1,182 research outputs found

    Discharge Identity of Medullary Inspiratory Neurons is Altered during Repetitive Fictive Cough

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    This study investigated the stability of the discharge identity of inspiratory decrementing (I-Dec) and augmenting (I-Aug) neurons in the caudal (cVRC) and rostral (rVRC) ventral respiratory column during repetitive fictive cough in the cat. Inspiratory neurons in the cVRC (n = 23) and rVRC (n = 17) were recorded with microelectrodes. Fictive cough was elicited by mechanical stimulation of the intrathoracic trachea. Approximately 43% (10 of 23) of I-Dec neurons shifted to an augmenting discharge pattern during the first cough cycle (C1). By the second cough cycle (C2), half of these returned to a decrementing pattern. Approximately 94% (16 of 17) of I-Aug neurons retained an augmenting pattern during C1 of a multi-cough response episode. Phrenic burst amplitude and inspiratory duration increased during C1, but decreased with each subsequent cough in a series of repetitive coughs. As a step in evaluating the model-driven hypothesis that VRC I-Dec neurons contribute to the augmentation of inspiratory drive during cough via inhibition of VRC tonic expiratory neurons that inhibit premotor inspiratory neurons, cross-correlation analysis was used to assess relationships of tonic expiratory cells with simultaneously recorded inspiratory neurons. Our results suggest that reconfiguration of inspiratory-related sub-networks of the respiratory pattern generator occurs on a cycle-by-cycle basis during repetitive coughing

    Spacetime Information

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    In usual quantum theory, the information available about a quantum system is defined in terms of the density matrix describing it on a spacelike surface. This definition must be generalized for extensions of quantum theory which do not have a notion of state on a spacelike surface. It must be generalized for the generalized quantum theories appropriate when spacetime geometry fluctuates quantum mechanically or when geometry is fixed but not foliable by spacelike surfaces. This paper introduces a four-dimensional notion of the information available about a quantum system's boundary conditions in the various sets of decohering histories it may display. The idea of spacetime information is applied in several contexts: When spacetime geometry is fixed the information available through alternatives restricted to a spacetime region is defined. The information available through histories of alternatives of general operators is compared to that obtained from the more limited coarse- grainings of sum-over-histories quantum mechanics. The definition of information is considered in generalized quantum theories. We consider as specific examples time-neutral quantum mechanics with initial and final conditions, quantum theories with non-unitary evolution, and the generalized quantum frameworks appropriate for quantum spacetime. In such theories complete information about a quantum system is not necessarily available on any spacelike surface but must be searched for throughout spacetime. The information loss commonly associated with the ``evolution of pure states into mixed states'' in black hole evaporation is thus not in conflict with the principles of generalized quantum mechanics.Comment: 47pages, 2 figures, UCSBTH 94-0

    Acute liver failure due to natural killer-like T-cell leukemia/lymphoma: A case report and review of the Literature

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    Acute liver failure (ALF) is a medical emergency requiring immediate evaluation for liver transplantation. We describe an unusual case of a patient who presented with ascites, jaundice, and encephalopathy and was found to have ALF due to natural killer (NK)-like T cell leukemia/lymphoma. The key immunophenotype was CD2+, CD3+, CD7+, CD56+. This diagnosis, which was based on findings in the peripheral blood and ascitic fluid, was confirmed with liver biopsy, and was a contraindication to liver transplantation. A review of the literature shows that hematologic malignancies are an uncommon cause of fulminant hepatic failure, and that NK-like T-cell leukemia/lymphoma is a relatively recently recognized entity which is characteristically CD3+ and CD56+. This case demonstrates that liver biopsy is essential in diagnosing unusual causes of acute liver failure, and that infiltration of the liver with NK-like T-cell lymphoma/leukemia can cause acute liver failure

    PGC-1 alpha induced mitochondrial biogenesis in stromal cells underpins mitochondrial transfer to melanoma

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    INTRODUCTION: Progress in the knowledge of metabolic interactions between cancer and its microenvironment is ongoing and may lead to novel therapeutic approaches. Until recently, melanoma was considered a glycolytic tumour due to mutations in mitochondrial-DNA, however, these malignant cells can regain OXPHOS capacity via the transfer of mitochondrial-DNA, a process that supports their proliferation in-vitro and in-vivo. Here we study how melanoma cells acquire mitochondria and how this process is facilitated from the tumour microenvironment. METHODS: Primary melanoma cells, and MSCs derived from patients were obtained. Genes’ expression and DNA quantification was analysed using Real-time PCR. MSC migration, melanoma proliferation and tumour volume, in a xenograft subcutaneous mouse model, were monitored through bioluminescent live animal imaging. RESULTS: Human melanoma cells attract bone marrow-derived stromal cells (MSCs) to the primary tumour site where they stimulate mitochondrial biogenesis in the MSCs through upregulation of PGC1a. Mitochondria are transferred to the melanoma cells via direct contact with the MSCs. Moreover, inhibition of MSC-derived PGC1a was able to prevent mitochondrial transfer and improve NSG melanoma mouse tumour burden. CONCLUSION: MSC mitochondrial biogenesis stimulated by melanoma cells is prerequisite for mitochondrial transfer and subsequent tumour growth, where targeting this pathway may provide an effective novel therapeutic approach in melanoma

    LUMINOS-102: Lerapolturev with and without α-PD- 1 in unresectable α-PD- 1 refractory melanoma

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    Lerapolturev (lera, formerly PVSRIPO) is a novel poliovirus based intratumoral immunotherapy that infects both cancer cells and antigen-presenting cells (APCs) via CD155, the poliovirus receptor. Lera has direct anticancer effects while also generating type I/III interferon-dominated inflammation and anti-tumor T-cell priming and activation via infection of local APCs. LUMINOS-102 (NCT04577807) is a multi-center, open-label, two-arm randomized Phase 2 study investigating the efficacy and safety of lera ± α-PD- 1 in patients with unresectable melanoma who failed prior α-PD- 1 therapy. Cross-over to the α-PD- 1 arm is permitted after progression, PR for ≥6 mo or 6 mo on treatment with SD. The maximum initial lera dose was 6x108 TCID50 /visit every 3 or 4 weeks (Q3/4 W). As of March 2022, the maximum lera dose was increased to 1.6 x 109 TCID50/visit, every week (QW) for 7 weeks (induction), followed by Q3/4 W dosing (maintenance). As of 20-Jun- 2022, 21 participants (10 male, 11 female, median 64 yrs) received lera (n = 14 at initial dose, Q3/4 W; n = 4 at increased dose, Q3/4 W; n = 3 at increased dose, QW) ± αPD-1. Five patients are currently on treatment. With the initial regimen, no objective responses and a CBR of 7% were observed. However, with the higher dose regimen, 1 complete response and a CBR of 71% (5/7) has been observed. Two of 4 participants with stable disease have evidence of response (1 with resolution of uninjected lung metastasis, 1 with decreased PET signal in injected and uninjected lesions receiving combination therapy). The only treatment related AE in \u3e1 pt was fatigue (19%, all grade 1 or 2). No dose-limiting toxicities or treatment-related SAEs were reported. Multiplex-IF analysis of on-treatment tumor biopsies will be presented. Lera ± αPD-1 is well tolerated, with early signs of efficacy at the higher dose level. Enrollment and randomization are ongoing

    Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

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    BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

    PGC-1α induced mitochondrial biogenesis in stromal cells underpins mitochondrial transfer to melanoma

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    Introduction: Progress in the knowledge of metabolic interactions between cancer and its microenvironment is ongoing and may lead to novel therapeutic approaches. Until recently, melanoma was considered a glycolytic tumour due to mutations in mitochondrial-DNA, however, these malignant cells can regain OXPHOS capacity via the transfer of mitochondrial-DNA, a process that supports their proliferation in-vitro and in-vivo. Here we study how melanoma cells acquire mitochondria and how this process is facilitated from the tumour microenvironment. Methods: Primary melanoma cells, and MSCs derived from patients were obtained. Genes’ expression and DNA quantification was analysed using Real-time PCR. MSC migration, melanoma proliferation and tumour volume, in a xenograft subcutaneous mouse model, were monitored through bioluminescent live animal imaging. Results: Human melanoma cells attract bone marrow-derived stromal cells (MSCs) to the primary tumour site where they stimulate mitochondrial biogenesis in the MSCs through upregulation of PGC1a. Mitochondria are transferred to the melanoma cells via direct contact with the MSCs. Moreover, inhibition of MSC-derived PGC1a was able to prevent mitochondrial transfer and improve NSG melanoma mouse tumour burden. Conclusion: MSC mitochondrial biogenesis stimulated by melanoma cells is prerequisite for mitochondrial transfer and subsequent tumour growth, where targeting this pathway may provide an effective novel therapeutic approach in melanoma

    Using Sequence Similarity Networks for Visualization of Relationships Across Diverse Protein Superfamilies

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    The dramatic increase in heterogeneous types of biological data—in particular, the abundance of new protein sequences—requires fast and user-friendly methods for organizing this information in a way that enables functional inference. The most widely used strategy to link sequence or structure to function, homology-based function prediction, relies on the fundamental assumption that sequence or structural similarity implies functional similarity. New tools that extend this approach are still urgently needed to associate sequence data with biological information in ways that accommodate the real complexity of the problem, while being accessible to experimental as well as computational biologists. To address this, we have examined the application of sequence similarity networks for visualizing functional trends across protein superfamilies from the context of sequence similarity. Using three large groups of homologous proteins of varying types of structural and functional diversity—GPCRs and kinases from humans, and the crotonase superfamily of enzymes—we show that overlaying networks with orthogonal information is a powerful approach for observing functional themes and revealing outliers. In comparison to other primary methods, networks provide both a good representation of group-wise sequence similarity relationships and a strong visual and quantitative correlation with phylogenetic trees, while enabling analysis and visualization of much larger sets of sequences than trees or multiple sequence alignments can easily accommodate. We also define important limitations and caveats in the application of these networks. As a broadly accessible and effective tool for the exploration of protein superfamilies, sequence similarity networks show great potential for generating testable hypotheses about protein structure-function relationships

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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