2D) Importantly, all vaccinated mice rapidly lost weight and suc

2D). Importantly, all vaccinated mice rapidly lost weight and succumbed to LCMV infection while nonvaccinated mice exhibited less weight loss and survived (Fig. 2E and F). In order to further decrease the number of memory CD8+ T cells we performed adoptive transfer of different numbers of NP118-specific memory CD8+ T cells (ranging from 8 × 102 cells to 8 × 105 cells per mouse) into naïve PKO hosts. The NP118-specific population of memory CD8+ T cells transferred exhibited a late memory phenotype (CD127hi, LDE225 order CD62Lhi, KLRG-1lo, CD27hi) and function (IL-2 and TNF cytokine production upon restimulation with NP118 peptide; Fig. 3A). All recipient

mice and a group that did not receive memory CD8+ T cells were challenged with LCMV-Arm. Mice receiving 8 × 105 and 8 × 104 NP118-specific memory CD8+ T cells rapidly lost weight and succumbed following LCMV infection (Fig. 3B and C). Interestingly, mice receiving 8 × 103 NP118-specific memory CD8+ T cells lost weight during the first week after LCMV infection but recovered without any mortality. On the other hand, mice receiving 8 × 102 NP118-specific memory CD8+ T cells exhibited only slight weight loss and did not succumb, similar to control mice that did not receive any memory CD8+ T cells (Fig. 3B and C). Consistent with their poor outcome, mice receiving either 8 × 105 or 8 × 104 NP118-specific

memory CD8+ T cells had high numbers (>107 cells/spleen) at 5 days post-LCMV infection (Fig. 3D). Importantly, a substantial fraction of NP118-specific secondary effector CD8+ T cells in the groups receiving the highest numbers AT9283 cell line of memory CD8+ T Protein kinase N1 cells produced IFN-γ

directly ex vivo even in the absence of exogenous peptide stimulation (Fig. 3D). Together, these results suggested that secondary CD8+ T cells expansion and mortality in PKO mice are dictated by the starting number of NP118-specific memory CD8+ T cells at the time of LCMV challenge. Naïve PKO mice survive LCMV-Arm infection by exhausting their NP118-specific CD8+ T cells [[16]]. Furthermore, more than 98% of the CD8+ T cells response to LCMV infection in BALB/c mice is directed at the dominant NP118 epitope, with subdominant responses directed to GP283 and GP96 epitopes [[34, 35]]. Previous work showed that vaccination to generate wild-type memory CD8+ T cells against subdominant epitopes may be effective at protecting from both LCMV and LM infection [[36, 37]]. However, it remains unknown whether memory CD8+ T cells specific for subdominant LCMV epitopes will also lead to vaccine-induced mortality in perforin-deficient hosts. To address this issue, we immunized naïve PKO mice with 5 × 105 DC coated with either the dominant NP118 or subdominant GP283 LCMV epitopes, while mice in the control group received DC coated with a Plasmodium berghei CS252 epitope.

Candida albicans was the predominant yeast isolated [30 patients

Candida albicans was the predominant yeast isolated [30 patients (62.5%)], followed by C. parapsilosis [6 (12.5%)] and C. dubliniensis 5 (10.4%). Aspergillus fumigatus was the most common filamentous fungus [5 (10.4%)] and non-fumigatus Aspergillus species were isolated from four (8.3%) patients. Staphylococcus aureus was the most frequently detected bacterium in C. Hedgehog antagonist albicans

positive samples (53.57%). A. fumigatus and Pseudomonas aeruginosa or S. aureus were detected together in 75% of A. fumigatus positive samples each. No statistically significant relationship was detected between growth of yeast and moulds and age, gender, the use of inhaled corticosteroids or tobramycin. No significant correlation was found between the isolation of C. albicans, A. fumigatus and P. aeruginosa, Stenotrophomonas maltophilia selleck chemicals llc or S. aureus, and the isolation of C. albicans and Haemophilus influenzae. Other factors which may be responsible for the increased isolation of fungi in CF need to be investigated. “
“Patients with acute myelogenous leukaemia (AML) and neutropenia after chemotherapy are at high risk for life-threatening invasive fungal disease (IFD), in particular, invasive aspergillosis (IA). The aim of the study was to evaluate data on characteristics, risk factors, complications and additional

antifungal treatment of patients with AML receiving posaconazole prophylaxis (PP) after chemotherapy in an actual clinical setting. A retrospective single-centre observational study on 40 patients with AML, median age 66 years, was conducted. PP 200 mg three times daily was given routinely. After 76 cycles of remission induction chemotherapy followed by PP, median duration of 31 days (range 6–61 days), no fatal case occurred. second The majority of patients had at least one additional risk factor for IFD and during 32 cycles (42.1%), three risk factors were present. During 40 therapy cycles (52.6%), fever of unknown origin occurred. Pneumonia was diagnosed after 23 cycles

(30.3%), thereof one case of proven IA (1.3%). PP was interrupted in 25 cycles (32.9%) and was followed by systemic antifungal therapy with different agents, with a median duration 15 days (range: 6–32 days). PP appears to be an effective and well-tolerated protection against IFD for AML patients under natural clinical conditions. “
“Data on the epidemiology of invasive Candida infections in paediatric patients in Europe are still limited. The aim of this retrospective study was to analyse the epidemiology of candidaemia in a tertiary paediatric hospital in Poland from 2000 to 2010. Using microbiological records, a total of 118 episodes of candidaemia were identified in 114 children, with an annual incidence of 0.35 episodes/1000 discharges. The highest incidences were found in the medical intensive care unit (5.28), and in neonatal intensive care (1.47). The mortality rate was 8.5%. Candida albicans and C. parapsilosis were the most prevalent species (39.8% and 35.6% respectively).

It was noted that the punctate immunostaining for MSA-1 was accom

It was noted that the punctate immunostaining for MSA-1 was accompanied by sparse CD13 staining and always in juxtaposition to redistributed iDCs. We have previously shown that maturation of splenic iDC from naïve calves in vitro results in the loss of CD13 expression and gain in capacity to present antigen (12,41). Thus, similar to the P. chabaudi model in mice (23), these results

support the hypothesis that iDC mature during processing of the parasite and migrate as antigen-presenting cells to lymphocyte-rich domains. The spleen-dependent innate response of naïve selleck products calves to infection with B. bovis is also characterized by early IL-12 production with subsequent IL-10 modulation (6), the major sources of which in cattle are iDCs and monocytes/macrophages, respectively (8,14,42). We have also shown that monocytes/macrophages of cattle can produce NO with direct babesiacidal activity (14,27,43). It was interesting to note that following haemoparasitic infection, intense acute hyperplasia of monocytes/macrophages is restricted to the red pulp of both mice (23) and calves (present study). Thus, in addition to regulatory function through cytokine production, our collective findings are consistent with monocytes/macrophages acting as effector cells in close juxtaposition with infected erythrocytes as they enter

the splenic sinuses. Regarding the distribution of small leucocytes, dual-labelling experiments demonstrated acute progressive accumulation of numerous CD3+ CD4− cells and TcR1+ WC1− cells within the red Quizartinib pulp. Thus, it is likely that at least a portion of these accumulated Cytidine deaminase lymphocytes were WC1−γδ T cells. The role of these cells is still not clear but as bovine WC1−γδ T cells express CD2 and CD8, can produce

IFN-γ in response to cytokine stimulation, and are found in largest proportion in the spleen and intestine (15,16,44,45), it is intriguing to consider the possibility that cells with this phenotype might be the bovine functional equivalent of NKT cells (46–48). If so, then the observed accumulation of these cells in the red pulp of naïve calves infected with B. bovis is consistent with their expected role in the transition from innate to acquired immunity. Our results are in agreement with previous reports (49,50) that demonstrate relatively small accumulations of WC1+γδ T cells within the splenic marginal zones of uninfected calves. The splenic decrease in WC1+γδ T cells during the acute response of calves to B. bovis infection may indicate their activation within the marginal zone is followed by redistribution to effector sites outside of the spleen. Indeed, several reports indicate WC1+γδ T cells are most numerous and reactive within the blood of young calves (45,49,51–53).

Early in the disease process systemic mRNA expression of T-bet an

Early in the disease process systemic mRNA expression of T-bet and Rorγ was increased in STAT6–/– mice. We conclude that STAT6 is required for attenuation of Th1 and Th17 nephritogenic immune responses and protection from crescentic glomerulonephritis. Glomerulonephritis (GN) is a common cause of renal disease, including end-stage renal failure. Experimental crescentic GN is the murine homologue of rapidly progressive

GN, the most severe form of GN. Severe injury in this model is mediated by cellular immunity and CD4+ T cells are key components of renal injury [1,2]. Upon activation, naive CD4+ cells tend to differentiate into subsets (T helper cells – Th1, Th2 and Th17) that engage immune effectors in different ways. In proliferative forms of Proteasome inhibition GN, T cells direct adaptive immune responses that drive glomerular disease, but also, in rapidly progressive GN, CD4+ cells themselves accumulate in glomeruli as effectors. These effector Selleck BMN-673 T helper cells activate innate immune effector cells, predominantly neutrophils and macrophages, which activate and damage intrinsic renal cells. While humoral immunity influences the patterns and severity of some forms of GN, in this model severe renal injury is driven by cell-mediated immunity [3] and occurs independently

of autologous antibodies [4]. There is evidence that both Th1 [5] and Th17 [6] responses are pathogenic in experimental crescentic GN. Deficiencies in the key transcription factors, T-bet for Th1 cells [7] and retinoic acid-related orphan receptor-γt (Rorγt) for Th17

cells [8], result in significantly attenuated renal injury. Traditionally, Th2 cells have been considered essential for host protection from parasitic infections, while Tobramycin aberrant Th2 responses have been associated with allergy and asthma. In experimental crescentic GN, some Th2-associated cytokines are reno-protective [9]. The signal transducer and activation of transcription (STAT) proteins provide a direct link between cytokine receptors and cytokine induced gene transcription [10]. Activation of the interleukin (IL)-4 receptor on undifferentiated T cells results in the activation of STAT6 with expression of IL-4 related genes [11]. STAT6 is considered central to mounting effective Th2 responses, including the production of Th2 cytokines IL-4 and IL-5, and the key transcription factor GATA binding protein 3 (GATA3) [12]. STAT6-deficient mice have impaired Th2 immune responses, but otherwise are phenotypically normal and produce normal numbers of CD4+ T cells [13]. While early studies suggested that STAT6 was an absolute requirement for IL-4 production [14,15], subsequently it was demonstrated that STAT6-deficient mice can produce IL-4 in response to parasitic infection [16,17]. STAT6 deficiency is protective in several Th2-associated disease models, including allergic asthma [18,19] and eosinophilia with airway hypersensitivity [20].

Renal transplantation improves survival of patients with end-stag

Renal transplantation improves survival of patients with end-stage kidney disease (ESKD).1 However, there continues to be a disparity between availability of deceased donor kidneys and potential recipients. In Australia, acceptance of ESKD patients aged 70–74 years for renal replacement therapy increased from 390 per million population (pmp) in 2004, to 469 pmp in 2008.2 In addition, Rapamycin the proportion of potential recipients aged 65 years and

over awaiting renal transplantation has increased by 21% between 2005 to 2008.3,4 The Scientific Registry of Transplant Patients (SRTR; i.e. US transplant registry data) has recorded a similar increase of prevalent potential recipients aged ≥70 years on the deceased donor waiting

list, from 114 in 1990 to 2544 in 2004.5 Deceased donor rates in Australia have remained low at 11 donors pmp in 2009 (10 pmp in 2005), compared with 34 pmp in Spain, 24 pmp in the USA and 17 pmp in the UK.6,7 However, there has been an increase in acceptance of older donor kidneys in Australia, with the number of deceased donors aged ≥55 years increasing 1.8-fold between 2001–2003 to 2007–2009.7 Kidneys from older donors are associated with inferior graft outcomes including late graft loss, chronic allograft nephropathy and higher risk of cardiovascular mortality;8,9 this is partially offset by the reduction in mortality associated with reduced wait-list time. Between 2005 and 2009 in Australia, there was a 1.3-fold increase in the number of expanded criteria donors (ECD),7,14 defined as any learn more donor aged ≥60 years, or any donor aged 50–59 years, with two of the following three criteria: cerebrovascular accident (CVA) death, terminal creatinine > 133 µmol/L or hypertension.15 Although the concept of ECD focuses primarily on advanced donor age, other risk factors such as CVA, hypertension, diabetes and high serum creatinine are also taken into account.16,17 Gaber et al. reported an

increase in glomerulosclerosis with increasing donor age, which correlated with a similar increased risk of delayed graft CYTH4 function (DGF), graft loss and poorer graft function in kidneys transplanted from older donors.18 Multiple studies have demonstrated that recipients of ECD kidneys have better survival compared with potential recipients on the waiting list but long-term outcomes associated with ECD grafts remains unclear.19,20 In a retrospective study of 2845 French transplant recipients aged ≥60 years, ECD grafts were associated with poorer graft survival compared with non-ECD grafts.12 The difference in graft survival was 6.2% at 12 months and 14.2% at 5 years (adjusted relative risk of graft failure associated with ECD grafts compared with non-ECD grafts was 1.98, P < 0.01).

We investigated whether the 869 T > C, 915 G > C and −800 G > A p

We investigated whether the 869 T > C, 915 G > C and −800 G > A polymorphisms of TGF-β1 are associated with diabetic nephropathy (DN). Methods:  Polymorphisms were genotyped in 439 type 2 diabetes mellitus patients, 233 with diabetic nephropathy (DN+) and 206 without (DN–). The sample was characterized

for relevant clinical and biochemical parameters. Results:  The 869 T > C (P = 0.016; odds ratio (OR) = 1.818, 95% confidence interval (CI) = 1.128–2.930) and the Talazoparib ic50 915 G > C polymorphisms (P = 0.008, OR = 4.073, 95% CI = 1.355–12.249) were associated with diabetic nephropathy. The 869 T > C variant was associated with total cholesterol levels: CC + CT genotypes had a mean cholesterol concentration of 5.62 ± 1.40 mmol/L vs a mean concentration Enzalutamide of 5.15 ± 1.40 mmol/L for the TT genotype (P = 0.011). Triglycerides were also higher in CC + CT genotypes (2.49 ± 1.56 mmol/L) in comparison with TT homozygotes (2.1 ± 1.22 mmol/L, P = 0.042). Multivariate logistic regression showed that the polymorphisms 869 T > C and 915 G > C were independent predictors for DN (P = 0.049 and 0.046, respectively). Conclusion:  The 869 T > C and 915 G > C polymorphisms within the TGF-β1 gene were associated with DN+. Lower cholesterol and triglycerides levels were observed in TT homozygotes for the 869 T > C

polymorphism. The TGF-β1 869 T allele seems to confer protection against DN+. “
“Aim:  Whether the burden of advanced oxidation protein products (AOPP) accumulation, a marker of oxidative stress, is affected by dialysis modality remains unclear. We compared the serum levels of AOPP in patients on haemodialysis (HD) and continuous ambulatory MTMR9 peritoneal dialysis (CAPD) and tested the hypothesis that an accumulation of AOPP was

an independent risk factor for cardiovascular disease. Methods:  This was a cross-section study. A total of 2095 patients (1539 HD, 556 CAPD) were recruited from the nine largest dialysis centres in China. Persons in medical centres for disease screening were selected as controls. Patients maintained on HD were dialyzed twice or thrice weekly. CAPD patients used lactate-buffered, glucose-containing solutions. The patients’ data were abstracted from the medical record. The serum levels of AOPP were determined by spectrophotometric detection. Results:  The levels of AOPP were significantly elevated in both HD and CAPD patients compared to healthy controls. Accumulation of AOPP was more significant in HD compared to CAPD population. Meanwhile, AOPP accumulation was associated with the presence of ischaemic heart disease (IHD) only in HD, but not CAPD patients. A higher proportion of IHD was found in the HD population among those with higher levels of AOPP in each category of age and irrespective of the presence or absence of high triglyceride. Multivariate regression analysis indicated that accumulation of AOPP was an independent risk factor for IHD in HD population.

To be more relevant to clinical conditions, we examined whether r

To be more relevant to clinical conditions, we examined whether rapid and large-scale changes in environmental temperature affect micturition patterns in conscious rats (Fig. 2). The rat cystometry investigation system was quickly moved from the room (27 °C) into a refrigerator (4 °C). The sudden environmental change induced an increase in urinary frequency (Fig. 3, Phase 1), but the DNA Damage inhibitor urinary frequency gradually settled down (Fig. 3, Phase 2).15 This observation indicated that the sudden cold stress induced an increase in urinary frequency, which settled down once the rats became acclimatized to the cold environment. When we moved these cystometry systems

back to normal room temperature (27 °C), the cystometric pattern returned to normal (Fig. 3). We also measured the urine volume by calculation of the infusion and micturition volumes; the results indicted that there was no increase in urinary output (unpublished data). This observation suggested that cold stress induces an increase in urinary frequency

without a concomitant increase in urinary output in rats. To determine the mechanism of the cold stress-induced increase in urinary frequency, we examined the parasympathetic pathway because we usually use anticholinergic selleckchem drugs for urinary frequency, especially in patients with bladder overactivity.16 We administered the non-selective anticholinergic drug atropine at a dose of 3 mg/kg (this dose was determined based on a pilot study) before cold stress during rat cystometry. However, we could not suppress the increase in urinary frequency associated with cold stress tuclazepam (Fig. 4a,b, unpublished data). A recent study showed that in tropical men acclimatized to the Antarctic environment, exposure to cold for long durations caused increased excretion of urinary epinephrine, norepinephrine, and salivary cortisol, all of which were associated with significant autonomic changes in heart rate and blood pressure.2 Based on these observations, we measured

blood pressure during cold stress. Sudden cold stress induced a significant elevation of blood pressure, but this elevation become non-significant after 30 min.17 This observation implied that cold stress induces elevation of blood pressure, which returns to normal once the rats become acclimatized to the cold environment. This phenomenon was very similar to the changes in urinary frequency pattern discussed previously.15 Clinically, we sometimes administer α1 adrenergic receptor (AR) blockers to patients with hypertension or those with benign prostatic hyperplasia.18 Chen et al.17 examined the changes in blood pressure associated with the administration of α1-AR blockers (silodosin: α1A selective AR blocker, naftopidil: α1D selective AR blocker, tamsulosin: α1A/D selective AR blocker), and these drugs were shown to prevent increases in blood pressure.

The supersaturation of extracellular fluids with

respect

The supersaturation of extracellular fluids with

respect to calcium and phosphate has demanded the evolution of mechanisms to counteract and inhibit ectopic deposition this website of mineral outside bone. The propensity to pathological calcification is thus governed by the balance between factors promoting or inhibiting this process. The phospho-glycoprotein fetuin-A (Fet-A) is a key systemic mineral chaperone and inhibitor of soft-tissue and vascular calcification.[5] Fet-A is synthesized mainly in the liver where it is glycosylated and secreted into plasma, circulating at relatively high concentrations. Fet-A knockout mice show a variety of problems associated with ectopic mineral deposition and abnormal (but

not absent) bone development, together with metabolic complications depending on the model.[6-8] In patients with chronic kidney disease (CKD), Fet-A deficiency has been associated with increased arterial calcification scores and higher mortality rates.[9-11] However, data on serum total Fet-A concentrations see more are difficult to interpret because of analytical issues and conflicting data.[12, 13] Recent investigation suggests a more complicated and dynamic control system for this protein. In concert with other acidic serum proteins, Fet-A mediates the formation and stabilization of high molecular weight colloidal complexes of calcium phosphate mineral termed calciprotein particles (CPP).[14] Analogous to the way in which apoplipoproteins surround and solubilize their lipid cargo, BCKDHA CPP provide a pathway for the transport of mineral nanocrystals and their clearance from the circulation by the mononuclear phagocytic system.[15] Previous work in rats suggests that CPP may originate

from the bone-remodelling compartment,[16] but they may also form spontaneously in other calcific micro-environments.[17-19] Circulating CPP burden can be inferred by assessing the apparent reduction serum Fet-A concentration (reduction ratio, RR) after high-speed centrifugation.[20] Inflammation has been identified as a key driver of ectopic mineralization.[21] Macrophage-derived pro-inflammatory cytokines such as interleukin-1α, interleukin-6, tumour necrosis factor-α and transforming growth factor-β have been shown to induce the transformation of vascular smooth muscle cells (VSMC) to a synthetic osteogenic phenotype. These osteochondrocytic-like VSMC extrude calcium phosphate crystal-laden matrix vesicles that nucleate mineralization of the vascular extracellular matrix.[22, 23] Importantly, calcium phosphate nanocrystals are themselves powerfully pro-inflammatory to macrophage, and themselves promote VSMC mineralization, potentiating a vicious cycle of inflammation and calcification.

After a single washing step in 1 × PBS and centrifugation, pellet

After a single washing step in 1 × PBS and centrifugation, pelleted cells were resuspended in 200 μL PBS with polyclonal anti-CR3-RP antibody (diluted

1 : 100), and mAb OKM1 (diluted 1 : 10). Control samples were resuspended in mAb TIB111 (diluted 1 : 10 in PBS). After 1-h incubation in ice, unbound antibodies were removed by centrifugation and cells were resuspended in a precise volume of YNB medium with amino acids containing 0.9%D-glucose (cell concentration, 107 mL−1). A 100-μL aliquot of this suspension was then applied to 96-well plates GSK2118436 purchase to undergo the adherence phase in biofilm formation for 30, 60, 90, and 120 min at 37 °C. At these time points, nonadherent cells were removed, adherent cells were washed with 1 × PBS in three washing steps and the viability of the adherent cells was evaluated by their ability to reduce 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) sodium salt to water-soluble formazan (Sigma-Aldrich). The parallel experiments were continued; after the adherence phase (90 min), nonadherent

cells were removed and adherent cells washed three times with 1 × PBS. Adherent cells were then overlaid with 100 μL of the new YNB medium and incubation continued at 37 °C for 48 h. The viability of the mature biofilm was evaluated as described above. Every experiment was performed in five parallel buy Palbociclib wells and performed twice. The results were expressed as mean±SD.

Results were calculated as average±SD. Statistical significance in the difference between the samples was compared using Student’s t-test. A P-value of <0.05 was considered ADAMTS5 significant, a P-value of <0.01 highly significant and a P-value of <0.001 extremely significant. Although the formation of a biofilm in the environment is a natural process important for the survival of many microorganisms, medical microbiology regards this complex structure as a serious complication during patient treatment or convalescence. Current trends in biofilm studies are aimed at possible ways to eliminate them, mainly via the application of antifungal agents (Kuhn et al., 2002; Al-Fattani & Douglas, 2004; Seidler et al., 2006; Borecká-Melkusová & Bujdáková, 2008). However, some authors have published different thoughts on biofilm treatment, such as photodynamic effects (Müller et al., 2007; Dovigo et al., 2009) or using antibodies (Rodier et al., 2003; Fujibayashi et al., 2009; Maza et al., 2009). In this study, we were focused on two different aspects: whether decreasing the ability of C. albicans to adhere to a plastic surface can reduce the production of the mature biofilm, and whether blocking the C. albicans surface antigen (CR3-RP) participating in adherence can significantly affect adherence, the first stage of biofilm formation. For experiments, one standard strain was selected, together with a C.

The effectiveness of this method was demonstrated in a multi-cent

The effectiveness of this method was demonstrated in a multi-centre randomized controlled trial in which 39 haemodialysis patients prone to intradialytic hypotension were treated using both fixed dialysate conductivity and https://www.selleckchem.com/products/apo866-fk866.html a dialysate conductivity derived from the conductivity kinetic model. There was a significant reduction in the intradialytic fall in systolic blood pressure (BP) when patients were dialysed using the conductivity kinetic model, with a trend towards better cardiovascular stability. Current evidence suggests that sodium modelling should be considered in patients prone to

intradialytic hypotension and those troubled by disequilibrium symptoms. Ultrafiltration refers to removal of water and constituent solutes, which thereby reduces plasma and extracellular fluid volume. It is accepted practice to perform a period of isolated UF before dialysis to improve tolerance of fluid removal in an overloaded patient. There have been few studies examining modelled UF alone, as it is usually examined Selumetinib cost in conjunction with sodium modelling. In

the aforementioned study by Zhou et al.,5 modelled UF with standard dialysate sodium resulted in a non-significant increase in intradialytic hypotensive episodes. Donauer et al.8 trialled 53 patients on 6 regimens of UF including constant, linear reduction, stepwise reduction and intermittent high UF rate interrupted by UF pauses, while simultaneously measuring Amisulpride relative blood volume. Linear modelled UF was

associated with an apparent reduction in hypotensive episodes, but this was not statistically significant. Stepwise and intermittent high UF models were associated with a significant increase in the frequency of symptomatic hypotension. Poor compliance with fluid restriction necessitates a higher rate of UF, and thereby increased risk of intradialytic hypotension. The level of patient compliance with fluid restriction has not been documented in the aforementioned studies. The absence of this information further limits any interpretation and recommendations that arise from these studies. Based on this limited evidence, nonlinear UF modelling alone may not be tolerated by some patients, and is best avoided in those prone to intradialytic hypotension. There are limited data to support linear modelling of UF as a method of avoiding intradialytic hypotension. Potassium is central to cardiac pacemaker rhythmicity, neuromuscular excitability and maintenance of resting cell membrane potential. Both hypokalaemia and hyperkalaemia predispose to cardiac arrhythmias.9 A higher dialysate potassium concentration is recommended for patients on digitalis therapy. Hyperkalaemia in the dialysis population is independently associated with higher all-cause and cardiovascular mortality.9 Both the rapid fall in serum potassium early in dialysis and hypokalaemia late in dialysis are arrhythmogenic.