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Heterochromatic loci marked by histone H3 lysine 9 dimethylation (H3K9me2) are enriched at the nuclear periphery in metazoans, but the effect of spatial position on heterochromatin function has not been defined. Here, we remove three nuclear lamins and lamin B receptor (LBR) in mouse embryonic stem cells (mESCs) and show that heterochromatin detaches from the nuclear periphery. Mutant mESCs sustain naïve pluripotency and maintain H3K9me2 across the genome but cannot repress H3K9me2-marked genes or transposons. Further, mutant cells fail to differentiate into epiblast-like cells (EpiLCs), a transition that requires the expansion of H3K9me2 across the genome. Mutant EpiLCs can silence naïve pluripotency genes and activate epiblast-stage genes. However, H3K9me2 cannot repress markers of alternative fates, including primitive endoderm. We conclude that the nuclear periphery controls the spatial position, dynamic remodeling, and repressive capacity of H3K9me2-marked heterochromatin to shape cell fate decisions.
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We report ultrabroadband two-dimensional electronic spectroscopy (2D ES) measurements obtained in the pump-probe geometry using conventional optics. A phase-stabilized Michelson interferometer provides the pump-pulse delay interval, τ1, necessary to obtain the excitation-frequency dimension. Spectral resolution of the probe beam provides the detection-frequency dimension, ω3. The interferometer incorporates active phase stabilization via a piezo stage and feedback from interference of a continuous-wave reference laser detected in quadrature. To demonstrate the method, we measured a well-characterized laser dye sample and obtained the known peak structure. The vibronic peaks are modulated as a function of the waiting time, τ2, by vibrational wave packets. The interferometer simplifies ultrabroadband 2D ES measurements and analysis.
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Phenotypic assays have become an established approach to drug discovery. Greater disease relevance is often achieved through cellular models with increased complexity and more detailed readouts, such as gene expression or advanced imaging. However, the intricate nature and cost of these assays impose limitations on their screening capacity, often restricting screens to well-characterized small compound sets such as chemogenomics libraries. Here, we outline a cheminformatics approach to identify a small set of compounds with likely novel mechanisms of action (MoAs), expanding the MoA search space for throughput limited phenotypic assays. Our approach is based on mining existing large-scale, phenotypic high-throughput screening (HTS) data. It enables the identification of chemotypes that exhibit selectivity across multiple cell-based assays, which are characterized by persistent and broad structure activity relationships (SAR). We validate the effectiveness of our approach in broad cellular profiling assays (Cell Painting, DRUG-seq, and Promotor Signature Profiling) and chemical proteomics experiments. These experiments revealed that the compounds behave similarly to known chemogenetic libraries, but with a notable bias toward novel protein targets. To foster collaboration and advance research in this area, we have curated a public set of such compounds based on the PubChem BioAssay dataset and made it available for use by the scientific community.
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Découverte de médicament , Tests de criblage à haut débit , Bibliothèques de petites molécules , Découverte de médicament/méthodes , Tests de criblage à haut débit/méthodes , Chimio-informatique/méthodes , Bibliothèques de petites molécules/composition chimique , Relation structure-activitéRÉSUMÉ
A hexanucleotide repeat expansion (HRE) in C9orf72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). However, patients with the HRE exhibit a wide disparity in clinical presentation and age of symptom onset suggesting an interplay between genetic background and environmental stressors. Neurotrauma as a result of traumatic brain or spinal cord injury has been shown to increase the risk of ALS/FTD in epidemiological studies. Here, we combine patient-specific induced pluripotent stem cells (iPSCs) with a custom-built device to deliver biofidelic stretch trauma to C9orf72 patient and isogenic control motor neurons (MNs) in vitro. We find that mutant but not control MNs exhibit selective degeneration after a single incident of severe trauma, which can be partially rescued by pretreatment with a C9orf72 antisense oligonucleotide. A single incident of mild trauma does not cause degeneration but leads to cytoplasmic accumulation of TDP-43 in C9orf72 MNs. This mislocalization, which only occurs briefly in isogenic controls, is eventually restored in C9orf72 MNs after 6 days. Lastly, repeated mild trauma ablates the ability of patient MNs to recover. These findings highlight alterations in TDP-43 dynamics in C9orf72 ALS/FTD patient MNs following traumatic injury and demonstrate that neurotrauma compounds neuropathology in C9orf72 ALS/FTD. More broadly, our work establishes an in vitro platform that can be used to interrogate the mechanistic interactions between ALS/FTD and neurotrauma.
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PURPOSE: FGFR2 and FGFR3 show oncogenic activation in many cancer types, often through chromosomal fusion or extracellular domain mutation. FGFR2 and FGFR3 alterations are most prevalent in intrahepatic cholangiocarcinoma (ICC) and bladder cancers, respectively, and multiple selective reversible and covalent pan-FGFR tyrosine kinase inhibitors (TKI) have been approved in these contexts. However, resistance, often due to acquired secondary mutations in the FGFR2/3 kinase domain, limits efficacy. Resistance is typically polyclonal, involving a spectrum of different mutations that most frequently affect the molecular brake and gatekeeper residues (N550 and V565 in FGFR2). EXPERIMENTAL DESIGN: Here, we characterize the activity of the next-generation covalent FGFR inhibitor, KIN-3248, in preclinical models of FGFR2 fusion+ ICC harboring a series of secondary kinase domain mutations, in vitro and in vivo. We also test select FGFR3 alleles in bladder cancer models. RESULTS: KIN-3248 exhibits potent selectivity for FGFR1-3 and retains activity against various FGFR2 kinase domain mutations, in addition to being effective against FGFR3 V555M and N540K mutations. Notably, KIN-3248 activity extends to the FGFR2 V565F gatekeeper mutation, which causes profound resistance to currently approved FGFR inhibitors. Combination treatment with EGFR or MEK inhibitors potentiates KIN-3248 efficacy in vivo, including in models harboring FGFR2 kinase domain mutations. CONCLUSIONS: Thus, KIN-3248 is a novel FGFR1-4 inhibitor whose distinct activity profile against FGFR kinase domain mutations highlights its potential for the treatment of ICC and other FGFR-driven cancers.
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Mutation , Inhibiteurs de protéines kinases , Récepteur FGFR2 , Tumeurs de la vessie urinaire , Animaux , Humains , Souris , Lignée cellulaire tumorale , Prolifération cellulaire/effets des médicaments et des substances chimiques , Cholangiocarcinome/traitement médicamenteux , Cholangiocarcinome/génétique , Cholangiocarcinome/anatomopathologie , Résistance aux médicaments antinéoplasiques/génétique , Inhibiteurs de protéines kinases/pharmacologie , Inhibiteurs de protéines kinases/usage thérapeutique , Récepteur FGFR2/génétique , Récepteur FGFR2/antagonistes et inhibiteurs , Récepteur de type 3 des facteurs de croissance fibroblastique/génétique , Récepteur de type 3 des facteurs de croissance fibroblastique/antagonistes et inhibiteurs , Tumeurs de la vessie urinaire/traitement médicamenteux , Tumeurs de la vessie urinaire/génétique , Tumeurs de la vessie urinaire/anatomopathologie , Tests d'activité antitumorale sur modèle de xénogreffeRÉSUMÉ
Predicting compound activity in assays is a long-standing challenge in drug discovery. Computational models based on compound-induced gene expression signatures from a single profiling assay have shown promise toward predicting compound activity in other, seemingly unrelated, assays. Applications of such models include predicting mechanisms-of-action (MoA) for phenotypic hits, identifying off-target activities, and identifying polypharmacologies. Here, we introduce transcriptomics-to-activity transformer (TAT) models that leverage gene expression profiles observed over compound treatment at multiple concentrations to predict the compound activity in other biochemical or cellular assays. We built TAT models based on gene expression data from a RASL-seq assay to predict the activity of 2692 compounds in 262 dose-response assays. We obtained useful models for 51% of the assays, as determined through a realistic held-out set. Prospectively, we experimentally validated the activity predictions of a TAT model in a malaria inhibition assay. With a 63% hit rate, TAT successfully identified several submicromolar malaria inhibitors. Our results thus demonstrate the potential of transcriptomic responses over compound concentration and the TAT modeling framework as a cost-efficient way to identify the bioactivities of promising compounds across many assays.
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Apprentissage profond , Paludisme , Humains , Transcriptome , Découverte de médicament/méthodes , Analyse de profil d'expression de gènesRÉSUMÉ
Fibroblast growth factor receptor (FGFR) alterations are present as oncogenic drivers and bypass mechanisms in many forms of cancer. These alterations can include fusions, amplifications, rearrangements, and mutations. Acquired drug resistance to current FGFR inhibitors often results in disease progression and unfavorable outcomes for patients. Genomic profiling of tumors refractory to current FGFR inhibitors in the clinic has revealed several acquired driver alterations that could be the target of next generation therapeutics. Herein, we describe how structure-based drug design (SBDD) was used to enable the discovery of the potent and kinome selective pan-FGFR inhibitor KIN-3248, which is active against many acquired resistance mutations. KIN-3248 is currently in phase I clinical development for the treatment of advanced tumors harboring FGFR2 and/or FGFR3 gene alterations.
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Tumeurs , Récepteur FGFR2 , Humains , Récepteur FGFR2/génétique , Tumeurs/traitement médicamenteux , Tumeurs/génétique , Mutation , Évolution de la maladie , Inhibiteurs de protéines kinases/effets indésirables , Récepteur de type 3 des facteurs de croissance fibroblastiqueRÉSUMÉ
RAF, a core signaling component of the MAPK kinase cascade, is often mutated in various cancers, including melanoma, lung, and colorectal cancers. The approved inhibitors were focused on targeting the BRAFV600E mutation that results in constitutive activation of kinase signaling through the monomeric protein (Class I). However, these inhibitors also paradoxically activate kinase signaling of RAF dimers, resulting in increased MAPK signaling in normal tissues. Recently, significant attention has turned to targeting RAF alterations that activate dimeric signaling (class II and III BRAF and NRAS). However, the discovery of a potent and selective inhibitor with biopharmaceutical properties suitable to sustain robust target inhibition in the clinical setting has proven challenging. Herein, we report the discovery of exarafenib (15), a highly potent and selective inhibitor that intercepts the RAF protein in the dimer compatible αC-helix-IN conformation and demonstrates anti-tumor efficacy in preclinical models with BRAF class I, II, and III and NRAS alterations.
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Mélanome , Protéines proto-oncogènes B-raf , Humains , Inhibiteurs de protéines kinases/pharmacologie , Inhibiteurs de protéines kinases/usage thérapeutique , Lignée cellulaire tumorale , Mélanome/anatomopathologie , Système de signalisation des MAP kinases , MutationRÉSUMÉ
Human induced pluripotent stem cell (hiPSC)-derived cells can reproduce human-specific pathophysiology, patient-specific vulnerability, and gene-environment interactions in neurological disease. Human in vitro models of neurotrauma therefore have great potential to advance the field. However, this potential cannot be realized until important biomaterials challenges are addressed. Status quo stretch injury models of neurotrauma culture cells on sheets of polydimethylsiloxane (PDMS) that are incompatible with long-term monoculture of hiPSC-derived neurons. Here, we overcame this challenge in an established human in vitro neurotrauma model by replacing PDMS with a highly biocompatible form of polyurethane (PU). This substitution allowed long-term monoculture of hiPSC-derived neurons. It also changed the biomechanics of stretch injury. We quantified these changes experimentally using high-speed videography and digital image correlation. We used finite element modeling to quantify the influence of the culture substrate's thickness, stiffness, and coefficient of friction on membrane stretch and concluded that the coefficient of friction explained most of the observed biomechanical changes. Despite these changes, we demonstrated that the modified model produced a robust, dose-dependent trauma phenotype in hiPSC-derived neuron monocultures. In summary, the introduction of this PU film makes it possible to maintain hiPSC-derived neurons in monoculture for long periods in a human in vitro neurotrauma model. In doing so, it opens new horizons in the field of neurotrauma by enabling the unique experimental paradigms (e.g., isogenic models) associated with hiPSC-derived neurons.
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BACKGROUND AND AIMS: Liver transplantation is a life-saving procedure for end-stage liver disease. However, post-transplant medication regimens are complex and non-adherence is common. Post-transplant medication non-adherence is associated with graft rejection, which can have long-term adverse consequences. Transplant centres are equipped with clinical staff that monitor patients post-transplant; however, digital health tools and proactive immunosuppression adherence monitoring has potential to improve outcomes. METHODS AND ANALYSIS: This is a patient-randomised prospective clinical trial at three transplant centres in the Northeast, Midwest and South to investigate the effects of a remotely administered adherence programme compared with usual care. The programme monitors potential non-adherence largely levering text message prompts and phenotypes the nature of the non-adhere as cognitive, psychological, medical, social or economic. Additional reminders for medications, clinical appointments and routine self-management support are incorporated to promote adherence to the entire medical regimen. The primary study outcome is medication adherence via 24-hour recall; secondary outcomes include additional medication adherence (ASK-12 self-reported scale, regimen knowledge scales, tacrolimus values), quality of life, functional health status and clinical outcomes (eg, days hospitalised). Study implementation, acceptability, feasibility, costs and potential cost-effectiveness will also be evaluated. ETHICS AND DISSEMINATION: The University of Pennsylvania Review Board has approved the study as the single IRB of record (protocol # 849575, V.1.4). Results will be published in peer-reviewed journals and summaries will be provided to study funders. TRIAL REGISTRATION NUMBER: NCT05260268.
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Maladie du foie en phase terminale , Transplantation hépatique , Humains , Études prospectives , Qualité de vie , Adhésion et observance thérapeutiquesRÉSUMÉ
Does warmth from hydrothermal springs play a vital role in the biology and ecology of abyssal animals? Deep off central California, thousands of octopus (Muusoctopus robustus) migrate through cold dark waters to hydrothermal springs near an extinct volcano to mate, nest, and die, forming the largest known aggregation of octopus on Earth. Warmth from the springs plays a key role by raising metabolic rates, speeding embryonic development, and presumably increasing reproductive success; we show that brood times for females are ~1.8 years, far faster than expected for abyssal octopods. Using a high-resolution subsea mapping system, we created landscape-scale maps and image mosaics that reveal 6000 octopus in a 2.5-ha area. Because octopuses die after reproducing, hydrothermal springs indirectly provide a food supplement to the local energy budget. Although localized deep-sea heat sources may be essential to octopuses and other warm-tolerant species, most of these unique and often cryptic habitats remain undiscovered and unexplored.
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Octopodiformes , Animaux , Femelle , Compléments alimentaires , , Écologie , Incubateurs , EauRÉSUMÉ
ABSTRACT: Many patients are affected by HIV/AIDS, and these conditions are highly prevalent worldwide. Patients with HIV/AIDS can experience debilitating wound infections that often require flap reconstruction and become challenging for surgeons to treat. In the past 5 years, mesenchymal stem cells have been tested and used as regenerative therapy to promote the growth of tissues throughout the body because of their ability to successfully promote cellular mitogenesis. To the authors' knowledge, the use of mesenchymal stem cell grafting following necrosis of a myocutaneous gracilis flap (as part of perineal wound reconstruction) has never been reported in the literature.In addition, the use of mesenchymal stem cells and regenerative medicine combined in the setting of squamous cell carcinoma of the anus with prior radiation (along with comorbid AIDS) has not been previously documented.In this report, the authors outline the case of a 60-year-old patient who had a recipient bed (perineum) complication from prior radiation therapy. Complicating the clinical picture, the patient also developed a Pseudomonal organ space infection of the pelvis leading to the failure of a vertical rectus abdominis myocutaneous flap and myocutaneous gracilis flaps. As a result, the patient underwent serial operative debridements for source control, with the application of mesenchymal stem cells, fetal bovine dermis, porcine urinary bladder xenograft, and other regenerative medicine products, achieving a highly successful clinical outcome. A procedural description for future use and replication of this method is provided.
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Tumeurs de l'anus , Carcinome épidermoïde , Infections à VIH , Lambeau musculo-cutané , , Infection de plaie , Humains , Animaux , Bovins , Périnée , Tumeurs de l'anus/chirurgie , Lambeau musculo-cutané/transplantation , Infection de plaie/chirurgie , Carcinome épidermoïde/chirurgie , Infections à VIH/chirurgie , Études rétrospectivesRÉSUMÉ
CONTEXT: The influence of several psychological characteristics on the willingness of athletes to report concussion behaviors has not been well explored. Therefore, the purpose of this study was to understand how athletic identity and sport passion predicted participants' willingness to report symptoms above what was explained by athlete demographics, concussion knowledge, and perceived seriousness of concussions. DESIGN: The study was cross-sectional. METHODS: Three-hundred and twenty-two male and female high school and club sport athletes completed survey measures of concussion knowledge, athletic identity, harmonious and obsessive passion, and degree to which athletes indicated they would report concussions and concussion symptoms. RESULTS: Athletes scored moderately high on their knowledge of symptoms and other concussion information (mean = 16.21; ± = 2.88) and above the midpoint on their attitudes and behaviors toward reporting concussion symptoms (mean = 3.64; ± = 0.70). There were no differences between gender, t(299) = -.78, P = .44, and previous concussion education, t(296) = 1.93, P = .06, related to concussion knowledge. Results of a hierarchical regression indicated that after entering athlete demographics, concussion knowledge, and perceived seriousness of concussions, of the 3 psychological variables in the final stage of the model, only obsessive passion was a significant predictor of athlete's attitudes to report a concussion. CONCLUSIONS: Perceived seriousness of concussion, perceived threat to long-term health, and obsessive passion were the strongest predictors of athlete's willingness to report concussions. Athletes who did not believe concussions posed a threat to their current or future health, and those that held an obsessive passion for sport were most at risk for not reporting concussions. Future research should continue to investigate the relationship between reporting behaviors and psychological factors.
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Traumatismes sportifs , Commotion de l'encéphale , Sports , Humains , Mâle , Femelle , Traumatismes sportifs/diagnostic , Études transversales , Commotion de l'encéphale/diagnostic , Sports/psychologie , Athlètes , Connaissances, attitudes et pratiques en santéRÉSUMÉ
BACKGROUND: Cytomegalovirus (CMV) infection is one of the most common posttransplantation infections and has been associated with increased rejection and mortality. Data in intestinal transplants recipients are limited. METHODS: This is a single-center, retrospective cohort study of all intestinal transplants performed between January 1, 2009, and August 31, 2020. We included recipients of all ages who were at risk of CMV infection. To identify the risk factors, we conducted at first univariate and multivariate analysis. For the multivariate analysis, we developed a logistic regression model based on the result of univariate analysis. RESULTS: Ninety five patients with a median age of 32 (interquartile range [IQR] 4, 50) were included. CMV donor seropositive/recipient seronegative were 17 (17.9%). Overall, 22.1% of the recipients developed CMV infection at a median time of 155 (IQR 28-254) days from transplant, including 4 CMV syndrome and 6 CMV end-organ disease. Overall, 90.4%, (19/21) developed DNAemia while on prophylaxis. Median peak viral load and time to negativity was 16â¯000 (IQR 1034-43â¯892) IU/mL and 56 (IQR 49-109) days, respectively. (Val)ganciclovir and foscarnet were utilized in 17 (80.9%) and 1 (4.76%) recipients, respectively. Recurrences of CMV DNAemia and graft rejection were observed in three and six recipients, respectively. Younger age was identified as a risk factor (p = .032, odds ratio 0.97, 95% confidence interval 0.95-0.99) to develop CMV DNAemia. CONCLUSION: A significant proportion of intestinal transplant recipients developed CMV infection while on prophylaxis. Better methods such as CMV cell mediated immunity guided prophylaxis should be used to prevent infections in this population.
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Solid Organ Transplant (SOT) recipients are at significant higher risk for COVID-19 and due to immunosuppressive medication, the immunogenicity after vaccination is suboptimal. In the previous studies, booster method showed significant benefit in this population. In the current study, we compared using a mix-and-match method vs. same vaccine as a third dose in SOT recipients. This was a patient-blinded, single center, randomized controlled trial comparing BNT162b2 vs. JNJ-78436735 vaccine as the third dose after two doses of BNT162b2 vaccine. We included adult SOT recipients with functional graft who had received two doses of BNT162b2 vaccine. Participants were randomly assigned to receive either BNT162b2 or JNJ-78436735 in one-to-one ratio. Primary outcome was SARS-CoV-2 IgG positivity at 1 month after the third dose. Sixty SOT recipients, including 36 kidney, 12 liver, 2 lung, 3 heart, and 5 combined transplants, were enrolled, and 57 recipients were analyzed per protocol. There were no statistically significant differences between the two vaccine protocols for IgG positivity (83.3% vs. 85.2% for BNT162b2 and JNJ-78436735, respectively, p = 0.85, Odds Ratio 0.95, 95% Confidence Interval 0.23-4.00). Comparison of the geometric mean titer demonstrated a higher trend with BNT162b2 (p = 0.09). In this pilot randomized controlled trial comparing mix and match method vs. uniform vaccination in SOT recipients, both vaccines were safely used. Since this was a small sample sized study, there was no statistically significant difference in immunogenicity; though, the mix and match method showed relatively lower geometric mean titer, as compared to uniform vaccine. Further studies need to be conducted to determine duration of this immunogenicity. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT05047640?term=20210641&draw=2&rank=1, identifier 20210641.
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COVID-19 , Transplantation d'organe , Vaccins , Adulte , Humains , Ad26COVS1 , Vaccin BNT162 , COVID-19/prévention et contrôle , SARS-CoV-2 , Receveurs de transplantation , Immunoglobuline G , Anticorps antivirauxRÉSUMÉ
Despite data demonstrating increased utilization of kidneys from hepatitis C virus (HCV)-infected donors, it is unknown whether this is due to an increase in the donor pool or improved organ utilization and whether data from early pilot trials were temporally associated with changes in organ utilization. We used data from the Organ Procurement and Transplantation Network on all kidney donors and recipients of kidney transplants from January 1, 2015, to March 31, 2022 to evaluate temporal changes using joinpoint regression. Our primary analyses compared donors on the basis of their HCV viremic status (HCV-infected vs HCV-negative). Kidney utilization changes were assessed by evaluating the kidney discard rate and kidneys transplanted per donor. A total of 81 833 kidney donors were included in the analysis. There was a statistically significant decrease in the discard rates of HCV-infected kidney donors from 40% to just over 20% over a 1-year period, with a concurrent increase in kidneys transplanted per donor. This increased utilization occurred in tandem with the publication of pilot trials involving HCV-infected kidney donors in HCV-negative recipients rather than an increase in the donor pool. Ongoing clinical trials may strengthen existing data, which could result in this practice becoming the accepted standard of care.
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Hépatite C , Transplantation rénale , Humains , États-Unis/épidémiologie , Hepacivirus , Rein , Donneurs de tissus , Antiviraux/usage thérapeutiqueRÉSUMÉ
Epigenetic mechanisms regulate the multilineage differentiation capacity of hematopoietic stem cells (HSCs) into a variety of blood and immune cells. Mapping the chromatin dynamics of functionally defined cell populations will shed mechanistic insight into 2 major, unanswered questions in stem cell biology: how does epigenetic identity contribute to a cell type's lineage potential, and how do cascades of chromatin remodeling dictate ensuing fate decisions? Our recent work revealed evidence of multilineage gene priming in HSCs, where open cis-regulatory elements (CREs) exclusively shared between HSCs and unipotent lineage cells were enriched for DNA binding motifs of known lineage-specific transcription factors. Oligopotent progenitor populations operating between the HSCs and unipotent cells play essential roles in effecting hematopoietic homeostasis. To test the hypothesis that selective HSC-primed lineage-specific CREs remain accessible throughout differentiation, we used ATAC-seq to map the temporal dynamics of chromatin remodeling during progenitor differentiation. We observed epigenetic-driven clustering of oligopotent and unipotent progenitors into distinct erythromyeloid and lymphoid branches, with multipotent HSCs and MPPs associating with the erythromyeloid lineage. We mapped the dynamics of lineage-primed CREs throughout hematopoiesis and identified both unique and shared CREs as potential lineage reinforcement mechanisms at fate branch points. Additionally, quantification of genome-wide peak count and size revealed overall greater chromatin accessibility in HSCs, allowing us to identify HSC-unique peaks as putative regulators of self-renewal and multilineage potential. Finally, CRISPRi-mediated targeting of ATACseq-identified putative CREs in HSCs allowed us to demonstrate the functional role of selective CREs in lineage-specific gene expression. These findings provide insight into the regulation of stem cell multipotency and lineage commitment throughout hematopoiesis and serve as a resource to test functional drivers of hematopoietic lineage fate.
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Chromatine , Hématopoïèse , Chromatine/génétique , Chromatine/métabolisme , Hématopoïèse/génétique , Cellules souches hématopoïétiques/métabolisme , Différenciation cellulaire/génétique , Lignage cellulaire/génétiqueRÉSUMÉ
The potential for high performance in many sports can be assessed by quantifying whole-body explosiveness. The backwards overhead medicine ball (BOMB) throw is commonly-used to tests this ability, but the effect of varied loading on test execution is unknown. The purpose of this study was to determine the effect of different medicine ball (MB) loads on force, velocity, and power output during the BOMB throw. Female collegiate softball and rugby players (n=31) performed the BOMB throw on a force plate using 2.7, 3.6, 4.5, and 5.5 kg MBs, with three throws per load in a randomised order, and 30 seconds rest between throws. A series of Repeated Measures ANOVAs noted no differences (p>0.05) in peak power, peak force, peak velocity, force at the moment of peak power, or velocity at the moment of peak power, across MB loads. The lack of differences among these loads indicates that coaches can likely compare kinetic characteristics of the BOMB throw within this range (2.7-5.5 kg). Therefore, coaches can use the BOMB throw with 2.7-5.5 kg MBs for training or measurement among female athletes to obtain reference data for programming or evaluation.
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Baseball , Sports , Humains , Femelle , Phénomènes biomécaniques , Muscles squelettiques , Athlètes , Force musculaireRÉSUMÉ
We demonstrate rapid imaging based on four-wave mixing (FWM) by assessing the quality of advanced materials through measurement of their nonlinear response, exciton dephasing, and exciton lifetimes. We use a WSe2 monolayer grown by chemical vapor deposition as a canonical example to demonstrate these capabilities. By comparison, we show that extracting material parameters such as FWM intensity, dephasing times, excited state lifetimes, and distribution of dark/localized states allows for a more accurate assessment of the quality of a sample than current prevalent techniques, including white light microscopy and linear micro-reflectance spectroscopy. We further discuss future improvements of the ultrafast FWM techniques by modeling the robustness of exponential decay fits to different spacing of the sampling points. Employing ultrafast nonlinear imaging in real-time at room temperature bears the potential for rapid in-situ sample characterization of advanced materials and beyond.
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Despite a significant increase in the total number of liver transplants (LTs) performed over the last 3 decades, primary biliary cholangitis (PBC) has become an uncommon indication for LT, which likely reflects the benefits of earlier diagnosis and available treatment, such as ursodeoxycholic acid (UDCA). Nonetheless, LT remains the only cure for patients with progressive PBC despite medical therapy with survival rates that are among the highest of all indications for LT. Post-LT PBC patients, however, are at increased risk of rejection and disease recurrence.