Fatigue Is Associated With Perceived Effort and 2-Dimensional Reach Performance After Stroke.

BACKGROUND AND PURPOSE: Poststroke fatigue (PSF) is prevalent and often manifests as high perceived effort during activities. Little is known about how PSF influences goal-directed reaching after stroke. The purpose of this study was 2-fold (1) to evaluate how perceived effort changed when individuals with stroke performed a reaching task with various demands and (2) to determine whether PSF was associated with perceived effort during reaching and reach performance. METHODS: Thirty-six individuals with chronic stroke performed 2-dimensional reach actions under varied conditions with the more and less affected arms. Perceived effort during reaching was assessed using rating of perceived exertion (RPE) and Paas Mental Effort Rating Scale (MERS). Derived reach kinematics were used to quantify reach performance. The Fatigue Severity Scale (FSS) was administered to assess fatigue severity. RESULTS: Perceived effort was higher when participants reached with the more affected arm, reached toward far and small targets, and performed memory-guided reaching. Both RPE and MERS significantly correlated with the FSS score (r = 0.50 and 0.35, respectively, P < 0.05). Further, FSS correlated with movement time during the more affected arm reaching (ρ = 0.40, p < 0.05) and reach performance discrepancy between the fast and self-selected speed conditions when participants performed with the less affected arm (ρ = 0.36, P < 0.05). Exploratory analysis revealed that the relationship between fatigue and reach control appeared to be modulated by task demand. DISCUSSION AND CONCLUSIONS: PSF is associated with perceived effort during reaching and reach performance after stroke. These relationships might offer insights into arm performance in the real world after stroke. VIDEO ABSTRACT: for more insights from the authors Supplemental Digital Content available at http://links.lww.com/JNPT/A476.

Disentangling top-down drivers of mortality underlying diel population dynamics of Prochlorococcus in the North Pacific Subtropical Gyre.

Photosynthesis fuels primary production at the base of marine food webs. Yet, in many surface ocean ecosystems, diel-driven primary production is tightly coupled to daily loss. This tight coupling raises the question: which top-down drivers predominate in maintaining persistently stable picocyanobacterial populations over longer time scales? Motivated by high-frequency surface water measurements taken in the North Pacific Subtropical Gyre (NPSG), we developed multitrophic models to investigate bottom-up and top-down mechanisms underlying the balanced control of Prochlorococcus populations. We find that incorporating photosynthetic growth with viral- and predator-induced mortality is sufficient to recapitulate daily oscillations of Prochlorococcus abundances with baseline community abundances. In doing so, we infer that grazers in this environment function as the predominant top-down factor despite high standing viral particle densities. The model-data fits also reveal the ecological relevance of light-dependent viral traits and non-canonical factors to cellular loss. Finally, we leverage sensitivity analyses to demonstrate how variation in life history traits across distinct oceanic contexts, including variation in viral adsorption and grazer clearance rates, can transform the quantitative and even qualitative importance of top-down controls in shaping Prochlorococcus population dynamics.

Comprehensive molecular-isotopic characterization of archaeal lipids in the Black Sea water column and underlying sediments.

The Black Sea is a permanently anoxic, marine basin serving as model system for the deposition of organic-rich sediments in a highly stratified ocean. In such systems, archaeal lipids are widely used as paleoceanographic and biogeochemical proxies; however, the diverse planktonic and benthic sources as well as their potentially distinct diagenetic fate may complicate their application. To track the flux of archaeal lipids and to constrain their sources and turnover, we quantitatively examined the distributions and stable carbon isotopic compositions (δ13 C) of intact polar lipids (IPLs) and core lipids (CLs) from the upper oxic water column into the underlying sediments, reaching deposits from the last glacial. The distribution of IPLs responded more sensitively to the geochemical zonation than the CLs, with the latter being governed by the deposition from the chemocline. The isotopic composition of archaeal lipids indicates CLs and IPLs in the deep anoxic water column have negligible influence on the sedimentary pool. Archaeol substitutes tetraether lipids as the most abundant IPL in the deep anoxic water column and the lacustrine methanic zone. Its elevated IPL/CL ratios and negative δ13 C values indicate active methane metabolism. Sedimentary CL- and IPL-crenarchaeol were exclusively derived from the water column, as indicated by non-variable δ13 C values that are identical to those in the chemocline and by the low BIT (branched isoprenoid tetraether index). By contrast, in situ production accounts on average for 22% of the sedimentary IPL-GDGT-0 (glycerol dibiphytanyl glycerol tetraether) based on isotopic mass balance using the fermentation product lactate as an endmember for the dissolved substrate pool. Despite the structural similarity, glycosidic crenarchaeol appears to be more recalcitrant in comparison to its non-cycloalkylated counterpart GDGT-0, as indicated by its consistently higher IPL/CL ratio in sediments. The higher TEX86 , CCaT, and GDGT-2/-3 values in glacial sediments could plausibly result from selective turnover of archaeal lipids and/or an archaeal ecology shift during the transition from the glacial lacustrine to the Holocene marine setting. Our in-depth molecular-isotopic examination of archaeal core and intact polar lipids provided new constraints on the sources and fate of archaeal lipids and their applicability in paleoceanographic and biogeochemical studies.

Proteomic Analyses of Plasma From Patients With Fracture-Related Infection Reveals Systemic Activation of the Complement and Coagulation Cascades.

OBJECTIVES: The objective of this study was to compare plasma proteomes of patients with confirmed fracture-related infections (FRIs) matched to noninfected controls using liquid chromatography-mass spectrometry. DESIGN: This was a prospective case-control study. SETTING: The study was conducted at a single, academic, Level 1 trauma center. PATIENT SELECTION CRITERIA: Patients meeting confirmatory FRI criteria were matched to controls without infection based on fracture region, age, and time after surgery from June 2019 to January 2022. Tandem mass tag liquid chromatography-mass spectrometry analysis of patient plasma samples was performed. OUTCOME MEASURES AND COMPARISONS: Protein abundance ratios in plasma for patients with FRI compared with those for matched controls without infection were calculated. RESULTS: Twenty-seven patients meeting confirmatory FRI criteria were matched to 27 controls. Abundance ratios for more than 1000 proteins were measured in the 54 plasma samples. Seventy-three proteins were found to be increased or decreased in patients with FRI compared with those in matched controls (unadjusted t test P < 0.05). Thirty-two of these proteins were found in all 54 patient samples and underwent subsequent principal component analysis to reduce the dimensionality of the large proteomics dataset. A 3-component principal component analysis accounted for 45.7% of the variation in the dataset and had 88.9% specificity for the diagnosis of FRI. STRING protein-protein interaction network analysis of these 3 PCs revealed activation of the complement and coagulation cascades through the Reactome pathway database (false discovery rates <0.05). CONCLUSIONS: Proteomic analyses of plasma from patients with FRI demonstrate systemic activation of the complement and coagulation cascades. Further investigation along these lines may help to better understand the systemic response to FRI and improve diagnostic strategies using proteomics. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Validating the Fatigue Scale for Motor and Cognitive Function (FSMC) in chronic stroke.

BACKGROUND: Post-stroke fatigue can manifest as both physical and mental fatigue. The Fatigue Scale for Motor and Cognitive Functions (FSMC) evaluates fatigue on the motor and cognitive domains separately, however, the psychometric properties of this measure in stroke have not been reported. OBJECTIVE: To determine the internal consistency, test-retest reliability, and concurrent validity of the FSMC in chronic stroke. METHODS: Thirty-four participants with chronic stroke (55.26±12.27 years of age; 59.53±89.21 months post-stroke) completed the FSMC on two separate visits. Internal consistency and reliability of the FSMC were examined using Cronbach's alpha and two-way mixed effects intraclass correlation coefficients (ICC), respectively. Correlation between the FSMC and the Fatigue Severity Scale and Visual Analog Scale-Fatigue was used to assess concurrent validity. RESULTS: Internal consistency was excellent (Cronbach's alpha > 0.9) and reliability was moderate to good (ICC = 0.72-0.81) for all FSMC scores. The FSMC demonstrated moderate to good concurrent validity with the Fatigue Severity Scale (ρ= 0.66-0.72) but only fair concurrent validity with the Visual Analog Scale-Fatigue (ρ= 0.37-0.44). CONCLUSION: The FSMC is a valid and reliable measure of post-stroke fatigue and may be a useful tool to examine physical fatigue and cognitive fatigue in chronic stroke.

Genomic characterization of an esthesioneuroblastoma with spinal metastases: illustrative case.

BACKGROUND: Esthesioneuroblastoma (ENB) is a rare neoplasm of the sinonasal tract. Currently, the optimal treatment includes maximal resection combined with radiotherapy and/or chemotherapy. Although ENBs often recur and have an aggressive clinical course, spinal metastases are extremely rare and the underlying molecular mechanisms are poorly understood. OBSERVATIONS: Here, the authors describe a 50-year-old male with an aggressive ENB, initially treated with resection and chemotherapy/radiation, who developed multiple thoracic and lumbar spinal metastases. The authors performed targeted exome sequencing on both the resected primary tumor and biopsied spinal metastases, which revealed 12 total variants of unknown clinical significance in genes associated with the PI3K/AKT/mTOR pathway, chromatin remodeling, DNA repair, and cell proliferation. Six of these variants were restricted to the metastatic lesion and included missense mutations with predicted functional effects in GRM3, DNMT3B, PLCG2, and SPEN. LESSONS: This report discusses the potential impact of these variants on tumor progression and metastasis, as well as the implications for identifying potential new biomarkers and therapies.

Transcriptional changes in the rat brain induced by repetitive transcranial magnetic stimulation.

Introduction: Transcranial Magnetic Stimulation (TMS) is a noninvasive technique that uses pulsed magnetic fields to affect the physiology of the brain and central nervous system. Repetitive TMS (rTMS) has been used to study and treat several neurological conditions, but its complex molecular basis is largely unexplored. Methods: Utilizing three experimental rat models (in vitro, ex vivo, and in vivo) and employing genome-wide microarray analysis, our study reveals the extensive impact of rTMS treatment on gene expression patterns. Results: These effects are observed across various stimulation protocols, in diverse tissues, and are influenced by time and age. Notably, rTMS-induced alterations in gene expression span a wide range of biological pathways, such as glutamatergic, GABAergic, and anti-inflammatory pathways, ion channels, myelination, mitochondrial energetics, multiple neuron-and synapse-specific genes. Discussion: This comprehensive transcriptional analysis induced by rTMS stimulation serves as a foundational characterization for subsequent experimental investigations and the exploration of potential clinical applications.

Rapid discovery of terpene tailoring enzymes for total biosynthesis.

Twenty oxygenated aristolochene congeners were rapidly synthesised by combining genes from four different fungal pathways in the fungal host organism Aspergillus oryzae. Compounds produced in a single step include the natural product hypoxylan A and an epimer of guignaderemophilane C. A new fungal aromatase was discovered that produces phenols by oxidative demethylation.

Sporothioethers: deactivated alkyl citrates from the fungus Hypomontagnella monticulosa.

Submerged cultivation of Hypomontagnella monticulosa MUCL 54604 resulted in formation of a stereoisomeric mixture of new sulfur-containing sporothriolide derivatives named sporothioethers A and B. The presence of the 2-hydroxy-3-mercaptopropanoic acid moiety attenuates the antimicrobial activity in comparison to the precursor sporothriolide suggesting a detoxification mechanism. However, moderate effects on biofilms of Candida albicans and Staphylococcus aureus were observed for sporothriolide and sporothioethers A and B at concentrations below their MICs.

Sequential Early-Life Infections Alter Peripheral Blood Transcriptomics in Aging Female Mice but Not the Response to De Novo Infection with Influenza Virus or M. tuberculosis.

To determine the impact of accumulating Ag exposure on immunity in the aging mouse, and to develop a model more relevant to humans who are exposed to multiple pathogens during life, we sequentially infected young female mice with four distinct pathogens at 8-wk intervals: murine γ-herpesvirus 68, Sendai virus, murine CMV, and Heligmosomoides polygyrus. Mock-infected mice received PBS. After aging the sequentially infected and mock-infected mice to 18-25 mo under specific pathogen-free conditions, we analyzed multiple immune parameters. We assessed transcriptional activity in peripheral blood, T cell phenotype, the diversity of influenza epitopes recognized by CD8 T cells, and the response of the animals to infection with influenza virus and Mycobacterium tuberculosis. Our data show enhanced transcriptional activation in sequentially infected aged mice, with changes in some CD8 T cell subsets. However, there was no measurable difference in the response of mock-infected and sequentially infected aged mice to de novo infection with either influenza virus or M. tuberculosis at 18-21 mo. Unexpectedly, a single experiment in which 25-mo-old female mice were challenged with influenza virus revealed a significantly higher survival rate for sequentially infected (80%) versus mock-infected (20%) mice. These data suggest that although exposure to a variety of pathogen challenges in the mouse model does not overtly impact cellular markers of immunity in aged female mice following de novo respiratory infection, subtle changes may emerge in other compartments or with increasing age.

NF-κB subunits direct kinetically distinct transcriptional cascades in antigen receptor-activated B cells.

The nuclear factor kappa B (NF-κB) family of transcription factors orchestrates signal-induced gene expression in diverse cell types. Cellular responses to NF-κB activation are regulated at the level of cell and signal specificity, as well as differential use of family members (subunit specificity). Here we used time-dependent multi-omics to investigate the selective functions of Rel and RelA, two closely related NF-κB proteins, in primary B lymphocytes activated via the B cell receptor. Despite large numbers of shared binding sites genome wide, Rel and RelA directed kinetically distinct cascades of gene expression in activated B cells. Single-cell RNA sequencing revealed marked heterogeneity of Rel- and RelA-specific responses, and sequential binding of these factors was not a major mechanism of protracted transcription. Moreover, nuclear co-expression of Rel and RelA led to functional antagonism between the factors. By rigorously identifying the target genes of each NF-κB subunit, these studies provide insights into exclusive functions of Rel and RelA in immunity and cancer.

Establishing a rapid assessment service for patients with suspected malignancies for expedited outpatient management.

BACKGROUND: 11% of new cancer diagnoses occur in the emergency department. Historically, these diagnoses disproportionately affect underserved patient populations and are associated with poor outcomes. This is an observational study of the Rapid Assessment Service (RAS) program, which aims to provide timely outpatient follow-up and facilitate a diagnosis for patients discharged from the emergency department with suspected malignancies. METHODS: We performed a retrospective chart review of 176 patients who were discharged from the emergency department with RAS clinic follow up between February 2020 and March 2022. We manually chart reviewed 176 records in order to determine the average time to RAS clinic appointment, average time to diagnosis, and the final diagnosis based on biopsy. RESULTS: 163 of 176 patients (93%) discharged to RAS received reliable follow-up care. 62 of the 176 patients (35%) followed up in the RAS clinic with a mean of 4.6 days. 46 of the 62 patients (74%) who followed up in the RAS clinic were ultimately diagnosed with a new cancer, with a mean time to diagnosis of 13.5 days. The leading new cancer diagnoses included: lung, ovarian, hematologic, head and neck, and renal cancers. CONCLUSIONS: Creating a Rapid Assessment Service facilitated an expedited oncologic work-up and diagnosis in an outpatient setting.

DNA methylation provides diagnostic value for meningioma recurrence in clinical practice.

BACKGROUND: Meningiomas are the most common intracranial tumors. Recent advancements in the genetic profiling of tumors have allowed information including DNA copy number analysis, mutational analysis, and RNA sequencing to be more frequently reported, in turn allowing better characterization of meningiomas. In recent years, analysis of tumor methylomes that reflects both cell-origin methylation signatures and somatically acquired DNA methylation changes has been utilized to better classify meningiomas with great success. METHOD: We report DNA methylation profiling on meningiomas from 17 patients. Formalin-fixed paraffin-embedded (FFPE) meningioma tumor samples were processed, loaded onto the Infinium Methylation EPIC array, and scanned using the Illumina IScan system. Raw IDAT files were processed through the the CNS tumor classifier developed by the Molecular Neuropathology group at the German Cancer Research Center (DKFZ). Corresponding genomics were captured using targeted sequencing panels. RESULT: Among the meningioma samples, 13 samples were classified as "benign," two samples as "intermediate," and the remaining three samples (from two patients) as "malignant," based on previously validated classification algorithms. In addition to tumor methylation profiling, we also present information that includes patient demographics, clinical presentations, tumor characteristics (including size and location), surgical approaches, and mutational analysis. The two patients who provided the samples with "malignant" methylation classifications had tumor recurrence, reflecting a more aggressive disease course. CONCLUSION: In accordance with prior reports, our case series provides support that tumor DNA methylation profiling adds meaningful classification information and may be beneficial to incorporate in clinical practice. Our report also reveals that DNA methylation combined with WHO histology classification can more accurately predict tumor behavior than WHO classification alone.

The Absence of Vision Impacts Attentional Focus Effects During a Balancing Task.

Purpose: Recent work involving reaching and aiming tasks provides evidence that an internal focus results in less error than an external focus when visual information is removed. The purpose of this study was to extend these findings by determining how an internal and external focus impact motor performance during a balancing task for adults with and without visual occlusion. Method: Thirty-two undergraduate students were randomly assigned to perform the task with or without visual occlusion. Participants balanced on a stability platform during four familiarization trials, three internal focus trials, and three external focus trials. Results: A significant Focus x Vision interaction indicated the group without visual occlusion had significantly lower root mean square error (RMSE) with an external focus, whereas the group with visual occlusion had lower RMSE with an internal focus. Conclusions: These findings indicate that for tasks that rely on online sensory feedback, such as balancing, the optimal attentional focus may be dependent on the dominant type of sensory feedback that is available.

Utilising an internal focus of attention during preparation and an external focus during execution may facilitate motor learning.

Research with athletes and coaches has found that attentional focus strategies are more complex than using an internal or external focus exclusively. Recently Becker et al. [2020, March 1. The effects of attentional focus in the preparation and execution of a standing long jump. Psychological Research, 84(2), 285-291] found that switching attentional focus from internal in movement preparation to external during movement execution provided a benefit over internal focus and control conditions. The purpose of this study was to investigate the effects of attentional switching on motor skill acquisition. 79 participants were randomly divided into an internal (INT), external (EXT), or switching group (IES). Individuals performed 80 acquisition trials of a golf chipping task with their prescribed attentional focus during preparation and execution. 24-hours later 10-trial retention and transfer tests were performed. The primary analysis revealed significant improvement during acquisition (p < .001) but no significant differences between attentional focus groups during acquisition, retention, or transfer. A secondary analysis was performed with individuals low in attentional focus adherence removed (<60%). Groups significantly improved during acquisition (p < .001). For retention IES significantly outperformed INT (p < .05). These results suggest that the detrimental effects of an internal focus are only found during skill execution and not movement preparation. It is possible for learners to benefit from both an internal and external focus so long as the cues are provided during the correct phase of skill performance.Highlights Attentional focus is much more complex than using either an internal or external focus of attention. This study investigated the effects of switching attention during skill acquisition from an internal to external focus.A preliminary analysis revealed no significant differences between attentional focus groups of internal, external, or switching. One reason for this finding was the poor adherence to the prescribed focus cue.A secondary analysis where low adherence individuals were removed revealed a significant difference between the switching group and the internal focus group during retention.These finding suggest that the detrimental effects associated with an internal focus of attention are exclusive to using the focus during task execution. It is possible that an internal focus can still facilitate learning so long as an external focus is used during movement execution.

Memory-Guided Reaching: Is It Effortful?

We previously showed that perceived effort during visually guided reaching was altered as task demand varied. Further, self-reported subjective fatigue correlated with perceived effort and reach performance under visually guided conditions. Memory-guided reaching often leads to performance deterioration and can provide insights about the planning and control of reach actions. It is unclear how perceived effort changes during memory-guided reaching and whether self-reported subjective fatigue is associated with perceived effort of memory-guided reaching. Twenty-three young adults performed reach actions under visually- and memory-guided conditions. Perceived effort, reaction time, and endpoint error increased significantly from the visually- to the memory-guided condition. Self-reported subjective fatigue was associated with perceived effort and reach distance error during memory-guided reaching; those with higher levels of fatigue reported greater perceived effort and tended to reach farther when visual information was not available. These findings establish a foundation to examine relationships between subjective fatigue, perceived effort, and reach control.

Spinal Lymphoma Presenting as an Epidural and Retropleural Mass With Concomitant Pathologic Compression Fracture: A Case Report.

Lymphoma has traditionally earned the nickname "the great mimicker". Its presentation as a primary spinal tumor is rare, and therefore seldom included in the differential diagnosis. However, its mimicking nature and diverse presentation make it very difficult to exclude entirely. Here, we present an elderly patient with histology-confirmed spinal lymphoma presenting as both an epidural mass with transforaminal extension into the retropleural space as well as vertebral body compression fracture, together leading to severe spinal stenosis and compressive myelopathy. Additional non-malignant compression fractures found in our patient allow for an interesting discussion on disease presentation and imaging-based diagnosis. We discuss our approach to diagnosis, surgical treatment, and post-operative medical care.

Pilocytic Astrocytoma Arising from the Conus Medullaris in an Adult: A Case Report.

Low-grade, sporadic, pilocytic astrocytomas (PAs) are rare spinal cord tumors diagnosed in adult patients. Their localization to the conus medullaris is exceedingly rare, having only been described in a limited number of case reports. Here, we describe a case of a 22-year-old female presenting with back pain, lower extremity weakness, hypoesthesia, and urinary incontinence. Imaging studies demonstrated a cystic lesion of the conus medullaris that was treated with subtotal resection and cyst-subarachnoid shunt placement. Final pathology report confirmed PA from the histology of surgical specimens. We discuss the current literature of conus medullaris lesions and their differential diagnosis.

Aberrant expression and localization of the RAP1 shelterin protein contribute to age-related phenotypes.

Short telomeres induce a DNA damage response (DDR) that evokes apoptosis and senescence in human cells. An extant question is the contribution of telomere dysfunction-induced DDR to the phenotypes observed in aging and telomere biology disorders. One candidate is RAP1, a telomere-associated protein that also controls transcription at extratelomeric regions. To distinguish these roles, we generated a knockin mouse carrying a mutated Rap1, which was incapable of binding telomeres and did not result in eroded telomeres or a DDR. Primary Rap1 knockin embryonic fibroblasts showed decreased RAP1 expression and re-localization away from telomeres, with an increased cytosolic distribution akin to that observed in human fibroblasts undergoing telomere erosion. Rap1 knockin mice were viable, but exhibited transcriptomic alterations, proinflammatory cytokine/chemokine signaling, reduced lifespan, and decreased healthspan with increased body weight/fasting blood glucose levels, spontaneous tumor incidence, and behavioral deficits. Taken together, our data present mechanisms distinct from telomere-induced DDR that underlie age-related phenotypes.

Nicotinamide adenine dinucleotide supplementation drives gut microbiota variation in Alzheimer's mouse model.

Alzheimer's disease (AD) is the most common neurodegenerative disease. Growing evidence suggests an important role for gut dysbiosis and gut microbiota-host interactions in aging and neurodegeneration. Our previous works have demonstrated that supplementation with the nicotinamide adenine dinucleotide (NAD+) precursor, nicotinamide riboside (NR), reduced the brain features of AD, including neuroinflammation, deoxyribonucleic acid (DNA) damage, synaptic dysfunction, and cognitive impairment. However, the impact of NR administration on the intestinal microbiota of AD remains unknown. In this study, we investigated the relationship between gut microbiota and NR treatment in APP/PS1 transgenic (AD) mice. Compared with wild type (WT) mice, the gut microbiota diversity in AD mice was lower and the microbiota composition and enterotype were significantly different. Moreover, there were gender differences in gut microbiome between female and male AD mice. After supplementation with NR for 8 weeks, the decreased diversity and perturbated microbial compositions were normalized in AD mice. This included the species Oscillospira, Butyricicoccus, Desulfovibrio, Bifidobacterium, Olsenella, Adlercreutzia, Bacteroides, Akkermansia, and Lactobacillus. Our results indicate an interplay between NR and host-microbiota in APP/PS1 mice, suggesting that the effect of NR on gut dysbiosis may be an important component in its therapeutic functions in AD.