82 results on '"palmer, LE"'
Search Results
2. The rising trend in allergic contact dermatitis to acrylic nail products
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Jennifer Cahill, Amanda Palmer-Le, Quynh Le, and Rosemary Nixon
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Allergy ,medicine.medical_specialty ,integumentary system ,business.industry ,Dermatology ,medicine.disease ,Nail polish ,medicine.anatomical_structure ,visual_art ,Shellac ,Nail (anatomy) ,medicine ,visual_art.visual_art_medium ,skin and connective tissue diseases ,business ,Allergic contact dermatitis - Abstract
Shellac is a newly available type of long-wearing nail polish, which is becoming increasingly popular. We describe four cases of allergic contact dermatitis (ACD) to acrylates found in Shellac nail products, involving three beauticians and one consumer who purchased the product over the internet. Increasing use of these new acrylic nail products means that dermatologists need to be aware of the possibility of ACD occurring. Testing with hydroxyethyl methacrylate alone, which is included in the Australian Baseline Series, is adequate for screening for acrylate allergy.
- Published
- 2015
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3. The rising trend in allergic contact dermatitis to acrylic nail products
- Author
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Quynh, Le, Jennifer, Cahill, Amanda, Palmer-Le, and Rosemary, Nixon
- Subjects
Adult ,Young Adult ,Acrylates ,Nails ,Occupational Exposure ,Dermatitis, Allergic Contact ,Humans ,Female ,Cosmetics ,Beauty Culture ,Resins, Plant - Abstract
Shellac is a newly available type of long-wearing nail polish, which is becoming increasingly popular. We describe four cases of allergic contact dermatitis (ACD) to acrylates found in Shellac nail products, involving three beauticians and one consumer who purchased the product over the internet. Increasing use of these new acrylic nail products means that dermatologists need to be aware of the possibility of ACD occurring. Testing with hydroxyethyl methacrylate alone, which is included in the Australian Baseline Series, is adequate for screening for acrylate allergy.
- Published
- 2014
4. Angiotensin II-inhibition: effect on Alzheimer’s pathology in the aged triple transgenic mouse
- Author
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Ferrington, L, palmer, LE, Love, S, Horsburgh, KJ, Kelly, PAT, Kehoe, PG, Ferrington, L, palmer, LE, Love, S, Horsburgh, KJ, Kelly, PAT, and Kehoe, PG
- Abstract
Reducing excessive accumulation of amyloid-β (Aβ) in Alzheimer's disease (AD) is a key objective of most AD therapies, and inhibition of angiotensin-converting enzyme (ACE) may delay onset or progression of AD. The effects of an ACE-inhibitor (ACE-I) and an angiotensin II receptor blocker (ARB) on Aβ and tau pathology in a triple transgenic (3xTGAD) mouse model of AD were investigated. 9-10month 3xTGAD mice were treated with ARB, ACE-I or vehicle for 6 months. Mean arterial blood pressure (MABP) was measured periodically and mice were assessed behaviourally. Aβ, phospho-tau, amyloid precursor protein (APP) and ACE activity were analysed. MABP was significantly reduced at 2 weeks and 3 months in the ACE-I group and at 3 months in the ARB group, compared to vehicle. Neither drug altered performance of 3xTGAD mice in Morris Water Maze or T-maze, nor were Aβ, tau immunolabelling or APP levels altered. ACE-I significantly reduced ACE activity in kidney. Prolonged treatment with ACE-I or ARB does not affect Aβ or phospho-tau accumulation in brains of aged 3xTGAD mice.
- Published
- 2012
5. Angiotensin II-inhibiting drugs have no effect on intraneuronal Aβ or oligomeric Aβ levels in a triple transgenic mouse model of Alzheimer's disease
- Author
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Ferrington, L, Miners, JS, Palmer, LE, Bond, SM, Povey, JE, Kelly, PAT, Love, S, Horsburgh, KJ, Kehoe, PG, Ferrington, L, Miners, JS, Palmer, LE, Bond, SM, Povey, JE, Kelly, PAT, Love, S, Horsburgh, KJ, and Kehoe, PG
- Abstract
Background: Reducing the excessive accumulation of amyloid β-protein (Aβ) in Alzheimer's disease (AD) is a key objective of most AD therapies. Several studies suggest that pharmacological inhibition of angiotensin-converting enzyme (ACE) or its by-product angiotensin II may delay onset or progression of dementia and it has been suggested that this occurs via regulation of Aβ. Intraneuronal oligomeric accumulation of Aβ is postulated to be one of the earliest pathological events. Thus this study investigated the effect of an ACE-inhibitor, captopril, and two angiotensin II receptor blockers (ARBs), eprosartan and valsartan, on intraneuronal Aβ pathology and oligomeric Aβ levels in a triple transgenic (3xTGAD) mouse model of AD. Methods: Male, adult (3-4 month old) 3xTgAD mice (n=39) were randomly assigned to 4 treatment groups: valsartan (0.17g/l), eprosartan (0.8g/l), captopril (5g/l) or normal drinking water and the drugs given ad libitum for 2 months. Mean arterial blood pressure (MABP) was measured at baseline, at 2 weeks and at 2 months when the mice were sacrificed and the brains hemisected for analysis. One hemisphere was processed for Aβ and amyloid precursor protein (APP) immunohistochemistry and the other for biochemical measurement of oligomeric Aβ and APP. ACE activity was measured in the brain and kidney. Results: MABP was significantly reduced at 2 weeks and 2 months in the ACE-I group (p=0.0006) but was unaltered in the ARB groups compared to vehicle. Neither ACE-I nor ARB treatment altered Aβ and APP immunolabelling or the level of Aβ or APP in brain tissue homogenates. Similarly neither ACE-I nor ARB treatment altered ACE activity in either brain or kidney compared to control tissue. Conclusions: ACE-I or ARB administration over 2 months did not affect APP levels or either intraneuronal Aβ or oligomeric Aβ levels in 3xTGAD mice. While ARBs did not alter MABP, captopril did mediate reductions in MABP in the 3xTGAD mice which appeared to be independent
- Published
- 2011
6. Clusterin mRNA and protein in Alzheimer's disease.
- Author
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Baig S, Palmer LE, Owen MJ, Williams J, Kehoe PG, Love S, Baig, Shabnam, Palmer, Laura E, Owen, Michael J, Williams, Julie, Kehoe, Patrick G, and Love, Seth
- Subjects
- *
RNA metabolism , *ALZHEIMER'S disease , *BRAIN , *ENZYMES , *GLYCOPROTEINS , *PLANT proteins , *RESEARCH funding ,BRAIN metabolism - Abstract
Clusterin, a multifunctional lipoprotein is expressed in a number of tissues but expression is particularly high in the brain, where it binds to amyloid-β (Aβ), possibly facilitating Aβ transport into the bloodstream. Its concentration in peripheral blood was identified as a potential biomarker for Alzheimer's disease (AD) and predicted retention of (11)C-Pittsburgh Compound B in the temporal lobe. Single-nucleotide polymorphisms in the clusterin gene, CLU, are associated with the risk of developing AD. We measured clusterin mRNA levels in control and AD brains and investigated the relationship of the clusterin protein to soluble, insoluble, and plaque-associated Aβ. Clusterin mRNA levels were unchanged when normalized to GAPDH but modestly increased in the frontal and temporal cortex in AD in relation to NSE and MAP-2. Levels of NSE and MAP-2 mRNA were reduced in the AD frontal cortex. Clusterin protein concentration was unchanged and did not correlate with the amount of Aβ present. In the frontal cortex, clusterin concentration was higher in APOE ε4-negative brains but no effect of APOE was detected in the temporal cortex or thalamus. Overall clusterin mRNA and protein levels are unaltered in the neocortex in AD and clusterin concentration does not reflect Aβ content. The increase in clusterin noted in peripheral blood in AD may reflect increased passage of this chaperone protein across the blood-brain barrier but further work is needed to determine how CLU variants influence the development of AD. [ABSTRACT FROM AUTHOR]
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- 2012
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7. In-depth view of structure, activity, and evolution of rice chromosome 10
- Author
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Yu, Ys, Rambo, T., Currie, J., Saski, C., Kim, Hr, Collura, K., Thompson, S., Simmons, J., Yang, Tj, Nah, G., Patel, Aj, Thurmond, S., Henry, D., Oates, R., Palmer, M., Pries, G., Gibson, J., Anderson, H., Paradkar, M., Crane, L., Dale, J., Carver, Mb, Wood, T., Frisch, D., Engler, F., Soderlund, C., Palmer, Le, Tetylman, L., Nascimento, L., La Bastide, M., Spiegel, L., Ware, D., O Shaughnessy, A., Dike, S., Dedhia, N., Preston, R., Huang, E., Ferraro, K., Kuit, K., Miller, B., Zutavern, T., Katzenberger, F., Muller, S., Balija, V., Martienssen, Ra, Stein, L., Minx, P., Johnson, D., Cordum, H., Mardis, E., Cheng, Zk, Jiang, Jm, Wilson, R., Mccombie, Wr, Wing, Ra, Yuan, Qp, Shu, Oy, Liu, J., Jones, Km, Gansberger, K., Moffat, K., Hill, J., Tsitrin, T., Overton, L., Bera, J., Kim, M., Jin, Sh, Tallon, L., Ciecko, A., Pai, G., Aken, S., Utterback, T., Reidmuller, S., Bormann, J., Feldblyum, T., Hsiao, J., Zismann, V., Blunt, S., Vazeilles, A., Shaffer, T., Koo, H., Suh, B., Yang, Q., Haas, B., Peterson, J., Pertea, M., Volfovsky, N., Wortman, J., White, O., Salzberg, Sl, Fraser, Cm, Buell, Cr, Messing, J., Rentao Song, Fuks, G., Llaca, V., Kovchak, S., Young, S., Bowers, Je, Paterson, Ah, Johns, Ma, Mao, L., Pan, Hq, Dean, Ra, and Rice Chromosome 10 Sequencing Cons
8. Drinking Bottled Water
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Palmer, Leigh
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- 2014
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9. An RNZNVR 'Scheme B' entrant looks back
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Palmer, Leo
- Published
- 2004
10. Striped Tablecloth with Two Apples
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Palmer, Leigh and Smithsonian American Art Museum
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- North American, American
- Published
- 1943
11. Interior with Three Pears
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Palmer, Leigh and Smithsonian American Art Museum
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- North American, American
- Published
- 1943
12. Self-Other Balance in Context: A Quiet Ego May Be Meaningful and Adaptive in Latinx/Hispanic Cultures and Work Settings.
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Bistricky SL, Sublett LW, Moreno GL, Palmer LE, and Marek RJ
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- Humans, Female, Male, Adult, Young Adult, Workplace psychology, United States ethnology, Employment psychology, Interpersonal Relations, Self Concept, Students psychology, Adolescent, Ego, Hispanic or Latino psychology
- Abstract
Quiet ego is a relatively novel, increasingly studied, multi-dimensional concept characterized by a compassionate, interdependent worldview and an adaptive balance between self-interest and concern for others. Quiet ego has been associated with a range of characteristics that can promote relationship quality, responding effectively in the face of challenges, and greater well-being. However, it is currently unknown to what extent quiet ego translates across cultures and settings. The present research leverages cultural and organizational theories to evaluate the conceptual and structural validity of quiet ego for Latinx/Hispanic individuals in the U.S. and to examine relationships among quiet ego, work supervisor relationship quality, and goals in the workplace. Employed college student participants ( n = 831; n
Latinx/Hispanic = 305) completed an online survey, and collected data were subjected to confirmatory factor analysis and path analysis. Findings confirmed the overall structural model of quiet ego with four primary dimensions (perspective taking, inclusive identity, detached awareness, and growth-mindedness) and indicated that this structure did not differ between Latinx/Hispanic and non-Latinx/Hispanic subsamples. Further, results cohered with the proposed model suggesting that quiet ego might facilitate relationship quality with a workplace supervisor, which, in turn could foster balanced, intrinsically motivating perceptions that one's work goals benefit both oneself and others (mutual gain motivation). The study suggests that quiet ego may be a construct with meaning and utility in Latinx/Hispanic populations and in employment settings. However, further research is needed, and specific suggestions for future study are discussed., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.- Published
- 2024
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13. Ancestral β-globin gene haplotypes modify β-thalassemia severity in a mouse model.
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Lechauve C, Keith J, Fernandez AG, Khandros E, Mayberry K, Mayuranathan T, Palmer LE, Qiu X, Sheppard H, Telange R, Herz HM, and Weiss MJ
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- 2024
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14. Health and education concerns about returning to campus and online learning during the COVID-19 pandemic among US undergraduate STEM majors.
- Author
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Palmer LE, Pagoto SL, Workman D, Lewis KA, Rudin L, De Luna N, Herrera V, Brown N, Bibeau J, Arcangel K, and Waring ME
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- Female, Humans, Male, Students, Pandemics prevention & control, Universities, Education, Distance, COVID-19
- Abstract
Objective: We examined undergraduates' concerns about returning to campus and online learning from home., Participants: Undergraduates majoring in STEM (Science, Technology, Engineering, and Mathematics) at US universities/colleges., Methods: Participants completed an online survey in July 2020. We content-analyzed responses to open-ended questions about concerns about fall 2020., Results: Students ( N = 64) were 52% women, 47% low socioeconomic status (SES), and 27% non-Hispanic white. Concerns about returning to campus included student noncompliance with university COVID-19 prevention guidelines (28%), infection risk (28%), poor instructional quality (26%), inadequate university plans for preventing/handling outbreaks (25%), negative impacts on social interactions (11%), and transportation/commuting (11%). Concerns about learning from home included difficulty focusing on schoolwork (58%), lack of hands-on/experiential learning (24%), negative impacts on social interactions (19%), family/home environment (15%), concerns that online learning wastes time/money (10%), and inadequate technology/Internet access (5%)., Conclusions: Universities should address student concerns and provide resources to overcome barriers to effective learning.
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- 2023
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15. Integrome signatures of lentiviral gene therapy for SCID-X1 patients.
- Author
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Yan KK, Condori J, Ma Z, Metais JY, Ju B, Ding L, Dhungana Y, Palmer LE, Langfitt DM, Ferrara F, Throm R, Shi H, Risch I, Bhatara S, Shaner B, Lockey TD, Talleur AC, Easton J, Meagher MM, Puck JM, Cowan MJ, Zhou S, Mamcarz E, Gottschalk S, and Yu J
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- Humans, Genetic Therapy, Retroviridae genetics, T-Lymphocytes, Genetic Vectors genetics, X-Linked Combined Immunodeficiency Diseases genetics, X-Linked Combined Immunodeficiency Diseases therapy
- Abstract
Lentiviral vector (LV)-based gene therapy holds promise for a broad range of diseases. Analyzing more than 280,000 vector integration sites (VISs) in 273 samples from 10 patients with X-linked severe combined immunodeficiency (SCID-X1), we discovered shared LV integrome signatures in 9 of 10 patients in relation to the genomics, epigenomics, and 3D structure of the human genome. VISs were enriched in the nuclear subcompartment A1 and integrated into super-enhancers close to nuclear pore complexes. These signatures were validated in T cells transduced with an LV encoding a CD19-specific chimeric antigen receptor. Intriguingly, the one patient whose VISs deviated from the identified integrome signatures had a distinct clinical course. Comparison of LV and gamma retrovirus integromes regarding their 3D genome signatures identified differences that might explain the lower risk of insertional mutagenesis in LV-based gene therapy. Our findings suggest that LV integrome signatures, shaped by common features such as genome organization, may affect the efficacy of LV-based cellular therapies.
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- 2023
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16. Activation of γ-globin expression by hypoxia-inducible factor 1α.
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Feng R, Mayuranathan T, Huang P, Doerfler PA, Li Y, Yao Y, Zhang J, Palmer LE, Mayberry K, Christakopoulos GE, Xu P, Li C, Cheng Y, Blobel GA, Simon MC, and Weiss MJ
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- Humans, Chromatin, Fetal Hemoglobin biosynthesis, Fetal Hemoglobin genetics, Hypoxia genetics, Prolyl Hydroxylases metabolism, Proteasome Endopeptidase Complex metabolism, RNA, Long Noncoding, Ubiquitin metabolism, Ubiquitin-Protein Ligases genetics, Erythropoiesis, gamma-Globins biosynthesis, gamma-Globins genetics
- Abstract
Around birth, globin expression in human red blood cells (RBCs) shifts from γ-globin to β-globin, which results in fetal haemoglobin (HbF, α
2 γ2 ) being gradually replaced by adult haemoglobin (HbA, α2 β2 )1 . This process has motivated the development of innovative approaches to treat sickle cell disease and β-thalassaemia by increasing HbF levels in postnatal RBCs2 . Here we provide therapeutically relevant insights into globin gene switching obtained through a CRISPR-Cas9 screen for ubiquitin-proteasome components that regulate HbF expression. In RBC precursors, depletion of the von Hippel-Lindau (VHL) E3 ubiquitin ligase stabilized its ubiquitination target, hypoxia-inducible factor 1α (HIF1α)3,4 , to induce γ-globin gene transcription. Mechanistically, HIF1α-HIF1β heterodimers bound cognate DNA elements in BGLT3, a long noncoding RNA gene located 2.7 kb downstream of the tandem γ-globin genes HBG1 and HBG2. This was followed by the recruitment of transcriptional activators, chromatin opening and increased long-range interactions between the γ-globin genes and their upstream enhancer. Similar induction of HbF occurred with hypoxia or with inhibition of prolyl hydroxylase domain enzymes that target HIF1α for ubiquitination by the VHL E3 ubiquitin ligase. Our findings link globin gene regulation with canonical hypoxia adaptation, provide a mechanism for HbF induction during stress erythropoiesis and suggest a new therapeutic approach for β-haemoglobinopathies., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)- Published
- 2022
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17. Limitations of mouse models for sickle cell disease conferred by their human globin transgene configurations.
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Woodard KJ, Doerfler PA, Mayberry KD, Sharma A, Levine R, Yen J, Valentine V, Palmer LE, Valentine M, and Weiss MJ
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- Animals, Disease Models, Animal, Gene Editing, Humans, Mice, Transcription Factors genetics, Transgenes, gamma-Globins genetics, Anemia, Sickle Cell genetics, Anemia, Sickle Cell therapy, Fetal Hemoglobin genetics, Fetal Hemoglobin metabolism
- Abstract
We characterized the human β-like globin transgenes in two mouse models of sickle cell disease (SCD) and tested a genome-editing strategy to induce red blood cell fetal hemoglobin (HbF; α2γ2). Berkeley SCD mice contain four to 22 randomly arranged, fragmented copies of three human transgenes (HBA1, HBG2-HBG1-HBD-HBBS and a mini-locus control region) integrated into a single site of mouse chromosome 1. Cas9 disruption of the BCL11A repressor binding motif in the γ-globin gene (HBG1 and HBG2; HBG) promoters of Berkeley mouse hematopoietic stem cells (HSCs) caused extensive death from multiple double-strand DNA breaks. Long-range sequencing of Townes SCD mice verified that the endogenous Hbb genes were replaced by single-copy segments of human HBG1 and HBBS including proximal but not some distal gene-regulatory elements. Townes mouse HSCs were viable after Cas9 disruption of the HBG1 BCL11A binding motif but failed to induce HbF to therapeutic levels, contrasting with human HSCs. Our findings provide practical information on the genomic structures of two common mouse SCD models, illustrate their limitations for analyzing therapies to induce HbF and confirm the importance of distal DNA elements in human globin regulation. This article has an associated First Person interview with the first author of the paper., Competing Interests: Competing interests M.J.W. is on advisory boards for Cellarity Inc., Novartis, Graphite Bio and Forma Therapeutics. J.Y. is an equity owner of Beam Therapeutics. The other authors declare no competing financial interests. A.S. is the site principal investigator of clinical trials for genome editing of sickle cell disease sponsored by Vertex Pharmaceuticals/CRISPR Therapeutics (NCT03745287) and Novartis (NCT04443907). The industry sponsors provide funding for the clinical trial, which includes salary support. A.S. has received consultant fees from Spotlight Therapeutics, Medexus Inc. and Vertex Pharmaceuticals. He has also received research funding from CRISPR Therapeutics and honoraria from Vindico Medical Education., (© 2022. Published by The Company of Biologists Ltd.)
- Published
- 2022
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18. 20th SFG(A) Non-Trauma Module (NTM) Course.
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Walker LH, Godbee DC, Palmer LE, Share MP, and Mouri M
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- Curriculum, Humans, Emergency Medical Technicians education, Military Medicine education
- Abstract
The authors describe the 20th Special Forces Group-Airborne Non-Trauma Module refresher training for Special Forces medical sergeants and Special Operations combat medics., (2022.)
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- 2022
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19. Comfort Expressing Emotions and Suicide Ideation: Evidence of Indirect Effects Via Perceived Burdensomeness and Thwarted Belongingness.
- Author
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Kassing F, Dodd CG, Palmer LE, and Hill RM
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- Anger, Female, Humans, Male, Psychological Theory, Risk Factors, Students psychology, Surveys and Questionnaires, Young Adult, Interpersonal Relations, Suicidal Ideation
- Abstract
Objective: Emotion regulation strategies and related constructs have been implicated both as risk and protective factors in a range of mental health outcomes among young adults. To expand upon this previous research, we examined comfort expressing four discrete emotions (i.e., love, happiness, sadness, and anger) as factors that protect against suicide ideation in young adults, within the context of the interpersonal theory of suicide., Method: The sample consisted of 449 college students (73.1% female, 70.6% Hispanic, M age = 20.5 years) taking part in a larger study of mood and well-being. Students were recruited from a psychology participant pool and completed self-report measures at a single time point for course credit. Comfort expressing emotions and suicide ideation were assessed using the Measure of Verbally Expressed Emotion (MoVEE) and Adult Suicidal Ideation Questionnaire (ASIQ), respectively. Perceived burdensomeness and thwarted belongingness were assessed using the Interpersonal Needs Questionnaire (INQ)., Results: Preliminary analyses revealed negative associations between comfort expressing all four emotions and suicide ideation ( r s = -.13 to -.26). Results from structural equation modeling supported indirect effects from comfort expressing happiness and sadness to suicide ideation, via perceived burdensomeness and thwarted belongingness. An indirect effect was also identified from comfort expressing love to suicide ideation, via thwarted belongingness., Conclusions: Results suggest that comfort expressing emotions (particularly sadness and happiness) is a protective factor against suicide ideation for young adults. These findings suggest that suicide-prevention efforts may wish to focus on increasing comfort expressing emotions to trusted support networks as potential intervention targets.HIGHLIGHTSComfort expressing emotions is negatively associated with suicide ideation.Comfort expressing emotions is associated with belongingness and burdensomeness.Comfort expressing emotions may be a potential target for suicide prevention.
- Published
- 2022
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20. Activation of γ-globin gene expression by GATA1 and NF-Y in hereditary persistence of fetal hemoglobin.
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Doerfler PA, Feng R, Li Y, Palmer LE, Porter SN, Bell HW, Crossley M, Pruett-Miller SM, Cheng Y, and Weiss MJ
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- Animals, Binding Sites, COS Cells, CRISPR-Cas Systems, Cell Line, Chlorocebus aethiops, Erythroid Cells, Gene Editing methods, Gene Expression Regulation, Developmental, Humans, Promoter Regions, Genetic, Repressor Proteins genetics, Repressor Proteins metabolism, CCAAT-Binding Factor genetics, Fetal Hemoglobin genetics, GATA1 Transcription Factor genetics, gamma-Globins genetics
- Abstract
Hereditary persistence of fetal hemoglobin (HPFH) ameliorates β-hemoglobinopathies by inhibiting the developmental switch from γ-globin (HBG1/HBG2) to β-globin (HBB) gene expression. Some forms of HPFH are associated with γ-globin promoter variants that either disrupt binding motifs for transcriptional repressors or create new motifs for transcriptional activators. How these variants sustain γ-globin gene expression postnatally remains undefined. We mapped γ-globin promoter sequences functionally in erythroid cells harboring different HPFH variants. Those that disrupt a BCL11A repressor binding element induce γ-globin expression by facilitating the recruitment of nuclear transcription factor Y (NF-Y) to a nearby proximal CCAAT box and GATA1 to an upstream motif. The proximal CCAAT element becomes dispensable for HPFH variants that generate new binding motifs for activators NF-Y or KLF1, but GATA1 recruitment remains essential. Our findings define distinct mechanisms through which transcription factors and their cis-regulatory elements activate γ-globin expression in different forms of HPFH, some of which are being recreated by therapeutic genome editing., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)
- Published
- 2021
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21. A polygenic score for acute vaso-occlusive pain in pediatric sickle cell disease.
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Rampersaud E, Kang G, Palmer LE, Rashkin SR, Wang S, Bi W, Alberts NM, Anghelescu D, Barton M, Birch K, Boulos N, Brandow AM, Brooke RJ, Chang TC, Chen W, Cheng Y, Ding J, Easton J, Hodges JR, Kanne CK, Levy S, Mulder H, Patel AP, Puri L, Rosencrance C, Rusch M, Sapkota Y, Sioson E, Sharma A, Tang X, Thrasher A, Wang W, Yao Y, Yasui Y, Yergeau D, Hankins JS, Sheehan VA, Downing JR, Estepp JH, Zhang J, DeBaun M, Wu G, and Weiss MJ
- Subjects
- Child, Humans, Longitudinal Studies, Pain, Polymorphism, Single Nucleotide, Anemia, Sickle Cell complications, Anemia, Sickle Cell genetics, Fetal Hemoglobin genetics
- Abstract
Individuals with monogenic disorders can experience variable phenotypes that are influenced by genetic variation. To investigate this in sickle cell disease (SCD), we performed whole-genome sequencing (WGS) of 722 individuals with hemoglobin HbSS or HbSβ0-thalassemia from Baylor College of Medicine and from the St. Jude Children's Research Hospital Sickle Cell Clinical Research and Intervention Program (SCCRIP) longitudinal cohort study. We developed pipelines to identify genetic variants that modulate sickle hemoglobin polymerization in red blood cells and combined these with pain-associated variants to build a polygenic score (PGS) for acute vaso-occlusive pain (VOP). Overall, we interrogated the α-thalassemia deletion -α3.7 and 133 candidate single-nucleotide polymorphisms (SNPs) across 66 genes for associations with VOP in 327 SCCRIP participants followed longitudinally over 6 years. Twenty-one SNPs in 9 loci were associated with VOP, including 3 (BCL11A, MYB, and the β-like globin gene cluster) that regulate erythrocyte fetal hemoglobin (HbF) levels and 6 (COMT, TBC1D1, KCNJ6, FAAH, NR3C1, and IL1A) that were associated previously with various pain syndromes. An unweighted PGS integrating all 21 SNPs was associated with the VOP event rate (estimate, 0.35; standard error, 0.04; P = 5.9 × 10-14) and VOP event occurrence (estimate, 0.42; standard error, 0.06; P = 4.1 × 10-13). These associations were stronger than those of any single locus. Our findings provide insights into the genetic modulation of VOP in children with SCD. More generally, we demonstrate the utility of WGS for investigating genetic contributions to the variable expression of SCD-associated morbidities., (© 2021 by The American Society of Hematology.)
- Published
- 2021
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22. Association of psychological distress and religious coping tendencies in parents of children recently diagnosed with cancer: A cross-sectional study.
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Dolan JG, Hill DL, Faerber JA, Palmer LE, Barakat LP, and Feudtner C
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- Adaptation, Psychological, Child, Cross-Sectional Studies, Humans, Parents, Religion, Neoplasms, Psychological Distress
- Abstract
Purpose: Parents of children with cancer exhibit high levels of psychological distress. Parents of children with serious illness report religion and spirituality are important coping resources. We sought to describe characteristics of religion, religious coping, social support, and resiliency in parents of children newly diagnosed with cancer and examine associations between psychological distress and self-reported religious coping, religiosity, resiliency, and social support., Patients and Methods: Cross-sectional observational study of 100 parents of 81 unique children recently diagnosed with cancer. Parents provided demographic information and completed measures of psychological distress, importance of religion, religious coping, resiliency, and social support. Patients' type of tumor and intensity of treatment were collected by medical record abstraction., Results: Compared to nationally reported data for adults, parents of children with cancer reported high scores for psychological distress but similar levels of religiosity, religious coping, and resiliency. Negative religious coping (feelings of negativity related to the divine) was associated with higher levels of psychological distress. This effect was most prominent in parents who reported the highest levels of religiosity. Positive religious coping, religiosity, and social support were not associated with levels of psychological distress., Discussion: Findings confirm high levels of distress for parents of children with cancer. Negative religious coping was associated with higher levels of psychological distress but positive religious coping, religiosity, and other coping factors were not found to be significantly associated with distress. Further assessment of negative religious coping to inform interventions to promote resiliency is warranted as they may impact parental decision-making and care., (© 2021 Wiley Periodicals LLC.)
- Published
- 2021
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23. St. Jude Cloud: A Pediatric Cancer Genomic Data-Sharing Ecosystem.
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McLeod C, Gout AM, Zhou X, Thrasher A, Rahbarinia D, Brady SW, Macias M, Birch K, Finkelstein D, Sunny J, Mudunuri R, Orr BA, Treadway M, Davidson B, Ard TK, Chiao A, Swistak A, Wiggins S, Foy S, Wang J, Sioson E, Wang S, Michael JR, Liu Y, Ma X, Patel A, Edmonson MN, Wilkinson MR, Frantz AM, Chang TC, Tian L, Lei S, Islam SMA, Meyer C, Thangaraj N, Tater P, Kandali V, Ma S, Nguyen T, Serang O, McGuire I, Robison N, Gentry D, Tang X, Palmer LE, Wu G, Suh E, Tanner L, McMurry J, Lear M, Pappo AS, Wang Z, Wilson CL, Cheng Y, Meshinchi S, Alexandrov LB, Weiss MJ, Armstrong GT, Robison LL, Yasui Y, Nichols KE, Ellison DW, Bangur C, Mullighan CG, Baker SJ, Dyer MA, Miller G, Newman S, Rusch M, Daly R, Perry K, Downing JR, and Zhang J
- Subjects
- Child, Ecosystem, Hospitals, Pediatric, Humans, Anemia, Sickle Cell genetics, Cloud Computing, Genomics, Information Dissemination, Neoplasms genetics
- Abstract
Effective data sharing is key to accelerating research to improve diagnostic precision, treatment efficacy, and long-term survival in pediatric cancer and other childhood catastrophic diseases. We present St. Jude Cloud (https://www.stjude.cloud), a cloud-based data-sharing ecosystem for accessing, analyzing, and visualizing genomic data from >10,000 pediatric patients with cancer and long-term survivors, and >800 pediatric sickle cell patients. Harmonized genomic data totaling 1.25 petabytes are freely available, including 12,104 whole genomes, 7,697 whole exomes, and 2,202 transcriptomes. The resource is expanding rapidly, with regular data uploads from St. Jude's prospective clinical genomics programs. Three interconnected apps within the ecosystem-Genomics Platform, Pediatric Cancer Knowledgebase, and Visualization Community-enable simultaneously performing advanced data analysis in the cloud and enhancing the Pediatric Cancer knowledgebase. We demonstrate the value of the ecosystem through use cases that classify 135 pediatric cancer subtypes by gene expression profiling and map mutational signatures across 35 pediatric cancer subtypes. SIGNIFICANCE: To advance research and treatment of pediatric cancer, we developed St. Jude Cloud, a data-sharing ecosystem for accessing >1.2 petabytes of raw genomic data from >10,000 pediatric patients and survivors, innovative analysis workflows, integrative multiomics visualizations, and a knowledgebase of published data contributed by the global pediatric cancer community. This article is highlighted in the In This Issue feature, p. 995 ., (©2021 American Association for Cancer Research.)
- Published
- 2021
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24. 3' UTR-truncated HMGA2 overexpression induces non-malignant in vivo expansion of hematopoietic stem cells in non-human primates.
- Author
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Bonner MA, Morales-Hernández A, Zhou S, Ma Z, Condori J, Wang YD, Fatima S, Palmer LE, Janke LJ, Fowler S, Sorrentino BP, and McKinney-Freeman S
- Abstract
Vector-mediated mutagenesis remains a major safety concern for many gene therapy clinical protocols. Indeed, lentiviral-based gene therapy treatments of hematologic disease can result in oligoclonal blood reconstitution in the transduced cell graft. Specifically, clonal expansion of hematopoietic stem cells (HSCs) highly expressing HMGA2, a chromatin architectural factor found in many human cancers, is reported in patients undergoing gene therapy for hematologic diseases, raising concerns about the safety of these integrations. Here, we show for the first time in vivo multilineage and multiclonal expansion of non-human primate HSCs expressing a 3' UTR-truncated version of HMGA2 without evidence of any hematologic malignancy >7 years post-transplantation, which is significantly longer than most non-human gene therapy pre-clinical studies. This expansion is accompanied by an increase in HSC survival, cell cycle activation of downstream progenitors, and changes in gene expression led by the upregulation of IGF2BP2 , a mRNA binding regulator of survival and proliferation. Thus, we conclude that prolonged ectopic expression of HMGA2 in hematopoietic progenitors is not sufficient to drive hematologic malignancy and is not an acute safety concern in lentiviral-based gene therapy clinical protocols., Competing Interests: The authors declare no competing interests., (© 2021 The Author(s).)
- Published
- 2021
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25. FBXO11-mediated proteolysis of BAHD1 relieves PRC2-dependent transcriptional repression in erythropoiesis.
- Author
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Xu P, Scott DC, Xu B, Yao Y, Feng R, Cheng L, Mayberry K, Wang YD, Bi W, Palmer LE, King MT, Wang H, Li Y, Fan Y, Alpi AF, Li C, Peng J, Papizan J, Pruett-Miller SM, Spallek R, Bassermann F, Cheng Y, Schulman BA, and Weiss MJ
- Subjects
- Cell Line, Erythroblasts metabolism, Humans, Proteolysis, Chromosomal Proteins, Non-Histone metabolism, Erythropoiesis physiology, F-Box Proteins metabolism, Gene Expression Regulation physiology, Polycomb Repressive Complex 2 metabolism, Protein-Arginine N-Methyltransferases metabolism
- Abstract
The histone mark H3K27me3 and its reader/writer polycomb repressive complex 2 (PRC2) mediate widespread transcriptional repression in stem and progenitor cells. Mechanisms that regulate this activity are critical for hematopoietic development but are poorly understood. Here we show that the E3 ubiquitin ligase F-box only protein 11 (FBXO11) relieves PRC2-mediated repression during erythroid maturation by targeting its newly identified substrate bromo adjacent homology domain-containing 1 (BAHD1), an H3K27me3 reader that recruits transcriptional corepressors. Erythroblasts lacking FBXO11 are developmentally delayed, with reduced expression of maturation-associated genes, most of which harbor bivalent histone marks at their promoters. In FBXO11-/- erythroblasts, these gene promoters bind BAHD1 and fail to recruit the erythroid transcription factor GATA1. The BAHD1 complex interacts physically with PRC2, and depletion of either component restores FBXO11-deficient erythroid gene expression. Our studies identify BAHD1 as a novel effector of PRC2-mediated repression and reveal how a single E3 ubiquitin ligase eliminates PRC2 repression at many developmentally poised bivalent genes during erythropoiesis., (© 2021 by The American Society of Hematology.)
- Published
- 2021
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26. Optimizing lentiviral vector transduction of hematopoietic stem cells for gene therapy.
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Jang Y, Kim YS, Wielgosz MM, Ferrara F, Ma Z, Condori J, Palmer LE, Zhao X, Kang G, Rawlings DJ, Zhou S, and Ryu BY
- Subjects
- Animals, Antigens, CD34, Genetic Therapy, Genetic Vectors genetics, Hematopoietic Stem Cells, Humans, Mice, Transduction, Genetic, Hematopoietic Stem Cell Transplantation, Lentivirus genetics
- Abstract
Autologous gene therapy using lentiviral vectors (LVs) holds promise for treating monogenetic blood diseases. However, clinical applications can be limited by suboptimal hematopoietic stem cell (HSC) transduction and insufficient quantities of available vector. We recently reported gene therapy for X-linked severe combined immunodeficiency using a protocol in which patient CD34
+ cells were incubated with two successive transductions. Here we describe an improved protocol for LV delivery to CD34+ cells that simplifies product manipulation, reduces vector consumption, and achieves greater vector copy number (VCN) of repopulating HSCs in mouse xenotransplantation assays. Notable findings include the following: (1) the VCN of CD34+ cells measured shortly after transduction did not always correlate with the VCN of repopulating HSCs after xenotransplantation; (2) single-step transduction at higher CD34+ cell concentrations (2-4 × 106 /ml) conserved LV without compromising HSC VCN; (3) poloxamer F108 (LentiBOOST) increased HSC VCN by two- to threefold (average from three donors); (4) although LentiBOOST + prostaglandin E2 combination further increased VCN in vitro, the VCN observed in vivo were similar to LentiBOOST alone; (5) cyclosporine H increased the HSC VCN to a similar or greater extent with LentiBOOST in vivo. Our findings delineate an improved protocol to increase the VCN of HSCs after CD34+ cell transduction with clinically relevant LVs.- Published
- 2020
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27. Operational K9s in the COVID-19 World.
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Gray BO, St George D, Cativo M, Tagore A, Ariyaprakai N, and Palmer LE
- Subjects
- Animals, Betacoronavirus, COVID-19, Coronavirus Infections prevention & control, Humans, Pandemics prevention & control, Pneumonia, Viral prevention & control, SARS-CoV-2, Coronavirus Infections transmission, Coronavirus Infections veterinary, Dogs virology, Military Personnel, Pandemics veterinary, Pneumonia, Viral transmission, Pneumonia, Viral veterinary
- Abstract
Severe acute respiratory syndrome coronavirus 2 (SARSCov- 2) is hypothesized to have originated from a spillover event from an animal reservoir. This has raised many questions, with an important one being whether the widely disseminated coronavirus disease 2019 (COVID-19) is transmissible to other animal species. SARS-CoV-2 is primarily transmitted person to person. K9-to-human transmission, although theoretically possible via fomites, is considered minimal, if at all, and there have been no reported cases of K9-to-human transmission. Human-to-K9 transmission, although rare, seems more likely; however, in only one case has a K9 been suspected to have displayed symptoms of COVID-19. Preparation, decontamination, hand hygiene, and distancing remain the key factors in reducing transmission of the virus. The information presented is applicable to personnel operating within the military conventional and Special Operation Forces as well as civilian Tactical Emergency Medical Services communities who may have the responsibility of supporting an operational K9., (2020.)
- Published
- 2020
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28. Canine Tactical Combat Casualty Care (K9TCCC) Guidelines.
- Author
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Edwards TH, Palmer LE, Baxter RL, Sager TC, Coisman JG, Brown JC, George C, and McGraw AC
- Subjects
- Animals, Dogs, Practice Guidelines as Topic, Veterinary Service, Military, War-Related Injuries therapy, War-Related Injuries veterinary
- Abstract
First introduced in 1996, Tactical Combat Casualty Care (TCCC) redefined prehospital, point-of-injury (POI), battlefield trauma care for the human combat casualty. Today, many consider TCCC as one of the most influential interventions for reducing combat-related case fatality rates from preventable deaths in human combat casualties. Throughout history, Military Working Dogs (MWDs) have proved and continue to prove themselves as force multipliers in the success of many military operations. Since the start of the Global War on Terror in 2001, these elite canine operators have experienced an upsurge in combat-related deployments, placing them at a higher risk for combat-related injuries. Until recently, consensus- based Canine-TCCC (K9TCCC) guidelines for POI battlefield trauma care did not exist for the MWD, leaving a critical knowledge gap significantly jeopardizing MWD survival. In 2019, the Canine Combat Casualty Care Committee was formed as an affiliate of the Committee on Tactical Combat Casualty Care with the intent of developing evidence- based, best practice K9TCCC guidelines. Modeled after the same principles of the human TCCC, K9TCCC focuses on simple, evidence-based, field-proven medical interventions to eliminate preventable deaths and to improve MWD survival. Customized for the battlefield, K9TCCC uniquely adapts the techniques of TCCC to compensate for canine-specific anatomic and physiological differences., (2020.)
- Published
- 2020
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29. Regulation of gene expression by miR-144/451 during mouse erythropoiesis.
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Xu P, Palmer LE, Lechauve C, Zhao G, Yao Y, Luan J, Vourekas A, Tan H, Peng J, Schuetz JD, Mourelatos Z, Wu G, Weiss MJ, and Paralkar VR
- Subjects
- Alkyl and Aryl Transferases genetics, Animals, Membrane Proteins genetics, Mice, Mice, Knockout, Alkyl and Aryl Transferases biosynthesis, Erythropoiesis genetics, Gene Expression Regulation genetics, Membrane Proteins biosynthesis, MicroRNAs genetics
- Abstract
The microRNA (miRNA) locus miR-144/451 is abundantly expressed in erythrocyte precursors, facilitating their terminal maturation and protecting against oxidant stress. However, the full repertoire of erythroid miR-144/451 target messenger RNAs (mRNAs) and associated cellular pathways is unknown. In general, the numbers of mRNAs predicted to be targeted by an miRNA vary greatly from hundreds to thousands, and are dependent on experimental approaches. To comprehensively and accurately identify erythroid miR-144/451 target mRNAs, we compared gene knockout and wild-type fetal liver erythroblasts by RNA sequencing, quantitative proteomics, and RNA immunoprecipitation of Argonaute (Ago), a component of the RNA-induced silencing complex that binds miRNAs complexed to their target mRNAs. Argonaute bound ∼1400 erythroblast mRNAs in a miR-144/451-dependent manner, accounting for one-third of all Ago-bound mRNAs. However, only ∼100 mRNAs were stabilized after miR-144/451 loss. Thus, miR-144 and miR-451 deregulate <10% of mRNAs that they bind, a characteristic that likely applies generally to other miRNAs. Using stringent selection criteria, we identified 53 novel miR-144/451 target mRNAs. One of these, Cox10 , facilitates the assembly of mitochondrial electron transport complex IV. Loss of miR-144/451 caused increased Cox10 mRNA and protein, accumulation of complex IV, and increased mitochondrial membrane potential with no change in mitochondrial mass. Thus, miR-144/451 represses mitochondrial respiration during erythropoiesis by inhibiting the production of Cox10., (© 2019 by The American Society of Hematology.)
- Published
- 2019
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30. Concepts of Prehospital Advanced Airway Management in the Operational K9: A Focus on Cricothyrotomy.
- Author
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Palmer LE
- Subjects
- Airway Obstruction surgery, Animals, Dogs, Tracheostomy methods, Airway Obstruction veterinary, Dog Diseases surgery, Emergency Medical Services, Tracheostomy veterinary, Veterinary Service, Military
- Abstract
Similar to people, airway obstruction is a potentially preventable cause of combat and line of duty death for civilian law enforcement Operational K9s (OpK9) and military working dogs (MWD). Basic (i.e., body positioning, manual maneuvers, bag-valve-mask ventilation) and advanced (i.e., endotracheal intubation, surgical airways) airway techniques are designed to establish a patent airway, oxygenate and ventilate, and protect from aspiration. A surgical airway (cricothyrotomy [CTT] or tracheostomy [TT]) is warranted for difficult airway scenarios in which less invasive means fail to open an airway (aka "Cannot intubate, cannot oxygenate"). In people, the surgical CTT is the preferred surgical airway procedure; most human prehospital providers are not even trained on the TT. Currently, only the TT is described in the veterinary literature as an emergent surgical airway for MWDs. This article describes the novel approach of instituting the surgical CTT for managing the canine difficult airway. The information provided is applicable to personnel operating within the US Special Operations Command as well as civilian tactical emergency medical services that may have the responsibility of providing medical care to an OpK9 or MWD., (2019.)
- Published
- 2019
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31. Picture This: Management of Canine Pyotraumatic Dermatitis (a.k.a., Hot Spot).
- Author
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Palmer LE
- Subjects
- Animals, Dogs, Military Medicine, Military Personnel, Veterinary Medicine, Dermatitis diagnosis, Dermatitis pathology, Dermatitis therapy, Dermatitis veterinary, Skin injuries, Skin pathology
- Abstract
Pyotraumatic dermatitis (a.k.a., hot spot) is a rapidly developing, superficial, moist, exudative dermatitis commonly induced by self-inflicted trauma. Although not acutely life threatening, these lesions are extremely pruritic and distracting and significantly interfere with the canine's operational effectiveness and ability to stay on task. The review discusses a case, including clinical presentation, diagnosis, treatment, and prognosis., (2018.)
- Published
- 2018
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32. Nfix Promotes Survival of Immature Hematopoietic Cells via Regulation of c-Mpl.
- Author
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Hall T, Walker M, Ganuza M, Holmfeldt P, Bordas M, Kang G, Bi W, Palmer LE, Finkelstein D, and McKinney-Freeman S
- Subjects
- Animals, Humans, Mice, Signal Transduction, Hematopoietic Stem Cells metabolism, NFI Transcription Factors metabolism, Receptors, Thrombopoietin metabolism
- Abstract
Hematopoietic stem and progenitor cells (HSPCs) are necessary for life-long blood production and replenishment of the hematopoietic system during stress. We recently reported that nuclear factor I/X (Nfix) promotes HSPC survival post-transplant. Here, we report that ectopic expression of Nfix in primary mouse HSPCs extends their ex vivo culture from about 20 to 40 days. HSPCs overexpressing Nfix display hypersensitivity to supportive cytokines and reduced apoptosis when subjected to cytokine deprivation relative to controls. Ectopic Nfix resulted in elevated levels of c-Mpl transcripts and cell surface protein on primary murine HSPCs as well as increased phosphorylation of STAT5, which is known to be activated down-stream of c-MPL. Blocking c-MPL signaling by removal of thrombopoietin or addition of a c-MPL neutralizing antibody negated the antiapoptotic effect of Nfix overexpression on cultured HSPCs. Furthermore, NFIX was capable of binding to and transcriptionally activating a proximal c-Mpl promoter fragment. In sum, these data suggest that NFIX-mediated upregulation of c-Mpl transcription can protect primitive hematopoietic cells from stress ex vivo. Stem Cells 2018;36:943-950., (© AlphaMed Press 2018.)
- Published
- 2018
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33. PI3K orchestration of the in vivo persistence of chimeric antigen receptor-modified T cells.
- Author
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Zheng W, O'Hear CE, Alli R, Basham JH, Abdelsamed HA, Palmer LE, Jones LL, Youngblood B, and Geiger TL
- Subjects
- Cell Differentiation drug effects, Cell Line, Tumor, Humans, Lymphocyte Activation drug effects, Phosphoinositide-3 Kinase Inhibitors, Sialic Acid Binding Ig-like Lectin 3 pharmacology, Sialic Acid Binding Ig-like Lectin 3 therapeutic use, T-Lymphocytes, Tumor Burden drug effects, Immunotherapy, Adoptive methods, Leukemia, Myeloid, Acute therapy, Phosphatidylinositol 3-Kinases metabolism, Receptors, Chimeric Antigen therapeutic use
- Abstract
In vivo persistence of chimeric antigen receptor (CAR)-modified T cells correlates with therapeutic efficacy, yet CAR-specific factors that support persistence are not well resolved. Using a CD33-specific CAR in an acute myeloid leukemia (AML) model, we show how CAR expression alters T cell differentiation in a ligand independent manner. Ex vivo expanded CAR-T cells demonstrated decreased naïve and stem memory populations and increased effector subsets relative to vector-transduced control cells. This was associated with reduced in vivo persistence. Decreased persistence was not due to specificity or tumor presence, but to pre-transfer tonic signaling through the CAR CD3ζ ITAMs. We identified activation of the PI3K pathway in CD33 CAR-T cells as responsible. Treatment with a PI3K inhibitor modulated the differentiation program of CAR-T cells, preserved a less differentiated state without affecting T cell expansion, and improved in vivo persistence and reduced tumor burden. These results resolve mechanisms by which tonic signaling of CAR-T cells modulates their fate, and identifies a novel pharmacologic approach to enhance the durability of CAR-T cells for immunotherapy.
- Published
- 2018
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34. Prehospital Care of Canine Gastric Dilatation and Volvulus.
- Author
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Palmer LE
- Subjects
- Animals, Dilatation, Pathologic diagnosis, Dilatation, Pathologic therapy, Dilatation, Pathologic veterinary, Dogs, Male, Stomach pathology, Stomach Volvulus diagnosis, United States, Veterinary Service, Military, Emergency Treatment, Stomach Volvulus therapy, Stomach Volvulus veterinary
- Abstract
The intent of the Operational K9 (OpK9) ongoing series is to provide the Special Operations Medical Association community with clinical concepts and scientific information on preventive and prehospital emergency care relevant to the OpK9. Often the only medical support immediately available for an injured or ill OpK9 in the field is their handler or the human Special Operations Combat Medic or civilian tactical medic attached to the team (e.g., Pararescueman, 18D, SWAT medic). The information is applicable to personnel operating within the US Special Operations Command as well as civilian Tactical Emergency Medical Services communities that may have the responsibility of supporting an OpK9., (2018.)
- Published
- 2018
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- View/download PDF
35. Clinical Update: Concepts of Prehospital Traumatic Hemorrhage Control in the Operational K9.
- Author
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Palmer LE
- Subjects
- Animals, Bandages veterinary, Dogs, Exsanguination prevention & control, Exsanguination veterinary, Hemostatics therapeutic use, First Aid veterinary, Hemorrhage prevention & control, Hemorrhage veterinary, Veterinary Service, Military
- Abstract
Major trauma often involves varying degrees of hemorrhage. Left unattended, any amount of trauma-induced hemorrhage may rapidly become life threatening. Similar to humans, Operational canines (OpK9s) can suffer penetrating trauma and blunt trauma that lead to compressible and noncompressible hemorrhage. Preserving organ function and saving the life of a massively bleeding OpK9 require the implementation of immediate and effective hemostatic measures. Effective hemorrhage control interventions for the exsanguinating OpK9 are similar to those for humans: direct pressure, wound packing, hemostatic agents and devices, pressure bandage, and, possibly, tourniquet application. Although tourniquet application is a life-saving intervention in humans experiencing extremity hemorrhage, it is not considered a necessary, immediate-action life-saving intervention for canines with extremity injuries. This article provides a brief description of the basic methods for identifying life-threatening hemorrhage and achieving immediate hemostasis in the bleeding OpK9 during the prehospital period., (2018.)
- Published
- 2018
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- View/download PDF
36. Effect of laparotomy on the pituitary-adrenal axis in dogs.
- Author
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Skovira EJ, Behrend EN, Martin LG, Palmer LE, Kemppainen RJ, and Lee HP
- Subjects
- Adrenocorticotropic Hormone blood, Aldosterone blood, Animals, Dogs surgery, Female, Hydrocortisone blood, Male, Pituitary-Adrenal System drug effects, Pituitary-Adrenal System surgery, Reference Values, Dogs blood, Laparotomy veterinary, Pituitary-Adrenal System physiology
- Abstract
OBJECTIVE To assess effects of major abdominal surgery on serum cortisol and aldosterone and plasma canine ACTH (cACTH) concentrations. ANIMALS 39 healthy dogs undergoing laparotomy during veterinary student surgical laboratories. PROCEDURES Blood samples were obtained before and at completion of surgery. Serum cortisol and aldosterone and plasma cACTH concentrations were measured by use of validated radioimmunoassays. Changes in concentrations (postoperative concentration minus preoperative concentration) were calculated. Data were analyzed by use of the Wilcoxon signed rank test, Pearson correlation analysis, and Mann-Whitney rank sum test. RESULTS Cortisol, aldosterone, and cACTH concentrations increased significantly from before to after surgery. Although cortisol and aldosterone concentrations increased in almost all dogs, cACTH concentrations decreased in 6 of 32 (19%) dogs. All dogs had preoperative cortisol concentrations within the reference range, but 24 of 39 (62%) dogs had postoperative concentrations above the reference range. A correlation between the change in cACTH concentration and the change in cortisol concentration was not detected. CONCLUSIONS AND CLINICAL RELEVANCE Laparotomy caused a significant increase in serum cortisol and aldosterone concentrations. In most dogs, but not all dogs, plasma cACTH concentrations increased. Lack of correlation between the change in cACTH concentration and the change in cortisol concentration suggested that increased postoperative cortisol concentrations may have been attributable to ACTH-independent mechanisms, an early ACTH increase that caused a sustained cortisol release, or decreased cortisol clearance. Further studies are indicated to evaluate the effects of various anesthetic protocols and minimally invasive surgical techniques on the stress response.
- Published
- 2017
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37. TacMed Updates: K9 Tactical Emergency Casualty Care Direct Threat Care Guidelines.
- Author
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Palmer LE and Yee A
- Subjects
- Animals, Dogs, Humans, Emergency Medical Services, Military Medicine, Practice Guidelines as Topic, War-Related Injuries veterinary
- Published
- 2017
- Full Text
- View/download PDF
38. Angiotensin-III is Increased in Alzheimer's Disease in Association with Amyloid-β and Tau Pathology.
- Author
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Kehoe PG, Hibbs E, Palmer LE, and Miners JS
- Subjects
- Aged, Aged, 80 and over, Analysis of Variance, CD13 Antigens metabolism, Cohort Studies, Enzyme-Linked Immunosorbent Assay, Female, Glutamyl Aminopeptidase metabolism, Humans, Male, Alzheimer Disease genetics, Alzheimer Disease pathology, Amyloid beta-Peptides metabolism, Angiotensin III metabolism, Frontal Lobe metabolism, tau Proteins metabolism
- Abstract
Hyperactivity of the renin-angiotensin system (RAS) is associated with the pathogenesis of Alzheimer's disease (AD) believed to be mediated by angiotensin-II (Ang-II) activation of the angiotensin type 1 receptor (AT1R). We previously showed that angiotensin-converting enzyme-1 (ACE-1) activity, the rate-limiting enzyme in the production of Ang-II, is increased in human postmortem brain tissue in AD. Angiotensin-III (Ang-III) activates the AT1R and angiotensin type-2 receptor (AT2R), but its potential role in the pathophysiology of AD remains unexplored. We measured Ang-II and Ang-III levels by ELISA, and the levels and activities of aminopeptidase-A (AP-A) and aminopeptidase-N (AP-N) (responsible for the production and metabolism of Ang-III, respectively) in human postmortem brain tissue in the mid-frontal cortex (Brodmann area 9) in a cohort of AD (n = 90) and age-matched non-demented controls (n = 59), for which we had previous measurements of ACE-1 activity, Aβ level, and tau pathology (also in the mid-frontal cortex). We found that both Ang-II and Ang-III levels were significantly higher in AD compared to age-matched controls and that Ang-III, rather than Ang-II, was strongly associated with Aβ load and tau load. Levels of AP-A were significantly reduced in AD but AP-A enzyme activity was unchanged whereas AP-N activity was reduced in AD but AP-N protein level was unchanged. Together, these data indicate that the APA/Ang-III/APN/Ang-IV/AT4R pathway is dysregulated and that elevated Ang-III could contribute to the pathogenesis of AD.
- Published
- 2017
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39. Clinical Update: The Risk of Opioid Toxicity and Naloxone Use in Operational K9s.
- Author
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Palmer LE and Gautier A
- Subjects
- Analgesics, Opioid metabolism, Analgesics, Opioid pharmacology, Animals, Dogs, Drug Overdose diagnosis, Illicit Drugs metabolism, Illicit Drugs pharmacology, Naloxone administration & dosage, Narcotic Antagonists administration & dosage, Receptors, Opioid metabolism, Risk Factors, Analgesics, Opioid poisoning, Dog Diseases chemically induced, Drug Overdose drug therapy, Drug Overdose veterinary, Illicit Drugs poisoning, Naloxone therapeutic use, Narcotic Antagonists therapeutic use
- Abstract
The increasing use of opioids (e.g., fentanyl, carfentanil) for illicit drug manufacturing poses a potential life-threatening hazard to law enforcement officers and first responders (e.g., EMS, fire and rescue) who may unknowingly come into contact with these drugs during the course of their daily activities. Similarly, Operational canines (OpK9s) of all disciplines-detection (drug, explosive, accelerant), patrol, tracking, search and rescue, and others-are at risk for accidental illicit opioid exposure. The most serious adverse effect of opioid exposure is respiratory depression leading to slow, shallow breathing or complete cessation of voluntary breathing (respiratory arrest). Naloxone, an opioid antagonist, is the antidote for reversing the effects of an opioid overdose in both humans and OpK9s. This clinical update describes the potential risks associated with opioid exposure as well as the use of naloxone as it pertains to the OpK9., (2017.)
- Published
- 2017
- Full Text
- View/download PDF
40. Angiotensin-converting enzyme 2 is reduced in Alzheimer's disease in association with increasing amyloid-β and tau pathology.
- Author
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Kehoe PG, Wong S, Al Mulhim N, Palmer LE, and Miners JS
- Subjects
- Aged, Aged, 80 and over, Alzheimer Disease genetics, Amyloid beta-Peptides metabolism, Analysis of Variance, Angiotensin I metabolism, Angiotensin II genetics, Apolipoproteins E genetics, Autopsy, Case-Control Studies, Cohort Studies, Female, Humans, Male, Peptide Fragments metabolism, Peptidyl-Dipeptidase A genetics, Peptidyl-Dipeptidase A metabolism, Polymorphism, Single Nucleotide drug effects, Alzheimer Disease pathology, Angiotensin II metabolism, Brain metabolism, Statistics as Topic, tau Proteins metabolism
- Abstract
Background: Hyperactivity of the classical axis of the renin-angiotensin system (RAS), mediated by angiotensin II (Ang II) activation of the angiotensin II type 1 receptor (AT1R), is implicated in the pathogenesis of Alzheimer's disease (AD). Angiotensin-converting enzyme-2 (ACE-2) degrades Ang II to angiotensin 1-7 (Ang (1-7)) and counter-regulates the classical axis of RAS. We have investigated the expression and distribution of ACE-2 in post-mortem human brain tissue in relation to AD pathology and classical RAS axis activity., Methods: We measured ACE-2 activity by fluorogenic peptide substrate assay in mid-frontal cortex (Brodmann area 9) in a cohort of AD (n = 90) and age-matched non-demented controls (n = 59) for which we have previous data on ACE-1 activity, amyloid β (Aβ) level and tau pathology, as well as known ACE1 (rs1799752) indel polymorphism, apolipoprotein E (APOE) genotype, and cerebral amyloid angiopathy severity scores., Results: ACE-2 activity was significantly reduced in AD compared with age-matched controls (P < 0.0001) and correlated inversely with levels of Aβ (r = -0.267, P < 0.001) and phosphorylated tau (p-tau) pathology (r = -0.327, P < 0.01). ACE-2 was reduced in individuals possessing an APOE ε4 allele (P < 0.05) and was associated with ACE1 indel polymorphism (P < 0.05), with lower ACE-2 activity in individuals homozygous for the ACE1 insertion AD risk allele. ACE-2 activity correlated inversely with ACE-1 activity (r = -0.453, P < 0.0001), and the ratio of ACE-1 to ACE-2 was significantly elevated in AD (P < 0.0001). Finally, we show that the ratio of Ang II to Ang (1-7) (a proxy measure of ACE-2 activity indicating conversion of Ang II to Ang (1-7)) is reduced in AD., Conclusions: Together, our findings indicate that ACE-2 activity is reduced in AD and is an important regulator of the central classical ACE-1/Ang II/AT1R axis of RAS, and also that dysregulation of this pathway likely plays a significant role in the pathogenesis of AD.
- Published
- 2016
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41. Executive functions predict conceptual learning of science.
- Author
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Rhodes SM, Booth JN, Palmer LE, Blythe RA, Delibegovic M, and Wheate NJ
- Subjects
- Adolescent, Child, Female, Humans, Male, Chemistry education, Concept Formation physiology, Executive Function physiology, Learning physiology, Memory, Short-Term physiology
- Abstract
We examined the relationship between executive functions and both factual and conceptual learning of science, specifically chemistry, in early adolescence. Sixty-three pupils in their second year of secondary school (aged 12-13 years) participated. Pupils completed tasks of working memory (Spatial Working Memory), inhibition (Stop-Signal), attention set-shifting (ID/ED), and planning (Stockings of Cambridge), from the CANTAB. They also participated in a chemistry teaching session, practical, and assessment on the topic of acids and alkalis designed specifically for this study. Executive function data were related to (1) the chemistry assessment which included aspects of factual and conceptual learning and (2) a recent school science exam. Correlational analyses between executive functions and both the chemistry assessment and science grades revealed that science achievements were significantly correlated with working memory. Linear regression analysis revealed that visuospatial working memory ability was predictive of chemistry performance. Interestingly, this relationship was observed solely in relation to the conceptual learning condition of the assessment highlighting the role of executive functions in understanding and applying knowledge about what is learned within science teaching., (© 2016 The British Psychological Society.)
- Published
- 2016
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- View/download PDF
42. The Operational Canine and K9 Tactical Emergency Casualty Care Initiative.
- Author
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Palmer LE, Maricle R, and Brenner JA
- Subjects
- Animals, Dogs, Guidelines as Topic, Humans, Law Enforcement, First Aid veterinary, Veterinary Service, Military, Wounds and Injuries veterinary
- Abstract
Background: Approximately 20% to 25% of trauma-related, prehospital fatalities in humans are due to preventable deaths. Data are lacking, however, on the nature and the prevalence of operational canine (OC) prehospital deaths. It is plausible that OCs engaged in high-threat operations are also at risk for suffering some type of preventable death. Tactical Combat Casualty Care has significantly reduced human fatality rates on the battlefield. Standardized guidelines specifically for prehospital trauma care have not been developed for the OC caregiver. An initiation has been approved by the Committee for Tactical Emergency Casualty Care to form a K9-Tactical Emergency Casualty Care (TECC) working group to develop such guidelines., Significance: The intent of the K9-TECC initiative is to form best practice recommendations for the civilian high-risk OC caregiver. These recommendations are to focus on interventions that (1) eliminate the major causes of canine out-of-hospital preventable deaths, (2) are easily learned and applied by any civilian first responder, and (2) minimize resource consumption., (2015.)
- Published
- 2015
- Full Text
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43. Aβ degradation or cerebral perfusion? Divergent effects of multifunctional enzymes.
- Author
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Miners JS, Palmer JC, Tayler H, Palmer LE, Ashby E, Kehoe PG, and Love S
- Abstract
There is increasing evidence that deficient clearance of β-amyloid (Aβ) contributes to its accumulation in late-onset Alzheimer disease (AD). Several Aβ-degrading enzymes, including neprilysin (NEP), endothelin-converting enzyme (ECE), and angiotensin-converting enzyme (ACE) reduce Aβ levels and protect against cognitive impairment in mouse models of AD. In post-mortem human brain tissue we have found that the activity of these Aβ-degrading enzymes rise with age and increases still further in AD, perhaps as a physiological response that helps to minimize the build-up of Aβ. ECE-1/-2 and ACE are also rate-limiting enzymes in the production of endothelin-1 (ET-1) and angiotensin II (Ang II), two potent vasoconstrictors, increases in the levels of which are likely to contribute to reduced blood flow in AD. This review considers the possible interdependence between Aβ-degrading enzymes, ischemia and Aβ in AD: ischemia has been shown to increase Aβ production both in vitro and in vivo, whereas increased Aβ probably enhances ischemia by vasoconstriction, mediated at least in part by increased ECE and ACE activity. In contrast, NEP activity may help to maintain cerebral perfusion, by reducing the accumulation of Aβ in cerebral blood vessels and lessening its toxicity to vascular smooth muscle cells. In assessing the role of Aβ-degrading proteases in the pathogenesis of AD and, particularly, their potential as therapeutic agents, it is important to bear in mind the multifunctional nature of these enzymes and to consider their effects on other substrates and pathways.
- Published
- 2014
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44. FeoB-mediated uptake of iron by Francisella tularensis.
- Author
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Thomas-Charles CA, Zheng H, Palmer LE, Mena P, Thanassi DG, and Furie MB
- Subjects
- Animals, Cell Line, Disease Models, Animal, Hepatocytes microbiology, Humans, Macrophages metabolism, Macrophages microbiology, Mice, Oligonucleotide Array Sequence Analysis, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Virulence physiology, Cation Transport Proteins metabolism, Francisella tularensis metabolism, Iron metabolism, Tularemia metabolism
- Abstract
Francisella tularensis, the bacterial cause of tularemia, infects the liver and replicates in hepatocytes in vivo and in vitro. However, the factors that govern adaptation of F. tularensis to the intrahepatocytic niche have not been identified. Using cDNA microarrays, we determined the transcriptional profile of the live vaccine strain (LVS) of F. tularensis grown in the FL83B murine hepatocytic cell line compared to that of F. tularensis cultured in broth. The fslC gene of the fsl operon was the most highly upregulated. Deletion of fslC eliminated the ability of the LVS to produce siderophore, which is involved in uptake of ferric iron, but it did not impair its growth in hepatocytes, A549 epithelial cells, or macrophages. Therefore, we sought an alternative means by which F. tularensis might obtain iron. Deletion of feoB, which encodes a putative ferrous iron transporter, retarded replication of the LVS in iron-restricted media, reduced its growth in hepatocytic and epithelial cells, and impaired its acquisition of iron. Survival of mice infected intradermally with a lethal dose of the LVS was slightly improved by deletion of fslC but was not altered by loss of feoB. However, the ΔfeoB mutant showed diminished ability to colonize the lungs, liver, and spleen of mice that received sublethal inocula. Thus, FeoB represents a previously unidentified mechanism for uptake of iron by F. tularensis. Moreover, failure to produce a mutant strain lacking both feoB and fslC suggests that FeoB and the proteins of the fsl operon are the only major means by which F. tularensis acquires iron.
- Published
- 2013
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45. A transposon site hybridization screen identifies galU and wecBC as important for survival of Yersinia pestis in murine macrophages.
- Author
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Klein KA, Fukuto HS, Pelletier M, Romanov G, Grabenstein JP, Palmer LE, Ernst R, and Bliska JB
- Subjects
- Animals, Bacterial Proteins genetics, Carbohydrate Dehydrogenases genetics, Carbohydrate Epimerases genetics, Carbohydrate Epimerases metabolism, Cell Line, Gene Expression Regulation, Bacterial, Mice, Microbial Viability, Mutagenesis, Insertional, UTP-Glucose-1-Phosphate Uridylyltransferase genetics, Yersinia pestis genetics, Yersinia pestis growth & development, Bacterial Proteins metabolism, Carbohydrate Dehydrogenases metabolism, DNA Transposable Elements, Macrophages microbiology, Plague microbiology, UTP-Glucose-1-Phosphate Uridylyltransferase metabolism, Yersinia pestis enzymology
- Abstract
Yersinia pestis is able to survive and replicate within murine macrophages. However, the mechanism by which Y. pestis promotes its intracellular survival is not well understood. To identify genes that are important for Y. pestis survival in macrophages, a library comprised of ∼31,500 Y. pestis KIM6+ transposon insertion mutants (input pool) was subjected to negative selection in primary murine macrophages. Genes underrepresented in the output pool of surviving bacteria were identified by transposon site hybridization to DNA oligonucleotide microarrays. The screen identified several genes known to be important for survival of Y. pestis in macrophages, including phoPQ and members of the PhoPQ regulon (e.g., pmrF). In addition, genes predicated to encode a glucose-1-phosphate uridylyltransferase (galU), a UDP-N-acetylglucosamine 2-epimerase (wecB) and a UDP-N-acetyl-d-mannosamine dehydrogenase (wecC) were identified in the screen. Viable-count assays demonstrated that a KIM6+ galU mutant and a KIM6+ wecBC mutant were defective for survival in murine macrophages. The galU mutant was studied further because of its strong phenotype. The KIM6+ galU mutant exhibited increased susceptibility to the antimicrobial peptides polymyxin B and cathelicidin-related antimicrobial peptide (CRAMP). Polyacrylamide gel electrophoresis demonstrated that the lipooligosaccharide (LOS) of the galU mutant migrated faster than the LOS of the parent KIM6+, suggesting the core was truncated. In addition, the analysis of LOS isolated from the galU mutant by mass spectrometry showed that aminoarabinose modification of lipid A is absent. Therefore, addition of aminoarabinose to lipid A and complete LOS core (galU), as well as enterobacterial common antigen (wecB and wecC), is important for survival of Y. pestis in macrophages.
- Published
- 2012
- Full Text
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46. Angiotensin II-inhibition: effect on Alzheimer's pathology in the aged triple transgenic mouse.
- Author
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Ferrington L, Palmer LE, Love S, Horsburgh KJ, Kelly PA, and Kehoe PG
- Abstract
Reducing excessive accumulation of amyloid-β (Aβ) in Alzheimer's disease (AD) is a key objective of most AD therapies, and inhibition of angiotensin-converting enzyme (ACE) may delay onset or progression of AD. The effects of an ACE-inhibitor (ACE-I) and an angiotensin II receptor blocker (ARB) on Aβ and tau pathology in a triple transgenic (3xTGAD) mouse model of AD were investigated. 9-10month 3xTGAD mice were treated with ARB, ACE-I or vehicle for 6 months. Mean arterial blood pressure (MABP) was measured periodically and mice were assessed behaviourally. Aβ, phospho-tau, amyloid precursor protein (APP) and ACE activity were analysed. MABP was significantly reduced at 2 weeks and 3 months in the ACE-I group and at 3 months in the ARB group, compared to vehicle. Neither drug altered performance of 3xTGAD mice in Morris Water Maze or T-maze, nor were Aβ, tau immunolabelling or APP levels altered. ACE-I significantly reduced ACE activity in kidney. Prolonged treatment with ACE-I or ARB does not affect Aβ or phospho-tau accumulation in brains of aged 3xTGAD mice.
- Published
- 2012
47. Angiotensin II-inhibiting drugs have no effect on intraneuronal Aβ or oligomeric Aβ levels in a triple transgenic mouse model of Alzheimer's disease.
- Author
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Ferrington L, Miners JS, Palmer LE, Bond SM, Povey JE, Kelly PA, Love S, Horsburgh KJ, and Kehoe PG
- Abstract
Background: Reducing the excessive accumulation of amyloid β-protein (Aβ) in Alzheimer's disease (AD) is a key objective of most AD therapies. Several studies suggest that pharmacological inhibition of angiotensin-converting enzyme (ACE) or its by-product angiotensin II may delay onset or progression of dementia and it has been suggested that this occurs via regulation of Aβ. Intraneuronal oligomeric accumulation of Aβ is postulated to be one of the earliest pathological events. Thus this study investigated the effect of an ACE-inhibitor, captopril, and two angiotensin II receptor blockers (ARBs), eprosartan and valsartan, on intraneuronal Aβ pathology and oligomeric Aβ levels in a triple transgenic (3xTGAD) mouse model of AD., Methods: Male, adult (3-4 month old) 3xTgAD mice (n=39) were randomly assigned to 4 treatment groups: valsartan (0.17g/l), eprosartan (0.8g/l), captopril (5g/l) or normal drinking water and the drugs given ad libitum for 2 months. Mean arterial blood pressure (MABP) was measured at baseline, at 2 weeks and at 2 months when the mice were sacrificed and the brains hemisected for analysis. One hemisphere was processed for Aβ and amyloid precursor protein (APP) immunohistochemistry and the other for biochemical measurement of oligomeric Aβ and APP. ACE activity was measured in the brain and kidney., Results: MABP was significantly reduced at 2 weeks and 2 months in the ACE-I group (p=0.0006) but was unaltered in the ARB groups compared to vehicle. Neither ACE-I nor ARB treatment altered Aβ and APP immunolabelling or the level of Aβ or APP in brain tissue homogenates. Similarly neither ACE-I nor ARB treatment altered ACE activity in either brain or kidney compared to control tissue., Conclusions: ACE-I or ARB administration over 2 months did not affect APP levels or either intraneuronal Aβ or oligomeric Aβ levels in 3xTGAD mice. While ARBs did not alter MABP, captopril did mediate reductions in MABP in the 3xTGAD mice which appeared to be independent of ACE activity. Further studies are needed to examine the effects of these drugs over a longer term and in older mice (i.e. when AD-like changes are more pronounced).
- Published
- 2011
48. EDAR: an efficient error detection and removal algorithm for next generation sequencing data.
- Author
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Zhao X, Palmer LE, Bolanos R, Mircean C, Fasulo D, and Wittenberg GM
- Subjects
- Genome, Sequence Alignment methods, Algorithms, Computational Biology methods, Sequence Analysis, DNA methods
- Abstract
Genomic sequencing techniques introduce experimental errors into reads which can mislead sequence assembly efforts and complicate the diagnostic process. Here we present a method for detecting and removing sequencing errors from reads generated in genomic shotgun sequencing projects prior to sequence assembly. For each input read, the set of all length k substrings (k-mers) it contains are calculated. The read is evaluated based on the frequency with which each k-mer occurs in the complete data set (k-count). For each read, k-mers are clustered using the variable-bandwidth mean-shift algorithm. Based on the k-count of the cluster center, clusters are classified as error regions or non-error regions. For the 23 real and simulated data sets tested (454 and Solexa), our algorithm detected error regions that cover 99% of all errors. A heuristic algorithm is then applied to detect the location of errors in each putative error region. A read is corrected by removing the errors, thereby creating two or more smaller, error-free read fragments. After performing error removal, the error-rate for all data sets tested decreased (∼35-fold reduction, on average). EDAR has comparable accuracy to methods that correct rather than remove errors and when the error rate is greater than 3% for simulated data sets, it performs better. The performance of the Velvet assembler is generally better with error-removed data. However, for short reads, splitting at the location of errors can be problematic. Following error detection with error correction, rather than removal, may improve the assembly results.
- Published
- 2010
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49. Global gene expression profiling of Yersinia pestis replicating inside macrophages reveals the roles of a putative stress-induced operon in regulating type III secretion and intracellular cell division.
- Author
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Fukuto HS, Svetlanov A, Palmer LE, Karzai AW, and Bliska JB
- Subjects
- Animals, Bacterial Proteins metabolism, Cell Division, Cell Line, Citric Acid Cycle, Female, Mice, Mice, Inbred BALB C, Virulence, Yersinia pestis pathogenicity, Gene Expression Profiling, Macrophages microbiology, Operon physiology, Stress, Physiological genetics, Yersinia pestis genetics
- Abstract
Yersinia pestis, the causative agent of plague, is a facultative intracellular pathogen. Previous studies have indicated that the ability of Y. pestis to survive inside macrophages may be critical during the early stages of plague pathogenesis. To gain insights into the biology of intracellular Y. pestis and its environment following phagocytosis, we determined the genome-wide transcriptional profile of Y. pestis KIM5 replicating inside J774.1 macrophage-like cells using DNA microarrays. At 1.5, 4, and 8 h postinfection, a total of 801, 464, and 416 Y. pestis genes were differentially regulated, respectively, compared to the level of gene expression of control bacteria grown in tissue culture medium. A number of stress-response genes, including those involved in detoxification of reactive oxygen species, as well as several metabolic genes involved in macromolecule synthesis, were significantly induced in intracellular Y. pestis, consistent with the presence of oxidative stress and nutrient starvation inside Yersinia-containing vacuoles. A putative stress-induced operon consisting of y2313, y2315, and y2316 (y2313-y2316), and a previously unidentified open reading frame, orfX, was studied further on the basis of its high level of intracellular expression. Mutant strains harboring either deletion, Deltay2313-y2316 or DeltaorfX, exhibited diverse phenotypes, including reduced effector secretion by the type III secretion system, increased intracellular replication, and filamentous morphology of the bacteria growing inside macrophages. The results suggest a possible role for these genes in regulating cell envelope characteristics in the intracellular environment.
- Published
- 2010
- Full Text
- View/download PDF
50. Improving de novo sequence assembly using machine learning and comparative genomics for overlap correction.
- Author
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Palmer LE, Dejori M, Bolanos R, and Fasulo D
- Subjects
- Base Sequence, Databases, Nucleic Acid, Genome, Bacterial, Genome, Fungal, Artificial Intelligence, Genomics methods, Sequence Analysis, DNA methods
- Abstract
Background: With the rapid expansion of DNA sequencing databases, it is now feasible to identify relevant information from prior sequencing projects and completed genomes and apply it to de novo sequencing of new organisms. As an example, this paper demonstrates how such extra information can be used to improve de novo assemblies by augmenting the overlapping step. Finding all pairs of overlapping reads is a key task in many genome assemblers, and to this end, highly efficient algorithms have been developed to find alignments in large collections of sequences. It is well known that due to repeated sequences, many aligned pairs of reads nevertheless do not overlap. But no overlapping algorithm to date takes a rigorous approach to separating aligned but non-overlapping read pairs from true overlaps., Results: We present an approach that extends the Minimus assembler by a data driven step to classify overlaps as true or false prior to contig construction. We trained several different classification models within the Weka framework using various statistics derived from overlaps of reads available from prior sequencing projects. These statistics included percent mismatch and k-mer frequencies within the overlaps as well as a comparative genomics score derived from mapping reads to multiple reference genomes. We show that in real whole-genome sequencing data from the E. coli and S. aureus genomes, by providing a curated set of overlaps to the contigging phase of the assembler, we nearly doubled the median contig length (N50) without sacrificing coverage of the genome or increasing the number of mis-assemblies., Conclusions: Machine learning methods that use comparative and non-comparative features to classify overlaps as true or false can be used to improve the quality of a sequence assembly.
- Published
- 2010
- Full Text
- View/download PDF
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