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Guerrero-Muñoz J, Medina L, Castillo C, Liempi A, Fernández-Moya A, Araneda S, Ortega Y, Rojas-Pirela M, Maya JD, Kemmerling U. MicroRNA-512-3p mediates Trypanosoma cruzi-induced apoptosis during ex vivo infection of human placental explants. Placenta 2023; 143:117-123. [PMID: 37898020 DOI: 10.1016/j.placenta.2023.10.009] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 09/25/2023] [Accepted: 10/16/2023] [Indexed: 10/30/2023]
Abstract
INTRODUCTION Upon infection, Trypanosoma cruzi, a protozoan parasite, crosses the placental barrier and causes congenital Chagas disease. Ex vivo infection of human placental explants (HPEs) with the parasite induces apoptotic cell death. This cellular process involves changes in gene expression, which are partially regulated by miRNAs. In this study, we investigated the role of miR-512-3p, a highly expressed miRNA in the placenta, in parasite-induced apoptosis. METHODS HPE cells were transfected with antagomirs or mimics of miR-512-3p and subsequently challenged with the parasite. The expression levels of miR-512-3p, caspase 3, caspase 8, and Livin were measured using RT-qPCR, and apoptotic cell death was analyzed based on caspase activity and DNA fragmentation assays. RESULTS Targeted inhibition of miR-512-3p effectively prevented parasite-induced expression and enzymatic activity of caspase 3 and caspase 8. However, it did not completely prevent DNA fragmentation, indicating the involvement of other factors in this process. Furthermore, the findings suggest that Livin may be regulated by miR-512-3p. DISCUSSION Our findings suggest that miR-512-3p modulates parasite-induced apoptosis in the trophoblast. By understanding the mechanisms involved in this process, we can gain insights into the pathogenesis of congenital Chagas disease and develop targeted therapeutic strategies.
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Affiliation(s)
- Jesús Guerrero-Muñoz
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Lisvaneth Medina
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Christian Castillo
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Núcleo de Investigación Aplicada en Ciencias Veterinarias y Agronómicas, Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Chile
| | - Ana Liempi
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Alejandro Fernández-Moya
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Sebastian Araneda
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Departamento de Patología y Medicina oral, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Yessica Ortega
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Facultad de Farmacia y Bioanálisis, Universidad de Los Andes, Mérida, Venezuela
| | - Maura Rojas-Pirela
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Juan Diego Maya
- Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ulrike Kemmerling
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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Medina L, Guerrero-Muñoz J, Castillo C, Liempi A, Fernández-Moya A, Araneda S, Ortega Y, Rivas C, Maya JD, Kemmerling U. Differential microRNAs expression during ex vivo infection of canine and ovine placental explants with Trypanosoma cruzi and Toxoplasma gondii. Acta Trop 2022; 235:106651. [PMID: 35964709 DOI: 10.1016/j.actatropica.2022.106651] [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: 05/27/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 11/25/2022]
Abstract
Trypanosoma cruzi and Toxoplasma gondii are two zoonotic parasites that constitute significant human and animal health threats, causing a significant economic burden worldwide. Both parasites can be transmitted congenitally, but transmission rates for T. gondii are high, contrary to what has been observed for T. cruzi. The probability of congenital transmission depends on complex interactions between the pathogen and the host, including the modulation of host cell gene expression by miRNAs. During ex vivo infection of canine and ovine placental explants, we evaluated the expression of 3 miRNAs (miR-30e-3p, miR-3074-5p, and miR-127-3p) previously associated with parasitic and placental diseases and modulated by both parasites. In addition, we identified the possible target genes of the miRNAs by using computational prediction tools and performed GO and KEGG enrichment analyses to identify the biological functions and associated pathologies. The three miRNAs are differentially expressed in the canine and ovine placenta in response to T. cruzi and T. gondii. We conclude that the observed differential expression and associated functions might explain, at least partially, the differences in transmission rates and susceptibility to parasite infection in different species.
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Affiliation(s)
- Lisvaneth Medina
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Jesús Guerrero-Muñoz
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Christian Castillo
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Núcleo de Investigación Aplicada en Ciencias Veterinarias y Agronómicas, Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Chile
| | - Ana Liempi
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Alejandro Fernández-Moya
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Sebastian Araneda
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Departamento de Patología y Medicina Oral, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Yessica Ortega
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Facultad de Farmacia y Bioanálisis, Universidad de Los Andes, Mérida, Venezuela
| | - Cristian Rivas
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Juan Diego Maya
- Programa de Farmacología Molecular y Clínica, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ulrike Kemmerling
- Programa de Biología Integrativa, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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Rojas-Pirela M, Andrade-Alviárez D, Medina L, Castillo C, Liempi A, Guerrero-Muñoz J, Ortega Y, Maya JD, Rojas V, Quiñones W, Michels PA, Kemmerling U. MicroRNAs: master regulators in host-parasitic protist interactions. Open Biol 2022; 12:210395. [PMID: 35702995 PMCID: PMC9198802 DOI: 10.1098/rsob.210395] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
MicroRNAs (miRNAs) are a group of small non-coding RNAs present in a wide diversity of organisms. MiRNAs regulate gene expression at a post-transcriptional level through their interaction with the 3' untranslated regions of target mRNAs, inducing translational inhibition or mRNA destabilization and degradation. Thus, miRNAs regulate key biological processes, such as cell death, signal transduction, development, cellular proliferation and differentiation. The dysregulation of miRNAs biogenesis and function is related to the pathogenesis of diseases, including parasite infection. Moreover, during host-parasite interactions, parasites and host miRNAs determine the probability of infection and progression of the disease. The present review is focused on the possible role of miRNAs in the pathogenesis of diseases of clinical interest caused by parasitic protists. In addition, the potential role of miRNAs as targets for the design of drugs and diagnostic and prognostic markers of parasitic diseases is also discussed.
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Affiliation(s)
- Maura Rojas-Pirela
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile,Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile,Facultad de Farmacia y Bioanálisis, Universidad de Los Andes, Mérida, Venezuela
| | - Diego Andrade-Alviárez
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | - Lisvaneth Medina
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
| | - Christian Castillo
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile,Núcleo de Investigación Aplicada en Ciencias Veterinarias y Agronómicas, Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Chile
| | - Ana Liempi
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
| | - Jesús Guerrero-Muñoz
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
| | - Yessica Ortega
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile,Facultad de Farmacia y Bioanálisis, Universidad de Los Andes, Mérida, Venezuela
| | - Juan Diego Maya
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
| | - Verónica Rojas
- Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile
| | - Wilfredo Quiñones
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | - Paul A. Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Ulrike Kemmerling
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
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Medina L, Jesús-Muñoz G, Castillo C, Liempi A, Ortega Y, Kemmerling U. Toxoplasma gondii infection of human placental explants is mediated by MIR-190B expression. Placenta 2022. [DOI: 10.1016/j.placenta.2022.03.041] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ortega Y, Monge M, Savoini B, Muñoz A, Pérez P. Production and characterization of the CR35FE35V16.5MO6TI7.5 high entropy alloy. Nuclear Materials and Energy 2022. [DOI: 10.1016/j.nme.2022.101148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Muñoz A, Savoini B, Monge M, Ortega Y, Dura O. Fabrication and characterization of Cu reinforced with Y-enriched particles following a novel powder metallurgy route. Nuclear Materials and Energy 2021. [DOI: 10.1016/j.nme.2021.101075] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sullivan J, Bernie H, Ortega Y, Mulhall J. 615 Comparative analysis of the natural history of de novo Peyronie’s Disease versus post-radical prostatectomy Peyronie’s Disease. J Sex Med 2018. [DOI: 10.1016/j.jsxm.2018.04.522] [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: 10/28/2022]
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8
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Miranda E, Ortega Y, Deveci S, Jenkins L, Mulhall J. 196 Device Autoinflation Following Penile Implant Surgery. J Sex Med 2017. [DOI: 10.1016/j.jsxm.2016.12.184] [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: 11/28/2022]
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9
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Miranda E, Ortega Y, Deveci S, Jenkins L, Mulhall J. 156 Device autoinflation following penile implant surgery. J Sex Med 2017. [DOI: 10.1016/j.jsxm.2016.11.103] [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: 11/26/2022]
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10
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Cebriano T, Ortega Y, Hidalgo P, Maestre D, Méndez B, Piqueras J. Study of mechanical resonances of Sb2O3 micro- and nanorods. Nanotechnology 2014; 25:235701. [PMID: 24848514 DOI: 10.1088/0957-4484/25/23/235701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Sb2O3 microrods with orthorhombic phase were grown by an evaporation-deposition method from a pure antimony source and substrate. The incorporation of Cr into the substrate has been found to enhance the growth of thinner rods with high crystalline quality, as is revealed by high resolution transmission electron microscopy (HRTEM). Electric field-induced mechanical resonances of Sb2O3 nanorods were studied by in situ measurements in a scanning electron microscope (SEM). Young's modulus of rods with different lengths and cross-sectional dimensions was calculated from the resonance frequency. The E values for the different rods were in the range of 16-48 GPa. For comparison, Young's moduli of several rods were also measured from the force-displacement curve recorded in an atomic force microscope (AFM). The slight difference between the E values obtained by the resonance and by the AFM techniques is within the accepted experimental error.
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Affiliation(s)
- T Cebriano
- Departamento de Física de Materiales, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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11
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Vargas R, Ortega Y, Bozo V, Andrade M, Minuzzi G, Cornejo P, Fernandez V, Videla LA. Thyroid hormone activates rat liver adenosine 5,-monophosphate-activated protein kinase: relation to CaMKKb, TAK1 and LKB1 expression and energy status. J BIOL REG HOMEOS AG 2013; 27:989-999. [PMID: 24382180] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
AMP-activated protein kinase (AMPK) is a sensor of energy status supporting cellular energy homeostasis that may represent the metabolic basis for 3,3,,5-triiodo-L-thyronine (T3) liver preconditioning. Functionally transient hyperthyroid state induced by T3 (single dose of 0.1 mg/kg) in fed rats led to upregulation of mRNA expression (RT-PCR) and protein phosphorylation (Western blot) of hepatic AMPK at 8 to 36 h after treatment. AMPK Thr 172 phosphorylation induced by T3 is associated with enhanced mRNA expression of the upstream kinases Ca2+ -calmodulin-dependent protein kinase kinase-beta (CaMKKbeta) and transforming growth-factor-beta-activated kinase-1 (TAK1), with increased protein levels of CaMKKbeta and higher TAK1 phosphorylation, without changes in those of the liver kinase B1 (LKB1) signaling pathway. Liver contents of AMP and ADP were augmented by 291 percent and 44 percent by T3 compared to control values (p less than 0.05), respectively, whereas those of ATP decreased by 64% (p less than 0.05), with no significant changes in the total content of adenine nucleotides (AMP + ADP + ATP) at 24 h after T3 administration. Consequently, hepatic ATP/ADP content ratios exhibited 64 percent diminution (p less than 0.05) and those of AMP/ATP increased by 425 percent (p less than 0.05) in T3-treated rats over controls. It is concluded that in vivoT3 administration triggers liver AMPK upregulation in association with significant enhancements in AMPK mRNA expression, AMPK phosphorylation coupled to CaMKKbeta and TAK1 activation, and in AMP/ATP ratios, which may promote enhanced AMPK activity to support T3-induced energy consuming processes such as those of liver preconditioning.
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Affiliation(s)
- R Vargas
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Y Ortega
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - V Bozo
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - M Andrade
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - G Minuzzi
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - P Cornejo
- School of Medical Technology, Faculty of Medicine, Diego Portales University, Santiago, Chile
| | - V Fernandez
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - L A Videla
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
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Ortega Y, Dieker C, Jäger W, Piqueras J, Fernández P. Voids, nanochannels and formation of nanotubes with mobile Sn fillings in Sn doped ZnO nanorods. Nanotechnology 2010; 21:225604. [PMID: 20453289 DOI: 10.1088/0957-4484/21/22/225604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
ZnO nanorods containing different hollow structures have been grown by a thermal evaporation-deposition method with a mixture of ZnS and SnO(2) powders as precursor. Transmission electron microscopy shows rods with rows of voids as well as rods with empty channels along the growth axis. The presence of Sn nanoprecipitates associated with the empty regions indicates, in addition, that these are generated by diffusion processes during growth, probably due to an inhomogeneous distribution of Sn. The mechanism of forming voids and precipitates appears to be based on diffusion processes similar to the Kirkendall effect, which can lead to void formation at interfaces of bulk materials or in core-shell nanostructures. In some cases the nanorods are ZnO tubes partially filled with Sn that has been found to melt and expand by heating the nanotubes under the microscope electron beam. Such metal-semiconductor nanostructures have potential applications as thermal nanosensors or as electrical nanocomponents.
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Affiliation(s)
- Y Ortega
- Microanalysis of Materials, Institute of Materials Science, Christian-Albrechts-University of Kiel, Kiel, Germany
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Ortega Y, Fernández P, Piqueras J. Growth and cathodoluminescence of Eu doped ZnO nanoneedles and branched nanoneedle structures. J Nanosci Nanotechnol 2010; 10:502-507. [PMID: 20352883 DOI: 10.1166/jnn.2010.1586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Rare-earth (RE) ions are widely investigated luminescent centers because their intraionic-4f transitions generate narrow and intense emission lines. In this work Eu doped ZnO nanoneedles have been grown, by a thermal evaporation-deposition method, and structural and luminescence characterization has been carried out. Mixtures of ZnO and Eu2O3 or of ZnS and Eu2O3 powders were used as precursors. Annealing of the compacted powder mixtures leads to the growth of nanoneedles and nanoneedle networks, as well as rods. EDS and CL measurements enable to detect the incorporation of Eu in these structures. The choice of precursor, ZnO-Eu2O3 or ZnS-Eu2O3 influences the morphology as well as the luminescence properties of the obtained nanostructures. In particular, while in the samples obtained from ZnO, the defect green luminescence band is practically absent, the band is present in the ZnO nanoneedles obtained from ZnS. Besides the broad deep level band, a series of well-separated narrow-peaks characteristic of the intrinsic red luminescence of Eu+3 ions are observed in all cases, whose relative intensities vary from one set of samples to the other. The results suggest that the Eu3+ ions have at least, two possible configurations in the ZnO lattice with different symmetry in the nanoneedles.
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Affiliation(s)
- Y Ortega
- Departamento de Física de Materiales, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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14
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Piqueras J, Maestre D, Ortega Y, Cremades A, Fernández P. Cathodoluminescence study of semiconductor oxide micro- and nanostructures grown by vapor deposition. Scanning 2008; 30:354-357. [PMID: 18512700 DOI: 10.1002/sca.20105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Nano- and microstructures of SnO(2), In(2)O(3) and ZnO have been grown during thermal treatment of compacted powders under argon flow. Indium-doped SnO(2) tube-shaped structures with rectangular cross-section are obtained by adding a fraction of In(2)O(3) to the starting SnO(2) powder. In-rich nanoislands were found to grow on some edges of the tubes. ZnO nanostructures doped with Sn or Eu were grown by adding SnO(2) and Eu(2)O(3) powder, respectively, to the ZnO precursor powder. All the samples have been characterized by the emissive and cathodoluminescence (CL) modes of scanning electron microscopy. CL images from SnO(2):In and In(2)O(3):Sn tubes and islands show a higher emission from the Sn-rich structures related to oxygen deficiency. CL of doped ZnO enables to detect the presence of dopant in specific regions or structures. CL appears to be a useful technique to study optical and electronic properties of semiconductor oxide nanostructures.
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Affiliation(s)
- J Piqueras
- Departamento de Física de Materiales, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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Abstract
The effect of a population's location on the landscape on genetic variation has been of interest to population genetics for more than half a century. However, most studies do not consider broadscale biogeography when interpreting genetic data. In this study, we propose an operational definition of a peripheral population, and then explore whether peripheral populations of Canada lynx (Lynx canadensis) have less genetic variation than core populations at nine microsatellite loci. We show that peripheral populations of lynx have fewer mean numbers of alleles per population and lower expected heterozygosity. This is surprising, given the lynx's capacity to move long distances, but can be explained by the fact that peripheral populations often have smaller population sizes, limited opportunities for genetic exchange and may be disproportionately affected by ebbs and flows of species' geographical range.
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Affiliation(s)
- M K Schwartz
- Wildlife Biology Program, University of Montana, Missoula, MT 59812, USA.
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Abstract
Two dogs, one from California and one from Arizona, were found to have aberrant infections caused by filarial nematodes of the genus Onchocerca. In both cases, the parasites are localized in or near the eye. In one case the worm was located in the cornea and was surgically removed. In the second case, a very marked granulomatous reaction was induced in the retrobulbar space, mimicking an abscess. This eye was enucleated. The worms in both instances were female, and were gravid, i.e. contained microfilariae in utero, indicating that a male worm(s) had been present and mating had occurred. The exact identity of the species of Onchocerca responsible cannot be determined, although the features observed are most like Onchocerca lienalis of cattle. These cases represent the fourth and fifth such cases reported from the US, and are especially interesting because of the unusual location of the worms, the small number of recognized cases, and the similarity to a recent zoonotic human infection.
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Affiliation(s)
- M L Eberhard
- Division of Parasitic Diseases, National Center for Infectious Diseases, Public Health Service, US Department of Health and Human Services, Atlanta, GA 30341-3724, USA.
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Gumbo T, Sarbah S, Gangaidzo IT, Ortega Y, Sterling CR, Carville A, Tzipori S, Wiest PM. Intestinal parasites in patients with diarrhea and human immunodeficiency virus infection in Zimbabwe. AIDS 1999; 13:819-21. [PMID: 10357381 DOI: 10.1097/00002030-199905070-00011] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [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: 11/26/2022]
Abstract
OBJECTIVES To determine the prevalence of intestinal parasites and risk factors for infection associated with diarrhea in HIV-infected patients in Harare, Zimbabwe. DESIGN Prospective observational study. METHODS Single stool samples were collected from 88 HIV-infected individuals presenting with diarrhea of greater than 1 week duration. Stools were examined for intestinal parasites using modified acid fast stain, fluorescence- labeled monoclonal antibody for Cryptosporidium parvum, as well as a modified trichrome stain and a PCR-based protocol for Enterocytozoon bieneusi. RESULTS C. parvum was detected in 9% (seven out of 82) of samples evaluated, but no Cyclospora was detected. E. bieneusi was detected in 18% (10 out of 55) of stool by trichrome staining and in 51% (28 out of 55) of stool examined by PCR. Risk factors for E. bieneusi infection were: living in rural areas, consumption of nonpiped water, contact with cow dung and household contact with an individual with diarrhea. CONCLUSION E. bieneusi infection was common in HIV-infected patients with diarrhea in Zimbabwe and may be acquired through person-to-person and fecal-oral transmission.
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Affiliation(s)
- T Gumbo
- Department of Infectious Disease, Cleveland Clinic Foundation, Ohio, USA
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Abstract
Protozoan parasites were the most frequently identified etiologic agents in waterborne disease outbreak from 1991 to 1994. The waterborne parasites Giardia lamblia, Naegleria fowleri, Acanthamoeba spp., Entamoeba histolytica, Cryptosporidium parvum, Cyclospora cayetanesis, Isospora belli, and the microsporidia are reviewed. For each parasite, the review includes history, life cycle, incidence, symptoms, and therapy. Clinical detection methods are compared, and emerging technologies are discussed. Information on the association of these parasites with waterborne outbreaks is reviewed. Current information on protozoan parasites identified as etiological agents in waterborne outbreaks is discussed. Water industry issues related to recent disease outbreaks are examined in the context of water quality testing regulations for G. lamblia and those proposed for C. parvum. The review identifies the limitations of the American Society of Testing and Materials water-testing method for these parasites. An overview of federal regulations affecting the water industry and laboratories that test for water quality is also provided. The article highlights the importance of the clinical laboratory as a frontline defense for the detection of infectious organisms. The review points to the need for clinical laboratories, physicians, and public health personnel to cooperatively plan and assess the challenge of meeting this potential public health threat.
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Affiliation(s)
- M M Marshall
- Department of Veterinary Science, University of Arizona, Tucson 85721, USA.
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Yang YM, Ortega Y, Sterling C, Adam RD. Giardia lamblia trophozoites contain multiple alleles of a variant-specific surface protein gene with 105-base pair tandem repeats. Mol Biochem Parasitol 1994; 68:267-76. [PMID: 7739672 DOI: 10.1016/0166-6851(94)90171-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [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: 01/26/2023]
Abstract
Giardia lamblia trophozoites undergo antigenic variation of a variant-specific surface protein (VSP). All VSPs that have been reported have had high cysteine contents, including numerous copies of a CXXC motif. The first vsp gene described (vspA6; from the cloned line, WBA6), contained 21 copies of a 195 base pair tandem repeat, but other reported VSPs have not contained repeats. In this report, we describe the vsp gene from WBC5, a cloned line derived from WBA6. The vspC5 gene contains short 5' and 3' regions flanking 26 copies of a 105-bp tandem repeat, which comprises 93% of the coding region. In addition to the copy containing 26 repeats, the genome contains other copies of the vspC5 with fewer copies of the repeat. The sequences flanking the repeats are identical, and all copies map to the same location on chromosomal Band 5, suggesting that multiple alleles of the vspC5 gene are present.
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MESH Headings
- Alleles
- Amino Acid Sequence
- Animals
- Antigenic Variation/genetics
- Antigenic Variation/immunology
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Surface/genetics
- Antigens, Surface/immunology
- Base Sequence
- Cloning, Molecular
- DNA, Protozoan/analysis
- Electrophoresis, Gel, Pulsed-Field
- Genes, Protozoan/genetics
- Giardia lamblia/genetics
- Giardia lamblia/immunology
- Molecular Sequence Data
- Polyploidy
- Protozoan Proteins
- Repetitive Sequences, Nucleic Acid
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Affiliation(s)
- Y M Yang
- Department of Medicine, College of Medicine, University of Arizona, Tucson 85724
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