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Lee H, Culpepper J, Porter E. Analysis of electrode arrangements for brain stroke diagnosis via electrical impedance tomography through numerical computational models. Physiol Meas 2024; 45:025006. [PMID: 38306666 DOI: 10.1088/1361-6579/ad252c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/02/2024] [Indexed: 02/04/2024]
Abstract
Objective.Rapid stroke-type classification is crucial for improved prognosis. However, current methods for classification are time-consuming, require expensive equipment, and can only be used in the hospital. One method that has demonstrated promise in a rapid, low-cost, non-invasive approach to stroke diagnosis is electrical impedance tomography (EIT). While EIT for stroke diagnosis has been the topic of several studies in recent years, to date, the impact of electrode placements and arrangements has rarely been analyzed or tested and only in limited scenarios. Optimizing the location and choice of electrodes can have the potential to improve performance and reduce hardware cost and complexity and, most importantly, diagnosis time.Approach.In this study, we analyzed the impact of electrodes in realistic numerical models by (1) investigating the effect of individual electrodes on the resulting simulated EIT boundary measurements and (2) testing the performance of different electrode arrangements using a machine learning classification model.Main results.We found that, as expected, the electrodes deemed most significant in detecting stroke depend on the location of the electrode relative to the stroke lesion, as well as the role of the electrode. Despite this dependence, there are notable electrodes used in the models that are consistently considered to be the most significant across the various stroke lesion locations and various head models. Moreover, we demonstrate that a reduction in the number of electrodes used for the EIT measurements is possible, given that the electrodes are approximately evenly distributed.Significance.In this way, electrode arrangement and location are important variables to consider when improving stroke diagnosis methods using EIT.
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Affiliation(s)
- Hannah Lee
- Chandra Family Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas, United States of America
| | - Jared Culpepper
- Chandra Family Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas, United States of America
| | - Emily Porter
- Chandra Family Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas, United States of America
- Department of Biomedical Engineering, McGill University, Montreal, Canada
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2
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Culpepper J, Lee H, Santorelli A, Porter E. Applied machine learning for stroke differentiation by electrical impedance tomography with realistic numerical models. Biomed Phys Eng Express 2023; 10:015012. [PMID: 37939489 DOI: 10.1088/2057-1976/ad0adf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 11/08/2023] [Indexed: 11/10/2023]
Abstract
Electrical impedance tomography (EIT) may have potential to overcome existing limitations in stroke differentiation, enabling low-cost, rapid, and mobile data collection. Combining bioimpedance measurement technologies such as EIT with machine learning classifiers to support decision-making can avoid commonly faced reconstruction challenges due to the nonlinear and ill-posed nature of EIT imaging. Therefore, in this work, we advance this field through a study integrating realistic head models with clinically relevant test scenarios, and a robust architecture consisting of nested cross-validation and principal component analysis. Specifically, realistic head models are designed which incorporate the highly conductive layers of cerebrospinal fluid in the subarachnoid space and ventricles. In total, 135 unique models are created to represent a large patient population, with normal, haemorrhagic, and ischemic brains. Simulated EIT voltage data generated from these models are used to assess the classification performance of support vector machines. Parameters explored include driving frequency, signal-to-noise ratio, kernel function, and composition of binary classes. Classifier accuracy at 60 dB signal-to-noise ratio, reported as mean and standard deviation, are (79.92% ± 10.82%) for lesion differentiation, (74.78% ± 3.79%) for lesion detection, (77.49% ± 15.90%) for bleed detection, and (60.31% ± 3.98%) for ischemia detection (after ruling out bleed). The results for each method were obtained with statistics from 3 independent runs with 17,280 observations, polynomial kernel functions, and feature reduction of 76% by PCA (from 208 to 50 features). While results of this study show promise for stroke differentiation using EIT data, our findings indicate that the achievable accuracy is highly dependent on the classification scenario and application-specific classifiers may be necessary to achieve acceptable accuracy.
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Affiliation(s)
| | - Hannah Lee
- University of Texas at Austin, United States of America
| | | | - Emily Porter
- University of Texas at Austin, United States of America
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3
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Lee H, Culpepper J, Farshkaran A, McDermott B, Porter E. Impact of Local Electrodes on Brain Stroke Type Differentiation using Electrical Impedance Tomography. Annu Int Conf IEEE Eng Med Biol Soc 2021; 2021:1412-1415. [PMID: 34891549 DOI: 10.1109/embc46164.2021.9629682] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Electrical impedance tomography (EIT) of the head has the potential to provide rapid characterization of brain stroke. This study builds on previous work by implementing a more anatomically complex head model, contrasting results of bleed and clot simulations, and by establishing the electrodes which dominate in voltage difference measurements. This work provides the basis for machine learning with clusters of small numbers of electrodes as unique features for stroke-type detection and differentiation.Clinical Relevance- This application of EIT can aid in early detection, classification, and localization of brain stroke, allowing for faster treatment.
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4
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Royal W, Lee-Wilk T, Wallin M, Bever C, Kane R, Maloni H, Finkelstein J, Cha E, McCarthy M, Levin M, Tyor W, Culpepper J, Mitchell L, Zhan M. CXCR3+ Naive T Helper Cell Percentages Correlate with Neuropsychological Test Abnormalities in Patients with MS (P04.102). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p04.102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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5
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Pan Y, Lloyd C, Zhou H, Dolich S, Deeds J, Gonzalo JA, Vath J, Gosselin M, Ma J, Dussault B, Woolf E, Alperin G, Culpepper J, Gutierrez-Ramos JC, Gearing D. Neurotactin, a membrane-anchored chemokine upregulated in brain inflammation. Nature 1997; 387:611-7. [PMID: 9177350 DOI: 10.1038/42491] [Citation(s) in RCA: 461] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Chemokines are small secreted proteins that stimulate the directional migration of leukocytes and mediate inflammation. During screening of a murine choroid plexus complementary DNA library, we identified a new chemokine, designated neurotactin. Unlike other chemokines, neurotactin has a unique cysteine pattern, Cys-X-X-X-Cys, and is predicted to be a type 1 membrane protein. Full-length recombinant neurotactin is localized on the surface of transfected 293 cells. Recombinant neurotactin containing the chemokine domain is chemotactic for neutrophils both in vitro and in vivo. Neurotactin messenger RNA is predominantly expressed in normal murine brain and its protein expression in activated brain microglia is upregulated in mice with experimental autoimmune encephalomyelitis, as well as in mice treated with lipopolysaccharide. Distinct from all other chemokine genes, the neurotactin gene is localized to human chromosome 16q. Consequently we propose that neurotactin represents a new delta-chemokine family and that it may play a role in brain inflammation processes.
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Affiliation(s)
- Y Pan
- Millennium Pharmaceuticals, Inc., Cambridge, Massachusetts 02139, USA.
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6
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McClanahan T, Culpepper J, Campbell D, Wagner J, Franz-Bacon K, Mattson J, Tsai S, Luh J, Guimaraes MJ, Mattei MG, Rosnet O, Birnbaum D, Hannum CH. Biochemical and genetic characterization of multiple splice variants of the Flt3 ligand. Blood 1996; 88:3371-82. [PMID: 8896402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have performed a comprehensive analysis of cell lines and tissues to compare and contrast the expression patterns of Flt3 ligand (FL), c-Kit ligand (KL), and macrophage colony-stimulating factor as well as their receptors, Flt3, c-Kit, and c-Fms. The message for FL is unusually ubiquitous, whereas that of its receptor is quite restricted, apparently limiting the function of the ligand to fetal development and early hematopoiesis. We have also sequenced a mouse FL genomic clone, revealing how the three splice variant FL mRNAs that we have isolated arise. The chromosomal location of the FL gene has been mapped, by in situ hybridization, to chromosome 7 in mouse and chromosome 19 in human. Natural FL protein has been purified from a stromal cell line and shown to be a 65 kD nondisulfide-linked homodimeric glycoprotein comprised of 30 kD subunits, each containing 12 kD of N- and O-linked sugars. Pulse-chase experiments show that one of the splice variants (T110) is responsible for producing the bulk of soluble FL, but only after it has first been expressed at the cell surface as a membrane-bound form. The other splice-variant forms produce molecules that are either obligatorily soluble (T169) or membrane-bound but released only very slowly (T118). Finally, even though most cell lines express some amount of FL mRNA, we found that very little FL protein is actually made, with T cells and stromal cells being the major producers. The data suggests that FL plays its roles over very short distances, perhaps requiring cell-cell contact.
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Affiliation(s)
- T McClanahan
- DNAX Research Institute of Molecular and Cellular Biology, Department of Molecular Biology, Palo Alto, CA 94304, USA
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7
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Kleyn PW, Fan W, Kovats SG, Lee JJ, Pulido JC, Wu Y, Berkemeier LR, Misumi DJ, Holmgren L, Charlat O, Woolf EA, Tayber O, Brody T, Shu P, Hawkins F, Kennedy B, Baldini L, Ebeling C, Alperin GD, Deeds J, Lakey ND, Culpepper J, Chen H, Glücksmann-Kuis MA, Carlson GA, Duyk GM, Moore KJ. Identification and characterization of the mouse obesity gene tubby: a member of a novel gene family. Cell 1996; 85:281-90. [PMID: 8612280 DOI: 10.1016/s0092-8674(00)81104-6] [Citation(s) in RCA: 241] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The mutated gene responsible for the tubby obesity phenotype has been identified by positional cloning. A single base change within a splice donor site results in the incorrect retention of a single intron in the mature tub mRNA transcript. The consequence of this mutation is the substitution of the carboxy-terminal 44 amino acids with 24 intron-encoded amino acids. The normal transcript appears to be abundantly expressed in the hypothalamus, a region of the brain involved in body weight regulation. Variation in the relative abundance of alternative splice products is observed between inbred mouse strains and appears to correlate with an intron length polymorphism. This allele of tub is a candidate for a previously reported diet-induced obesity quantitative trait locus on mouse chromosome 7.
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Affiliation(s)
- P W Kleyn
- Millennium Pharmaceuticals, Inc., Cambridge, Massachusetts 02139, USA
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8
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Chen H, Charlat O, Tartaglia LA, Woolf EA, Weng X, Ellis SJ, Lakey ND, Culpepper J, Moore KJ, Breitbart RE, Duyk GM, Tepper RI, Morgenstern JP. Evidence that the diabetes gene encodes the leptin receptor: identification of a mutation in the leptin receptor gene in db/db mice. Cell 1996; 84:491-5. [PMID: 8608603 DOI: 10.1016/s0092-8674(00)81294-5] [Citation(s) in RCA: 1537] [Impact Index Per Article: 54.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OB-R is a high affinity receptor for leptin, an important circulating signal for the regulation of body weight. We identified an alternatively spliced transcript that encodes a form of mouse OB-R with a long intracellular domain. db/db mice also produce this alternatively spliced transcript, but with a 106 nt insertion that prematurely terminates the intracellular domain. We further identified G --> T point mutation in the genomic OB-R sequence in db/db mice. This mutation generates a donor splice site that converts the 106 nt region to a novel exon retained in the OB-R transcript. We predict that the long intracellular domain form of OB-R is crucial for initiating intracellular signal transduction, and as a corollary, the inability to produce this form of OB-R leads to the severe obese phenotype found in db/db mice.
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Affiliation(s)
- H Chen
- Millennium Pharmaceuticals, Incorporated, Cambridge, Massachusetts 02139, USA
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9
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Tartaglia LA, Dembski M, Weng X, Deng N, Culpepper J, Devos R, Richards GJ, Campfield LA, Clark FT, Deeds J, Muir C, Sanker S, Moriarty A, Moore KJ, Smutko JS, Mays GG, Wool EA, Monroe CA, Tepper RI. Identification and expression cloning of a leptin receptor, OB-R. Cell 1995; 83:1263-71. [PMID: 8548812 DOI: 10.1016/0092-8674(95)90151-5] [Citation(s) in RCA: 2378] [Impact Index Per Article: 82.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The ob gene product, leptin, is an important circulating signal for the regulation of body weight. To identify high affinity leptin-binding sites, we generated a series of leptin-alkaline phosphatase (AP) fusion proteins as well as [125I]leptin. After a binding survey of cell lines and tissues, we identified leptin-binding sites in the mouse choroid plexus. A cDNA expression library was prepared from mouse choroid plexus and screened with a leptin-AP fusion protein to identify a leptin receptor (OB-R). OB-R is a single membrane-spanning receptor most related to the gp130 signal-transducing component of the IL-6 receptor, the G-CSF receptor, and the LIF receptor. OB-R mRNA is expressed not only in choroid plexus, but also in several other tissues, including hypothalamus. Genetic mapping of the gene encoding OB-R shows that it is within the 5.1 cM interval of mouse chromosome 4 that contains the db locus.
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Affiliation(s)
- L A Tartaglia
- Millennium Pharmaceuticals, Incorporated, Cambridge, Massachusetts 02139, USA
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10
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Hudak S, Hunte B, Culpepper J, Menon S, Hannum C, Thompson-Snipes L, Rennick D. FLT3/FLK2 ligand promotes the growth of murine stem cells and the expansion of colony-forming cells and spleen colony-forming units. Blood 1995; 85:2747-55. [PMID: 7537980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The effect of FLT3/FLK2 ligand (FL) on the growth of primitive hematopoietic cells was investigated using ThyloSca1+ stem cells. FL was observed to interact with a variety of factors to initiate colony formation by stem cells. When stem cells were stimulated in liquid culture with FL plus interleukin (IL)-3, IL-6, granulocyte colony-stimulating factor (G-CSF), or stem cell factor (SCF), cells capable of forming colonies in secondary methylcellulose cultures (CFU-c) were produced in high numbers. However, only FL plus IL-6 supported an increase in the number of cells capable of forming colonies in the spleens of irradiated mice (CFU-s). Experiments with accessory cell-depleted bone marrow (Lin- BM) showed that FL alone lacks significant colony-stimulating activity for progenitor cells. Nevertheless, FL enhanced the growth of granulocyte-macrophage progenitors (CFU-GM) in cultures containing SCF, G-CSF, IL-6, or IL-11. In these assays, FL increased the number of CFU-GM initiating colony formation (recruitment), as well as the number of cells per colony (synergy). Many of the colonies were macroscopic and contained greater than 2 x 10(4) granulocytes and macrophages. Therefore, FL appears to function as a potent costimulus for primitive cells of high proliferative potential (HPP). FL was also observed to costimulate the expansion of CFU-GM in liquid cultures of Lin- BM. In contrast, FL had no growth-promoting affects on progenitors committed to the erythrocyte, megakaryocyte, eosinophil, or mast cell lineages.
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Affiliation(s)
- S Hudak
- Department of Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304, USA
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11
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Muench MO, Roncarolo MG, Menon S, Xu Y, Kastelein R, Zurawski S, Hannum CH, Culpepper J, Lee F, Namikawa R. FLK-2/FLT-3 ligand regulates the growth of early myeloid progenitors isolated from human fetal liver. Blood 1995; 85:963-72. [PMID: 7531516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The effects of the recently identified FLK-2/FLT-3 ligand (FL) on the growth of purified human fetal liver progenitors were investigated under serum-deprived culture conditions. FL alone was found to stimulate modest proliferation in short-term cultures of CD34++ CD38+ lineage (Lin)- light-density fetal liver (LDFL) cells and the more primitive CD34++ CD38- Lin- LDFL cells. However, the low levels of growth induced by FL were insufficient for colony formation in clonal cultures. Synergism between FL and either granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) or KIT ligand (KL) was observed in promoting the growth of high-proliferative potential (HPP) colony-forming cells (CF) and/or low-proliferative potential (LPP)-CFC in cultures of CD34++ CD38+ Lin- and CD34++ CD38- Lin- LDFL-cells. FL, alone or in combination with other cytokines, was not found to affect the growth of CD34+ Lin- LDFL cells, the most mature subpopulation of fetal liver progenitors investigated. The growth of the most primitive subset of progenitors studied, CD34++ CD38- Lin- LDFL cells, required the interactions of at least two cytokines, because only very low levels of growth were observed in response to either FL, GM-CSF, IL-3 or KL alone. However, the results of delayed cytokine-addition experiments suggested that individually these cytokines did promote the survival of this early population of progenitors. Although two-factor combinations of FL, KL, and GM-CSF were observed to promote the growth of early progenitors in a synergistic manner, neither of these factors was found to make fetal liver progenitors more responsive to suboptimal concentrations of a second cytokine. Only myeloid cells were recovered from liquid cultures of CD34++ CD38- Lin- LDFL cells grown in the presence of combinations of FL, KL, and GM-CSF. These results indicate that FL is part of a network of growth factors that regulate the growth and survival of early hematopoietic progenitors.
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Affiliation(s)
- M O Muench
- Human Immunology and Molecular Biology Departments, DNAX Research Institute, Palo Alto, CA
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12
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Chang Y, Cesarman E, Pessin MS, Lee F, Culpepper J, Knowles DM, Moore PS. Identification of herpesvirus-like DNA sequences in AIDS-associated Kaposi's sarcoma. Science 1994; 266:1865-9. [PMID: 7997879 DOI: 10.1126/science.7997879] [Citation(s) in RCA: 4016] [Impact Index Per Article: 133.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Representational difference analysis was used to isolate unique sequences present in more than 90 percent of Kaposi's sarcoma (KS) tissues obtained from patients with acquired immunodeficiency syndrome (AIDS). These sequences were not present in tissue DNA from non-AIDS patients, but were present in 15 percent of non-KS tissue DNA samples from AIDS patients. The sequences are homologous to, but distinct from, capsid and tegument protein genes of the Gammaherpesvirinae, herpesvirus saimiri and Epstein-Barr virus. These KS-associated herpesvirus-like (KSHV) sequences appear to define a new human herpesvirus.
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MESH Headings
- Acquired Immunodeficiency Syndrome/complications
- Amino Acid Sequence
- Base Composition
- Base Sequence
- Blotting, Southern
- Cloning, Molecular
- DNA, Viral/analysis
- DNA, Viral/chemistry
- DNA, Viral/genetics
- Female
- Herpesviridae/genetics
- Herpesvirus 2, Saimiriine/genetics
- Herpesvirus 4, Human/genetics
- Humans
- Male
- Molecular Sequence Data
- Nucleic Acid Hybridization
- Open Reading Frames
- Polymerase Chain Reaction
- Retrospective Studies
- Sarcoma, Kaposi/etiology
- Sarcoma, Kaposi/virology
- Sequence Homology, Amino Acid
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Affiliation(s)
- Y Chang
- Department of Pathology, College of Physicians and Surgeons, Columbia University, New York, NY 10032
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13
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Hannum C, Culpepper J, Campbell D, McClanahan T, Zurawski S, Bazan JF, Kastelein R, Hudak S, Wagner J, Mattson J. Ligand for FLT3/FLK2 receptor tyrosine kinase regulates growth of haematopoietic stem cells and is encoded by variant RNAs. Nature 1994; 368:643-8. [PMID: 8145851 DOI: 10.1038/368643a0] [Citation(s) in RCA: 342] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The FLT3/FLK2 receptor tyrosine kinase is closely related to two receptors, c-Kit and c-Fms, which function with their respective ligands, Kit ligand and macrophage colony-stimulating factor to control differentiation of haematopoietic and non-haematopoietic cells. FLT3/FLK2 is thought to be present on haematopoietic stem cells and found in brain, placenta and testis. We have purified to homogeneity and partially sequenced a soluble form of the FLT3/FLK2 ligand produced by mouse thymic stromal cells. We isolated several mouse and human complementary DNAs that encode polypeptides with identical N termini and different C termini. Some variants contain hydrophobic transmembrane segments, suggesting that processing may be required to release soluble ligand. The purified ligand enhances the response of mouse stem cells and a primitive human progenitor cell population to other growth factors such as interleukins IL-3 and IL-6 and to granulocyte-macrophage colony-stimulating factor, and also stimulates fetal thymocytes.
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Affiliation(s)
- C Hannum
- DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, California 94304-1104
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14
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de Waal Malefyt R, Figdor CG, Huijbens R, Mohan-Peterson S, Bennett B, Culpepper J, Dang W, Zurawski G, de Vries JE. Effects of IL-13 on phenotype, cytokine production, and cytotoxic function of human monocytes. Comparison with IL-4 and modulation by IFN-gamma or IL-10. The Journal of Immunology 1993. [DOI: 10.4049/jimmunol.151.11.6370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Recently, we described the cloning and expression of a human cDNA which is the homologue to P600, a gene transcribed by mouse Th2 clones. Based on its activities on human monocytes and B cells this gene was designated IL-13. In the present study we investigated the effects of IL-13 alone or in combination with IL-4, IFN-gamma, or IL-10 on human monocytes. IL-13 induced significant changes in the phenotype of monocytes. Like IL-4, it enhanced the expression of CD11b, CD11c, CD18, CD29, CD49e (VLA-5), class II MHC, CD13, and CD23, whereas it decreased the expression of CD64, CD32, CD16, and CD14 in a dose-dependent manner. IL-13 induced up-regulation of class II MHC Ag and its down-regulatory effects on CD64, CD32, and CD16 expression were prevented by IL-10. IFN-gamma could also partially prevent the IL-13-induced down-regulation of CD64, but not that of CD32 and CD16. However, IL-13 strongly inhibited spontaneous and IL-10- or IFN-gamma-induced ADCC activity of human monocytes toward anti-D coated Rh+ erythrocytes, indicating that the cytotoxic activity of monocytes was inhibited. Furthermore, IL-13 inhibited production of IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, IL-12 p35, IL-12 p40, macrophage inflammatory protein-1 alpha, granulocyte/macrophage-CSF, granulocyte-CSF, IFN-alpha, and TNF alpha by monocytes activated with LPS. In contrast, IL-13 enhanced the production of IL-1 ra by these cells. Similar results on cytokine production were observed or have been obtained with IL-4. Thus IL-13 shares most of its activities on human monocytes with IL-4, but no additive or synergistic effects of IL-4 and IL-13 on human monocytes were observed, suggesting that these cytokines may share common receptor components. Taken together, these results indicate that IL-13 has anti-inflammatory and important immunoregulatory activities.
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Affiliation(s)
- R de Waal Malefyt
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
| | - C G Figdor
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
| | - R Huijbens
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
| | - S Mohan-Peterson
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
| | - B Bennett
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
| | - J Culpepper
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
| | - W Dang
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
| | - G Zurawski
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
| | - J E de Vries
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
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15
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de Waal Malefyt R, Figdor CG, Huijbens R, Mohan-Peterson S, Bennett B, Culpepper J, Dang W, Zurawski G, de Vries JE. Effects of IL-13 on phenotype, cytokine production, and cytotoxic function of human monocytes. Comparison with IL-4 and modulation by IFN-gamma or IL-10. J Immunol 1993; 151:6370-81. [PMID: 7902377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Recently, we described the cloning and expression of a human cDNA which is the homologue to P600, a gene transcribed by mouse Th2 clones. Based on its activities on human monocytes and B cells this gene was designated IL-13. In the present study we investigated the effects of IL-13 alone or in combination with IL-4, IFN-gamma, or IL-10 on human monocytes. IL-13 induced significant changes in the phenotype of monocytes. Like IL-4, it enhanced the expression of CD11b, CD11c, CD18, CD29, CD49e (VLA-5), class II MHC, CD13, and CD23, whereas it decreased the expression of CD64, CD32, CD16, and CD14 in a dose-dependent manner. IL-13 induced up-regulation of class II MHC Ag and its down-regulatory effects on CD64, CD32, and CD16 expression were prevented by IL-10. IFN-gamma could also partially prevent the IL-13-induced down-regulation of CD64, but not that of CD32 and CD16. However, IL-13 strongly inhibited spontaneous and IL-10- or IFN-gamma-induced ADCC activity of human monocytes toward anti-D coated Rh+ erythrocytes, indicating that the cytotoxic activity of monocytes was inhibited. Furthermore, IL-13 inhibited production of IL-1 alpha, IL-1 beta, IL-6, IL-8, IL-10, IL-12 p35, IL-12 p40, macrophage inflammatory protein-1 alpha, granulocyte/macrophage-CSF, granulocyte-CSF, IFN-alpha, and TNF alpha by monocytes activated with LPS. In contrast, IL-13 enhanced the production of IL-1 ra by these cells. Similar results on cytokine production were observed or have been obtained with IL-4. Thus IL-13 shares most of its activities on human monocytes with IL-4, but no additive or synergistic effects of IL-4 and IL-13 on human monocytes were observed, suggesting that these cytokines may share common receptor components. Taken together, these results indicate that IL-13 has anti-inflammatory and important immunoregulatory activities.
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Affiliation(s)
- R de Waal Malefyt
- Department of Human Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304-1104
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Culpepper J, Grieve RB, Friedman L, Mika-Grieve M, Frank GR, Dale B. Molecular characterization of a Dirofilaria immitis cDNA encoding a highly immunoreactive antigen. Mol Biochem Parasitol 1992; 54:51-62. [PMID: 1518532 DOI: 10.1016/0166-6851(92)90094-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Dirofilaria immitis, a filarial nematode, is the causative agent of canine and feline heartworm disease. Previous research has demonstrated that immunity to D. immitis can be induced in dogs by repeated chemical abbreviation of infections while the parasite is a fourth-stage larva. Sera obtained from dogs immunized in this manner has been effective in passively transferring larval killing and stunting. These immune sera, by comparison to nonimmune sera from infected cohorts, recognize a number of unique D. immitis antigens, some of which are larval specific. In this study immune dog sera were used to screen a D. immitis larval cDNA expression library. Three overlapping cDNA clones, Di22, Di18 and Di16, were obtained that encode a portion of a large molecule, greater than 150 kDa, that is composed of multiples of a 399-bp repeat. This protein when immunoblotted with antibody against a recombinant expressed Di22 fusion protein is found in larval as well as adult extracts and excretory-secretory products, and is seen as a series of ascending subunits, each approximately 15 kDa larger than the previous one. This antigen is highly immunogenic, as evidenced by the strong reactivity of the recombinant expressed Di22 fusion protein with sera from immune dogs, microfilaremic dogs and infected amicrofilaremic dogs. While the function of this antigen is unknown it has significant sequence similarity with an allergen found in Ascaris.
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Abstract
The immediate psychophysiological and behavioral effects of photic stimulation on humans [bright light (BL) of 5K lux or dim light (DL) of 50 lux] were assessed in male subjects (N = 43) under four different conditions. For one condition the same subjects (N = 16) received alternating 90-min blocks of BL and DL during the nighttime h (2300-0800 h) under sustained wakefulness conditions. A second condition was similar to the first except that subjects (N = 8) received photic stimulation during the daytime hours. For the third and fourth conditions different subjects received either continuous BL (N = 10) or continuous DL (N = 9) during the nighttime hours. For the nighttime alternating condition body temperature decreased under DL but either increased or maintained under BL. For the continuous light condition, body temperature dropped sharply across the night under DL but dropped only slightly under BL. Sleepiness was considerably greater under DL than under BL, and the difference became larger as the night progressed. Similarly, alertness, measured by EEG beta activity, was greater under BL, and nighttime performance on behavioral tasks was also generally better. There were no differential effects between BL and DL on any measure during the daytime. These data indicate that light exerts a powerful, immediate effect on physiology and behavior in addition to its powerful influence on circadian organization.
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Affiliation(s)
- P Badia
- Psychology Department, Bowling Green State University, OH 43403
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Abstract
Whether humans react to olfactory stimuli presented in sleep was assessed. Responses of ten participants (mean age = 22.8 years) were recorded to repeated three-minute periods of either air alone or to a peppermint odor (0.26 mg/liter) during stage 2 sleep. These responses included behavioral (awakening, microswitch closure), autonomic (heart rate, EMG, respiration), and central (EEG) components. An odor delivery system is described comprised of an aquarium pump, Teflon and TYGON tubing, oxygen mask, filtering, and air flow valves. The data indicate that humans react behaviorally, autonomically and centrally to olfactory stimuli presented while sleeping. Although the percentage of overall responsivity to olfactory stimuli was low, significant differences (ANOVA) in responsivity to odor periods vs. nonodor periods were found for microswitch closures, EEG, EMG, and heart rate. For these measures eight or more of the ten participants showed this pattern of differential responsivity during odor and nonodor periods (Sign test = p less than 0.05). A time-of-night effect was also observed in that responsivity tended to be greatest early in the night. The effect on responsivity of other durations, concentrations, and odors requires additional research.
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Affiliation(s)
- P Badia
- Psychology Department, Bowling Green State University, OH 43403
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Abstract
Behavioral control of abnormal breathing in sleep was studied to determine if an intervention procedure could reduce apnea duration and also SaO2 (blood oxygen) desaturation levels. Sleep apnea patients (n = 11) were instructed while awake that tones would be presented in sleep whenever an apnea event occurred. They were told to breathe deeply to the tones and were given practice in doing so. Intervention and nonintervention hours alternated across 2 nights following 2 baseline nights. As expected, during the intervention hours, the duration but not the frequency of apneic events was reduced. The procedure also resulted in higher SaO2 levels during the intervention hours. Daytime sleepiness was not greater following intervention but sleep staging effects were observed. The results are sufficiently promising to warrant additional research.
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Affiliation(s)
- P Badia
- Department of Psychology, Bowling Green State University, Ohio 43403
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Abstract
Many parasites, including most of those of medical or veterinary importance, experience a major increase in ambient temperature at some stage during their life cycle. This occurs when a cyst or free-living larval form is ingested by a warm-blooded host, when a poikilotherm-infecting parasite is transmitted to a homeotherm, or when a transiently free-living invasive larva penetrates the skin of a mammal. This sudden change in temperature could be expected to stress the intruder, as it should dramatically alter rates of metabolic reactions and of denaturation of proteins. This would especially affect the function of near-equilibrium, regulatory, and membrane-bound enzymes (changes in temperature affect membrane fluidity). In this article George Newport, Janice Culpepper and Nina Agabian consider how parasites cope with this problem, emphasizing the possible role of heat-shock proteins (HSPs), how the expression of these molecules is regulate, and how HSPs interact with the host immune system.
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Affiliation(s)
- G Newport
- Department of Pharmaceutical Chemistry, University of California at San Francisco, Laurel Heights Campus, 3333 California Street, San Francisco, CA 94143, USA
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Abstract
Constitutively expressed schistosome homologues of heat-shock protein Hsp70 elicit a dominant antibody response in humans infected with either Schistosoma japonicum or Schistosoma mansoni; in each case the parasite antigens are immunologically distinct and noncrossreactive. The antigenic site of the homologues is located near their carboxyl terminus where phylogenetic divergence between Hsp70 proteins is greatest. Nucleotide sequence comparison between these regions predicts very few amino acid differences between the schistosome protein and that of their human host. Thus strikingly limited diversity is sufficient to elicit a discriminatory antibody response to these parasite host-like antigens.
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Affiliation(s)
- R Hedstrom
- School of Public Health, Naval Biosciences Laboratory, University of California, Berkeley
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Abstract
This study evaluated whether muscle tension could be controlled during sleep. Twelve volunteers were assigned to an experimental condition or to a no treatment control group. Experimental subjects were instructed to reduce the tension in their masseter (jaw) muscle when signalled with an auditory tone. These subjects demonstrated cue-controlled tension reductions during awake training sessions. Although both groups evidenced muscle tension increases in response to the tones presented during sleep, experimental subjects produced significantly smaller increases in response to tone stimuli than did control subjects. More importantly, experimental subjects sustained lower tonic levels of muscle tension throughout the sleep sessions than did control subjects. Sleep was moderately disrupted for subjects in both groups. However, experimental subjects evidenced the greatest tension reductions during those responses in which they shifted to a lighter stage of sleep rather than fully awakening. These data suggest that muscle tension can be moderated during sleep.
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Affiliation(s)
- D O'Rourke
- Department of Psychology, University of Southern Mississippi, Hattiesburg 39401
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Hedstrom R, Culpepper J, Harrison RA, Agabian N, Newport G. A major immunogen in Schistosoma mansoni infections is homologous to the heat-shock protein Hsp70. J Exp Med 1987; 165:1430-5. [PMID: 3106556 PMCID: PMC2188310 DOI: 10.1084/jem.165.5.1430] [Citation(s) in RCA: 101] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
A 70,000 mol wt protein of Schistosoma mansoni was shown to be a major immunogen that invariably elicited an antibody response in infected humans. The universality of the response to this abundant antigen was confirmed in experimental animals and included the antibody response associated with the protective irradiated cercarial vaccine. We identified the 70,000 mol wt antigen as an S. mansoni homologue of the major eukaryotic heat-shock protein hsp70 by DNA sequence analysis of a cDNA insert from a lambda gt11 clone expressing the antigen and located the immunodominant epitope near the COOH-terminus of the molecule. The antigenic relationship of hsp70 to schistosome infections suggested an important role for this protein in parasite development and pathogenesis.
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Abstract
A new flexible implantation system for endobronchial brachytherapy is described. This system was used to implant Au-198 seeds in the endobronchial tumors of two patients; discomfort and morbidity were minimal. The flexible injector system may be an improvement over the rigid system for endobronchial implantation in most patients.
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Snyder JV, Pennock B, Herbert D, Rinaldo JE, Culpepper J, Good WF, Gur D. Local lung ventilation in critically ill patients using nonradioactive xenon-enhanced transmission computed tomography. Crit Care Med 1984; 12:46-51. [PMID: 6360534 DOI: 10.1097/00003246-198401000-00013] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Nonradioactive xenon is sufficiently radiodense to increase the density of gas-containing lung as seen in a computed tomography (CT) scan. Subtraction of a baseline CT scan from the xenon-enhanced CT scan can accentuate gas space differences by subtracting fixed tissue densities. The baseline scan and the scan obtained during wash-in of xenon (before equilibration) allow circulation of local ventilation. The xenon CT scan, thus, provides more precise information about distribution of ventilation than planar radiogas techniques. The technical aspects of application to a critically ill patient and the mathematical basis of the technique are presented.
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