Amsacrine combined with etoposide and methylprednisolone is a feasible and safe component in first-line intensified treatment of pediatric patients with high-risk acute lymphoblastic leukemia in CoALL08-09 trial

BACKGROUND

The prognosis of children with acute lymphoblastic leukemia (ALL) has improved considerably over the past five decades. However, to achieve cure in patients with refractory or relapsed disease, novel treatment options are necessary.

METHODS

In the multicenter trial Cooperative Study Group for Childhood Acute Lymphoblastic Leukemia (CoALL)08-09, one additional treatment element consisting of the rarely used chemotherapeutic agent amsacrine combined with etoposide and methylprednisolone (AEP) (amsacrine 2 × 100 mg/m² , etoposide 2 × 500 mg/m² , and methylprednisolone 4 × 1000 mg/m² ) was incorporated into the first-line treatment of pediatric patients with poor treatment responses at the end of induction (EOI), measured by minimal residual disease (MRD). These patients were stratified into a high-risk intensified arm (HR-I), including an AEP element at the end of consolidation. Patients with induction failure (IF), that is, with lack of cytomorphological remission EOI, were eligible for hematopoietic stem cell transplantation (HSCT) after remission had been reached. These patients received AEP as a part of their MRD-guided bridging-to-transplant treatments.

RESULTS

A significant improvement in probability of overall survival (pOS) was noted for the CoALL08-09 HR-I patients compared to MRD-matched patients from the preceding CoALL07-03 trial in the absence of severe or persistent treatment-related toxicities. Relapse rate and probability of event-free survival (pEFS) did not differ significantly between trials. In patients with IF, stable or improved MRD responses after AEP were observed without severe or persistent treatment-related toxicities.

CONCLUSION

In conclusion, AEP is well tolerated as a component of the HR treatment and is useful in bridging-to-transplant settings.

Elucidation of the Translation Initiation Factor Interaction Network of Haloferax volcanii Reveals Coupling of Transcription and Translation in Haloarchaea

Translation is an important step in gene expression. Initiation of translation is rate-limiting, and it is phylogenetically more diverse than elongation or termination. Bacteria contain only three initiation factors. In stark contrast, eukaryotes contain more than 10 (subunits of) initiation factors (eIFs). The genomes of archaea contain many genes that are annotated to encode archaeal homologs of eukaryotic initiation factors (aIFs). However, experimental characterization of aIFs is scarce and mostly restricted to very few species. To broaden the view, the protein-protein interaction network of aIFs in the halophilic archaeon Haloferax volcanii has been characterized. To this end, tagged versions of 14 aIFs were overproduced, affinity isolated, and the co-isolated binding partners were identified by peptide mass fingerprinting and MS/MS analyses. The aIF-aIF interaction network was resolved, and it was found to contain two interaction hubs, (1) the universally conserved factor aIF5B, and (2) a protein that has been annotated as the enzyme ribose-1,5-bisphosphate isomerase, which we propose to rename to aIF2Bα. Affinity isolation of aIFs also led to the co-isolation of many ribosomal proteins, but also transcription factors and subunits of the RNA polymerase (Rpo). To analyze a possible coupling of transcription and translation, seven tagged Rpo subunits were overproduced, affinity isolated, and co-isolated proteins were identified. The Rpo interaction network contained many transcription factors, but also many ribosomal proteins as well as the initiation factors aIF5B and aIF2Bα. These results showed that transcription and translation are coupled in haloarchaea, like in Escherichia coli. It seems that aIF5B and aIF2Bα are not only interaction hubs in the translation initiation network, but also key players in the transcription-translation coupling.

Clofarabine increases the eradication of minimal residual disease of primary Bprecursor acute lymphoblastic leukemia compared to high-dose cytarabine without improvement of outcome

Novel treatment strategies are needed to improve cure for all children with acute lymphoblastic leukemia. To this end, we investigated the therapeutic potential of clofarabine in primary acute lymphoblastic leukemia in trial CoALL 08-09. The primary study objective was the minimal residual disease (MRD)-based comparative assessment of cytotoxic efficacies of clofarabine 5x40 mg/m2 versus high-dose cytarabine (HIDAC) 4x3g/m2, both in combination with PEG-ASP 2500 IU/m2 as randomized intervention in early consolidation. The secondary objective was an outcome analysis focused on treatment-arm dependence and MRD after randomized intervention. In B-cell precursor (BCP)-ALL, eradication of MRD was more profound after clofarabine compared to cytarabine, with 93 vs 79 of 143 randomized patients per arm reaching MRD-negativity (Chi-square test P=.03, left-sided P(Fisher's exact test)=.04). MRD status of BCP-ALL after randomized intervention maintained its prognostic relevance, with a significant impact on event-free survival (EFS) and relapse rate. However, no difference in outcome regarding EFS and overall survival (OS) between randomized courses was observed (5- year EFS: clofarabine 85.7, SE=4.1 vs HIDAC 84.8, SE=4.7 (P=.96); OS: 95.7, SE=1.9 vs 92.2, SE=3.2 (P=.59)), independent of covariates or overall risk strata. Severe toxicities between randomized and subsequent treatment elements were also without significant difference. In conclusion, clofarabine/PEG-ASP is effective and safe, but greater cytotoxic efficacy of clofarabine compared to HIDAC did not translate into improved outcomes indicating a lack of surrogacy of post-intervention MRD at the trial level as opposed to the patient level, which hampers a broader implementation of this regimen in the frontline treatment of ALL.

Daunorubicin during delayed intensification decreases the incidence of infectious complications - a randomized comparison in trial CoALL 08-09

Anthracyclines are integral components of antileukemic treatment. Apart from cardiotoxicity, myelosuppression and infectious complications have been described for doxorubicin (DOX) and daunorubicin (DNR) as predominant side effects, but little is known about their differential toxicities. To address the question whether DNR is associated with a lower rate of infectious complications compared with DOX, 307 children with newly diagnosed acute lymphoblastic leukemia, enrolled in trial CoALL 08-09, were randomized to receive either DOX 30 mg/m² (n = 153) or DNR 36 mg/m² (n = 154) in delayed intensification. Hematologic toxicities and stomatitis were less frequent in the DNR group resulting in a significantly lower rate of infections in the DNR arm (27% vs. 59%, p < .0001). Survival was equal in both arms (95% SE 2%) (p = .55), with an insignificant difference in the relapse rate (RR 0.12 (SE = 0.03) in the DOX arm vs. 0.16 (SE = 0.04) in the DNR arm; p = .37; Hazard ratio 1.3; 95% confidence interval 0.7-2.6). In conclusion, DNR given in delayed intensification is associated with a lower incidence of infectious complications without loss of efficacy.

Emergence and dissemination of a linezolid-resistant Staphylococcus capitis clone in Europe

Objectives

We investigated the epidemiological, clinical, microbiological and genetic characteristics of linezolid-resistant (LZR) Staphylococcus capitis isolates from French ICUs, and compared them with LZR S. capitis isolates from other European countries.

Methods

All LZR isolates were subjected to antimicrobial susceptibility testing (AST) and the presence of cfr and optrA genes as well as mutations in the 23S rRNA and ribosomal proteins were investigated using specific PCR with sequencing. The genetic relationship between isolates was investigated using PFGE and WGS. Epidemiological data concerning LZR S. capitis were collected retrospectively in French microbiology laboratories.

Results

Twenty-one LZR isolates were studied: 9 from France, 11 from Greece and 1 from Finland. All were resistant to methicillin and aminoglycosides. In addition, this unusual AST profile was identified in S. capitis isolates from seven French hospitals, and represented up to 12% of the S. capitis isolates in one centre. A G2576T mutation in 23S rRNA was identified in all isolates; cfr and optrA genes were absent. All isolates belonged to the same clone on the basis of their PFGE profiles, whatever their geographical origin. WGS found at most 212 SNPs between core genomes of the LZR isolates.

Conclusions

We identified and characterized an LZR S. capitis clone disseminated in three European countries, harbouring the same multiple resistance and a G2576T mutation in the 23S rRNA. The possible unrecognized wider distribution of this clone, belonging to a species classically regarded as a low-virulence skin colonizer, is of major concern not least because of the increasing use of oxazolidinones.

Cytotoxicity of carbon nanohorns in different human cells of the respiratory system

One of the new synthetic carbon-based nanomaterials is carbon nanohorns (CNH). A potential risk for employees of production processes is an unintentional intake of these nanomaterials via inhalation. Once taken up, nanoparticles might interact with cells of different tissues as well as with intercellular substances. These interactions may have far-reaching consequences for human health. Currently, many gaps in available information on the CNH toxicological profile remain. The aim of this study was to determine the cytotoxicity of CNH particles on human epithelial cells of the respiratory system with special consideration given to different particle sizes. In all cell lines, cell viability was reduced after 24 h of exposure up to 60% and metabolic activity as evidenced by mitochondrial activity was lowered to 9% at a concentration of 1 g/L. The three respiratory cell lines differed in their sensitivity. The most robust cells were the bronchial epithelial cells. Further, particle size fractions induced different adverse effect strength, whereby no correlation between particle size fraction and toxicity was found. These findings demonstrate the need for further information regarding the behavior and effect strength of nanomaterial. To avoid the production of new harmful materials, a more comprehensive integration of results from toxicity studies in the development processes of engineered nanomaterials is recommended not only from an occupational viewpoint but also from an environmental perspective.

Elektronischer Mutter(Eltern)-Kind Pass – Möglichkeiten, Zielsetzungen und internationale Erfahrungen

Vor dem Hintergrund einer Neugestaltung des Eltern-Kind-Vorsorgeprogramms in Österreich, welche auch eine elektronische statt papierbasierte Umsetzung beinhalten könnte, soll ein Überblick internationaler Pilotierungen elektronischer Eltern-Kind-Vorsorge Initiativen (eEKVI) gegeben, und für die Umsetzung relevanten Grenzen, Möglichkeiten und Zielsetzungen dieser Projekte aufgezeigt werden.

Datenbankrecherche sowie Handsuche nach internationalen (Pilot-) Projekten.

Von 30 ausgewählten eEKVI können 9 als elektronische Eltern- bzw. Kinder-Gesundheitsakten angesehen werden, welche entweder im Kontext einer umfassenden elektronischen Gesundheitsakte, als elektronische Umsetzung eines papierbasierten Dokuments oder als an eine Einrichtung gebundene IT-Lösung realisiert wurden. eEKVI sind bislang international noch kaum flächendeckend implementiert, einige wenige bedienen neben klassischen Kern-Zielen (Abwicklung und Administration der Versorgung usw.) auch planerische Zielsetzungen und ermöglichen dadurch ein systemisches Lernen aufgrund von Feedback und Evaluationszyklen.

Basierend auf Erfahrungen internationaler eEKVI sollten Kernaspekte einer erfolgreichen Planung und Umsetzung, wie beispielsweise die Definition von erwarteten Nutzen-Zielen und deren Monitoring oder die Bildung eines für Planung und Konzeption verantwortlichen Teams unter früher Einbeziehung von Endnutzern und Akteuren, berücksichtigt werden, um vermeidbare Fehler zu minimieren. Eine konsequente Technikfolgenabschätzung – auch von IT-basierten Interventionen im Gesundheitswesen – ist jedenfalls zu fordern, um ein reflektiertes Vorgehen zu ermöglichen.

Epoxide and thiirane toxicity in vitro with the ciliates Tetrahymena pyriformis: structural alerts indicating excess toxicity

The 48 h toxicity of 18 organic narcotics, 13 epoxides, and 2 thiiranes toward the ciliates Tetrahymena pyriformis was determined in terms of 50% growth inhibition EC(50). Nominal EC(50) was corrected for volatilization and sorption to quantify the freely dissolved compound fraction in solution. The derived baseline narcosis model served to evaluate toxicity enhancements T(e) as ratios of narcosis-predicted over experimental EC(50) values. Among the nine heterocycles with aliphatic side chains that include two thiiranes, three compounds yielded T(e) > 10, suggesting their covalent binding at nucleophilic protein sites such as -OH, -NHR, and -SH through S(N)2-type ring-opening. As a general trend of this group, T(e) decreases with increasing alkyl group size. Moreover, four of the six nonaliphatic epoxides exerted substantial excess toxicities with T(e) > 10, which could be rationalized by ring-opening activation through negative inductive effect, benzylic stabilization, and phenyl ring H-bonding. By contrast, 1,2 substituted epoxides showed narcosis-level toxicity, despite the opportunity of side-chain Schiff-base formation with protein amino groups. The resulting structural alerts enable an in silico screening of epoxides and thiiranes for their potential to exert excess toxicity. Note that observed differences in T(e) sensitivity between ciliates, bacteria and fish should be taken into account when designing in vitro alternatives to fish toxicity studies.

Fusion of a Short HA2-Derived Peptide Sequence to Cell-Penetrating Peptides Improves Cytosolic Uptake, but Enhances Cytotoxic Activity

Cell-penetrating peptides (CPP) have become a widely used tool for efficient cargo delivery into cells. However, one limiting fact is their uptake by endocytosis causing the enclosure of the CPP-cargo construct within endosomes. One often used method to enhance the outflow into the cytosol is the fusion of endosome-disruptive peptide or protein sequences to CPP. But, until now, no studies exist investigating the effects of the fusion peptide to the cellular distribution, structural arrangements and cytotoxic behaviour of the CPP. In this study, we attached a short modified sequence of hemagglutinin subunit HA2 to different CPP and analysed the biologic activity of the new designed peptides. Interestingly, we observed an increased cytosolic distribution but also highly toxic activities in the micromolar range against several cell lines. Structural analysis revealed that attachment of the fusion peptide had profound implications on the whole conformation of the peptide, which might be responsible for membrane interaction and endosome disruption.

[Study of hepatitis C virus leukotropism by characterization of viral quasispecies in the liver transplantation setting]

Besides hepatocytes, representing the main replication site of hepatitis C virus, peripheral blood mononuclear cells also represent a crucial target for viral infection. Hepatitis C virus compartmentalization (i.e., non-random distribution) of viral variants between plasma and peripheral blood mononuclear cells, more frequently observed in liver transplant patients compared to non-transplanted patients, makes liver transplantation an interesting model for the analysis of hepatitis C leukotropism. This article aims to present, firstly, in clinical and biological features arguing favour of hepatitis C virus infection leukotropism and, secondly, to review current knowledge about compartmentalization between plasma and peripheral blood mononuclear cells, especially in the liver transplantation setting.

A cascade of transcription factor DREB2A and heat stress transcription factor HsfA3 regulates the heat stress response of Arabidopsis

The dehydration-responsive element binding protein (DREB)/C-repeat binding factor (CBF) family are the classical transcriptional regulators involved in plant responses to drought, salt and cold stress. Recently it was demonstrated that DREB2A is induced by heat stress (hs) and is a regulator of the hs response of Arabidopsis. Here we provide molecular insights into the regulation and function of hs transcription factor HsfA3. Among the 21 members of the Arabidopsis Hsf family, HsfA3 is the only Hsf that is transcriptionally induced during hs by DREB2A, and HsfA3 in turn regulates the expression of Hsp-encoding genes. This transcription factor cascade was reconstructed in transient GUS reporter assays in mesophyll protoplasts by showing that DREB2A could activate the HsfA3 promoter, whereas HsfA3 in turn was shown to be a potent activator on the promoters of Hsp genes. Direct binding to the corresponding promoters was demonstrated by electrophoretic mobility shift assays, and the involvement of HsfA3 in the hs response in vivo was shown directly by observation of reduced thermotolerance in HsfA3 mutant lines. Altogether these data demonstrate that HsfA3 is transcriptionally controlled by DREB2A and important for the establishment of thermotolerance.

A cascade of transcription factor DREB2A and heat stress transcription factor HsfA3 regulates the heat stress response of Arabidopsis

The dehydration-responsive element binding protein (DREB)/C-repeat binding factor (CBF) family are the classical transcriptional regulators involved in plant responses to drought, salt and cold stress. Recently it was demonstrated that DREB2A is induced by heat stress (hs) and is a regulator of the hs response of Arabidopsis. Here we provide molecular insights into the regulation and function of hs transcription factor HsfA3. Among the 21 members of the Arabidopsis Hsf family, HsfA3 is the only Hsf that is transcriptionally induced during hs by DREB2A, and HsfA3 in turn regulates the expression of Hsp-encoding genes. This transcription factor cascade was reconstructed in transient GUS reporter assays in mesophyll protoplasts by showing that DREB2A could activate the HsfA3 promoter, whereas HsfA3 in turn was shown to be a potent activator on the promoters of Hsp genes. Direct binding to the corresponding promoters was demonstrated by electrophoretic mobility shift assays, and the involvement of HsfA3 in the hs response in vivo was shown directly by observation of reduced thermotolerance in HsfA3 mutant lines. Altogether these data demonstrate that HsfA3 is transcriptionally controlled by DREB2A and important for the establishment of thermotolerance.

Histamine mediates osteoclastic resorption only during the acute phase of bone loss in ovariectomized rats

Short-term studies have shown that histamine is involved, via its H2 receptors (H2R), in the mediator network regulating trabecular bone loss in long bones of ovariectomized (OVX) rats. It is not known whether this effect of histamine persists over time or involves other skeletal sites. In this study, rats were maintained for 6 months postOVX and treated daily with saline or famotidine (10 mg kg(-1)), an H2R antagonist. At the end of the experimental period, femur trabecular bone mass was markedly decreased in OVX rats, whether or not they were treated with famotidine. In contrast, in the fourth lumbar vertebra, where bone loss starts later than in the femur, famotidine treatment attenuated the decline in trabecular bone volume, protected the trabecular architecture, maintained the thickness of the cortices and reduced the numbers of osteoclasts and tartrate-resistant acid phosphatase-positive preosteoclasts, whereas it had no influence on bone formation parameters. In vertebral bone marrow of OVX rats, the numbers of mast cells (MCs) and non-MC histamine-producing cells increased, while famotidine treatment significantly diminished both cell populations. These data show that H2R antagonism does not protect trabecular bone mass in the long term, and that short-term protection involves all bones. Histamine is involved during the early phase of strong osteoclastic resorption but not during the late phase of slower resorption, suggesting that different mediator networks control the two phases of destruction. Histamine would be part of the network mediating the early phase.

The heat stress transcription factor HsfA2 serves as a regulatory amplifier of a subset of genes in the heat stress response in Arabidopsis

Within the Arabidopsis family of 21 heat stress transcription factors (Hsfs) HsfA2 is the strongest expressed member under heat stress (hs) conditions. Irrespective of the tissue, HsfA2 accumulates under heat stress similarly to other heat stress proteins (Hsps). A SALK T-DNA insertion line with a complete HsfA2-knockout was analyzed with respect to the changes in the transcriptome under heat stress conditions. Ascorbate peroxidase 2 (APX2) was identified as the most affected transcript in addition to several sHsps, individual members of the Hsp70 and Hsp100 family, as well as many transcripts of genes with yet unknown functions. For functional validation, the transcription activation potential of HsfA2 on GUS reporter constructs containing 1 kb upstream promoter sequences of selected target genes were analyzed using transient reporter assays in mesophyll protoplasts. By deletion analysis the promoter region of the strongest affected target gene APX2 was functionally mapped in detail to verify potential HsfA2 binding sites. By electrophoretic mobility shift assays we identified TATA-Box proximal clusters of heat stress elements (HSE) in the promoters of selected target genes as potential HsfA2 binding sites. The results presented here demonstrate that the expression of HsfA2 in Arabidopsis is strictly heat stress-dependent and this transcription factor represents a regulator of a subset of stress response genes in Arabidopsis.

Rechtliche Möglichkeiten und Grenzen der Integrierten Versorgung in der Kardiologie

Regulations of Integrated Health Care are capable of overriding the barriers of separated outpatient and inpatient health care. These regulations create a situation of competition among health care providers, but not among payers. Since the laws exclude common regulations of competition laws, antitrust laws and public procurement laws from Integrated Health Care, insurance companies gain a relatively strong position in the competition for contracts. This is even enforced by the fact that no health care provider is entitled to request a contract with a specific insurance company. The main result is that insurance companies can determine the contracts deliberately.