Brain Tissue Conductivity in Focal Cerebral Ischemia.

BACKGROUND: Cerebral ischemia leads to oxygen depletion with rapid breakdown of transmembrane transporters and subsequent impaired electrolyte haemostasis. Electric properties tomography (EPT) is a new contrast in MRI which delivers information on tissue electrical conductivity. In the clinical realm it has been mostly used for tumour mapping. Ischemic cerebral stroke is another promising but neglected application. It might deliver additional information on tissue viability and possible response to therapy. AIM: The aim of this study was to demonstrate tissue conductivity in a rodent model of stroke. Further, we aimed to compare electric conductivity in ischemic and non-ischemic cerebral tissue. MATERIALS AND METHODS: Two male Wistar rats were used in this study and were subjected to permanent MCAO. The animals were scanned in a 3 Tesla system (Philips Achieva/Best, the Netherlands) using a dedicated solenoid animal coil (Philips/Hamburg, Germany). In addition to diffusion weighted imaging (DWI), EPT was performed using a steady-state free-precession (SSFP) sequence (repetition time/echo time = 4.5/2.3 ms, measured voxel size = 0.6 × 0.6 × 1.2 mm3, flip angle = 38°, number of excitations = 4). From the transceive phase ϕ of these SSFP scans, conductivity σ was estimated by the equation σ = Δϕ/(2µ0ω) with Δ the Laplacian operator, µ0 the magnetic permeability, and ω the Larmor frequency. Subsequently, a median filter was applied, which was locally restricted to voxels with comparable signal magnitude. RESULTS: The animals exhibited an infarct as demonstrated on DWI. Conductivity within the infarcted region was 60-70 % of the conductivity of not affected contralateral tissue (0.39 ± 0.07 S/m and 0.31 ± 0.14 S/m vs. 0.64 ± 0.15 S/m and 0.66 ± 0.16 S/m, respectively). DISCUSSION: Infarcted tissue exhibited decreased conductivity. Further in-vivo experiments with examination of the influence of reperfusion status and temporal evolution of the infarcted areas should be conducted. Depiction of the ischemic penumbra and possibly subclassification of the DWI lesion still seems to be a fruitful target for further studies.

Alternative Polyadenylation of ABC Transporters of the C-Family (ABCC1, ABCC2, ABCC3) and Implications on Posttranscriptional Micro-RNA Regulation.

ATP-binding cassette (ABC) transporters represent a large group of efflux pumps that are strongly involved in the pharmacokinetics of various drugs and nutrient distribution. It was recently shown that micro-RNAs (miRNAs) may significantly alter their expression as proven, e.g., for miR-379 and ABCC2 However, alternative mRNA polyadenylation may result in expression of 3'-untranslated regions (3'-UTRs) with varying lengths. Thus, length variants may result in presence or absence of miRNA binding sites for regulatory miRNAs with consequences on posttranscriptional control. In the present study, we report on 3'-UTR variants of ABCC1, ABCC2, and ABCC3 mRNA. Applying in vitro luciferase reporter gene assays, we show that expression of short ABCC2 3'-UTR variants leads to a significant loss of miR-379/ABCC2 interaction and subsequent upregulation of ABCC2 expression. Furthermore, we show that expression of ABCC2 3'-UTR lengths varies significantly between human healthy tissues but is not directly correlated to the respective protein level in vivo. In conclusion, the presence of altered 3'-UTR lengths in ABC transporters could lead to functional consequences regarding posttranscriptional gene expression, potentially regulated by alternative polyadenylation. Hence, 3'-UTR length variability may be considered as a further mechanism contributing to variability of ABCC transporter expression and subsequent drug variation in drug response. SIGNIFICANCE STATEMENT: micro-RNA (miRNA) binding to 3'-untranslated region (3'-UTR) plays an important role in the control of ATP-binding cassette (ABC)-transporter mRNA degradation and translation into proteins. We disclosed various 3'-UTR length variants of ABCC1, C2, and C3 mRNA, with loss of mRNA seed regions partly leading to varying and tissue-dependent interaction with miRNAs, as proven by reporter gene assays. Alternative 3'-UTR lengths may contribute to variable ABCC transporter expression and potentially explains inconsistent findings in miRNA studies.

Warming before and after epidural block before general anaesthesia for major abdominal surgery prevents perioperative hypothermia: A randomised controlled trial.

BACKGROUND: Epidural analgesia (EDA) is known to be an independent risk factor for perioperative hypothermia and its many known adverse effects. Combined general and epidural anaesthesia decreases intraoperative core temperature more rapidly than general anaesthesia alone. Hence, adequate warming procedures are needed for these patients. OBJECTIVE: We evaluated the effects of active skin-surface warming before and/or after initiation of EDA during general anaesthesia as a procedure to prevent perioperative hypothermia. DESIGN: A randomised controlled trial. SETTING: Department of Anaesthesiology in a general hospital in Germany from January 2013 until August 2014. PATIENTS: After obtaining written informed consent, we included 99 adult patients undergoing elective major abdominal surgery under combined general anaesthesia and EDA with an expected duration of surgery of at least 120 min. Patients were excluded if they were under 18 years of age, classified as American Society of Anesthesiologists' physical status 4 or higher or if patients refused EDA. INTERVENTIONS: Patients were randomly assigned to one of three groups and received either only passive insulation, 15 min of active air-forced warming after EDA and before induction of general anaesthesia, or two periods, each of 15 min, of active air-forced warming before and after EDA. Core and skin temperatures were measured at several time points throughout the study. MAIN OUTCOME MEASURES: The primary outcome measure was the incidence of hypothermia on arrival in the ICU. The secondary outcome measure was the incidence of postoperative shivering. In addition, the perioperative change in body core temperature was recorded. RESULTS: Without prewarming (n = 32), 72% of patients became hypothermic (<36°C) at the end of anaesthesia. Fifteen minutes of warming after insertion of the epidural catheter and before initiation of general anaesthesia reduced the incidence of postoperative hypothermia to 6% (n = 33). After two periods of 15 min of warming before and after insertion of the epidural catheter, no patient became hypothermic (n = 34). Prewarming in either 'warming' group prevents the initial temperature drop which was observed in the control group. CONCLUSION: Warming for 15 min before and after initiation of EDA in patients receiving combined anaesthesia is effective in preventing postoperative hypothermia. TRIAL REGISTRATION: This trial was registered with ClinicalTrials.gov (identifier: NCT01795482).

Intraoperative temperature monitoring with zero heat flux technology (3M SpotOn sensor) in comparison with sublingual and nasopharyngeal temperature: An observational study.

BACKGROUND: Perioperative hypothermia is common in patients undergoing general anaesthesia and is associated with important adverse events. The 'gold standard' for monitoring body core temperature - the pulmonary artery catheter - is invasive and unsuitable for most patients. For routine clinical practice, other sites and methods of temperature monitoring are commonly used. OBJECTIVE: The aim of this study was to evaluate a new temperature sensor (3M SpotOn) using the 'zero heat flux' method attached to the forehead, and compare it to sublingual and nasopharyngeal sensors in terms of correlation, accuracy and precision. DESIGN: An observational study. SETTING: University Medical Center Schleswig Holstein, Campus Kiel, Germany from October 2013 to January 2014. PATIENTS: One hundred and twenty patients scheduled for elective gynaecological or trauma surgery undergoing general anaesthesia were enrolled into this study. Data of 83 patients were finally analysed. Patients with unexpected blood loss, haemodynamic instability determined by the need for continuous norepinephrine infusion and/or need for postoperative ventilation were excluded from this study. INTERVENTION: Temperature monitoring was established after induction of anaesthesia with sublingual and nasopharyngeal probes, and the SpotOn sensor. MAIN OUTCOME MEASURES: Body temperature was measured 15, 45 and 75 min after induction of anaesthesia from sublingual and nasopharyngeal probes and the 3M SpotOn sensor at precisely the same moment. RESULTS: Analysis of 83 data sets revealed that 3M SpotOn temperatures were almost identical with nasopharyngeal temperatures (mean difference 0.07 °C; P = 0.1424) and slightly lower than sublingual temperatures by 0.35 °C (P < 0.0001). Coefficients of determination (r) for both methods were between 0.87 (SpotOn vs. nasopharyngeal measurement) and 0.77 (SpotOn vs. sublingual measurement). Bland-Altman analysis revealed a bias (SD) between 0.07 °C (0.21) (SpotOn vs. nasopharyngeal) and -0.35 °C (0.29) (SpotOn vs. sublingual measurement). CONCLUSION: With respect to correlation, accuracy and precision, the 3M SpotOn sensor provides a good measurement of body temperature in comparison to the nasopharyngeal probe and an acceptable measurement in comparison with sublingual thermometry. It is adequate for clinical use. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02031159.

Mitochondrial gene polymorphisms that protect mice from colitis.

BACKGROUND & AIMS: Dysregulated energy homeostasis in the intestinal mucosa frequently is observed in patients with ulcerative colitis (UC). Intestinal tissues from these patients have reduced activity of the mitochondrial oxidative phosphorylation (OXPHOS) complex, so mitochondrial dysfunction could contribute to the pathogenesis of UC. However, little is known about the mechanisms by which OXPHOS activity could be altered. We used conplastic mice, which have identical nuclear but different mitochondrial genomes, to investigate activities of the OXPHOS complex. METHODS: Colitis was induced in C57BL/6J wild-type (B6.B6) and 3 strains of conplastic mice (B6.NZB, B6.NOD, and B6.AKR) by administration of dextran sodium sulfate or rectal application of trinitrobenzene sulfonate. Colon tissues were collected and analyzed by histopathology, immunohistochemical analysis, and immunoblot analysis; we also measured mucosal levels of adenosine triphosphate (ATP) and reactive oxygen species, OXPHOS complex activity, and epithelial cell proliferation and apoptosis. RESULTS: We identified mice with increased mucosal OXPHOS complex activities and levels of ATP. These mice developed less-severe colitis after administration of dextran sodium sulfate or trinitrobenzene sulfonate than mice with lower mucosal levels of ATP. Colon tissues from these mice also had increased enterocyte proliferation and transcription factor nuclear factor-κB activity, which have been shown to protect the mucosal barrier-defects in these processes have been associated with inflammatory bowel disease. CONCLUSIONS: Variants in mitochondrial DNA that increase mucosal levels of ATP protect mice from colitis. Increasing mitochondrial ATP synthesis in intestinal epithelial cells could be a therapeutic approach for UC.

[Anesthetic drug interactions]. / Medikamenteninteraktionen--In der Anästhesie.

Pharmaceutical, pharmacokinetic and pharmacodynamic drug-drug interactions (DDI) can complicate or facilitate anesthesia. Knowledge of the basic DDI mechanisms and DDI databases helps to avoid unwanted DDIs and to optimize wanted DDIs such as antidotes or desired synergism. Concerning pharmaceutical DDI (=incompatibilities) special attention must be paid to very acidic or basic drugs, polyvalent ions such as calcium and emulsions like propofol. Inducers or inhibitors of cytochrome p450 3A4 can complicate postoperative therapy of raised blood pressure or pain (pharmacokinetic DDI). Pharmacodynamik DDIs like the impact of many drugs on blood pressure are the day-to-day armamentarium for anesthetists.

Quality Assessment Framework of Clinical Routine Data for Secondary Use.

To systematically and comprehensively identify data issues in large clinical datasets, we adopted a harmonized data quality assessment framework with Python scripts before integrating the data into FHIR® for secondary use. We also added a preliminary step of categorizing data fields within the database scheme to facilitate the implementation of the data quality framework. As a result, we demonstrated the efficiency and comprehensiveness of detecting data issues using the framework. In future steps, we plan to continually utilize the framework to identify data issues and develop strategies for improving our data quality.

Phenotype-Genotype Correlation Applying a Cocktail Approach and an Exome Chip Analysis Reveals Further Variants Contributing to Variation of Drug Metabolism.

Although great progress has been made in the fine-tuning of diplotypes, there is still a need to further improve the predictability of individual phenotypes of pharmacogenetically relevant enzymes. The aim of this study was to analyze the additional contribution of sex and variants identified by exome chip analysis to the metabolic ratio of five probe drugs. A cocktail study applying dextromethorphan, losartan, omeprazole, midazolam, and caffeine was conducted on 200 healthy volunteers. CYP2D6, 2C9, 2C19, 3A4/5, and 1A2 genotypes were analyzed and correlated with metabolic ratios. In addition, an exome chip analysis was performed. These SNPs correlating with metabolic ratios were confirmed by individual genotyping. The contribution of various factors to metabolic ratios was assessed by multiple regression analysis. Genotypically predicted phenotypes defined by CPIC discriminated very well the log metabolic ratios with the exception of caffeine. There were minor sex differences in the activity of CYP2C9, 2C19, 1A2, and CYP3A4/5. For dextromethorphan (CYP2D6), IP6K2 (rs61740999) and TCF20 (rs5758651) affected metabolic ratios, but only IP6K2 remained significant after multiple regression analysis. For losartan (CYP2C9), FBXW12 (rs17080138), ZNF703 (rs79707182), and SLC17A4 (rs11754288) together with CYP diplotypes, and sex explained 50% of interindividual variability. For omeprazole (CYP2C19), no significant influence of CYP2C:TG haplotypes was observed, but CYP2C19 rs12777823 improved the predictability. The comprehensive genetic analysis and inclusion of sex in a multiple regression model significantly improved the explanation of variability of metabolic ratios, resulting in further improvement of algorithms for the prediction of individual phenotypes of drug-metabolizing enzymes.

Correlation, accuracy, precision and practicability of perioperative measurement of sublingual temperature in comparison with tympanic membrane temperature in awake and anaesthetised patients.

BACKGROUND AND OBJECTIVE: The prevention of inadvertent perioperative hypothermia requires precise, reliable and practical methods of temperature measurement in both awake and anaesthetised patients. Different methods and sites of monitoring have been evaluated, but many are imprecise, unusable in awake patients, difficult to apply or too invasive, especially for minor surgery. The aim of this study was to evaluate the performance of perioperative sublingual and tympanic temperature measurement in awake and anaesthetised patients. METHODS: We enrolled 171 patients, aged 18-75 years, scheduled for surgery with duration less than 1 h under general anaesthesia. Spearman's rank correlation and Bland-Altman analysis for assessment of correlation, accuracy and precision of both methods were determined analysing 171 independent paired values at three different measurement times. RESULTS: Sublingual temperatures were significantly higher than tympanic temperatures by 0.1-0.2°C. The coefficient of determination (r) of both methods was between 0.50 and 0.59, and Bland-Altman analysis revealed a bias (SD) of between -0.09 (0.21) and -0.15 (0.24)°C. CONCLUSION: The accuracy and precision of sublingual temperature measurement were adequate for clinical use, and there was a high correlation with tympanic temperature monitoring. Sublingual temperature measurement has been demonstrated as a good and practical modality for perioperative temperature monitoring in both awake and anaesthetised patients.

Genome­wide expression and methylation analyses reveal aberrant cell adhesion signaling in tyrosine kinase inhibitor­resistant CML cells.

Although chronic myeloid leukemia (CML) can be effectively treated using BCR­ABL1 kinase inhibitors, resistance due to kinase alterations or to BCR­ABL1 independent mechanisms remain a therapeutic challenge. For the latter, the underlying mechanisms are widely discussed; for instance, gene expression changes, epigenetic factors and alternative signaling pathway activation. In the present study, in vitro­CML cell models of resistance against the tyrosine kinase inhibitors (TKIs) imatinib (0.5 and 2 µM) and nilotinib (0.1 µM) with biological replicates were generated to identify novel mechanisms of resistance. Subsequently, genome­wide mRNA expression and DNA methylation were analyzed. While mRNA expression patterns differed largely between biological replicates, there was an overlap of 71 genes differentially expressed between cells resistant against imatinib or nilotinib. Moreover, all TKI resistant cell lines demonstrated a slight hypermethylation compared with native cells. In a combined analysis of 151 genes differentially expressed in the biological replicates of imatinib resistance, cell adhesion signaling, in particular the cellular matrix protein fibronectin 1 (FN1), was significantly dysregulated. This gene was also downregulated in nilotinib resistance. Further analyses showed significant FN1­downregulation in imatinib resistance on mRNA (P<0.001) and protein level (P<0.001). SiRNA­mediated FN1­knockdown in native cells reduced cell adhesion (P=0.02), decreased imatinib susceptibility visible by higher Ki­67 expression (1.5­fold, P=0.04) and increased cell number (1.5­fold, P=0.03). Vice versa, recovery of FN1­expression in imatinib resistant cells was sufficient to partially restore the response to imatinib. Overall, these results suggested a role of cell adhesion signaling and fibronectin 1 in TKI resistant CML and a potential target for novel strategies in treatment of resistant CML.

High-dose spironolactone lacks effectiveness in treatment of fibromyalgia (RCT).

BACKGROUND: Spironolactone (SPL) is a reversible mineralocorticoid receptor (MR) and androgen receptor (AR) antagonist which attracts pharmacotherapeutic interest not only because of its beneficial effects in heart failure but also because of the pathogenetic roles of MR and AR activities in neuropsychiatric diseases. Recently, beneficial and rapid-onset effects of SPL have been documented in a case series of women with fibromyalgia syndrome (FMS). To reaffirm this observation, we performed a double-blind placebo-controlled randomized clinical trial (RCT). METHODS: A total of 69 patients were screened, 56 patients were eligible and randomized to SPL or placebo (each n = 28). Forty-three patients completed the clinical trial to the last visit (n = 21 and n = 22). After a run-in phase of 50 and 100 mg/day, 200 mg/day SPL or placebo were applied between days 7 and 28. Primary outcome was the change in the FIQ-G score (Fibromyalgia Impact Questionnaire, German version). Secondary outcome parameters were the changes in pain (numeric rating scale, NRS), mood (ADS), quality of life (SF-36) and change in FIQ scores 14 days after the end of the medication. RESULTS: SPL of 200 mg/day did not change significantly either the primary or the secondary end points. SPL evoked a transient rise in serum potassium and a transient fall in GFR maximal after 2 weeks, but without clinical relevance. CONCLUSIONS: SPL at 200 mg/day does not improve symptoms in women with FMS, but was considered not to cause harm. SIGNIFICANCE: The mineralocorticoid receptor and androgen receptor antagonist spironolactone is repeatedly tested for its therapeutic effectivity against neuropsychiatric disorders. The present RCT demonstrated that 200 mg spironolactone does not change the symptoms of the fibromyalgia syndrome (FMS) in adult women. Between 2 and 4 weeks, spironolactone evokes a transient decrease in GFR and increase in serum potassium. Spironolactone cannot be recommended for the treatment of FMS.

Gliflozins for the Treatment of Congestive Heart Failure and Renal Failure in Type 2 Diabetes.

BACKGROUND: Gliflozins are effective drugs for the treatment of type 2 diabetes. They inhibit sodium glucose cotransporter 2 in the proximal renal tubule, leading to increased glucose excretion. On the basis of findings from relevant studies, gliflozins are also increasingly used in clinical practice to treat congestive heart failure and renal failure. METHODS: This review is based on pertinent publications retrieved from a selective literature search in PubMed and GoogleScholar. RESULTS: Cardiovascular safety studies revealed early on that gliflozins can lower the hospitalization rate of patients suffering from congestive heart failure with a reduced leftventricular ejection fraction (HFrEF). They also showed favorable effects on multiple renal endpoints. In recent years, studies such as DAPA-HF and CREDENCE have further documented the benefit of gliflozins in the treatment of congestive heart failure and renal failure in patients with type 2 diabetes, and gliflozins have accordingly been incorporated into the pertinent guidelines. In the recently published EMPEROR-Reduced trial, empagliflozin was found to significantly lower the frequency of a combined cardiovascular endpoint in patients with HFrEF (19.4 % versus 24.7%; hazard ratio [HR] 0.75; 95% confidence interval [0.65; 0.86]; number needed to treat [NNT] 19, p <0.001). In the DAPA-CKD trial, which was also recently published, dapagliflozin was found to significantly lower the frequency of a combined renal endpoint (9.2% versus 14.5%; HR 0.61 [0.51; 0.72]; NNT 19; p <0.001). CONCLUSION: On the basis of findings from specific studies, gliflozins will henceforth be a major class of drug for the treatment of HFrEF and renal failure, independently of the presence of type 2 diabetes.

Adjuvant Effect of Orally Applied Preparations Containing Non-Digestible Polysaccharides on Influenza Vaccination in Healthy Seniors: A Double-Blind, Randomised, Controlled Pilot Trial.

Senior individuals can suffer from immunosenescence and novel strategies to bolster the immune response could contribute to healthy ageing. In this double-blind, randomised, controlled pilot trial, we investigated the ability of non-digestible polysaccharide (NPS) preparations to enhance the immune response in a human vaccination model. In total, 239 subjects (aged 50-79 years) were randomised to consume one of five different NPS (yeast ß-glucan (YBG), shiitake ß-glucan (SBG), oat ß-glucan (OBG), arabinoxylan (AX), bacterial exopolysaccharide (EPS)) or control (CTRL) product daily for five weeks. After two weeks of intervention, subjects were vaccinated with seasonal influenza vaccine. The post-vaccination increases in haemagglutination inhibition antibody titres and seroprotection rate against the influenza strains were non-significantly enhanced in the NPS intervention groups compared to CTRL. Specifically, a trend towards a higher mean log2 fold increase was observed in the AX group (uncorrected p = 0.074) combined with a trend for an increased seroprotection rate, AX group (48.7%) compared to CTRL (25.6%) (uncorrected p = 0.057), for the influenza A H1N1 strain. Subjects consuming AX also had a reduced incidence of common colds compared to CTRL (1 vs. 8; p = 0.029 in Fisher exact test). No adverse effects of NPS consumption were reported. The findings of this pilot study warrant further research to study AX as an oral adjuvant to support vaccine efficacy.

Interaction of morphine but not fentanyl with cerebral alpha2-adrenoceptors in alpha2-adrenoceptor knockout mice.

OBJECTIVES: alpha(2)-Adrenergic and mu-opioid receptors belong to the rhodopsin family of G-protein coupled receptors and mediate antinociceptive effects via similar signal transduction pathways. Previous studies have revealed direct functional interactions between both receptor systems including synergistic and additive effects. To evaluate underlying mechanisms, we have studied whether morphine and fentanyl interacted with alpha(2)-adrenoceptor-subtypes in mice lacking one individual alpha(2)-adrenoceptor-subtype (alpha(2)-adrenoceptor knockout). METHODS: Opioid interaction with alpha(2)-adrenoceptors was investigated by quantitative receptor autoradiography in brain slices of alpha(2A)-, alpha(2B)- or alpha(2C)-adrenoceptor deficient mice. Displacement of the radiolabelled alpha(2)-adrenoceptor agonist [(125)I]paraiodoclonidine from alpha(2)-adrenoceptors in different brain regions by increasing concentrations of morphine, fentanyl and naloxone was analysed. The binding affinity of both opioids to alpha(2)-adrenoceptor subtypes in different brain regions was quantified. KEY FINDINGS: Morphine but not fentanyl or naloxone provoked dose-dependent displacement of [(125)I]paraiodoclonidine from all alpha(2)-adrenoceptor subtypes in the brain regions analysed. Binding affinity was highest in cortex, medulla oblongata and pons of alpha(2A)-adrenoceptor knockout mice. CONCLUSIONS: Our results indicated that morphine interacted with alpha(2)-adrenoceptors showing higher affinity for the alpha(2B) and alpha(2C) than for the alpha(2A) subtype. In contrast, fentanyl and naloxone did not show any relevant affinity to alpha(2)-adrenoceptors. This effect may have an impact on the pharmacological actions of morphine.

[Hypoglycemic risk of insulinotropic drugs]. / Hypoglykämie bei insulinotropen Substanzen.

Orally available insulinotropics that directly close K(ATP)-channels, such as sulfonylureas and glinides, differ in their pharmacokinetics and -dynamics (PK/PD). This results in different risks for their incidence of hypoglycemic episodes. Glibenclamide (USAN: glyburide) has the highest risk, followed by glimepiride. Glinides reveal a low risk of hypoglycemia due to their short duration of drug effect. Apart from PK/PD, clinically more relevant factors determine incidences of hypoglycemia. Adequate supervision at initial prescription or switch of insulinotropic drugs, comedication and patient compliance superimpose these pharmacological differences.

Mapping Medication Metadata from the ABDA Data Model to an OpenEHR Medication Archetype: A Qualitative Analysis.

Integrating data from various source systems to gain knowledge and meaningful data about patients for care and research is challenging. This work demonstrates how medication knowledge data from the database of the Federal Union of German Associations of Pharmacists (ABDA) can be used for storing and annotating medicinal products in an openEHR medication archetype.

Linking pre-existing biorepositories for medical research: the PopGen 2.0 Network.

The significance of human biorepositories for modern medical research, particularly for comprehensive population-based genetic analyses, is constantly growing. While large and centralized institutions are usually considered best suited to meet the increasing demand for high-quality "biobanks," most medical research institutions still host rather heterogeneous and fragmented biobanking activities, undertaken by clinical departments with oftentimes rather different scientific scope. Undoubtedly, most clinicians and medical researchers would appreciate infrastructural support in terms of the storage and handling of their biosamples, but they are also likely to expect access to their samples avoiding extensive formal requirements. We report on the establishment of the PopGen 2.0 Network (P2N), an overarching alliance of initially seven biobanks from Northern Germany which adopted a joint but lean governance structure and use-and-access policy for their samples and data. In addition, the members of P2N have pursued an intense collaboration on ethical, legal and social issues and maintain a common IT infrastructure. The implementation of P2N has substantially improved the prospects of biobank-based research at the participating institutions. The network may thus serve as a role model for similar initiatives geared at linking pre-existing biorepositories for the benefit of research quality, efficiency, and transparency.

Correction to "Asymmetrically hypointense veins on T2*w imaging and susceptibility-weighted imaging in ischemic stroke" [World J Radiol 2013; 5(4): 156-165].

[This corrects the article on p. 4 in vol. 5, PMID: 23671751.].