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Grieco SF, Johnston KG, Gao P, Garduño BM, Tang B, Yi E, Sun Y, Horwitz GD, Yu Z, Holmes TC, Xu X. Anatomical and molecular characterization of parvalbumin-cholecystokinin co-expressing inhibitory interneurons: implications for neuropsychiatric conditions. Mol Psychiatry 2023; 28:5293-5308. [PMID: 37443194 DOI: 10.1038/s41380-023-02153-5] [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] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/15/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023]
Abstract
Inhibitory interneurons are crucial to brain function and their dysfunction is implicated in neuropsychiatric conditions. Emerging evidence indicates that cholecystokinin (CCK)-expressing interneurons (CCK+) are highly heterogenous. We find that a large subset of parvalbumin-expressing (PV+) interneurons express CCK strongly; between 40 and 56% of PV+ interneurons in mouse hippocampal CA1 express CCK. Primate interneurons also exhibit substantial PV/CCK co-expression. Mouse PV+/CCK+ and PV+/CCK- cells show distinguishable electrophysiological and molecular characteristics. Analysis of single nuclei RNA-seq and ATAC-seq data shows that PV+/CCK+ cells are a subset of PV+ cells, not of synuclein gamma positive (SNCG+) cells, and that they strongly express oxidative phosphorylation (OXPHOS) genes. We find that mitochondrial complex I and IV-associated OXPHOS gene expression is strongly correlated with CCK expression in PV+ interneurons at both the transcriptomic and protein levels. Both PV+ interneurons and dysregulation of OXPHOS processes are implicated in neuropsychiatric conditions, including autism spectrum (ASD) disorder and schizophrenia (SCZ). Analysis of human brain samples from patients with these conditions shows alterations in OXPHOS gene expression. Together these data reveal important molecular characteristics of PV-CCK co-expressing interneurons and support their implication in neuropsychiatric conditions.
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Affiliation(s)
- Steven F Grieco
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
- Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA
| | - Kevin G Johnston
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
- Department of Mathematics, School of Physical Sciences, University of California, Irvine, CA, 92697, USA
| | - Pan Gao
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - B Maximiliano Garduño
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Bryan Tang
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Elsie Yi
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Yanjun Sun
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Gregory D Horwitz
- Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, 98195, USA
| | - Zhaoxia Yu
- Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA
- Department of Statistics, Donald Bren School of Information and Computer Sciences, University of California, Irvine, CA, 92697, USA
| | - Todd C Holmes
- Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA.
- Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA.
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA, 92697, USA.
- Department of Biomedical Engineering, University of California, Irvine, CA, 92697, USA.
- Department of Computer Science, University of California, Irvine, CA, 92697, USA.
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2
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Zhao W, Johnston KG, Ren H, Xu X, Nie Q. Inferring neuron-neuron communications from single-cell transcriptomics through NeuronChat. Nat Commun 2023; 14:1128. [PMID: 36854676 PMCID: PMC9974942 DOI: 10.1038/s41467-023-36800-w] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/15/2023] [Indexed: 03/02/2023] Open
Abstract
Neural communication networks form the fundamental basis for brain function. These communication networks are enabled by emitted ligands such as neurotransmitters, which activate receptor complexes to facilitate communication. Thus, neural communication is fundamentally dependent on the transcriptome. Here we develop NeuronChat, a method and package for the inference, visualization and analysis of neural-specific communication networks among pre-defined cell groups using single-cell expression data. We incorporate a manually curated molecular interaction database of neural signaling for both human and mouse, and benchmark NeuronChat on several published datasets to validate its ability in predicting neural connectivity. Then, we apply NeuronChat to three different neural tissue datasets to illustrate its functionalities in identifying interneural communication networks, revealing conserved or context-specific interactions across different biological contexts, and predicting communication pattern changes in diseased brains with autism spectrum disorder. Finally, we demonstrate NeuronChat can utilize spatial transcriptomics data to infer and visualize neural-specific cell-cell communication.
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Affiliation(s)
- Wei Zhao
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA, 92697, USA
| | - Kevin G Johnston
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA, 92697, USA
| | - Honglei Ren
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA, 92697, USA
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA.,Department of Biomedical Engineering, University of California, Irvine, CA, 92697, USA.,Department of Computer Science, University of California, Irvine, CA, 92697, USA.,The Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA
| | - Qing Nie
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA, 92697, USA. .,Department of Biomedical Engineering, University of California, Irvine, CA, 92697, USA. .,The Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA. .,Department of Developmental and Cell Biology, University of California, Irvine, CA, 92697, USA.
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Zhao W, Johnston KG, Ren H, Xu X, Nie Q. Inferring neuron-neuron communications from single-cell transcriptomics through NeuronChat. bioRxiv 2023:2023.01.12.523826. [PMID: 36712056 PMCID: PMC9882151 DOI: 10.1101/2023.01.12.523826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Neural communication networks form the fundamental basis for brain function. These communication networks are enabled by emitted ligands such as neurotransmitters, which activate receptor complexes to facilitate communication. Thus, neural communication is fundamentally dependent on the transcriptome. Here we develop NeuronChat, a method and package for the inference, visualization and analysis of neural-specific communication networks among pre-defined cell groups using single-cell expression data. We incorporate a manually curated molecular interaction database of neural signaling for both human and mouse, and benchmark NeuronChat on several published datasets to validate its ability in predicting neural connectivity. Then, we apply NeuronChat to three different neural tissue datasets to illustrate its functionalities in identifying interneural communication networks, revealing conserved or context-specific interactions across different biological contexts, and predicting communication pattern changes in diseased brains with autism spectrum disorder. Finally, we demonstrate NeuronChat can utilize spatial transcriptomics data to infer and visualize neural-specific cell-cell communication.
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Affiliation(s)
- Wei Zhao
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697
| | - Kevin G Johnston
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697
| | - Honglei Ren
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697.,Department of Biomedical Engineering, University of California, Irvine, CA 92697.,Department of Computer Science, University of California, Irvine, CA 92697.,The Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA 92697.,The Center for Neural Circuit Mapping, University of California, Irvine, CA 92697
| | - Qing Nie
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697.,Department of Developmental and Cell Biology, University of California, Irvine, CA 92697.,Department of Biomedical Engineering, University of California, Irvine, CA 92697.,The Center for Neural Circuit Mapping, University of California, Irvine, CA 92697
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4
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Zhang H, Chen L, Johnston KG, Crapser J, Green KN, Ha NML, Tenner AJ, Holmes TC, Nitz DA, Xu X. Degenerate mapping of environmental location presages deficits in object-location encoding and memory in the 5xFAD mouse model for Alzheimer's disease. Neurobiol Dis 2023; 176:105939. [PMID: 36462718 PMCID: PMC10187684 DOI: 10.1016/j.nbd.2022.105939] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 11/08/2022] [Accepted: 11/30/2022] [Indexed: 12/03/2022] Open
Abstract
A key challenge in developing diagnosis and treatments for Alzheimer's disease (AD) is to detect abnormal network activity at as early a stage as possible. To date, behavioral and neurophysiological investigations in AD model mice have yet to conduct a longitudinal assessment of cellular pathology, memory deficits, and neurophysiological correlates of neuronal activity. We therefore examined the temporal relationships between pathology, neuronal activities and spatial representation of environments, as well as object location memory deficits across multiple stages of development in the 5xFAD mice model and compared these results to those observed in wild-type mice. We performed longitudinal in vivo calcium imaging with miniscope on hippocampal CA1 neurons in behaving mice. We find that 5xFAD mice show amyloid plaque accumulation, depressed neuronal calcium activity during immobile states, and degenerate and unreliable hippocampal neuron spatial tuning to environmental location at early stages by 4 months of age while their object location memory (OLM) is comparable to WT mice. By 8 months of age, 5xFAD mice show deficits of OLM, which are accompanied by progressive degradation of spatial encoding and, eventually, impaired CA1 neural tuning to object-location pairings. Furthermore, depressed neuronal activity and unreliable spatial encoding at early stage are correlated with impaired performance in OLM at 8-month-old. Our results indicate the close connection between impaired hippocampal tuning to object-location and the presence of OLM deficits. The results also highlight that depressed baseline firing rates in hippocampal neurons during immobile states and unreliable spatial representation precede object memory deficits and predict memory deficits at older age, suggesting potential early opportunities for AD detecting.
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Affiliation(s)
- Hai Zhang
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America
| | - Lujia Chen
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America; Department of Biomedical Engineering, University of California, Irvine, CA 92697, United States of America
| | - Kevin G Johnston
- Department of Mathematics, University of California, Irvine, CA 92697, United States of America
| | - Joshua Crapser
- Department of Neurobiology and Behavior, School of Biological Sciences, University of California, Irvine, CA 92697, United States of America
| | - Kim N Green
- Department of Neurobiology and Behavior, School of Biological Sciences, University of California, Irvine, CA 92697, United States of America; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, United States of America
| | - Nicole My-Linh Ha
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America
| | - Andrea J Tenner
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California, Irvine, CA 92697, United States of America
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA 92697, United States of America; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, United States of America
| | - Douglas A Nitz
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA 92093, United States of America; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, United States of America.
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, United States of America; Department of Biomedical Engineering, University of California, Irvine, CA 92697, United States of America; Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, United States of America.
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5
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Johnston KG, Grieco SF, Zhang H, Jin S, Xu X, Nie Q. Tracking longitudinal population dynamics of single neuronal calcium signal using SCOUT. Cell Rep Methods 2022; 2:100207. [PMID: 35637911 PMCID: PMC9142684 DOI: 10.1016/j.crmeth.2022.100207] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 01/06/2022] [Accepted: 04/08/2022] [Indexed: 11/07/2022]
Abstract
In vivo calcium imaging enables simultaneous recording of large neuronal ensembles engaged in complex operations. Many experiments require monitoring and identification of cell populations across multiple sessions. Population cell tracking across multiple sessions is complicated by non-rigid transformations induced by cell movement and imaging field shifts. We introduce SCOUT (Single-Cell spatiOtemporal longitUdinal Tracking), a fast, robust cell-tracking method utilizing multiple cell-cell similarity metrics, probabilistic inference, and an adaptive clustering methodology, to perform cell identification across multiple sessions. By comparing SCOUT with earlier cell-tracking algorithms on simulated, 1-photon, and 2-photon recordings, we show that our approach significantly improves cell-tracking quality, particularly when recordings exhibit spatial footprint movement between sessions or sub-optimal neural extraction quality.
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Affiliation(s)
- Kevin G. Johnston
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697, USA
| | - Steven F. Grieco
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, USA
| | - Hai Zhang
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, USA
| | - Suoqin Jin
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697, USA
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697, USA
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
- Department of Computer Science, University of California, Irvine, CA 92697, USA
- The Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA 92697, USA
- The Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, USA
| | - Qing Nie
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697, USA
- Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA
- Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
- The Center for Neural Circuit Mapping, University of California, Irvine, CA 92697, USA
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6
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Grieco SF, Qiao X, Johnston KG, Chen L, Nelson RR, Lai C, Holmes TC, Xu X. Neuregulin signaling mediates the acute and sustained antidepressant effects of subanesthetic ketamine. Transl Psychiatry 2021; 11:144. [PMID: 33627623 PMCID: PMC7904825 DOI: 10.1038/s41398-021-01255-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/09/2021] [Accepted: 02/01/2021] [Indexed: 01/03/2023] Open
Abstract
Subanesthetic ketamine evokes rapid antidepressant effects in human patients that persist long past ketamine's chemical half-life of ~2 h. Ketamine's sustained antidepressant action may be due to modulation of cortical plasticity. We find that ketamine ameliorates depression-like behavior in the forced swim test in adult mice, and this depends on parvalbumin-expressing (PV) neuron-directed neuregulin-1 (NRG1)/ErbB4 signaling. Ketamine rapidly downregulates NRG1 expression in PV inhibitory neurons in mouse medial prefrontal cortex (mPFC) following a single low-dose ketamine treatment. This NRG1 downregulation in PV neurons co-tracks with the decreases in synaptic inhibition to mPFC excitatory neurons for up to a week. This results from reduced synaptic excitation to PV neurons, and is blocked by exogenous NRG1 as well as by PV targeted ErbB4 receptor knockout. Thus, we conceptualize that ketamine's effects are mediated through rapid and sustained cortical disinhibition via PV-specific NRG1 signaling. Our findings reveal a novel neural plasticity-based mechanism for ketamine's acute and long-lasting antidepressant effects.
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Affiliation(s)
- Steven F. Grieco
- grid.266093.80000 0001 0668 7243Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697-1275 USA
| | - Xin Qiao
- grid.266093.80000 0001 0668 7243Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697-1275 USA
| | - Kevin G. Johnston
- grid.266093.80000 0001 0668 7243Department of Mathematics, University of California, Irvine, CA 92697-3875 USA
| | - Lujia Chen
- grid.266093.80000 0001 0668 7243Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697-1275 USA
| | - Renetta R. Nelson
- grid.266093.80000 0001 0668 7243Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697-1275 USA
| | - Cary Lai
- grid.411377.70000 0001 0790 959XDepartment of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405-7000 USA
| | - Todd C. Holmes
- grid.19006.3e0000 0000 9632 6718Department of Physiology and Biophysics, School of Medicine, Universityof California, Irvine, CA 92697- 4560 USA ,grid.266093.80000 0001 0668 7243The Center for Neural Circuit Mapping, University of California, Irvine, CA 92697 USA
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697-1275, USA. .,The Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA. .,Department of Biomedical Engineering, University of California, Irvine, CA, 92697-2715, USA. .,Department of Microbiology and Molecular Genetics, University of California, Irvine, CA, 92697-4025, USA. .,Department of Computer Science, University of California, Irvine, CA, 92697-3435, USA.
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7
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Sun Y, Jin S, Lin X, Chen L, Qiao X, Jiang L, Zhou P, Johnston KG, Golshani P, Nie Q, Holmes TC, Nitz DA, Xu X. CA1-projecting subiculum neurons facilitate object-place learning. Nat Neurosci 2019; 22:1857-1870. [PMID: 31548723 PMCID: PMC6819262 DOI: 10.1038/s41593-019-0496-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 08/09/2019] [Indexed: 11/09/2022]
Abstract
Recent anatomical evidence suggests a functionally significant back-projection pathway from the subiculum to the CA1. Here we show that the afferent circuitry of CA1-projecting subicular neurons is biased by inputs from CA1 inhibitory neurons and the visual cortex, but lacks input from the entorhinal cortex. Efferents of the CA1-projecting subiculum neurons also target the perirhinal cortex, an area strongly implicated in object-place learning. We identify a critical role for CA1-projecting subicular neurons in object-location learning and memory, and show that this projection modulates place-specific activity of CA1 neurons and their responses to displaced objects. Together, these experiments reveal a novel pathway by which cortical inputs, particularly those from the visual cortex, reach the hippocampal output region CA1. Our findings also implicate this circuitry in the formation of complex spatial representations and learning of object-place associations.
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Affiliation(s)
- Yanjun Sun
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA.,Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Suoqin Jin
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Xiaoxiao Lin
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Lujia Chen
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Xin Qiao
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Li Jiang
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Pengcheng Zhou
- Department of Statistics and Center for Theoretical Neuroscience, Columbia University, New York, NY, USA
| | - Kevin G Johnston
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.,West Los Angeles VA Medical Center, Los Angeles, CA, USA
| | - Qing Nie
- Department of Mathematics and Department of Developmental & Cell Biology, University of California, Irvine, Irvine, CA, USA.,Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA, USA
| | - Douglas A Nitz
- Department of Cognitive Science, University of California, San Diego, La Jolla, CA, USA.
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, USA. .,Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA. .,Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA, USA. .,Department of Computer Science, University of California, Irvine, Irvine, CA, USA.
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Abstract
A survey of 2 horse populations was done to detect the number of asymptomatic faecal excretors of Salmonella sp. 1201 faecal samples from 250 horses hospitalised at the University of Sydney were cultured. Three serotypes, S. typhimurium (4 horses), S. anatum (2) and S. tennessee (1) were isolated from 7 horses (2.8%). None was detected in 75 mares similarly examined at a thoroughbred stud farm. In retrospect, S. typhimurium was also the most common (70%) of the 19 serotypes recovered from 171 horses with clinical salmonellosis seen at Camden, 1969 to 1986. Forty cases occurring since 1983 were reviewed in detail; the mortality rate was high (60%) and an increased proportion was due to S. bovis-morbificans. Five horses developed salmonellosis while hospitalised and it was usually impossible to be certain whether these cases developed from the carrier state into overt disease or resulted from infections acquired in hospital.
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Affiliation(s)
- A P Begg
- University of Sydney, Department of Veterinary Clinical Studies, Camden, New South Wales
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Johnston KG, English AW. A small episode of single quarter coliform infections in lactating dairy cows kept at pasture. Aust Vet J 1984; 61:364-6. [PMID: 6397184 DOI: 10.1111/j.1751-0813.1984.tb07157.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
For a period of 150 days, an Escherichia coli infection in a single quarter of the udder of 13 cows occurred on average every 9 days, in a herd of 120 cows kept at pasture under temperate environmental conditions. Most cases were clinically mild, affecting cows in lactations 1 to 10 and at all stages of lactation; none were evident at calving. Samples of secretion from infected quarters sometimes had few demonstrable organisms. Eleven different serotypes in 8 (0) groups were recovered; one isolate was multiply resistant to antibiotics and one infection persisted for 120 days. A precise explanation for this episodic exacerbation of the new infection rate was not established, but probable contributing factors were recognised.
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11
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Abstract
Abstract
A solid-phase reagent for determination of urinary specific gravity (relative density) is described. This reagent strip, similar to others in the "N-Multistix" series (Ames), contains a polyacid whose acidity is sensitive to the ionic concentration in the urine in which it is immersed. As the acidity of the polyacid changes, pH changes are detected by a pH indicator within the reagent strip. In comparison studies, 84.4% of relative densities as measured with these reagent strips were within 0.005 of the corresponding results with a total-solids meter, and 89.9% were within 0.005 of the corresponding urinometer results. Adding a correction of +0.005 to the reagent-strip results for urines with high pH increased the percentage of results within 0.005 of the comparison method to 90.7% (TS meter) and 92.9% (urinometer). Lot-to-lot variability and reader-to-reader variability were both low. Reagent strip results are not affected by glucose, may be increased by albumin, and correlate with urea concentrations.
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12
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Burkhardt AE, Johnston KG, Waszak CE, Jackson CE, Shafer SR. A reagent strip for measuring the specific gravity of urine. Clin Chem 1982; 28:2068-72. [PMID: 7127735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A solid-phase reagent for determination of urinary specific gravity (relative density) is described. This reagent strip, similar to others in the "N-Multistix" series (Ames), contains a polyacid whose acidity is sensitive to the ionic concentration in the urine in which it is immersed. As the acidity of the polyacid changes, pH changes are detected by a pH indicator within the reagent strip. In comparison studies, 84.4% of relative densities as measured with these reagent strips were within 0.005 of the corresponding results with a total-solids meter, and 89.9% were within 0.005 of the corresponding urinometer results. Adding a correction of +0.005 to the reagent-strip results for urines with high pH increased the percentage of results within 0.005 of the comparison method to 90.7% (TS meter) and 92.9% (urinometer). Lot-to-lot variability and reader-to-reader variability were both low. Reagent strip results are not affected by glucose, may be increased by albumin, and correlate with urea concentrations.
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Abstract
Cells in the peritoneal fluid from 159 horses were examined in Giemsa stained preparations using light microscopy. Normal mesothelial cells showed an oval nucleus with finely reticular chromatin and pale blue cytoplasm. Activated mesothelial cells occurred in fluids derived from mesothelium under acute or subacute, non-septic stimulus and were remarkable for their pleomorphism and intense basophilia which may mimic neoplasia. Transformed mesothelial cells seen in chronic inflammatory fluids were sometimes phagocytic and showed conspicuous cytoplasmic vacuolation.
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Abstract
Twenty horses, aged one to 17 years (mean age 6 years), presented for elective destruction and subsequently found at autopsy to have no significant peritoneal alterations, were used to determine a variety of reference values for peritoneal fluid. Samples were collected ante mortem or within 1 h post mortem. Each cavity contained 100 to 300 ml of usually clear, pale yellow fluid which in a clinical refractometer showed a mean specific gravity 1.010 (range 1.0081-1.0116) and mean (+/- standard deviation) total protein 7.7 +/- 3.6 g/litre. The mean total nucleated cell count (+/- sd) was 4.33 +/- 2.5 x 10(9)/litre (range 1.5-10.1 x 10(9)/litre) and, proportionally, polymorphonuclear leucocytes averaged 45.2 per cent, mononuclear phagocytes 47 per cent, lymphocytes 7.8 per cent, eosinophils 0.7 per cent and basophils and mast cells zero. Eosinophils were not usually seen but 6 samples had 1 to 5 per cent. The peritoneal fluid chemical profile (mean +/- sd) was: Aspartate aminotransferase (AST) 118.9 +/- 46.9 iu/litre; alkaline phosphatase (AP) 56.0 +/- 52.7 iu/litre; lactate dehydrogenase (LDH) 143.0 +/- 106.1 iu/litre; total bilirubin (TB) 8.0 +/- 6.2 mumol/litre; total protein (TP) (biuret method) 14.2 +/- 6.8 g/litre; urea nitrogen (BUN) 6.1 +/- 1.1 mmol/litre; glucose 7.7 +/- 1.8 mmol/litre; inorganic phosphate (IP) 1.4 +/- 0.5 mmol/litre; calcium 2.0 +/- 0.2 mmol/litre. TP, BUN, glucose and IP were closely correlated with levels in paired serum samples.
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Abstract
Neisseria dentrificans possesses an inducible sucrose-uptake system. Sucrose is transported as the free sugar and is rapidly converted into polymerized material. Uptake is inhibited by glucose, cyanide, uncouplers of oxidative phosphorylation, and sulfydryl reagents. Glutamate serves as an energy source for uptake. The importance of this phenomenon in the oral environment is discussed.
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Abstract
A lactose fermenting strain of Salmonella typhimurium was isolated from two calves which died during an outbreak of acute enteritis. The organism was biochemically typical in all other respects. In one calf, uncomplicated by treatment before death, the autopsy findings were those of a severe fibrinous enteritis which was reproduced in another calf dosed orally with culture. Attention is drawn to scattered reports of lactose fermenting salmonelle causing morbidity and mortality in calves and man.
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Johnston KG. The orf viruses in man and animals. Australas J Dermatol 1967; 9:122-31. [PMID: 4297745 DOI: 10.1111/j.1440-0960.1967.tb01294.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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