Cellular prion proteins in human platelets show a phenotype different to those in brain tissues.

Prion diseases are characterized by high accumulation of infectious prion proteins (PrP(Sc)) in brains. PrP(Sc) are propagated by the conversion of host-encoded cellular prion proteins (PrP(C)) which are essential for developing the disease but are heterogeneously expressed in brains. The disease can be transmitted to humans and animals through blood and blood products, however, little attention has been given to molecular characterization of PrP(C) in blood cells. In this presented study, we characterized phenotypically PrP(C) of platelets (plt) and characterized the proteins regarding their glycobanding profiles by quantitative immunoblotting using a panel of monoclonal antibodies. The glycosylation patterns of plt and brain PrP(C) were compared using the ratios of di-, mono-, and non-glycosylated prions. The detergent solubility of plt and brain PrP(C) was also analyzed. The distinct banding patterns and detergent solubility of plt PrP(C) differed clearly from the glycosylation profiles and solubility characteristics of brain PrP(C). Plt PrP(C) exhibited single or only few prion protein types, whereas brain PrP(C) showed more extensive banding patterns and lower detergent solubility. Plt PrP(C) are post-translational modified differently from PrP(C) in brain. These findings suggest other or less physiological functions of plt PrP(C) than in brain.

Serious Games in Surgical Medical Education: A Virtual Emergency Department as a Tool for Teaching Clinical Reasoning to Medical Students.

BACKGROUND: Serious games enable the simulation of daily working practices and constitute a potential tool for teaching both declarative and procedural knowledge. The availability of educational serious games offering a high-fidelity, three-dimensional environment in combination with profound medical background is limited, and most published studies have assessed student satisfaction rather than learning outcome as a function of game use. OBJECTIVE: This study aimed to test the effect of a serious game simulating an emergency department ("EMERGE") on students' declarative and procedural knowledge, as well as their satisfaction with the serious game. METHODS: This nonrandomized trial was performed at the Department of General, Visceral and Cancer Surgery at University Hospital Cologne, Germany. A total of 140 medical students in the clinical part of their training (5th to 12th semester) self-selected to participate in this experimental study. Declarative knowledge (measured with 20 multiple choice questions) and procedural knowledge (measured with written questions derived from an Objective Structured Clinical Examination station) were assessed before and after working with EMERGE. Students' impression of the effectiveness and applicability of EMERGE were measured on a 6-point Likert scale. RESULTS: A pretest-posttest comparison yielded a significant increase in declarative knowledge. The percentage of correct answers to multiple choice questions increased from before (mean 60.4, SD 16.6) to after (mean 76.0, SD 11.6) playing EMERGE (P<.001). The effect on declarative knowledge was larger in students in lower semesters than in students in higher semesters (P<.001). Additionally, students' overall impression of EMERGE was positive. CONCLUSIONS: Students self-selecting to use a serious game in addition to formal teaching gain declarative and procedural knowledge.

Endothelial progenitor cells in kidney transplant recipients.

BACKGROUND: Lower concentrations of endothelial progenitor cells (EPCs) may be associated with increased cardiovascular risk. EPC counts and their correlates have not yet been studied in kidney transplant recipients (KTR). METHODS: We cross-sectionally studied EPC counts in 105 middle-aged KTR (mean estimated glomerular filtration rate 45.2 ml/min/1.73 m; range: 5.4 to 117.5). Using univariate and multivariate linear regression assuming a gamma distribution of the outcome, we examined the associations between counts of cultured EPCs and traditional cardiovascular disease risk factors (hypertension, diabetes, hyperlipidemia, smoking), kidney function, and immunosuppressive agents, amongst others. RESULTS: The median count of cultured EPCs was 34 cells per high-power field (interquartile range: 19 to 64), comparable to healthy individuals. From multivariate analyses, we found independent inverse associations between counts of cultured EPCs and body mass index, mean arterial pressure, and history of cardiovascular disease. Statin use was associated with greater EPC counts, whereas patients receiving azathioprine or angiotensin II receptor treatment had lower EPC counts (all P<0.01). CONCLUSIONS: This study suggests negative associations in KTR between EPC counts and body mass index, and blood pressure, whereas statin use was associated with greater EPC counts. These findings raise the hypothesis whether EPCs are responsible, at least in part, for the well established associations between these factors and cardiovascular outcomes in KTR.

Prevalence of uncontrolled hypertension in patients with Fabry disease.

BACKGROUND: Fabry disease is a rare X-linked disease arising from deficiency of alpha-galactosidase A. It results in early death related to renal, cardiac, and cerebrovascular disease, which are also important outcomes in patients with elevated blood pressure (BP). The prevalence of uncontrolled hypertension, as well as the effect of enzyme replacement therapy on BP, in patients with Fabry disease is unknown. METHODS: We examined uncontrolled hypertension (systolic BP [SBP] >or=130 mm Hg or diastolic BP [DBP] >or=80 mm Hg) among 391 patients with Fabry disease who were participating in the Fabry Outcome Survey (FOS). RESULTS: Uncontrolled hypertension was present in 57% of men and 47% of women. In patients with chronic kidney disease (CKD) stage 1 (n100), median SBP was 120 mm Hg and median DBP was 74 mm Hg. In patients with CKD stage 2 (n172), median SBP was 125 mm Hg and median DBP was 75 mm Hg. In patients with CKD stage 3 (n63), median SBP was 130 mm Hg and median DBP was 75 mm Hg. There was a significant decrease in both SBP and DBP during a 2-year course of enzyme replacement therapy. CONCLUSIONS: This study revealed a high prevalence of uncontrolled hypertension among patients with Fabry disease. Thus there is a need to improve BP control and renoprotection in patients with Fabry disease.

Oscillatory responses to reward processing in borderline personality disorder.

OBJECTIVES: Previous electrophysiological studies have confirmed impaired reward processing in patients with BPD. However, it is not clear which aspects of reward processing are affected and which brain regions are involved. The present study investigated both evoked and induced event-related oscillations (EROs) to feedback events (thought to represent different aspects of feedback processing), and used source localization (sLORETA) to assess activity in two areas known to contribute to reward processing, the dorsomedial prefrontal/anterior cingulate cortex (dmPFC/ACC) and the orbitofrontal cortex (OFC). METHODS: Eighteen patients with BPD and 22 healthy controls performed a gambling task, while 64-channel electroencephalographic activity was recorded. Evoked and induced theta and high-beta band EROs as well as activity in the two regions of interest were investigated depending on the valence and magnitude of feedback events. RESULTS: Theta-band responses to negative feedback were reduced in BPD, an effect that involved only evoked responses and the dmPFC/ ACC region, and was associated with trait impulsivity in patients. sLORETA analyses revealed disturbed evoked responses depending on feedback magnitude in the theta (OFC) and high-beta (dmPFC/ACC and OFC) frequency range. CONCLUSIONS: The results indicate multiple dysfunctions of feedback processing in patients with BPD, implicating several distinct subsets of reward-processing mechanisms.

Interfering parameters in the determination of urinary globotriaosylceramide (Gb3) in patients with chronic kidney disease.

INTRODUCTION: Globotriaosylceramide (Gb3, CD77) represents a pivotal part of the cell membrane. Measuring the urinary Gb3 content can be used to screen patients with chronic kidney disease (CKD) for Fabry disease, a disorder caused by hampered Gb3 degradation. However, little is known about factors influencing urinary Gb3 excretion other than Fabry disease. The aim of the present study was to identify routine diagnostic parameters as predictors of urinary Gb3 excretion in patients with CKD. METHODS: Our study included 609 subjects with CKD stage I-V. We analyzed the influence of age, gender, renal function, urinary cell content and chemical characteristics on urinary Gb3 concentrations (total Gb3, Gb3-24 isoform, and Gb3-24:18 isoform ratio), determined by direct electrospray ionization mass spectrometry. RESULTS: In 609 subjects the median total urinary Gb3 was 233 ng/mg and the Gb3-24:18 isoform ratio was 1.2. Twenty-one patients, none of whom had Fabry disease, had a Gb3-24:18 isoform ratio ≥2.3. Females excreted a higher total amount of Gb3, but the Gb3-24:18 isoform ratio was comparable to males. Renal function and age had no influence on total Gb3, Gb3 isoforms or the ratio. Only a distinct load of bacteria and leukocytes was associated with an increased Gb3 excretion. Urinary leukocytes, erythrocytes, bacteria, or protein content did not affect the Gb3-24:18 isoform ratio. CONCLUSION: The Gb3-24:18 isoform ratio is unaffected by several potential influencing variables and may thus be applied for screening for Fabry disease in unselected cohorts of patients presenting with CKD.

Refractory Wegener's granulomatosis responds to tumor necrosis factor blockade.

Wegener's granulomatosis is a systemic necrotising vasculitis of small vessels that leads to severe impairment of affected organ systems. Conventional treatment is based on immunosuppression with a combination of steroids, cyclophosphamide, azathioprine or methotrexate over a prolonged time course. Early recurrence or disease refractory to therapy often results in a fatal outcome. As in other inflammatory disorders, tumor necrosis factor (TNF) plays an early and crucial role in progression of disease activity. We report on a patient with severe orbital Wegener's granulomatosis who developed acute renal failure despite intense conventional immunosuppression with cyclophosphamide and steroids. To stop vasculitic activity, by disrupting the autoimmune inflammatory cascade, a TNF-blocking antibody (Infliximab) was administered six times in a six-month period at 3 mg/kg body weight. Conventional immunosuppressive therapy with steroids and cyclophosphamide was continued, the latter being changed to azathioprine after three months. The first infusion of TNF antibody induced improvement of renal function, which continued throughout the course of therapy. The modification of diet in renal disease-glomerular filtration rate (MDRD-GFR) increased from 15.3 ml/min/1.73 m2 before the start of TNF-blockade to 55.5 ml/min/1.73 m2 after six months of therapy. Serum creatinine levels, proteinuria and cANCA titer decreased concomitantly. Clinical remission of Wegener's granulomatosis was induced without any major adverse events. A slight flare of orbital inflammation was successfully treated with an increased dose of azathioprine. Thus, in this case of refractory Wegener's granulomatosis TNF-blockade by monoclonal chimeric TNF-antibody (Infliximab) served as an effective tool to rescue kidney function and induce clinical remission.

Anderson-Fabry disease: a case-finding study among male kidney transplant recipients in Austria.

The diagnosis of Anderson-Fabry disease is often delayed or even missed. As severe renal manifestations are a hallmark of alfa-galactosidase A (AGAL) deficiency, we tested the hypothesis that Anderson-Fabry disease is under-recognized among male kidney transplant recipients. This nation-wide study in Austria enrolled 1306 patients (ca 65% of all kidney transplanted males) from 30 kidney centers. AGAL activity was determined from filter paper dried blood spots by a fluorescence assay. A positive screening test was defined by an AGAL activity below 1.5 nmol/h/ml. In patients with a positive blood spot-screening test, AGAL activity was re-examined in peripheral blood leukocytes. Genetic testing for mutations in the GLA gene was performed by sequencing to confirm the diagnosis of Anderson-Fabry disease. Two previously not recognized cases with Anderson-Fabry disease were identified. Our study is the first showing that a diagnosis of Anderson-Fabry disease can be missed even in patients who undergo kidney transplantation. Case-finding strategies may be considered a useful tool for diagnosis of this rare disease that may be somewhat more prevalent among kidney transplant recipients compared with dialysis populations.

Anemia is a new complication in Fabry disease: data from the Fabry Outcome Survey.

BACKGROUND: The prevalence and causes of anemia among patients with Fabry disease are unknown. METHODS: In a cross-sectional study we examined hemoglobin concentrations of patients with Fabry disease using a large international database, the Fabry Outcome Survey (FOS), and analyzed the association of renal function, heart failure, gastrointestinal symptoms, and inflammation, with anemia (hemoglobin <12 g/dL in females and <13 g/dL in males). RESULTS: Anemia was present in 34% of 345 patients with Fabry disease. Median hemoglobin in 158 females was 12.9 g/dL and the median hemoglobin of 187 male patients was 13.2 g/dL. The prevalence of anemia among females was 20%, and among males 47%. Among patients with normal renal function [estimated glomerular filtration rate (GFR) >90 mL/min/1.73 m(2)] and anemia, heart failure [New York Heart Association (NYHA) class II to IV] and/or elevated C-reactive protein (CRP) levels were documented in 82% of patients. Up to 67% of patients with decreased estimated GFR presented with anemia. There was also a trend for lower hemoglobin levels among patients with signs of inflammation (defined by an elevated CRP level). We observed no association of the presence of gastrointestinal symptoms with anemia. Analyses in 53 patients receiving enzyme replacement therapy for up to 2 years, suggest no effect on anemia. CONCLUSION: The results of this study point to a high prevalence of anemia among patients with Fabry disease that is in most instances related to impaired renal function, heart failure, and inflammation. This finding may be of clinical relevance, because anemia is a major risk factor for patients with kidney disease, heart failure, or stroke, which are important manifestations of Fabry disease.