23 results on '"Stewart DM"'
Search Results
2. Effects of sea-level rise on physiological ecology of populations of a ground-dwelling ant.
- Author
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Hooper-Bùi LM, Strecker-Lau RM, Stewart DM, Landry MJ, Papillion AM, Peterson SN, and Daniel RA
- Subjects
- Animals, Arthropod Venoms metabolism, Behavior, Animal, Ecosystem, Adaptation, Physiological, Ants physiology, Sea Level Rise
- Abstract
Introduction: Sea-level rise is a consequence of climate change that can impact the ecological and physiological changes of coastal, ground-dwelling species. Sea-level rise has a potential to inundate birds, rodents, spiders, and insects that live on the ground in coastal areas. Yet, there is still much to be learned concerning the specifics of these impacts. The red imported fire ant Solenopsis invicta (Buren) excavates soil for its home and is capable of surviving flooding. Because of their ground-dwelling life history and rapid reproduction, fire ants make an ideal model for discovery and prediction of changes that may be due to sea-level rise. There are up to 500,000 individuals in a colony, and these invasive ants naturally have a painful sting. However, observations suggest that colonies of fire ants that dwell in tidally-influenced areas are more aggressive with more frequent stings and more venom injected per sting (behavioral and physiological changes) than those located inland. This may be an adaption to sea-level rise. Therefore, the objective of this study is to elucidate differences in inland and coastal defensiveness via micro-dissection and comparison of head width, head length, stinger length, and venom sac volume. But first because fire ants' ability to raft on brackish tidal water is unknown, it had to be determined if fire ants could indeed raft in brackish water and examine the behavior differences between those flooded with freshwater vs. saltwater., Methods: To test the coastal-aggression hypothesis, inland colonies and coastal colonies, which experience relatively greater amounts of flooding, specifically regular tidal and windblown water and oscillations (i.e. El Nińo Southern Oscillation) from the Gulf of Mexico, were collected. To mimic sea-level rise, the colonies were flooded in salinities that correspond to both their collection site and conditions found in a variety of locales and situations (such as storm surge from a tropical storm). Individual ants were immediately taken from each colony for dissection before flooding, 1-hour into flooding, and 24-hours into flooding., Results and Discussion: Fire ants use their venom to defend themselves and to communicate alarm or aggression. Dissections and measurement of heads, venom sacs, and stingers revealed both coastal and inland colonies experience an increase in venom sac volume after 24 hours; in fact coastal colonies increased their venom volume by 75% after 24 h of flooding Whether this venom sac enlargement is due to diffusion of water or venom sac production is unknown. These ground-dwelling ants exhibit physiological and behavioral adaptations to ongoing sea-level rise possibly indicating that they are responding to increased flooding. Fire ants will raft on high-salinity water; and sea-level rise may cause stings by flooded ants to be more severe because of increased venom volume., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2020
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3. Spontaneous regression of primary cutaneous diffuse large B-cell lymphoma, leg type with significant T-cell immune response.
- Author
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Graham PM, Richardson AS, Schapiro BL, Saunders MD, and Stewart DM
- Abstract
We report a case of histologically confirmed primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) that subsequently underwent spontaneous regression in the absence of systemic treatment. The case showed an atypical lymphoid infiltrate that was CD20
+ and MUM-1+ and CD10- . A subsequent biopsy of the spontaneously regressed lesion showed fibrosis associated with a lymphocytic infiltrate comprising reactive T cells. PCDLBCL-LT is a cutaneous B-cell lymphoma with a poor prognosis, which is usually treated with chemotherapy. We describe a case of clinical and histologic spontaneous regression in a patient with PCDLBCL-LT who had a negative systemic workup but a recurrence over a year after his initial presentation.- Published
- 2018
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4. Inhibition of Receptor-Interacting Protein Kinase 1 with Necrostatin-1s ameliorates disease progression in elastase-induced mouse abdominal aortic aneurysm model.
- Author
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Wang Q, Zhou T, Liu Z, Ren J, Phan N, Gupta K, Stewart DM, Morgan S, Assa C, Kent KC, and Liu B
- Subjects
- Animals, Aortic Aneurysm, Abdominal chemically induced, Aortic Aneurysm, Abdominal genetics, Aortic Aneurysm, Abdominal pathology, Apoptosis drug effects, Cell Movement drug effects, Disease Models, Animal, Elastin agonists, Elastin genetics, Elastin metabolism, GTPase-Activating Proteins genetics, GTPase-Activating Proteins metabolism, Gene Expression Regulation, Humans, Injections, Intraperitoneal, Macrophages drug effects, Macrophages metabolism, Macrophages pathology, Male, Matrix Metalloproteinase 9 genetics, Matrix Metalloproteinase 9 metabolism, Mice, Mice, Inbred C57BL, Myocytes, Smooth Muscle drug effects, Myocytes, Smooth Muscle metabolism, Myocytes, Smooth Muscle pathology, Necrosis chemically induced, Necrosis genetics, Necrosis pathology, Pancreatic Elastase administration & dosage, Protein-Lysine 6-Oxidase genetics, Protein-Lysine 6-Oxidase metabolism, Tropoelastin agonists, Tropoelastin genetics, Tropoelastin metabolism, Anti-Inflammatory Agents pharmacology, Aortic Aneurysm, Abdominal drug therapy, Cardiovascular Agents pharmacology, GTPase-Activating Proteins antagonists & inhibitors, Imidazoles pharmacology, Indoles pharmacology, Necrosis prevention & control
- Abstract
Abdominal aortic aneurysm (AAA) is a common aortic disease with a progressive nature. There is no approved pharmacological treatment to effectively slow aneurysm growth or prevent rupture. Necroptosis is a form of programmed necrosis that is regulated by receptor-interacting protein kinases (RIPs). We have recently demonstrated that the lack of RIP3 in mice prevented aneurysm formation. The goal of the current study is to test whether perturbing necroptosis affects progression of existing aneurysm using the RIP1 inhibitors Necrostatin-1 (Nec-1) and an optimized form of Nec-1, 7-Cl-O-Nec-1 (Nec-1s). Seven days after aneurysm induction by elastase perfusion, mice were randomly administered DMSO, Nec-1 (3.2 mg/kg/day) and Nec-1s (1.6 mg/kg/day) via intraperitoneal injection. Upon sacrifice on day 14 postaneurysm induction, the aortic expansion in the Nec-1s group (64.12 ± 4.80%) was significantly smaller than that of the DMSO group (172.80 ± 13.68%) (P < 0.05). The mean aortic diameter of Nec-1 treated mice appeared to be smaller (121.60 ± 10.40%) than the DMSO group, though the difference was not statistically significant (P = 0.1). Histologically, the aortic structure of Nec-1s-treated mice appeared normal, with continuous and organized elastin laminae and abundant αActin-expressing SMCs. Moreover, Nect-1s treatment diminished macrophage infiltration and MMP9 accumulation and increased aortic levels of tropoelastin and lysyl oxidase. Together, our data suggest that pharmacological inhibition of necroptosis with Nec-1s stabilizes pre-existing aneurysms by diminishing inflammation and promoting connective tissue repair., Competing Interests: The authors declare no competing financial interests.
- Published
- 2017
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5. 90Y-daclizumab, an anti-CD25 monoclonal antibody, provided responses in 50% of patients with relapsed Hodgkin's lymphoma.
- Author
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Janik JE, Morris JC, O'Mahony D, Pittaluga S, Jaffe ES, Redon CE, Bonner WM, Brechbiel MW, Paik CH, Whatley M, Chen C, Lee JH, Fleisher TA, Brown M, White JD, Stewart DM, Fioravanti S, Lee CC, Goldman CK, Bryant BR, Junghans RP, Carrasquillo JA, Worthy T, Corcoran E, Conlon KC, and Waldmann TA
- Subjects
- Adult, Aged, Antibodies, Monoclonal, Humanized chemistry, Antibodies, Monoclonal, Humanized immunology, Daclizumab, Female, Hodgkin Disease immunology, Humans, Immunoglobulin G chemistry, Immunoglobulin G immunology, Male, Middle Aged, Phosphorylation, Recurrence, Young Adult, Antibodies, Monoclonal, Humanized therapeutic use, Hodgkin Disease drug therapy, Immunoglobulin G therapeutic use, Interleukin-2 Receptor alpha Subunit immunology, Yttrium Radioisotopes chemistry
- Abstract
Despite significant advances in the treatment of Hodgkin's lymphoma (HL), a significant proportion of patients will not respond or will subsequently relapse. We identified CD25, the IL-2 receptor alpha subunit, as a favorable target for systemic radioimmunotherapy of HL. The scientific basis for the clinical trial was that, although most normal cells with exception of Treg cells do not express CD25, it is expressed by a minority of Reed-Sternberg cells and by most polyclonal T cells rosetting around Reed-Sternberg cells. Forty-six patients with refractory and relapsed HL were evaluated with up to seven i.v. infusions of the radiolabeled anti-CD25 antibody (90)Y-daclizumab. (90)Y provides strong β emissions that kill tumor cells at a distance by a crossfire effect. In 46 evaluable HL patients treated with (90)Y-daclizumab there were 14 complete responses and nine partial responses; 14 patients had stable disease, and nine progressed. Responses were observed both in patients whose Reed-Sternberg cells expressed CD25 and in those whose neoplastic cells were CD25(-) provided that associated rosetting T cells expressed CD25. As assessed using phosphorylated H2AX (γ-H2AX) as a bioindicator of the effects of radiation exposure, predominantly nonmalignant cells in the tumor microenvironment manifested DNA damage, as reflected by increased expression of γ-H2AX. Toxicities were transient bone-marrow suppression and myelodysplastic syndrome in six patients who had not been evaluated with bone-marrow karyotype analyses before therapy. In conclusion, repeated (90)Y-daclizumab infusions directed predominantly toward nonmalignant T cells rosetting around Reed-Sternberg cells provided meaningful therapy for select HL patients.
- Published
- 2015
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6. Phase 1 trial of IL-15 trans presentation blockade using humanized Mikβ1 mAb in patients with T-cell large granular lymphocytic leukemia.
- Author
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Waldmann TA, Conlon KC, Stewart DM, Worthy TA, Janik JE, Fleisher TA, Albert PS, Figg WD, Spencer SD, Raffeld M, Decker JR, Goldman CK, Bryant BR, Petrus MN, Creekmore SP, and Morris JC
- Subjects
- Aged, Aged, 80 and over, Animals, Antibodies, Monoclonal adverse effects, Antibodies, Monoclonal immunology, Antibodies, Monoclonal, Humanized adverse effects, Antibodies, Monoclonal, Humanized immunology, Cell Division immunology, Cell Line, Tumor, Female, Humans, Injections, Intravenous, Interleukin Receptor Common gamma Subunit immunology, Interleukin-15 genetics, Interleukin-15 immunology, Interleukin-2 Receptor beta Subunit genetics, Macaca fascicularis, Male, Mice, Middle Aged, RNA, Messenger metabolism, Treatment Outcome, Antibodies, Monoclonal administration & dosage, Antibodies, Monoclonal, Humanized administration & dosage, Interleukin-2 Receptor beta Subunit immunology, Leukemia, Large Granular Lymphocytic immunology, Leukemia, Large Granular Lymphocytic therapy
- Abstract
In the present study, Hu-Mikβ1, a humanized mAb directed at the shared IL-2/IL-15Rβ subunit (CD122) was evaluated in patients with T-cell large granular lymphocytic (T-LGL) leukemia. Hu-Mikβ1 blocked the trans presentation of IL-15 to T cells expressing IL-2/IL-15Rβ and the common γ-chain (CD132), but did not block IL-15 action in cells that expressed the heterotrimeric IL-15 receptor in cis. There was no significant toxicity associated with Hu-Mikβ1 administration in patients with T-LGL leukemia, but no major clinical responses were observed. One patient who had previously received murine Mikβ1 developed a measurable Ab response to the infused Ab. Nevertheless, the safety profile of this first in-human study of the humanized mAb to IL-2/IL-15Rβ (CD122) supports its evaluation in disorders such as refractory celiac disease, in which IL-15 and its receptor have been proposed to play a critical role in the pathogenesis and maintenance of disease activity.
- Published
- 2013
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7. Radiation therapy for the management of patients with HTLV-1-associated adult T-cell leukemia/lymphoma.
- Author
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Simone CB 2nd, Morris JC, Stewart DM, Urquhart NE, Janik JE, Kreitman RJ, Lita E, Conlon K, Wharfe G, Waldmann TA, and Kaushal A
- Subjects
- Adult, Aged, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Combined Modality Therapy, Female, HTLV-I Infections virology, Humans, Leukemia-Lymphoma, Adult T-Cell complications, Leukemia-Lymphoma, Adult T-Cell drug therapy, Male, Middle Aged, Mucositis etiology, Radiotherapy adverse effects, Radiotherapy Dosage, Retrospective Studies, Skin Diseases etiology, Survival Analysis, Treatment Outcome, HTLV-I Infections complications, Human T-lymphotropic virus 1, Leukemia-Lymphoma, Adult T-Cell radiotherapy, Radiotherapy methods
- Abstract
Human T-cell leukemia virus type 1-associated adult T-cell leukemia/lymphoma (ATL) typically has survivals measured in months with chemotherapy. One prior published series (1983-1991) assessed local radiotherapy for ATL. Ten consecutive patients with pathologically confirmed ATL treated with radiotherapy were reviewed. Subtypes included acute (n = 7), smoldering (n = 2), and lymphomatous (n = 1). Patients received an average of 2.5 systemic therapy regimens before radiotherapy. Twenty lesions (cutaneous = 10, nodal = 8, extranodal = 2) were treated to a mean of 35.4 Gy/2-3 Gy (range, 12-60 Gy). At 9.0-month mean follow-up (range, 0.1-42.0 months), all lesions symptomatically and radiographically responded, with in-field complete responses in 40.0% (nodal 37.5% vs. cutaneous 50.0%; P = .62). No patient experienced in-field progression. Nine patients developed new/progressive out-of-field disease. Median survival was 17.0 months (3-year survival, 30.0%). No Radiation Therapy Oncology Group acute grade ≥ 3 or any late toxicity was noted. This report is the first to use modern radiotherapy techniques and finds effective local control across ATL subtypes. Radiotherapy should be considered for symptomatic local progression of ATL.
- Published
- 2012
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8. AOF1 is a histone H3K4 demethylase possessing demethylase activity-independent repression function.
- Author
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Yang Z, Jiang J, Stewart MD, Qi S, Yamane K, Li J, Zhang Y, and Wong J
- Subjects
- Animals, Chromosomes metabolism, Histone Deacetylases metabolism, Histones metabolism, Mice, Mitosis, Oocytes metabolism, Oxidoreductases, N-Demethylating genetics, Protein Structure, Tertiary, Repressor Proteins genetics, Transcription, Genetic, Xenopus, Zinc Fingers, Oxidoreductases, N-Demethylating metabolism, Repressor Proteins metabolism
- Abstract
LSD1 (KDM1 under the new nomenclature) was the first identified lysine-specific histone demethylase belonging to the flavin-dependent amine oxidase family. Here, we report that AOF1 (KDM1B under the new nomenclature), a mammalian protein related to LSD1, also possesses histone demethylase activity with specificity for H3K4me1 and H3K4me2. Like LSD1, the highly conserved SWIRM domain is required for its enzymatic activity. However, AOF1 differs from LSD1 in several aspects. First, AOF1 does not appear to form stable protein complexes containing histone deacetylases. Second, AOF1 is found to localize to chromosomes during the mitotic phase of the cell cycle, whereas LSD1 does not. Third, AOF1 represses transcription when tethered to DNA and this repression activity is independent of its demethylase activity. Structural and functional analyses identified its unique N-terminal Zf-CW domain as essential for the demethylase activity-independent repression function. Collectively, our study identifies AOF1 as the second histone demethylase in the family of flavin-dependent amine oxidases and reveals a demethylase-independent repression function of AOF1.
- Published
- 2010
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9. Building community and public health nursing capacity: a synthesis report of the National Community Health Nursing Study.
- Author
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Underwood JM, Mowat DL, Meagher-Stewart DM, Deber RB, Baumann AO, MacDonald MB, Akhtar-Danesh N, Schoenfeld BM, Ciliska DK, Blythe JM, Lavoie-Tremblay M, Ehrlich AS, Knibbs KM, and Munroe VJ
- Subjects
- Adult, Aged, Canada, Career Mobility, Female, Focus Groups, Health Care Surveys, Health Policy, Humans, Job Satisfaction, Male, Middle Aged, Psychometrics, Public Health standards, Public Health Practice, Qualitative Research, Surveys and Questionnaires, Workforce, Community Health Nursing standards, Community Health Nursing statistics & numerical data, Nurses psychology, Public Health Administration standards, Public Health Nursing standards, Public Health Nursing statistics & numerical data
- Abstract
Objectives: 1) To describe the community health nursing workforce in Canada; 2) To compare, across political jurisdictions and community health sectors, what helps and hinders community nurses to work effectively; 3) To identify organizational attributes that support one community subsector--public health nurses--to practise the full scope of their competencies., Methods: Our study included an analysis of the Canadian Institute for Health Information nursing databases (1996-2007), a survey of over 13,000 community health nurses across Canada and 23 focus groups of public health policy-makers and front-line public health nurses., Results: Over 53,000 registered and licensed practical nurses worked in community health in Canada in 2007, about 16% of the nursing workforce. Community nurses were older on average than the rest of their profession. Typical practice settings for community nurses included community health centres, home care and public health units/departments. To practise effectively, community nurses need professional confidence, good team relationships, supportive workplaces and community support. Most community nurses felt confident in their practice and relationships with other nurses and professionals, though less often with physicians. Their feelings about salary and job security were mixed, and most community nurses would like more learning opportunities, policy and practice information and chances to debrief about work. They needed their communities to do more to address social determinants of health and provide good quality resources. Public health nursing needs a combination of factors to succeed: sound government policy, supportive organizational culture and good management practices. Organizational attributes identified as supports for optimal practice include: flexibility in funding, program design and job descriptions; clear organizational vision driven by shared values and community needs; coordinated public health planning across jurisdictions; and strong leadership that openly promotes public health, values their staff's work and invests in education and training., Conclusion: The interchangeable and inconsistent use of titles used by community nurses and their employers makes it difficult to discern differences within this sector such as home care, public health, etc. Our studies also revealed that community nurses: thrive in workplaces where they share the vision and goals of their organization and work collaboratively in an atmosphere that supports creative, autonomous practice; work well together, but need time, flexible funding and management support to develop relationships with the community and their clients, and to build teams with other professionals; could sustain their competencies and confidence in their professional abilities with more access to continuing education, policies, evidence and debriefing sessions.
- Published
- 2009
10. High-Throughput GoMiner, an 'industrial-strength' integrative gene ontology tool for interpretation of multiple-microarray experiments, with application to studies of Common Variable Immune Deficiency (CVID).
- Author
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Zeeberg BR, Qin H, Narasimhan S, Sunshine M, Cao H, Kane DW, Reimers M, Stephens RM, Bryant D, Burt SK, Elnekave E, Hari DM, Wynn TA, Cunningham-Rundles C, Stewart DM, Nelson D, and Weinstein JN
- Subjects
- Binding Sites, Chromosome Mapping, Cluster Analysis, Common Variable Immunodeficiency drug therapy, Data Display, Databases, Genetic, Electronic Data Processing, Humans, Phenotype, Schistosomiasis genetics, Software Design, Transcription Factors metabolism, Common Variable Immunodeficiency genetics, Gene Expression Profiling instrumentation, Protein Array Analysis instrumentation, Software, User-Computer Interface
- Abstract
Background: We previously developed GoMiner, an application that organizes lists of 'interesting' genes (for example, under-and overexpressed genes from a microarray experiment) for biological interpretation in the context of the Gene Ontology. The original version of GoMiner was oriented toward visualization and interpretation of the results from a single microarray (or other high-throughput experimental platform), using a graphical user interface. Although that version can be used to examine the results from a number of microarrays one at a time, that is a rather tedious task, and original GoMiner includes no apparatus for obtaining a global picture of results from an experiment that consists of multiple microarrays. We wanted to provide a computational resource that automates the analysis of multiple microarrays and then integrates the results across all of them in useful exportable output files and visualizations., Results: We now introduce a new tool, High-Throughput GoMiner, that has those capabilities and a number of others: It (i) efficiently performs the computationally-intensive task of automated batch processing of an arbitrary number of microarrays, (ii) produces a human-or computer-readable report that rank-orders the multiple microarray results according to the number of significant GO categories, (iii) integrates the multiple microarray results by providing organized, global clustered image map visualizations of the relationships of significant GO categories, (iv) provides a fast form of 'false discovery rate' multiple comparisons calculation, and (v) provides annotations and visualizations for relating transcription factor binding sites to genes and GO categories., Conclusion: High-Throughput GoMiner achieves the desired goal of providing a computational resource that automates the analysis of multiple microarrays and integrates results across all of the microarrays. For illustration, we show an application of this new tool to the interpretation of altered gene expression patterns in Common Variable Immune Deficiency (CVID). High-Throughput GoMiner will be useful in a wide range of applications, including the study of time-courses, evaluation of multiple drug treatments, comparison of multiple gene knock-outs or knock-downs, and screening of large numbers of chemical derivatives generated from a promising lead compound.
- Published
- 2005
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11. Mutations of the Wiskott-Aldrich Syndrome Protein (WASP): hotspots, effect on transcription, and translation and phenotype/genotype correlation.
- Author
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Jin Y, Mazza C, Christie JR, Giliani S, Fiorini M, Mella P, Gandellini F, Stewart DM, Zhu Q, Nelson DL, Notarangelo LD, and Ochs HD
- Subjects
- Child, Child, Preschool, Female, Genotype, Humans, Infant, Male, Phenotype, Sequence Deletion, Wiskott-Aldrich Syndrome Protein, Gene Expression Regulation, Mutation, Protein Biosynthesis genetics, Proteins genetics, Transcription, Genetic genetics, Wiskott-Aldrich Syndrome genetics
- Abstract
The Wiskott-Aldrich syndrome (WAS) is an X-linked recessive immune deficiency disorder characterized by thrombocytopenia, small platelet size, eczema, recurrent infections, and increased risk of autoimmune disorders and malignancies. X-linked thrombocytopenia (XLT) is an allelic variant of WAS which presents with a milder phenotype, generally limited to thrombocytopenia. WAS and XLT are caused by mutations of the Wiskott-Aldrich syndrome protein (WASP) gene which encodes a 502-amino acid protein, named WASP. WASP is thought to play a role in actin cytoskeleton organization and cell signaling. Here, we report the identification of 141 unique mutations, 71 not previously reported, from 227 WAS/XLT families with a total of 262 affected members. When possible we studied the effects of these mutations on transcription, RNA splicing, and protein expression. By analyzing a large number of patients with WAS/XLT at the molecular level we identified 5 mutational hotspots in the WASP gene and have been able to establish a strong association between genotype and phenotype.
- Published
- 2004
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12. AKAP350 interaction with cdc42 interacting protein 4 at the Golgi apparatus.
- Author
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Larocca MC, Shanks RA, Tian L, Nelson DL, Stewart DM, and Goldenring JR
- Subjects
- Adaptor Proteins, Signal Transducing chemistry, Adaptor Proteins, Signal Transducing genetics, Animals, Carrier Proteins genetics, Carrier Proteins metabolism, Cell Line, Colforsin pharmacology, Cyclic AMP-Dependent Protein Kinase Type II, Cyclic AMP-Dependent Protein Kinases antagonists & inhibitors, Cyclic AMP-Dependent Protein Kinases metabolism, Cytoskeletal Proteins chemistry, Cytoskeletal Proteins genetics, Dogs, Microtubule-Associated Proteins chemistry, Microtubule-Associated Proteins genetics, Phosphorylation drug effects, Protein Binding, Protein Structure, Tertiary, RNA Interference, Rabbits, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Transfection, Two-Hybrid System Techniques, Adaptor Proteins, Signal Transducing metabolism, Cytoskeletal Proteins metabolism, Golgi Apparatus metabolism, Microtubule-Associated Proteins metabolism
- Abstract
The A kinase anchoring protein 350 (AKAP350) is a multiply spliced type II protein kinase A anchoring protein that localizes to the centrosomes in most cells and to the Golgi apparatus in epithelial cells. In the present study, we sought to identify AKAP350 interacting proteins that could yield insights into AKAP350 function at the Golgi apparatus. Using yeast two-hybrid and pull-down assays, we found that AKAP350 interacts with a family of structurally related proteins, including FBP17, FBP17b, and cdc42 interacting protein 4 (CIP4). CIP4 interacts with the GTP-bound form of cdc42, with the Wiscott Aldrich Syndrome group of proteins, and with microtubules, and exerts regulatory effects on cytoskeleton and membrane trafficking. CIP4 is phosphorylated by protein kinase A in vitro, and elevation of intracellular cyclic AMP with forskolin stimulates in situ phosphorylation of CIP4. Our results indicate that CIP4 interacts with AKAP350 at the Golgi apparatus and that either disruption of this interaction by expressing the CIP4 binding domain in AKAP350, or reduction of AKAP350 expression by RNA interference leads to changes in Golgi structure. The results suggest that AKAP350 and CIP4 influence the maintenance of normal Golgi apparatus structure.
- Published
- 2004
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13. Altered gene expression pattern in cultured human breast cancer cells treated with hepatocyte growth factor/scatter factor in the setting of DNA damage.
- Author
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Yuan R, Fan S, Achary M, Stewart DM, Goldberg ID, and Rosen EM
- Subjects
- Antibiotics, Antineoplastic pharmacology, Breast Neoplasms metabolism, Doxorubicin pharmacology, Gene Expression Profiling, Humans, Microtubule-Associated Proteins physiology, Minor Histocompatibility Antigens, Oligonucleotide Array Sequence Analysis, RNA, Messenger biosynthesis, RNA, Messenger genetics, Reverse Transcriptase Polymerase Chain Reaction, Tumor Cells, Cultured drug effects, Breast Neoplasms genetics, DNA Damage physiology, Gene Expression Regulation, Neoplastic drug effects, Hepatocyte Growth Factor pharmacology
- Abstract
The cytokine hepatocyte growth factor/scatter factor (HGF/SF) protects epithelial and cancer cells against DNA-damaging agents via a pathway involving signaling from c-Met --> phosphatidylinositol-3- kinase --> c-Akt. However, the downstream alterations in gene expression resulting from this pathway have not been established. On the basis of cDNA microarray and semiquantitative RT-PCR assays, we found that MDA-MB-453 human breast cancer cells preincubated with HGF/SF and then exposed to Adriamycin (ADR), a DNA topoisomerase II inhibitor, exhibit an altered pattern of gene expression, as compared with cells treated with ADR only. [HGF/SF+ADR]-treated cells showed altered expression of genes involved in the DNA damage response, cell cycle regulation, signal transduction, metabolism, and development. Some of these alterations suggest mechanisms by which HGF/SF may exert its protective activity, e.g., up-regulation of polycystic kidney disease-1 (a survival-promoting component of cadherin-catenin complexes), down-regulation of 51C (an inositol polyphosphate-5-phosphatase), and down-regulation of TOPBP1 (a topoisomerase IIB binding protein). We showed that enforced expression of the cdc42-interacting protein CIP4, a cytoskeleton-associated protein for which expression was decreased in [HGF/SF+ADR]-treated cells, inhibited HGF/SF-mediated protection against ADR. The cDNA microarray approach may open up new avenues for investigation of the DNA damage response and its regulation by HGF/SF.
- Published
- 2001
14. A case of win, lose, draw.
- Author
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Stewart DM Jr
- Subjects
- Fees and Charges legislation & jurisprudence, Humans, Insurance, Liability economics, Louisiana, Rate Setting and Review legislation & jurisprudence, Insurance, Liability legislation & jurisprudence
- Published
- 2001
15. Interferon-tau activates multiple signal transducer and activator of transcription proteins and has complex effects on interferon-responsive gene transcription in ovine endometrial epithelial cells.
- Author
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Stewart MD, Johnson GA, Vyhlidal CA, Burghardt RC, Safe SH, Yu-Lee LY, Bazer FW, and Spencer TE
- Subjects
- Animals, Cell Nucleus metabolism, Cells, Cultured, Endometrium cytology, Epithelial Cells cytology, Female, Interferon Type I physiology, Interferon-Stimulated Gene Factor 3, Luciferases, Phosphorylation, Pregnancy Proteins physiology, Promoter Regions, Genetic, Protein Transport, Recombinant Fusion Proteins analysis, STAT1 Transcription Factor, STAT2 Transcription Factor, Sheep, Signal Transduction, Transcription Factors metabolism, Transcription, Genetic drug effects, Transfection, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Endometrium physiology, Epithelial Cells physiology, Interferon Type I pharmacology, Pregnancy Proteins pharmacology, Trans-Activators genetics, Trans-Activators metabolism, Transcription, Genetic physiology
- Abstract
Interferon-tau (IFNtau), a type I IFN produced by sheep conceptus trophectoderm, is the signal for maternal recognition of pregnancy. Although it is clear that IFNtau suppresses transcription of the estrogen receptor alpha and oxytocin receptor genes and induces expression of various IFN-stimulated genes within the endometrial epithelium, little is known of the signal transduction pathway activated by the hormone. This study determined the effects of IFNtau on signal transducer and activator of transcription (STAT) activation, expression, DNA binding, and transcriptional activation using an ovine endometrial epithelial cell line. IFNtau induced persistent tyrosine phosphorylation and nuclear translocation of STAT1 and -2 (10 min to 48 h), but transient phosphorylation and nuclear translocation of STAT3, -5a/b, and -6 (10 to <60 min). IFNtau increased expression of STAT1 and -2, but not STAT3, -5a/b, and -6. IFN-stimulated gene factor-3 and STAT1 homodimers formed and bound an IFN-stimulated response element (ISRE) and gamma-activated sequence (GAS) element, respectively. IFNtau increased transcription of GAS-driven promoters at 3 h, but suppressed their activity at 24 h. In contrast, the activity of an ISRE-driven promoter was increased at 3 and 24 h. These results indicate that IFNtau activates multiple STATs and has differential effects on ISRE- and GAS-driven gene transcription.
- Published
- 2001
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16. Cdc42-interacting protein 4 mediates binding of the Wiskott-Aldrich syndrome protein to microtubules.
- Author
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Tian L, Nelson DL, and Stewart DM
- Subjects
- Binding Sites, Fluorescent Antibody Technique, Humans, Microtubule-Associated Proteins genetics, Microtubule-Associated Proteins isolation & purification, Minor Histocompatibility Antigens, Precipitin Tests, Protein Binding, Proteins isolation & purification, Tubulin isolation & purification, Two-Hybrid System Techniques, Wiskott-Aldrich Syndrome Protein, cdc42 GTP-Binding Protein metabolism, src Homology Domains, Microtubule-Associated Proteins metabolism, Microtubules metabolism, Proteins metabolism, Wiskott-Aldrich Syndrome
- Abstract
The Wiskott-Aldrich syndrome is an inherited X-linked immunodeficiency characterized by thrombocytopenia, eczema, and a tendency toward lymphoid malignancy. Lymphocytes from affected individuals have cytoskeletal abnormalities, and monocytes show impaired motility. The Wiskott-Aldrich syndrome protein (WASP) is a multi-domain protein involved in cytoskeletal organization. In a two-hybrid screen, we identified the protein Cdc42-interacting protein 4 (CIP4) as a WASP interactor. CIP4, like WASP, is a Cdc42 effector protein involved in cytoskeletal organization. We found that the WASP-CIP4 interaction is mediated by the binding of the Src homology 3 domain of CIP4 to the proline-rich segment of WASP. Cdc42 was not required for this interaction. Co-expression of CIP4 and green fluorescent protein-WASP in COS-7 cells led to the association of WASP with microtubules. In vitro experiments showed that CIP4 binds to microtubules via its NH(2) terminus. The region of CIP4 responsible for binding to active Cdc42 was localized to amino acids 383-417, and the mutation I398S abrogated binding. Deletion of the Cdc42-binding domain of CIP4 did not affect the colocalization of WASP with microtubules in vivo. We conclude that CIP4 can mediate the association of WASP with microtubules. This may facilitate transport of WASP to sites of substrate adhesion in hematopoietic cells.
- Published
- 2000
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17. Retrovirus-mediated WASP gene transfer corrects defective actin polymerization in B cell lines from Wiskott-Aldrich syndrome patients carrying 'null' mutations.
- Author
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Candotti F, Facchetti F, Blanzuoli L, Stewart DM, Nelson DL, and Blaese RM
- Subjects
- B-Lymphocytes metabolism, Blotting, Western, Cell Line, Genetic Vectors, Humans, Actins metabolism, Genetic Therapy methods, Mutation genetics, Wiskott-Aldrich Syndrome genetics
- Abstract
Boys affected with Wiskott-Aldrich syndrome (WAS) present with variable association of thrombocytopenia, eczema and immune deficiency. If untreated, WAS patients may succumb to intracerebral hemorrhages, severe infections or malignancies. Allogeneic bone marrow transplantation (BMT) can cure all aspects of the disease, but HLA-identical donors are not available to all patients and mismatched BMTs are unfortunately associated with high mortality and morbidity. The good success of HLA-matched BMT, however, makes WAS a potential candidate for hematopoietic stem cell gene therapy. WAS patients carry mutations of the Wiskott-Aldrich syndrome protein gene encoding WASP, a 502-amino acid proline-rich protein with demonstrated involvement in the organization of the actin cytoskeleton. To verify the feasibility of genetic correction for this disease, the WASP cDNA was expressed in EBV-immortalized B cell lines obtained from WAS patients using a retroviral vector. Transduced WAS cells showed levels of WASP expression similar to those found in cells from normal donors, without detectable effects on viability or growth characteristics. In addition, retrovirus-mediated expression of WASP led to improvement of cytoplasmic F-actin expression and formation of F-actin-positive microvilli, a process shown to be defective in untransduced WAS cell lines. These preliminary results indicate a potential use for retrovirus-mediated gene transfer as therapy for WAS.
- Published
- 1999
- Full Text
- View/download PDF
18. Identification of regions of the Wiskott-Aldrich syndrome protein responsible for association with selected Src homology 3 domains.
- Author
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Finan PM, Soames CJ, Wilson L, Nelson DL, Stewart DM, Truong O, Hsuan JJ, and Kellie S
- Subjects
- Amino Acid Sequence, Binding Sites, Humans, Molecular Sequence Data, Molecular Weight, Proteins chemistry, Proteins genetics, Proto-Oncogene Proteins metabolism, Sequence Alignment, Structure-Activity Relationship, Type C Phospholipases metabolism, Wiskott-Aldrich Syndrome genetics, Wiskott-Aldrich Syndrome Protein, src-Family Kinases, Proteins metabolism, Wiskott-Aldrich Syndrome metabolism, src Homology Domains
- Abstract
Src homology 3 (SH3) domains have been shown to mediate selected interactions between signaling molecules and are essential for the activation of a number of receptor-driven pathways. The Wiskott-Aldrich syndrome protein was identified as a protein that associated selectively with the SH3 domains derived from c-Src, p85alpha, phospholipase Cgamma1, and c-Fgr. Significantly reduced association was detected to the N-terminal SH3 domain and the tandem SH3 domains of p47(phox), and no binding was detected to the SH3 domain of n-Src, the C-terminal SH3 domain of p47(phox), or either of the SH3 domains of p67(phox). Three peptides corresponding to potential Wiskott-Aldrich syndrome protein SH3 domain binding motifs were found to inhibit its association with c-Src, Fgr, and phospholipase Cgamma1 SH3 domains, but not the p85alpha SH3 domain. These peptides have the sequences MRRQEPLPPPPPPSRG, TGRSGPLPPPPPGA, and KGRSGPLPPVPLGI and show homology with other SH3 domain binding motifs. It is possible that the intracellular association of Wiskott-Aldrich syndrome protein with other signaling proteins is mediated by its SH3 domain-binding regions, and this may play a role in its putative function as a regulatory molecule in immune cells.
- Published
- 1996
- Full Text
- View/download PDF
19. Studies of the expression of the Wiskott-Aldrich syndrome protein.
- Author
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Stewart DM, Treiber-Held S, Kurman CC, Facchetti F, Notarangelo LD, and Nelson DL
- Subjects
- Amino Acid Sequence, Animals, Antibodies, Monoclonal, B-Lymphocytes, Base Sequence, Blood Platelets metabolism, Blotting, Western, Cell Line, Cell Line, Transformed, Child, Preschool, Cloning, Molecular, DNA Primers, DNA, Complementary, Humans, Infant, Mice, Molecular Sequence Data, Monocytes metabolism, Oligopeptides, Peptide Biosynthesis, Polymerase Chain Reaction, Proteins analysis, Proteins genetics, Recombinant Fusion Proteins biosynthesis, Reference Values, T-Lymphocytes metabolism, Wiskott-Aldrich Syndrome genetics, Wiskott-Aldrich Syndrome Protein, Mutation, Peptides, Protein Biosynthesis, Wiskott-Aldrich Syndrome metabolism
- Abstract
The Wiskott-Aldrich syndrome (WAS) is an X-linked disorder characterized by thrombocytopenia, eczema, disorders in cell-mediated and humoral immunity, and a proclivity to lymphoproliferative disease. The gene responsible encodes a 53-kD proline-rich protein of unknown function (WASP). We produced a FLAG-WASP fusion protein that was used to immunize mice and produce mAbs against WASP. Using monoclonal anti-WASP in Western immunoblots, we have determined that WASP is present in the cytoplasmic but not nuclear fraction of normal human peripheral blood mononuclear cells, in normal human platelets, in T lymphocytes, non-T lymphocytes, and monocytes. The protein is produced in the B cell immunoblastic cell line DS-1, in normal EBV-transformed B cell lines, and in HEL92.1.7, but is barely detectable in MOLT-4 and not detectable in K562. WASP was present in two of four EBV-transformed cell lines from WAS patients. Splenic tissue immunostaining was performed in two patients, and the results correlated with the results of the Western blots. Sequence analysis of WASP cDNA from two patients who produce WASP show mutations causing amino acid substitutions. These studies establish a foundation for further studies aimed at understanding the function of WASP.
- Published
- 1996
- Full Text
- View/download PDF
20. Acupuncture analgesia.
- Author
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Stewart DM
- Subjects
- Humans, Acupuncture Therapy methods, Analgesia
- Published
- 1977
- Full Text
- View/download PDF
21. EFFECT OF LOCAL ANESTHETICS ON THE CARDIOVASCULAR SYSTEM OF THE DOG.
- Author
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STEWART DM, ROGERS WP, MAHAFFEY JE, WITHERSPOON S, and WOODS EF
- Subjects
- Dogs, Anesthetics, Anesthetics, Local, Cardiovascular System, Cocaine, Heart, Lidocaine, Pharmacology, Procaine, Research, Tetracaine
- Published
- 1963
- Full Text
- View/download PDF
22. URINE FORMATION IN A PULMONATE LAND SNAIL, ACHATINA FULICA.
- Author
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MARTIN AW, STEWART DM, and HARRISON FM
- Subjects
- Animals, Absorption, Blood Glucose, Body Fluids, Chemical Phenomena, Chemistry, Chlorides, Diuresis, Fluids and Secretions, Helix, Snails, Indicators and Reagents, Inulin, Metabolism, Pharmacology, Phlorhizin, Pressure, Research, Snails, Urea, Urine, p-Aminohippuric Acid
- Published
- 1965
- Full Text
- View/download PDF
23. Changes in the protein composition of muscles of the rat in hypertrophy and atrophy.
- Author
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STEWART DM
- Subjects
- Animals, Rats, Atrophy, Hyperplasia, Hypertrophy, Muscle Proteins, Muscles, Proteins metabolism
- Published
- 1955
- Full Text
- View/download PDF
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