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The transcription factor CCAAT-enhancer binding factor alpha (C/ebpα) is a master controller of myeloid differentiation that is expressed as long (p42) and short (p30) isoform. Mutations within the CEBPAgene selectively deleting p42 are frequent in human acute myeloid leukemia. Here we investigated the individual genomics and transcriptomics of p42 and p30. Both proteins bound to identical sites across the genome. For most targets, they induced a highly similar transcriptional response with the exception of a few isoform specific genes. Amongst those we identified early growth response 1 (Egr1) and tribbles1 (Trib1) as key targets selectively induced by p42 that are also underrepresented in CEBPA-mutated AML. Egr1 executed a program of myeloid differentiation and growth arrest. Oppositely, Trib1 established a negative feedback loop through activation of Erk1/2 kinase thus placing differentiation under control of signaling. Unexpectedly, differentiation elicited either by removal of an oncogenic input or by G-CSF did not peruse C/ebpα as mediator but rather directly affected the cell cycle core by upregulation of p21/p27 inhibitors. This points to functions downstream of C/ebpα as intersection point where transforming and differentiation stimuli converge and this finding offers a new perspective for therapeutic intervention.

This case study deals with the design of a hybrid system for the prevention of thermal events in mining waste disposal sites and landfills. The overall design, real implementation, optimization, and experimental verification of the functionality of the entire system are described in detail. Both experimental platforms are built on the Internet of Things (long range wide area network (LoRaWAN) and Sigfox) basis and meet the conditions for autonomous long-term on-site monitoring. The data collected are periodically transmitted wirelessly to a database repository, which processes relevant parameters for the operators of dispatching workplaces. The study is focused on a combination of surface and depth measurement methods. The experimental results clearly confirm the functionality of the proposed solutions, which will enable timely interventions and elimination of underground and surface combustions. Thanks to centralized data collection, a unique database has also been created, which can be used for the implementation of prediction algorithms (based, for example, on machine learning or artificial intelligence).

ABSTRACTBackgroundKey to optimizing Computational Thinking (CT) instruction is a precise understanding of the underlying cognitive skills. Román-González et al. (2017) reported unique contributions of spatial abilities and reasoning, whereas arithmetic was not significantly related to CT. Disentangling the influence of spatial and numerical skills on CT is important, as neither should be viewed as monolithic traits.ObjectiveThis study aimed (1) to replicate the results of a previous study by Román-González et al. (Computers in Human Behaviour 72), and (2) to extend this research by investigating other theoretically relevant constructs. Specifying the contribution of reasoning (i.e. numerical, figural), numerical skills (i.e. arithmetic, algebra), and spatial skills (i.e. visualization, mental rotation, short-term memory) helps to better understand the cognitive mechanisms underlying CT.MethodWe investigated a sample of 132 students from Grades 7–8 (age range 12–15 years). Participants completed the Computational Thinking test, as well as a variety of psychometric assessments of reasoning, numerical, and spatial skills. To determine which cognitive skills are relevant for CT, we calculated bivariate correlations and performed a linear regression analysis.FindingsResults confirmed unique contributions of figural reasoning and visualization. Additional variance was explained by algebraic skills.ImplicationsWe conclude that CT engages cognitive mechanisms extending beyond reasoning and spatial skills.

Background: Transesophageal echocardiography visualizes the left atrium and its appendage, thrombi, and spontaneous echocardiographic contrast. objective: To assess the association of transesophageal echocardiographic characteristics with stroke or embolism in atrial fibrillation. Design: Multicenter observational follow-up study. Setting: Hospitals in Austria and Slovakia. Patients: 409 outpatients with nonrheumatic atrial fibrillation and without recent stroke. Intervention: Patients with thrombi received anticoagulation, and patients without thrombi received aspirin. Measurements: Primary events were stroke or embolism. Secondary events were death not caused by stroke or embolism and need for anticoagulation. Results: in the left atrium or left atrial appendage, 10 patients (2.5%) had thrombi and 47 (12%) had spontaneous echocardiographic contrast. The appendage had a mean ([+ or -] SD) length of 44 [+ or -] 10 mm, a mean width of 23 [+ or -] 6 mm, and a mean area of 5.8 [+ or -] 2.5 [cm.sub.2]. Follow-up ranged from 1 to 74 months (mean, 58 months). Fifty patients had stroke or embolism, 53 died of a cause other than stroke or embolism, and 38 required anticoagulation. On univariate analysis, thrombi (risk ratio, 3.9 [95% Cl, 1.4 to 10.1]; P = 0.009), length of the left atrial appendage (risk ratio, 1.6 [Cl, 1.05 to 2.5]; P = 0.03), and width of the left atrial appendage (risk ratio, 2.4 [Cl, 1.2 to 4.8]; P = 0.01) were associated with stroke or embolism. Multivariate analysis identified hypertension (risk ratio, 3.6 [Cl, 1.8 to 8.4]; P = 0.001), previous stroke (risk ratio, 3.7 [Cl, 1.5 to 7.5]; P = 0.002), and age (risk ratio, 1.1 [Cl, 1.0 to 1.1]; P [is less than] 0.001) as risk factors for stroke or embolism and provided evidence of an association between thrombi and stroke or embolism (risk ratio, 2.4 [Cl, 0.9 to 6.9]; P = 0.09). Conclusions: In outpatients with atrial fibrillation and without recent stroke, thrombi of the left atrium or left atrial appendage and length and width of the left atrial appendage were associated with stroke or embolism in univariate analysis. In a multivariate analysis, age, hypertension, and previous stroke were risk factors for stroke or embolism, and thrombi of the left atrium or left atrial appendage were possible risk factors. In these patients, history may be more useful than transesophageal echocardiography for the assessment of embolic risk., Old age, hypertension and a history of stroke may be better predictors of stroke in patients with atrial fibrillation than the presence of blood clots in the left atrium. Atrial fibrillation is a rapid contraction of the upper chambers of the heart, which are called atria. Researchers inserted an echocardiographic probe into the esophagus of 409 patients with atrial fibrillation to see if the left atrium contained a blood clot that could break off and travel to the brain. About 3% had a clot and the presence of a clot increased their risk of stroke. However, age, hypertension and history of stroke were more important risk factors.

* Objective: To determine the prevalence of venous thrombosis in patients with suspected paradoxical embolism. * Design: Observational study. * Patients: Two hundred sixty-four patients with clinically suspected embolic events underwent contrast transesophageal echocardiographic evaluation. Forty-nine patients (24 women, 25 men) had a patent foramen ovale. Forty-one patients had acute stroke, and 8 had acute limb ischemia. * Selling: Echocardiography laboratory of a community hospital. * Measurements: The presence of a patent foramen ovale was assessed by transesophageal contrast echocardiography. Forty-two patients had venographic evaluation of the lower-extremity venous system. * Results: Venous thrombosis was clinically suspected in 6 patients and documented in 24 of the 42 patients with patent foramen ovale who underwent venographic study (57%; 95% CI, 41% to 72%). Venous thrombosis was confined to calf or popliteal veins in 15 cases. Fifteen of 17 patients who had venographic evaluation within 7 days of the index event had thrombosis compared with 9 of 25 patients who had later evaluations (P = 0.001). More patients with venous thrombosis than without venous thrombosis had a history of previous thromboembolism (13 of 24 compared with 1 of 8, respectively; P = 0.001). * Conclusion: When a patent foramen ovale is detected in a patient with embolism, occult leg vein thrombosis is frequently present., Venous thrombosis of the leg may be common among patients with a paradoxical embolism. A paradoxical embolism is blockage of an artery by a blood clot originating in a vein. The blood clot has passed through a defective opening between the left and right side of the heart. Deep venous thrombosis is the development of a blood clot in a vein. Among 42 patients with a paradoxical embolism whose legs were X-rayed, 24 had documented venous thrombosis and six had suspected venous thrombosis. Fifteen patients had venous thrombosis that was limited to the calf or the popliteal veins. The popiliteal veins are located behind the knee.

Mixed-lineage leukemia (MLL) fusions are transcriptional activators that induce leukemia, with a dismal prognosis that mandates further elucidation of their transformation mechanism. In this study, knockdown of the direct MLL-ENL target gene polypyrimidine tract binding protein-1 (PTBP1) was rate limiting for cell proliferation and caused a metabolic phenotype associated with reduced glucose consumption and lactate production. This effect was accompanied by a reduction of splice isoform-2 of pyruvate kinase M (PKM2). Because PKM2 restricts glycolytic outflow to provide anabolic intermediates, we tested the consequences of glucose, energy, and Ser/Gly starvation for cell physiology. Administration of deoxyglucose, energetic decoupling with rotenone, and inhibition of Ser biosynthesis by CBR5884 had a significantly stronger influence on self-renewal and survival of transformed cells than on normal controls. In particular, inhibition of Ser synthesis, which branches off glycolysis caused accumulation of reactive oxygen species, DNA damage, and apoptosis, predominantly in leukemic cells. Depletion of exogenous Ser/Gly affected proliferation and self-renewal of murine and human leukemia samples, even though they are classified as nonessential amino acids. Response to Ser/Gly starvation correlated with glucose transport, but did not involve activation of the AMPK energy homeostasis system. Finally, survival times in transplantation experiments were significantly extended by feeding recipients a Ser/Gly-free diet. These results suggest selective starvation as an option for supportive leukemia treatment.

Managing complex software ecosystems, such as free open source software projects, is crucial for software-producing organizations. We present a framework that helps visualize complex ecosystem settings, gain insights on value engines, and describe relationships between the ecosystem partners.

Ectopic expression of the oncogenic transcription factor HoxA9 is a major cause of acute myeloid leukemia (AML). Here, we demonstrate that HoxA9 is a specific substrate of granule proteases. Protease knockout allowed the comprehensive determination of genome-wide HoxA9 binding sites by chromatin immunoprecipitation sequencing in primary murine cells and a human AML cell line. The kinetics of enhancer activity and transcription rates in response to alterations of an inducible HoxA9 were determined. This permitted identification of HoxA9-controlled enhancers and promoters, allocation to their respective transcription units, and discrimination against HoxA9-bound, but unresponsive, elements. HoxA9 triggered an elaborate positive-feedback loop that drove expression of the complete Hox-A locus. In addition, it controlled key oncogenic transcription factors Mycand Myband directly induced the cell cycle regulators Cdk6and CyclinD1, as well as telomerase, drawing the essential blueprint for perturbation of proliferation by leukemogenic HoxA9 expression.

Eleven-nineteen leukemia (ENL) is a chromatin reader present in complexes stimulating transcriptional elongation. It is fused to mixed-lineage leukemia (MLL) in leukemia, and missense mutations have been identified in Wilms tumor and acute myeloid leukemia. Here we demonstrate that ENL overcomes polycomb silencing through recruitment of PAF1 via the conserved YEATS domain, which recognizes acetylated histone H3. PAF1 was responsible for antirepressive activities of ENL in vitro, and it determined the transforming potential of MLL-ENL. MLL-ENL target loci showed supraphysiological PAF1 binding, hyperubiquitination of histone H2B and hypomodification with H2AUb, resulting in accelerated transcription rates. YEATS mutations induced a gain of function, transforming primary hematopoietic cells in vitro and in transplantation assays through aberrant transcription and H2B ubiquitination of Hoxa9 and Meis1. Mechanistically, H3 and PAF1 competed for ENL interaction, with activating mutations favoring PAF1 binding, whereas the MLL moiety provided a constitutive PAF1 tether allowing MLL fusions to circumvent H3 competition.

B cell chronic lymphocytic leukemia (B-CLL), the most common type of leukemia in adults, is still essentially incurable despite the development of novel therapeutic strategies. This reflects the incomplete understanding of the pathophysiology of this disease. A comprehensive proteome analysis of primary human B-CLL cells and B cells from younger as well as elderly healthy donors was performed. For comparison, the chronic B cell leukemia cell line JVM-13 was also included. A principal component analysis comprising 6,945 proteins separated these four groups, placing B cells of aged-matched controls between those of young donors and B-CLL patients, while identifying JVM-13 as poorly related cells. Mass spectrometric proteomics data have been made fully accessible via ProteomeXchange with identifier PXD006570-PXD006572, PXD006576, PXD006578, and PXD006589-PXD006591. Remarkably, B cells from aged controls displayed significant regulation of proteins related to stress management in mitochondria and ROS stress such as DLAT, FIS1, and NDUFAB1, and DNA repair, including RAD9A, MGMT, and XPA. ROS levels were indeed found significantly increased in B cells but not in T cells or monocytes from aged individuals. These alterations may be relevant for tumorigenesis and were observed similarly in B-CLL cells. In B-CLL cells, some remarkable unique features like the loss of tumor suppressor molecules PNN and JARID2, the stress-related serotonin transporter SLC6A4, and high expression of ZNF207, CCDC88A, PIGR and ID3, otherwise associated with stem cell phenotype, were determined. Alterations of metabolic enzymes were another outstanding feature in comparison to normal B cells, indicating increased beta-oxidation of fatty acids and increased consumption of glutamine. Targeted metabolomics assays corroborated these results. The present findings identify a potential proteome signature for immune senescence in addition to previously unrecognized features of B-CLL cells and suggest that aging may be accompanied by cellular reprogramming functionally relevant for predisposing B cells to transform to B-CLL cells.

Leukaemogenesis requires enhanced self-renewal, which is induced by oncogenes. The underlying molecular mechanisms remain incompletely understood. Here, we identified C/D box snoRNAs and rRNA 2′-O-methylation as critical determinants of leukaemic stem cell activity. Leukaemogenesis by AML1-ETO required expression of the groucho-related amino-terminal enhancer of split (AES). AES functioned by inducing snoRNA/RNP formation via interaction with the RNA helicase DDX21. Similarly, global loss of C/D box snoRNAs with concomitant loss of rRNA 2′-O-methylation resulted in decreased leukaemia self-renewal potential. Genomic deletion of either C/D box snoRNA SNORD14D or SNORD35A suppressed clonogenic potential of leukaemia cells in vitro and delayed leukaemogenesis in vivo. We further showed that AML1-ETO9a, MYC and MLL-AF9 all enhanced snoRNA formation. Expression levels of C/D box snoRNAs in AML patients correlated closely with in vivo frequency of leukaemic stem cells. Collectively, these findings indicate that induction of C/D box snoRNA/RNP function constitutes an important pathway in leukaemogenesis.

Pathophysiologies of cancer-associated syndromes such as cachexia are poorly understood and no routine biomarkers have been established, yet. Using shotgun proteomics, known marker molecules including PMEL, CRP, SAA, and CSPG4 were found deregulated in patients with metastatic melanoma. Targeted analysis of 58 selected proteins with multiple reaction monitoring was applied for independent data verification. In three patients, two of which suffered from cachexia, a tissue damage signature was determined, consisting of nine proteins, PLTP, CD14, TIMP1, S10A8, S10A9, GP1BA, PTPRJ, CD44, and C4A, as well as increased levels of glycine and asparagine, and decreased levels of polyunsaturated phosphatidylcholine concentrations, as determined by targeted metabolomics. Remarkably, these molecules are known to be involved in key processes of cancer cachexia. Based on these results, we propose a model how metastatic melanoma may lead to reprogramming of organ functions via formation of platelet activating factors from long-chain polyunsaturated phosphatidylcholines under oxidative conditions and via systemic induction of intracellular calcium mobilization. Calcium mobilization in platelets was demonstrated to alter levels of several of these marker molecules. Additionally, platelets from melanoma patients proved to be in a rather exhausted state, and platelet-derived eicosanoids implicated in tumor growth were found massively increased in blood from three melanoma patients. Platelets were thus identified as important source of serum protein and lipid alterations in late stage melanoma patients. As a result, the proposed model describes the crosstalk between lipolysis of fat tissue and muscle wasting mediated by oxidative stress, resulting in the metabolic deregulations characteristic for cachexia.

Byline: W.-B. Winkler, R. Karnik, J. Slany Author Affiliation: Department of Internal Medicine II Krankenanstalt Rudolfstiftung A-1030 Wien, Austria

Mixed lineage leukemia caused by MLL fusion proteins is still a mostly incurable disease. Research on novel treatment strategies has gained momentum in the last years with the elucidation of the molecular mechanisms underlying the transforming potential of these powerful oncoproteins. This review summarizes the recent developments in this area including new attempts to treat MLL in a rational way by exploiting the biochemical vulnerabilities of the leukemogenic process.

The consumption of fruits and vegetables is increasing worldwide because of the positive impact of these foods on human health. Ready-to-eat, raw whole, and frozen fruits and vegetables were purchased from markets and examined for the presence of nontuberculous mycobacteria (NTM) using culture, real-time PCR (qPCR), and sequencing. Using qPCR, Mycobacteriumsp. at 100to 104ge/g (genome equivalents per gram) was found in almost all of the 178 samples; members of the M. aviumcomplex were found only sporadically. Culture and sequencing revealed the presence of 22 viable NTM isolates in 17 samples. In addition to NTM commonly found in the environment, several rarely described isolates of viable NTM were recovered. The presence of Mycobacterium shigaense, which has been previously isolated only from human patients, was found in lettuce, the first time that this species has been found in an environmental sample. Mycobacterium parmense, Mycobacterium palustre, and Mycobacterium llatzerense, which have been previously isolated from human patients and occasionally from soil and water, were recovered from leafy green vegetables. Strawberries and cut salad mixes contained Mycobacterium algericum, Mycobacterium fallax, and Mycobacterium minnesotense. NTM are primarily nonpathogenic. However, consumption of fruits or vegetables contaminated with NTM could represent a health risk for immunocompromised people, children, and the elderly.

In order to systematically analyze proteins fulfilling effector functionalities during inflammation, here we present a comprehensive proteome study of inflammatory activated primary human endothelial cells and fibroblasts. Cells were stimulated with interleukin 1-β and fractionated in order to obtain secreted, cytoplasmic and nuclear protein fractions. Proteins were submitted to a data-dependent bottom up analytical platform using a QExactive orbitrap and the MaxQuant software for protein identification and label-free quantification. Results were further combined with similarly generated data previously obtained from the analysis of inflammatory activated peripheral blood mononuclear cells. Applying a false discovery rate of less than 0.01 at both, peptide and protein level, a total of 8370 protein groups assembled from 117,599 peptides was identified; mass spectrometry data have been made fully accessible via ProteomeXchange with identifier PXD003406 to PXD003417.Comparative proteome analysis allowed us to determine common and cell type-specific inflammation signatures comprising novel candidate marker molecules and related expression patterns of transcription factors. Cardinal features of inflammation such as interleukin 1-β processing and the interferon response differed substantially between the investigated cells. Furthermore, cells also exerted similar inflammation-related tasks; however, by making use of different sets of proteins. Hallmarks of inflammation thus emerged, including angiogenesis, extracellular matrix reorganization, adaptive and innate immune responses, oxidative stress response, cell proliferation and differentiation, cell adhesion and migration in addition to monosaccharide metabolic processes, representing both, common and cell type-specific responsibilities of cells during inflammation.

MLL fusions are leukemogenic transcription factors that enhance transcriptional elongation through modification of chromatin and RNA Pol II. Global transcription rates and chromatin changes accompanying the transformation process induced by MLL-ENL were monitored by nascent RNA-seq and ChIP-seq, revealing 165 direct target genes separated into two distinct clades. ME5 genes bound MLL-ENL at the promoter, relied on DOT1L-mediated histone methylation, and coded preferentially for transcription factors, including many homeobox genes. A distinct ME3 group accumulated MLL-ENL beyond the termination site, was dependent on P-TEFb-mediated phosphorylation of RNA Pol II for transcription, and translated mainly into proteins involved in RNA biology and ribosome assembly. This dichotomy was reflected by a differential sensitivity toward small molecule inhibitors, suggesting the possibility of a combinatorial strategy for treatment of MLL-induced leukemia.

Inflammation is a physiological process involved in many diseases. Monitoring proteins involved in regulatory effects may help to improve our understanding of inflammation. We have analyzed proteome alterations induced in peripheral blood mononuclear cells (PBMCs) upon inflammatory activation in great detail using high-resolution mass spectrometry. Moreover, the activated cells were treated with dexamethasone to investigate their response to this antiphlogistic drug. From a total of 6886 identified proteins, 469 proteins were significantly regulated upon inflammatory activation. Data are available via ProteomeXchange with identifiers PXD001415–23. Most of these proteins were counter-regulated by dexamethasone, with some exceptions concerning members of the interferon-induced protein family. To confirm some of these results, we performed targeted MRM analyses of selected peptides. The inflammation-induced upregulation of proteins such as IL-1β, IL-6, CXCL2, and GROα was confirmed, however, with strong quantitative interindividual differences. Furthermore, the inability of dexamethasone to downregulate inflammation-induced proteins such as PTX3 and TSG6 was clearly demonstrated. In conclusion, the relation of cell function as well as drug-induced modulation thereof was successfully mapped to proteomes, suggesting targeted analysis as a novel and powerful drug evaluation method. Although most consequences of dexamethasone were found to be compatible with the expected mode of action, some unexpected but significant observations may be related to adverse effects.

Breast cancer is still the most common type of cancer in women; an important role in carcinogenesis is actually attributed to cancer-associated fibroblasts. In this study, we investigated whether it is possible to assess the functional state of cancer-associated fibroblasts through tumor tissue proteome profiling. Tissue proteomics was performed on tumor-central, tumor-near, and tumor-distant biopsy sections from breast adenocarcinoma patients, which allowed us to identify 2074 proteins. Data were interpreted referring to reference proteome profiles generated from primary human mammary fibroblasts comprising 4095 proteins. These cells were analyzed in quiescent cell state as well as after in vitro treatment with TGFβ or IL-1β, stimulating wound healing or inflammatory processes, respectively. Representative for cancer cells, we investigated the mammary carcinoma cell line ZR-75-1, identifying 5212 proteins. All mass analysis data have been made fully accessible via ProteomeXchange, DOI PXD001311 and PXD001323-8. Comparison of tissue proteomics data with all of those reference profiles revealed predominance of cancer cell-derived proteins within the tumor and fibroblast-derived proteins in the tumor-distant tissue sections. Remarkably, proteins characteristic for acute inflammation were hardly identified in the tissue samples. In contrast, several proteins found by us to be induced by TGFβ in mammary fibroblasts, including fibulin-5, SLC2A1, and MUC18, were positively identified in all tissue samples, with relatively higher abundance in tumor neighboring tissue sections. These findings indicate a predominance of cancer-associated fibroblasts with wound healing activities localized around tumors.

The pathogenesis of multiple myeloma (MM) is regarded as a multistep process, in which an asymptomatic stage of monoclonal gammopathy of undetermined significance (MGUS) precedes virtually all cases of MM. Molecular events characteristic for the transition from MGUS to MM are still poorly defined. We hypothesized that fibroblast-like cells in the tumor microenvironment are critically involved in the pathogenesis of MM. Therefore, we performed a comparative proteome profiling study, analyzing primary human fibroblast-like cells isolated from the bone marrow of MM, of MGUS, as well as of non-neoplastic control patients. Thereby, a group of extracellular matrix (ECM) proteins, ECM receptors, and ECM-modulating enzymes turned out to be progressively up-regulated in MGUS and MM. These proteins include laminin α4, lysyl-hydroxylase 2, prolyl 4-hydroxylase 1, nidogen-2, integrin α5β5, c-type mannose receptor 2, PAI-1, basigin, and MMP-2, in addition to PDGF-receptor β and the growth factor periostin, which are likewise involved in ECM activities. Our results indicate that ECM remodeling by fibroblast-like cells may take place already at the level of MGUS and may become even more pronounced in MM. The identified proteins which indicate the stepwise progression from MGUS to MM may offer new tools for therapeutic strategies.

AbstractNontuberculous mycobacteria (NTM) are potentially pathogenic agents commonly found in natural ecosystems, while food is considered to be another source of NTM for humans. We investigated a total of 92 tissue samples of freshwater fish and fish products: fish directly obtained from ponds (n=25), retail fresh (n=23) and frozen fish (n=23) and smoked fish products (n=21). Culture examination for the presence of mycobacteria was positive in 11 (11.9%) from all the examined samples. The 15 obtained isolates were identified as Mycobacterium fortuitum(n=5), M. immunogenum(n=2), M. phocaicum/ mucogenicum(n=1), M. neoaurum(n=2), M. peregrinum(n=2), M. porcinum(n=1) and M. senegalense/houstonense/conceptionense(n=2). NTM DNA was found in one (4.0%) sample of fresh fish from ponds and in 60.9% and 91.3% of retail fresh and frozen fish, respectively. None of the smoked fish products contained NTM DNA. The results of our study suggest that freshwater fish and fish products, especially retail frozen fish, might be a reservoir of NTM for humans, and proper handling and treatment before consumption of such products is recommended.

Stimulation of transcriptional elongation is a key activity of leukemogenic MLL fusion proteins. Here, we provide evidence that MLL-ENL also inhibits Polycomb-mediated silencing as a prerequisite for efficient transformation. Biochemical studies identified ENL as a scaffold that contacted the elongation machinery as well as the Polycomb repressive complex 1 (PRC1) component CBX8. These interactions were mutually exclusive in vitro, corresponding to an antagonistic behavior of MLL-ENL and CBX8 in vivo. CBX8 inhibited elongation in a specific reporter assay, and this effect was neutralized by direct association with ENL. Correspondingly, CBX8-binding-defective MLL-ENL could not fully activate gene loci necessary for transformation. Finally, we demonstrate dimerization of MLL-ENL as a neomorphic activity that may augment Polycomb inhibition and transformation.

HOX proteins are widely involved in hematopoietic development. These transcription factors combine a conserved DNA-binding homeobox with a divergent N-terminus that mediates interaction with variable cofactors. The resulting combinatorial diversity is thought to be responsible for mammalian HOX specificity. Contrasting this proposed mechanism for normal HOX function, here we demonstrate that, in the context of hematopoietic immortalization and leukemogenesis, individual HOX properties are governed almost exclusively by the homeodomain. Swap experiments between HOXA1 and HOXA9, 2 members of nonrelated paralog groups, revealed that gene expression patterns of HOX transformed cells in vitro are determined by the nature of the homeodomain. Similar results were seen in vivo during HOX-mediated leukemogenesis. An exchange of the homeodomains was sufficient to convert the slow, low-penetrance phenotype of HOXA1-induced leukemia to the aggressive fast-acting disease elicited by HOXA9 and vice versa. Mutation and deletion studies identified several subregions within the DNA binding domain responsible for paralog specificity. Previously defined binding sites for PBX cofactors within the exchangeable, nonhomeobox segment were dispensable for in vitro oncogenic HOX activity but affected in vivo disease development. The transcriptional activator domain shared by HOXA1 and HOXA9 at the very N-terminus proved essential for all transformation.

ABSTRACTThe present study was performed to assess the interlaboratory reproducibility of the molecular detection and identification of species of Zygomycetesfrom formalin-fixed paraffin-embedded kidney and brain tissues obtained from experimentally infected mice. Animals were infected with one of five species (Rhizopus oryzae, Rhizopus microsporus, Lichtheimia corymbifera, Rhizomucor pusillus, and Mucor circinelloides). Samples with 1, 10, or 30 slide cuts of the tissues were prepared from each paraffin block, the sample identities were blinded for analysis, and the samples were mailed to each of seven laboratories for the assessment of sensitivity. A protocol describing the extraction method and the PCR amplification procedure was provided. The internal transcribed spacer 1 (ITS1) region was amplified by PCR with the fungal universal primers ITS1 and ITS2 and sequenced. As negative results were obtained for 93% of the tissue specimens infected by M. circinelloides, the data for this species were excluded from the analysis. Positive PCR results were obtained for 93% (52/56), 89% (50/56), and 27% (15/56) of the samples with 30, 10, and 1 slide cuts, respectively. There were minor differences, depending on the organ tissue, fungal species, and laboratory. Correct species identification was possible for 100% (30 cuts), 98% (10 cuts), and 93% (1 cut) of the cases. With the protocol used in the present study, the interlaboratory reproducibility of ITS sequencing for the identification of major Zygomycetesspecies from formalin-fixed paraffin-embedded tissues can reach 100%, when enough material is available.

HOX homeobox genes are important regulators of normal and malignant hematopoiesis. Abdominal-type HOXA genes like HOXA9 are highly leukemogenic. However, little is known about transformation by anterior HOXA genes. Here we performed a comprehensive assessment of the oncogenic potential of every HOXA gene in primary hematopoietic cells. With exception of HOXA2 and HOXA5, all HOXA genes caused a block or delay of hematopoietic differentiation and cooperated with Meis1. No evidence for the alleged tumor-suppressor function of HOXA5 could be found. Whereas all active HOXA genes immortalized mixed granulocytic/monocytic populations, HOXA13 preferentially specified monocytoid development. The anterior HOXA genes HOXA1, HOXA4, and HOXA6 transformed cells, generating permanent cell lines, although they did so less potently than HOXA9. Upon transplantation these lines induced myeloproliferation and acute myeloid leukemia in recipient animals. Kinetic studies with inducible HOX derivatives demonstrated that anterior HOXA genes autonomously contributed to cellular transformation. This function was not mediated by endogenous Hoxa9, which was persistently expressed in cells transformed by anterior HOX genes. In summary our results demonstrate a hitherto unexpected role of anterior HOXA genes in hematopoietic malignancy.

HOXhomeobox genes are important regulators of normal and malignant hematopoiesis. Abdominal-type HOXAgenes like HOXA9are highly leukemogenic. However, little is known about transformation by anterior HOXAgenes. Here we performed a comprehensive assessment of the oncogenic potential of every HOXAgene in primary hematopoietic cells. With exception of HOXA2and HOXA5, all HOXAgenes caused a block or delay of hematopoietic differentiation and cooperated with Meis1. No evidence for the alleged tumor-suppressor function of HOXA5could be found. Whereas all active HOXAgenes immortalized mixed granulocytic/monocytic populations, HOXA13preferentially specified monocytoid development. The anterior HOXAgenes HOXA1, HOXA4, and HOXA6transformed cells, generating permanent cell lines, although they did so less potently than HOXA9. Upon transplantation these lines induced myeloproliferation and acute myeloid leukemia in recipient animals. Kinetic studies with inducible HOXderivatives demonstrated that anterior HOXAgenes autonomously contributed to cellular transformation. This function was not mediated by endogenous Hoxa9, which was persistently expressed in cells transformed by anterior HOXgenes. In summary our results demonstrate a hitherto unexpected role of anterior HOXAgenes in hematopoietic malignancy.

Acute myelogenous leukemia is driven by leukemic stem cells (LSCs) generated by mutations that confer (or maintain) self-renewal potential coupled to an aberrant differentiation program. Using retroviral mutagenesis, we identified genes that generate LSCs in collaboration with genetic disruption of the gene encoding interferon response factor 8 (Irf8), which induces a myeloproliferation in vivo. Among the targeted genes, we identified Mef2c, encoding a MCM1-agamous-deficiens-serum response factor transcription factor, and confirmed that overexpression induced a myelomonocytic leukemia in cooperation with Irf8 deficiency. Strikingly, several of the genes identified in our screen have been reported to be up-regulated in the mixed-lineage leukemia (MLL) subtype. High MEF2C expression levels were confirmed in acute myelogenous leukemia patient samples with MLL gene disruptions, prompting an investigation of the causal interplay. Using a conditional mouse strain, we demonstrated that Mef2c deficiency does not impair the establishment or maintenance of LSCs generated in vitro by MLL/ENL fusion proteins; however, its loss led to compromised homing and invasiveness of the tumor cells. Mef2c-dependent targets included several genes encoding matrix metalloproteinases and chemokine ligands and receptors, providing a mechanistic link to increased homing and motility. Thus, MEF2C up-regulation may be responsible for the aggressive nature of this leukemia subtype.

Chimeric proteins joining the histone methyltransferase MLL with various fusion partners trigger distinctive lymphoid and myeloid leukemias. Here, we immunopurified proteins associated with ENL, a protein commonly fused to MLL. Identification of these ENL-associated proteins (EAPs) by mass spectrometry revealed enzymes with a known role in transcriptional elongation (RNA polymerase II C-terminal domain kinase [RNAPolII CTD] positive transcription elongation factor b [pTEFb]), and in chromatin modification (histone-H3 methyltransferase DOT1L) as well as other frequent MLL partners (AF4, AF5q31, and LAF4), and polycomb group members (RING1, CBX8, and BCoR). The composition of EAP was further verified by coimmunoprecipitation, 2-hybrid analysis, pull-down, and colocalization experiments. Purified EAP showed a histone H3 lysine 79–specific methylase activity, displayed a robust RNAPolII CTD kinase function, and counteracted the effect of the pTEFb inhibitor 5,6-dichloro-benzimidazole-riboside. In vivo, an ENL knock-down diminished genome-wide as well as gene-specific H3K79 dimethylation, reduced global run-on elongation, and inhibited transient transcriptional reporter activity. According to structure-function data, DOT1L recruitment was important for transformation by the MLL-ENL fusion derivative. These results suggest a function of ENL in histone modification and transcriptional elongation.

Purpose: To report a complication of stent placement at a bifurcation in the infrapopliteal arteries.Case Report: A 60-year-old man presented with a complex subtotal stenosis in the anterior tibial artery and the tibioperoneal trunk. Two drug-eluting stents were implanted by means of the crush technique, successfully recanalizing the trifurcation. One week later, the patient was readmitted with a thrombotic occlusion of the popliteal artery. Fluoroscopy showed a fracture of the larger stent in the tibioperoneal trunk. After successful local thrombolysis, a stent fragment was located in the popliteal artery and removed with an Amplatz snare. Long-term follow-up was uneventful.Conclusion: Fracture may be a more common complication of bifurcation stenting when undertaken in a territory at high risk for this complication.

Abdominal-type HoxA genes in combination with Meis1 are well-documented on-cogenes in various leukemias but it is unclear how they exert their transforming function. Here we used a system of conditional transformation by an inducible mixed lineage leukemia-eleven-nineteen leukemia (MLL-ENL) oncoprotein to overexpress Hoxa9 and Meis1 in primary hematopoietic cells. Arrays identified c-Myb and a c-Myb target (Gstm1) among the genes with the strongest response to Hoxa9/Meis1. c-Myb overexpression was verified by Northern blot and quantitative reverse transcription-polymerase chain reaction (RT-PCR). Also MLL-ENL activated c-Myb through up-regulation of Hoxa9 and Meis1. Consequently, short-term suppression of c-Myb by small inhibitory RNA (siRNA) efficiently inhibited transformation by MLL-ENL but did not impair transformation by transcription factor E2A-hepatic leukemia factor (E2A-HLF). The anti c-Myb siRNA effect was abrogated by coexpression of a c-Myb derivative with a mutated siRNA target site. The introduction of a dominant-negative c-Myb mutant had a similar but weaker effect on MLL-ENL-mediated transformation. Hematopoietic precursors from mice homozygous for a hypo-morphic c-Myb allele were more severely affected and could be transformed neither by MLL-ENL nor by E2A-HLF. Ectopic expression of c-Myb induced a differentiation block but c-Myb alone was not transforming in a replating assay similar to Hoxa9/Meis1. These results suggest that c-Myb is essential but not sufficient for Hoxa9/Meis1 mediated transformation. (Blood. 2006;108:297-304)

Abdominal-type HoxAgenes in combination with Meis1are well-documented on-cogenes in various leukemias but it is unclear how they exert their transforming function. Here we used a system of conditional transformation by an inducible mixed lineage leukemia-eleven-nineteen leukemia (MLL-ENL) oncoprotein to overexpress Hoxa9and Meis1in primary hematopoietic cells. Arrays identified c-Myband a c-Mybtarget (Gstm1) among the genes with the strongest response to Hoxa9/Meis1. c-Myboverexpression was verified by Northern blot and quantitative reverse transcription-polymerase chain reaction (RT-PCR). Also MLL-ENL activated c-Mybthrough up-regulation of Hoxa9and Meis1. Consequently, short-term suppression of c-Mybby small inhibitory RNA (siRNA) efficiently inhibited transformation by MLL-ENL but did not impair transformation by transcription factor E2A-hepatic leukemia factor (E2A-HLF). The anti c-MybsiRNA effect was abrogated by coexpression of a c-Mybderivative with a mutated siRNA target site. The introduction of a dominant-negative c-Mybmutant had a similar but weaker effect on MLL-ENL-mediated transformation. Hematopoietic precursors from mice homozygous for a hypo-morphic c-Myballele were more severely affected and could be transformed neither by MLL-ENL nor by E2A-HLF. Ectopic expression of c-Mybinduced a differentiation block but c-Mybalone was not transforming in a replating assay similar to Hoxa9/Meis1. These results suggest that c-Mybis essential but not sufficient for Hoxa9/Meis1 mediated transformation. (Blood. 2006;108:297-304)

Network design problems, such as generalizations of the Steiner Tree Problem, can be cast as edge-cost-flow problems. An edge-cost flow problem is a min-cost flow problem in which the cost of the flow equals the sum of the costs of the edges carrying positive flow.We prove a hardness result for the Minimum Edge Cost Flow Problem (MECF). Using the one-round two-prover scenario, we prove that MECF does not admit a 2log1-ɛ n-ratio approximation, for every constant ɛ > 0, unless NP ⊆ DTIME(npolylogn).A restricted version of MECF, called Infinite Capacity MECF (ICF), is defined. The ICF problem is defined as follows: (i) all edges have infinite capacity, (ii) there are multiple sources and sinks, where flow can be delivered from every source to every sink, (iii) each source and sink has a supply amount and demand amount, respectively, and (iv) the required total flow is given as part of the input. The goal is to find a minimum edge-cost flow that meets the required total flow while obeying the demands of the sinks and the supplies of the sources. This problem naturally arises in practical scheduling applications, and is equivalent to the special case of single source MECF, with all edges not touching the source or the sink having infinite capacity.The directed ICF generalizes the Covering Steiner Problem in directed and undirected graphs. The undirected version of ICF generalizes several network design problems, such as: Steiner Tree Problem, k-MST, Point-to-point Connection Problem, and the generalized Steiner Tree Problem.An O(log x)-approximation algorithm for undirected ICF is presented. We also present a bi-criteria approximation algorithm for directed ICF. The algorithm for directed ICF finds a flow that delivers half the required flow at a cost that is at most O(nɛ/ɛ4) times bigger than the cost of an optimal flow. The running time of the algorithm is O(x2/ɛ ċ n1+1/ɛ), where x denotes the required total flow.Randomized approximation algorithms for the Covering Steiner Problem in directed and undirected graphs are presented. The algorithms are based on a randomized reduction to a problem called 1/2-Group Steiner. In undirected graphs, the approximation ratio matches the approximation ratio of Konjevod et al. [2002]. However, our algorithm is much simpler. In directed graphs, the algorithm is the first nontrivial approximation algorithm for the Covering Steiner Problem. Deterministic algorithms are obtained by derandomization.

ABSTRACTSaccharomyces cerevisiaeYaf9p and the mammalian leukemia-associated protein ENL share a high degree of similarity. To investigate the biological function of Yaf9p, this protein was used to search for interacting proteins in a two-hybrid system. Here, we demonstrate that Yaf9p binds directly to Swc4p, the yeast homolog of the mammalian DNA-methyltransferase-associated protein 1. Yaf9p and Swc4p associate through C-terminal domains, and both proteins coprecipitate in vitro in pull-down experiments and in vivo by immunoprecipitation. In living cells, Swc4p is present in a megadalton protein complex that shows a fractionation behavior in gel filtration similar to that of Esa1p, the histone acetyltransferase of the NuA4 complex. Recruitment of Yaf9p to DNA leads to promoter-specific transcriptional activation that can be inhibited by dominant negative Swc4p lacking the Yaf9p binding domain. Interference with Swc4p function also increases sensitivity to the microtubule toxin benomyl, a trait that corresponds to the known phenotype of a yaf9-knockout strain. In summary, the results suggest that Yaf9p and Swc4p form a protein pair that has a role in chromatin modification with possible implications also for the function of their mammalian counterparts.

OBJECTIVE: Long-distance running results in considerable stress. Little evidence exists about the role of the atrial and brain natriuretic peptides, ANP and BNP, deriving from the myocardium. The aim of our study was to investigate the influence of running 42.195 km on changes in circulating natriuretic propeptides and adrenocortical steroids. DESIGN AND METHODS: We studied 17 male and 2 female runners (age: 28-62 Years) participating in a marathon. Blood samples were obtained before and immediately after the competition. proANP(1-98) and proANP(1-30) as well as Nt-proBNP(8-29) were determined by enzyme immunoassays. RESULTS: Runners finished the competition between 2 h 58 min and 4 h 25 min. We observed a more pronounced increase in proANP(1-98) (+58%) and proANP(1-30) (+99%, both P<0.001) compared with Nt-proBNP(8-29) (+6%; P=0.005). Increases in proANP(1-30) positively correlated with runners' age (r=0.53; P=0.02). We also observed a marked increase in cortisol (+73%) and especially in aldosterone (+431%, both P<0.001). CONCLUSIONS: Cardiac strain during long-distance running may explain the pronounced increase in proANP. Other explanations for the observed rise in plasma levels might be a change in the permeability of myocardial cells and an impaired clearance. A rise in adrenocortical steroids may compensate for the negative influence of ANP on natriuresis and blood pressure. Positive effects of ANP during a marathon could be the regulation of body temperature by influencing sweat glands as well as the stimulation of lipolysis compensating for the enormous energy demand.

Objectives: To evaluate 1) how many patients with atrial fibrillation (AF) and heart failure were discharged from Austrian hospitals with antithrombotic therapy, 2) if the presence of risk factors for stroke/embolism (age > 65 years, arterial hypertension, diabetes, and previous stroke) influence the choice of antithrombotic therapy and if the presence of contraindications for oral anticoagulation (dementia, alcohol abuse) influence the choice of antithrombotic therapy, and 3) if there are differences among the types of departments in the use of antithrombotic therapy. Patients: Included were 1566 patients (841 female, 725 male, mean age 76 years) with AF and heart failure. Methods: at discharge, a questionnaire was completed including risk factors, contraindications for antithrombotic therapy, and antithrombotic medication. Results: Oral anticoagulants (OAC) had 26 % of the cases, acetyl salicylic acid (ASA) 31 %, a combination of OAC and ASA 2 %, and no antithrombotic therapy 41 %. The risk factors age > 65 years, arterial hypertension, diabetes, and previous stroke did not influence the choice of antithrombotic therapy. Dementia but not alcohol abuse influenced the choice against OAC. The rate of OAC was higher in cardiological or cardiovascular rehabilitation clinics than in other departments. Conclusion: The results of this survey show that in medical practice the recommendations regarding antithrombotic therapy in atrial fibrillation are rarely considered, especially when additional risk factors are present. Fragestellung: Ziel unserer Erhebung war es, zu erfassen, 1. wie vielen Patienten mit Vorhofflimmern eine antithrombotische Therapie bei der Entlassung aus österreichischen Krankenhausabteilungen empfohlen wurde; 2. ob Schlaganfall-/Embolie-Risikofaktoren (Alter > 65 Jahre, arterielle Hypertonie, Diabetes mellitus und früherer Schlaganfall) und Kontraindikationen für orale Antikoagulanzien (Demenz, Alkoholabusus) die Wahl der antithrombotischen Therapie beeinflußten und 3. ob zwischen den Krankenhausabteilungen Unterschiede bei der Therapieempfehlung bestanden. Patienten: Eingeschlossen wurden 1566 Patienten (841 Frauen 725 Männer, mittleres Alter 76 Jahre) mit permanentem oder paroxysmalem Vorhofflimmern und Herzinsuffizienz. Methoden: Bei Entlassung aus dem Krankenhaus wurden Schlaganfall-/Embolie-Risikofaktoren, Kontraindikationen und die empfohlene antithrombotische Medikation erfaßt. Ergebnisse: Orale Antikoagulanzien wurden 26 %, Azetylsalizylsäure (ASS) 31 %, eine Kombination von oralen Antikoagulanzien mit ASS 2 % und keine antithrombotische Therapie 41 % der Patienten empfohlen. Das Vorliegen von Schlaganfall-/Embolie-Risikofaktoren beeinflußte nicht die Wahl der antithrombotischen Therapie. Das Vorhandensein von Demenz, nicht aber von Alkoholabusus, beeinflußte die Empfehlung der antithrombotischen Therapie. Aus kardiologischen oder Rehabilitationsabteilungen entlassenen Patienten wurden häufiger orale Antikoagulanzien empfohlen als denen, die aus anderen Krankenhausabteilungen entlassen wurden. Konklusion: Unsere Ergebnisse zeigen, daß in der medizinischen Praxis die Empfehlungen für eine antithrombotische Therapie bei Vorhofflimmern zu selten berücksichtigt werden, insbesondere wenn zusätzliche Schlaganfall-/Embolie-Risikofaktoren vorhanden sind.

The allosteric modulation of [ 3 H]flunitrazepam binding by γ-aminobutyric acid (GABA), pentobarbital, (+)-etomidate, etazolate, alphaxalone, propofol and chlormethiazole was investigated in cerebellar membranes from human embryonic kidney (HEK) 293 cells transfected with α 1 β 3 γ 2 or α 1 γ 2 subunits. Results obtained indicate that [ 3 H]flunitrazepam binding to recombinant GABA A receptors consisting of α 1 β 3 γ 2 subunits could be modulated by these compounds in a way and with a potency similar to that observed in cerebellar membranes. In addition, it was demonstrated that not only receptors consisting of α 1 β 3 γ 2 , but also those consisting of α 1 γ 2 subunits exhibited [ 3 H]flunitrazepam binding which could be stimulated by GABA. In contrast to α 1 β 3 γ 2 receptors, however, [ 3 H]flunitrazepam binding to recombinant α 1 γ 2 receptors was inhibited by pentobarbital, (+)-etomidate, etazolate, alphaxalone, propofol and chlormethiazole. This seems to indicate that binding sites for these compounds are present on α 1 γ 2 receptors, but that their allosteric interaction with [ 3 H]flunitrazepam binding sites is different from that of α 1 β 3 γ 2 receptors.

Specific endogenous [ 3 H]flunitrazepam binding sites were identified and characterized in membranes from the human embryonic kidney (HEK) cell line 293. A large part of these binding sites exhibited an intermediate affinity for [ 3 H]flunitrazepam and a μM affinity for diazepam, clonazepam, 1-(2- chlorophenyl )-N- methyl -N-(1- methylpropyl )-3- isoquinolinecarboxamide (PK 11195) or 4′-chlorodiazepam (Ro 5-4864). These sites, thus, resembled neither γ-aminobutyric acid A (GABA A ) receptor associated nor 'peripheral' benzodiazepine binding sites. A small part of the binding sites labeled by [ 3 H]flunitrazepam seemed to belong to 'peripheral' benzodiazepine binding sites exhibiting a nM affinity for PK 11195, and another small part of the binding sites seemed to exhibit a high affinity for flunitrazepam and PK 11195. Although small amounts of mRNA for α 1 -, β 3 - and γ 2 - subunits of GABA A receptors could be identified in HEK 293 cells, neither the actual expression of GABA A receptors in these cells nor a coassembly of endogenous subunits with transfected GABA A receptor subunits could be demonstrated by binding studies.

Objective: To assess the value of endoscopic guidance in bedside percutaneous dilational tracheostomy. Design: The medical critical care unit of a large community hospital. Setting: 71 consecutive adult patients who required prolonged mechanical ventilation. Interventions: 72 elective percutaneous dilational tracheostomies using the Ciaglia technique were performed under view of a flexible fiberoptic bronchoscope. Measurements and results: Patients were examined during tracheostomy and on days 2 and 7 after the procedure, at discharge and after half a year if they were still alive. A correct median puncture was observed by endoscopic control in 59 interventions. an initial paramedian puncture was detected in 13/72 (18%) procedures and was corrected by renewed insertion in all cases. No severe complications related to percutaneous dilational tracheostomy were noticed. Minor complications occurred in 4/71 (5.6%) patients including minor bleeding in 2, inflammatory infiltration in 1 and one superficial lesion of the posterior tracheal mucosa. Long-term follow-up revealed stomal granulation in 3 patients including one at the tracheal site. At the end of the observation period the tracheostomy still was in use in 14/71 (20%) patients and 12/71 (17%) patients were decannulated. Due to their severe underlying diseases 45/71 (63%) patients had died. To facilitate weaning from the tracheostomy a minitracheostomy tube was used in 3 patients. Conclusion: Percutaneous dilational tracheostomy is a simple bedside procedure associated with a low complication rate. We recommend the use of endoscopic guidance to increase the safety of tracheal puncture and dilation procedure.

Summary: The aim of this prospective study was to classify cardiac involvement in myopathies by means of a comprehensive cardiac investigation, to determine the rate of cardiac involvement in myopathies according to this classification and to compare the validity of previously reported electrocardiographic myopathy indices (QT/PQs, P/PQs, R/S) with that of the comprehensive cardiac investigation. We included 14 patients with myotonic dystrophy, 6 patients with Becker’s muscular dystrophy and 10 patients with mitochondrial myopathy. Cardiac involvement was classified as either “definite”, “equivocal” or “absent” by assessing cardiovascular history, physical examination, electrocardiography, echocardiography and 24-hour ambulatory electrocardiography. “Definite”/“equivocal”/“absent” cardiac involvement was found in 12/2/0 myotonic dystrophy, 3/3/0 Becker’s muscular dystrophy and 6/3/1 mitochondrial myopathy patients. Electrocardiographic myopathy indices were pathologic in 3 Becker’s muscular dystrophy, 6 mitochondrial myopathy but in none of the myotonic dystrophy patients. The proposed comprehensive cardiac investigation is simple, inexpensive and effective in assessing cardiac involvement in patients with myotonic dystrophy. Becker’s muscular dystrophy and mitochondrial myopathy. In case of cardiac involvement, cardiac therapy might be one of the few therapeutic options for these patients.

Cerebral ischemia is very rare in children and young adults. There can be a multitude of causes; in many cases etiology remains undetermined. We report here on 7 cases, 11 to 25 years of age. Pathogenetic factors (lupus erythematodes, endocarditis, fibromuscular dysplasia) and risk factors (cigarette smoking, oral contraceptives) were found in 5 patients whereas in 2 cases the etiology was not determinable. Three patients were treated with low weight dextrans, two patients received prostaglandin E1, and in 2 cases regional thrombolysis was performed. Three female patients died, two with occlusions of the rostral part of the basilar artery and one with an occlusion of the carotid artery and lupus erythematodes as the primary disease. Long-term observations of the surviving patients showed good recovery from neurological deficits. Prognosis quoad sanationem seems better in this age group than in elderly patients.