmonization.Materials and methodsThe questionnaire on aPTT reporting practice was distributed to 83 laboratories through Survey Monkey application in March 2019 as the part of the first regular round of Croatian Centre for Quality Assessment in Laboratory Medicine proficiency testing.ResultsThe survey response rate was 0.49. Majority of laboratories report aPTT results as both, seconds and ratio. Participants reported use of 23 different aPTT(s) reference intervals along with 17 different combinations of reagent/coagulometer and 25 aPTT(s) denominators of different origin for aPTT(r) calculation. Despite the same aPTT(s) results, the use of different denominators caused a dispersion of aPTT(r) results that can lead to exceeding external quality assessment performance criteria of 7%, particularly when results were compared for the same reagent group only. By applying aPTT(s) reference interval mean as denominator for calculation of aPTT(r) reference interval better concordance to harmonized one was obtained (17 vs. 27; χ² = 3.972; P = 0.046).ConclusionIn order to improve comparability of the results, laboratories are advised to use mean of aPTT(s) reference interval as denominator for aPTT(r) calculation. Type of coagulometer need to be considered when evaluating aPTT proficiency test results and its currently acceptable limit of performance evaluated accordingly.