Publications by authors named "Daniel Fisher"

Background: Surgery, chemotherapy, and radiation often have limited utility for advanced metastatic disease in the liver, and despite its promising activity in select cancers, PD-1 blockade therapy similarly has minimal benefit in this setting. Curaxin, CBL0137, is an experimental anti-cancer drug that disrupts the binding of DNA to histones, destabilizes chromatin, and induces Z-DNA formation which may stimulate anti-tumor immune responses.

Methods: Murine cell lines of colon (CT26) and breast (4T1) cancer were interrogated for survival and CBL0137-associated DNA changes in vitro.

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  • Behavioral variant frontotemporal dementia (bvFTD) is characterized by a range of neuropsychiatric symptoms (NPS) that occur frequently both early and late in the illness, impacting emotional and behavioral aspects.
  • A study involving 354 participants identified four main clusters of NPS—affective, disinhibited, compulsive, and psychosis—showing that some symptoms fluctuate while others remain stable over time.
  • The findings suggest that NPS could be linked to specific brain network disruptions, providing insight for potential treatments, although the variability in symptoms indicates they may not be reliable indicators of disease progression.
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  • Researchers investigated the effects of breathing hypoxic gas (oxygen levels < 0.21) in 5 healthy volunteers over 5 days to assess safety and physiologic changes.
  • Subjects spent time in a hypoxic tent, gradually decreasing oxygen levels to as low as 0.11, with their oxygen saturation, heart rate, and other health metrics continuously monitored.
  • Findings indicated significant physiologic changes with no adverse effects, suggesting that low oxygen levels can be safely tested in hospital settings, paving the way for future studies on the therapeutic benefits of hypoxia.
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Physical inactivity contributes to over 800,000 deaths annually. Numerous non-pharmacological interventions provide a route to address this behavioural risk factor linked to the growth of non-communicable diseases. Here, we consider a nature-based intervention, specifically group outdoor health walks (GOHW), as a non-pharmacological intervention to increase physical activity and contribute to health and quality of life amongst older adults.

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Introduction: In the Medscape 2020 Compensation Report, family physicians ranked low for feeling fairly compensated, choosing their specialty again and choosing medicine again. However, the Medscape data may not represent military family physicians.

Methods: A large survey was emailed to 2,562 military family physicians via a military professional organization list-serve from February to April 2021.

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Introduction: Climate change is the single biggest health threat facing humanity, with direct and indirect impacts on mental health, yet health impacts of climate change remain notably absent from most medical school curricula. We describe a timely interactive educational session on climate change and mental health that was implemented and studied on a medical student clinical psychiatry rotation.

Methods: We developed a 1-hour introductory session on the mental health impacts of climate change and potential solutions.

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Despite the significant burden, cost, and worse prognosis of Alzheimer's disease (AD) with behavioral and psychological symptoms of dementia (BPSD), little is known about the molecular causes of these symptoms. Using antemortem assessments of BPSD in AD, we demonstrate that individual BPSD can be grouped into 4 domain factors in our cohort: affective, apathy, agitation, and psychosis. Then, we performed a transcriptome-wide analysis for each domain utilizing bulk RNA-seq of post-mortem anterior cingulate cortex (ACC) tissues.

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Mature oligodendrocytes (OLG) are the myelin-forming cells of the central nervous system. Recent work has shown a dynamic role for these cells in the plasticity of neural circuits, leading to a renewed interest in voltage-sensitive currents in OLG. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and their respective current (I) were recently identified in mature OLG and shown to play a role in regulating myelin length.

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Hyperactivation of the NF-κB cascade propagates oncogenic signaling and proinflammation, which together augments disease burden in myeloproliferative neoplasms (MPNs). Here, we systematically ablate NF-κB signaling effectors to identify core dependencies using a series of primary samples and syngeneic and patient-derived xenograft (PDX) mouse models. Conditional knockout of Rela attenuated Jak2V617F- and MPLW515L-driven onset of polycythemia vera and myelofibrosis disease hallmarks, respectively.

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Myeloproliferative neoplasms (MPNs) are driven by hyperactivation of JAK-STAT signaling but can demonstrate skewed hematopoiesis upon acquisition of additional somatic mutations. Here, using primary MPN samples and engineered embryonic stem cells, we demonstrate that mutations in JAK2 induced a significant increase in erythroid colony formation, whereas mutations in additional sex combs-like 1 (ASXL1) led to an erythroid colony defect. RNA-sequencing revealed upregulation of protein arginine methyltransferase 6 (PRMT6) induced by mutant ASXL1.

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Woolly mammoths in mainland Alaska overlapped with the region's first people for at least a millennium. However, it is unclear how mammoths used the space shared with people. Here, we use detailed isotopic analyses of a female mammoth tusk found in a 14,000-year-old archaeological site to show that she moved ~1000 kilometers from northwestern Canada to inhabit an area with the highest density of early archaeological sites in interior Alaska until her death.

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Depression is a common and devastating neuropsychiatric symptom in the elderly and in patients with dementia. In particular, nearly 80% of patients with Alzheimer's Disease dementia experience depression during disease development and progression. However, it is unknown whether the depression in patients with dementia shares the same molecular mechanisms as depression presenting as primary psychiatric disease or occurs and persists through alternative mechanisms.

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Platelets from patients with myeloproliferative neoplasms (MPNs) exhibit a hyperreactive phenotype. Here, we found elevated P-selectin exposure and platelet-leukocyte aggregates indicating activation of platelets from essential thrombocythemia (ET) patients. Single-cell RNA-seq analysis of primary samples revealed significant enrichment of transcripts related to platelet activation, mTOR, and oxidative phosphorylation in ET patient platelets.

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Mutations in the degradative ubiquitin ligase anaphase-promoting complex (APC) alter neurodevelopment by impairing proteasomal protein clearance, but our understanding of their molecular and cellular pathogenesis remains limited. Here, we employ the proteomic-based discovery of APC substrates in APC mutant mouse brain and human cell lines and identify the chromosome-passenger complex (CPC), topoisomerase 2a (Top2a), and Ki-67 as major chromatin factors targeted by the APC during neuronal differentiation. These substrates accumulate in phosphorylated form, suggesting that they fail to be eliminated after mitosis during terminal differentiation.

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Cell cycle transitions result from global changes in protein phosphorylation states triggered by cyclin-dependent kinases (CDKs). To understand how this complexity produces an ordered and rapid cellular reorganisation, we generated a high-resolution map of changing phosphosites throughout unperturbed early cell cycles in single Xenopus embryos, derived the emergent principles through systems biology analysis, and tested them by biophysical modelling and biochemical experiments. We found that most dynamic phosphosites share two key characteristics: they occur on highly disordered proteins that localise to membraneless organelles, and are CDK targets.

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Hyperactivation of JAK2 kinase is a unifying feature of human Ph- myeloproliferative neoplasms (MPNs), most commonly due to the JAK2 V617F mutation. Mice harboring a homologous mutation in the Jak2 locus exhibit a phenotype resembling polycythemia vera. NFκB pathway hyperactivation is present in myeloid neoplasms, including MPNs, despite scarcity of mutations in NFκB pathway genes.

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Histone post-translational modifications promote a chromatin environment that controls transcription, DNA replication and repair, but surprisingly few phosphorylations have been documented. We report the discovery of histone H3 serine-57 phosphorylation (H3S57ph) and show that it is implicated in different DNA repair pathways from fungi to vertebrates. We identified CHK1 as a major human H3S57 kinase, and disrupting or constitutively mimicking H3S57ph had opposing effects on rate of recovery from replication stress, 53BP1 chromatin binding, and dependency on RAD52.

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Bacterial species often undergo rampant recombination yet maintain cohesive genomic identity. Ecological differences can generate recombination barriers between species and sustain genomic clusters in the short term. But can these forces prevent genomic mixing during long-term coevolution? Cyanobacteria in Yellowstone hot springs comprise several diverse species that have coevolved for hundreds of thousands of years, providing a rare natural experiment.

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Background: Pathological amyloid-β and -synuclein are associated with a spectrum of related dementias, ranging from Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) to Parkinson disease dementia (PDD). While these diseases share clinical and pathological features, they also have unique patterns of pathology. However, epigenetic factors that contribute to these pathological differences remain unknown.

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  • Small molecule inhibitors targeting JAK2, like ruxolitinib and pacritinib, are primary treatments for myeloproliferative neoplasms (MPNs) and show varying effectiveness even though they all suppress JAK-STAT signaling.
  • In laboratory tests, all four studied inhibitors (including momelotinib) showed similar anti-proliferative effects, but pacritinib was particularly effective in reducing colony formation and extending survival in patient-derived models.
  • Analysis of gene activities revealed that the inhibitors differentially suppress JAK-STAT and inflammatory signaling, with pacritinib also impacting iron regulation, suggesting their distinct mechanisms could inform personalized treatment strategies for
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  • Scientists found hormones in elephant and mammoth tusks that show changes related to their reproduction and stress levels over time.
  • They used special testing methods to measure hormones in the tusks, and discovered that both the modern elephant and the ancient mammoth had similar mating behaviors called musth.
  • This research could help us learn more about how different animals grow and deal with stress, and it could also be useful in areas like medicine and archaeology.
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Ecological and evolutionary dynamics are intrinsically entwined. On short timescales, ecological interactions determine the fate and impact of new mutants, while on longer timescales evolution shapes the entire community. Here, we study the evolution of large numbers of closely related strains with generalized Lotka Volterra interactions but no niche structure.

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Literature has found that individuals with opioid use disorders have increased fasting insulin levels and that antagonism of the μ-receptor with naloxone blunted this hypoglycemic effect. We describe a 35-year-old woman with no history of diabetes who presented after being found unconscious where she was given naloxone and became awake and combative. Her blood glucose (BG) on presentation was 175 mg/dl, which declined to 40 mg/dl, and dextrose was administered.

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  • Researchers used FLIM-FRET microscopy to study the organization of nucleosome proximity, termed "nanocompaction," in living embryonic stem cells (ESCs) and epiblast-like cells (EpiLCs).
  • They found that heterochromatin is less compacted than expected, contradicting previous beliefs about chromatin structure.
  • Key factors influencing this low nanocompaction state include HP1 isoforms, the modification of histone H4 (specifically H4K20me2/3), and the presence of the Ki-67 protein.
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