FRACTION: protocol of a phase II study of Fedratinib and Nivolumab combination in patients with myelofibrosis and resistance or suboptimal response to JAK-inhibitor treatment of the German MPN study group (GSG-MPN).

Development of Janus-kinase (JAK) inhibitors has revolutionized the therapeutic landscape for patients with myeloproliferative neoplasia (MPN). Following approval of the first JAK1/2-inhibitor Ruxolitinib, symptoms of this inflammatory disease, characterized by splenomegaly, release of inflammatory cytokines and appearance of thrombosis, could be effectively reduced for the first time. However, JAK-inhibitor treatment is limited in several aspects: 1) duration of response: 3 years after initiation of therapy more than 50% of patients have discontinued JAK-inhibitor treatment due to lack of efficacy or resistance; 2) reduction of disease burden: while effective in reducing inflammation and constitutional symptoms, JAK-inhibitors fail to reduce the malignant clone in the majority of patients and therefore lack long-term efficacy. Early clinical trials for patients with myelofibrosis (MF) have tried to address these issues for patients with suboptimal response to Ruxolitinib therapy while combination therapies with Fedratinib are rare. Recent reports provided first evidence on how the JAK2-V617F mutated myeloid cells may influence T-cell responses. JAK2-V617F promoted the synthesis of PD-L1 in MPN cells leading to limited anti-neoplastic T-cell responses, metabolic changes in T-cells and eventually JAK2-V617F-driven immune-escape of MPN cells. These findings may facilitate the use of immunotherapeutic approaches for JAK-mutated clones. Immune checkpoints refer to a variety of inhibitory pathways that are crucial for maintaining self-tolerance and modulating the duration and amplitude of physiological immune responses in peripheral tissues in order to minimize collateral tissue damage. The FRACTION study is a single arm, open label Phase II trial investigating the combination of Fedratinib with the PD-1 inhibitor Nivolumab in patients with myelofibrosis and suboptimal or lack of response to JAK-inhibitor therapy. Over a 12 months period the trial assesses longer term outcomes, particularly the effects on clinical outcomes, such as induction of clinical remissions, quality of life and improvement of anemia. No prospective clinical trial data exist for combinations of JAK- and immune-checkpoint-inhibitors in the planned MF study population and this study will provide new findings that may contribute to advancing the treatment landscape for MF patients with suboptimal responses and limited alternatives.

Oncogenic Calreticulin Induces Immune Escape by Stimulating TGF-ß Expression and Regulatory T Cell Expansion in the Bone Marrow Microenvironment.

Increasing evidence supports the interplay between oncogenic mutations and immune escape mechanisms. Strategies to counteract the immune escape mediated by oncogenic signaling could provide improved therapeutic options for patients with various malignancies. As mutant calreticulin (CALR) is a common driver of myeloproliferative neoplasms (MPN), we analyzed the impact of oncogenic CALRdel52 on the bone marrow (BM) microenvironment in MPN. Single-cell RNA-sequencing revealed that CALRdel52 led to the expansion of TGF-ß1-producing erythroid progenitor cells and promoted the expansion of FoxP3+ regulatory T cells (Treg) in a murine MPN model. Treatment with an anti-TGF-ß antibody improved mouse survival and increased the glycolytic activity in CD4+ and CD8+ T cells in vivo, while T cell depletion abrogated the protective effects conferred by neutralizing TGF-ß. TGF-ß1 reduced perforin and TNF-α production by T cells in vitro. TGF-ß1 production by CALRdel52 cells was dependent on JAK1/2, PI3K, and ERK activity, which activated the transcription factor Sp1 to induce TGF-ß1 expression. In four independent patient cohorts, TGF-ß1 expression was increased in the BM of MPN patients compared to healthy individuals, and the BM of MPN patients contained a higher frequency of Treg compared to healthy individuals. Together, this study identified an ERK/Sp1/TGF-ß1 axis in CALRdel52 MPNs as a mechanism of immunosuppression that can be targeted to elicit T-cell-mediated cytotoxicity.

Cystic vestibular schwannoma - a subgroup analysis from a comparative study between radiosurgery and microsurgery.

Some vestibular schwannoma (VS) show cystic morphology. It is known that these cystic VS bear different risk profiles compared to solid VS in surgical treatment. Still, there has not been a direct comparative study comparing both SRS and SURGERY effectiveness in cystic VS. This retrospective bi-center cohort study aims to analyze the management of cystic VS compared to solid VS in a dual center study with both microsurgery (SURGERY) and stereotactic radiosurgery (SRS). Cystic morphology was defined as presence of any T2-hyperintense and Gadolinium-contrast-negative cyst of any size in the pre-interventional MRI. A matched subgroup analysis was carried out by determining a subgroup of matched SURGERY-treated solid VS and SRS-treated solid VS. Functional status, and post-interventional tumor volume size was then compared. From 2005 to 2011, N = 901 patients with primary and solitary VS were treated in both study sites. Of these, 6% showed cystic morphology. The incidence of cystic VS increased with tumor size: 1.75% in Koos I, 4.07% in Koos II, 4.84% in Koos III, and the highest incidence with 15.43% in Koos IV. Shunt-Dependency was significantly more often in cystic VS compared to solid VS (p = 0.024) and patients with cystic VS presented with significantly worse Charlson Comorbidity Index (CCI) compared to solid VS (p < 0.001). The rate of GTR was 87% in cystic VS and therefore significantly lower, compared to 96% in solid VS (p = 0.037). The incidence of dynamic volume change (decrease and increase) after SRS was significantly more common in cystic VS compared to the matched solid VS (p = 0.042). The incidence of tumor progression with SRS in cystic VS was 25%. When comparing EOR in the SURGERY-treated cystic to solid VS, the rate for tumor recurrence was significantly lower in GTR with 4% compared to STR with 50% (p = 0.042). Tumor control in cystic VS is superior in SURGERY, when treated with a high extent of resection grade, compared to SRS. Therapeutic response of SRS was worse in cystic compared to solid VS. However, when cystic VS was treated surgically, the rate of GTR is lower compared to the overall, and solid VS cohort. The significantly higher number of patients with relevant post-operative facial palsy in cystic VS is accredited to the increased tumor size not its sole cystic morphology. Cystic VS should be surgically treated in specialized centers.

Predicting chronic wasting disease in white-tailed deer at the county scale using machine learning.

Continued spread of chronic wasting disease (CWD) through wild cervid herds negatively impacts populations, erodes wildlife conservation, drains resource dollars, and challenges wildlife management agencies. Risk factors for CWD have been investigated at state scales, but a regional model to predict locations of new infections can guide increasingly efficient surveillance efforts. We predicted CWD incidence by county using CWD surveillance data depicting white-tailed deer (Odocoileus virginianus) in 16 eastern and midwestern US states. We predicted the binary outcome of CWD-status using four machine learning models, utilized five-fold cross-validation and grid search to pinpoint the best model, then compared model predictions against the subsequent year of surveillance data. Cross validation revealed that the Light Boosting Gradient model was the most reliable predictor given the regional data. The predictive model could be helpful for surveillance planning. Predictions of false positives emphasize areas that warrant targeted CWD surveillance because of similar conditions with counties known to harbor CWD. However, disagreements in positives and negatives between the CWD Prediction Web App predictions and the on-the-ground surveillance data one year later underscore the need for state wildlife agency professionals to use a layered modeling approach to ensure robust surveillance planning. The CWD Prediction Web App is at https://cwd-predict.streamlit.app/ .

Hygienic evaluation of the Resourcify GmbH concept for recovering raw materials from recyclable medical devices after surgery.

In addition to emissions harmful to the environment, a significant amount of waste is generated in hospitals. In recognition of the fact that medical devices (MDs) contain valuable raw materials, such as rare earth elements, other metals, and high-quality plastics, a recycling concept has been developed. The project was examined for safety and feasibility from a hygiene point of view with sustainability in mind in order to create a reference solution for other areas as applicable. The recycling process begins when the MDs accumulate in the surgical facility and are separated into recyclable and disposable parts. The recyclable parts are subjected to wipe disinfection and collected in closed boxes until they are taken away, while the non-recyclable parts are sent for disposal. The recyclable waste, including the transport boxes, is steam-disinfected in a fractionated vacuum process before recycling. The waste is then recycled, and the emptied transport boxes are made available for re-collection by the surgical facility. The analysis of the overall recycling process shows that infectious risks both for the employees who collect, transport, and recycle the MDs and for the environment are neglectable.

Type I toxin-antitoxin systems in bacteria: from regulation to biological functions.

Toxin-antitoxin systems are ubiquitous in the prokaryotic world and widely distributed among chromosomes and mobile genetic elements. Several different toxin-antitoxin system types exist, but what they all have in common is that toxin activity is prevented by the cognate antitoxin. In type I toxin-antitoxin systems, toxin production is controlled by an RNA antitoxin and by structural features inherent to the toxin messenger RNA. Most type I toxins are small membrane proteins that display a variety of cellular effects. While originally discovered as modules that stabilize plasmids, chromosomal type I toxin-antitoxin systems may also stabilize prophages, or serve important functions upon certain stress conditions and contribute to population-wide survival strategies. Here, we will describe the intricate RNA-based regulation of type I toxin-antitoxin systems and discuss their potential biological functions.

No Benefit in Memory Performance after Nocturnal Memory Reactivation Coupled with Theta-tACS.

Targeted memory reactivation (TMR) is an effective technique to enhance sleep-associated memory consolidation. The successful reactivation of memories by external reminder cues is typically accompanied by an event-related increase in theta oscillations, preceding better memory recall after sleep. However, it remains unclear whether the increase in theta oscillations is a causal factor or an epiphenomenon of successful TMR. Here, we used transcranial alternating current stimulation (tACS) to examine the causal role of theta oscillations for TMR during non-rapid eye movement (non-REM) sleep. Thirty-seven healthy participants learned Dutch-German word pairs before sleep. During non-REM sleep, we applied either theta-tACS or control-tACS (23 Hz) in blocks (9 min) in a randomised order, according to a within-subject design. One group of participants received tACS coupled with TMR time-locked two seconds after the reminder cue (time-locked group). Another group received tACS in a continuous manner while TMR cues were presented (continuous group). Contrary to our predictions, we observed no frequency-specific benefit of theta-tACS coupled with TMR during sleep on memory performance, neither for continuous nor time-locked stimulation. In fact, both stimulation protocols blocked the TMR-induced memory benefits during sleep, resulting in no memory enhancement by TMR in both the theta and control conditions. No frequency-specific effect was found on the power analyses of the electroencephalogram. We conclude that tACS might have an unspecific blocking effect on memory benefits typically observed after TMR during non-REM sleep.

A comprehensive approach for evaluating the virucidal performance of domestic laundry detergents under practical conditions.

AIMS: We aimed to develop a method to assess the virucidal performance of domestic laundry in a lab-scale washing machine (Rotawash) based on EN 17658. METHODS AND RESULTS: For method development, virus recovery was investigated after drying on cotton carriers for three test viruses murine norovirus (MNV), modified vaccinia virus Ankara (MVA), and bovine coronavirus (BCoV), followed by washing simulations in flasks and Rotawash. MNV and MVA demonstrated sufficient recovery from carriers after drying and washing (up to 40°C and 60 min). BCoV exhibited lower recovery, indicating less relevance as a test virus. Rotawash efficacy tests conducted with MNV, a resistant, non-enveloped virus, showed limited efficacy of a bleach-free detergent, aligning with results from a domestic washing machine. Rotawash washes achieved higher reductions in infectious virus titers than suspension tests, indicating the role of washing mechanics in virus removal. CONCLUSIONS: This study established a practical method to test the virucidal efficacy of laundry detergents in Rotawash, simulating domestic washing.

A standardized wound infection model for antimicrobial testing of wound dressings in vitro.

To investigate the effectiveness of antimicrobial agents against wound infections, experiments using either 2D cultures with planktonic microorganisms or animal infection models are frequently carried out. However, the transferability of the results to human skin is limited by the lack of complexity of the 2D models or by the poor translation of the results from animal models. Hence, there is a need for wound infection models capable of assessing antimicrobial agents. In this study, an easily standardized wound infection model was established. This model consists of a mechanically wounded human skin model on a collagen matrix infected with various clinically relevant bacteria. Infection of the model led to recognition of the pathogens and induction of an inflammatory response. The untreated infection spread over time, causing significant tissue damage. By applying an antimicrobial-releasing wound dressing, the bacterial load could be reduced and the success of the treatment could be further measured by a decrease in the inflammatory reaction. In conclusion, this wound infection model can be used to evaluate new antimicrobial therapeutics as well as to study host-pathogen interactions.

Revision total hip arthroplasty using a modular fluted, tapered revision femoral component and interlocking screws in Vancouver B3 periprosthetic fractures with insufficient bone at the isthmus.

Aims: Revision total hip arthroplasty in patients with Vancouver type B3 fractures with Paprosky type IIIA, IIIB, and IV femoral defects are difficult to treat. One option for Paprovsky type IIIB and IV defects involves modular cementless, tapered, revision femoral components in conjunction with distal interlocking screws. The aim of this study was to analyze the rate of reoperations and complications and union of the fracture, subsidence of the stem, mortality, and the clinical outcomes in these patients. Methods: A total of 46 femoral components in patients with Vancouver B3 fractures (23 with Paprosky type IIIA, 19 with type IIIB, and four with type IV defects) in 46 patients were revised with a transfemoral approach using a modular, tapered, cementless revision Revitan curved femoral component with distal cone-in-cone fixation and prospectively followed for a mean of 48.8 months (SD 23.9; 24 to 112). The mean age of the patients was 80.4 years (66 to 100). Additional distal interlocking was also used in 23 fractures in which distal cone-in-cone fixation in the isthmus was < 3 cm. Results: One patient (2.2%) died during the first postoperative year. After six months, 43 patients (93.5%) had osseous, and three had fibrous consolidation of the fracture and the bony flap, 42 (91.3%) had bony ingrowth and four had stable fibrous fixation of the stem. No patient had radiolucency around the interlocking screws and no screw broke. One patient had non-progressive subsidence and two had a dislocation. The mean Harris Hip Score increased from of 57.8 points (SD 7.9) three months postoperatively to 76.1 points (SD 10.7) 24 months postoperatively. Conclusion: The 2° tapered, fluted revision femoral component with distal cone-in-cone-fixation, combined with additional distal interlocking in patients with bony deficiency at the isthmus, led to reproducibly good results in patients with a Vancouver B3 fracture and Paprosky type IIIA, IIIB, and IV defects with regard to union of the fracture, subsidence or loosening of the stem, and clinical outcomes.

ROP-ET: a prospective phase III trial investigating the efficacy and safety of ropeginterferon alfa-2b in essential thrombocythemia patients with limited treatment options.

Interferon-based therapies, such as ropeginterferon alfa-2b have emerged as promising disease-modifying agents for myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET). Current ET treatments aim to normalize hematological parameters and reduce the thrombotic risk, but they do not modify the natural history of the disease and hence, have no impact on disease progression. Ropeginterferon alfa-2b (trade name BESREMi®), a novel, monopegylated interferon alfa-2b with an extended administration interval, has demonstrated a robust and sustained efficacy in polycythemia vera (PV) patients. Given the similarities in disease pathophysiology and treatment goals, ropeginterferon alfa-2b holds promise as a treatment option for ET. The ROP-ET trial is a prospective, multicenter, single-arm phase III study that includes patients with ET who are intolerant or resistant to, and/or are ineligible for current therapies, such as hydroxyurea (HU), anagrelide (ANA), busulfan (BUS) and pipobroman, leaving these patients with limited treatment options. The primary endpoint is a composite response of hematologic parameters and disease-related symptoms, according to modified European LeukemiaNet (ELN) criteria. Secondary endpoints include improvements in symptoms and quality of life, molecular response and the safety profile of ropeginterferon alfa-2b. Over a 3-year period the trial assesses longer term outcomes, particularly the effects on allele burden and clinical outcomes, such as disease-related symptoms, vascular events and disease progression. No prospective clinical trial data exist for ropeginterferon alfa-2b in the planned ET study population and this study will provide new findings that may contribute to advancing the treatment landscape for ET patients with limited alternatives. TRIAL REGISTRATION: EU Clinical Trials Register; EudraCT, 2023-505160-12-00; Registered on October 30, 2023.

Modulating the difficulty of a visual oddball-like task and P3m amplitude.

It is often necessary to modulate the difficulty of an experimental task without changing physical stimulus characteristics that are known to modulate event-related potentials. Here, we developed a new, oddball-like visual discrimination task with varying levels of difficulty despite using almost identical visual stimuli. Gabor patches of one orientation served as frequent standard stimuli with 75% probability. Gabor patches with a slightly different orientation served as infrequent target stimuli (25% probability). Analyzing the behavioral outcomes revealed a successful modulation of task difficulty, i.e. the hard condition revealed decreased d' values and longer reaction times for standard stimuli. In addition, we recorded MEG and computed event-related fields in response to the stimuli. In line with our expectation, the amplitude of the P3m was reduced in the hard condition. We localized the sources of the P3m with a focus on those that are modulated by changes in task difficulty. The sources of P3m modulation by difficulty were found primarily in the centro-parietal regions of both hemispheres. Additionally, we found significant differences in source activity between the easy and hard conditions in parts of the pre and post-central gyrus and inferior parietal lobe. Our findings are in line with previous research suggesting that the brain areas responsible for the conventional P3m generators also contribute to a modulation by task difficulty.

Imetelstat-mediated alterations in fatty acid metabolism to induce ferroptosis as a therapeutic strategy for acute myeloid leukemia.

Telomerase enables replicative immortality in most cancers including acute myeloid leukemia (AML). Imetelstat is a first-in-class telomerase inhibitor with clinical efficacy in myelofibrosis and myelodysplastic syndromes. Here, we develop an AML patient-derived xenograft resource and perform integrated genomics, transcriptomics and lipidomics analyses combined with functional genetics to identify key mediators of imetelstat efficacy. In a randomized phase II-like preclinical trial in patient-derived xenografts, imetelstat effectively diminishes AML burden and preferentially targets subgroups containing mutant NRAS and oxidative stress-associated gene expression signatures. Unbiased, genome-wide CRISPR/Cas9 editing identifies ferroptosis regulators as key mediators of imetelstat efficacy. Imetelstat promotes the formation of polyunsaturated fatty acid-containing phospholipids, causing excessive levels of lipid peroxidation and oxidative stress. Pharmacological inhibition of ferroptosis diminishes imetelstat efficacy. We leverage these mechanistic insights to develop an optimized therapeutic strategy using oxidative stress-inducing chemotherapy to sensitize patient samples to imetelstat causing substantial disease control in AML.

Aggregates of nonmuscular myosin IIA in erythrocytes associate with GATA1- and GFI1B-related thrombocytopenia.

BACKGROUND: The transcription factor GATA1 is an essential regulator of erythroid cell gene expression and maturation and is also relevant for platelet biogenesis. GATA1-related thrombocytopenia (GATA1-RT) is a rare X-linked inherited platelet disorder (IPD) characterized by macrothrombocytopenia and dyserythropoiesis. Enlarged platelet size, reduced platelet granularity, and noticeable red blood cell anisopoikilocytosis are characteristic but unspecific morphological findings in GATA1-RT. OBJECTIVES: To expand the investigation of platelet phenotype of patients with GATA1-RT by light- and immunofluorescence microscopy on a blood smear. METHODS: We assessed blood smears by light- and immunofluorescence microscopy after May-Grünwald Giemsa staining using a set of 13 primary antibodies against markers belonging to different platelet structures. Antibody binding was visualized by fluorescently labeled secondary antibodies. RESULTS: We investigated 12 individuals with genetically confirmed GATA1-RT from 8 unrelated families. While confirming the already known characteristic of platelet morphology (platelet macrocytosis and reduced expression of markers for α-granules), we also found aggregates of nonmuscular myosin heavy chain II A (NMMIIA) in the erythrocytes in all individuals (1-3 aggregates/cell, 1-3 µm diameter). By systematically reanalyzing blood smears from a cohort of patients with 19 different forms of IPD, we found similar NMMIIA aggregates in the red blood cells only in subjects with GFI1B-related thrombocytopenia (GFI1B-RT), the other major IPD featured by dyserythropoiesis. CONCLUSION: Aggregates of NMMIIA in the erythrocytes associate with GATA1-RT and GFI1B-RT and can facilitate their diagnosis on blood smears. This previously unreported finding might represent a novel marker of dyserythropoiesis assessable in peripheral blood.

Immunoproteasome function maintains oncogenic gene expression in KMT2A-complex driven leukemia.

Pharmacologic targeting of chromatin-associated protein complexes has shown significant responses in KMT2A-rearranged (KMT2A-r) acute myeloid leukemia (AML) but resistance frequently develops to single agents. This points to a need for therapeutic combinations that target multiple mechanisms. To enhance our understanding of functional dependencies in KMT2A-r AML, we have used a proteomic approach to identify the catalytic immunoproteasome subunit PSMB8 as a specific vulnerability. Genetic and pharmacologic inactivation of PSMB8 results in impaired proliferation of murine and human leukemic cells while normal hematopoietic cells remain unaffected. Disruption of immunoproteasome function drives an increase in transcription factor BASP1 which in turn represses KMT2A-fusion protein target genes. Pharmacologic targeting of PSMB8 improves efficacy of Menin-inhibitors, synergistically reduces leukemia in human xenografts and shows preserved activity against Menin-inhibitor resistance mutations. This identifies and validates a cell-intrinsic mechanism whereby selective disruption of proteostasis results in altered transcription factor abundance and repression of oncogene-specific transcriptional networks. These data demonstrate that the immunoproteasome is a relevant therapeutic target in AML and that targeting the immunoproteasome in combination with Menin-inhibition could be a novel approach for treatment of KMT2A-r AML.

Higher Mortality Is Not a Universal Cost of Dispersal: A Case Study in African Wild Dogs.

AbstractMortality is considered one of the main costs of dispersal. A reliable evaluation of mortality, however, is often hindered by a lack of information about the fate of individuals that disappear under unexplained circumstances (i.e., missing individuals). Here, we addressed this uncertainty by applying a Bayesian mortality analysis that inferred the fate of missing individuals according to information from individuals with known fate. Specifically, we tested the hypothesis that mortality during dispersal is higher than mortality among nondispersers using 32 years of mark-resighting data from a free-ranging population of the endangered African wild dog (Lycaon pictus) in northern Botswana. Contrary to expectations, we found that mortality during dispersal was lower than mortality among nondispersers, indicating that higher mortality is not a universal cost of dispersal. Our findings suggest that group living can incur costs for certain age classes, such as limited access to resources as group density increases, that exceed the mortality costs associated with dispersal. By challenging the accepted expectation of higher mortality during dispersal, we urge for further investigations of this key life history trait and propose a robust statistical approach to reduce bias in mortality estimates.

Associations of spleen volume with markers of blood count and lipid profile in a large population-based study.

Background: The aim of our study was to investigate associations of spleen volume with blood count markers and lipid profile in the general population. Materials & methods: Cross-sectional data from 1,106 individuals aged 30-90 years from the population-based Study of Health in Pomerania (SHIP-START-2) were analyzed. Blood count markers included red blood cell (RBC) counts, hemoglobin, platelet count, and white blood cell (WBC) counts. Lipid profile included total-cholesterol, high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C) as well as triglycerides. Linear regression models adjusted for age, sex, body height, and weight were used to associate standardized spleen volume with blood counts and lipid profile markers. Results: Spleen volume was positively associated with RBC (ß = 0.05; 95% confidence interval [CI] = 0.03 to 0.08) and hemoglobin (ß = 0.05; 95% CI = 0.01 to 0.09) but inversely with platelet count (ß = -16.3; 95% CI = -20.5 to -12.1) and WBC (ß = -0.25; 95% CI = -0.37 to -0.14). Furthermore, spleen volume showed inverse associations with total cholesterol (ß = -0.17; 95% CI = -0.24 to -0.09), HDL-C (ß = -0.08; 95% CI = -0.10 to -0.05), and LDL-C (ß = -0.12; 95% CI = -0.17 to -0.06). There was no significant association of spleen volume with triglycerides. Conclusion: Our study showed that the spleen volume is associated with markers of the blood count and lipid profile in the general population.