Serum and urinary biomarkers for early detection of acute kidney injury following Hypnale spp. envenoming

BackgroundHump-nosed pit viper (HNV; Hypnale spp.) bites account for most venomous snakebites in Sri Lanka. Acute kidney injury (AKI) is the most serious systemic manifestation (1–10%) following HNV envenoming. We aimed to identify the value of functional and injury biomarkers in predicting the development of AKI early following HNV bites.MethodsWe conducted a prospective cohort study of patients with confirmed HNV envenoming presenting to two large tertiary care hospitals in Sri Lanka. Demographics, bite details, clinical effects, complications and treatment data were collected prospectively. Blood and urine samples were collected from patients for coagulation and renal biomarker assays on admission, at 0-4h, 4-8h, 8-16h and 16-24h post-bite and daily until discharge. Follow-up samples were obtained 1 and 3 months post-discharge. Creatinine (sCr) and Cystatin C (sCysC) were measured in serum and kidney injury molecule-1 (uKIM-1), clusterin (uClu), albumin (uAlb), β2-microglobulin (uβ2M), cystatin C (uCysC), neutrophil gelatinase associated lipocalin (uNGAL), osteopontin (uOPN) and trefoil factor-3 (uTFF-3) were measured in urine. Definite HNV bites were based on serum venom specific enzyme immunoassay. Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to stage AKI. Two patients had chronic kidney disease at 3 month follow-up, both with pre-existing abnormal sCr, and one developed AKI following HNV envenoming.ResultsThere were 52 patients with confirmed HNV envenoming; median age 48y (Interquartile range [IQR]:40-59y) and 29 (56%) were male. Median time to admission was 1.87h (IQR:1–2.75h). Twelve patients (23%) developed AKI (AKI stage 1 = 7, AKI stage 2 = 1, AKI stage 3 = 4). Levels of five novel biomarkers, the functional marker serum Cystatin C and the damage markers urinary NGAL, cystatin C, β2-microglobulin and clusterin, were elevated in patients who developed moderate/severe acute kidney injury. sCysC performed the best at 0–4 h post-bite in predicting moderate to severe AKI (AUC-ROC 0.95;95%CI:0.85–1.0) and no biomarker performed better than sCr at later time points.ConclusionssCysC appears to be a better marker than sCr for early prediction of moderate to severe AKI following HNV envenoming.     

Local scale DNA barcoding of bivalves (Mollusca): a case study

Divergence in cytochrome c oxidase 1 (COI), the genetic marker proposed for DNA barcoding, was investigated in marine bivalves from the genera Ennucula , Nucula , Yoldiella and Thyasira . No overlap in levels of intra- and interspecific variation was found. The levels of divergence found suggest that barcodes from COI will be useful in distinguishing between the species investigated in this study. The insufficiency of blast searches in GenBank to assign many of the obtained sequences to correct phylum was noted and clearly demonstrates the need for better search strategies specifically targeted at identification using DNA barcodes.     

A biochip platform for cell transfection assays

In this paper, we describe the development and characterization of a biochip platform for cell transfection assays. Silicon wafers were surface modified by plasma polymerization of allylamine plasma polymer (ALAPP) and grafting of a protein-resistant layer of poly(ethylene oxide) (PEO) on the plasma polymer surface. Excimer laser ablation was then used to pattern ALAPP-PEO coated samples for spatially controlled protein adsorption and subsequent cell attachment. X-ray photoelectron spectroscopy (XPS) was used to characterize the surface modifications before and after excimer laser ablation. Experiments confirmed the creation of a two-dimensionally controlled surface chemistry on the biochip. Cell culture experiments using human embryonic kidney (HEK 293) cells showed that cells attached exclusively to laser ablated areas. In addition, cells confined to ablated areas were successfully transfected with plasmid DNA containing the gene for green fluorescent protein (GFP). The cell transfection efficiencies of cells growing in a culture flask and cells confined on the biochip were determined to be 21 and 13%, respectively.     

Effects of 3-thia fatty acids on feed intake, growth, tissue fatty acid composition, beta-oxidation and Na+,K+-ATPase activity in Atlantic salmon

Atlantic salmon (Salmo salar) with an initial mass of 86 g were reared in 12 °C seawater for 8 weeks to a final average mass of 250 g. The fish were fed fish meal and fish oil-based diet supplemented with either 0%, 0.3% or 0.6% of tetradecylthioacetic acid (TTA), a 3-thia fatty acid. The specific growth rate (SGR) decreased with increasing dietary dose of TTA. The SGR of the group fed 0% of TTA (Control) was 1.8; that of the group fed 0.3% of TTA (TTA-L) was 1.7, and that of the group fed 0.6% of TTA (TTA-H) was 1.5. The mortality increased with increased dietary dose of TTA. The mitochondrial β-oxidation capacity in the liver of fish fed the TTA diets was 1.5 to 2 times higher than that of the Control fish. TTA supplementation caused substantial changes in the fatty acid compositions of the phospholipids (PL), triacylglycerols (TAG) and free fatty acids (FFA) of gills, heart and liver. The percentages of n−3 fatty acids, particularly 22:6 n−3, increased in fish fed diets containing TTA, while the percentage of the saturated FAs 14:0 and 16:0 in the PL fractions of the gills and heart decreased. The sum of monounsaturated FAs in the PL and TAG fractions from liver was significantly higher in fish fed diets containing TTA. TTA itself was primarily incorporated into PL. Two catabolic products of TTA (sulphoxides of TTA) were identified, and these products were particularly abundant in the kidney. TTA supplementation had no significant effect on the activity of the membrane-bound enzyme Na⁺,K⁺-ATPase.     

Kinetic Estimation of GFR Improves Prediction of Dialysis and Recovery after Kidney Transplantation

BackgroundThe early prediction of delayed graft function (DGF) would facilitate patient management after kidney transplantation.MethodsIn a single-centre retrospective analysis, we investigated kinetic estimated GFR under non-steady-state conditions, KeGFR, in prediction of DGF. KeGFR_sCr was calculated at 4h, 8h and 12h in 56 recipients of deceased donor kidneys from initial serum creatinine (sCr) concentrations, estimated creatinine production rate, volume of distribution, and the difference between consecutive sCr values. The utility of KeGFR_sCr for DGF prediction was compared with, sCr, plasma cystatin C (pCysC), and KeGFR_pCysC similarly derived from pCysC concentrations.ResultsAt 4h, the KeGFR_sCr area under the receiver operator characteristic curve (AUC) for DGF prediction was 0.69 (95% CI: 0.56–0.83), while sCr was not useful (AUC 0.56, (CI: 0.41–0.72). Integrated discrimination improvement analysis showed that the KeGFR_sCr improved a validated clinical prediction model at 4h, 8h, and 12h, increasing the AUC from 0.68 (0.52–0.83) to 0.88 (0.78–0.99) at 12h (p = 0.01). KeGFR_pCysC also improved DGF prediction. In contrast, sCr provided no improvement at any time point.ConclusionsCalculation of KeGFR from sCr facilitates early prediction of DGF within 4 hours of renal transplantation.     

Persistently elevated extracellular HSP70 (HSPA1A) level as an independent prognostic marker in post-cardiac-arrest patients

Predicting the prognosis of comatose, post-cardiac-arrest patients is a complex problem in clinical practice. There are several established methods to foretell neurological outcome; however, further prognostic markers are needed. HSP70 (HSPA1A), which increases rapidly in response to severe stress (among others after ischemic or hypoxic events), is a biomarker of cell damage in the ischemic brain and spinal cord. We hypothesized that HSP70 might be a reliable predictor of mortality in post-cardiac-arrest patients. The aim of this study was to analyze the role of extracellular HSP70 in the systemic inflammatory response over time, as well as the predictive value in cardiac arrest patients. Here, we show that the elevation of HSP70 levels in resuscitated patients and their persistence is an independent predictor of 30-day mortality after a cardiac arrest. Forty-six cardiac arrest patients were successfully cooled to 32–34 °C for 24 h, and followed up for 30 days. Twenty-four patients (52.2 %) were alive by the end of follow-up, and 22 patients (47.8 %) died. Forty-six patients with stable cardiovascular disease served as controls. Extracellular HSP70 (measured by ELISA in blood samples) was elevated in all resuscitated patients (1.31 [0.76–2.73] and 1.70 [1.20–2.37] ng/ml for survivors and non-survivors, respectively), compared with the controls (0.59 [0.44–0.83] ng/ml). HSP70 level decreased significantly in survivors, but persisted in non-survivors, and predicted 30-day mortality regardless of age, sex, complications, and the APACHE II score. Extracellular HSP70 could prove useful for estimating prognosis in comatose post-cardiac-arrest patients.