Thermal conductivity vs depth profiling using the hot disk technique-Analysis of anisotropic, inhomogeneous structures.

A recently developed method for analyzing the thermal conductivity vs depth variation near a sample surface has been extended to include inhomogeneous samples with anisotropy. If not considered, the anisotropy ratio in the sample structure can distort the depth-position data of the original test method. The anisotropy ratio is introduced in the original computational scheme in order to improve the depth-position estimations for inhomogeneous structures with anisotropy. The proposed approach has been tested in experiments and shown to improve depth position mapping.

Evaluating reflective practice groups in a mental health context: Swedish translation and psychometric evaluation of the clinical supervision evaluation questionnaire.

BACKGROUND: Implementation of reflective practice groups in psychiatric and mental health contexts might improve the quality of care through promoting self-awareness, clinical insight, and facilitating stress management and team building. There is a need for valid and reliable instruments to test the outcomes of reflective practice groups in the mental health context. This study aimed to test the validity and reliability of the Swedish version of the Clinical Supervision Evaluation Questionnaire. METHODS: The instrument was translated from English to Swedish using a translation and back-translation procedure. Data for the calculation of content validity was collected from an expert group. Data for the reliability analysis was collected from rehabilitation assistants and ward managers participating in reflective practice groups (n = 20). Content validity was measured by computing a content validity index. Construct validity was assessed by calculating the corrected item-total correlation statistics. Reliability was evaluated by analysing the Cronbach's alpha coefficient, the intraclass correlation coefficient and inter-item correlations. RESULTS: The content validity index for the scale as a whole was 0.94. Item-total correlations ranged between 0.23 and 0.81, and deletion of an item did not notably improve Cronbach's alpha. Cronbach's alpha for the scale was 0.89. The intraclass correlation coefficient for single measures was 0.35. The mean inter-item correlation was .37. CONCLUSION: The Swedish version of the Supervision Evaluation Questionnaire has a degree of reliability and validity that is comparable to the original version in English, indicating that it can be used as an assessment of reflective practice groups in the mental health context.

A DNA methylation biomarker of alcohol consumption.

The lack of reliable measures of alcohol intake is a major obstacle to the diagnosis and treatment of alcohol-related diseases. Epigenetic modifications such as DNA methylation may provide novel biomarkers of alcohol use. To examine this possibility, we performed an epigenome-wide association study of methylation of cytosine-phosphate-guanine dinucleotide (CpG) sites in relation to alcohol intake in 13 population-based cohorts (ntotal=13 317; 54% women; mean age across cohorts 42-76 years) using whole blood (9643 European and 2423 African ancestries) or monocyte-derived DNA (588 European, 263 African and 400 Hispanic ancestry) samples. We performed meta-analysis and variable selection in whole-blood samples of people of European ancestry (n=6926) and identified 144 CpGs that provided substantial discrimination (area under the curve=0.90-0.99) for current heavy alcohol intake (⩾42 g per day in men and ⩾28 g per day in women) in four replication cohorts. The ancestry-stratified meta-analysis in whole blood identified 328 (9643 European ancestry samples) and 165 (2423 African ancestry samples) alcohol-related CpGs at Bonferroni-adjusted P<1 × 10-7. Analysis of the monocyte-derived DNA (n=1251) identified 62 alcohol-related CpGs at P<1 × 10-7. In whole-blood samples of people of European ancestry, we detected differential methylation in two neurotransmitter receptor genes, the γ-Aminobutyric acid-A receptor delta and γ-aminobutyric acid B receptor subunit 1; their differential methylation was associated with expression levels of a number of genes involved in immune function. In conclusion, we have identified a robust alcohol-related DNA methylation signature and shown the potential utility of DNA methylation as a clinically useful diagnostic test to detect current heavy alcohol consumption.

Targeted proteomic analysis of habitual coffee consumption.

BACKGROUND: Coffee drinking has been implicated in mortality and a variety of diseases but potential mechanisms underlying these associations are unclear. Large-scale systems epidemiological approaches may offer novel insights to mechanisms underlying associations of coffee with health. OBJECTIVE: We performed an analysis of known and novel protein markers linked to cardiovascular disease and their association with habitual coffee intake in the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS, n = 816) and followed up top proteins in the Uppsala Longitudinal Study of Adult Men (ULSAM, n = 635) and EpiHealth (n = 2418). METHODS: In PIVUS and ULSAM, coffee intake was measured by 7-day dietary records whilst a computer-based food frequency questionnaire was used in EpiHealth. Levels of up to 80 proteins were assessed in plasma by a proximity extension assay. RESULTS: Four protein-coffee associations adjusted for age, sex, smoking and BMI, met statistical significance in PIVUS (FDR < 5%, P < 2.31 × 10-3 ): leptin (LEP), chitinase-3-like protein 1 (CHI3L), tumour necrosis factor (TNF) receptor 6 and TNF-related apoptosis-inducing ligand. The inverse association between coffee intake and LEP replicated in ULSAM (ß, -0.042 SD per cup of coffee, P = 0.028) and EpiHealth (ß, -0.025 SD per time of coffee, P = 0.004). The negative coffee-CHI3L association replicated in EpiHealth (ß, -0.07, P = 1.15 × 10-7 ), but not in ULSAM (ß, -0.034, P = 0.16). CONCLUSIONS: The current study supports an inverse association between coffee intake and plasma LEP and CHI3L1 levels. The coffee-CHI3L1 association is novel and warrants further investigation given links between CHI3L1 and health conditions that are also potentially influenced by coffee.

Interconnectivity imaged in three dimensions: Nano-particulate silica-hydrogel structure revealed using electron tomography.

We have used Electron Tomography (ET) to reveal the detailed three-dimensional structure of particulate hydrogels, a material category common in e.g. controlled release, food science, battery and biomedical applications. A full understanding of the transport properties of these gels requires knowledge about the pore structure and in particular the interconnectivity in three dimensions, since the transport takes the path of lowest resistance. The image series for ET were recorded using High-Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM). We have studied three different particulate silica hydrogels based on primary particles with sizes ranging from 3.6nm to 22nm and with pore-size averages from 18nm to 310nm. Here, we highlight the nanostructure of the particle network and the interpenetrating pore network in two and three dimensions. The interconnectivity and distribution of width of the porous channels were obtained from the three-dimensional tomography studies while they cannot unambiguously be obtained from the two-dimensional data. Using ET, we compared the interconnectivity and accessible pore volume fraction as a function of pore size, based on direct images on the nanoscale of three different hydrogels. From this comparison, it was clear that the finest of the gels differentiated from the other two. Despite the almost identical flow properties of the two finer gels, they showed large differences concerning the accessible pore volume fraction for probes corresponding to their (two-dimensional) mean pore size. Using 2D pore size data, the finest gel provided an accessible pore volume fraction of over 90%, but for the other two gels the equivalent was only 10-20%. However, all the gels provided an accessible pore volume fraction of 30-40% when taking the third dimension into account.

Case management at an outpatient unit for severe and enduring eating disorder patients at Stockholm Centre for Eating Disorders- a study protocol.

BACKGROUND: Patients with severe and enduring eating disorders (SEED) are seriously ill and have a low quality of life. Case management (CM), originally developed for adult patients with severe mental disabilities, has been shown to enhance social functioning and improve quality of life, while reducing the number and length of hospitalizations. In 2014, a special unit based on CM, for patients with SEED (the Eira unit) was started at Stockholm Centre for Eating Disorders, Sweden. METHOD/DESIGN: This study aims to investigate if CM can improve SEED patients' quality of life, and reduce their eating disorder symptoms as well as their health care consumption. Methods for data collection are a semi-structured diagnostic interview, self-report questionnaires, and a qualitative interview. The diagnostic interview and the self-report assessments will be done at start of treatment and at follow-ups after 1, 2, and 3years. The qualitative interview will be conducted 1 year after start of treatment. The study is approved by the ethical review board in Stockholm in compliance with the Helsinki Declaration. DISCUSSION: CM is a possible new contribution to the treatment methods for SEED. It does not aim at remission, but rather to accept life as it is, and to enhance quality of life in the presence of the ED. This study will investigate the potential benefits of this novel intervention in a special unit for SEED patients. TRIAL REGISTRATION: Clinicaltrials.gov Id: NCT02897622.

Thermal conductivity versus depth profiling of inhomogeneous materials using the hot disc technique.

Transient measurements of thermal conductivity are performed with hot disc sensors on samples having a thermal conductivity variation adjacent to the sample surface. A modified computational approach is introduced, which provides a method of connecting the time-variable to a corresponding depth-position. This allows highly approximate-yet reproducible-estimations of the thermal conductivity vs. depth. Tests are made on samples incorporating different degrees of sharp structural defects at a certain depth position inside a sample. The proposed methodology opens up new possibilities to perform non-destructive testing; for instance, verifying thermal conductivity homogeneity in a sample, or estimating the thickness of a deviating zone near the sample surface (such as a skin tumor), or testing for presence of other defects.

Pulse transient hot strip technique adapted for slab sample geometry to study anisotropic thermal transport properties of µm-thin crystalline films.

A new method based on the adaptation of the Pulse Transient Hot Strip technique to slab sample geometry has been developed for studying thermal conductivity and thermal diffusivity of anisotropic thin film materials (<50 µm) with thermal conductivity in the 0.01-100 W/mK range, deposited on thin substrates (i.e., wafers). Strength of this technique is that it provides a well-controlled thermal probing depth, making it possible to probe a predetermined depth of the sample layer and thereby avoiding the influence from material(s) deeper down in the sample. To verify the technique a series of measurements were conducted on a y-cut single crystal quartz wafer. A Hot Strip sensor (32-µm wide, 3.2-mm long) was deposited along two orthogonal crystallographic (x- and z-) directions and two independent pulse transients were recorded. Thereafter, the data was fitted to our theoretical model, and the anisotropic thermal transport properties were determined. Using a thermal probing depth of only 30 µm, we obtained a thermal conductivity along the perpendicular (parallel) direction to the z-, i.e., optic axis of 6.48 (11.4) W/mK, and a thermal diffusivity of 3.62 (6.52) mm(2)/s. This yields a volumetric specific heat of 1.79 MJ/mK. These values agree well with tabulated data on bulk crystalline quartz supporting the accuracy of the technique, and the obtained standard deviation of less than 2.7% demonstrates the precision of this new measurement technique.

Perceptions of participating in high-intensity functional exercise among older people dependent in activities of daily living (ADL).

The purpose of the study was to evaluate how older people, dependent in ADL perceive their participation in a high-intensity, functional exercise program compared to the perceptions of those participating in a control activity. Forty-eight older people living in residential care facilities answered a questionnaire about their perceptions of participating in an activity for three months. They were aged 65-98, had a mean score of 24 on Mini Mental State Examination (MMSE) and 14 on Barthel ADL Index. The participants had been randomized to exercise (n=20) or control activity (n=28). Differences in responses between exercise and control activity were evaluated using logistic and ordinal regression analyses. The results show that a majority of the exercise group perceived positive changes in lower limb strength, balance, and in the ability to move more safely and securely compared to a minority of the control group (p<0.001). Significantly more respondents in the exercise activity answered that they felt less tired due to the activity (p=0.027) and that they prioritized this activity above other activities (p=0.010). More exercise participants reported that meeting for three months was too short, and fewer that it was too long compared to the control group (p=0.038). This study shows that older people living in residential care facilities, dependent in ADL, and with mild or no cognitive impairment had positive perceptions about participating in high-intensity functional exercise. The findings support the use of a high-intensity exercise program in this population of older people.

Sunlight is associated with decreased multiple sclerosis risk: no interaction with human leukocyte antigen-DRB1*15.

BACKGROUND: Both insufficient exposure to sunlight and vitamin D deficiency have been associated with an increased risk for multiple sclerosis (MS). An interaction between human leukocyte antigen HLA-DRB1*15 and vitamin D in MS was recently proposed. We investigated the association between previous exposure to ultraviolet radiation (UVR), vitamin D status at inclusion in the study, and MS risk including the interaction of these factors with HLA-DRB1*15. METHODS: A population-based case-control study involving 1013 incident cases of MS and 1194 controls was performed in Sweden during 2005-2010. Subjects were classified according to their UVR exposure habits, vitamin D status, and HLA genotypes. The associations between different sun exposure habits/vitamin D levels and MS were calculated as odds ratios (OR) with 95% confidence intervals (CI) using logistic regression. Potential interaction was evaluated by calculating the attributable proportion due to interaction. RESULTS: Subjects with low UVR exposure had a significantly increased risk of MS compared with those who reported the highest exposure (OR 2.2, 95% CI 1.5-3.3). Similarly, subjects who had 25-hydroxy-vitamin D levels less than 50 nM/l had an increased risk for MS (OR 1.4, 95% CI 1.2-1.7). The association between UVR exposure and MS risk persisted after adjustment for vitamin D status. There was no interaction with HLA-DRB1*15 carriage. CONCLUSIONS: UVR and vitamin D seem to affect MS risk in adults independently of HLA-DRB1*15 status. UVR exposure may also exert a protective effect against developing MS via other pathways than those involving vitamin D.

An in vivo comparison of hip structure analysis (HSA) with measurements obtained by QCT.

SUMMARY: In a population of elderly women, bone cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (Z), femoral neck axis length (FNAL), and width measured with hip structure analysis (HSA) on dual-energy x-ray absorptiometry (DXA) images in the femoral neck and trochanteric regions are highly correlated to quantitative computed tomography (QCT) measurements. INTRODUCTION: HSA is a method of obtaining measurements of proximal femur structure using 2D DXA technology. This study was designed to examine the correlations between HSA measurements and 3D QCT. METHODS: Forty-one women (mean age, 82.8 ± 2.5 years) were measured using DXA and a 64-slice CT scanner (1 mm slice thickness, 0.29 mm in plane resolution). HSA parameters were calculated at the narrow neck (NN) and trochanteric (IT) regions on the DXA image. These regions were then translated to anatomically equivalent regions on the QCT dataset by co-registering the DXA image and QCT dataset using four DXA images acquired at different angles. RESULTS: At the NN and IT regions, high linear correlations were measured between HSA and QCT for CSA r = 0.95 and 0.93, CSMI r = 0.94 and 0.93, and Z r = 0.93 and 0.89, respectively. All correlations were highly significant (p < 0.001), but there were differences in slope and offset between the two techniques, at least in part due to differences in calibration between the two techniques. FNAL and width of the bone at the NN and IT regions, physical measurements independent of the calibration, were highly correlated (r = 0.90-0.95, p < 0.001) and had slopes close to 1.0 (range, 0.978 to 1.003). CONCLUSION: CSA, CSMI, Z, FNAL, and width measured by HSA correlate highly to high-resolution QCT.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2009-30 November 2009.

This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus oryzae, Aspergillus terreus, Branchiostoma japonicum, Branchiostoma belcheri, Colias behrii, Coryphopterus personatus, Cynogolssus semilaevis, Cynoglossus semilaevis, Dendrobium officinale, Dendrobium officinale, Dysoxylum malabaricum, Metrioptera roeselii, Myrmeciza exsul, Ochotona thibetana, Neosartorya fischeri, Nothofagus pumilio, Onychodactylus fischeri, Phoenicopterus roseus, Salvia officinalis L., Scylla paramamosain, Silene latifo, Sula sula, and Vulpes vulpes. These loci were cross-tested on the following species: Aspergillus giganteus, Colias pelidne, Colias interior, Colias meadii, Colias eurytheme, Coryphopterus lipernes, Coryphopterus glaucofrenum, Coryphopterus eidolon, Gnatholepis thompsoni, Elacatinus evelynae, Dendrobium loddigesii Dendrobium devonianum, Dysoxylum binectariferum, Nothofagus antarctica, Nothofagus dombeyii, Nothofagus nervosa, Nothofagus obliqua, Sula nebouxii, and Sula variegata. This article also documents the addition of 39 sequencing primer pairs and 15 allele specific primers or probes for Paralithodes camtschaticus.

Defocus convergent beam electron diffraction analysis of dislocations in mullite.

Burgers vectors of matrix dislocations in mullite have been determined by the defocus large-angle convergent beam electron diffraction technique. Vectors of the types [100], [010], [110] and [112] were identified. These Burgers vectors are discussed in relation to the open channels and the oxygen vacancy distribution in the mullite structure. It is suggested that a short-range ordering of oxygen vacancies may account for a Burgers vector of the type [112].

Comparison of QCT-derived and DXA-derived areal bone mineral density and T scores.

UNLABELLED: Two-dimensional areal bone mineral density (aBMD) of the proximal femur measured by three-dimensional quantitative computed tomography (QCT) in 91 elderly women was compared to dual-energy X-ray absorptiometry (DXA) aBMD results measured in the same patients. The measurements were highly correlated, though QCT aBMD values were marginally lower in absolute units. Transformation of the QCT aBMD values to T score values using National Health and Nutrition Examination Survey (NHANES) DXA-derived reference data improved agreement and clinical utility. INTRODUCTION: World Health Organization guidelines promulgate aBMD (g cm(-2)) measurement of the proximal femur for the diagnosis of bone fragility. In recent years, there has been increasing interest in QCT to facilitate understanding of three-dimensional bone structure and strength. OBJECTIVE: To assist in comparison of QCT-derived data with DXA aBMD results, a technique for deriving aBMD from QCT measurements has been developed. METHODS: To test the validity of the QCT method, 91 elderly females were scanned on both DXA and CT scanners. QCT-derived DXA equivalent aBMD (QCT(DXA) aBMD) was calculated using CTXA Hip software (Mindways Software Inc., Austin, TX, USA) and compared to DXA-derived aBMD results. RESULTS: Test retest analysis indicated lower root mean square (RMS) errors for CTXA; F test between CTXA and DXA was significantly different at femoral neck (FN) and trochanter (TR) (p < 0.05). QCT underestimates DXA values by 0.02 +/- 0.05 g cm(-2) (total hip, TH), 0.01 +/- 0.04 g cm(-2) (FN), 0.03 +/- 0.07 g cm(-2) (inter-trochanter, IT), and 0.02 +/- 0.05 g cm(-2) (TR). The RMS errors (standard error of estimate) between QCT and DXA T scores for TH, FN, IT, and TR were 0.36, 0.40, 0.39, and 0.49, respectively. CONCLUSIONS: This study shows that results from QCT aBMD appropriately adjusted can be evaluated against NHANES reference data to diagnose osteoporosis.

Lack of insulin-like growth factor binding protein-3 protease activation by venous cannulation.

Disruption of the endothelium activates thrombogenic and fibrinolytic enzymes that cleave insulin-like growth factor binding protein-3 (IGFBP-3) in vitro. The aim of the present human study was to determine whether blood sampling, i.e., venous stasis and cannulation increase IGFBP-3 proteolysis before and/or after surgery by activating these enzymes. Serum samples obtained immediately after cannulation were compared with samples obtained from a previously inserted venous catheter. Cannulation did not increase serum IGFBP-3 proteolytic activity pre- and post-operatively, as determined by in vitro degradation of 125I-IGFBP-3. Furthermore, there was no effect on in vivo IGFBP-3 fragmentation assessed by western immunoblot. In addition, a standardized venous stasis did not affect IGFBP-3 proteolytic activity or fragmentation. Comparison of IGFBP-3 proteolytic activity before and after surgery demonstrated a significant post-operative increase. However, this could not be demonstrated immediately after the initial cannulation, due to a large individual variation at this time-point before surgery.

Serum cardiac troponin T in patients hospitalized with heart failure is associated with left ventricular hypertrophy and systolic dysfunction.

BACKGROUND: Cardiac troponin T (cTnT) is a highly sensitive and specific marker of acute myocardial infarction. Serum cTnT is also slightly elevated in patients with severe heart failure and is associated with left ventricular hypertrophy (LVH) in patients treated with haemodialysis. In this study serum cTnT concentrations and echocardiographic findings were investigated in heart failure patients without acute coronary syndrome. cTnT was also compared with other cardiac markers and plasma levels of brain natriuretic peptide (BNP). METHODS: Twenty-six patients hospitalized with heart failure were included in the study. Echocardiographic measurements and blood sampling were carried out 12-36 h after admission. Serum cTnT (3rd generation assay), cardiac troponin I (cTnI), creatine kinase MB (CKMB) and CK were measured. Plasma BNP was analysed using the Shionoria assay. LVH was defined as left ventricular mass index (LVMI) > 125 g/m for males and > 110 g/m for females. Left ventricular systolic function was estimated from the mitral annulus motion (AV-mean LV). RESULTS: Median cTnT was 0.012 (< 0.010-0.032) microg/L. Sixty-two percent of the patients (16 of 26) had elevated serum cTnT >or= 0.010 micro/L. cTnT was positively correlated with CKMB (rho = 0.40, p = 0.04) and BNP (rho = 0.43, p = 0.03), but not with cTnI and CK. A negative correlation was found between cTnT and AV-mean LV (rho = -0.58, p = 0.007), and there was a positive correlation between cTnT and LVMI (rho = 0.44, p = 0.03). No other analyte was correlated to LVMI. CONCLUSIONS: Serum cTnT but not cTnI was associated with left ventricular dysfunction and LVH in patients hospitalized with heart failure. This explains why cTnT tends to be slightly elevated in patients with heart failure without symptoms of acute myocardial ischaemia.

A new mathematical model for chemotactic bacterial colony growth.

A new continuum model for the growth of a single species biofilm is proposed. The geometry of the biofilm is described by the interface between the biomass and the surrounding liquid. Nutrient transport is given by the solution of a semi-linear Poisson equation. In this model we study the morphology of a chemotactic bacterial colony, which grows in the direction of increasing nutrient concentration. Numerical simulations using the level set method and finite difference schemes are presented. The results show rich heterogeneous morphology.

Genetic differentiation and habitat preference of flowering-time variants within Gymnadenia conopsea.

Using fast-evolving microsatellites, more slowly evolving ITS markers and performing habitat analyses, we demonstrated a drastic genetic divergence and significant habitat differentiation between early- and late-flowering variants of plants morphologically belonging to Gymnadenia conopsea ssp conopsea. The two phenological variants can either be found in separate or in mixed populations. Information from microsatellite markers and ITS sequences indicated the occurrence of an early historical split between the two flowering-time variants, a split that has been maintained until the present time even within sympatric populations. Early-flowering variants were also far more genetically diverse, had more alleles per microsatellite locus and a wider habitat amplitude than late-flowering variants. As a comparison, we included G. odoratissima in the sequencing study. We found G. odoratissima to be most closely related to the early-flowering type. This indicates a more ancient divergence event between the two flowering-time variants within G. conopsea ssp conopsea than between the two different species G. odoratissima and the early-flowering variant of G. conopsea. Possible explanations to the results arrived at and possible mechanisms maintaining the genetic separation are discussed.

Elevated cardiac troponin T in predialysis patients is associated with inflammation and predicts mortality.

OBJECTIVES: Cardiac troponin T (cTnT) is a highly sensitive and specific marker of myocardial damage. It has been shown that elevated serum concentrations of cTnT in haemodialysis (HD) patients are associated with poor prognostic outcome. The aim of the present study was to investigate the predictive value of cTnT in samples from predialysis patients and to investigate associations between cTnT and inflammatory markers, such as C-reactive protein (CRP) and interleukin-6 (IL-6). DESIGN: Cohort, follow-up study. SETTING: Huddinge University Hospital, Sweden. SUBJECTS: A total of 115 (62% males, 28% diabetic patients) end-stage renal disease (ESRD) patients (52 +/- 1 years), of which 29% had cardiovascular disease (CVD), were studied shortly before the onset of dialysis therapy. Sixty-four patients started peritoneal dialysis (PD) as renal replacement therapy, whilst 49 started HD during the follow-up. MAIN OUTCOME MEASURES: The cTnT was analysed with the third generation TnT assay on Elecsys 2010. The prognostic value was calculated for cTnT, IL-6, age, CVD, malnutrition, diabetes mellitus (DM) and gender. Survival analyses were made with Kaplan-Meier and Cox regression analyses, with all-cause mortality as the clinical end point (mean follow-up period 2.7 +/- 0.1 years). RESULTS: Significant correlations were found between cTnT and CKMB (rho = 0.52, P < 0.0001), IL-6 (rho = 0.23, P < 0.05), CRP (rho = 0.30, P < 0.05), and serum albumin (rho = -0.31, P < 0.001), respectively. Diabetic patients had higher median serum cTnT level (0.09 microg L-1; range <0.01-0.51 vs. 0.04 microg L-1; range <0.01-0.67 microg L-1; P < 0.005) compared with nondiabetic patients. Likewise, patients with CVD had a significantly higher median level (0.08 microg L-1; range <0.01-0.67 microg L-1 vs. 0.04 microg L-1; range <0.01-0.61 microg L-1; P < 0.01) of cTnT compared with patients without CVD. Patients with cTnT > or =0.10 microg L-1 had a higher cumulative mortality rate than patients with cTnT < 0.10 microg L-1 (chi2 = 7.04; P < 0.01). Whilst age, CVD, malnutrition, DM, IL-6, cTnT and male gender were associated with poor outcome in the univariate analysis, only DM (P < 0.05) and cTnT (P < 0.05) were independently associated with mortality in a multivariate analysis. CONCLUSIONS: The present study demonstrates that serum concentrations of cTnT > or =0.10 microg L-1 is a significant predictor of mortality in patients starting dialysis. Moreover, the positive correlations between cTnT and IL-6, and CRP, respectively, suggest an association between inflammation and cTnT levels. Finally, the results of the present study suggest that cTnT is an independent predictor of mortality in ESRD patients starting dialysis.

Importance of preanalytical handling of samples for measurement of cardiac troponin T in coronary effluent from isolated rat hearts.

The isolated, buffer-perfused heart is probably the most widely used model in experimental heart research, and the coronary effluent is often analysed for markers of myocardial injury. Adsorption to surrounding materials may be a serious problem of protein measurements in solutions with low protein concentrations. The aims of the present study were to investigate the importance of the preanalytical phase when measuring cardiac troponin T (cTnT) in a buffer perfusate and to investigate whether addition of albumin to the effluent might increase recovery of cTnT and improve the assay. Coronary effluent was collected in tubes of different materials and in tubes with 40 g/L bovine albumin, and then frozen. cTnT was analysed at different time points after withdrawal from the freezer. cTnT was 2.3-119 times higher in effluent with albumin. In effluent without albumin, cTnT concentration declined to 2% of the initial concentration after two episodes of freezing and thawing. The cTnT loss could not be prevented by using polystyrene or siliconized glass, but was partially inhibited in effluent with albumin. Furthermore, creatine kinase and lactate dehydrogenase levels were higher in effluent with albumin. The within-series coefficient of variation for cTnT was markedly improved when using effluent with albumin.