Skin autofluorescence: an emerging biomarker in persons with kidney disease

Purpose of review: Skin autofluorescence (SAF) is a measure of the accumulation of advanced glycation end-products (AGEs) proposed to act as a marker of “cumulative metabolic stress”. This paper discusses mechanisms of AGE formation and reviews published literature on SAF as a biomarker and risk factor across the spectrum of kidney disease. Recent findings: SAF is elevated in adults and children on dialysis. Higher SAF is an independent risk factor for cardiovascular and all-cause mortality in persons receiving haemodialysis and for all-cause mortality in persons performing peritoneal dialysis, though the increase in discrimination when SAF was added to traditional risk factors was modest. In less advanced chronic kidney disease, higher SAF predicts all-cause mortality and progression. SAF is elevated in renal transplant recipients, but to a lesser extent than in dialysis patients. In one study higher SAF predicted graft loss and mortality. SAF has been reported to be increased in patients with acute kidney injury. Summary: A growing body of evidence attests that SAF, a marker of AGE accumulation, is a risk factor for mortality and kidney function decline in multiple types of kidney disease. Further studies are warranted to evaluate interventions to reduce SAF and the impact on clinical outcomes

Real-time expert-system identification of blood pressure measurement accuracy during renal dialysis treatment

Objective: Current practice relies on intermittent occluding arm cuff measurements to monitor blood pressure during hemodialysis and to detect hypotension. However, systematic reviews report measurement accuracy challenges associated with brachial cuff measurements observed in the general population, and the factors contributing to inaccuracy are likely to be accentuated during dialysis treatment. There is currently no formal process to identify unreliable cuff BP measurements, and staff generally rely on ad hoc extra measurements and averaging readings. The objective of the activity described in this paper was to design a computational method to identify unreliable cuff measurements as they are taken and thus provide decision support to practitioners on dialysis units. Reliable intermittent systolic measurements are fundamentally important to both the calibration of continuous blood pressure measurements, and methodologies to predict the onset of hypotension. Methods: Patient studies with concurrent measurements of real-time continuous dialysis line pressure and intermittent systolic brachial cuff pressure during typically 4-hour, dialysis treatment sessions, revealed that some cuff measurements lay outside the prediction bounds associated with the expected quasi-linear (time-varying) relationship between arterial line and brachial pressure measurements. An AI expert system was designed, which embodies the mathematical relationships predicted by a system model, and a further complex rule-set which is able to discriminate between reliable and unreliable cuff measurements in real time based on sparse intermittent incoming data. The developed system was deployed on an observational patient study during hemodialysis treatments, outputting recommendations and justifications for accepting/rejecting cuff measurements. The accepted measurements were fed into a continuous, non-invasive systolic pressure estimator as calibration, enabling the reliability of the decisions made in the arterial line / systolic pressure domain to be verified in the systolic pressure / time domain. Results: Data collected from a prospective, observational patient study exhibited robust identification of unreliable arm cuff measurements, with the system operating as decision support. Continuous, non invasive, SBP predictions exhibited enhanced accuracy, in a typical example case, reducing mean error from 16.7mmHg to 6.8mmHg Conclusion: A hybrid hardware/software system has been designed which utilises non-invasive continuous measurement of arterial dialysis line pressure to improve intermittent arm cuff measurements in order by identifying unreliable arm cuff measurements. The expert system computational core showed robust operation in accepting or excluding incoming arm cuff measurements. The devised system can support two requirements in future applications. Firstly, offering a repeatable and robust methodology to identify unreliable arm cuff measurements. Secondly to support the development of reliable SBP prediction algorithms to enable early intervention to predict hypotensive episodes and enable early intervention to prevent intradialytic hypotension. Abbreviations: cardiovascular disease (CVD); end-stage kidney disease (EKD); intradialytic hypotension (IDH); blood pressure (BP), systolic blood pressure (SBP), diastolic blood pressure (DBP), Hemodialysis (HD), expert system (ES

A feasibility study of non-invasive continuous estimation of brachial pressure derived from arterial and venous lines during dialysis

Intradialytic haemodynamic instability is a significant clinical problem, leading to end-organ ischaemia and contributing to morbidity and mortality in haemodialysis patients. Non-invasive continuous blood pressure monitoring is not part of routine practice but may aid detection and prevention of significant falls in blood pressure during dialysis. Brachial blood pressure is currently recorded intermittently during haemodialysis via a sphygmomanometer. Current methods of continuous non-invasive blood pressure monitoring tend to restrict movement, can be sensitive to external disturbances and patient movement, and can be uncomfortable for the wearer. Additionally, poor patient blood circulation can lead to unreliable measurements. In this study we performed an initial validation of a novel method and associated technology via a feasibility study to continuously estimate blood pressure using pressure sensors in the extra-corporeal dialysis circuit, which does not require any direct contact with the person receiving dialysis treatment.\\ The paper describes the development of the measurement system and subsequent \emph{in vivo} patient feasibility study with concurrent measurement validation by \emph{Finapres Nova} experimental physiological measurement device. We identify a mathematical function to describe the relationship between arterial line pressure and brachial artery BP, which is confirmed in the patient study. The methodology presented requires no interfacing to proprietery dialysis machine systems, no sensors to be attached to the patient directly, and to be robust to patient movement during treatment and also to the effects of the cyclical pressure waveforms induced by the hemodialysis pump. This represents a key enabling factor to the development of a practical continuous blood pressure monitoring device for dialysis patients.This is an output from the iTrend Intelligent Technologies for Renal Dialysis Programme funded by the MStart Charity and iTrend Ltd

The intriguing life of cD galaxies

Objective To assess the available data on the prevalence of metabolic syndrome (MS) in Latin-American countries.Design Systematic review. Searches were carried out in PubMed, ISIWeb, SCielo and Redalyc, using ?metabolic syndrome x' and ?prevalence' as keywords for titles and/or abstracts. Articles selected were cross-sectional studies in Latin-American countries, whose main objective was to study MS and whose study population is described below. MS must be determined using Adult Treatment Panel III criteria. Twelve studies with these criteria were selected, one of which was multi-centric.Setting Latin America.Subjects Apparently healthy subjects aged 18-65 years (including young adult, mature adult and elderly populations) of both genders.Results The general prevalence (weighted mean) of MS in Latin-American countries was 24.9 (range: 18.8-43.3) %. MS was slightly more frequent in women (25.3 %) than in men (23.2 %), and the age group with the highest prevalence of MS consisted of those over 50 years of age. The most frequent components of MS were low HDL cholesterol levels (62.9 %) and abdominal obesity (45.8 %). Similar outcomes were obtained from the multi-centre study on Latin-American populations analysed.Conclusions The present review brings us closer to an understanding of the prevalence of MS in Latin-American countries. However, it is not possible to know the full scope of the problem, partly because data from some countries are not available, and because the methodological differences among the studies published up to the present limit a joint analysis of their results. Copyright " The Authors 2011.",,,,,,"10.1017/S1368980010003320",,,"http://hdl.handle.net/20.500.12104/45242","http://www.scopus.com/inward/record.url?eid=2-s2.0-84855406393&partnerID=40&md5=0ba40f3143e3440abbb2fc20cdc7a05

Effects of a Symbiotic on Gut Microbiota in Mexican Patients With End-Stage Renal Disease

Objectives: Gut microbiota provides beneficial effects under physiological conditions, but is able to contribute to inflammatory diseases in susceptible individuals. Thus, we designed this study to test whether additional intake of symbiotic gel affects specific modifications of gut microbiota in patients with end-stage renal disease (ESRD). Methods: Eighteen patients with ESRD diagnosis with renal replacement therapy (hemodialysis) were included in this study. They were randomly assigned to 2 treatment groups: (1) test group (nutritional counseling\ua0+\ua0symbiotic) and (2) control group (nutritional counseling\ua0+\ua0placebo). Clinical history and the evaluation of Gastrointestinal Symptom Rating Scale were performed. Gut microbiota composition was analyzed by real-time polymerase chain reaction from fecal samples. All subjects were followed for 2\ua0months. Results: Bifidobacterial counts were higher in the second samples (mean: 5.5\ua0±\ua01.72 log10 cells/g) than in first samples (4.2\ua0±\ua00.88 log 10\ua0cells/g) in the patients of the test group (P\ua0=\ua0.0344). Also, lactobacilli counts had a little decrease in the test group (2.3\ua0±\ua00.75 to 2.0\ua0±\ua00.88 log 10 cells/g) and the control group (2.2\ua0±\ua00.90 to 1.8\ua0±\ua01.33 log 10 cells/g), between the first and the second samples. Gastrointestinal symptoms scores (scale 8-40) were reduced in the test group (start 12 [10-14] and end 9 [8-10]) compared with control group (start 11 [8-21] and end 11 [9-15]). Conclusions: Short-term symbiotic treatment in patients with ESRD can lead to the increase of Bifidobacterium counts, maintaining the intestinal microbial balance. © 2014 National Kidney Foundation, Inc

EELS analysis of Nylon 6 nanofibers reinforced with nitroxide- functionalized graphene oxide

Objective: The study aimed to assess the effect of a symbiotic gel on presence and severity of gastrointestinal symptoms (GIS) in hemodialysis patients. Design: A double-blinded, placebo-controlled, randomized, clinical trial was designed. The study was conducted at 2 public hospitals in Guadalajara, Mexico. Subjects and Intervention: Twenty-two patients were randomized to the intervention group (nutritional counseling+symbiotic gel) and 20 patients were randomized to the control group (nutritional counseling+placebo), during 2months of follow-up. Main Outcome Measure: Presence and monthly episodes of GIS were assessed by direct interview and severity by using the self-administered GIS questionnaire. Additionally, biochemical parameters, inflammatory markers, and nutritional status (dietary intake, subjective global assessment, anthropometry, and body composition) were evaluated. Results: After a 2-month treatment, intervention group had a significant reduction in prevalence and monthly episodes of vomit, heartburn, and stomachache, as well as a significant decrease in GIS severity compared with control group. Moreover, intervention group had a greater yet not significant decrease in the prevalence of malnutrition and a trend to reduce their C-reactive protein and tumor necrosis factor ? levels compared with control group. No symbiotic-related adverse side effects were shown in these patients. Clinical studies with longer follow-up and sample size are needed to confirm these results. Conclusions: We concluded that administration of a symbiotic gel is a safe and simple way to improve common GIS in dialysis patients. " 2015 National Kidney Foundation, Inc.",,,,,,"10.1053/j.jrn.2014.09.008",,,"http://hdl.handle.net/20.500.12104/40898","http://www.scopus.com/inward/record.url?eid=2-s2.0-84928161969&partnerID=40&md5=e3ae60e49222f72f6aae48d8bc226dd