Thromboembolic events are common in patients with essential thrombocythemia (ET). However, the pathophysiological mechanisms underlying the increased thrombotic risk remain to be determined. Here, we perform the first phenotypical characterization of platelet expression using single-cell mass cytometry in six ET patients and six age- and sex-matched healthy individuals.
View Article and Find Full Text PDFBackground: Mutations in cKIT or PDGFRA are found in up to 90% of patients with gastrointestinal stromal tumors (GISTs). Previously, we described the design, validation, and clinical performance of a digital droplet (dd)PCR assay panel for the detection of imatinib-sensitive cKIT and PDFGRA mutations in circulating tumor (ct)DNA. In this study, we developed and validated a set of ddPCR assays for the detection of cKIT mutations mediating resistance to cKIT kinase inhibitors in ctDNA.
View Article and Find Full Text PDFPurpose: Hypereosinophilia represents a heterogenous group of severe medical conditions characterized by elevated numbers of eosinophil granulocytes in peripheral blood, bone marrow or tissue. Treatment options for hypereosinophilia remain limited despite recent approaches including IL-5-targeted monoclonal antibodies and tyrosine kinase inhibitors.
Methods: To understand aberrant survival patterns and options for pharmacologic intervention, we characterized BCL-2-regulated apoptosis signaling by testing for BCL-2 family expression levels as well as pharmacologic inhibition using primary patient samples from diverse subtypes of hypereosinophilia (hypereosinophilic syndrome n = 18, chronic eosinophilic leukemia not otherwise specified n = 9, lymphocyte-variant hypereosinophilia n = 2, myeloproliferative neoplasm with eosinophilia n = 2, eosinophilic granulomatosis with polyangiitis n = 11, reactive eosinophilia n = 3).
High-dose chemotherapy followed by autologous stem cell transplantation is a major component in the treatment of patients with multiple myeloma. As a prerequisite, the successful collection of a sufficient number of viable peripheral blood hematopoietic CD34+ cells is critical. A common standard protocol for mobilization is currently not defined and critically discussed especially in German-speaking Europe.
View Article and Find Full Text PDFJanus kinases (JAKs) mediate responses to cytokines, hormones and growth factors in haematopoietic cells. The JAK gene JAK2 is frequently mutated in the ageing haematopoietic system and in haematopoietic cancers. JAK2 mutations constitutively activate downstream signalling and are drivers of myeloproliferative neoplasm (MPN).
View Article and Find Full Text PDFAn amendment to this paper has been published and can be accessed via a link at the top of the paper.
View Article and Find Full Text PDFRecent clinical findings in patients with chronic myeloid leukemia (CML) suggest that the risk of molecular recurrence after stopping tyrosine kinase inhibitor (TKI) treatment substantially depends on an individual's leukemia-specific immune response. However, it is still not possible to prospectively identify patients that will remain in treatment-free remission (TFR). Here, we used an ordinary differential equation model for CML, which explicitly includes an antileukemic immunologic effect, and applied it to 21 patients with CML for whom time courses had been quantified before and after TKI cessation.
View Article and Find Full Text PDFIntroduction: Targeting the cell cycle machinery represents a rational therapeutic approach in myelodysplastic syndromes (MDS) and secondary acute myeloid leukemia (sAML). Despite substantial response rates, clinical use of the PLK inhibitor volasertib has been hampered by elevated side effects such as neutropenia and infections.
Objectives: The primary objective was to analyse whether a reduced dose of volasertib was able to limit toxic effects on the healthy haematopoiesis while retaining its therapeutic effect.
Patients with Myelodysplastic Syndromes (MDS) and secondary Acute Myeloid Leukemia (sAML) have a very poor prognosis after failure of hypomethylating agents (HMA). Stem cell transplantation is the only effective salvage therapy, for which only a limited number of patients are eligible due to age and comorbidity. Combination therapy of venetoclax and azacitidine (5-AZA) seems to be a promising approach in myeloid malignancies, but data from patients with HMA failure are lacking.
View Article and Find Full Text PDFThis prospective trial aimed to investigate whether tumor-specific cKIT and PDGFRA mutations can be detected and quantified in circulating tumor (ct)DNA in patients with active GIST, and whether detection indicates disease activity. We included 25 patients with active disease and cKIT or PDGFRA mutations detected in tissue. Mutant ctDNA was detected in the peripheral blood plasma using allele-specific ligation (L-)PCR and droplet digital (d)PCR.
View Article and Find Full Text PDFSomatic mutations in genes such as , , or adversely affect the outcome of patients with myelodysplastic syndromes (MDS). Since selective BCL-2 inhibition is a promising treatment strategy in hematologic malignancies, we tested the therapeutic impact of ABT-199 on MDS patient samples bearing an adverse mutational profile. By gene expression, we found that the level of pro-apoptotic BIM significantly decreased during MDS disease progression in line with an acquired resistance to cell death.
View Article and Find Full Text PDFSince acute myeloid leukemia (AML) is characterized by the blockade of hematopoietic differentiation and cell death, we interrogated RIPK3 signaling in AML development. Genetic loss of Ripk3 converted murine FLT3-ITD-driven myeloproliferation into an overt AML by enhancing the accumulation of leukemia-initiating cells (LIC). Failed inflammasome activation and cell death mediated by tumor necrosis factor receptor caused this accumulation of LIC exemplified by accelerated leukemia onset in Il1r1(-/-), Pycard(-/-), and Tnfr1/2(-/-) mice.
View Article and Find Full Text PDFBackground And Aim: In German-speaking countries, the physicians' roles framework of the "Canadian Medical Education Directives for Specialists" (CanMEDS) is increasingly used to conceptualize postgraduate medical education. It is however unclear, whether it may also be applied to the final year of undergraduate education within clinical clerkships, called "Practical Year" (PY). Therefore, the aim of this study was to explore how clinically active physicians at a university hospital and at associated teaching hospitals judge the relevance of the seven CanMEDS roles (and their (role-defining) key competencies) in respect to their clinical work and as learning content for PY training.
View Article and Find Full Text PDFDeregulated apoptosis is an identifying feature of myelodysplastic syndromes (MDS). Whereas apoptosis is increased in the bone marrow (BM) of low-risk MDS patients, progression to high-risk MDS correlates with an acquired resistance to apoptosis and an aberrant expression of BCL-2 proteins. To overcome the acquired apoptotic resistance in high-risk MDS, we investigated the induction of apoptosis by inhibition of pro-survival BCL-2 proteins using the BCL-2/-XL/-W inhibitor ABT-737 or the BCL-2-selective inhibitor ABT-199.
View Article and Find Full Text PDFThe immunomodulating capacity of the methylxanthine A802715 (5-hydroxy-5-methyl)hexyl-3-methyl-7-propylxanthin) was investigated in various murine models of endotoxemia and compared with that of the chemically related reference compound pentoxifylline. At a dose of 180 mg/kg both compounds protected mice against a lethal shock dose of lipopolysaccharide (LPS) (5 mg/kg) in nonsensitized mice and against LPS (5 micrograms/kg)-initiated liver failure in D-galactosamine (700 mg/kg)-sensitized animals. The methylxanthines attenuated systemic release of endogenous tumor necrosis factor (TNF) and interferon-gamma during endotoxic shock, and potently up-regulated early production of circulating interleukin-10 and interleukin-6.
View Article and Find Full Text PDFBackground & Aims: The injection of mice with anti-CD3 monoclonal antibody causes activation of T lymphocytes and leads to a lethal shock syndrome. The aim of this study was to investigate T cell-dependent, cytokine-mediated target cell death that leads to organ injury.
Methods: Anti-CD3 monoclonal antibody or staphylococcal enterotoxin B was injected into mice sensitized by D-galactosamine.
The systemic inflammatory response is characterized by release of circulating TNF which may cause multiorgan failure including septic liver failure. We studied TNF signaling in an appropriate in vitro system with primary murine hepatocyte cultures from normal and genetically altered animals. Either one of the three different TNF species, huTNF-alpha, huTNF-beta, or muTNF-alpha (at concentrations > 1 ng/ml) induced direct hepatocytotoxicity preceded by DNA fragmentation in cells prepared from wild-type C57BL mice.
View Article and Find Full Text PDFComparative sequence analyses were performed on 14 genes encoding bacterial elongation factors EF-Tu and 7 genes encoding the beta-subunit of bacterial F1F0 type ATP-synthases. The corresponding predicted amino acid sequences were compared with published primary structures of homologous molecules. Phylogenetic trees were reconstructed from both data sets of aligned protein sequences and from an equivalent selection of 16S rRNA sequences by applying distance matrix and maximum parsimony methods.
View Article and Find Full Text PDFZ Exp Chir Transplant Kunstliche Organe
May 1986
Well defined results can be obtained quickly by in vitro test concerning the preservation effect of the preserved dog's pancreas. Clinical and chemical parameters were received during the hypothermic perfusion respectively during the refrigerant storage. The in vitro function tests were carried out after the preservation by insulin and glucagon stimulation.
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