90 results on '"Howard RM"'
Search Results
2. Memory Category Fluency, Memory Specificity, and the Fading Affect Bias for Positive and Negative Autobiographical Events: Performance on a Good Day- Bad Day Task in Healthy and Depressed Individuals
- Author
-
Hitchcock, C, Newby, J, Timm, E, Howard, RM, Golden, AM, Kuyken, W, Dalgleish, T, Hitchcock, Caitlin [0000-0002-2435-0713], Dalgleish, Tim [0000-0002-7304-2231], and Apollo - University of Cambridge Repository
- Subjects
Adult ,Male ,Affect ,Depressive Disorder ,Memory, Episodic ,Mental Recall ,Humans ,Female ,psychological phenomena and processes - Abstract
In mentally healthy individuals, autobiographical memory is typically biased toward positive events, which may help to maintain psychological well-being. Our aim was to assess a range of important positive memory biases in the mentally healthy and explore the possibility that these biases are mitigated in those with mental health problems. We administered a novel recall paradigm that required recollection of multiple good and bad past events (the Good Day-Bad Day task) to healthy and depressed individuals. This allowed us to explore differences in memory category fluency (i.e., the ability to generate integrated sets of associated events) for positive and negative memories, along with memory specificity, and fading affect bias-a greater reduction in the intensity of memory-related affect over time for negative versus positive events. We found that healthy participants demonstrated superior category fluency for positive relative to negative events but that this effect was absent in depressed participants. Healthy participants exhibited a strong fading affect bias that was significantly mitigated, although still present, in depression. Finally, memory specificity was reduced in depression for both positive and negative memories. Findings demonstrate that the positive bias associated with mental health is maintained by multiple autobiographical memory processes and that depression is as much a function of the absence of these positive biases as it is the presence of negative biases. Results provide important guidance for developing new treatments for improving mental health.
- Published
- 2020
3. Affective enhancement of working memory is maintained in depression
- Author
-
Schweizer, S ; https://orcid.org/0000-0001-6153-8291, Navrady, L, Breakwell, L, Howard, RM, Golden, AM, Werner-Seidler, A ; https://orcid.org/0000-0002-9046-6159, Dalgleish, T, Schweizer, S ; https://orcid.org/0000-0001-6153-8291, Navrady, L, Breakwell, L, Howard, RM, Golden, AM, Werner-Seidler, A ; https://orcid.org/0000-0002-9046-6159, and Dalgleish, T
- Abstract
We currently know little about how performance on assessments of working memory capacity (WMC) that are designed to mirror the concurrent task demands of daily life are impacted by the presence of affective information, nor how those effects may be modulated by depression-a syndrome where sufferers report global difficulties with executive processing. Across 3 experiments, we investigated WMC for sets of neutral words in the context of processing either neutral or affective (depressogenic) sentences, which had to be judged on semantic accuracy (Experiments 1 and 2) or self-reference (Experiment 3). Overall, WMC was significantly better in the context of depressogenic compared with neutral sentences. However, there was no support for this effect being modulated by symptoms of depression (Experiment 1) or the presence of recurrent major depressive disorder (MDD; Experiments 2 and 3). Implications of these findings for cognitive theories of the role ofWMin depression are discussed in the context of a growing body of research showing no support for a differential impact of depressogenic compared with neutral information on WM accuracy.
- Published
- 2018
4. Effects of Propeller Slipstream on Wing Laminar Boundary Layer
- Author
-
Australian Aeronautical Conference (3rd : 1989 : Melbourne, Vic.), Miley, SJ, and Howard, RM
- Published
- 1989
5. Intertextuality in the transcultural contact zone
- Author
-
Howard, RM, Robillard, A, Thompson, CH, Pennycook, AD, Howard, RM, Robillard, A, Thompson, CH, and Pennycook, AD
- Published
- 2008
6. Bullous 'cellulitis' with eosinophilia: case report and review of Wells' syndrome in childhood.
- Author
-
Gilliam AE, Bruckner AL, Howard RM, Lee BP, Wu S, and Frieden IJ
- Published
- 2005
- Full Text
- View/download PDF
7. Intertextuality in the transcultural contact zone
- Author
-
Thompson, CH, Pennycook, AD, Howard, RM, and Robillard, A
- Published
- 2008
8. GSDMD Deficiency Attenuates the Development of Ascending Aortic Dissections in a Novel Mouse Model.
- Author
-
Javed MJ, Howard RM, Li H, Carrasco L, Dirain MLS, Su G, Cai G, Upchurch GR Jr, and Jiang Z
- Abstract
Background: Mechanisms driving the development of type A aortic dissection (TAD) are currently poorly understood, and animal models of spontaneous TAD are limited. In the present study, we developed a novel mouse TAD model and evaluated the role of GSDMD (gasdermin D) in TAD development., Methods: TADs were created by treating the ascending aorta of adult C57BL/6J mice with Act E (active elastase) and β-aminopropionitrile. The temporal progress of the TAD pathology was rigorously characterized by histological evaluation and scanning electron microscopy, while potential mechanisms were explored using bulk RNA sequencing of specimens collected at multiple time points. With this novel TAD model, we conducted additional experiments to investigate the impact of GSDMD deficiency on TAD formation., Results: Ascending aortas challenged with Act E and β-aminopropionitrile developed pathology featuring the early onset of intimomedial tears (complete penetration) and intramural hematomas, followed by progressive medial loss and aortic dilation. Ingenuity pathway analysis and functional annotation of differentially expressed genes suggested that a unique inflammatory microenvironment, rather than general inflammation, promotes the onset of TADs by specifically recruiting neutrophils to the aortic wall. At later stages, T cell-mediated immune injury emerged as the primary driver of pathology. Gsdmd deficiency attenuated medial loss, adventitial fibrosis, and dilation of TADs. This protective effect correlated with a reduced cell death and decreased T-cell infiltration in TADs. Notably, cleaved GSDMD was detected in human TADs but was absent in healthy aortas., Conclusions: A novel mouse TAD model was developed, specifically targeting the ascending aorta. This model generates a unique microenvironment that activates specific immune cell subsets, driving the onset and subsequent remodeling of TADs. Consistently, Gsdmd deficiency mitigates TAD development, likely by modulating cell death and T-cell responses. This model provides a valuable tool for studying immune injury mechanisms in TAD pathogenesis.
- Published
- 2025
- Full Text
- View/download PDF
9. Reduced White Matter Damage and Lower Neuroinflammatory Potential of Microglia and Macrophages in Hri/Eif2ak1 -/- Mice After Contusive Spinal Cord Injury.
- Author
-
Saraswat Ohri S, Myers SA, Rood B, Brown BL, Chilton PM, Slomnicki L, Liu Y, Wei GZ, Andres KR, Mohan D, Howard RM, Whittemore SR, and Hetman M
- Abstract
Cellular stressors inhibit general protein synthesis while upregulating stress response transcripts and/or proteins. Phosphorylation of the translation factor eIF2α by one of the several stress-activated kinases is a trigger for such signaling, known as the integrated stress response (ISR). The ISR regulates cell survival and function under stress. Here, germline knockout mice were used to determine contributions by three major ISR kinases, HRI/EIF2AK1, GCN2/EIF2AK4, and PKR//EIF2AK2, to pathogenesis of moderate contusive spinal cord injury (SCI) at the thoracic T9 level. One-day post-injury (dpi), reduced levels of peIF2α were found in Hri
-/- and Gcn2-/- , but not in Pkr-/- mice. In addition, Hri-/- mice showed attenuated expression of the downstream ISR transcripts, Atf4 or Chop. Such differential effects of SCI-activated ISR correlated with a strong or moderate enhancement of locomotor recovery in Hri-/- or Gcn2-/- mice, respectively. Hri-/- mice also showed reduced white matter loss, increased content of oligodendrocytes (OL) and attenuated neuroinflammation, including decreased lipid accumulation in microglia/macrophages. Cultured neonatal Hri-/- OLs showed lower ISR cytotoxicity. Moreover, cell autonomous reduction in neuroinflammatory potential was observed in microglia and bone marrow-derived macrophages derived from Hri-/- mice. These data identify HRI as a major positive regulator of SCI-associated secondary injury. In addition, targeting HRI may enable multimodal neuroprotection to enhance functional recovery after SCI., (© 2025 Wiley Periodicals LLC.)- Published
- 2025
- Full Text
- View/download PDF
10. Gasdermin D deficiency attenuates development of ascending aortic dissections in a novel mouse model.
- Author
-
Javed MJ, Howard RM, Li H, Carrasco L, Dirain MLS, Su G, Cai G, Upchurch GR, and Jiang Z
- Abstract
Background: Thoracic aortic dissection (TAD) is a silent killer. Approximately two-thirds of the cases occur in the ascending aorta (i.e. type A dissection) and majority of them are unrelated to genetic mutations. However, animal models of spontaneous type A dissection are not widely available. In the present study, a novel mouse TAD model was created. Further, the role of gasdermin D (GSDMD) in TAD development was evaluated., Methods: TADs were created by treating ascending aorta of adult mice (C57BL/6J) with active elastase (40.0 U/ml) and β-aminopropionitrile (Act E+BAPN). The temporal progress of the TAD pathology was rigorously characterized by histological evaluation and scanning electron microscopy, while potential mechanisms explored with bulk RNA sequencing of specimens collected at multiple timepoints. With this novel TAD model, further experiments were performed with Gsdmd
-/- mice to evaluate its impact on TAD formation., Results: The ascending aorta challenged with Act E+BAPN developed pathology characterized by an early onset of intimomedial tears (complete penetration) and intramural hematoma, followed by progressive medial loss and aortic dilation. Ingenuity Pathway Analysis and functional annotation of differentially expressed genes suggested that a unique inflammatory micro-environment, rather than general inflammation, promoted the onset of TADs by specifically recruiting neutrophils to the aortic wall, while the pathology at the advanced stage was driven by T-cell mediated immune injury. Gsdmd-/- attenuated medial loss, adventitial fibrosis, and dilation of TADs. This protective effect was associated with a reduced number of TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) positive cells and T-cells in TADs., Conclusions: A novel mouse TAD model was created in the ascending aorta. It produces a unique microenvironment to activate different immune cell subsets, promoting onset and subsequent remodeling of TADs. Consistently, Gsdmd-/- attenuates TAD development, with modulation of cell death and T-cell response likely acting as the underlying mechanism.- Published
- 2024
- Full Text
- View/download PDF
11. Oligodendrocyte-selective deletion of the eIF2α kinase Perk/Eif2ak3 limits functional recovery after spinal cord injury.
- Author
-
Saraswat Ohri S, Forston MD, Myers SA, Brown BL, Andres KR, Howard RM, Gao Y, Liu Y, Cavener DR, Hetman M, and Whittemore SR
- Subjects
- Animals, Mice, Mice, Transgenic, Female, Disease Models, Animal, Mice, Inbred C57BL, Spinal Cord Injuries metabolism, Spinal Cord Injuries genetics, Spinal Cord Injuries pathology, Oligodendroglia metabolism, eIF-2 Kinase metabolism, eIF-2 Kinase genetics, Recovery of Function physiology
- Abstract
After spinal cord injury (SCI), re-establishing cellular homeostasis is critical to optimize functional recovery. Central to that response is PERK signaling, which ultimately initiates a pro-apoptotic response if cellular homeostasis cannot be restored. Oligodendrocyte (OL) loss and white matter damage drive functional consequences and determine recovery potential after thoracic contusive SCI. We examined acute (<48 h post-SCI) and chronic (6 weeks post-SCI) effects of conditionally deleting Perk from OLs prior to SCI. While Perk transcript is expressed in many types of cells in the adult spinal cord, its levels are disproportionately high in OL lineage cells. Deletion of OL-Perk prior to SCI resulted in: (1) enhanced acute phosphorylation of eIF2α, a major PERK substrate and the critical mediator of the integrated stress response (ISR), (2) enhanced acute expression of the downstream ISR genes Atf4, Ddit3/Chop, and Tnfrsf10b/Dr5, (3) reduced acute OL lineage-specific Olig2 mRNA, but not neuronal or astrocytic mRNAs, (4) chronically decreased OL content in the spared white matter at the injury epicenter, (5) impaired hindlimb locomotor recovery, and (6) reduced chronic epicenter white matter sparing. Cultured primary OL precursor cells with reduced PERK expression and activated ER stress response showed: (1) unaffected phosphorylation of eIF2α, (2) enhanced ISR gene induction, and (3) increased cytotoxicity. Therefore, OL-Perk deficiency exacerbates ISR signaling and potentiates white matter damage after SCI. The latter effect is likely mediated by increased loss of Perk
-/- OLs., (© 2024 Wiley Periodicals LLC.)- Published
- 2024
- Full Text
- View/download PDF
12. Probing the chemical 'reactome' with high-throughput experimentation data.
- Author
-
King-Smith E, Berritt S, Bernier L, Hou X, Klug-McLeod JL, Mustakis J, Sach NW, Tucker JW, Yang Q, Howard RM, and Lee AA
- Abstract
High-throughput experimentation (HTE) has the potential to improve our understanding of organic chemistry by systematically interrogating reactivity across diverse chemical spaces. Notable bottlenecks include few publicly available large-scale datasets and the need for facile interpretation of these data's hidden chemical insights. Here we report the development of a high-throughput experimentation analyser, a robust and statistically rigorous framework, which is applicable to any HTE dataset regardless of size, scope or target reaction outcome, which yields interpretable correlations between starting material(s), reagents and outcomes. We improve the HTE data landscape with the disclosure of 39,000+ previously proprietary HTE reactions that cover a breadth of chemistry, including cross-coupling reactions and chiral salt resolutions. The high-throughput experimentation analyser was validated on cross-coupling and hydrogenation datasets, showcasing the elucidation of statistically significant hidden relationships between reaction components and outcomes, as well as highlighting areas of dataset bias and the specific reaction spaces that necessitate further investigation., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
13. Reduced Expression of Oligodendrocyte Linage-Enriched Transcripts During the Endoplasmic Reticulum Stress/Integrated Stress Response.
- Author
-
Gao Y, Slomnicki LP, Kilanczyk E, Forston MD, Pietrzak M, Rouchka EC, Howard RM, Whittemore SR, and Hetman M
- Subjects
- Animals, Rats, Mice, Thapsigargin pharmacology, Rats, Sprague-Dawley, Mice, Inbred C57BL, Transcriptome, Cells, Cultured, Female, Endoplasmic Reticulum Stress physiology, Endoplasmic Reticulum Stress drug effects, Oligodendroglia metabolism, Oligodendroglia drug effects, Tunicamycin pharmacology
- Abstract
Endoplasmic reticulum (ER) stress in oligodendrocyte (OL) linage cells contributes to several CNS pathologies including traumatic spinal cord injury (SCI) and multiple sclerosis. Therefore, primary rat OL precursor cell (OPC) transcriptomes were analyzed using RNASeq after treatments with two ER stress-inducing drugs, thapsigargin (TG) or tunicamycin (TM). Gene ontology term (GO) enrichment showed that both drugs upregulated mRNAs associated with the general stress response. The GOs related to ER stress were only enriched for TM-upregulated mRNAs, suggesting greater ER stress selectivity of TM. Both TG and TM downregulated cell cycle/cell proliferation-associated transcripts, indicating the anti-proliferative effects of ER stress. Interestingly, many OL lineage-enriched mRNAs were downregulated, including those for transcription factors that drive OL identity such as Olig2 . Moreover, ER stress-associated decreases of OL-specific gene expression were found in mature OLs from mouse models of white matter pathologies including contusive SCI, toxin-induced demyelination, and Alzheimer's disease-like neurodegeneration. Taken together, the disrupted transcriptomic fingerprint of OL lineage cells may facilitate myelin degeneration and/or dysfunction when pathological ER stress persists in OL lineage cells.
- Published
- 2024
- Full Text
- View/download PDF
14. Parallel multi-droplet platform for reaction kinetics and optimization.
- Author
-
Eyke NS, Schneider TN, Jin B, Hart T, Monfette S, Hawkins JM, Morse PD, Howard RM, Pfisterer DM, Nandiwale KY, and Jensen KF
- Abstract
We present an automated droplet reactor platform possessing parallel reactor channels and a scheduling algorithm that orchestrates all of the parallel hardware operations and ensures droplet integrity as well as overall efficiency. We design and incorporate all of the necessary hardware and software to enable the platform to be used to study both thermal and photochemical reactions. We incorporate a Bayesian optimization algorithm into the control software to enable reaction optimization over both categorical and continuous variables. We demonstrate the capabilities of both the preliminary single-channel and parallelized versions of the platform using a series of model thermal and photochemical reactions. We conduct a series of reaction optimization campaigns and demonstrate rapid acquisition of the data necessary to determine reaction kinetics. The platform is flexible in terms of use case: it can be used either to investigate reaction kinetics or to perform reaction optimization over a wide range of chemical domains., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)
- Published
- 2023
- Full Text
- View/download PDF
15. Acute Pharmacological Inhibition of Protein Kinase R-Like Endoplasmic Reticulum Kinase Signaling After Spinal Cord Injury Spares Oligodendrocytes and Improves Locomotor Recovery.
- Author
-
Saraswat Ohri S, Andres KR, Howard RM, Brown BL, Forston MD, Hetman M, and Whittemore SR
- Subjects
- Animals, Mice, Endoplasmic Reticulum metabolism, Cell Death, Endoplasmic Reticulum Stress physiology, Protein Kinases metabolism, Oligodendroglia metabolism, Apoptosis, Spinal Cord Injuries drug therapy, Spinal Cord Injuries metabolism
- Abstract
Protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) is a major signal transducer of the endoplasmic reticulum stress response (ERSR) pathway. Outcomes of PERK activation range from abrogating ER stress to induction of cell death, dependent on its level, duration, and cellular context. Current data demonstrate that after mouse spinal cord injury (SCI), acute inhibition of PERK (0-72 h) with the small molecule inhibitor GSK2656157 reduced ERSR while improving white matter sparing and hindlimb locomotion recovery. GSK2656157-treated mice showed increased numbers of oligodendrocytes at the injury epicenter. Moreover, GSK2656157 protected cultured primary mouse oligodendrocyte precursor cells from ER stress-induced cytotoxicity. These findings suggest that in the context of SCI, excessive acute activation of PERK contributes to functionally relevant white matter damage. Pharmacological inhibition of PERK is a potential strategy to protect central nervous system (CNS) white matter following acute injuries, including SCI.
- Published
- 2023
- Full Text
- View/download PDF
16. A Reductive Aminase Switches to Imine Reductase Mode for a Bulky Amine Substrate.
- Author
-
Gilio AK, Thorpe TW, Heyam A, Petchey MR, Pogrányi B, France SP, Howard RM, Karmilowicz MJ, Lewis R, Turner N, and Grogan G
- Abstract
Imine reductases (IREDs) catalyze the asymmetric reduction of cyclic imines, but also in some cases the coupling of ketones and amines to form secondary amine products in an enzyme-catalyzed reductive amination (RedAm) reaction. Enzymatic RedAm reactions have typically used small hydrophobic amines, but many interesting pharmaceutical targets require that larger amines be used in these coupling reactions. Following the identification of IR77 from Ensifer adhaerens as a promising biocatalyst for the reductive amination of cyclohexanone with pyrrolidine, we have characterized the ability of this enzyme to catalyze couplings with larger bicyclic amines such as isoindoline and octahydrocyclopenta( c )pyrrole. By comparing the activity of IR77 with reductions using sodium cyanoborohydride in water, it was shown that, while the coupling of cyclohexanone and pyrrolidine involved at least some element of reductive amination, the amination with the larger amines likely occurred ex situ, with the imine recruited from solution for enzyme reduction. The structure of IR77 was determined, and using this as a basis, structure-guided mutagenesis, coupled with point mutations selecting improving amino acid sites suggested by other groups, permitted the identification of a mutant A208N with improved activity for amine product formation. Improvements in conversion were attributed to greater enzyme stability as revealed by X-ray crystallography and nano differential scanning fluorimetry. The mutant IR77-A208N was applied to the preparative scale amination of cyclohexanone at 50 mM concentration, with 1.2 equiv of three larger amines, in isolated yields of up to 93%., Competing Interests: The authors declare the following competing financial interest(s): Mark Petchey is currently a Postdoctoral Researcher at AstraZeneca R&D Gothenburg., (© 2023 The Authors. Published by American Chemical Society.)
- Published
- 2023
- Full Text
- View/download PDF
17. Multifunctional biocatalyst for conjugate reduction and reductive amination.
- Author
-
Thorpe TW, Marshall JR, Harawa V, Ruscoe RE, Cuetos A, Finnigan JD, Angelastro A, Heath RS, Parmeggiani F, Charnock SJ, Howard RM, Kumar R, Daniels DSB, Grogan G, and Turner NJ
- Subjects
- Amination, Biocatalysis, Imines chemistry, Stereoisomerism, Amines chemistry, Oxidoreductases genetics, Oxidoreductases metabolism
- Abstract
Chiral amine diastereomers are ubiquitous in pharmaceuticals and agrochemicals
1 , yet their preparation often relies on low-efficiency multi-step synthesis2 . These valuable compounds must be manufactured asymmetrically, as their biochemical properties can differ based on the chirality of the molecule. Herein we characterize a multifunctional biocatalyst for amine synthesis, which operates using a mechanism that is, to our knowledge, previously unreported. This enzyme (EneIRED), identified within a metagenomic imine reductase (IRED) collection3 and originating from an unclassified Pseudomonas species, possesses an unusual active site architecture that facilitates amine-activated conjugate alkene reduction followed by reductive amination. This enzyme can couple a broad selection of α,β-unsaturated carbonyls with amines for the efficient preparation of chiral amine diastereomers bearing up to three stereocentres. Mechanistic and structural studies have been carried out to delineate the order of individual steps catalysed by EneIRED, which have led to a proposal for the overall catalytic cycle. This work shows that the IRED family can serve as a platform for facilitating the discovery of further enzymatic activities for application in synthetic biology and organic synthesis., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)- Published
- 2022
- Full Text
- View/download PDF
18. More Facetime: An Emerging Role for Telemedicine in Facial Transplantation.
- Author
-
Howard RM, Trilles J, Kimberly LL, Berman ZP, Diep GK, Boczar D, Colon RR, and Rodriguez ED
- Subjects
- Humans, United States, Waiting Lists, Facial Transplantation standards, Patient Selection, Telemedicine
- Published
- 2021
- Full Text
- View/download PDF
19. Cell-free in vitro reduction of carboxylates to aldehydes: With crude enzyme preparations to a key pharmaceutical building block.
- Author
-
Schwarz A, Hecko S, Rudroff F, Kohrt JT, Howard RM, and Winkler M
- Subjects
- Carboxylic Acids, Catalysis, NADP, Aldehydes, Pharmaceutical Preparations
- Abstract
The scarcity of practical methods for aldehyde synthesis in chemistry necessitates the development of mild, selective procedures. Carboxylic acid reductases catalyze aldehyde formation from stable carboxylic acid precursors in an aqueous solution. Carboxylic acid reductases were employed to catalyze aldehyde formation in a cell-free system with activation energy and reducing equivalents provided through auxiliary proteins for ATP and NADPH recycling. In situ product removal was used to suppress over-reduction due to background enzyme activities, and an N-protected 4-formyl-piperidine pharma synthon was prepared in 61% isolated yield. This is the first report of preparative aldehyde synthesis with carboxylic acid reductases employing crude, commercially available enzyme preparations., (© 2021 The Authors. Biotechnology Journal published by Wiley-VCH GmbH.)
- Published
- 2021
- Full Text
- View/download PDF
20. Dual-Viral Transduction Utilizing Highly Efficient Retrograde Lentivirus Improves Labeling of Long Propriospinal Neurons.
- Author
-
Brown BL, Zalla RM, Shepard CT, Howard RM, Kopechek JA, Magnuson DSK, and Whittemore SR
- Abstract
The nervous system coordinates pathways and circuits to process sensory information and govern motor behaviors. Mapping these pathways is important to further understand the connectivity throughout the nervous system and is vital for developing treatments for neuronal diseases and disorders. We targeted long ascending propriospinal neurons (LAPNs) in the rat spinal cord utilizing Fluoro-Ruby (FR) [10kD rhodamine dextran amine (RDA)], and two dual-viral systems. Dual-viral tracing utilizing a retrograde adeno-associated virus (retroAAV), which confers robust labeling in the brain, resulted in a small number of LAPNs being labeled, but dual-viral tracing using a highly efficient retrograde (HiRet) lentivirus provided robust labeling similar to FR. Additionally, dual-viral tracing with HiRet lentivirus and tracing with FR may preferentially label different subpopulations of LAPNs. These data demonstrate that dual-viral tracing in the spinal cord employing a HiRet lentivirus provides robust and specific labeling of LAPNs and emphasizes the need to empirically optimize viral systems to target specific neuronal population(s)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Brown, Zalla, Shepard, Howard, Kopechek, Magnuson and Whittemore.)
- Published
- 2021
- Full Text
- View/download PDF
21. Oligodendrocyte-specific deletion of Xbp1 exacerbates the endoplasmic reticulum stress response and restricts locomotor recovery after thoracic spinal cord injury.
- Author
-
Saraswat Ohri S, Howard RM, Liu Y, Andres KR, Shepard CT, Hetman M, and Whittemore SR
- Subjects
- Animals, Mice, Mice, Inbred C57BL, Mice, Knockout, Oligodendroglia, Endoplasmic Reticulum Stress, Spinal Cord Injuries genetics
- Abstract
The endoplasmic reticulum stress response (ERSR) is activated in various neurodegenerative diseases and/or after CNS traumatic injuries. The ERSR is comprised of three major arms, PERK, IRE-1, and activating transcription factor-6, with the latter two contributing to the unfolded protein response (UPR). PERK activity overlaps with the integrated stress response (ISR) kinases, PKR, HRI, and GCN2 which all signal through, eukaryotic initiation factor 2α, ATF4, and CHOP. All initially attempt to restore endoplasmic reticulum (ER) homeostasis, but if ER stress is unresolved, ATF4/CHOP-mediated cell death is initiated. Here, we investigate the contribution of the inositol-requiring protein-1α-X-box binding protein-1 (XBP1)-mediated UPR signaling pathway to the pathogenesis of spinal cord injury (SCI). We demonstrate that deletion of Xbp1 caused an exacerbated ATF4/CHOP signaling in cultured mouse oligodendrocyte (OL) progenitor cells and enhanced their sensitivity to ER stress. Similar effects were also observed with the Xbp1 pathway inhibitor toyocamycin. Furthermore, OL lineage-specific loss of Xbp1 resulted in enhanced ISR in mice that underwent moderate contusive SCI at the T9 level. Consistently, post-injury recovery of hindlimb locomotion and white matter sparing were reduced in OL Xbp1-deficient mice, which correlated with chronically decreased relative density of OPCs and OLs at the injury epicenter at 6 weeks post-SCI. We conclude that the IRE1-XBP1-mediated UPR signaling pathway contributes to restoration of ER homeostasis in OLs and is necessary for enhanced white matter sparing and functional recovery post-SCI., (© 2020 Wiley Periodicals LLC.)
- Published
- 2021
- Full Text
- View/download PDF
22. PF-07059013: A Noncovalent Modulator of Hemoglobin for Treatment of Sickle Cell Disease.
- Author
-
Gopalsamy A, Aulabaugh AE, Barakat A, Beaumont KC, Cabral S, Canterbury DP, Casimiro-Garcia A, Chang JS, Chen MZ, Choi C, Dow RL, Fadeyi OO, Feng X, France SP, Howard RM, Janz JM, Jasti J, Jasuja R, Jones LH, King-Ahmad A, Knee KM, Kohrt JT, Limberakis C, Liras S, Martinez CA, McClure KF, Narayanan A, Narula J, Novak JJ, O'Connell TN, Parikh MD, Piotrowski DW, Plotnikova O, Robinson RP, Sahasrabudhe PV, Sharma R, Thuma BA, Vasa D, Wei L, Wenzel AZ, Withka JM, Xiao J, and Yayla HG
- Subjects
- Animals, Erythrocytes metabolism, Mice, Oxygen metabolism, Quinolines chemistry, Anemia, Sickle Cell drug therapy, Hemoglobin A drug effects, Hemoglobin, Sickle drug effects, Quinolines pharmacology, Quinolines therapeutic use
- Abstract
Sickle cell disease (SCD) is a genetic disorder caused by a single point mutation (β6 Glu → Val) on the β-chain of adult hemoglobin (HbA) that results in sickled hemoglobin (HbS). In the deoxygenated state, polymerization of HbS leads to sickling of red blood cells (RBC). Several downstream consequences of polymerization and RBC sickling include vaso-occlusion, hemolytic anemia, and stroke. We report the design of a noncovalent modulator of HbS, clinical candidate PF-07059013 ( 23 ). The seminal hit molecule was discovered by virtual screening and confirmed through a series of biochemical and biophysical studies. After a significant optimization effort, we arrived at 23 , a compound that specifically binds to Hb with nanomolar affinity and displays strong partitioning into RBCs. In a 2-week multiple dose study using Townes SCD mice, 23 showed a 37.8% (±9.0%) reduction in sickling compared to vehicle treated mice. 23 (PF-07059013) has advanced to phase 1 clinical trials.
- Published
- 2021
- Full Text
- View/download PDF
23. Treatment of calcinosis cutis with sodium thiosulfate therapy.
- Author
-
Howard RM and Smith GP
- Subjects
- Humans, Retrospective Studies, Antioxidants therapeutic use, Calcinosis drug therapy, Skin Diseases drug therapy, Thiosulfates therapeutic use
- Published
- 2020
- Full Text
- View/download PDF
24. The importance of being honest? Evidence that deception may not pollute social science subject pools after all.
- Author
-
Krasnow MM, Howard RM, and Eisenbruch AB
- Subjects
- Attitude, Humans, Research Design, Deception, Social Sciences
- Abstract
Deceiving participants about the goals or content of a study is permitted in psychological research but is largely banned in economics journals and subject pools. This ban is intended to protect a public good: If experiencing deception causes participants to be suspicious in future studies, and suspicion meaningfully influences their behavior, then the entire field suffers. We report a survey of psychologists' and economists' attitudes toward deception (N = 568) and a large, nondeceptive multisite study in which we measured participants' histories, suspicion levels, and behavior in four common economic tasks (N = 636). Economists reported more negative attitudes toward deceptive methods and greater support for the deception ban than did psychologists. The results of the behavioral study, however, do not support the "public good" argument for banning deception about the goals or content of a research study: Participants' present suspicion was not clearly related to past experiences of deception, and there were no consistent behavioral differences between suspicious and credulous participants. We discuss the implications of these results for the ongoing debate regarding the acceptability of deceptive research methods.
- Published
- 2020
- Full Text
- View/download PDF
25. Memory category fluency, memory specificity, and the fading affect bias for positive and negative autobiographical events: Performance on a good day-bad day task in healthy and depressed individuals.
- Author
-
Hitchcock C, Newby J, Timm E, Howard RM, Golden AM, Kuyken W, and Dalgleish T
- Subjects
- Adult, Female, Humans, Male, Affect, Depressive Disorder psychology, Memory, Episodic, Mental Recall
- Abstract
In mentally healthy individuals, autobiographical memory is typically biased toward positive events, which may help to maintain psychological well-being. Our aim was to assess a range of important positive memory biases in the mentally healthy and explore the possibility that these biases are mitigated in those with mental health problems. We administered a novel recall paradigm that required recollection of multiple good and bad past events (the Good Day-Bad Day task) to healthy and depressed individuals. This allowed us to explore differences in memory category fluency (i.e., the ability to generate integrated sets of associated events) for positive and negative memories, along with memory specificity, and fading affect bias-a greater reduction in the intensity of memory-related affect over time for negative versus positive events. We found that healthy participants demonstrated superior category fluency for positive relative to negative events but that this effect was absent in depressed participants. Healthy participants exhibited a strong fading affect bias that was significantly mitigated, although still present, in depression. Finally, memory specificity was reduced in depression for both positive and negative memories. Findings demonstrate that the positive bias associated with mental health is maintained by multiple autobiographical memory processes and that depression is as much a function of the absence of these positive biases as it is the presence of negative biases. Results provide important guidance for developing new treatments for improving mental health. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
- Published
- 2020
- Full Text
- View/download PDF
26. One-Pot Biocatalytic Cascade Reduction of Cyclic Enimines for the Preparation of Diastereomerically Enriched N -Heterocycles.
- Author
-
Thorpe TW, France SP, Hussain S, Marshall JR, Zawodny W, Mangas-Sanchez J, Montgomery SL, Howard RM, Daniels DSB, Kumar R, Parmeggiani F, and Turner NJ
- Subjects
- Heterocyclic Compounds chemistry, Molecular Structure, Oxidation-Reduction, Stereoisomerism, Biocatalysis, Heterocyclic Compounds chemical synthesis, Imines chemistry, Oxidoreductases chemistry
- Abstract
Ene-reductases (EREDs) catalyze the reduction of electron-deficient C═C bonds. Herein, we report the first example of ERED-catalyzed net reduction of C═C bonds of enimines (α,β-unsaturated imines). Preliminary studies suggest their hydrolyzed ring-open ω-amino enones are the likely substrates for this step. When combined with imine reductase (IRED)-mediated C═N reduction, the result is an efficient telescoped sequence for the preparation of diastereomerically enriched 2-substituted saturated amine heterocycles.
- Published
- 2019
- Full Text
- View/download PDF
27. Universality and diversity in human song.
- Author
-
Mehr SA, Singh M, Knox D, Ketter DM, Pickens-Jones D, Atwood S, Lucas C, Jacoby N, Egner AA, Hopkins EJ, Howard RM, Hartshorne JK, Jennings MV, Simson J, Bainbridge CM, Pinker S, O'Donnell TJ, Krasnow MM, and Glowacki L
- Subjects
- Auditory Perception, Behavior, Cross-Cultural Comparison, Dancing, Humans, Infant Care, Infant, Newborn, Love, Psychoacoustics, Religion, Anthropology, Cultural, Music, Singing
- Abstract
What is universal about music, and what varies? We built a corpus of ethnographic text on musical behavior from a representative sample of the world's societies, as well as a discography of audio recordings. The ethnographic corpus reveals that music (including songs with words) appears in every society observed; that music varies along three dimensions (formality, arousal, religiosity), more within societies than across them; and that music is associated with certain behavioral contexts such as infant care, healing, dance, and love. The discography-analyzed through machine summaries, amateur and expert listener ratings, and manual transcriptions-reveals that acoustic features of songs predict their primary behavioral context; that tonality is widespread, perhaps universal; that music varies in rhythmic and melodic complexity; and that elements of melodies and rhythms found worldwide follow power laws., (Copyright © 2019, American Association for the Advancement of Science.)
- Published
- 2019
- Full Text
- View/download PDF
28. The discrepancy between functional outcome and self-reported health status after surgery for degenerative cervical myelopathy.
- Author
-
Tetreault LA, Zhu MP, Howard RM, Sorefan-Mangou F, Patel AA, Schroeder GD, Massicotte EM, Bhadiwala JH, Fehlings MG, and Wilson JR
- Subjects
- Aged, Female, Follow-Up Studies, Humans, Male, Middle Aged, Multivariate Analysis, Prospective Studies, Treatment Outcome, Cervical Vertebrae surgery, Health Status, Patient Outcome Assessment, Self Report, Spinal Cord Diseases surgery
- Abstract
Introduction: Surgery for degenerative cervical myelopathy has shown not only to halt neurologic deterioration, but also to improve functional impairments. Despite these improvements, some patients may be dissatisfied with their outcomes. This study aims to (1) investigate discrepancies between postoperative clinical measures and self-reported health status, and (2) identify important predictors of such discrepancies., Methods: Four hundred and seventy-nine surgical patients were prospectively enrolled in the CSM-International study at 16 global sites. At 1-year post-op, patients rated their general health status compared with their immediate preoperative status (much better, somewhat better, the same, somewhat worse, much worse). Descriptive analyses were conducted to evaluate the agreement between achieving a clinically important improvement (MCID) in function (modified Japanese Orthopedic Association [mJOA] scale) and self-reported health status. Agreement was defined as achieving the MCID on the mJOA and reporting general health as somewhat better or much better, whereas disagreement was defined as achieving MCID on the mJOA and reporting general health as the same, somewhat worse or much worse. Logistic regression analysis was used to determine factors that influence agreement between self-report of health status and functional outcomes., Results: A total of 395 patients had complete follow-up data at 1-year and were included in this analysis. Based on patient self-reports, 56 (14.2%) were somewhat or much worse than a year ago, 80 (20.2%) patients were the same and 259 (65.6%) patients were somewhat or much better. Thirty percent of patients who reported being somewhat or much worse were found to achieve the MCID on the mJOA; 57.5% of patients who indicated their health status were the same as before surgery also exhibited clinically meaningful improvements in functional impairment. Based on multivariate analysis, there was an increased odds of observing an agreement between self-reports of health status and functional outcomes if the patient exhibited greater improvement in mJOA upper extremity motor function at 1-year (odds ratio [OR]: 1.41, 95% confidence interval [CI] 1.03-1.93, p=.033) and reduced odds of agreement with increased age (OR for every decade: 0.66, 95% CI 0.50-0.87, p=.0035) and increased bodily pain at 1-year (OR: 0.62, 95% CI 0.49-078, p<.0001)., Conclusions: There was a discrepancy between changes in mJOA and self-reports of health status in patients undergoing surgery for degenerative cervical myelopathy. Increased bodily pain at 1-year, smaller improvements in postoperative upper extremity score and increased age were associated with worsened or unchanged general health status, despite clinically significant improvements in overall postoperative function., (Copyright © 2019 Elsevier Inc. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
29. Sexual violence victimization among community college students.
- Author
-
Howard RM, Potter SJ, Guedj CE, and Moynihan MM
- Subjects
- Adolescent, Adult, Female, Humans, Male, New England epidemiology, Prevalence, Sex Factors, Surveys and Questionnaires, Young Adult, Bullying statistics & numerical data, Crime Victims statistics & numerical data, Sex Offenses statistics & numerical data, Sexual Behavior statistics & numerical data, Students statistics & numerical data, Universities statistics & numerical data
- Abstract
Objective : To assess the prevalence of sexual violence victimization among a community college student population. Participants : In March 2017, students (800) from seven community colleges in a northeastern state participated in an online campus climate survey using the ARC3 Survey Instrument. Methods: We analyze demographic differences between participants who were victimized and those who were not, and we examine the relationship between participant victimization and well-being. Results: Participants who identified as female, younger than 26, not heterosexual, or a race other than Caucasian were significantly more likely to report victimization. Participants who reported victimization were significantly more likely to score negatively on well-being scales than those who did not. Conclusions : Sexual violence prevalence rates among community college students are similar to reported prevalence rates among traditional 4-year undergraduate students. Results suggest a need for increased research on sexual violence among the understudied community college student population.
- Published
- 2019
- Full Text
- View/download PDF
30. Characterizing the pharmacogenome using molecular inversion probes for targeted next-generation sequencing.
- Author
-
Suzuki O, Dong OM, Howard RM, and Wiltshire T
- Subjects
- Genetic Testing, Humans, Precision Medicine, Sequence Analysis, DNA methods, Genome, Human genetics, High-Throughput Nucleotide Sequencing, Pharmacogenetics, Pharmacogenomic Testing methods
- Abstract
Aim: This study assesses the technical performance and cost of a targeted next-generation sequencing (NGS) multigene pharmacogenetic (PGx) test. Materials & methods: A genetic test was developed for 21 PGx genes using molecular inversion probes to generate library fragments for NGS. Performance of this test was assessed using 53 unique reference control cell lines from the Genetic Testing Reference Materials Coordination Program (GeT-RM). Results: 93.7% of variants were successfully called and the repeatability rate was 99.9%. Reference calls were available for 78.4% of diplotype calls resulting from PGx testing, and concordance for the test was 85.7%. Cost per sample was $32-$56. Conclusion: A targeted NGS assay using molecular inversion probe technology is able to characterize the pharmacogenome efficiently.
- Published
- 2019
- Full Text
- View/download PDF
31. Autophagy is essential for oligodendrocyte differentiation, survival, and proper myelination.
- Author
-
Bankston AN, Forston MD, Howard RM, Andres KR, Smith AE, Ohri SS, Bates ML, Bunge MB, and Whittemore SR
- Subjects
- Animals, Autophagy-Related Protein 5 deficiency, Autophagy-Related Protein 5 genetics, Cells, Cultured, Cerebral Cortex physiology, Coculture Techniques, Female, Ganglia, Spinal physiology, Male, Mice, Inbred C57BL, Mice, Transgenic, Rats, Sprague-Dawley, Autophagy physiology, Cell Survival physiology, Neurogenesis physiology, Oligodendrocyte Precursor Cells physiology, Oligodendroglia physiology
- Abstract
Deficient myelination, the spiral wrapping of highly specialized membrane around axons, causes severe neurological disorders. Maturation of oligodendrocyte progenitor cells (OPC) to myelinating oligodendrocytes (OL), the sole providers of central nervous system (CNS) myelin, is tightly regulated and involves extensive morphological changes. Here, we present evidence that autophagy, the targeted isolation of cytoplasm and organelles by the double-membrane autophagosome for lysosomal degradation, is essential for OPC/OL differentiation, survival, and proper myelin development. A marked increase in autophagic activity coincides with OL differentiation, with OL processes having the greatest increase in autophagic flux. Multiple lines of evidence indicate that autophagosomes form in developing myelin sheathes before trafficking from myelin to the OL soma. Mice with conditional OPC/OL-specific deletion of the essential autophagy gene Atg5 beginning on postnatal Day 5 develop a rapid tremor and die around postnatal Day 12. Further analysis revealed apoptotic death of OPCs, reduced differentiation, and reduced myelination. Surviving Atg5
-/- OLs failed to produce proper myelin structure. In vitro, pharmacological inhibition of autophagy in OPC/dorsal root ganglion (DRG) co-cultures blocked myelination, producing OLs surrounded by many short processes. Conversely, autophagy stimulation enhanced myelination. These results implicate autophagy as a key regulator of OPC survival, maturation, and proper myelination. Autophagy may provide an attractive target to promote both OL survival and subsequent myelin repair after injury., (© 2019 Wiley Periodicals, Inc.)- Published
- 2019
- Full Text
- View/download PDF
32. Challenges and Solutions for Future Pharmacy Practice in the Era of Precision Medicine.
- Author
-
Dong OM, Howard RM, Church R, Cottrell M, Forrest A, Innocenti F, Mosedale M, Kashuba A, Gonzalez D, and Wiltshire T
- Subjects
- Congresses as Topic, Delivery of Health Care methods, Humans, Pharmacists, Education, Pharmacy methods, Education, Pharmacy trends, Pharmacy methods, Pharmacy trends, Precision Medicine methods, Precision Medicine trends
- Abstract
As precision medicine research and its clinical applications continue to advance, it is critical for pharmacists to be involved in these developments to deliver optimal, tailored drug therapies for patients. To ensure pharmacists remain leaders in the field, the annual Pharmaceutical Sciences Conference convened by the University of North Carolina at Chapel Hill Eshelman School of Pharmacy focused on the role of pharmacy within precision medicine. This is a summary of the conference, highlighting the major challenges and solutions that will help advance individualized pharmacological methods within practice and research.
- Published
- 2018
- Full Text
- View/download PDF
33. Blocking Autophagy in Oligodendrocytes Limits Functional Recovery after Spinal Cord Injury.
- Author
-
Saraswat Ohri S, Bankston AN, Mullins SA, Liu Y, Andres KR, Beare JE, Howard RM, Burke DA, Riegler AS, Smith AE, Hetman M, and Whittemore SR
- Subjects
- Animals, Autophagy-Related Protein 5 deficiency, Female, Mice, Mice, Inbred C57BL, Mice, Knockout, Spinal Cord Injuries physiopathology, Autophagy physiology, Nerve Regeneration physiology, Oligodendroglia pathology, Recovery of Function physiology, Spinal Cord Injuries pathology
- Abstract
Autophagy mechanisms are well documented in neurons after spinal cord injury (SCI), but the direct functional role of autophagy in oligodendrocyte (OL) survival in SCI pathogenesis remains unknown. Autophagy is an evolutionary conserved lysosomal-mediated catabolic pathway that ensures degradation of dysfunctional cellular components to maintain homeostasis in response to various forms of stress, including nutrient deprivation, hypoxia, reactive oxygen species, DNA damage, and endoplasmic reticulum (ER) stress. Using pharmacological gain and loss of function and genetic approaches, we investigated the contribution of autophagy in OL survival and its role in the pathogenesis of thoracic contusive SCI in female mice. Although upregulation of Atg5 (an essential autophagy gene) occurs after SCI, autophagy flux is impaired. Purified myelin fractions of contused 8 d post-SCI samples show enriched protein levels of LC3B, ATG5, and BECLIN 1. Data show that, while the nonspecific drugs rapamycin (activates autophagy) and spautin 1 (blocks autophagy) were pharmacologically active on autophagy in vivo , their administration did not alter locomotor recovery after SCI. To directly analyze the role of autophagy, transgenic mice with conditional deletion of Atg5 in OLs were generated. Analysis of hindlimb locomotion demonstrated a significant reduction in locomotor recovery after SCI that correlated with a greater loss in spared white matter. Immunohistochemical analysis demonstrated that deletion of Atg5 from OLs resulted in decreased autophagic flux and was detrimental to OL function after SCI. Thus, our study provides evidence that autophagy is an essential cytoprotective pathway operating in OLs and is required for hindlimb locomotor recovery after thoracic SCI. SIGNIFICANCE STATEMENT This study describes the role of autophagy in oligodendrocyte (OL) survival and pathogenesis after thoracic spinal cord injury (SCI). Modulation of autophagy with available nonselective drugs after thoracic SCI does not affect locomotor recovery despite being pharmacologically active in vivo , indicating significant off-target effects. Using transgenic mice with conditional deletion of Atg5 in OLs, this study definitively identifies autophagy as an essential homeostatic pathway that operates in OLs and exhibits a direct functional role in SCI pathogenesis and recovery. Therefore, this study emphasizes the need to discover novel autophagy-specific drugs that specifically modulate autophagy for further investigation for clinical translation to treat SCI and other CNS pathologies related to OL survival., (Copyright © 2018 the authors 0270-6474/18/385900-13$15.00/0.)
- Published
- 2018
- Full Text
- View/download PDF
34. Muscle activity in sprinting: a review.
- Author
-
Howard RM, Conway R, and Harrison AJ
- Subjects
- Biomechanical Phenomena, Gait physiology, Humans, Lower Extremity physiology, Electromyography, Muscle, Skeletal physiology, Running physiology
- Abstract
The use of electromyography (EMG) is widely recognised as a valuable tool for enhancing the understanding of performance drivers and potential injury risk in sprinting. The timings of muscle activations relative to running gait cycle phases and the technology used to obtain muscle activation data during sprinting are of particular interest to scientists and coaches. This review examined the main muscles being analysed by surface EMG (sEMG), their activations and timing, and the technologies used to gather sEMG during sprinting. Electronic databases were searched using 'Electromyography' OR 'EMG' AND 'running' OR 'sprinting'. Based on inclusion criteria, 18 articles were selected for review. While sEMG is widely used in biomechanics, relatively few studies have used sEMG in sprinting due to system constraints. The results demonstrated a focus on the leg muscles, with over 70% of the muscles analysed in the upper leg. This is consistent with the use of tethered and data logging EMG systems and many sprints being performed on treadmills. Through the recent advances in wireless EMG technology, an increase in the studies on high velocity movements such as sprinting is expected and this should allow practitioners to perform the analysis in an ecologically valid environment.
- Published
- 2018
- Full Text
- View/download PDF
35. Affective enhancement of working memory is maintained in depression.
- Author
-
Schweizer S, Navrady L, Breakwell L, Howard RM, Golden AM, Werner-Seidler A, and Dalgleish T
- Subjects
- Adolescent, Adult, Female, Humans, Male, Middle Aged, Young Adult, Affect physiology, Depression physiopathology, Depressive Disorder, Major physiopathology, Memory, Short-Term physiology
- Abstract
We currently know little about how performance on assessments of working memory capacity (WMC) that are designed to mirror the concurrent task demands of daily life are impacted by the presence of affective information, nor how those effects may be modulated by depression-a syndrome where sufferers report global difficulties with executive processing. Across 3 experiments, we investigated WMC for sets of neutral words in the context of processing either neutral or affective (depressogenic) sentences, which had to be judged on semantic accuracy (Experiments 1 and 2) or self-reference (Experiment 3). Overall, WMC was significantly better in the context of depressogenic compared with neutral sentences. However, there was no support for this effect being modulated by symptoms of depression (Experiment 1) or the presence of recurrent major depressive disorder (MDD; Experiments 2 and 3). Implications of these findings for cognitive theories of the role of WM in depression are discussed in the context of a growing body of research showing no support for a differential impact of depressogenic compared with neutral information on WM accuracy. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)
- Published
- 2018
- Full Text
- View/download PDF
36. Biocatalytic Routes to Enantiomerically Enriched Dibenz[c,e]azepines.
- Author
-
France SP, Aleku GA, Sharma M, Mangas-Sanchez J, Howard RM, Steflik J, Kumar R, Adams RW, Slabu I, Crook R, Grogan G, Wallace TW, and Turner NJ
- Subjects
- Azepines chemistry, Biocatalysis, Molecular Structure, Stereoisomerism, Azepines metabolism, Oxidoreductases Acting on CH-NH Group Donors metabolism, Transaminases metabolism
- Abstract
Biocatalytic retrosynthetic analysis of dibenz[c,e]azepines has highlighted the use of imine reductase (IRED) and ω-transaminase (ω-TA) biocatalysts to establish the key stereocentres of these molecules. Several enantiocomplementary IREDs were identified for the synthesis of (R)- and (S)-5-methyl-6,7-dihydro-5H-dibenz[c,e]azepine with excellent enantioselectivity, by reduction of the parent imines. Crystallographic evidence suggests that IREDs may be able to bind one conformer of the imine substrate such that, upon reduction, the major product conformer is generated directly. ω-TA biocatalysts were also successfully employed for the production of enantiopure 1-(2-bromophenyl)ethan-1-amine, thus enabling an orthogonal route for the installation of chirality into dibenz[c,e]azepine framework., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2017
- Full Text
- View/download PDF
37. Muscle activation sequencing of leg muscles during linear glide shot putting.
- Author
-
Howard RM, Conway R, and Harrison AJ
- Subjects
- Biomechanical Phenomena, Electromyography, Female, Humans, Male, Movement, Time Factors, Young Adult, Leg physiology, Motor Skills physiology, Muscle, Skeletal physiology, Track and Field physiology
- Abstract
In the shot put, the athlete's muscles are responsible for generating the impulses to move the athlete and project the shot into the air. Information on phasic muscle activity is lacking for the glide shot put event and therefore important technical information for coaches is not currently available. This study provides an electromyography (EMG) analysis of the muscle activity of the legs during shot put. Fifteen right-handed Irish national level shot putters performed six maximum effort throws using the glide shot put technique. EMG records of eight bilateral lower limb muscles (rectus femoris, biceps femoris, medial- and lateral-gastrocnemius) were obtained during trials. Analysis using smooth EMG linear envelopes revealed patterns of muscle activity across the phases of the throw and compare men and women performers. The results showed that the preferred leg rectus femoris, the preferred leg biceps femoris and the non-preferred leg biceps femoris play important roles in the glide technique, with the total duration of high volumes of activity between 34 and 53% of the throw cycle. A comprehensive understanding of movement and muscle activation patterns for coaches could be helpful to facilitate optimal technique throughout each of the key phases of the event.
- Published
- 2017
- Full Text
- View/download PDF
38. Genomic Imprinting Is Implicated in the Psychology of Music.
- Author
-
Mehr SA, Kotler J, Howard RM, Haig D, and Krasnow MM
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Female, Humans, Male, Middle Aged, Prader-Willi Syndrome genetics, Young Adult, Genomic Imprinting physiology, Heart Rate physiology, Movement physiology, Music psychology, Pitch Perception physiology, Prader-Willi Syndrome physiopathology
- Abstract
Why do people sing to babies? Human infants are relatively altricial and need their parents' attention to survive. Infant-directed song may constitute a signal of that attention. In Prader-Willi syndrome (PWS), a rare disorder of genomic imprinting, genes from chromosome 15q11-q13 that are typically paternally expressed are unexpressed, which results in exaggeration of traits that reduce offspring's investment demands on the mother. PWS may thus be associated with a distinctive musical phenotype. We report unusual responses to music in people with PWS. Subjects with PWS ( N = 39) moved more during music listening, exhibited greater reductions in heart rate in response to music listening, and displayed a specific deficit in pitch-discrimination ability relative to typically developing adults and children ( N = 589). Paternally expressed genes from 15q11-q13, which are unexpressed in PWS, may thus increase demands for music and enhance perceptual sensitivity to music. These results implicate genomic imprinting in the psychology of music, informing theories of music's evolutionary history.
- Published
- 2017
- Full Text
- View/download PDF
39. A survey of sensor devices: use in sports biomechanics.
- Author
-
Howard RM, Conway R, and Harrison AJ
- Subjects
- Accelerometry instrumentation, Adult, Biomechanical Phenomena, Biosensing Techniques instrumentation, Equipment Design, Female, Humans, Male, Software, Electromyography instrumentation, Sports physiology
- Abstract
This paper examines the use of sensor devices in sports biomechanics, focusing on current frequency of use of Electromyography (EMG) device preferences. Researchers in the International Society of Biomechanics in Sports were invited to participate in an online survey. Responses on multiple sensor devices highlighting frequency of use, device features and improvements researchers sought in acquisition and analysis methods were obtained via an online questionnaire. Results of the investigation showed that the force platform is the most frequently used device, with inertial measurement units and EMG devices growing in popularity. Wireless functionality and ease of use for both the participant and the practitioner proved to be important features. The main findings of the survey demonstrated need for a simple, low power, multi-channel device which incorporates the various sensors into one single device. Biomechanists showed they were looking for more availability of wireless sensor devices with acquisition and analysis features. The study found there is a need to develop software analysis tools to accompany the multi-channel device, providing all the basic functions while maintaining compatibility with existing systems.
- Published
- 2016
- Full Text
- View/download PDF
40. Remyelinating Oligodendrocyte Precursor Cell miRNAs from the Sfmbt2 Cluster Promote Cell Cycle Arrest and Differentiation.
- Author
-
Kuypers NJ, Bankston AN, Howard RM, Beare JE, and Whittemore SR
- Subjects
- Animals, Cells, Cultured, Female, Humans, Male, Mice, Mice, Transgenic, Rats, Rats, Inbred F344, Repressor Proteins, Cell Cycle Checkpoints physiology, Cell Differentiation physiology, MicroRNAs physiology, Myelin Sheath physiology, Oligodendroglia physiology, Stem Cells physiology, Transcription Factors physiology
- Abstract
Oligodendrocyte (OL) loss contributes to the functional deficits underlying diseases with a demyelinating component. Remyelination by oligodendrocyte progenitor cells (OPCs) can restore these deficits. To understand the role that microRNAs (miRNAs) play in remyelination, 2',3'-cyclic-nucleotide 3'-phosphodiesterase-EGFP(+) mice were treated with cuprizone, and OPCs were sorted from the corpus callosum. Microarray analysis revealed that Sfmbt2 family miRNAs decreased during cuprizone treatment. One particular Sfmbt2 miRNA, miR-297c-5p, increased during mouse OPC differentiation in vitro and during callosal development in vivo. When overexpressed in both mouse embryonic fibroblasts and rat OPCs (rOPCs), cell cycle analysis revealed that miR-297c-5p promoted G1/G0 arrest. Additionally, miR-297c-5p transduction increased the number of O1(+) rOPCs during differentiation. Luciferase reporter assays confirmed that miR-297c-5p targets cyclin T2 (CCNT2), the regulatory subunit of positive transcription elongation factor b, a complex that inhibits OL maturation. Furthermore, CCNT2-specific knockdown promoted rOPC differentiation while not affecting cell cycle status. Together, these data support a dual role for miR-297c-5p as both a negative regulator of OPC proliferation and a positive regulator of OL maturation via its interaction with CCNT2., Significance Statement: This work describes the role of oligodendrocyte progenitor cell (OPC) microRNAs (miRNAs) during remyelination and development in vivo and differentiation in vitro. This work highlights the importance of miRNAs to OPC biology and describes miR-297c-5p, a novel regulator of OPC function. In addition, we identified CCNT2 as a functional target, thus providing a mechanism by which miR-297c-5p imparts its effects on differentiation. These data are important, given our lack of understanding of OPC miRNA regulatory networks and their potential clinical value. Therefore, efforts to understand the role of miR-297c-5p in pathological conditions and its potential for facilitating repair may provide future therapeutic strategies to treat demyelination., (Copyright © 2016 the authors 0270-6474/16/361698-13$15.00/0.)
- Published
- 2016
- Full Text
- View/download PDF
41. Preclinical models for in vitro mechanical loading of bone-derived cells.
- Author
-
Michael Delaine-Smith R, Javaheri B, Helen Edwards J, Vazquez M, and Rumney RM
- Abstract
It is well established that bone responds to mechanical stimuli whereby physical forces are translated into chemical signals between cells, via mechanotransduction. It is difficult however to study the precise cellular and molecular responses using in vivo systems. In vitro loading models, which aim to replicate forces found within the bone microenvironment, make the underlying processes of mechanotransduction accessible to the researcher. Direct measurements in vivo and predictive modeling have been used to define these forces in normal physiological and pathological states. The types of mechanical stimuli present in the bone include vibration, fluid shear, substrate deformation and compressive loading, which can all be applied in vitro to monolayer and three-dimensional (3D) cultures. In monolayer, vibration can be readily applied to cultures via a low-magnitude, high-frequency loading rig. Fluid shear can be applied to cultures in multiwell plates via a simple rocking platform to engender gravitational fluid movement or via a pump to cells attached to a slide within a parallel-plate flow chamber, which may be micropatterned for use with osteocytes. Substrate strain can be applied via the vacuum-driven FlexCell system or via a four-point loading jig. 3D cultures better replicate the bone microenvironment and can also be subjected to the same forms of mechanical stimuli as monolayer, including vibration, fluid shear via perfusion flow, strain or compression. 3D cocultures that more closely replicate the bone microenvironment can be used to study the collective response of several cell types to loading. This technical review summarizes the methods for applying mechanical stimuli to bone cells in vitro.
- Published
- 2015
- Full Text
- View/download PDF
42. Relationship between brain glutamate levels and clinical outcome in individuals at ultra high risk of psychosis.
- Author
-
Egerton A, Stone JM, Chaddock CA, Barker GJ, Bonoldi I, Howard RM, Merritt K, Allen P, Howes OD, Murray RM, McLean MA, Lythgoe DJ, O'Gorman RL, and McGuire PK
- Subjects
- Adult, Female, Follow-Up Studies, Humans, Longitudinal Studies, Male, Proton Magnetic Resonance Spectroscopy, Psychiatric Status Rating Scales, Psychotic Disorders diagnosis, Risk, Young Adult, Brain metabolism, Glutamic Acid metabolism, Psychotic Disorders metabolism
- Abstract
Alterations in brain glutamate levels may be associated with psychosis risk, but the relationship to clinical outcome in at-risk individuals is unknown. Glutamate concentration was measured in the left thalamus and anterior cingulate cortex (ACC) using 3-Tesla proton magnetic resonance spectroscopy in 75 participants at ultra high risk (UHR) of psychosis and 56 healthy controls. The severity of attenuated positive symptoms and overall functioning were assessed. Measures were repeated in 51 UHR and 33 Control subjects after a mean of 18 months. UHR subjects were allocated to either remission (no longer meeting UHR criteria) or non-remission (meeting UHR or psychosis criteria) status on follow-up assessment. Thalamic glutamate levels at presentation were lower in the UHR non-remission (N=29) compared with the remission group (N=22) (t(49)=3.03; P=0.004), and were associated with an increase in the severity of total positive symptoms over time (r=-0.33; df=47; P=0.02), most notably abnormal thought content (r=-0.442; df=47; P=0.003). In the UHR group, ACC glutamate levels were lower at follow-up compared with baseline (F(80)=4.28; P=0.04). These findings suggest that measures of brain glutamate function may be useful as predictors of clinical outcome in individuals at high risk of psychosis.
- Published
- 2014
- Full Text
- View/download PDF
43. Analytical performance issues. Two different methods, three different variations, four different sources: what bulk asbestos PLM method is your laboratory using? Part 2.
- Author
-
McGrath DB, Van Orden DR, Howard RM, Guerrero P, and Davis SC
- Subjects
- Humans, United States, Asbestos analysis, Microscopy, Polarization methods, Occupational Exposure analysis, Occupational Exposure legislation & jurisprudence, United States Environmental Protection Agency legislation & jurisprudence
- Published
- 2010
- Full Text
- View/download PDF
44. Two different methods, three different variations, four different sources: what bulk asbestos PLM method is your laboratory using? Part 1.
- Author
-
McGrath DB, Van Orden DR, Howard RM, Guerrero P, and Davis SC
- Subjects
- Humans, Microscopy, Polarization methods, Microscopy, Polarization standards, United States, Asbestos analysis, Materials Testing standards, United States Environmental Protection Agency legislation & jurisprudence
- Published
- 2010
- Full Text
- View/download PDF
45. Transplantation of ciliary neurotrophic factor-expressing adult oligodendrocyte precursor cells promotes remyelination and functional recovery after spinal cord injury.
- Author
-
Cao Q, He Q, Wang Y, Cheng X, Howard RM, Zhang Y, DeVries WH, Shields CB, Magnuson DS, Xu XM, Kim DH, and Whittemore SR
- Subjects
- Adenomatous Polyposis Coli Protein metabolism, Animals, Cell Differentiation physiology, Cells, Cultured, Ciliary Neurotrophic Factor genetics, Demyelinating Diseases metabolism, Demyelinating Diseases physiopathology, Demyelinating Diseases surgery, Disease Models, Animal, Evoked Potentials, Motor physiology, Female, Genetic Vectors genetics, Graft Survival physiology, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, Myelin Sheath metabolism, Myelin Sheath ultrastructure, Nerve Regeneration physiology, Neural Conduction physiology, Paralysis etiology, Paralysis physiopathology, Paralysis surgery, Rats, Rats, Inbred F344, Recovery of Function physiology, Spinal Cord pathology, Spinal Cord physiopathology, Spinal Cord Injuries pathology, Spinal Cord Injuries physiopathology, Transfection, Treatment Outcome, Ciliary Neurotrophic Factor metabolism, Oligodendroglia metabolism, Spinal Cord surgery, Spinal Cord Injuries surgery, Stem Cell Transplantation methods, Stem Cells metabolism
- Abstract
Demyelination contributes to the dysfunction after traumatic spinal cord injury (SCI). We explored whether the combination of neurotrophic factors and transplantation of adult rat spinal cord oligodendrocyte precursor cells (OPCs) could enhance remyelination and functional recovery after SCI. Ciliary neurotrophic factor (CNTF) was the most effective neurotrophic factor to promote oligodendrocyte (OL) differentiation and survival of OPCs in vitro. OPCs were infected with retroviruses expressing enhanced green fluorescent protein (EGFP) or CNTF and transplanted into the contused adult thoracic spinal cord 9 d after injury. Seven weeks after transplantation, the grafted OPCs survived and integrated into the injured spinal cord. The survival of grafted CNTF-OPCs increased fourfold compared with EGFP-OPCs. The grafted OPCs differentiated into adenomatus polyposis coli (APC(+)) OLs, and CNTF significantly increased the percentage of APC(+) OLs from grafted OPCs. Immunofluorescent and immunoelectron microscopic analyses showed that the grafted OPCs formed central myelin sheaths around the axons in the injured spinal cord. The number of OL-remyelinated axons in ventrolateral funiculus (VLF) or lateral funiculus (LF) at the injured epicenter was significantly increased in animals that received CNTF-OPC grafts compared with all other groups. Importantly, 75% of rats receiving CNTF-OPC grafts recovered transcranial magnetic motor-evoked potential and magnetic interenlargement reflex responses, indicating that conduction through the demyelinated axons in VLF or LF, respectively, was partially restored. More importantly, recovery of hindlimb locomotor function was significantly enhanced in animals receiving grafts of CNTF-OPCs. Thus, combined treatment with OPC grafts expressing CNTF can enhance remyelination and facilitate functional recovery after traumatic SCI.
- Published
- 2010
- Full Text
- View/download PDF
46. Pseudo-outbreak of Legionella pneumophila serogroup 8 infection associated with a contaminated ice machine in a bronchoscopy suite.
- Author
-
Schuetz AN, Hughes RL, Howard RM, Williams TC, Nolte FS, Jackson D, and Ribner BS
- Subjects
- Adult, Aged, Bronchoalveolar Lavage Fluid microbiology, Bronchoscopes, Cross Infection epidemiology, Cross Infection microbiology, Cross Infection transmission, Disease Reservoirs, Female, Humans, Legionella pneumophila classification, Legionella pneumophila genetics, Legionnaires' Disease microbiology, Legionnaires' Disease transmission, Male, Middle Aged, Serotyping, Water Microbiology, Disease Outbreaks, Equipment Contamination, Ice, Legionella pneumophila isolation & purification, Legionnaires' Disease epidemiology
- Abstract
Objective: To investigate the marked increase noted over an 8-month period in the number of Legionella pneumophila isolates recovered from bronchoalveolar lavage fluid specimens obtained during bronchoscopy in our healthcare system., Setting: Bronchoscopy suite that serves a 580-bed tertiary care center and a large, multisite, faculty practice plan with approximately 2 million outpatient visits per year., Methods: Cultures of environmental specimens from the bronchoscopy suite were performed, including samples from the air and water filters, bronchoscopes, and the ice machine, with the aim of identifying Legionella species. Specimens were filtered and acid-treated and then inoculated on buffered charcoal yeast extract agar. Serogrouping was performed on all isolates recovered from patient and environmental samples., Results: All L. pneumophila isolates recovered from patients were serogroup 8, a serogroup that is not usually recovered in our facility. An epidemiologic investigation of the bronchoscopy suite revealed the ice machine to be contaminated with L. pneumophila serogroup 8. Patients were exposed to the organism as a result of a recently adopted practice in the bronchoscopy suite that involved directly immersing uncapped syringes of sterile saline in contaminated ice baths during the procedures. At least 1 patient was ill as a result of the pseudo-outbreak. Molecular typing of isolates recovered from patient and environmental samples revealed that the isolates were indistinguishable., Conclusions: Extensive cleaning of the ice machine and replacement of the machine's water filter ended the pseudo-outbreak. This episode emphasizes the importance of using aseptic technique when performing invasive procedures, such as bronchoscopies. It also demonstrates the importance of reviewing procedures in all patient areas to ensure compliance with facility policies for providing a safe patient environment.
- Published
- 2009
- Full Text
- View/download PDF
47. Oligodendrocyte precursor cells differentially expressing Nogo-A but not MAG are more permissive to neurite outgrowth than mature oligodendrocytes.
- Author
-
Ma Z, Cao Q, Zhang L, Hu J, Howard RM, Lu P, Whittemore SR, and Xu XM
- Subjects
- Analysis of Variance, Animals, Cell Differentiation drug effects, Cell Proliferation drug effects, Cells, Cultured, Embryo, Mammalian, Fibroblast Growth Factor 2 pharmacology, Ganglia, Spinal cytology, Gangliosides metabolism, Myelin Basic Protein metabolism, Neurons cytology, Neurons physiology, Nogo Proteins, Platelet-Derived Growth Factor pharmacology, Rats, Rats, Sprague-Dawley, Receptor, Platelet-Derived Growth Factor alpha metabolism, Spinal Cord cytology, Time Factors, Cell Differentiation physiology, Myelin Proteins metabolism, Neurites physiology, Oligodendroglia cytology, Oligodendroglia metabolism, Stem Cells metabolism
- Abstract
Grafting oligodendrocyte precursor cells (OPCs) has been used as a strategy to repair demyelination of the central nervous system (CNS). Whether OPCs can promote CNS axonal regeneration remains to be tested. If so, they should be permissive to axonal growth and may express less inhibitory molecules on their surface. Here we examined the expression of two oligodendrocyte-associated myelin inhibitors Nogo-A and myelin-associated glycoprotein (MAG) during oligodendrogliogenesis and tested their abilities to promote neurite outgrowth in vitro. Whereas the intracellular domain of Nogo-A was consistently expressed throughout oligodendrocyte differentiation, MAG was expressed only at later stages. Furthermore, the membrane-associated extracellular domain of Nogo-A was not expressed in OPCs but expressed in mature oligodendrocytes. In a dorsal root ganglion (DRG) and OPC/oligodendrocyte co-culture model, significantly greater DRG neurite outgrowth onto OPC monolayer than mature oligodendrocyte was found (1042+/-123 vs. 717+/-342 micrometer; p=0.011). Moreover, DRG neurites elongated as fasciculated fiber tracts and contacted directly on OPCs (133+/-37 cells/fascicle). In contrast, few, if any, direct contacts were found between DRG neurites and mature oligodendrocytes (5+/-3 cells/fascicle, p<0.001). In fact, acellular spaces were found between neurites and surrounding mature oligodendrocytes in contrast to the lack of such spaces in OPC/DRG coculture (51.1+/-16.5 vs. 2.4+/-3.9 micrometer; p<0.001). Thus, OPCs expressing neither extracellular domain of Nogo-A nor MAG are significantly more permissive than mature oligodendrocytes expressing both. Grafting OPCs may thus represent a feasible strategy to foster CNS axonal regeneration.
- Published
- 2009
- Full Text
- View/download PDF
48. Gene delivery to the spinal cord: comparison between lentiviral, adenoviral, and retroviral vector delivery systems.
- Author
-
Abdellatif AA, Pelt JL, Benton RL, Howard RM, Tsoulfas P, Ping P, Xu XM, and Whittemore SR
- Subjects
- Adenoviridae genetics, Animals, Cells, Cultured, Female, Gene Expression genetics, Genetic Vectors therapeutic use, Graft Survival genetics, Humans, Lentivirus genetics, Mice, Myelitis metabolism, Myelitis prevention & control, Myelitis virology, NIH 3T3 Cells, Nerve Growth Factors genetics, Nerve Growth Factors metabolism, Rats, Rats, Sprague-Dawley, Retroviridae genetics, Spinal Cord surgery, Spinal Cord virology, Tissue Transplantation methods, Transgenes genetics, Genetic Therapy methods, Genetic Vectors genetics, Nerve Regeneration genetics, Spinal Cord metabolism, Spinal Cord Injuries therapy, Transfection methods
- Abstract
Viral gene delivery for spinal cord injury (SCI) is a promising approach for enhancing axonal regeneration and neuroprotection. An understanding of spatio-temporal transgene expression in the spinal cord is essential for future studies of SCI therapies. Commonly, intracellular marker proteins (e.g., EGFP) were used as indicators of transgene levels after viral delivery, which may not accurately reflect levels of secreted transgene. This study examined transgene expression using ELISA after viral delivery of D15A, a neurotrophin with BDNF and NT-3 activities, at 1, 2, and 4weeks after in vivo and ex vivo delivery using lentiviral, adenoviral, and retroviral vectors. Further, the inflammatory responses and viral infection patterns after in vivo delivery were examined. Lentiviral vectors had the most stable pattern of gene expression, with D15A levels of 536 +/- 38 and 363 +/- 47 pg/mg protein seen at 4 weeks after the in vivo and ex vivo delivery, respectively. Our results show that protein levels downregulate disproportionately to levels of EGFP after adenoviral vectors both in vivo and ex vivo. D15A dropped from initial levels of 422 +/- 87 to 153 +/- 18 pg/mg protein at 4 weeks after in vivo administration. Similarly, ex vivo retrovirus-mediated transgene expression exhibited rapid downregulation by 2 weeks post-grafting. Compared to adenoviral infection, macrophage activation was attenuated after lentiviral infection. These results suggest that lentiviral vectors are most suitable in situations where stable long-term transgene expression is needed. Retroviral ex vivo delivery is optional when transient expression within targeted spinal tissue is desired, with adenoviral vectors in between.
- Published
- 2006
- Full Text
- View/download PDF
49. Consequences of noggin expression by neural stem, glial, and neuronal precursor cells engrafted into the injured spinal cord.
- Author
-
Enzmann GU, Benton RL, Woock JP, Howard RM, Tsoulfas P, and Whittemore SR
- Subjects
- Animals, Antigens metabolism, Blotting, Northern methods, Bone Morphogenetic Protein 2, Bone Morphogenetic Proteins genetics, Bone Morphogenetic Proteins metabolism, Carrier Proteins genetics, Cell Count methods, Cell Differentiation physiology, Cells, Cultured, Ectodysplasins, Electrophoretic Mobility Shift Assay methods, Embryo, Mammalian, Female, Glial Fibrillary Acidic Protein metabolism, Green Fluorescent Proteins metabolism, Immunohistochemistry methods, Intermediate Filament Proteins metabolism, Membrane Proteins metabolism, Microtubule-Associated Proteins metabolism, Nerve Tissue Proteins metabolism, Nestin, O Antigens metabolism, Oligopeptides metabolism, Phosphopyruvate Hydratase metabolism, Proteoglycans metabolism, RNA, Messenger metabolism, Rats, Rats, Inbred F344, Reverse Transcriptase Polymerase Chain Reaction methods, Spinal Cord Injuries surgery, Stem Cell Transplantation methods, Time Factors, Transfection methods, Transforming Growth Factor beta genetics, Transforming Growth Factor beta metabolism, Vimentin metabolism, Carrier Proteins metabolism, Gene Expression Regulation physiology, Neuroglia metabolism, Neurons metabolism, Spinal Cord Injuries metabolism, Stem Cells metabolism
- Abstract
Bone morphogenetic proteins (BMPs) are a large class of secreted factors, which serve as modulators of development in multiple organ systems, including the CNS. Studies investigating the potential of stem cell transplantation for restoration of function and cellular replacement following traumatic spinal cord injury (SCI) have demonstrated that the injured adult spinal cord is not conducive to neurogenesis or oligodendrogenesis of engrafted CNS precursors. In light of recent findings that BMP expression is modulated by SCI, we hypothesized that they may play a role in lineage restriction of multipotent grafts. To test this hypothesis, neural stem or precursor cells were engineered to express noggin, an endogenous antagonist of BMP action, prior to transplantation or in vitro challenge with recombinant BMPs. Adult rats were subjected to both contusion and focal ischemic SCI. One week following injury, the animals were transplanted with either EGFP- or noggin-expressing neural stem or precursor cells. Results demonstrate that noggin expression does not antagonize terminal astroglial differentiation in the engrafted stem cells. Furthermore, neutralizing endogenous BMP in the injured spinal cord significantly increased both the lesion volume and the number of infiltrating macrophages in injured spinal cords receiving noggin-expressing stem cell grafts compared with EGFP controls. These data strongly suggest that endogenous factors in the injured spinal microenvironment other than the BMPs restrict the differentiation of engrafted pluripotent neural stem cells as well as suggest other roles for BMPs in tissue protection in the injured CNS.
- Published
- 2005
- Full Text
- View/download PDF
50. Enhanced induction of RPE lineage markers in pluripotent neural stem cells engrafted into the adult rat subretinal space.
- Author
-
Enzmann V, Howard RM, Yamauchi Y, Whittemore SR, and Kaplan HJ
- Subjects
- Animals, Antigens, CD metabolism, Antigens, Differentiation, Myelomonocytic metabolism, Cell Differentiation, Cells, Cultured, Coculture Techniques, DNA-Binding Proteins metabolism, Glial Fibrillary Acidic Protein metabolism, Iodates, Keratins metabolism, Microphthalmia-Associated Transcription Factor, Neurons drug effects, Neurons metabolism, Pigment Epithelium of Eye metabolism, Pluripotent Stem Cells drug effects, Pluripotent Stem Cells metabolism, Proteins metabolism, Rats, Rats, Inbred F344, Rats, Inbred Lew, Receptor-Interacting Protein Serine-Threonine Kinases, Retina surgery, Transcription Factors metabolism, Tubulin metabolism, Biomarkers analysis, Cell Lineage, Neurons cytology, Pigment Epithelium of Eye cytology, Pluripotent Stem Cells cytology, Stem Cell Transplantation
- Abstract
Purpose: To investigate the differentiation of rat neural stem cells (rNSCs) into cells of retinal pigment epithelial (RPE) lineage both in vitro and in vivo, after subretinal transplantation into normal rats and in a sodium iodate (NaIO(3)) model of RPE loss., Methods: rNSCs prepared from the cortex of embryonic day (E)14 Fisher F344 rats were cocultured with different concentrations of vasoactive intestinal peptide (VIP), adult rat RPE cells, or neurosensory retina (NSR) for 5 days. Cell morphology and expression of RPE-specific markers (cytokeratin, CD68, microphthalmia-inducing transcription factor [MITF]) were studied. Additional antibodies used to characterize the rNSCs were markers for stem cells (nestin), immature neurons (betaIII-tubulin), astrocytes (glial fibrillary acidic protein [GFAP]), and oligodendrocytes (Rip). In in vivo studies, 10(6) green fluorescent protein [GFP]-labeled rNSCs were injected subretinally in either normal adult Lewis rats or NaIO(3)-treated rats (70 mg/mL NaIO(3) administered intravenously 7 days before transplantation)., Results: In vitro VIP-treated rNSCs changed from round cells to glia-like cells with processes that stained for both GFAP and nestin. In addition, small clusters of flattened, polygonal cells with an epithelial-cell-like shape that stained for cytokeratin and CD68 were observed. Coculture of rNSCs with RPE cells, but not with NSR, also led to cells of this phenotype. After transplantation, nestin(+) and GFP(+) rNSCs were visible subretinally as a transplant. In addition, more than 50% of transplanted rNSCs were cytokeratin(+) and CD68(+)., Conclusions: Very few rNSCs differentiate in vitro into epithelial-like cells that express RPE-specific markers. In vivo, this differentiation is remarkably enhanced after subretinal engraftment. Thus, transplantation of NSCs into the subretinal space may be a therapy for retinal diseases involving an RPE abnormality.
- Published
- 2003
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.