Medical students' knowledge and attitudes regarding vaccination against measles, influenza and HPV. An international multicenter study.

INTRODUCTION: Inaccurate information leads to increased scepticism concerning vaccinations among health care workers. Therefore, a proper education of medical students on vaccination is important. METHODS: During summer term 2015, we performed a paper-based survey to identify the knowledge and attitudes of medical students on vaccinations against measles, influenza and HPV in seven medical schools in Germany, Austria and Switzerland. RESULTS: Altogether, 3,652 questionnaires were analyzed. Knowledge of country-specific public recommendations increased significantly with the number of semesters of medical studies. Concerning the knowledge about vaccinations against measles, influenza and HPV, one third of the answers were given correctly. Again, a strong correlation between the knowledge and the semester of medical studies could be observed. The attitudes concerning vaccinations in general and especially for HCWs were highly positive. CONCLUSIONS: This study provides some important arguments for the development of a comprehensive vaccination education for medical students.

Cardiac thrombus with risk of fulminant pulmonary embolism in paediatric antiphospholipid syndrome.

Antiphospholipid Syndrome (APS) describes a systemic disease caused by autoantibodies to membrane components. Involving coagulation pathways, complement factors and immune cells, it results in thrombosis in any blood vessel. Its clinical presentation varies considerably depending upon the organ affected. Paediatric data on APS remain sparse. Most case reports focus on catastrophic APS with multiple small-vessel occlusions and a life-threatening course. Here, we report on a 15-year-old patient with deep vein thrombosis and a right ventricular tumour posing the risk of a fulminant pulmonary embolism. The tumour was surgically removed. Histology revealed it to be a thrombus. The patient fully recovered and is currently treated with long term anticoagulation.

Vaccination: Developing and implementing a competency-based-curriculum at the Medical Faculty of LMU Munich.

BACKGROUND: In Germany medical students should gain proficiency and specific skills in the vaccination field. Especially important is the efficient communication of scientific results about vaccinations to the community, in order to give professional counseling with a complete overview about therapeutic options. AIM OF THE PROJECT: The aim of this project is to set up a vaccination-related curriculum in the Medical Faculty at the Ludwig-Maximilians-University in Munich. The structure of the curriculum is based on the National catalogue for competency-based learning objectives in the field of vaccination (Nationaler Kompetenzbasierter Lernzielekatalog Medizin NKLM). Through this curriculum, the students will not only acquire the classical educational skills concerning vaccination in theory and practice, but they will also learn how to become independent in the decision-making process and counseling. Moreover, the students will become aware of consequences of action related to this specific topic. METHODS: According to defined guidelines, an analysis was performed on courses, which are currently offered by the university. A separate analysis of the NKLM was carried out. Both analyses identified the active courses related to the topic of vaccination as well as the NKLM learning objectives. The match between the topics taught in current courses and the NKLM learning objectives identified gaps concerning the teaching of specific content. Courses were modified in order to implement the missing NKLM learning objectives. RESULTS: These analyses identified 24 vaccination-related courses, which are currently taught at the University. Meanwhile, 35 learning objectives on vaccination were identified in the NKLM catalogue. Four of which were identified as not yet part of the teaching program. In summary, this interdisciplinary work enabled the development of a new vaccination-related curriculum, including 35 learning objectives, which are now implemented in regular teaching courses by the Medical Faculty. CONCLUSIONS: This project successfully describes a method to develop and implement a competency-based teaching program on the topic of vaccination. Importantly, the process presented here can serve as a guide to develop and implement similar teaching programs on other subjects and Universities.

[Prevention in the elderly: position paper on pneumococcal vaccinations. Results of an expert workshop on 15 November 2013 in Cologne, Germany]. / Prävention im Alter: Stellungnahme zur Pneumokokkenimpfung. Ergebnisse eines Expertenworkshops am 15.11.2013 in Köln.

Infections due to pneumococci especially in the elderly are vastly underestimated, e.g., because non-invasive infections such as pneumonia may appear with only few symptoms. Sequential vaccination with the pneumococcal conjugate vaccine PCV13, followed by the 23-valent polysaccharide vaccine, is considered as the best preventive measure for individual protection, even though clinical study data demonstrating the efficacy of this sequence are not yet available. Increase of "awareness" by use of computer-based reminder functions may result in a significant improvement of vaccination compliance.

Gelfoam for closure of large percutaneous transhepatic and transsplenic puncture tracts in pediatric patients.

PURPOSE: Evaluation of the efficacy and safety of Gelfoam for the closure of transhepatic or transsplenic parenchymal puncture tracts with large-bore sheaths in pediatric patients. MATERIALS AND METHODS: Between January 2012 and May 2013, 8 percutaneous transhepatic accesses and 3 percutaneous transsplenic accesses were closed using percutaneous Gelfoam in pediatric patients. The primary study endpoints to determine treatment efficacy and safety were patient survival, technical success defined as successful closure of the puncture tract without signs of bleeding, and complication rates. The secondary study endpoints were the occurrence of local and systemic inflammation. RESULTS: Overall survival was 100 % with a median follow-up of 256 days. The procedure was technically successful in 10 of 11 procedures. One patient suffered from bleeding, which was successfully managed by a single blood transfusion. No re-bleeding was detected during follow-up and no surgical interventions were necessary. No signs of local or systemic infections related to the Gelfoam application occurred. CONCLUSION: Percutaneous Gelfoam application is an effective and safe technique for the closure of transhepatic or transsplenic accesses in pediatric patients. KEY POINTS: Interventional closure of large transhepatic and transsplenic parenchymal accesses in children after interventional treatment is recommended to avoid bleeding. Gelfoam application does not cause artifacts in magnetic resonance imaging and does not increase the risk of local or systemic inflammation in comparison to permanent embolic agents. Thus, especially children under immunosuppressive therapy can benefit from the application of Gelfoam.

HIV infection changes glomerular podocyte cytoskeletal composition and results in distinct cellular mechanical properties.

In addition to forming the selective filtration barrier for the renal glomerulus, podocytes maintain glomerular capillary architecture by opposing distending hemodynamic forces. To understand the relationship of cytoskeletal properties and the mechanical characteristics of podocytes, we studied filamin expression and distribution and measured cell membrane deformability in conditionally immortalized wild-type (WT) mouse podocytes, and in podocytes derived from a mouse model of HIV-associated nephropathy (HIVAN). In the WT cells, filamin and F-actin were localized at the periphery and in prominent stress fibers. In the HIVAN cells, filamin expression was reduced, and stress fibers were sparse. In a microaspiration assay, HIVAN cells ruptured under minimal negative pressure. Atomic force microscopy demonstrated that the WT cells had a stiffness of 17 kPa, whereas the value for the HIVAN cells was 4 kPa. These results demonstrate that the mechanical properties of WT and HIVAN podocytes are markedly different in a manner that is consistent with differences in the composition and arrangement of their cytoskeletons. The mechanical properties of the WT podocytes suggest that these cells can better maintain capillary integrity than the HIVAN podocytes and implicate pathological assembly of the cytoskeleton as a mechanism of HIVAN.

The NHE1 Na+/H+ exchanger regulates cell survival by activating and targeting ezrin to specific plasma membrane domains.

NHE1 is a ubiquitously expressed Na+/H+ exchanger, which is important for vital cell functions. Using in vivo models of kidney podocyte injury and renal tubular epithelial cell (RTC) culture systems, we previously demonstrated that NHE1 defends against apoptosis by a mechanism involving ezrin binding to the NHE1 cytoplasmic domain. We now extend the NHE1 role to diabetic mouse models and refine the mechanism of NHE1-dependent ezrin activation. Streptozotocin induced diabetes resulted in greater azotemia, albuminuria and tubulointerstitial pathology in NHE1-deficient swe/swe compared to wild-type control mice. Increased RTC apoptosis was noted in swe/swe mice, suggesting that loss of NHE1 function leads to tubular atrophy, which predicts kidney disease progression. In vitro, proximal RTC derived from swe/swe mice also underwent increased apoptosis in response to staurosporine or a hypertonic environment. Activated ezrin normally resides in the apical domain of the proximal RTC, while NHE1 is a basolateral protein. After NHE1 activation by intracellular acidification or extracellular hypertonicity, confocal immunofluorescence microscopy in polarized LLC-PK1 cells demonstrated transient ezrin localization to lateral membrane domains, where it is positioned to interact with NHE1. We conclude that cell stresses promote NHE1-ezrin interaction, which activate cell survival pathways to prevent apoptosis in diabetic and non-diabetic kidney diseases.

Apoptosis and JNK activation are differentially regulated by Fas expression level in renal tubular epithelial cells.

BACKGROUND: In chronic renal disease, renal tubular epithelial cell (RTC) Fas expression is up-regulated, leading to apoptotic RTC deletion and tubular atrophy. In vitro, cytokine- or hypoxia-induced up-regulation of Fas expression is associated with RTC apoptosis. In contrast, constitutively expressed, low level RTC Fas does not mediate apoptosis, suggesting that Fas may be coupled to expression level-dependent RTC signaling pathways. Fas is known to signal through JNK in many systems, but the requirement of JNK activation for apoptosis remains controversial. METHODS: To determine if RTC Fas regulates JNK activity and apoptosis, human RTC were transfected with graded concentrations of a eukaryotic expression vector for murine Fas. Apoptosis was measured by annexin V, TUNEL and PARP cleavage assays. JNK activity was determined by immune complex kinase assay and/or immunoblots with phospho-specific JNK antibodies, in the presence or absence of co-expressed dominant negative JNK constructs. RESULTS: Fas antibody stimulation of RTC with high Fas expression levels (to model RTC phenotype in renal disease) caused a tenfold increase in apoptosis, while RTC with low level Fas expression (to model normal RTC phenotype) were apoptosis-resistant. Fas ligation activated JNK in RTC expressing low levels of Fas, but not in apoptosis-sensitive RTC with increased Fas expression. Dominant negative JNK co-expression failed to inhibit apoptosis in RTC expressing high levels of Fas, suggesting that JNK is neither necessary, nor sufficient, for Fas-dependent apoptosis. CONCLUSIONS: At high levels of expression, RTC Fas promotes apoptosis in a JNK-independent manner. At low basal expression, Fas induces JNK activation, but not apoptosis, consistent with novel roles for RTC Fas as a mediator of cell stress or chronic inflammation.

Activation of EphA receptor tyrosine kinase inhibits the Ras/MAPK pathway.

Interactions between Eph receptor tyrosine kinases (RTKs) and membrane-anchored ephrin ligands critically regulate axon pathfinding and development of the cardiovascular system, as well as migration of neural cells. Similar to other RTKs, ligand-activated Eph kinases recruit multiple signalling and adaptor proteins, several of which are involved in growth regulation. However, in contrast to other RTKs, activation of Eph receptors fails to promote cell proliferation or to transform rodent fibroblasts, indicating that Eph kinases may initiate signalling pathways that are distinct from those transmitted by other RTKs. Here we show that stimulation of endogenous EphA kinases with ephrin-A1 potently inhibits the Ras/MAPK cascade in a range of cell types, and attenuates activation of mitogen-activated protein kinase (MAPK) by receptors for platelet-derived growth factor (PDGF), epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF). In prostatic epithelial cells and endothelial cells, but not fibroblasts, treatment with ephrin-A1 inhibits cell proliferation. Our results identify EphA kinases as negative regulators of the Ras/MAPK pathway that exert anti-mitogenic functions in a cell-type-specific manner.

A family-based strategy to identify genes for diabetic nephropathy.

Diabetic nephropathy (DN) clusters in families and specific ethnic groups, suggesting a genetic basis of disease transmission. Identification of DN susceptibility loci should reveal new therapeutic targets but requires accurate phenotyping. A powerful family-based strategy, which is novel to the pursuit of nephropathy genes in type 2 diabetes, is being used to collect a sample for candidate gene and genome scan analyses. Sib pairs that include DN index cases plus (1) sibs concordant for type 2 diabetes and DN (affected sib pairs [ASPs]) and (2) sibs concordant for type 2 diabetes but discordant for DN (discordant sib pairs [DSPs]) are targeted specifically for recruitment. Type 2 diabetes and DN phenotype criteria for index cases include diabetes onset after 38 years of age, duration 10 years or longer, no initial insulin treatment, diabetic retinopathy, end-stage renal disease (ESRD), and history of nephrotic proteinuria. ESRD patients were screened by questionnaire and medical record review (n = 2114). Of 666 patients with ESRD secondary to DN, 227 had a family history of ESRD, 150 had a living diabetic sib, and 124 families were enrolled. Sixty-five families, with 86 diabetic relative pairs (69 sibs, 17 children), have been completely phenotyped. If nephropathy in diabetic sibs is defined as albuminuria greater than 0.3 g/24 h, 31 ASPs and 26 DSPs (diabetic sib with albuminuria <0.3 g/24 h) were identified. Applying more stringent criteria, only 12 ASPs (sib with diabetes >10 years, diabetic retinopathy, and nephrotic proteinuria) and 9 DSPs (sib with diabetes >10 years and normal urine albumin excretion) were identified. Extrapolating from the number of subjects recruited using stringent phenotyping criteria, nearly 10,000 ESRD patients are required for screening to achieve adequate statistical power for linkage analysis (80% power to detect locus-specific relative risk of 2.2 at a lod score of 3.0). Careful phenotyping requires a large recruitment effort but is necessary to reduce population heterogeneity, a strategy that increases the likelihood of identifying DN loci.

Inaccuracy of clinical phenotyping parameters for hypertensive nephrosclerosis.

BACKGROUND: Multiple studies suggest that hypertension-induced end-stage renal disease (ESRD) is heritable. Identification of nephropathy susceptibility genes absolutely requires accurate phenotyping, but the clinical hypertensive nephrosclerosis (HN) phenotype is poorly characterized. We hypothesized that many patients with HN as the indicated cause of ESRD on the Health Care Financing Administration (HCFA) 2728 form, fail to satisfy stringent HN phenotyping criteria. METHODS: Since renal biopsy documentation of HN is uncommon, clinical parameters for HN phenotype were applied: family history of hypertension, left ventricular hypertrophy, proteinuria <0.5 g/day, and hypertension preceding renal dysfunction (Schlessinger et al., 1994) or urine protein:creatinine (prot:creat) ratio <2.0 and no evidence of other renal diseases (AASK Trial Group, 1997). RESULTS: ESRD patients (n=607, 73% African American, 25% Caucasian) were enrolled in a study to identify HN susceptibility genes. HN was the most common cause of ESRD according to HCFA 2728 forms (37% prevalence). Phenotyping of randomly selected patients with HN from the total cohort revealed that 4/100 subjects satisfied the Schlessinger criteria, and 28/91 African Americans met AASK criteria for HN. From these figures, the adjusted prevalence of HN was only 1.5-13.5%. Of patients that could not be phenotyped for HN, 14 were misdiagnosed, 14 had urine prot:creat >2.0, and insufficient data were available in the remainder. Four patients underwent renal biopsy, but histology from only one was consistent with HN. If the HN phenotype definitions are revised to exclude 'hypertension preceding renal dysfunction', or proteinuria limits, then 44/100 and 39/91 patients respectively satisfy clinical phenotyping parameters for HN. CONCLUSIONS: (i) We provide the strongest evidence to date that HN is less frequent in an ESRD population than commonly assumed if strict clinical criteria are used; many patients clinically diagnosed with HN may have undetected, treatable renal disease from other causes; (ii) relaxing HN phenotype criteria may erroneously include patients with glomerular diseases and secondary hypertension; (iii) reliance on HCFA 2728 diagnoses will confound identification of HN susceptibility genes; (iv) to attain adequate statistical power for genotype analysis, rigorous HN phenotyping will require screening an extremely large number of patients, which can be reasonably accomplished only in a multi-centre trial design.

Serum C-peptide concentrations poorly phenotype type 2 diabetic end-stage renal disease patients.

BACKGROUND: A homogeneous patient population is necessary to identify genetic factors that regulate complex disease pathogenesis. In this study, we evaluated clinical and biochemical phenotyping criteria for type 2 diabetes in end-stage renal disease (ESRD) probands of families in which nephropathy is clustered. C-peptide concentrations accurately discriminate type 1 from type 2 diabetic patients with normal renal function, but have not been extensively evaluated in ESRD patients. We hypothesized that C-peptide concentrations may not accurately reflect insulin synthesis in ESRD subjects, since the kidney is the major site of C-peptide catabolism and would poorly correlate with accepted clinical criteria used to classify diabetics as types 1 and 2. METHODS: Consenting diabetic ESRD patients (N = 341) from northeastern Ohio were enrolled. Clinical history was obtained by questionnaire, and predialysis blood samples were collected for C-peptide levels from subjects with at least one living diabetic sibling (N = 127, 48% males, 59% African Americans). RESULTS: Using clinical criteria, 79% of the study population were categorized as type 1 (10%) or type 2 diabetics (69%), while 21% of diabetic ESRD patients could not be classified. In contrast, 98% of the patients were classified as type 2 diabetics when stratified by C-peptide concentrations using criteria derived from the Diabetes Control and Complications Trial Research Group (DCCT) and UREMIDIAB studies. Categorization was concordant in only 70% of ESRD probands when C-peptide concentration and clinical classification algorithms were compared. Using clinical phenotyping criteria as the standard for comparison, C-peptide concentrations classified diabetic ESRD patients with 100% sensitivity, but only 5% specificity. The mean C-peptide concentrations were similar in diabetic ESRD patients (3.2 +/- 1.9 nmol/L) and nondiabetic ESRD subjects (3.5 +/- 1.7 nmol/L, N = 30, P = NS), but were 2.5-fold higher compared with diabetic siblings (1.3 +/- 0.7 nmol/L, N = 30, P < 0.05) with normal renal function and were indistinguishable between type 1 and type 2 diabetics. Although 10% of the diabetic ESRD study population was classified as type 1 diabetics using clinical criteria, only 1.5% of these patients had C-peptide levels less than 0.20 nmol/L, the standard cut-off used to discriminate type 1 from type 2 diabetes in patients with normal renal function. However, the criteria of C-peptide concentrations> 0.50 nmol/L and diabetes onset in patients who are more than 38 years old identify type 2 diabetes with a 97% positive predictive value in our ESRD population. CONCLUSIONS: Accepted clinical criteria, used to discriminate type 1 and type 2 diabetes, failed to classify a significant proportion of diabetic ESRD patients. In contrast to previous reports, C-peptide levels were elevated in the majority of type 1 ESRD diabetic patients and did not improve the power of clinical parameters to separate them from type 2 diabetic or nondiabetic ESRD subjects. Accurate classification of diabetic ESRD patients for genetic epidemiological studies requires both clinical and biochemical criteria, which may differ from norms used in diabetic populations with normal renal function.

Use of serial analysis of gene expression to generate kidney expression libraries.

Chronic renal disease initiation and progression remain incompletely understood. Genome-wide expression monitoring should clarify mechanisms that cause progressive renal disease by determining how clusters of genes coordinately change their activity. Serial analysis of gene expression (SAGE) is a technique of expression profiling, which permits simultaneous, comparative, and quantitative analysis of gene-specific, 9- to 13-bp sequence tags. Using SAGE, we have constructed a tag expression library from ROP-+/+ mouse kidney. Tag sequences were sorted by abundance, and identity was determined by sequence homology searching. Analyses of 3,868 tags yielded 1,453 unique kidney transcripts. Forty-two percent of these transcripts matched mRNA sequence entries with known function, 35% of the transcripts corresponded to expressed sequence tag (EST) entries or cloned genes, whose function has not been established, and 23% represented unidentified genes. Previously characterized transcripts were clustered into functional groups, and those encoding metabolic enzymes, plasma membrane proteins (transporters/receptors), and ribosomal proteins were most abundant (39, 14, and 12% of known transcripts, respectively). The most common, kidney-specific transcripts were kidney androgen-regulated protein (4% of all transcripts), sodium-phosphate cotransporter (0.3%), renal cytochrome P-450 (0.3%), parathyroid hormone receptor (0.1%), and kidney-specific cadherin (0.1%). Comprehensively characterizing and contrasting gene expression patterns in normal and diseased kidneys will provide an alternative strategy to identify candidate pathways, which regulate nephropathy susceptibility and progression, and novel targets for therapeutic intervention.

Fatal hypermagnesemia.

Severe symptomatic hypermagnesemia is a rare clinical problem that predominantly results from excess exogenous magnesium intake in patients with renal failure. This report describes an elderly woman who was given a magnesium-containing cathartic for pre-operative bowel preparation in the context of unrecognized acute renal failure. She subsequently developed one of the highest serum magnesium concentrations ever reported. The hypermagnesemia was successfully treated with continuous arteriovenous hemodialysis, but she ultimately died from complications of hypermagnesemia, that included junctional bradycardia, myocardial infarction and respiratory failure. This case illustrates the importance of ensuring intact renal function prior to administering large quantities of oral magnesium. More specifically, large doses of magnesium salts should be avoided in patients with acute renal failure.

Involvement of Fas-dependent apoptosis in renal tubular epithelial cell deletion in chronic renal failure.

Renal tubular atrophy predicts a poor prognosis in chronic renal failure, but the molecular mechanisms that regulate tubular atrophy are unknown. Because the Fas apoptosis pathway has been implicated in disease pathogenesis and Fas is expressed in kidney, we hypothesized that Fas-mediated renal tubule epithelial cell (RTC) apoptosis contributes to tubular atrophy in chronic renal failure. Immunohistochemical analyses of renal sections from two murine models of progressive renal disease revealed increases in RTC Fas expression and apoptosis compared with tissue sections from age-matched control kidneys. Increased RTC apoptosis was not accompanied by compensatory hyperplasia, suggesting that RTCs targeted for Fas-dependent apoptotic deletion contribute to tubular atrophy. These data are supported by in vitro studies that showed that interleukin-1alpha or tumor necrosis factor-alpha, cytokines that are secreted in chronic renal failure, stimulated increases in Fas expression in cultured RTCs. Both murine kidney cortex and RTCs in culture demonstrated constitutive expression of Fas ligand, a feature that is characteristically restricted to lymphocytes and immune-privileged tissues and previously unrecognized in RTCs. Functional studies revealed that interleukin-1alpha-stimulated RTC Fas expression was accompanied by increased apoptosis, which was inhibited by blocking anti-Fas ligand antibodies. The data suggest that up-regulated RTC Fas binds to Fas ligand on adjacent RTCs, which then leads to RTC death by fratricide. We propose this pathway as an initiating mechanism of tubular atrophy.

Genetic susceptibility to end-stage renal disease.

New methods have been developed to uncover the genotypes that result in complex diseases. End-stage renal disease is a complex disease, without a simple correspondence between genotype and phenotype. Both population-based and family-based epidemiological studies and analysis of model organisms suggest that the pathogenesis of end-stage renal disease may have a genetic component. A number of studies have analyzed candidate nephropathy genes with little success, but recently several well-designed studies of multiplex families with diabetic nephropathy have identified candidate nephropathy susceptibility loci. To date, kidney disease-oriented research has focused on effector mechanisms responsible for the initiation and progression of chronic renal disease. However, because end-stage renal disease is a complex disease, interruption of a single effector pathway is unlikely to result in significant therapeutic benefit. Further understanding of the pathogenesis of kidney disease and the development of new kidney disease therapies will require continued application of genetic and genomic tools to kidney disease research.