Antibodies and complement are key drivers of thrombosis.

Venous thromboembolism (VTE) is a common, deadly disease with an increasing incidence despite preventive efforts. Clinical observations have associated elevated antibody concentrations or antibody-based therapies with thrombotic events. However, how antibodies contribute to thrombosis is unknown. Here, we show that reduced blood flow enabled immunoglobulin M (IgM) to bind to FcµR and the polymeric immunoglobulin receptor (pIgR), initiating endothelial activation and platelet recruitment. Subsequently, the procoagulant surface of activated platelets accommodated antigen- and FcγR-independent IgG deposition. This leads to classical complement activation, setting in motion a prothrombotic vicious circle. Key elements of this mechanism were present in humans in the setting of venous stasis as well as in the dysregulated immunothrombosis of COVID-19. This antibody-driven thrombosis can be prevented by pharmacologically targeting complement. Hence, our results uncover antibodies as previously unrecognized central regulators of thrombosis. These findings carry relevance for therapeutic application of antibodies and open innovative avenues to target thrombosis without compromising hemostasis.

DNA methylation controls stemness of astrocytes in health and ischaemia.

Astrocytes are the most abundant cell type in the mammalian brain and provide structural and metabolic support to neurons, regulate synapses and become reactive after injury and disease. However, a small subset of astrocytes settles in specialized areas of the adult brain where these astrocytes instead actively generate differentiated neuronal and glial progeny and are therefore referred to as neural stem cells1-3. Common parenchymal astrocytes and quiescent neural stem cells share similar transcriptomes despite their very distinct functions4-6. Thus, how stem cell activity is molecularly encoded remains unknown. Here we examine the transcriptome, chromatin accessibility and methylome of neural stem cells and their progeny, and of astrocytes from the striatum and cortex in the healthy and ischaemic adult mouse brain. We identify distinct methylation profiles associated with either astrocyte or stem cell function. Stem cell function is mediated by methylation of astrocyte genes and demethylation of stem cell genes that are expressed later. Ischaemic injury to the brain induces gain of stemness in striatal astrocytes7. We show that this response involves reprogramming the astrocyte methylome to a stem cell methylome and is absent if the de novo methyltransferase DNMT3A is missing. Overall, we unveil DNA methylation as a promising target for regenerative medicine.

Sensitizing protective tumor microenvironments to antibody-mediated therapy.

Therapy-resistant microenvironments represent a major barrier toward effective elimination of disseminated malignancies. Here, we show that select microenvironments can underlie resistance to antibody-based therapy. Using a humanized model of treatment refractory B cell leukemia, we find that infiltration of leukemia cells into the bone marrow rewires the tumor microenvironment to inhibit engulfment of antibody-targeted tumor cells. Resistance to macrophage-mediated killing can be overcome by combination regimens involving therapeutic antibodies and chemotherapy. Specifically, the nitrogen mustard cyclophosphamide induces an acute secretory activating phenotype (ASAP), releasing CCL4, IL8, VEGF, and TNFα from treated tumor cells. These factors induce macrophage infiltration and phagocytic activity in the bone marrow. Thus, the acute induction of stress-related cytokines can effectively target cancer cells for removal by the innate immune system. This synergistic chemoimmunotherapeutic regimen represents a potent strategy for using conventional anticancer agents to alter the tumor microenvironment and promote the efficacy of targeted therapeutics.

Analyzing single-cell bisulfite sequencing data with MethSCAn.

Single-cell bisulfite sequencing (scBS) is a technique that enables the assessment of DNA methylation at single-base pair and single-cell resolution. The analysis of large datasets obtained from scBS requires preprocessing to reduce the data size, improve the signal-to-noise ratio and provide interpretability. Typically, this is achieved by dividing the genome into large tiles and averaging the methylation signals within each tile. Here we demonstrate that this coarse-graining approach can lead to signal dilution. We propose improved strategies to identify more informative regions for methylation quantification and a more accurate quantitation method than simple averaging. Our approach enables better discrimination of cell types and other features of interest and reduces the need for large numbers of cells. We also present an approach to detect differentially methylated regions between groups of cells and demonstrate its ability to identify biologically meaningful regions that are associated with genes involved in the core functions of specific cell types. Finally, we present the software tool MethSCAn for scBS data analysis ( https://anders-biostat.github.io/MethSCAn ).

BCL-2-family protein tBID can act as a BAX-like effector of apoptosis.

During apoptosis, the BCL-2-family protein tBID promotes mitochondrial permeabilization by activating BAX and BAK and by blocking anti-apoptotic BCL-2 members. Here, we report that tBID can also mediate mitochondrial permeabilization by itself, resulting in release of cytochrome c and mitochondrial DNA, caspase activation and apoptosis even in absence of BAX and BAK. This previously unrecognized activity of tBID depends on helix 6, homologous to the pore-forming regions of BAX and BAK, and can be blocked by pro-survival BCL-2 proteins. Importantly, tBID-mediated mitochondrial permeabilization independent of BAX and BAK is physiologically relevant for SMAC release in the immune response against Shigella infection. Furthermore, it can be exploited to kill leukaemia cells with acquired venetoclax resistance due to lack of active BAX and BAK. Our findings define tBID as an effector of mitochondrial permeabilization in apoptosis and provide a new paradigm for BCL-2 proteins, with implications for anti-bacterial immunity and cancer therapy.

Different transmembrane domains determine the specificity and efficiency of the cleavage activity of the γ-secretase subunit presenilin.

The γ-secretase complex catalyzes the intramembrane cleavage of C99, a carboxy-terminal fragment of the amyloid precursor protein. Two paralogs of its catalytic subunit presenilin (PS1 and PS2) are expressed which are autocatalytically cleaved into an N-terminal and a C-terminal fragment during maturation of γ-secretase. In this study, we compared the efficiency and specificity of C99 cleavage by PS1- and PS2-containing γ-secretases. Mass spectrometric analysis of cleavage products obtained in cell-free and cell-based assays revealed that the previously described lower amyloid-ß (Aß)38 generation by PS2 is accompanied by a reciprocal increase in Aß37 production. We further found PS1 and PS2 to show different preferences in the choice of the initial cleavage site of C99. However, the differences in Aß38 and Aß37 generation appear to mainly result from altered subsequent stepwise cleavage of Aß peptides. Apart from these differences in cleavage specificity, we confirmed a lower efficiency of initial C99 cleavage by PS2 using a detergent-solubilized γ-secretase system. By investigating chimeric PS1/2 molecules, we show that the membrane-embedded, nonconserved residues of the N-terminal fragment mainly account for the differential cleavage efficiency and specificity of both presenilins. At the level of individual transmembrane domains (TMDs), TMD3 was identified as a major modulator of initial cleavage site specificity. The efficiency of endoproteolysis strongly depends on nonconserved TMD6 residues at the interface to TMD2, i.e., at a putative gate of substrate entry. Taken together, our results highlight the role of individual presenilin TMDs in the cleavage of C99 and the generation of Aß peptides.

Post-transplant-cyclophosphamide and short-term Everolimus as graft-versus-host-prophylaxis in patients with relapsed/refractory lymphoma and myeloma-Final results of the phase II OCTET-EVER trial.

BACKGROUND: Conditioning regimens and the choice of immunosuppression have substantial impact on immune reconstitution after allogeneic hematopoietic stem cell transplantation (aHSCT). The pivotal mechanism to maintain remission is the induction of the graft-versus-tumor effect. Relapse as well as graft versus host disease remain common. Classic immunosuppressive strategies implementing calcineurin inhibitors (CNI) have significant toxicities, hamper the immune recovery, and reduce the anti-cancer immune response. METHODS: We designed a phase II clinical trial for patients with relapsed and refractory lymphoid malignancies undergoing aHSCT using a CNI-free approach consisting of post-transplant cyclophosphamide (PTCy) and short-term Everolimus after reduced-intensity conditioning and matched peripheral blood stem cell transplantation. The results of the 19 planned patients are presented. Primary endpoint is the cumulative incidence and severity of acute GvHD. RESULTS: Overall incidence of acute GvHD was 53% with no grade III or IV. Cumulative incidence of NRM at 1, 2, and 4 years was 11%, 11%, and 16%, respectively, with a median follow-up of 43 months. Cumulative incidence of relapse was 32%, 32%, and 42% at 1, 2, and 4 years after transplant, respectively. Four out of six early relapses were multiple myeloma patients. Overall survival was 79%, 74%, and 62% at 1, 2, and 4 years. GvHD-relapse-free-survival was 47% after 3 years. CONCLUSIONS: Using PTCy and short-term Everolimus is safe with low rates of aGvHD and no severe aGvHD or cGvHD translating into a low rate of non-relapse mortality. Our results in this difficult to treat patient population are encouraging and warrant further studies.

Disequilibrium reaction pathways and the twin-mediated growth of tabular forsterite during contact metamorphism of quartz-bearing dolomite.

The forsterite zone of the Ubehebe Peak contact aureole, Death Valley, USA consists of an outer zone of tabular/jack-straw olivine and an inner zone of subequant polyhedral olivine. Subequant polyhedral forsterite crystals close to the intrusion are small and tabular forsterite crystals farther away are larger. To investigate the formation of the two morphologies, forsterite growth experiments were conducted in cold seal pressure vessels in the CaO-MgO-SiO2-CO2-H2O system. Forsterite precipitation follows a disequilibrium reaction pathway made of three reactions: [1] tabular forsterite growth from quartz and dolomite, [2] forsterite growth from tremolite dissolution, and [3] subequant polyhedral forsterite growth from tabular forsterite dissolution. Initially, quartz reacts with dolomite to simultaneously form twinned tabular forsterite and tremolite. As quartz reacts away, forsterite precipitation continues at a slower rate through tremolite dissolution. A second generation of forsterite then precipitates on top of some tabular forsterite but has different habit and tracht. Once all the tremolite reacts away, subequant polyhedral forsterite precipitation continues at an even slower rate through dissolution of tabular forsterite. The tabular morphology of jack-straw olivine is a consequence of twin-mediated unidirectional growth; the abundance of twins being due to rapid nucleation and growth at initially high reaction affinities. Twin junctions are preferential nucleation centers for steps, so faceted growth is enhanced on {100}. This phenomenon is the twin plane re-entrant effect. Subequant polyhedral forsterite in the Ubehebe Peak inner contact aureole recrystallized and ripened from tabular forsterite. In the outer contact aureole, conditions were not conducive to recrystallization and ripening so well-developed tabular forsterite persists.

Peripheral arterial catheters in extremely preterm infants born at less than 28 weeks of gestation-a single-center experience.

The aim of this study was to perform a retrospective data analysis of established peripheral artery catheters (pAC) in extremely preterm infants. The primary outcome was the pAC life span and its correlation to gestational age, birth weight, localizations, and pAC removal. Retrospective data analysis of electronic patient records of all extremely preterm infants (born less than 28 weeks gestation) admitted to the neonatal intensive care unit in Graz (Austria) between January 2014 and December 2020. A total of 196 preterm infants with a median (IQR) gestational age of 25.7 (24.6-26.6) weeks and a birth weight of 730 (614-898) g were included. In 155 (79%) of these preterm infants, 286 pAC and six umbilical artery catheters were inserted successfully. The first pAC was inserted 2.5 (1.4-7.4) h after birth, and the median pAC life span was 57.5 (22.-107.2) h. Gestational age, birth weight, and catheter localization did not correlate with the pAC life span. The pAC localizations were the radial artery (63%), tibial posterior artery (21%), ulnar artery (6%), dorsal artery of the foot (6%), others (1%), and not documented (3%). Adverse reactions including temporarily impaired peripheral perfusion, local inflammation, extravasation, or bleeding were reported in 13% of all pAC, but none of these resulted in long-term sequelae. A median (IQR) of 9 (5-18) arterial blood samples were drawn via pAC, resulting in a notable reduction of pain stimuli.Conclusion: The use of pAC in extremely preterm infants is feasible and safe. Neither gestational age, birth weight nor localization did affect the life span of pAC. No long-term sequelae were observed, and pain events were reduced by using pAC for blood drawing. What is Known: • Peripheral artery catheters can be used for continuous blood pressure measurement and blood draw even in extremely preterm infants. • (Severe) adverse reactions such as bleeding, necrosis, or amputation occur between 1 and 4%. • What is New: • The median peripheral arty catheter life span is 58 h and is not affected by gestational age, birth weight, nor localization. • A median of nine blood samples can be taken per each single pAC and, therefore, prevent pain events in extremely preterm infants.

Impact of in situ simulation training on quality of postnatal stabilization and resuscitation-a before-and-after, non-controlled quality improvement study.

This study aimed to evaluate the impact of in situ simulation-based training on quality indicators of patient care at a level IV neonatal intensive care unit. A before-and-after, non-controlled quality improvement study was performed at the Division of Neonatology, Medical University of Graz. The educational intervention comprised a period of 4 months, with structured in situ simulation training delivered regularly for neonatal providers and nurses in interprofessional teams. The primary study outcome was the quality of non-technical skills and team interaction during actual postnatal stabilization and resuscitation. This was assessed using video recording during two 2-month observational phases before (pre-training) and after the educational intervention (post-training). Delivery room video recordings were assessed by two external, blinded neonatologists using the Anaesthetists' Non-Technical Skills (ANTS) score. Furthermore, we collected clinical patient data from video-recorded neonates during the pre- and post-training periods, and training participants' individual knowledge of neonatal resuscitation guidelines was assessed using a before- and after-questionnaire. A total of 48 healthcare professionals participated in 41 in situ simulation trainings. The level of non-technical skills and team interaction was already high in the pre-training period, and it did not further improve afterwards. Nonetheless, we observed a significant increase in the teamwork event "evaluation of plans" (0.5 [IQR 0.0-1.0] versus 1.0 [1.0-2.0], p = 0.049). Following the educational intervention, training participants' knowledge of neonatal resuscitation guidelines significantly improved, although there were no differences in secondary clinical outcome parameters. CONCLUSION: We have successfully implemented a neonatal in situ simulation training programme. The observed improvement in one teamwork event category in the post-training period demonstrates the effectiveness of the training curriculum, while also showing the potential of in situ simulation training for improving postnatal care and, ultimately, patient outcome. WHAT IS KNOWN: • In situ simulation-based training is conducted in the real healthcare environment, thus promoting experiential learning which is closely aligned with providers' actual work. • In situ simulation-based training may offer an additional benefit for patient outcomes in comparison to other instructional methodologies. WHAT IS NEW: • This observational study investigated translational patient outcomes in preterm neonates before and after delivery of high-frequency in situ simulation-based training at a level IV neonatal intensive care unit. • There was a significant increase in the frequency of one major teamwork event following the delivery of in situ simulation-based training, indicating a notable improvement in the non-technical skills domain, which is closely linked to actual team performance.

Reference ranges of peripheral-muscle oxygenation in term neonates delivered by Caesarean section during immediate transition after birth.

AIM: To establish reference ranges of peripheral-muscle regional oxygen saturation (prSO2) and peripheral fractional tissue oxygen extraction (pFTOE) during the first 15 min after birth in stable term neonates. METHODS: Secondary outcome parameters of prospective observational studies in healthy term neonates delivered by Caesarean section were analysed. prSO2 was measured on the right forearm using the INVOS 5100C monitor. pFTOE was calculated out of prSO2 and arterial oxygen saturation (SpO2). Centile charts (10th-90th) of prSO2 and pFTOE were defined during the first 15 min after birth. RESULTS: Three-hundred-five term neonates with a mean gestational age and birth weight of 39.0 ± 0.9 weeks and 3321 ± 454 g, respectively, were included. The 50th centiles of prSO2 were 39% (minute two), 52% (minute five), 71% (minute 10), and 73% (minute 15). The 50th centiles of pFTOE were 0.529 (minute two), 0.378 (minute five), 0.237 (minute 10), and 0.231 (minute 15). CONCLUSION: Reference ranges of prSO2 and pFTOE were established for term neonates delivered by Caesarean section during the immediate transition after birth. These reference ranges increase knowledge of physiological processes taking place immediately after birth and are necessary for possible future clinical applications.

Ill-defined return to sport criteria and inconsistent unsuccessful return rates caused by various reasons not necessarily related to treatment after superior labral treatments: A systematic review.

PURPOSE: The aims of this systematic review were to determine (1) which criteria are used to determine return to sport (RTS), (2) the number of patients that are unable to RTS following any superior labral pathophysiology treatment and (3) which reasons are reported for not returning. METHODS: A systematic review was performed across 5 databases, including studies that report rates for RTS following any treatment of superior labral pathophysiology. Study quality was assessed using the MINORS criteria. Definitions for nRTS were extracted as reported in the studies. The ranges of no return to sport (nRTS) and no return to pre-injury level (nRTPL) were summarized. Reasons for nRTS and nRTPL were categorized using a predefined coding scheme. RESULTS: Among 45 studies with level of evidence ranging from II to IV, 1857 patients were involved in sports, 78% (n=1453) of whom underwent superior labral reattachment, 21% (n=381) biceps tenodesis, and 9.4% (n=175) non-operative treatment. None of the studies provided criteria for RTS and two studies provided criteria for return to pre-injury level (RTPL). The ranges of nRTS and nRTPL varied following superior labral reattachment (0-60%, n=206; 0-89%, n=424, respectively), biceps tenodesis (0-25%, n=43; 3,8-48%, n =78) and nonoperative treatment (11-75%, n=62; 18-100%, n=78). Reasons for nRTS and nRTPL were related to physical sensations (pain, feeling of instability, discomfort, weakness, lack of motion), psychological factors (fear of reinjury, lack of confidence), personal factors (lifestyle change, social reasons) and injury at another site. CONCLUSION: Criteria for determining successful RTS and RTPL following superior labral pathophysiology treatment were not reported by the majority of studies. The nRTS and nRTPL rates varied greatly within and between treatments. The reasons for this unsuccessful return were diverse and related to physical sensations, psychological factors, personal factors and injury unrelated to treatment. LEVEL OF EVIDENCE: Level IV; Systematic Review.

Patient-Reported Outcome Measures Show No Relevant Change Between 1-Year and 2-Year Follow-Up After Treatment for Anterior Shoulder Instability: A Systematic Review.

PURPOSE: To compare patient-reported outcome measures (PROMs) at 1-year and 2-year follow-up after treatment for anterior shoulder instability. METHODS: Randomized controlled trials and prospective studies that evaluated and reported PROMs after a capsulolabral repair (with or without remplissage), bone augmentation, or nonoperative treatment to treat anterior shoulder instability at both 1-year and 2-year follow-up were included. PROMs were compared between 1-year and 2-year follow-up; forest plots with mean difference were created to compare baseline, 1-year, and 2-year follow-up; and scatterplots were created to visualize clinical improvement over time. RESULTS: Fourteen studies, comprising 923 patients, with levels of evidence Level I and II were included. Nine PROMs, of which predominantly were the Western Ontario Shoulder Instability Index (WOSI; 11 studies; 79%), were evaluated. Minimal to no statistically significant change in WOSI, Oxford Shoulder Instability Score, American Shoulder and Elbow Surgeons (ASES), Subjective Shoulder Value, Simple Shoulder Test, Disabilities of Arm, Shoulder, and Hand (DASH), Quick DASH, Single Assessment Numeric Evaluation, or visual analog scale was observed between 1-year and 2-year follow-up. Pooling of the WOSI, Oxford Shoulder Instability Score, ASES, and Single Assessment Numeric Evaluation demonstrated improvement from baseline to 1-year follow-up and minimal to no change between 1-year and 2-year follow-up. Scatterplots of the WOSI and ASES demonstrated the most improvement within 6 months and no clear improvement after 1-year follow-up. Recurrence rates increased with time but varied between studies. CONCLUSIONS: In contrast to recurrence rates, which have been shown to increase with time, minimal to no statistically significant change was observed for any of the included PROMs between 1-year and 2-year follow-up. This finding raises the question as to whether it is necessary to evaluate PROMs in long-term follow-up of patients after shoulder stabilization treatment. LEVEL OF EVIDENCE: Level II, systematic review of Level I and II studies.

Methodology and development of a machine learning probability calculator: Data heterogeneity limits ability to predict recurrence after arthroscopic Bankart repair.

PURPOSE: The aim of this study was to develop and train a machine learning (ML) algorithm to create a clinical decision support tool (i.e., ML-driven probability calculator) to be used in clinical practice to estimate recurrence rates following an arthroscopic Bankart repair (ABR). METHODS: Data from 14 previously published studies were collected. Inclusion criteria were (1) patients treated with ABR without remplissage for traumatic anterior shoulder instability and (2) a minimum of 2 years follow-up. Risk factors associated with recurrence were identified using bivariate logistic regression analysis. Subsequently, four ML algorithms were developed and internally validated. The predictive performance was assessed using discrimination, calibration and the Brier score. RESULTS: In total, 5591 patients underwent ABR with a recurrence rate of 15.4% (n = 862). Age <35 years, participation in contact and collision sports, bony Bankart lesions and full-thickness rotator cuff tears increased the risk of recurrence (all p < 0.05). A single shoulder dislocation (compared to multiple dislocations) lowered the risk of recurrence (p < 0.05). Due to the unavailability of certain variables in some patients, a portion of the patient data had to be excluded before pooling the data set to create the algorithm. A total of 797 patients were included providing information on risk factors associated with recurrence. The discrimination (area under the receiver operating curve) ranged between 0.54 and 0.57 for prediction of recurrence. CONCLUSION: ML was not able to predict the recurrence following ABR with the current available predictors. Despite a global coordinated effort, the heterogeneity of clinical data limited the predictive capabilities of the algorithm, emphasizing the need for standardized data collection methods in future studies. LEVEL OF EVIDENCE: Level IV, retrospective cohort study.

Statistical shape models that predict native glenoid width based on glenoid height are inaccurate in their current form: a cross-sectional study.

BACKGROUND: The extent of measurement errors of statistical shape models that predict native glenoid width based on glenoid height to subsequently determine the amount of anterior glenoid bone loss is unclear. Therefore, the aim of this study was to (1) create a statistical shape model based on glenoid height and width measured on 3-dimensional computed tomography (3D-CT) and determine the accuracy through measurement errors and (2) determine measurement errors of existing 3D-CT statistical shape models. MATERIALS AND METHODS: A retrospective cross-sectional study included all consecutive patients who underwent CT imaging before undergoing primary surgical treatment of traumatic anterior shoulder dislocation between 2007 and 2022 at the Tohoku University Hospital and affiliated hospitals. Patients were included when instability was unilateral and CT scans of both the injured and contralateral uninjured shoulder were available. 3D segmentations were created and glenoid height and width of the injured and contralateral uninjured side (gold standard) were measured. Accuracy was determined through measurement errors, which were defined as a percentage error deviation from native glenoid width (contralateral uninjured glenoid), calculated as follows: measurement error = [(estimated glenoid width with a statistical shape model - native glenoid width) / native glenoid width] × 100%. A linear regression analysis was performed to create a statistical shape model based on glenoid height according to the formula: native glenoid width = a × glenoid height + b. RESULTS: The diagnosis and procedure codes identified 105 patients, of which 69 (66%) were eligible for inclusion. Glenoid height demonstrated a very strong correlation (r = 0.80) with native glenoid width. The linear regression formula based on this cohort was as follows: native glenoid width = 0.75 × glenoid height - 0.61, and it demonstrated an absolute average measurement error of 5% ± 4%. The formulas by Giles et al, Chen et al and Rayes et al demonstrated absolute average measurement errors of 10% ± 7%, 6% ± 5%, and 9% ± 6%, respectively. CONCLUSION: Statistical shape models that estimate native glenoid width based on glenoid height demonstrate unacceptable measurement errors, despite a high correlation. Therefore, great caution is advised when using these models to determine glenoid bone loss percentage. To minimize errors caused by morphologic differences, preference goes to methods that use the contralateral side as reference.

MARCKS affects cell motility and response to BTK inhibitors in CLL.

Bruton tyrosine kinase (BTK) inhibitors are highly active drugs for the treatment of chronic lymphocytic leukemia (CLL). To understand the response to BTK inhibitors on a molecular level, we performed (phospho)proteomic analyses under ibrutinib treatment. We identified 3466 proteins and 9184 phosphopeptides (representing 2854 proteins) in CLL cells exhibiting a physiological ratio of phosphorylated serines (pS), threonines (pT), and tyrosines (pY) (pS:pT:pY). Expression of 83 proteins differed between unmutated immunoglobulin heavy-chain variable region (IGHV) CLL (UM-CLL) and mutated IGHV CLL (M-CLL). Strikingly, UM-CLL cells showed higher basal phosphorylation levels than M-CLL samples. Effects of ibrutinib on protein phosphorylation levels were stronger in UM-CLL, especially on phosphorylated tyrosines. The differentially regulated phosphopeptides and proteins clustered in pathways regulating cell migration, motility, cytoskeleton composition, and survival. One protein, myristoylated alanine-rich C-kinase substrate (MARCKS), showed striking differences in expression and phosphorylation level in UM-CLL vs M-CLL. MARCKS sequesters phosphatidylinositol-4,5-bisphosphate, thereby affecting central signaling pathways and clustering of the B-cell receptor (BCR). Genetically induced loss of MARCKS significantly increased AKT signaling and migratory capacity. CD40L stimulation increased expression of MARCKS. BCR stimulation induced phosphorylation of MARCKS, which was reduced by BTK inhibitors. In line with our in vitro findings, low MARCKS expression is associated with significantly higher treatment-induced leukocytosis and more pronounced decrease of nodal disease in patients with CLL treated with acalabrutinib.

Active Akt signaling triggers CLL toward Richter transformation via overactivation of Notch1.

Richter's transformation (RT) is an aggressive lymphoma that occurs upon progression from chronic lymphocytic leukemia (CLL). Transformation has been associated with genetic aberrations in the CLL phase involving TP53, CDKN2A, MYC, and NOTCH1; however, a significant proportion of RT cases lack CLL phase-associated events. Here, we report that high levels of AKT phosphorylation occur both in high-risk CLL patients harboring TP53 and NOTCH1 mutations as well as in patients with RT. Genetic overactivation of Akt in the murine Eµ-TCL1 CLL mouse model resulted in CLL transformation to RT with significantly reduced survival and an aggressive lymphoma phenotype. In the absence of recurrent mutations, we identified a profile of genomic aberrations intermediate between CLL and diffuse large B-cell lymphoma. Multiomics assessment by phosphoproteomic/proteomic and single-cell transcriptomic profiles of this Akt-induced murine RT revealed an S100 protein-defined subcluster of highly aggressive lymphoma cells that developed from CLL cells, through activation of Notch via Notch ligand expressed by T cells. Constitutively active Notch1 similarly induced RT of murine CLL. We identify Akt activation as an initiator of CLL transformation toward aggressive lymphoma by inducing Notch signaling between RT cells and microenvironmental T cells.

Identifying crustal contributions in the Patagonian Chon Aike Silicic Large Igneous Province.

The volcanic rocks of the Chon Aike Silicic Large Igneous Province (CASP) are recognized as magmas dominantly produced by crustal anatexis. Investigating the zircon of the CASP provides an opportunity to gain further insight into geochemical and isotopic differences of the potential magmatic sources (i.e., crust versus mantle), to identify crustal reservoirs that contributed to the felsic magmas during anatexis, and to quantify the contributions of the respective sources. We present a combined zircon oxygen and hafnium isotope and trace element dataset for 16 volcanic units of the two youngest volcanic phases in Patagonia, dated here with LA-ICP-MS U-Pb geochronology at ca. 148-153 Ma (El Quemado Complex, EQC) and ca. 159 Ma (western Chon Aike Formation, WCA). The EQC zircon have 18O-enriched values (δ18O from 7 to 9.5‰) with correspondingly negative initial εHf values (- 2.0 to - 8.0). The WCA zircon have δ18O values between 6 and 7‰ and εHf values ranging between - 4.0 and + 1.5. Binary δ18O-εHf mixing models require an average of 70 and 60% melt derived from partial melting of isotopically distinct metasedimentary basements for the EQC and WCA, respectively. Zircon trace element compositions are consistent with anatexis of sedimentary protoliths derived from LIL-depleted upper continental crustal sources. The overlap between a high heat flux environment (i.e., widespread extension and lithospheric thinning) during supercontinental breakup and a fertile metasedimentary crust was key in producing voluminous felsic volcanism via anatexis following the injection and emplacement of basaltic magmas into the lower crust. Supplementary Information: The online version contains supplementary material available at 10.1007/s00410-023-02065-1.

Cerebral oxygenation immediately after birth and long-term outcome in preterm neonates-a retrospective analysis.

BACKGROUND: Prematurity is associated with increased risk for morbidity and mortality. Aim of this study was to evaluate whether cerebral oxygenation during fetal-to-neonatal transition period was associated with long-term outcome in very preterm neonates. METHODS: Preterm neonates ≤ 32 weeks of gestation and/or ≤ 1500 g with measurements of cerebral regional oxygen saturation (crSO2) and cerebral fractional tissue oxygen extraction (cFTOE) within the first 15 min after birth were analysed retrospectively. Arterial oxygen saturation (SpO2) and heart rate (HR) were measured with pulse oximetry. Long-term outcome was assessed at two years using "Bayley Scales of Infant Development" (BSID-II/III). Included preterm neonates were stratified into two groups: adverse outcome group (BSID-III ≤ 70 or testing not possible due to severe cognitive impairment or mortality) or favorable outcome group (BSID-III > 70). As the association between gestational age and long-term outcome is well known, correction for gestational age might disguise the potential association between crSO2 and neurodevelopmental impairment. Therefore, due to an explorative approach the two groups were compared without correction for gestational age. RESULTS: Forty-two preterm neonates were included: adverse outcome group n = 13; favorable outcome group n = 29. Median(IQR) gestational age and birth weight were 24.8 weeks (24.2-29.8) and 760 g (670-1054) in adverse outcome group and 30.6 weeks (28.1-32.0) (p = 0.009*) and 1250 g (972-1390) (p = 0.001*) in the favorable outcome group, respectively. crSO2 was lower (significant in 10 out of 14 min) and cFTOE higher in adverse outcome group. There were no difference in SpO2, HR and fraction of inspired oxygen (FiO2), except for FiO2 in minute 11, with higher FiO2 in the adverse outcome group. CONCLUSION: Preterm neonates with adverse outcome had beside lower gestational age also a lower crSO2 during immediate fetal-to-neonatal transition when compared to preterm neonates with age appropriate outcome. Lower gestational age in the adverse outcome group would suggest beside lower crSO2 also lower SpO2 and HR in this group, which were however similar in both groups.

Cardiac output and regional-cerebral-oxygen-saturation in preterm neonates during immediate postnatal transition: An observational study.

AIM: To examine potential correlations between cardiac output (CO) with cerebral-regional-oxygen-saturation (crSO2 ) and cerebral-fractional-tissue-oxygen-extraction (cFTOE) during immediate foetal-to-neonatal transition in term and preterm neonates with and without respiratory support. METHODS: Post hoc analyses of secondary outcome parameters of prospective observational studies were performed. We included neonates with cerebral near-infrared-spectroscopy (NIRS) monitoring and an oscillometric blood pressure measurement at minute 15 after birth. Heart rate (HR) and arterial oxygen saturation (SpO2 ) were monitored. CO was calculated with Liljestrand and Zander formula and correlated with crSO2 and cFTOE. RESULTS: Seventy-nine preterm neonates and 207 term neonates with NIRS measurements and calculated CO were included. In 59 preterm neonates (mean gestational age (GA): 29.4 ± 3.7 weeks) with respiratory support, CO correlated significantly positively with crSO2 and significantly negatively with cFTOE. In 20 preterm neonates (GA 34.9 ± 1.3 weeks) without respiratory support and in 207 term neonates with and without respiratory support, CO correlated neither with crSO2 nor with cFTOE. CONCLUSION: In compromised preterm neonates with lower gestational age and in need of respiratory support, CO was associated with crSO2 and cFTOE, whereas in stable preterm neonates with higher gestational age as well as in term neonates with and without respiratory support, no associations were observed.