Microgel that swims to the beat of light.

Complementary to the quickly advancing understanding of the swimming of microorganisms, we demonstrate rather simple design principles for systems that can mimic swimming by body shape deformation. For this purpose, we developed a microswimmer that could be actuated and controlled by fast temperature changes through pulsed infrared light irradiation. The construction of the microswimmer has the following features: (i) it is a bilayer ribbon with a length of 80 or 120 [Formula: see text]m, consisting of a thermo-responsive hydrogel of poly-N-isopropylamide coated with a 2-nm layer of gold and equipped with homogeneously dispersed gold nanorods; (ii) the width of the ribbon is linearly tapered with a wider end of 5 [Formula: see text]m and a tip of 0.5 [Formula: see text]m; (iii) a thickness of only 1 and 2 [Formula: see text]m that ensures a maximum variation of the cross section of the ribbon along its length from square to rectangular. These wedge-shaped ribbons form conical helices when the hydrogel is swollen in cold water and extend to a filament-like object when the temperature is raised above the volume phase transition of the hydrogel at [Formula: see text]. The two ends of these ribbons undergo different but coupled modes of motion upon fast temperature cycling through plasmonic heating of the gel-objects from inside. Proper choice of the IR-light pulse sequence caused the ribbons to move at a rate of 6 body length/s (500 [Formula: see text]m/s) with the wider end ahead. Within the confinement of rectangular container of 30 [Formula: see text]m height and 300 [Formula: see text]m width, the different modes can be actuated in a way that the movement is directed by the energy input between spinning on the spot and fast forward locomotion.

Incidence, Risk Factors, and Outcome of Acute Kidney Injury in Neurocritical Care.

PURPOSE: Acute kidney injury (AKI) is a severe complication in medical and surgical intensive care units accounting for a high morbidity and mortality. Incidence, risk factors, and prognostic impact of this deleterious condition are well established in this setting. Data concerning the neurocritically ill patients is scarce. Therefore, aim of this study was to determine the incidence of AKI and elucidate risk factors in this special population. METHODS: Patients admitted to a specialized neurocritical care unit between 2005 and 2011 with a length of stay above 48 hours were analyzed retrospectively for incidence, cause, and outcome of AKI (AKI Network-stage ≥2). RESULTS: The study population comprised 681 neurocritically ill patients from a mixed neurosurgical and neurological intensive care unit. The prevalence of chronic kidney disease (CKD) was 8.4% (57/681). Overall incidence of AKI was 11.6% with 36 (45.6%) patients developing dialysis-requiring AKI. Sepsis was the main cause of AKI in nearly 50% of patients. Acute kidney injury and renal replacement therapy are independent predictors of worse outcome (hazard ratio [HR]: 3.704; 95% confidence interval [CI]: 1.867-7.350; P < .001; and HR: 2.848; CI: 1.301-6.325; P = .009). Chronic kidney disease was the strongest independent risk factor (odds ratio: 12.473; CI: 5.944-26.172; P < .001), whereas surgical intervention or contrast agents were not associated with AKI. CONCLUSIONS: Acute kidney injury in neurocritical care has a high incidence and is a crucial risk factor for mortality independently of the underlying neurocritical condition. Sepsis is the main cause of AKI in this setting. Therefore, careful prevention of infectious complications and considering CKD in treatment decisions may lower the incidence of AKI and hereby improve outcome in neurocritical care.

How to Prevent Renal Cachexia? A Clinical Randomized Pilot Study Testing Oral Supplemental Nutrition in Hemodialysis Patients With and Without Human Immunodeficiency Virus Infection.

OBJECTIVE: End-stage renal disease associates with catabolism and sarcopenia. Hypothetically, peroral supplemental nutrition over 6 months prevents catabolism in hemodialysis patients. DESIGN: Prospective randomized pilot study (ClinicalTrials.gov Identifier: NCT00687050). SUBJECTS: Twenty-three hemodialysis patients (15 males and 7 females) with or without human immunodeficiency virus (HIV) infection of 2 ambulatory hemodialysis centers. INTERVENTION: HIV-positive hemodialysis patients (n = 7, Group 1) were started on supplemental nutrition drinks (250 kcal/day), HIV-negative hemodialysis patients (n = 16, Group 2) were randomized to supplemental nutrition drinks (250 kcal/day) or received none. MAIN OUTCOME MEASURES: Body impedance analysis, anthropometric measures, magnetic resonance imaging results for mid-iliopsoas muscle cross-sectional area and laboratory parameters including albumin, cytokines at baseline, and at 6 months follow-up. RESULTS: Seven patients in Group 1 (mean age: 50.6 ± 9.6 years) and 16 patients in Group 2 (mean age: 54.0 ± 13.3 years) were recruited. Serum creatinine (Group 1: 6.4 ± 3.0 mg/dL; Group 2: 10.7 ± 2.5 mg/dL; P < .01), Body impedance analysis-derived phase angle alpha (Group 1: 5.1 ± 1.2; Group 2: 6.9 ± 1.6; P < .01), mid-arm circumference (Group 1: 26.1 ± 1.3 cm; Group 2: 29.6 ± 2.4 cm; P < .01) were less in Group 1 versus Group 2 patients at baseline suggesting that HIV-positive hemodialysis patients had a poorer nutritional status at baseline. At 6-month follow-up, mortality was higher in Group 1 patients (29%) than in Group 2 patients (6%). There was no significant treatment effect on nutritional status in survivors of Group 1 or in the supplemental nutrition arm of Group 2 when compared with baseline or to untreated controls. CONCLUSIONS: A new oral supplemental nutrition over 6 months had no treatment effect in surviving HIV-positive hemodialysis patients or in maintenance hemodialysis patients without HIV infection. The limitations of this study were small study size and unexpected high mortality among HIV-positive hemodialysis patients.

Direct acute tubular damage contributes to Shigatoxin-mediated kidney failure.

The pathogenesis and therapy of Shigatoxin 2 (Stx2)-mediated kidney failure remain controversial. Our aim was to test whether, during an infection with Stx2-producing E. coli (STEC), Stx2 exerts direct effects on renal tubular epithelium and thereby possibly contributes to acute renal failure. Mice represent a suitable model because they, like humans, express the Stx2-receptor Gb3 in the tubular epithelium but, in contrast to humans, not in glomerular endothelia, and are thus free of glomerular thrombotic microangiopathy (TMA). In wild-type mice, Stx2 caused acute tubular dysfunction with consequent electrolyte disturbance, which was most likely the cause of death. Tubule-specific depletion of Gb3 protected the mice from acute renal failure. In vitro, Stx2 induced secretion of proinflammatory cytokines and apoptosis in human tubular epithelial cells, thus implicating a direct effect of Stx2 on the tubular epithelium. To correlate these results to human disease, kidney biopsies and outcome were analysed in patients with Stx2-associated kidney failure (n = 11, aged 22-44 years). The majority of kidney biopsies showed different stages of an ongoing TMA; however, no glomerular complement activation could be demonstrated. All biopsies, including those without TMA, showed severe acute tubular damage. Due to these findings, patients were treated with supportive therapy without complement-inhibiting antibodies (eculizumab) or immunoadsorption. Despite the severity of the initial disease [creatinine 6.34 (1.31-17.60) mg/dl, lactate dehydrogenase 1944 (753-2792) U/l, platelets 33 (19-124)/nl and haemoglobin 6.2 (5.2-7.8) g/dl; median (range)], all patients were discharged after 33 (range 19-43) days with no neurological symptoms and no dialysis requirement [creatinine 1.39 (range 0.84-2.86) mg/dl]. The creatinine decreased further to 0.90 (range 0.66-1.27) mg/dl after 24 months. Based on these data, one may surmise that acute tubular damage represents a separate pathophysiological mechanism, importantly contributing to Stx2-mediated acute kidney failure. Specifically in young adults, an excellent outcome can be achieved by supportive therapy only.

Nephropathy in illicit drug abusers: a postmortem analysis.

BACKGROUND: Illicit drug abuse is an independent risk factor for chronic kidney disease, but the pathogenic consequences of long-term exposure to illicit drugs and contaminants under unsterile conditions remains unclear. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: All deceased persons (n 5 129) who underwent forensic autopsy because of suspected connection with illicit drug abuse between January 1, 2009, and April 30, 2011, in Frankfurt/Main, Germany. PREDICTOR: Clinical characteristics and patterns of drug abuse. OUTCOMES: Histopathologic alterations of the kidney. MEASUREMENTS: Hematoxylin and eosin, periodic acid-Schiff, Sirius, and Congo Red stainings and immunoglobulin A immunohistochemistry of all cases; additional histochemical stainings or immunohistochemistry and electron microscopy in selected cases. RESULTS: Individuals were mostly white (99.2%), were male (82.2%), and had intravenous drug use (IVDU) (81.4%). Median age at death was 39 years and duration of drug abuse was 17 years. The majority (79.1%) took various drugs in parallel as assessed by toxicologic analysis. Despite a young age, the deceased had a high burden of comorbid conditions, especially cardiovascular disease, liver cirrhosis, and infections. Evaluation of the kidneys demonstrated a broad spectrum of pathologic alterations predominated by arteriosclerotic and ischemic damage, mild interstitial inflammation, calcification of renal parenchyma, and interstitial fibrosis and tubular atrophy, with hypertensive-ischemic nephropathy as the most common cause of nephropathy. Interstitial inflammation (OR, 16.59; 95% CI, 3.91-70.39) and renal calcification (OR, 2.43; 95% CI, 1.03- 5.75) were associated with severe IVDU, whereas hypertensive and ischemic damage were associated with cocaine abuse (OR, 6.00; 95% CI, 1.27-28.44). Neither specific glomerular damage indicative for heroin and hepatitis C virus-related disease nor signs of analgesic nephropathy were found. LIMITATIONS: White population, lack of a comparable control group, incomplete clinical data, and absence of routine immunohistochemistry and electron microscopy. CONCLUSIONS: Illicit drug abuse is associated with a broad but unspecific spectrum of pathologic alterations of the kidneys. Cocaine abuse has a deleterious role in this setting by promoting hypertensive and ischemic damage.

Sympathoactivation and rho-kinase-dependent baroreflex function in experimental renovascular hypertension with reduced kidney mass.

BACKGROUND: Dysregulation of the autonomic nervous system is frequent in subjects with cardiovascular disease. The contribution of different forms of renovascular hypertension and the mechanisms contributing to autonomic dysfunction in hypertension are incompletely understood. Here, murine models of renovascular hypertension with preserved (2-kidneys-1 clip, 2K1C) and reduced (1-kidney-1 clip, 1K1C) kidney mass were studied with regard to autonomic nervous system regulation (sympathetic tone: power-spectral analysis of systolic blood pressure; parasympathetic tone: power-spectral analysis of heart rate) and baroreflex sensitivity of heart rate by spontaneous, concomitant changes of systolic blood pressure and pulse interval. Involvement of the renin-angiotensin system and the rho-kinase pathway were determined by application of inhibitors. RESULTS: C57BL6N mice (6 to 11) with reduced kidney mass (1K1C) or with preserved kidney mass (2K1C) developed a similar degree of hypertension. In comparison to control mice, both models presented with a significantly increased sympathetic tone and lower baroreflex sensitivity of heart rate. However, only 2K1C animals had a lower parasympathetic tone, whereas urinary norepinephrine excretion was reduced in the 1K1C model. Rho kinase inhibition given to a subset of 1K1C and 2K1C animals improved baroreflex sensitivity of heart rate selectively in the 1K1C model. Rho kinase inhibition had no additional effects on autonomic nervous system in either model of renovascular hypertension and did not change the blood pressure. Blockade of AT1 receptors (in 2K1C animals) normalized the sympathetic tone, decreased resting heart rate, improved baroreflex sensitivity of heart rate and parasympathetic tone. CONCLUSIONS: Regardless of residual renal mass, blood pressure and sympathetic tone are increased, whereas baroreflex sensitivity is depressed in murine models of renovascular hypertension. Reduced norepinephrine excretion and/or degradation might contribute to sympathoactivation in renovascular hypertension with reduced renal mass (1K1C). Overall, the study helps to direct research to optimize medical therapy of hypertension.

Durability of protective antibody titres is not enhanced by a two-dose schedule of an ASO3-adjuvanted pandemic H1N1 influenza vaccine in adult HIV-1-infected patients.

The immune response after influenza vaccination is impaired in HIV-infected individuals and can be enhanced by a second dose. The durability of the antibody protection and its clinical benefit is not known. We investigated clinical symptoms and antibody titres against H1N1 influenza A following no dose, 1 dose, or 2 doses of an ASO3-adjuvanted H1N1 vaccine in HIV-infected patients. Seroprotection was found in 7.9%, 52.2%, and 57.3% of patients who received no dose, 1 dose, and 2 doses of the vaccine, respectively (p-value for group comparison < 0.001), after a median of 8.2 ± 1.6 months. Clinical symptoms suggestive of an influenza-like illness were slightly more frequently reported in the unvaccinated group. Vaccinated HIV-infected patients were more likely to be seroprotected at follow-up, but there was no difference comparing those who had received 1 or 2 doses of the vaccine.

Immune response after a single dose of the 2010/11 trivalent, seasonal influenza vaccine in HIV-1-infected patients and healthy controls.

BACKGROUND: Immune response rates following influenza vaccination are often lower in HIV-infected individuals. Low vitamin D levels were correlated with weak immune response in cancer patients and are known to be lower in HIV-infected patients. METHODS: Diagnostic study to determine immune response against the H1N1v component after a single, intramuscular dose of the 2010/11 seasonal, trivalent influenza vaccine (TIV) in adult HIV-infected and healthy controls scheduled for influenza vaccination (ClinicalTrials.gov Identifier: NCT01017172). Influenza A/H1N1 antibody titers (AB) were determined before and 21 days after vaccination by hemagglutination inhibition assay. RESULTS: Immune response was not different between HIV-infected patients (n = 36) and healthy controls (n = 42) who were previously naïve to the H1N1v component of the TIV. Comparing HIV-infected patients (n = 55) and healthy controls (n = 63) who had received 1 or 2 doses of an AS03 adjuvanted H1N1 vaccine in the previous winter season (2009/10), seroconversion rate and the geometric mean AB titer after TIV of the HIV-infected patients were more than twice as high compared to healthy controls. This difference was mainly driven by the 2-dose schedule for HIV patients in 2009/10. Vitamin D levels were lower in HIV patients but did not correlate with immune response. CONCLUSION: HIV-infected patients who had received 1 or 2 doses of an adjuvanted H1N1 vaccine in the previous year (2009/10) had a significant higher seroconversion rate following TIV as compared to healthy controls, indicating a stronger memory cell response due to the 2-dose schedule.

Promoting Healthy Aging Using a Robot Support System and Emotion Recognition.

The aging population poses challenges such as loneliness, decreased mobility, and medical conditions. To tackle these issues, a proposed robot platform offers personalized well-being behavior change suggestions. Developed through a user-centered process involving surveys and focus groups, and tested with a first prototype, the system is ideal for individuals with "special social needs". Technical results indicate that emotion recognition is valuable, with attention and valence being key metrics, but user acceptance and quality of facial/speech analysis for elderly users remain challenges.

Renal AA-amyloidosis in intravenous drug users--a role for HIV-infection?

BACKGROUND: Chronic renal disease is a serious complication of long-term intravenous drug use (IVDU). Recent reports have postulated a changing pattern of underlying nephropathy over the last decades. METHODS: Retrospective investigation including all patients with prior or present IVDU that underwent renal biopsy because of chronic kidney disease between 01.04.2002 and 31.03.2012 in the city of Frankfurt/Main, Germany. RESULTS: Twenty four patients with IVDU underwent renal biopsy because of progressive chronic kidney disease or proteinuria. Renal AA-amyloidosis was the predominant cause of renal failure in 50% of patients. Membranoproliferative glomerulonephritis (GN) was the second most common cause found in 21%. Patients with AA-amyloidosis were more likely to be HIV infected (67 vs.17%; p=0.036) and tended to have a higher rate of repeated systemic infections (92 vs. 50%; p=0.069). Patients with AA-amyloidosis presented with progressive renal disease and nephrotic-range proteinuria but most patients had no peripheral edema or systemic hypertension. Development of proteinuria preceded the decline of GFR for approximately 1-2 years. CONCLUSIONS: AA-amyloidosis was the predominant cause of progressive renal disease in the last 10 years in patients with IVDU. The highest rate of AA-amyloidosis observed was seen in HIV infected patients with IVDU. We speculate that chronic HIV-infection as well as the associated immunosuppression might promote development of AA-amyloidosis by increasing frequency and duration of infections acquired by IVDU.

Development and Evaluation of the Taxonomy of Trauma Leadership Skills-Shortened for Observation and Reflection in Training: A Practical Tool for Observing and Reflecting on Trauma Leadership Performance.

INTRODUCTION: Trauma leadership skills are increasingly being addressed in trauma courses, but few resources are available to systematically observe and debrief trainees' performances. The authors therefore translated their previously developed, extensive Taxonomy of Trauma Leadership Skills (TTLS) into a practical observation tool that is tailored to the vocabulary of clinician instructors and their workflow and workload during simulation-based training. METHODS: In 2016 to 2018, the TTLS was subjected to practical evaluation in an iterative process of 2 stages. In the first stage, testing panels of trauma specialists observed excerpts from videotaped simulations and indicated from the list of elements which behaviors they felt were being shown. Any ambiguities or redundancy were addressed by rephrasing or combining elements. In the second stage, iterations were used in actual scenario training to observe and debrief trainees' performances. The instructors' recommendations resulted in further improvements of clarity, ease of use, and usefulness, until no new suggestions were raised. RESULTS: The resultant "TTLS-Shortened for Observation and Reflection in Training" was given a simpler structure and more concrete and self-explanatory benchmarks. It contains 6 skill categories for evaluation, each with 4 to 6 benchmark behaviors. CONCLUSIONS: The TTLS-Shortened for Observation and Reflection in Training is an important addition to other trauma assessment tools because of its specific focus on leadership skills. It helps set concrete performance expectations, simplify note taking, and target observations and debriefings. One central challenge was striking a balance between its conciseness and specificity. The authors reflected on how the decisions for the resultant structure ease and leverage the conduct of observations and performance debriefing.

FHIR Driven Self-Management Support System for Diabetes.

The number of people with diabetes is increasing in every European country and as with all chronic diseases, coping with diabetes is a long-term process. Self-Management and supporting behaviour change are aspects when dealing with diabetes. The POWER2DM (Funded by the EU Horizon 2020 research and innovation programme under grant agreement No 689444) system combines treatment planning and self-management activities by providing interventions to change a patient's lifestyle towards a healthier, diabetes-appropriate life. FHIR3 allows for data exchange.

Quantifying Concentration Polarization - Raman Microspectroscopy for In-Situ Measurement in a Flat Sheet Cross-flow Nanofiltration Membrane Unit.

In this work, the concentration polarization layer (CPL) of sulphate in a cross-flow membrane system was measured in-situ using Raman microspectroscopy (RM). The focus of this work is to introduce RM as a new tool for the study of mass transfer inside membrane channels in reverse osmosis (RO) and nanofiltration (NF) generally. Specifically, this work demonstrates how to use RM for locally resolved measurement of sulphate concentration in a cross-flow flat-sheet NF membrane flow cell with channel dimensions similar to commonly applied RO/NF spiral wound modules (channel height about 0.7 mm). Concentration polarization profiles of an aqueous magnesium sulphate solution of 10 gsulphate·L-1 were obtained at operating pressure of 10 bar and cross-flow velocities of 0.04 and 0.2 m·s-1. The ability of RM to provide accurate concentration profiles is discussed thoroughly. Optical effects due to refraction present one of the main challenges of the method by substantially affecting signal intensity and depth resolution. The concentration profiles obtained in this concept study are consistent with theory and show reduced CPL thickness and membrane wall concentration with increasing cross-flow velocity. The severity of CP was quantified to reach almost double the bulk concentration at the lower velocity.

Empowering Diabetes Patients with Interventions Based on Behaviour Change Techniques.

The number of people with diabetes is increasing in every European country and like all chronic diseases it cannot be cured. However, patient empowerment is an acknowledged strategy for improving the patients' health situation. This paper describes the Action Plan Engine developed as a tool for diabetes patients in the POWER2DM project. The Action Plan Engine offers a guided workflow based on treatment goals and activities. A periodic review evaluates how successful a patient has fulfilled these goals and activities. Part of the evaluation is detailed feedback, in particular about 170 interventions based on Behaviour Change Techniques in order to change a patient's lifestyle behaviour towards a healthier, diabetes-appropriate lifestyle. Additionally, the Action Plan Engine offers decision trees for coping with barriers regarding glucose monitoring, exercise, carbohydrate, insulin and stress.

Key role of renal biopsy in management of progressive chronic kidney disease in liver graft recipients.

AIMS: Chronic kidney disease (CKD) is a common complication after liver transplantation (LT). The etiology of CKD is broad and may only be assessed accurately by renal histology. The current study aimed to analyze the safety of renal biopsy in daily clinical practice as well as its usefulness regarding management of CKD after LT. METHODS: We performed a retrospective analysis of clinical data and renal biopsies obtained from patients with severe renal impairment (overt proteinuria, progressive deterioration of renal function) after LT with respect to safety, etiology of renal disease, and therapeutic consequences. RESULTS: Renal biopsies were obtained from 14 patients at median (minimum-maximum) 3 (0.2-12) years after LT. No major complications associated with renal biopsy were observed. Histomorphological alterations were varied (nephrosclerosis, n = 5; IgA-glomerulonephritis, n = 4; tenofovir-associated nephropathy, membranoproliferative glomerulonephritis type 1, membranous glomerulonephritis, amyloid A amyloidosis, and calcineurin inhibitor nephropathy, n = 1, respectively). The diagnosis of specific renal diseases other than calcineurin-inhibitor nephrotoxicity facilitated specific treaments and avoided unnecessary modification of immunosuppression in the majority of patients. CONCLUSIONS: Renal biopsy in patients with CKD after LT seems safe and may offer specific therapeutic options. Furthermore, unnecessary changes of immunosuppression can be avoided in a considerable number of patients.

Inactivation of extracellular superoxide dismutase contributes to the development of high-volume hypertension.

OBJECTIVES: Extracellular superoxide dismutase (ecSOD) lowers superoxide anions and maintains vascular nitric oxide level. We studied the function of ecSOD in high-volume hypertension induced by the 1-kidney-1-clip model in wild-type, ecSOD-/- mice, and endothelial nitric oxide synthase (eNOS)-/- mice. METHODS AND RESULTS: The 1-kidney-1-clip model resulted in impaired endothelium-dependent relaxation and hypertension and vascular oxidative stress in wild-type and ecSOD-/- mice. Recombinant ecSOD lowered the blood pressure and improved aortic nitric oxide bioavailability in wild-type and ecSOD-/- but not eNOS-/- mice. ecSOD had no effect on blood pressure in eNOS-/- or wild-type mice treated with a nitric oxide synthase inhibitor. The 1-kidney-1-clip model markedly induced ecSOD protein expression, whereas activity was increased by only 25%, suggesting a partial inactivation of ecSOD in high-volume hypertension. Incubation of aortic segments with peroxynitrite or hydrogen peroxide attenuated ecSOD activity, but peroxynitrite did not induce tyrosine nitration of ecSOD, suggesting oxidative inactivation of the enzyme. Administration of polyethyleneglycol-catalase for 3 days selectively lowered the blood pressure in ecSOD+/+ but not ecSOD-/- mice and improved nitric oxide bioavailability. In contrast, acute application of catalase had no effect. CONCLUSIONS: Nitric oxide mediates the vascular effects of ecSOD. Vascular dysfunction in 1-kidney-1-clip model hypertension is partially a consequence of inactivation of ecSOD by reactive oxygen species.

Challenges for conducting and teaching handovers as collaborative conversations: an interview study at teaching ICUs.

INTRODUCTION: Whereas medical shift handovers are increasingly recognized to fulfil important functions beyond information transfer, studies suggest that shift handovers continue to be variably used for reflection, learning or discussion. Little is known of the dynamics of incorporating such functions into ICU shift handovers, resulting in a challenge for the design of educational programs whose underlying philosophies align with the specific requirements of the ICU. METHODS: Intensivists, residents and fellows (n = 21) from three ICUs were interviewed to determine perceptions of handover functionality and the boundaries to what must or can be achieved in handover conversations. Interviews were analyzed to isolate training requirements and factors that challenge interactions. RESULTS: The analysis revealed that ICU physicians value three functions for shift handovers: information transfer, enhancing shared understanding and decision-making, and learning. The functions towards which physicians are oriented were found to be affected by situational characteristics of cases, individuals, teams, and the unit workflow. Whereas some factors are helpful cues for determining communication needs, others raise dilemmas and misaligned expectations with regards to what can be achieved in the handover. DISCUSSION: Our findings add to the growing case for the education of handovers in complex settings to involve more than information transfers. As residents gain experience, training should be gradually shifted towards more fluid and adaptable approaches to the handover and residents' ability to engage in joint reflections and discussions. Challenges for engaging in such interactions need to be alleviated, in order to allow the redefinition of handovers as potential sources of safety and learning, rather than error.

[Therapy of Intradialytic Chronic Metabolic Acidosis in Germany - Is it According to Latest Evidence?] / Therapie der chronischen metabolischen Azidose bei Hämodialysepatienten in Deutschland ­ Sind wir auf dem neuesten Stand?

Background Chronic metabolic acidosis is a frequent comorbidity in chronic kidney disease, especially in patients undergoing dialysis. Recent study data suggest that treatment of acidosis during dialysis with bicarbonate may result in increased levels of serum bicarbonate, which is associated with increased mortality. Methods We aimed to evaluate the current management of chronic metabolic acidosis in Germany: have recent study results been transferred into daily routine and are nephrologists aware of these new study data? Therefore, we did a survey with 17 questions among 2096 German nephrologists. 280 valid responses were returned and analysed with descriptive statistics. Results Blood gas analysis was done weekly (27 % of respondents), monthly (20 %), every 3 months (19 %), less frequently (5 %) or not routinely (3 %). It was done by most respondents prior to the dialysis session (83 %) and by some (20 %) also afterwards or during the session (3 %). 20 % did blood gas analysis "as required".Oral bicarbonate was discontinued at start of dialysis by 66 % of nephrologists; 22 % of these do generally not use it and 44 % usually discontinue it but might continue if required. 34 % of responding nephrologists continue oral bicarbonate when starting dialysis but might adjust dose. Discussion Recent study data might have to be better promoted among nephrologists. Although KDIGO guidelines recommend at least monthly blood gas analysis, about one quarter of nephrologists stated to do it less frequently. Furthermore, blood gas analysis was rarely done after dialysis treatment and thus, important information about success or failure of bicarbonate correction was not obtained. If alkalotic episodes after dialysis treatment would be detected this way, regular oral bicarbonate might be an option for correction of metabolic acidosis.

Xanthine oxidase inhibitor tungsten prevents the development of atherosclerosis in ApoE knockout mice fed a Western-type diet.

Hyperlipidemia enhances xanthine oxidase (XO) activity. XO is an important source of reactive oxygen species (ROS). Since ROS are thought to promote atherosclerosis, we hypothesized that XO is involved in the development of atherosclerosis. ApoE(-/-) mice were fed a Western-type (WD) or control diet. In subgroups, tungsten (700 mg/L) was administered to inhibit XO. XO is a secreted enzyme which is formed in the liver as xanthine dehydrogenase (XDH) and binds to the vascular endothelium. High expression of XDH was found in the liver and WD increased liver XDH mRNA and XDH protein expression. WD induced the conversion of XDH to the radical-forming XO. Moreover, WD increased the hepatic expression of CD40, demonstrating activation of hepatic cells. Aortic tissue of ApoE(-/-) mice fed a WD for 6 months exhibited marked atherosclerosis, attenuated endothelium-dependent relaxation to acetylcholine, increased vascular oxidative stress, and mRNA expression of the chemokine KC. Tungsten treatment had no effect on plasma lipids but lowered the plasma XO activity. In animals fed a control diet, tungsten had no effect on radical formation, endothelial function, or atherosclerosis development. In mice fed a WD, however tungsten attenuated the vascular superoxide anion formation, prevented endothelial dysfunction, and attenuated KC mRNA expression. Most importantly, tungsten treatment largely prevented the development of atherosclerosis in the aorta of ApoE(-/-) mice on WD. Therefore, tungsten, potentially via the inhibition of XO, prevents the development of endothelial dysfunction and atherosclerosis in ApoE(-/-) mice on WD.

Extracellular superoxide dismutase is a major determinant of nitric oxide bioavailability: in vivo and ex vivo evidence from ecSOD-deficient mice.

The bioavailability of nitric oxide (NO) within the vascular wall is limited by superoxide anions (O2.-). The relevance of extracellular superoxide dismutase (ecSOD) for the detoxification of vascular O2.- is unknown. We determined the involvement of ecSOD in the control of blood pressure and endothelium-dependent responses in angiotensin II-induced hypertension and renovascular hypertension induced by the two-kidney, one-clip model in wild-type mice and mice lacking the ecSOD gene. Blood pressure was identical in sham-operated ecSOD+/+ and ecSOD-/- mice. After 6 days of angiotensin II-treatment and 2 and 4 weeks after renal artery clipping, blood pressure was significantly higher in ecSOD-/- than ecSOD+/+ mice. Recombinant ecSOD selectively decreased blood pressure in hypertensive ecSOD-/- mice, whereas ecSOD had no effect in normotensive and hypertensive ecSOD+/+ mice. Compared with sham-operated ecSOD+/+ mice, sham-operated ecSOD-/- mice exhibited attenuated acetylcholine-induced relaxations. These responses were further depressed in vessels from clipped animals. Vascular O2.-, as measured by lucigenin chemiluminescence, was higher in ecSOD-/- compared with ecSOD+/+ mice and was increased by clipping. The antioxidant tiron normalized relaxations in vessels from sham-operated and clipped ecSOD-/-, as well as from clipped ecSOD+/+ mice. In contrast, in vivo application of ecSOD selectively enhanced endothelium-dependent relaxation in vessels from ecSOD-/- mice. These data reveal that endogenous ecSOD is a major antagonistic principle to vascular O2.-, controlling blood pressure and vascular function in angiotensin II-dependent models of hypertension. ecSOD is expressed in such an abundance that even in situations of high oxidative stress no relative lack of enzyme activity occurs.