Intercorrelated variability in blood and hemodynamic biomarkers reveals physiological network in hemodialysis patients.

Increased intra-individual variability of a variety of biomarkers is generally associated with poor health and reflects physiological dysregulation. Correlations among these biomarker variabilities should then represent interactions among heterogeneous biomarker regulatory systems. Herein, in an attempt to elucidate the network structure of physiological systems, we probed the inter-variability correlations of 22 biomarkers.

Synchrony of biomarker variability indicates a critical transition: Application to mortality prediction in hemodialysis.

Critical transition theory suggests that complex systems should experience increased temporal variability just before abrupt state changes. We tested this hypothesis in 763 patients on long-term hemodialysis, using 11 biomarkers collected every two weeks and all-cause mortality as a proxy for critical transitions. We find that variability-measured by coefficients of variation (CVs)-increases before death for all 11 clinical biomarkers, and is strikingly synchronized across all biomarkers: the first axis of a principal component analysis on all CVs explains 49% of the variance.

Prediction of Mortality in Hemodialysis Patients Using Moving Multivariate Distance.

There is an increasingly widespread use of biomarkers in network physiology to evaluate an organism's physiological state. A recent study showed that albumin variability increases before death in chronic hemodialysis patients. We hypothesized that a multivariate statistical approach would better allow us to capture signals of impending physiological collapse/death.

Estimation of homeostatic dysregulation and frailty using biomarker variability: a principal component analysis of hemodialysis patients.

Increased intraindividual variability in several biological parameters is associated with aspects of frailty and may reflect impaired physiological regulation. As frailty involves a cumulative decline in multiple physiological systems, we aimed to estimate the overall regulatory capacity by applying a principal component analysis to such variability. The variability of 20 blood-based parameters was evaluated as the log-transformed coefficient of variation (LCV) for one year's worth of data from 580 hemodialysis patients.

Aging and death-associated changes in serum albumin variability over the course of chronic hemodialysis treatment.

Background: Several epidemiological studies have demonstrated associations between variability in a number of biological parameters and adverse outcomes. As the variability may reflect impaired homeostatic regulation, we assessed albumin variability over time in chronic hemodialysis (HD) patients.

Methods: Data from 1346 subjects who received chronic HD treatment from May 2001 to February 2015 were analyzed according to three phases of HD treatment: post-HD initiation, during maintenance HD treatment, and before death.

Variability of laboratory parameters is associated with frailty markers and predicts non-cardiac mortality in hemodialysis patients.

Background: The levels of many laboratory parameters are associated with the outcomes of dialysis patients, but the significance of their variability has not been well studied.

Methods: A total of 384 patients receiving stable hemodialysis treatment during 2002 were followed up for mortality until the end of 2013. The within-patient coefficients of variation (CV) were calculated for 13 laboratory parameters from 1 year of data.

Prerenal uremia induced by severe diarrhea due to colon adenoma: a case of McKittrick-Wheelock syndrome in an elderly patient.

McKittrick-Wheelock syndrome can be successfully treated by emergent dialysis, prescription of bicarbonate, and endoscopic submucosal dissection, which allow elderly people suffering from this syndrome to maintain their activities of daily living. In patients with this syndrome, a large colonic villous adenoma secretes excessive amounts of mucus and causes severe electrolyte depletion and dehydration. An 81-year-old man who had been suffering from chronic renal failure (creatinine 256.

(Pro)renin receptor-mediated activation of mitogen-activated protein kinases in human vascular smooth muscle cells.

Blockade of (pro)renin receptor has benefits in diabetic angiotensin II type-1a-receptor-deficient mice, suggesting the importance of (pro)renin receptor-mediated intracellular signals. To determine the mechanism whereby the human (pro)renin receptor activates mitogen-activated protein kinases in human vascular smooth muscle cells (hVSMC), we treated the cells with recombinant human prorenin. Prorenin enhanced hVSMC proliferation and activated extracellular-signal-related protein kinase (ERK) in a dose- and time-dependent manner but did not influence activation of p38 or c-Jun NH(2)-terminal kinase.

Left-right asymmetry in the alimentary canal of the Drosophila embryo.

In many animal groups, left-right (LR) asymmetry within the body is observed. The left and right sides of the body are generally defined with reference to the anterior-posterior (AP) and dorsal-ventral (DV) axes. In this study, we investigated whether LR asymmetry is solely dependent on the AP and DV polarities in Drosophila embryos.

Oxidative stress induced by iron released from transferrin in low pH peritoneal dialysis solution.

Background: Transferrin binds extracellular iron and protects tissues from iron-induced oxidative stress. The binding of iron and transferrin is pH dependent and conventional peritoneal dialysis (PD) solutions have unphysiologically low pH values. Herein, we investigated whether conventional PD solution releases iron from transferrin and if the released iron causes oxidative stress.

Calcification and osteopontin localization in the peritoneum of patients on long-term continuous ambulatory peritoneal dialysis therapy.

Background: Peritoneal calcification is an uncommon complication of continuous ambulatory peritoneal dialysis (CAPD), which is mainly observed in patients on long-term therapy. Although some asymptomatic patients must have microscopic calcification in their peritoneum, little information on this topic has been published. Recent studies have revealed active participation of adhesive/chemotactic protein osteopontin (OPN) in dystrophic calcification.