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Background: Dietary sodium plays an important role in body fluid homeostasis and the development of cardiovascular (CV) disease in maintenance hemodialysis (HD) patients. Processed foods disproportionately contribute sodium to the diet, yet the influence of food type and purchase location on sodium intake and cardiovascular disease remain unknown in HD patients. Methods: Sixty HD patients were recruited. Four diet recalls (2 each on a dialysis day (DD) and non-dialysis day (NDD)) were collected from each patient using the USDA 5-pass method. Intake was analyzed using diet analysis software (Nutritionist Pro), separated by purchase location (store, fast food, full-service, and other), and grouped by similar characteristics into eight categories according to NHANES. The ratio of sodium to energy (Na:kcal) was calculated. On a separate NDD, CV function was assessed using arterial tonometry. Comparisons between variables on DD and NDD were made using paired t-test, stepwise regression was used to predict Na:kcal, and correlations were run among variables of interest using SPSS. Results: Overall, 70.96 ± 26.67% of all energy consumed was purchased at a traditional grocery store. HD patients consumed significantly more energy on a NDD as compared to DD (1,859.1 ± 714.9 vs. 1,670.8 ± 713.9, p < 0.01), primarily from beverages (203.7 ± 176.1 vs. 157.2 ± 120.4 kcal, p < 0.01), produce (207.3 ± 199.6 vs. 155.3 ± 137.8 kcal, p = 0.035), and deli foods (624.8 ± 299.5 vs 534.1 ± 317.9 kcal, p = 0.024). The Na: Kcal (1.73 ± 0.48 mg/kcal) was highest in fast food (2.18 mg/kcal), positively correlated with aortic and brachial blood pressures (p < 0.05 for all) and trended towards an association with aortic pulse wave velocity (r = 0.234, p = 0.09). When all purchase locations and food categories were entered into a Stepwise regression to predict Na: Kcal, only kcal from the deli category remained a significant predictor (R = 0.436, p < 0.01). Conclusions: The Na: Kcal, but not the food category or purchase location, was significantly associated with CV health. These findings provide insight to help guide dietary counseling and suggest Na: Kcal may be an appropriate target for intervention from renal dietitians. [ABSTRACT FROM AUTHOR]

Background: Policies regarding eating during hemodialysis (HD) treatment remain a controversial topic due to concerns about postprandial hemodynamics and symptom development. These latter factors are influenced by the quantity, consistency, and composition of the food consumed. However, what patients choose to eat during treatment (when allowed) has not been previously described. Methods: Therefore, we analyzed the intradialytic dietary intake of 49 HD patients, who participated in the validation of a gastrointestinal symptom questionnaire at a clinic that allowed patients to eat during treatment. Dietary intake was measured by diet recall and analyzed by nutrient analysis software (Nutritionist Pro) during two HD treatments separated by three weeks. Results: 67.3% of patients who completed the study chose to eat (average intake >0 kcal) during at least one of the two treatments. Of those patients who chose to eat, average intake during a single treatment was 164.0 ± 168.1 (range 7.7 to 856.5) Kcal, 10.1 ± 9.0 g protein, 21.2 ± 24.6 g carbohydrate, 4.7 ± 6.3 g of fat, and 217.9 ± 167.9 ml of fluid. The majority of carbohydrate intake came from sugar (11.7 ± 14.6 g). Average sodium intake was 176.9 ± 386.9 mg, with a sodium-to-kcal ratio of 1.1 mg/kcal. Patients who ate, but did not consume a supplement (n = 15), consumed significantly less protein than those receiving a supplement (p < 0.05). Intakes of energy, protein, carbohydrate, fat, and sodium were correlated (p < 0.05) between treatment one and treatment two. Water or ice, oral nutrition supplements, candy, cookies, and crackers were among the most frequently consumed items. Conclusions: In summary, we found that approximately 2/3 of patients chose to eat during treatment when dialyzing at a clinic where this practice was allowed. While most meals were moderately sized and consistent across treatments, the types of items being consumed suggest an opportunity for counseling as well as clinic policy makers. [ABSTRACT FROM AUTHOR]

Topic: Nutrition, Inflammation, and Metabolism. Background: Patients with renal failure undergoing maintenance hemodialysis (MHD) therapy suffer from a number of comorbidities including skeletal muscle loss, reduced physical function, a significantly increased fall risk, and reduced quality of life (QOL). Therefore, interventions to combat these co-morbidities are needed. Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite of the amino acid leucine that has been shown to improve lean mass and physical function in the elderly and clinical populations, but had not previously been studied in MHD patients. Therefore, the purpose of this study was to investigate the efficacy of HMB to combat co-morbidities in this population. Methods: We performed a double-blind, placebo-controlled, randomized trial to assess the effects of daily HMB supplementation on co-morbidities in MHD patients. MHD patients were recruited and assigned to either daily supplementation with HMB (n = 16) or placebo (n = 17) for 6 months. Measurements of body composition, bone density, strength, physical function, fall risk, quality of life, and standard blood parameters were measured at baseline and 6 months. In addition, blood was drawn at baseline, 3, and 6 months to measure compliance. Results: No significant effects of HMB on body composition, bone density, strength, physical function, fall risk, quality of life, or blood parameters were found using an intent-to-treat analysis. However, upon analysis of plasma HMB concentrations, 5 of 16 patients (31%) in the HMB group were found to be non-compliant at 3 or 6 months. Therefore, we performed a per-protocol analysis with compliant participants only. While there were trends for improvements in the HMB group for several measures related to physical function, these did not reach statistical significance. Conclusions: As a whole, these results do not support the efficacy of HMB to attenuate co-morbid conditions in MHD patients. Moreover, it highlights the need for future interventions targeted at reducing pill burden and improving pill compliance in this population. [ABSTRACT FROM AUTHOR]

Objective: Internet search engines and social media websites are prominent and growing sources of dietary information for people with chronic kidney disease (CKD) and their healthcare providers. However, nutrition therapy for CKD is undergoing a paradigm shift, which may lead to inconsistent advice for managing hyperphosphatemia. The aim of this study was to summarize and evaluate online resources for phosphorus-specific nutrition therapy., Design and Methods: Patient-facing resources were collected from Google, Yahoo, and Facebook in June-July 2021. Using nine independent search terms, the first 100 hits were reviewed. Dietary advice for food types, food groups, food subgroups, and individual food items was categorized as "restricted," "recommended," "mixed," and "not mentioned." Information on publication date, source, and author(s), phosphorus bioavailability, and demineralization were also collected., Results: After removing duplicates, 199 resources from Google and Yahoo and 33 from Facebook were reviewed. Resources ranged from 2005 to 2021 and were primarily authored by registered dietitians and medical doctors (65% and 31%, respectively). Dietary advice mostly focuses on restricting high-phosphorus foods and phosphorus additive-based processed foods. Dietary restrictions were generally consistent with the traditional low-phosphorus diet, which targets whole grains, dairy, and plant-based protein foods, although major inconsistencies were noted. Phosphorus bioavailability and demineralization were rarely mentioned (16% and 8%, respectively). Similar findings were found on Facebook, but the limited number of resources limited meaningful comparisons., Conclusion: Results showed that online resources for phosphorus-specific nutrition therapy are highly restrictive of heart-healthy food items and contain significant inconsistencies. Given the widespread and increasing use of online resources by people with CKD and health care professionals to inform dietary choices, efforts are urgently needed to establish consensus for phosphorus-specific nutrition therapy. Until then, the findings of this study provide a basis for increasing awareness of the potential for confusion arising from online resources., (Copyright © 2024 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

While dialysis has been the prevailing treatment paradigm for patients with advanced chronic kidney disease (CKD), emphasis on conservative and preservative management in which dietary interventions are a major cornerstone have emerged. Based on high-quality evidence, international guidelines support the utilization of low-protein diets as an intervention to reduce CKD progression and mortality risk, although the precise thresholds (if any) for dietary protein intake vary across recommendations. There is also increasing evidence demonstrating that plant-dominant low-protein diets reduce the risk of developing incident CKD, CKD progression, and its related complications including cardiometabolic disease, metabolic acidosis, mineral and bone disorders, and uremic toxin generation. In this review, we discuss the premise for conservative and preservative dietary interventions, specific dietary approaches used in conservative and preservative care, potential benefits of a plant-dominant low-protein diet, and practical implementation of these nutritional strategies without dialysis., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Protein-energy wasting (PEW) is a key cause of functional impairment and poor health outcomes in people with chronic kidney disease. While PEW can be mitigated with nutrition therapy, it is a complex myriad of disorders with numerous interacting etiologies and corresponding presentations, which make it difficult to diagnose and manage in practice. A variety of scoring rubrics have been developed to facilitate malnutrition assessment. Although these tools have greatly benefited the recognition and treatment of PEW, the typical format of grading specified PEW indicators has the potential to overlook or overstate highly relevant individual-specific factors. This review presents a simple framework for malnutrition assessment that can be used to complement and evaluate conventional assessment tools. Unlike standard tools, which are designed to identify and rate malnutrition risk and severity, the malnutrition framework is conceptual model that organizes PEW assessment into three distinct, but interacting facets of PEW risk: nutrient balance, nutrition status, and malnutrition risk. The new framework encourages critical thinking about PEW risk that may help clinicians plan and interpret assessments to efficiently and effectively manage this condition., (Published by Elsevier Inc.)

Background & Aims: Protein energy wasting frequently affect hemodialysis patients and contribute to the development of overhydration. The objective of this study was to assess the effect of oral nutritional supplementation (ONS) combined with bioelectrical vector analysis (BIVA) on the nutritional and hydration status and the quality of life (QoL) in hemodialysis (HD) patients., Methods: Thirty-two chronic HD patients were included in a 6-month randomized pilot study. Patients in SUPL group received a simultaneous intervention consisting of a personalized diet, 245 mL/d ONS and dry weight adjustment through BIVA. Patients in CON group received a personalized diet and dry weight adjustment by BIVA. Anthropometrical, biochemical, dietary, QoL, handgrip strength (HGS) and bioimpedance measurements were performed. Malnutrition Inflammation Score (MIS) was applied., Results: At the end of the intervention, moderate undernutrition decreased by 43.8% in SUPL group while in CON group, severe undernutrition increased by 13% (p < 0.04 between groups). In the adjusted covariance analysis, SUPL compared to CON group, increased HGS (Δ 2.8 Kg vs Δ -1.8 Kg, p = 0.003), serum albumin (Δ 0.29 g/dL vs Δ -0.03 g/dL, p = 0.04) and serum transferrin (Δ 4.7 mg/dL vs Δ -0.7 mg/dL, p = 0.0007). The increase in QoL was significantly higher in SUPL group. Dry weight was achieved in 100% of patients in SUPL and 95% in CON group., Conclusions: ONS combined with BIVA for dry weight adjustment, improved nutritional status, QoL and achieved dry weight in HD patients., Competing Interests: Declaration of competing interest, (Copyright © 2022 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.)

Background and Objectives: Nutrition intervention is an essential component of kidney disease management. This study aimed to understand current global availability and capacity of kidney nutrition care services, interdisciplinary communication, and availability of oral nutrition supplements., Design, Setting, Participants, & Measurements: The International Society of Renal Nutrition and Metabolism (ISRNM), working in partnership with the International Society of Nephrology (ISN) Global Kidney Health Atlas Committee, developed this Global Kidney Nutrition Care Atlas. An electronic survey was administered among key kidney care stakeholders through 182 ISN-affiliated countries between July and September 2018., Results: Overall, 160 of 182 countries (88%) responded, of which 155 countries (97%) answered the survey items related to kidney nutrition care. Only 48% of the 155 countries have dietitians/renal dietitians to provide this specialized service. Dietary counseling, provided by a person trained in nutrition, was generally not available in 65% of low-/lower middle-income countries and "never" available in 23% of low-income countries. Forty-one percent of the countries did not provide formal assessment of nutrition status for kidney nutrition care. The availability of oral nutrition supplements varied globally and, mostly, were not freely available in low-/lower middle-income countries for both inpatient and outpatient settings. Dietitians and nephrologists only communicated "sometimes" on kidney nutrition care in ≥60% of countries globally., Conclusions: This survey reveals significant gaps in global kidney nutrition care service capacity, availability, cost coverage, and deficiencies in interdisciplinary communication on kidney nutrition care delivery, especially in lower-income countries., (Copyright © 2022 by the American Society of Nephrology.)

Purpose: To examine the acute influence of caffeine on post-exercise central blood pressures, arterial stiffness, and wave reflection properties., Methods: In a double-blind randomized placebo-controlled crossover study design, ten middle-aged males (55 ± 5 year) completed two exercise trials after ingestion of caffeine (400 mg) or placebo. Measurements were taken before and 30 min post-ingestion via cuff-based pulse wave analysis (PWA) and carotid-femoral pulse wave velocity (PWV). Participants performed a 40-min cycling bout at 70% HRmax with matched workloads between trials. PWA and PWV were reassessed 30 min post-exercise., Results: Prior to exercise, compared to placebo, caffeine increased brachial systolic blood pressure (bSBP) (+ 12.3 ± 2.4 mmHg; p = 0.004), brachial diastolic blood pressure (bDBP) (+ 7.7 ± 0.9 mmHg; p = 0.011), central systolic blood pressure (cSBP) (+ 11.1 ± 2.1 mmHg; p = 0.005) and central diastolic blood pressure (cDBP) (+ 7.6 ± 1.0 mmHg; p = 0.012). PWV was higher 30 min after pill ingestion (p = 0.021 for time) with a trend for a greater increase in caffeine (p = 0.074 for interaction). bSBP (p = 0.036) and cSBP (p = 0.007) were lower after exercise but remained higher (both p < 0.001) in caffeine compared to placebo. PWV remained higher (p = 0.023) after exercise in caffeine compared to placebo but was not influenced by exercise. At rest, augmentation pressure (AP) and index (AIx) were not influenced by caffeine ingestion. Conversely, AIx was lower (p = 0.009) after exercise in placebo only., Conclusion: In healthy and active middle-aged men, pre-exercise caffeine ingestion led to higher central and peripheral systolic blood pressures, PWV and AIx at 30 min post-exercise, indicating an increased left ventricular workload which may have implications for cardiovascular event risk.

Ongoing neuroinflammation may contribute to symptoms of autism spectrum disorder (ASD) in at least a portion of affected individuals. Mesenchymal stromal cells (MSCs) have demonstrated the capacity to modulate neuroinflammation, but safety and feasibility of MSC administration in children with ASD have not been well established. In this open-label, phase I study, 12 children with ASD between 4 and 9 years of age were treated with intravenous (IV) infusions of human cord tissue mesenchymal stromal cells (hCT-MSCs), a third-party MSC product manufactured from unrelated donor umbilical cord tissue. Children received one, two, or three doses of 2 × 10 6 cells per kilogram at 2-month intervals. Clinical and laboratory evaluations were performed in person at baseline and 6 months and remotely at 12 months after the final infusion. Aside from agitation during the IV placement and infusion in some participants, hCT-MSCs were well tolerated. Five participants developed new class I anti-human leukocyte antigen (HLA) antibodies, associated with a specific lot of hCT-MSCs or with a partial HLA match between donor and recipient. These antibodies were clinically silent and not associated with any clinical manifestations to date. Six of 12 participants demonstrated improvement in at least two ASD-specific measures. Manufacturing and administration of hCT-MSCs appear to be safe and feasible in young children with ASD. Efficacy will be evaluated in a subsequent phase II randomized, placebo-controlled clinical trial., (© 2020 The Authors. STEM CELLS TRANSLATIONAL MEDICINE published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.)

Objective: Patients undergoing hemodialysis (HD) have high protein and energy requirements, and protein-energy wasting is common and associated with poor outcomes. Eating during dialysis may improve nutritional status by counteracting the catabolic effects of HD treatment; but eating during HD may be discouraged because of concerns of postprandial hypotension. However, little data are available to support this practice. In this study, we hypothesized that high-protein meals during HD do not lead to symptomatic intradialytic hypotension events., Design: A 9-week, nonrandomized, parallel-arm study., Setting: A single in-center HD clinic., Subjects: Eighteen patients undergoing HD from 2 shifts completed the study. Patients were aged 62 ± 16 years with dialysis vintage of 3.4 ± 2.6 years., Intervention: Patients in the intervention group (n = 9) undergoing HD received meals of ∼30 g protein and ∼1/3 daily recommended intakes of sodium, potassium, phosphorus, and fluid during dialysis for 25 consecutive HD sessions. The control group (n = 9) completed all aspects of the study including a visit by study personnel but were not given meals. The 25 consecutive sessions before the start of the intervention/control phase were used as a baseline comparison for each patient., Main Outcome Measure: Symptomatic hypotension event frequency., Results: In the intervention arm, there were 19 symptomatic hypotension events in 5 patients prestudy and 18 events in 6 patients during the study. In the control arm, there were 16 events in 7 patients prestudy and 13 events in 7 patients during the study. Change in the frequency of symptomatic hypotension events from prestudy to during study was not different between groups (P = .71). There was no effect of meals on nutritional status, but patients reported positive attitudes toward receiving meals during dialysis., Conclusion: High-protein meals during HD did not increase symptomatic hypotension events. Larger, longer term studies are needed to confirm these results and evaluate whether high-protein meals on dialysis benefit nutritional status and clinical outcomes., (Copyright © 2018 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Steroid refractory inflammation is an unmet medical need in the management of inflammatory diseases. Thus, mechanisms, improving steroid sensitivity and simultaneously decreasing inflammation have potential therapeutic utility. The FK506-binding protein 51 (FKBP51) is reported to influence steroid sensitivity in mental disorders. Moreover, biochemical data highlight a connection between FKBP51 and the IKK complex. The aim of this study was to elucidate whether FKBP51 inhibition had utility in modulating steroid resistant inflammation by increasing the sensitivity of the glucocorticoid receptor (GR) signalling and simultaneously inhibiting NFκB-driven inflammation. We have demonstrated that FKBP51 silencing in a bronchial epithelial cell line resulted in a 10-fold increased potency for dexamethasone towards IL1beta-induced IL6 and IL8, whilst FKBP51 over-expression of FKBP51 reduced significantly the prednisolone sensitivity in a murine HDM-driven pulmonary inflammation model. Immunoprecipitation experiments with anti-FKBP51 antibodies, confirmed the presence of FKBP51 in a complex comprising Hsp90, GR and members of the IKK family. FKBP51 silencing reduced NFκB (p50/p65) nucleus translocation, resulting in reduced ICAM expression, cytokine and chemokine secretion. In conclusion, we demonstrate that FKBP51 has the potential to control inflammation in steroid insensitive patients in a steroid-dependent and independent manner and thus may be worthy of further study as a drug target., (© 2018 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Objective: To compare the incidence of complications (wound, infection, and nonunion) among those patients treated with closed, percutaneous, and open intramedullary nailing for closed tibial shaft fractures., Design: Retrospective review., Setting: Multiple trauma centers., Patients: Skeletally mature patients with closed tibia fractures amenable to treatment with an intramedullary device., Intervention: Intramedullary fixation with closed, percutaneous, or open reduction., Main Outcome Measurements: Superficial wound complication, deep infection, nonunion., Results: A total of 317 tibial shaft fractures in 315 patients were included in the study. Two-hundred fractures in 198 patients were treated with closed reduction, 61 fractures in 61 patients were treated with percutaneous reduction, and 56 fractures in 56 patients were treated with formal open reduction. The superficial wound complication rate was 1% (2/200) for the closed group, 1.6% (1/61) for the percutaneous group, and 3.6% (2/56) for the open group with no statistical difference between the groups (P = 0.179). The deep infection rate was 2% (4/200) for the closed group, 1.6% (1/61) for the percutaneous group, and 7.1% (4/56) for the open group with no significant difference between the groups (P = 0.133). Nonunion rate was 5.0% (10/200) for the closed group, 4.9% (3/61) for the percutaneous group, and 7.1% (4/56) for the open group, with no statistical difference between the groups (P = 0.492)., Conclusions: This is the largest reported series of closed tibial shaft fractures nailed with percutaneous and open reduction. Percutaneous or open reduction did not result in increased wound complications, infection, or nonunion rates. Carefully performed percutaneous or open approaches can be safely used in obtaining reduction of difficult tibial shaft fractures treated with intramedullary devices., Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background and Objectives: Eating during hemodialysis treatment remains a controversial topic. It is perceived that more restrictive practices in the United States contribute to poorer nutritional status and elevated mortality compared with some other parts of the world. However, in-center food practices in the United States have not been previously described., Design, Setting, Participants, & Measurements: In 2011, we conducted a survey of clinic practices and clinician (dietitian, facility administrator, and medical director) opinions related to in-center food consumption within a large dialysis organization. After the initial survey, we provided clinicians with educational materials about eating during treatment. In 2014, we performed a follow-up survey. Differences in practices and opinions were analyzed using chi-squared tests and logistic regression., Results: In 2011, 343 of 1199 clinics (28.6%) did not allow eating during treatment, 222 clinics (18.2%) did not allow drinking during treatment, and 19 clinics (1.6%) did not allow eating at the facility before or after treatment. In 2014, the proportion of clinics that did not allow eating during treatment had declined to 22.6% (321 of 1422 clinics), a significant shift in practice (P<0.001). Among the 178 (6.8%) clinics that self-reported that eating was "more allowed" in 2014, the main reason for this shift was an increased focus on nutritional status. Among clinicians, a higher percentage encouraged eating during treatment (53.1% versus 37.4%; P<0.05), and facility administrators and medical directors were less concerned about the seven reasons commonly cited for restricting eating during treatment in 2014 compared with 2011 (P<0.05 for all)., Conclusions: We found that 28.6% and 22.6% of hemodialysis clinics within the United States restricted eating during treatment in 2011 and 2014, respectively, a rate more than double that found in an international cohort on which we previously published. However, practices and clinician opinions are shifting toward allowing patients to eat. Additional research is warranted to understand the effect that these practices have on patient outcomes and outline best practices., (Copyright © 2016 by the American Society of Nephrology.)

Providing food or nutrition supplements during hemodialysis (HD) may be associated with improved nutritional status and reduced mortality; however, despite these potential benefits, eating practices vary across countries, regions, and clinics. Understanding present clinic practices and clinician experiences with eating during HD may help outline best practices in this controversial area. Therefore, the objective of this study was to examine clinical practices and experiences related to eating during HD treatment. We surveyed clinicians about their clinic practices during the 2014 International Society of Renal Nutrition and Metabolism Conference. We received 73 responses from six continents. Respondents were primarily dietitians (71%) working at units housed in a hospital (63%). Sixty-one clinics (85%) allowed patients to eat during treatment, with 47 of these patients (65%) actively encouraging eating. Fifty-three clinics (73%) provided food during HD. None of the nine clinics from North America, however, provided food during treatment. The majority (47 clinics; 64%) provided supplements during treatment. Clinics in the hospital setting were more likely to provide food during treatment, whereas outpatient clinics were less likely to provide nutrition supplements (P≤ 0.05 for both). We also asked clinicians about their experience with six commonly cited reasons to restrict eating during treatment using a four-point scale. Clinicians responded they observed the following conditions "rarely" or "never": choking (98%), reduced Kt/V (98%), infection control issues (96%), spills or pests (83%), gastrointestinal issues (71%), and hypotension (62%). Our results indicate that while eating is common during treatment in some areas, disparities may exist in global practices, and most of the proposed negative sequelae of eating during HD are not frequently observed in clinical practice. Whether these disparities in practice can explain global differences in albumin warrants further research to help inform decisions regarding eating during HD., (Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: End-stage renal disease patients experience increased prevalence of cardiovascular disease. Heart-artery interaction may be shifted, impacting blood pressure lability, and exercise tolerance. The coupling ratio consists of the ratio of indexed arterial elastance (EaI, arterial load) to ElvI, a measure of cardiac contractility or stiffness. Our purpose was to explore the relationship between elastances and functional capacity. We hypothesized that arterial stiffness (central pulse wave velocity, PWV) and elastances would be correlated to shuttle walk time., Methods: We used applanation tonometry, ultrasonography, and a shuttle walk test to evaluate our hypothesis. Spearman's correlations were used to assess relationships between variables. Block regression was also performed., Results: Forty-two subjects on maintenance hemodialysis participated. Average age=44±5 years, body surface area=2.01 kg/m(2). Mean EaI=4.45 and mean ElvI=6.89; the coupling ratio=0.82. Mean aortic pulse pressure=51 mmHg and PWV=9.6 m/s. PWV(r=-0.385) and EaI (r=-0.424) were significantly and inversely related to walking time while stroke volume index (SVI) was positively correlated to shuttle walk time (r=0.337), p<0.05 for all., Conclusions: We conclude that, like other clinical populations, both arterial and heart function predict walking ability and represent potential targets for intervention; arterial stiffness and SVI are strongly related to shuttle walk time in patients with ESRD., (Copyright © 2013 S. Karger AG, Basel.)

Polyclonal autoantibodies against human GM-CSF (granulocyte/macrophage colony-stimulating factor) are a hallmark of PAP (pulmonary alveolar proteinosis) and several other reported autoimmune diseases. MB007 is a high-affinity anti-(human GM-CSF) autoantibody isolated from a patient suffering from PAP which shows only modest neutralization of GM-CSF bioactivity. We describe the first crystal structure of a cytokine-directed human IgG1λ autoantibody-binding fragment (Fab) at 1.9 Å (1 Å=0.1 nm) resolution. Its CDR3-H substantially differs from all VH7 germline IgG1 structures reported previously. We derive a reliable model of the antigen-autoantibody complex by using NMR chemical shift perturbation data in combination with computational methods. Superposition of the modelled complex structure with the human GM-CSF-GM-CSF ternary receptor complex reveals only little overlap between receptor and Fab when bound to GM-CSF. Our model provides a structural basis for understanding the mode of action of the MB007 autoantibody.

Stimulation of CXC-type chemokine receptor 2 (CXCR2)-transfected cells by Gro-alpha or IL-8 induced (i) CXCR2 internalization, (ii) phosphorylation of ERK1/2 (pERK) and (iii) translocation of nuclear factor of activated T cells (NFAT) into the nucleus. Employing high content screening (HCS; i.e. fluorimetric imaging combined with image analysis) these three ligand-induced events were quantified by using a CXCR2-specific antibody, an antibody recognizing phosphorylated ERK1/2 (pERK) and a red fluorescent protein (RFP) in fusion to transiently overexpressed NFAT, respectively. As an RFP, we applied a recently developed mutant of an Entacmaea quadricolor fluorescent protein with favorable properties for HCS, such as high fluorescence brightness, photostability, large Stokes shift, and stability with regard to formaldehyde. Receptor internalization was closely coupled with ERK signalling both when analyzed in regard of stimulation by physiological CXCR2 ligands and when observed in the presence of antagonistic test compounds. A means of increasing the throughput or of broadening the pharmacological characterization of test compounds is the use of multiplexed imaging. Indeed, CXCR2 internalization could be multiplexed with the NFAT nuclear translocation by fixation at approximately 45 min after Gro-alpha stimulation. This multiplexing demonstrated that Gro-alpha-induced CXCR2 internalization was tightly correlated with Gro-alpha-induced NFAT translocation, also on the single cell level. The analysis of ERK phosphorylation, NFAT translocation and receptor internalization enabled the profiling of antagonistic test compounds with respect to G-protein signalling and possible receptor desensitization liabilities.

To study CXCR2 modulated arrestin redistribution, the authors employed arrestin as a fusion protein containing either the Aequorea victoria-derived enhanced green fluorescent protein (EGFP) or a recently developed mutant of eqFP611, a red fluorescent protein derived from Entacmaea quadricolor. This mutant, referred to as RFP611, had earlier been found to assume a dimeric quarternary structure. It was therefore employed in this work as a "tandem" (td) construct for pseudo-monomeric fusion protein labeling. Both arrestin fusion proteins, containing either td-RFP611 (Arr-td-RFP611) or enhanced green fluorescent protein (EGFP; Arr-EGFP), were found to colocalize with internalized fluorescently labeled Gro-alpha a few minutes after Gro-alpha addition. Intriguingly, however, Arr-td-RFP611 and Arr-EGFP displayed distinct cellular distribution patterns in the absence of any CXCR2-activating ligand. Under these conditions, Arr-td-RFP611 showed a largely homogeneous cytosolic distribution, whereas Arr-EGFP segregated, to a large degree, into granular spots. These observations indicate a higher sensitivity of Arr EGFP to the constitutive activity of CXCR2 and, accordingly, an increased arrestin redistribution to coated pits and endocytic vesicles. In support of this interpretation, the authors found the known CXCR2 antagonist Sch527123 to act as an inverse agonist with respect to Arr-EGFP redistribution. The inverse agonistic properties of Sch527123 were confirmed in vitro in a guanine nucleotide binding assay, revealing an IC(50) value similar to that observed for Arr-EGFP redistribution. Thus, the redistribution assay, when based on Arr-EGFP, enables the profiling of antagonistic test compounds with respect to inverse agonism. When based on Arr-td-RFP611, the assay may be employed to study CXCR2 agonism or neutral antagonism.

We have investigated activation of nuclear factor-kappa B (NF-kappa B) in the process of primary B cell differentiation in vitro. In this system, NF-kappa B is strongly induced when B cells develop from the pre-B cell to the immature B cell stage. Unlike the typical NF-kappa B activation in response to exogenous stimuli, induction proceeds with a slow time course. NF-kappa B induction is only observed in B cells that undergo differentiation, not in Rag2-deficient cells. Nuclear DNA binding complexes predominantly comprise p50/RelA heterodimers and, to a lesser extent, c-Rel-containing dimers. The increase in NF-kappa B binding activity is accompanied by a slow and steady decrease in I kappa B beta protein levels. Interestingly, absolute RelA protein levels remain unaffected, whereas RelB and c-Rel synthesis is induced. The reason for preferential nuclear translocation of RelA complexes appears to be selective inhibition by the I kappa B beta protein. I kappa B beta can efficiently inhibit p50/RelA complexes, but has a much reduced ability to interfere with p50/c-Rel DNA binding both in vitro and in vivo. Interestingly, p50/RelB complexes are not at all targeted by I kappa B beta, and coimmunoprecipitation experiments show no evidence for an association of I kappa B beta and RelB in vivo. Consistent with these observations, I kappa B beta cotransfection can inhibit p50/RelA-mediated trans-activation, but barely affects p50/RelB mediated trans-activation.

NF-kappa B was originally identified as a B cell-specific nuclear factor binding to the intronic kappa-light-chain enhancer element. It is found constitutively in the nucleus of mature B and plasma cells. In other cell types including pre-B cells, NF-kappa B is sequestered in the cytoplasm but can be induced by a variety of stimuli. In contrast to essentially all other mature B cells and plasma cell lines, the S107 plasmacytoma cell line lacks both constitutive and inducible kappa B-binding activity. A molecular characterization of the defect in these S107 cells suggests that the primary defect lies in the signal transduction pathway leading to NF-kappa B induction. Ectopic expression of RelB after stable transfection of these cells restores constitutive nuclear kappa B-binding activity. Moreover, kappa B-dependent transcription is also restored. Finally we demonstrate, that in contrast to parental S107 cells, the stable RelB transfectants have also regained the ability to specifically demethylate a transfected immunoglobulin kappa-locus. These data suggest that RelB is critically involved in both B cell-specific transcription and demethylation directed by the intronic kappa-enhancer element.

NF-kappaB and activator protein 1 (AP-1) are dimeric transcription factors involved in transcriptional regulation in many cells, including neurons. We have examined their activity during mouse cerebellum development, a postnatal process starting just after birth and completed by the fourth postnatal (PN) week. The activity of these factors was analyzed by binding of nuclear extracts to a synthetic oligonucleotide representing the kappaB site of human immunodeficiency virus or the AP-1 site of the urokinase promoter. NF-kappaB activity was observed from 7 PN, was restricted to the developing cerebellum, and was not observed in the early postnatal neocortex and hippocampus. On the other hand, AP-1 activity was not found in cerebellum but was present in both neocortex and hippocampus. Moreover, a kappaB-driven transgene was found to be increasingly expressed in the cerebellum from 5 PN to 10 PN but not in the adult. The regulation of NF-kappaB activation in mouse cerebellum was analyzed by intraperitoneal injection of glutamate receptor antagonists to 9 PN mice, which abolished NF-kappaB-binding activity, suggesting an endogenous loop of glutamate receptor activation. Glutamate receptor agonists, on the other hand, induced NF-kappaB nuclear translocation in the cerebellum of 5 PN mice, which is a stage in which NF-kappaB is not yet endogenously activated. This effect was specific for NF-kappaB and not observed for AP-1. In adult mice, NF-kappaB activity was absent in the cerebellum and was not induced by intraperitoneal injection of glutamate receptor agonists. These data show that NF-kappaB is specifically activated during cerebellum development and indicate an important role of glutamate receptors in this process.

The immunoglobulin kappa gene is specifically demethylated during B-cell maturation in a process which utilizes discrete cis-acting modules such as the intronic kappa enhancer element and the matrix attachment region (MAR). While any MAR sequence is sufficient for this reaction, mutation analysis indicates that tissue specificity is mediated by kappaB binding sequences within the kappa intronic enhancer. The plasmacytoma cell line S107 lacks kappaB binding activity and fails to demethylate the kappa locus. However, B-cell specific demethylation is restored by the introduction of an active kappaB binding protein gene relB. This represents the first demonstration of a trans-acting factor involved in cell-type-specific demethylation, and suggests that the same protein-DNA recognition system used for transcription may also contribute to the earlier developmental events that bring about activation of the kappa locus.