1
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Martínez-Pérez Y, Nequiz-Avendaño M, García-Torres I, Gudiño-Zayas ME, López-Velázquez G, Enríquez-Flores S, Mendoza E, Saavedra E, Pérez-Tamayo R, León-Avila G, Olivos-García A. Rabeprazole inhibits several functions of Entamoeba histolytica related with its virulence. Parasitol Res 2020; 119:3491-3502. [PMID: 32886229 DOI: 10.1007/s00436-020-06868-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [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: 05/18/2020] [Accepted: 08/26/2020] [Indexed: 11/24/2022]
Abstract
Amoebiasis is a human parasitic disease caused by Entamoeba histolytica. The parasite can invade the large intestine and other organs such as liver; resistance to the host tissue oxygen is a condition for parasite invasion and survival. Thioredoxin reductase of E. histolytica (EhTrxR) is a critical enzyme mainly involved in maintaining reduced the redox system and detoxifying the intracellular oxygen; therefore, it is necessary for E. histolytica survival under both aerobic in vitro and in vivo conditions. In the present work, it is reported that rabeprazole (Rb), a drug widely used to treat heartburn, was able to inhibit the EhTrxR recombinant enzyme. Moreover, Rb affected amoebic proliferation and several functions required for parasite virulence such as cytotoxicity, oxygen reduction to hydrogen peroxide, erythrophagocytosis, proteolysis, and oxygen and complement resistances. In addition, amoebic pre-incubation with sublethal Rb concentration (600 μM) promoted amoebic death during early liver infection in hamsters. Despite the high Rb concentration used to inhibit amoebic virulence, the wide E. histolytica pathogenic-related functions affected by Rb strongly suggest that its molecular structure can be used as scaffold to design new antiamoebic compounds with lower IC50 values.
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Affiliation(s)
- Yoalli Martínez-Pérez
- Departamento de Zoología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Carpio y Plan de Ayala S/N. Col. Casco de Santo Tomás, Ciudad de México, 11340, México. .,Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México.
| | - Mario Nequiz-Avendaño
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México
| | - Itzhel García-Torres
- Grupo de Investigación en Biomoléculas y Salud Infantil, Laboratorio de EIMyT, Instituto Nacional de Pediatría, Ciudad de México, 04530, México
| | - Marco E Gudiño-Zayas
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México
| | - Gabriel López-Velázquez
- Grupo de Investigación en Biomoléculas y Salud Infantil, Laboratorio de EIMyT, Instituto Nacional de Pediatría, Ciudad de México, 04530, México
| | - Sergio Enríquez-Flores
- Grupo de Investigación en Biomoléculas y Salud Infantil, Laboratorio de EIMyT, Instituto Nacional de Pediatría, Ciudad de México, 04530, México
| | - Edith Mendoza
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México
| | - Emma Saavedra
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Ciudad de México, 14080, México
| | - Ruy Pérez-Tamayo
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México
| | - Gloria León-Avila
- Departamento de Zoología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Carpio y Plan de Ayala S/N. Col. Casco de Santo Tomás, Ciudad de México, 11340, México
| | - Alfonso Olivos-García
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México
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2
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Santos F, Marcial-Quino J, Gómez-Manzo S, Enríquez-Flores S, Nequiz-Avendaño M, Cortes A, De la Luz León-Avila G, Saavedra E, Pérez-Tamayo R, Olivos-García A. Functional characterization and subcellular distribution of two recombinant cytosolic HSP70 isoforms from Entamoeba histolytica under normal and stress conditions. Parasitol Res 2020; 119:1337-1351. [PMID: 32056023 DOI: 10.1007/s00436-020-06621-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 07/25/2019] [Accepted: 02/05/2020] [Indexed: 11/26/2022]
Abstract
Amoebiasis is a human intestinal disease caused by the parasite Entamoeba histolytica. It has been previously demonstrated that E. histolytica heat shock protein 70 (EhHSP70) plays an important role in amoebic pathogenicity by protecting the parasite from the dangerous effects of oxidative and nitrosative stresses. Despite its relevance, this protein has not yet been characterized. In this study, the EhHSP70 genes were cloned, and the two recombinant EhHSP70 proteins were expressed, purifying and biochemically characterized. Additionally, after being subjected to some host stressors, the intracellular distribution of the proteins in the parasite was documented. Two amoebic HSP70 isoforms, EhHSP70-A and EhHSP70-B, with 637 and 656 amino acids, respectively, were identified. Kinetic parameters of ATP hydrolysis showed low rates, which were in accordance with those of the HSP70 family members. Circular dichroism analysis showed differences in their secondary structures but similarities in their thermal stability. Immunocytochemistry in trophozoites detected EhHSP70 in the nuclei and cytoplasm as well as a slight overexpression when the parasites were subjected to oxidants and heat. The structural differences of amoebic HSP70s with their human counterparts may be used to design specific inhibitors to treat human amoebiasis.
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Affiliation(s)
- Fabiola Santos
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, México, Mexico
- Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340, México, Mexico
| | - Jaime Marcial-Quino
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaria de Salud, 04530, México, Mexico
| | - Saúl Gómez-Manzo
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaria de Salud, 04530, México, Mexico
| | - Sergio Enríquez-Flores
- Grupo de Investigación en Biomoléculas y Salud Infantil, Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaria de Salud, 04530, México, Mexico
| | - Mario Nequiz-Avendaño
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, México, Mexico
| | - Azucena Cortes
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, México, Mexico
| | - Gloria De la Luz León-Avila
- Departamento de Zoología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340, México, Mexico
| | - Emma Saavedra
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Secretaría de Salud, 14080, México, Mexico
| | - Ruy Pérez-Tamayo
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, México, Mexico
| | - Alfonso Olivos-García
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510, México, Mexico.
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3
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Vega-Galaviz D, Vecchyo-Tenorio GD, Alcántara-Suárez R, Méndez-García LA, Sánchez-Del Real AL, Villalobos-Molina R, Fragoso JM, León-Cabrera S, Ostoa-Saloma P, Pérez-Tamayo R, Escobedo G. M2 macrophage immunotherapy abolishes glucose intolerance by increasing IL-10 expression and AKT activation. Immunotherapy 2020; 12:9-24. [PMID: 31914828 DOI: 10.2217/imt-2019-0080] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aim: Glucose intolerance associates with M1/M2 macrophage unbalance. We thus wanted to examine the effect of M2 macrophage administration on mouse model of glucose intolerance. Materials & methods: C57BL/6 mice fed a high-fat diet (HFD) for 12 weeks and then received thrice 20 mg/kg streptozotocin (HFD-GI). Bone marrow-derived stem cells were collected from donor mice and differentiated/activated into M2 macrophages for intraperitoneal administration into HFD-GI mice. Results: M2 macrophage treatment abolished glucose intolerance independently of obesity. M2 macrophage administration increased IL-10 in visceral adipose tissue and serum, but showed no effect on serum insulin. While nitric oxide synthase-2 and arginase-1 remained unaltered, M2 macrophage treatment restored AKT phosphorylation in visceral adipose tissue. Conclusion: M2 macrophage treatment abolishes glucose intolerance by increasing IL-10 and phosphorylated AKT.
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Affiliation(s)
- Diana Vega-Galaviz
- Laboratory for Proteomics & Metabolomics, Research Division, General Hospital of Mexico 'Dr. Eduardo Liceaga', 06720 Mexico City, Mexico
| | - Georgina Del Vecchyo-Tenorio
- Laboratory for Proteomics & Metabolomics, Research Division, General Hospital of Mexico 'Dr. Eduardo Liceaga', 06720 Mexico City, Mexico.,Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Raúl Alcántara-Suárez
- Laboratory for Proteomics & Metabolomics, Research Division, General Hospital of Mexico 'Dr. Eduardo Liceaga', 06720 Mexico City, Mexico
| | - Lucia A Méndez-García
- Laboratory for Proteomics & Metabolomics, Research Division, General Hospital of Mexico 'Dr. Eduardo Liceaga', 06720 Mexico City, Mexico
| | - Ana L Sánchez-Del Real
- Laboratory for Proteomics & Metabolomics, Research Division, General Hospital of Mexico 'Dr. Eduardo Liceaga', 06720 Mexico City, Mexico
| | - Rafael Villalobos-Molina
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Mexico.,Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - José M Fragoso
- Departamento de Biología Molecular, Instituto Nacional de Cardiología 'Ignacio Chávez', Mexico City, Mexico
| | - Sonia León-Cabrera
- Carrera de Médico Cirujano, Unidad de Biomedicina, Facultad de Estudios Superiores-Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala 54090, Mexico
| | - Pedro Ostoa-Saloma
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico
| | - Ruy Pérez-Tamayo
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Galileo Escobedo
- Laboratory for Proteomics & Metabolomics, Research Division, General Hospital of Mexico 'Dr. Eduardo Liceaga', 06720 Mexico City, Mexico
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Paredes-Turrubiarte G, González-Chávez A, Pérez-Tamayo R, Salazar-Vázquez BY, Hernández VS, Garibay-Nieto N, Fragoso JM, Escobedo G. Severity of non-alcoholic fatty liver disease is associated with high systemic levels of tumor necrosis factor alpha and low serum interleukin 10 in morbidly obese patients. Clin Exp Med 2015; 16:193-202. [PMID: 25894568 DOI: 10.1007/s10238-015-0347-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 04/02/2015] [Indexed: 02/06/2023]
Abstract
Morbid obesity has been shown to increase the risk to develop hepatic steatosis, also referred to as non-alcoholic fatty liver disease (NAFLD). Emerging evidence suggests that the severity of NAFLD may associate with increased serum levels of inflammatory markers as well as decreased concentration of mediators with anti-inflammatory actions, such as tumor necrosis factor alpha (TNF-α) and interleukin (IL) 10, respectively. We thus examined the serum levels of TNF-α and IL-10 in 102 morbidly obese women and men (body mass index > 40 kg/m(2)), exhibiting different grades of NAFLD. Blood glucose, glycated hemoglobin, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), total cholesterol, triglycerides, high- and low-density lipoproteins, parameters of liver function, TNF-α, and IL-10 were measured in each subject. The stage of NAFLD was estimated by abdominal ultrasound imaging. In comparison with morbidly obese subjects without steatosis, morbidly obese patients with NAFLD showed increased age (39.23 ± 9.80 years), HOMA-IR (6.74 ± 1.62), total cholesterol (219.7 ± 9.58 mg/dl), aspartate aminotransferase (36.25 ± 3.24 UI/l), gamma-glutamyl transpeptidase (37.12 ± 3.41 UI/l), and TNF-α (37.41 ± 1.72 pg/ml) as well as decreased serum levels of IL-10 (61.05 ± 2.43 pg/ml). Interestingly, the systemic levels of TNF-α increased, while IL-10 decreased in accordance with the severity of NAFLD, which supports a role for systemic inflammatory mediators in promoting steatosis progression. Further clinical prospective studies need to be addressed to elucidate the role of TNF-α and IL-10 in the development of NAFLD while also establishing their clinical utility in the assessment of morbidly obese patients at higher risk to develop severe steatosis.
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Affiliation(s)
| | - Antonio González-Chávez
- Department of Internal Medicine, General Hospital of Mexico "Dr. Eduardo Liceaga", 06720, Mexico, D.F., Mexico.
| | - Ruy Pérez-Tamayo
- Unit of Experimental Medicine, School of Medicine, National University of Mexico, General Hospital of Mexico "Dr. Eduardo Liceaga", 06720, Mexico, D.F., Mexico
| | - Beatriz Y Salazar-Vázquez
- Unit of Experimental Medicine, School of Medicine, National University of Mexico, General Hospital of Mexico "Dr. Eduardo Liceaga", 06720, Mexico, D.F., Mexico
| | - Vito S Hernández
- Departament of Physiology, School of Medicine, National University of Mexico, 04510, Mexico, D.F., Mexico
| | - Nayeli Garibay-Nieto
- Department of Human Genetics, General Hospital of Mexico "Dr. Eduardo Liceaga", 06720, Mexico, D.F., Mexico
| | - José Manuel Fragoso
- Department of Molecular Biology, National Institute of Cardiology "Ignacio Chávez", 14080, Mexico, D.F., Mexico
| | - Galileo Escobedo
- Unit of Experimental Medicine, School of Medicine, National University of Mexico, General Hospital of Mexico "Dr. Eduardo Liceaga", 06720, Mexico, D.F., Mexico.
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5
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Santos F, Nequiz M, Hernández-Cuevas NA, Hernández K, Pineda E, Encalada R, Guillén N, Luis-García E, Saralegui A, Saavedra E, Pérez-Tamayo R, Olivos-García A. Maintenance of intracellular hypoxia and adequate heat shock response are essential requirements for pathogenicity and virulence ofEntamoeba histolytica. Cell Microbiol 2015; 17:1037-51. [DOI: 10.1111/cmi.12419] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 01/05/2015] [Accepted: 01/16/2015] [Indexed: 01/16/2023]
Affiliation(s)
- Fabiola Santos
- Departamento de Medicina Experimental, Facultad de Medicina; Universidad Nacional Autónoma de México; Mexico D.F. 04510 Mexico
- Escuela Nacional de Ciencias Biológicas; Instituto Politécnico Nacional; México D.F. 11340 Mexico
| | - Mario Nequiz
- Departamento de Medicina Experimental, Facultad de Medicina; Universidad Nacional Autónoma de México; Mexico D.F. 04510 Mexico
| | | | - Kahory Hernández
- Departamento de Medicina Experimental, Facultad de Medicina; Universidad Nacional Autónoma de México; Mexico D.F. 04510 Mexico
| | - Erika Pineda
- Departamento de Bioquímica; Instituto Nacional de Cardiología Ignacio Chávez; Mexico D.F. 14080 Mexico
| | - Rusely Encalada
- Departamento de Bioquímica; Instituto Nacional de Cardiología Ignacio Chávez; Mexico D.F. 14080 Mexico
| | - Nancy Guillén
- Unité Biologie Cellulaire du Parasitisme; Institut Pasteur; Paris F-75015 France
- INSERM, U786; Paris F-75015 France
| | - Erika Luis-García
- Departamento de Medicina Experimental, Facultad de Medicina; Universidad Nacional Autónoma de México; Mexico D.F. 04510 Mexico
| | - Andrés Saralegui
- Laboratorio Nacional de Microscopía Avanzada, Instituto de Biotecnología; Universidad Nacional Autónoma de México; Cuernavaca Morelos 62250 Mexico
| | - Emma Saavedra
- Departamento de Bioquímica; Instituto Nacional de Cardiología Ignacio Chávez; Mexico D.F. 14080 Mexico
| | - Ruy Pérez-Tamayo
- Departamento de Medicina Experimental, Facultad de Medicina; Universidad Nacional Autónoma de México; Mexico D.F. 04510 Mexico
| | - Alfonso Olivos-García
- Departamento de Medicina Experimental, Facultad de Medicina; Universidad Nacional Autónoma de México; Mexico D.F. 04510 Mexico
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6
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Pacheco-Tena C, Pérez-Tamayo R, Pineda C, González-Chávez SA, Quiñonez-Flores C, Ugalde Vitelly A, Inman RD, Aubin JE, Vázquez-Mellado J, Burgos-Vargas R. Bone Lineage Proteins in the Entheses of the Midfoot in Patients with Spondyloarthritis. J Rheumatol 2014; 42:630-7. [DOI: 10.3899/jrheum.140218] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2014] [Indexed: 02/02/2023]
Abstract
Objective.Patients with juvenile-onset spondyloarthritis (SpA) may develop ankylosis of the midfoot resembling the spinal changes seen in patients with ankylosing spondylitis (AS). The study of the histopathology of the feet of patients with tarsitis could help us understand the pathogenesis of bone formation in affected structures in the SpA. The objective of our study was to describe the histopathologic characteristics of the midfoot in patients with tarsitis associated with SpA.Methods.We obtained synovial sheaths, entheses, and bone samples from 20 patients with SpA with midfoot pain/tenderness and swelling. Tissue samples underwent H&E staining; immunohistochemistry for CD3, CD4, CD8, CD68, and CD20 cell identification; and immunofluorescence for bone lineage proteins, including osteocalcin, osteopontin, parathyroid hormone-related protein, bone sialoprotein, and alkaline phosphatase.Results.Slight edema and hyalinization were found in some tendon sheaths, and few inflammatory cells were detected in the entheses. In bones, we found some changes suggesting osteoproliferation, including endochondral and intramembranous ossification, but no inflammatory cells. In entheses showing bone proliferation, we detected osteocalcin and osteopontin in cells with a fibroblast-mesenchymal phenotype, suggesting the induction of entheseal cells toward an osteoblast phenotype.Conclusion.Osteoproliferation and abnormal expression of bone lineage proteins, but no inflammatory infiltration, characterize midfoot involvement in patients with SpA. In this sense, tarsitis (or ankylosing tarsitis) resembles the involvement of the spine in patients with AS. Ossification may be in part explained by the differentiation of mesenchymal entheseal cells toward the osteoblastic lineage.
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7
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Salazar Vázquez BY, Salazar Vázquez MA, Chávez-Negrete A, Escobedo G, Cabrales P, Subramaniam S, Intaglietta M, Pérez-Tamayo R. Influence of serological factors and BMI on the blood pressure/hematocrit association in healthy young men and women. Vasc Health Risk Manag 2014; 10:271-7. [PMID: 24851053 PMCID: PMC4018417 DOI: 10.2147/vhrm.s60130] [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] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The association between mean arterial blood pressure (MAP) and hematocrit (Hct) as a surrogate for blood viscosity was investigated in a young (average 20.0±2.3 years), healthy population of 174 men and 442 women. Health status was assessed by clinical examination and serological evaluation. Individuals with severe anemia or hemoconcentration, prior traumas or major surgical intervention, smokers, and pregnant or lactating women were excluded from the study. The MAP/Hct association was positive and significant (P=0.04) for women and negative, albeit not significantly so, for men. The MAP/Hct association was also evaluated in subgroups of the same population with a progressive step-by-step exclusion of: individuals with cholesterol >200 mg/dL; triglycerides >200 mg/dL; body mass index >25 kg/m(2); and glucose >100 mg/dL. This consecutively reduced the strength of the positive MAP/Hct association in women, which became negative - although not significantly so - when all anomalously high factors were excluded. The same trend was found in men. Our study indicates that previously reported positive trends in the relationship between the MAP and Hct in the population are not present in a young, healthy population of men or women that excludes individuals with the confounding factors of above normal serological values and BMI.
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Affiliation(s)
- Beatriz Y Salazar Vázquez
- Faculty of Medicine, Universidad Juárez del Estado de Durango, Victoria de Durango, Dgo, Mexico ; Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico ; Department of Bioengineering, University of California, San Diego, CA, USA
| | - Miguel A Salazar Vázquez
- Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico ; Department of Pediatrics, Hospital General de Zona No. 1, Instituto Mexicano del Seguro Social, Durango, Dgo, Mexico
| | | | - Galileo Escobedo
- Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico
| | - Pedro Cabrales
- Department of Bioengineering, University of California, San Diego, CA, USA
| | | | - Marcos Intaglietta
- Department of Bioengineering, University of California, San Diego, CA, USA
| | - Ruy Pérez-Tamayo
- Department of Experimental Medicine, Faculty of Medicine, Universidad Nacional Autónoma de México, Hospital General de México Dr Eduardo Liceaga, México City, Mexico
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8
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López-Vancell R, Arreguín Espinosa R, González-Canto A, Néquiz Avendaño M, García de León MC, Olivos-García A, López-Vancell D, Pérez-Tamayo R. Entamoeba histolytica: Expression and localization of Gal/GalNAc lectin in virulent and non-virulent variants from HM1:IMSS strain. Exp Parasitol 2010; 125:244-50. [PMID: 20138867 DOI: 10.1016/j.exppara.2010.01.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 01/25/2010] [Accepted: 01/27/2010] [Indexed: 11/29/2022]
MESH Headings
- Animals
- Antibodies, Protozoan/immunology
- Antibody Specificity
- Antigens, Tumor-Associated, Carbohydrate/immunology
- Antigens, Tumor-Associated, Carbohydrate/isolation & purification
- Antigens, Tumor-Associated, Carbohydrate/metabolism
- Blotting, Western
- Cricetinae
- Densitometry
- Electrophoresis, Polyacrylamide Gel
- Entamoeba histolytica/immunology
- Entamoeba histolytica/metabolism
- Entamoeba histolytica/pathogenicity
- Immunohistochemistry
- Lectins/immunology
- Lectins/isolation & purification
- Lectins/metabolism
- Liver Abscess, Amebic/immunology
- Liver Abscess, Amebic/parasitology
- Male
- Rabbits
- Trophozoites/immunology
- Trophozoites/metabolism
- Virulence
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Affiliation(s)
- R López-Vancell
- Medicine Faculty, National Autonomus University of Mexico, General Hospital of Mexico, Mexico City, Mexico.
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9
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Olivos-García A, Saavedra E, Ramos-Martínez E, Nequiz M, Pérez-Tamayo R. Molecular nature of virulence in Entamoeba histolytica. Infect Genet Evol 2009; 9:1033-7. [PMID: 19376272 DOI: 10.1016/j.meegid.2009.04.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 03/30/2009] [Accepted: 04/03/2009] [Indexed: 01/07/2023]
Abstract
For many years virulence of pathogenic Entamoeba histolytica has been attributed to the capacity of the parasite to destroy tissues through the expression and/or secretion of various molecules. Such view is supported mainly by in vitro experimentation, whereas data obtained by using animal models of the disease have clearly demonstrated that the host's inflammatory response is primarily responsible for tissue damage. This review analyzes the content and/or activity of some of the presumed toxic amebic molecules present in amebic strains with different degrees of virulence compared to various parasite in vitro functions that are supposed to correlate with in vivo virulence. The analysis suggests that amebic virulence is primarily determined by the parasite's capacity to adapt and survive the aerobic conditions present in animal tissues. This initial episode in the host-parasite relationship is an absolute requirement for the further development of tissue lesions, which result from the concerted action of many molecules derived from both, the host and the parasite.
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Affiliation(s)
- Alfonso Olivos-García
- Departamento de Medicina Experimental Facultad de Medicina, Universidad Nacional Autónoma de México, México DF, Mexico.
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10
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Ramos-Martínez E, Olivos-García A, Saavedra E, Nequiz M, Sánchez EC, Tello E, El-Hafidi M, Saralegui A, Pineda E, Delgado J, Montfort I, Pérez-Tamayo R. Entamoeba histolytica: oxygen resistance and virulence. Int J Parasitol 2008; 39:693-702. [PMID: 19073188 DOI: 10.1016/j.ijpara.2008.11.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 11/07/2008] [Accepted: 11/10/2008] [Indexed: 11/25/2022]
Abstract
Entamoeba histolytica virulence has been attributed to several amoebic molecules such as adhesins, amoebapores and cysteine proteinases, but supporting evidence is either partial or indirect. In this work we compared several in vitro and in vivo features of both virulent E. histolytica (vEh) and non-virulent E. histolytica (nvEh) axenic HM-1 IMSS strains, such as complement resistance, proteinase activity, haemolytic, phagocytic and cytotoxic capacities, survival in mice caecum, and susceptibility to O(2). The only difference observed was a higher in vitro susceptibility of nvEh to O(2). The molecular mechanism of that difference was analyzed in both groups of amoebae after high O(2) exposure. vEh O(2) resistance correlated with: (i) higher O(2) reduction (O(2)(-) and H(2)O(2) production); (ii) increased H(2)O(2) resistance and thiol peroxidase activity, and (iii) reversible pyruvate: ferredoxin oxidoreductase (PFOR) inhibition. Despite the high level of carbonylated proteins in nvEh after O(2) exposure, membrane oxidation by reactive oxygen species was not observed. These results suggest that the virulent phenotype of E. histolytica is related to the greater ability to reduce O(2) and H(2)O(2) as well as PFOR reactivation, whereas nvEh undergoes irreversible PFOR inhibition resulting in metabolic failure and amoebic death.
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Affiliation(s)
- Espiridión Ramos-Martínez
- Departamento de Medicina Experimental Facultad de Medicina, Dr. Balmis 148 Colonia Doctores, Universidad Nacional Autónoma de México, 06720 México DF, CP 04510, Mexico
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11
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González A, Monterrubio D, Nequiz M, López R, Olivos A, de Léon CG, Tello E, Salaiza N, Ramos E, Gudiño M, Montfort I, Pérez-Tamayo R. Localization ofEntamoeba histolyticaAmebopore in Amebic Liver Abscesses in Hamsters. Ann N Y Acad Sci 2008; 1149:375-9. [DOI: 10.1196/annals.1428.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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12
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Sáenz B, Ramírez J, Aluja A, Escobar A, Fragoso G, Morales J, Pérez-Tamayo R, Rosetti F, Larralde C, Sciutto E, Fleury A. Human and porcine neurocysticercosis: differences in the distribution and developmental stages of cysticerci. Trop Med Int Health 2008; 13:697-702. [DOI: 10.1111/j.1365-3156.2008.02059.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Olivos-García A, Carrero JC, Ramos E, Nequiz M, Tello E, Montfort I, Pérez-Tamayo R. Late experimental amebic liver abscess in hamster is inhibited by cyclosporine and N-acetylcysteine. Exp Mol Pathol 2007; 82:310-5. [PMID: 17362925 DOI: 10.1016/j.yexmp.2006.09.005] [Citation(s) in RCA: 18] [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] [Received: 06/20/2006] [Revised: 09/22/2006] [Accepted: 09/27/2006] [Indexed: 11/25/2022]
Abstract
During early experimental amebic liver abscess in hamsters (EALAH), acute inflammation is primarily responsible for tissue damage. However, during the late stages of this process, the relative contribution to tissue destruction of both parasite factors and host response is unknown. In the present work, the role of the cellular immune response in tissue damage during EALAH is explored by using the immunosuppressor drug cyclosporine A (CsA). CsA treatment inhibits tissue damage after 72 h (but not at 24 h). Also, many well-preserved parasite clusters with minimal or no leukocyte influx and with minimal or no tissue destruction characterize the late stage of the process (7 days). The same results are observed with the immunosuppressor tacrolimus, but not with sirolimus; the latter drug does not cause immunosuppression in hamsters. On the other hand, similar results are observed with the antioxidant and anti-inflammatory N-acetylcysteine, with minimal immunosuppression in hamsters. These results suggest that, as in the early EALAH (24 h), during the late stages of the process (7 days), inflammation is also primarily responsible for tissue damage. However, lysosomal and cationic proteins are responsible for the early lesions, whereas reactive oxygen and nitrogen species are primarily involved in late stages.
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Affiliation(s)
- A Olivos-García
- Department of Experimental Medicine, Medical School, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, D.F. 04510, México
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14
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Lisker R, Pérez-Tamayo R. [Conscientious objectors among physicians]. GAC MED MEX 2006; 142 Suppl 2:13-15. [PMID: 19031675] [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: 05/27/2023] Open
Abstract
Conscientious objection refers to the possibility that an individual decides not to comply with a legal mandate because of his or hers convictions, which is accepted by some political constitutions. The classical example is to refuse participation in obligatory military service for personal reasons of conscience, but in the present paper we refer to its use in medical practice utilizing three examples: euthanasia, abortion and the refusal to prescribe emergency contraception. We conclude that in all situations patients rights supersedes conscientious objection.
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Affiliation(s)
- Rubén Lisker
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México D F, México.
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15
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Pérez-Tamayo R, Montfort I, García AO, Ramos E, Ostria CB. Pathogenesis of Acute Experimental Liver Amebiasis. Arch Med Res 2006; 37:203-9. [PMID: 16380320 DOI: 10.1016/j.arcmed.2005.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Accepted: 10/21/2005] [Indexed: 10/25/2022]
Abstract
Classical descriptions of the pathology of amebiasis portray the parasite as the cause of tissue damage and destruction, and in recent years a number of amebic molecules have been identified as virulence factors. In this review we describe a series of experiments that suggest a more complex host-parasite relation, at least during the early stages of acute experimental amebic liver abscess in hamsters. The problems of extrapolating experiments in vitro to explain observations in vivo are discussed. The role of amebic cysteine proteases is examined and evidence presented to suggest that they are primarily related not to tissue damage but to amebic survival, which is required for the progression of the lesion. Inflammation is shown to be not only the major cause of tissue damage but also an absolute requirement for amebic survival in the liver, whereas complement and ischemia are not involved in the disappearance of the parasite in the absence of inflammation.
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Affiliation(s)
- Ruy Pérez-Tamayo
- Department of Experimental Medicine, National Autonomous University Medical School, Mexico City, Mexico.
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16
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Garcíade León MDC, Montfort I, Tello Montes E, López Vancell R, Olivos García A, González Canto A, Nequiz-Avendaño M, Pérez-Tamayo R. Hepatocyte production of modulators of extracellular liver matrix in normal and cirrhotic rat liver. Exp Mol Pathol 2005; 80:97-108. [PMID: 16332368 DOI: 10.1016/j.yexmp.2005.03.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2005] [Accepted: 03/28/2005] [Indexed: 01/18/2023]
Abstract
In the present study, we found collagenolytic and gelatinolytic activity in the supernatants of hepatocyte cultures from rats with experimental CCl(4)-induced liver cirrhosis, in levels significantly higher than in comparable supernatants of hepatocyte cultures from normal rats. In addition, we clearly detected the messenger ribonucleic acids (mRNA) of four matrix metalloproteinases (MMP-2, MMP-3, MMP-10, and MMP-13) and of two tissue inhibitors of matrix metalloproteinases (TIMP-1 and TIMP-2) in hepatocytes from both normal and cirrhotic rats by RT-PCR and by in situ hybridization. Finally, we demonstrated MMP-2, MMP-3, and MMP-13 and TIMP-1 and TIMP-2 proteins in the same hepatocyte preparations by immunostaining. We conclude that rat hepatocytes produce the major enzymes and inhibitors involved in liver ECM modulation and therefore suggests that they might participate actively in the pathophysiology of liver cirrhosis in rats.
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Affiliation(s)
- María del Carmen Garcíade León
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, y Hospital General, de México, D.F. 06720, México
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17
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Pérez-Tamayo R. [Medical ethics, health and social protection. Miguel E. Bustamante Magisterial Lecture]. Salud Publica Mex 2005; 47:245-51. [PMID: 16104468 DOI: 10.1590/s0036-36342005000300009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Ruy Pérez-Tamayo
- Universidad Nacional Autónoma de México, Miembro de El Colegio Nacional y de la Academia Mexicana de la Lengua
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18
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Olivos A, Ramos E, Nequiz M, Barba C, Tello E, Castañón G, González A, Martínez RD, Montfort I, Pérez-Tamayo R. Entamoeba histolytica: Mechanism of decrease of virulence of axenic cultures maintained for prolonged periods. Exp Parasitol 2005; 110:309-12. [PMID: 15955329 DOI: 10.1016/j.exppara.2005.03.020] [Citation(s) in RCA: 21] [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] [Received: 01/12/2005] [Revised: 03/04/2005] [Accepted: 03/05/2005] [Indexed: 10/25/2022]
Abstract
Intraportal injection of non-virulent E. histolytica (derived from prolonged axenic culture of virulent E. histolytica) strain HM1-IMSS in normal hamsters results in no liver lesions and disappearance of the parasites 48-72 h after injection. Viability of non-virulent E. histolytica after 2 h of in vitro incubation in either fresh or decomplemented hamster serum is the same as control virulent E. histolytica (50-90%). In hamsters made leukopenic, or both leukopenic+hypocomplementemic, or hypocomplementemic+sephadex microspheres (to produce focal liver ischemia) intraportally injected non-virulent E. histolytica cause no lesions and disappear after 24 h. In addition, neither hypocomplementemia nor immunosuppression with cyclosporin A prolonged the survival of non-virulent E. histolytica. Methyl prednisolone treatment of hamsters resulted in survival of large numbers of non-virulent E. histolytica in the liver, with little inflammation and minimal tissue damage, for up to 7 days. Inflammatory cells (macrophages) would appear to be chiefly responsible for elimination of non-virulent E. histolytica. Parallel experiments with E. dispar suggest a different mechanism for its non-pathogenicity.
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Affiliation(s)
- Alfonso Olivos
- Department of Experimental Medicine, National Autonomous University of México Medical School, Mexico.
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19
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Pérez-Tamayo R. [The law, medical ethics, and transplants]. Rev Invest Clin 2005; 57:170-6. [PMID: 16524056] [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: 05/07/2023]
Abstract
A discussion of four aspects of the legislation and of the medical ethics of the transplants is presented: the concept of death, the donation of organs, the selection of receivers and the future of the therapeutic transplants. The prominent paragraphs of the General Law of Health of the country about cerebral death, the two legal forms and organs donors' ethics, the criteria and more frequent problems for the selection of receivers, and the character of medical technology of transition of the therapeutic transplants are included.
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Affiliation(s)
- Ruy Pérez-Tamayo
- Departamento de Medicina Experimental, Facultad de Medicina de la UNAM, México, DF
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20
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Olivos-García A, Tello E, Nequiz-Avendaño M, González-Canto A, López-Vancell R, García de León MC, Montfort I, Pérez-Tamayo R. Cysteine proteinase activity is required for survival of the parasite in experimental acute amoebic liver abscesses in hamsters. Parasitology 2004; 129:19-25. [PMID: 15267108 DOI: 10.1017/s0031182004005116] [Citation(s) in RCA: 21] [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: 11/07/2022]
Abstract
Axenic trophozoites of Entamoeba histolytica strain HM1-IMSS grown in vitro in the presence of E-64, a potent irreversible inhibitor of cysteine proteinases, preserved their viability, their rate of replication, their resistance to complement, their haemolytic capacity and their ability to destroy target cells, despite complete inhibition of total cysteine proteinase activity. On the other hand, their erythrophagocytic capacity and their ability to decrease TER of MDCK cells was partially decreased. The same trophozoites injected into the portal vein of hamsters receiving a maintaining dose of E-64 failed to cause tissue damage and were rapidly eliminated. Our results suggest that amoebic cysteine proteinase activity is not required for amoebic functions in in vitro conditions, but that it becomes necessary for survival of trophozoites in in vivo conditions, whatever other role (if any) it may play in the parasite's virulence.
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Affiliation(s)
- A Olivos-García
- Department of Experimental Medicine, National Autonomous University of Mexico Medical School, México City, México
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21
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Olivos-García A, Nequiz-Avendaño M, Tello E, Martínez RD, González-Canto A, López-Vancell R, García de León MC, Montfort I, Pérez-Tamayo R. Inflammation, complement, ischemia and amoebic survival in acute experimental amoebic liver abscesses in hamsters. Exp Mol Pathol 2004; 77:66-71. [PMID: 15215052 DOI: 10.1016/j.yexmp.2003.09.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2003] [Indexed: 10/26/2022]
Abstract
We have examined the role of inflammatory cells, ischemia and serum complement on the development of acute experimental amoebic liver abscess in hamsters (AEALAH). In hamsters made leukopenic by whole body radiation (800 rad) and daily intraperitoneal glycogen injections, the absence of inflammatory cells and liver tissue damage surrounding the parasites resulted in their rapid (24 h) disappearance from the liver, which showed no lesions. Focal liver ischemia, always present in control AEALAH with inflammation and tissue destruction, was reproduced in radiated hamsters by injection of amoebae mixed with Superdex microspheres, but again in the absence of inflammation, amoebae caused no liver damage and disappeared in 24 h. In hamsters made hypocomplementemic by injection of purified cobra venom factor (CVF), amoebae caused AEALA indistinguishable from controls, but in leukopenic + hypocomplementemic hamsters, amoebae were unable to produce lesions and disappeared from the liver in 48 h. We conclude that inflammation and tissue damage are required for the survival of amoebae in AEALAH and for the progression of the experimental disease.
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Affiliation(s)
- A Olivos-García
- Department of Experimental Medicine, National University of México Medical School, Ciudad Universitaria México D.F. 04510, Mexico
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22
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Pérez-Tamayo R. [Biomedical investigation in Mexico]. GAC MED MEX 2004; 140 Suppl 1:S37-41. [PMID: 15646144] [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: 05/01/2023] Open
Abstract
Biomedical research as a professional specialty developed in the Western World in the following four stages: 1) primitive medicine based on magico-religious concepts; 2) hippocratic medicine (500 AD), which renounced supernatural ideas on disease; 3) scientific medicine (1543), which eschewed tradition and authority, and 4) finally in 1813, the first full-time professional biomedical investigator Claude Bernard was appointed in France. Notheless, the first full-time professional biomedical investigator in Mexico did not appear until 1939, and the number is still growing despite present restrictions to investigator growth and development.
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Affiliation(s)
- Ruy Pérez-Tamayo
- Medicina Experimental 2do. Piso, Hospital General de México, Dr. Balmis No. 148, Col. Doctores CP 06720 México, DF
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23
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Olivos-García A, González-Canto A, López-Vancell R, García de León MDC, Tello E, Nequiz-Avendaño M, Montfort I, Pérez-Tamayo R. Amebic cysteine proteinase 2 (EhCP2) plays either a minor or no role in tissue damage in acute experimental amebic liver abscess in hamsters. Parasitol Res 2003; 90:212-20. [PMID: 12783310 DOI: 10.1007/s00436-002-0763-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2002] [Accepted: 09/05/2002] [Indexed: 10/24/2022]
Abstract
Amebic cysteine protease 2 (EhCP2) was purified from ethyl ether extracts of axenically grown trophozoites of Entamoeba histolytica strain HM1-IMSS. The purification procedure involved molecular filtration and electroelution. Sequence analysis of the purified product revealed EhCP2 and ubiquitin(s). Electrophoretic migration patterns, isoelectric point determination and Western blot studies failed to reveal other EhCP molecules. Polyclonal antibodies against the purified EhCP2 prepared in rabbits either stabilized or enhanced the enzyme activity in a dose-response manner. Purified EhCP2 was enclosed within inert resin microspheres (22-44 microm in diameter) and injected into the portal vein of normal hamsters. In the liver, the microspheres caused mild acute inflammation and occasional minimal necrosis of short duration. Sections of the liver were immunohistochemically stained with the anti-EhCP2 antibody and the microspheres were positive for only a very short period (1 h) after injection. Sections of experimental acute (1 day, 5 days) amebic liver abscess produced in hamsters were also stained with the anti-EhCP2 antibody; and amebas were intensely positive but no staining was observed at any time in the surrounding necrotic structures. It is suggested that EhCP2 plays either a minor or no role in the causation of tissue damage in experimental acute liver amebiasis.
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Affiliation(s)
- Alfonso Olivos-García
- Department of Experimental Medicine, National University of México Medical School, Ciudad Universitaria, Apartado Postal 70641, 04510 México, Districto Federal, México
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24
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25
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Pérez-Tamayo R. [Basic science and applied science]. Salud Publica Mex 2001; 43:368-72. [PMID: 11547597] [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: 02/21/2023] Open
Abstract
A lecture was presented by the author at the Democratic Opinion Forum on Health Teaching and Research, organized by Mexico's National Health Institutes Coordinating Office, at National Cardiology Institute "Ignacio Chavez", where he presented a critical review of the conventional classification of basic and applied science, as well as his personal view on health science teaching and research. According to the author, "well-conducted science" is that "generating reality-checked knowledge" and "mis-conducted science" is that "unproductive or producing 'just lies' and 'non-fundable'. To support his views, the author reviews utilitarian and pejorative definitions of science, as well as those of committed and pure science, useful and useless science, and practical and esoterical science, as synonyms of applied and basic science. He also asserts that, in Mexico, "this classification has been used in the past to justify federal funding cutbacks to basic science, allegedly because it is not targeted at solving 'national problems' or because it was not relevant to priorities set in a given six-year political administration period". Regarding health education and research, the author asserts that the current academic programs are inefficient and ineffective; his proposal to tackle these problems is to carry out a solid scientific study, conducted by a multidisciplinary team of experts, "to design the scientific researcher curricula from recruitment of intelligent young people to retirement or death". Performance assessment of researchers would not be restricted to publication of papers, since "the quality of scientific work and contribution to the development of science is not reflected by the number of published papers". The English version of this paper is available at: http://www.insp.mx/salud/index.html
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Affiliation(s)
- R Pérez-Tamayo
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México.
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26
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González-Avila G, Iturria C, Vadillo F, Terán L, Selman M, Pérez-Tamayo R. 72-kD (MMP-2) and 92-kD (MMP-9) type IV collagenase production and activity in different histologic types of lung cancer cells. Pathobiology 2000; 66:5-16. [PMID: 9577961 DOI: 10.1159/000027989] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [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: 12/12/2022] Open
Abstract
In this study we examined the production of gelatinases A and B (MMP-2 and MMP-9), and their natural inhibitors TIMP-1 and TIMP-2 in cell lines derived from different histologic types of lung cancer. Gelatinolytic activity was measured by zymography and radiolabeled gelatin degradation. Immunocytochemistry and Western blot analysis were performed to corroborate the presence of immunoreactive MMP-2, MMP-9, TIMP-1 and TIMP-2 proteins. The highest gelatinolytic activity was identified in the cell extracts from a small-cell carcinoma cell line. MMP-9 was observed in all samples as a proenzyme, while MMP-2 was present as zymogen in the squamous-cell and in the small-cell carcinomas, and in its active form in one squamous-cell carcinoma cell line. TIMPs were also present in the neoplastic lung cell lines. TIMP-1 was observed in the media of all cells as a 21-kD band, and as TIMP-1 polymers with the exception of the small-cell carcinoma samples. TIMP-2 was found as higher-order molecular immunoreactive complexes that may correspond to proMMP-2/TIMP-2 complexes. These results demonstrate that lung neoplastic cells produce both MMP-2 and MMP-9 and their inhibitors, with the small-cell carcinoma cell extracts showing the highest enzymatic activity. This gelatinolytic activity fits well with the clinical metastatic behavior of this type of lung cancer.
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Affiliation(s)
- G González-Avila
- Department of Immunology, Instituto Nacional de Enfermedades Respiratorias, México, DF (México)
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27
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Abstract
We examined the molecular mechanisms of the cytotoxicity of Entamoeba histolytica, using the loss of transepithelial electrical resistance (TER) of monolayers of Madin-Darby canine-kidney (MDCK) cells on their incubation with axenic trophozoites of the HM1-IMSS strain. Such loss of TER occurs very early (in 2-5 min) and is caused by the opening of tight junctions and the detachment of cells. We used specific inhibitors for three of the four molecules currently accepted as being responsible for cytotoxicity: galactose-specific adhesin(s), phospholipase A, and cysteine proteinases. We also used inhibitors of calcium channels. Axenic trophozoites of E. histolytica strain HM1-IMSS were preincubated with the different inhibitors for 1 h prior to their coincubation with MDCK-cell monolayers. The only inhibitor that effectively blocked the loss of TER caused by the parasite was galactose. We suggest that in this experimental model, galactose-specific adhesin(s) are essential for amebic cytotoxicity.
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Affiliation(s)
- R López-Vancell
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México y Hospital General de México, DF
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28
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Ruiz-Argüelles GJ, Velázquez BM, Pérez-Tamayo R, Marín-López A, Salgado-Sánchez J, Porras-Ramírez G, Angel Mercado M, Sánchez-Brito LG. Splenectomy complications in hematological diseases. Rev Invest Clin 1998; 50:347-50. [PMID: 9830325] [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: 02/09/2023]
Abstract
The postoperative complications observed in a group of 27 patients with hematological diseases that underwent splenectomy are reported: 21 patients had a non-malignant hematological condition, whereas the rest had a hematological malignancy. Seven complications presented in 6 patients (two wound infections, two severe post-operative hemorrhages, one incisional hernia, one sepsis by capsulated bacteria and one fatal hemophagocytic syndrome). The overall complication rate was 27%, whereas the fatal complication rate was 3%. The complication rate in patients with malignant diseases was 83%, whereas that in benign conditions was 9%. The size of the spleen was related with the complication rate (median weight of patients with complications was 990 g versus 132 g in those without complications; p < 0.01). The two patients that underwent splenectomy before age six months had complications, in one case related to parental negligence. In splenectomies performed for hematological disease the benefits must be balanced carefully against the risks.
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29
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Becker I, Pérez-Montfort R, Pérez-Torres A, Rondán-Zárate A, Montfort I, Pérez-Tamayo R. Entamoeba histolytica: localization of a 30-kDa cysteine proteinase using a monoclonal antibody. Exp Parasitol 1996; 82:171-81. [PMID: 8617344 DOI: 10.1006/expr.1996.0022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [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
We produced a monoclonal antibody against a major cysteine proteinase of 30kDa from trophozoites of Entamoeba histolytica strain HM1:IMSS. The specificity of the monoclonal antibody was confirmed by specific inhibition of azocasein digestion and by electrophoretic analysis, in the presence of sodium dodecyl sulfate or on a substrate gel, of the antigen precipitated by the antibody. Immunofluorescent staining of trophozoites with the monoclonal antibody revealed heterogeneity in the intensity of whole cell fluorescence and subcellular localization of the stain. The latter was also observed in trophozoites, which were stained by conventional immunohistochemical methods, from experimental liver abscesses in hamsters. Ultrastructural analysis showed antigen distributed mainly in clear amorphous zones in the cytoplasm, which were not limited by a visible membrane. Proteinases are translocated from these compartments to phagocytic vacuoles after trophozoites ingest erythrocytes, suggesting that these regions might be a lysosomal equivalent of this primitive eukaryotic cell.
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Affiliation(s)
- I Becker
- Departamento de Medicina Experimental, Facultad de Medicina U.N.A.M., Mexico City D.F., Mexico
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Montfort I, Pérez-Tamayo R, Pérez-Montfort R, González Canto A, Olivos A. Purification and immunologic characterization of a 30-kDa cysteine proteinase of Entamoeba histolytica. Parasitol Res 1994; 80:607-13. [PMID: 7855127 DOI: 10.1007/bf00933010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [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: 01/27/2023]
Abstract
A 30-kDa cysteine proteinase was purified from extracts of axenically grown trophozoites of Entamoeba histolytica strain HM1:IMSS. The purification procedure involved two consecutive chromatographic steps. Sequence analysis revealed high similarity with histolysin and with other 27-kDa cysteine proteinase. Western-blot analysis using F(ab')2 fragments of a polyclonal antibody raised against the purified enzyme revealed that when the amebic extract was prepared in the absence of proteinase inhibitors there were many positive bands ranging in relative molecular weight from 115 to 12.5 kDa, but when the extract was prepared in the presence of proteinase inhibitors there was only a single 30-kDa positive band. Similar results were obtained with immunoprecipitates. This phenomenon would suggest the formation of multimer aggregates of the 30-kDa cysteine proteinase after partial proteolysis.
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Affiliation(s)
- I Montfort
- Department of Experimental Medicine, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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Abstract
Phagocytosis has been suggested as a marker of pathogenicity and virulence in Entamoeba histolytica. Irmgard Montfort and Ruy Pérez-Tamayo here review the evidence for this suggestion.
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Affiliation(s)
- I Montfort
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad National Autónoma de Mexico, Ciudad Universitaria, México, D.F., 04510, México
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Montfort I, Pérez-Tamayo R, Canto AG, del Carmen García de León M, Olivos A, Tello E, Perez-Tamayo R, Canto AG, del Carmen Garcia de Leon M. Role of Cysteine Proteinases of Entamoeba histolytica on the Cytopathogenicity of Axenic Trophozoites on Rat and Hamster Hepatocytes In vitro. J Parasitol 1993. [DOI: 10.2307/3283284] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Montfort I, Pérez-Tamayo R, González Canto A, García de León MC, Olivos A, Tello E. Role of cysteine proteinases of Entamoeba histolytica on the cytopathogenicity of axenic trophozoites on rat and hamster hepatocytes in vitro. J Parasitol 1993; 79:98-105. [PMID: 8437063] [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: 01/30/2023] Open
Abstract
The role of amebic cysteine proteinase(s) on the in vitro cytotoxic and cytolytic effects of axenic trophozoites of a virulent strain (HM-1) of Entamoeba histolytica has been studied using freshly isolated rat and hamster hepatocytes as target cells. The cytotoxic effect was defined as cell killing without loss of cell structure and the cytolytic effect as cell disintegration. Incubation experiments of axenic trophozoites with rat or hamster liver cells in the presence and absence of bovine serum, of several proteinase inhibitors, and of galactose, galactosamine, and cysteine, at various ameba:liver cell ratios, different temperatures, and for several time periods, suggest that amebic cysteine proteinase is not involved in the cytotoxic effect but is essential for the cytolytic effect. This suggestion is supported by additional observations made with Transwell chambers, which effectively prevent contact between amebas and target cells, and by experiments with a fraction of an extract of lysed amebas that contained most of their cysteine proteinase activity.
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Affiliation(s)
- I Montfort
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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Abstract
To examine the relationship between phagocytosis, proteinase activity and pathogenicity of axenically grown trophozoites of E. histolytica strain HM-1:IMSS four different cultures were used: (1) a culture preserved in our laboratory for over 4 years, which lost its pathogenicity 3 years ago; (2) a culture passaged several times through hamster liver, which lost its pathogenicity recently; (3) a highly virulent culture supplied by another laboratory; and (4) amebas recovered from hamster liver abscesses caused by culture 3. Phagocytosis was measured as erythrophagocytosis. Proteinase activity was determined on azocasein. Pathogenicity was defined as the capacity to cause liver abscesses in hamsters. A negative correlation was found between phagocytic activity and pathogenicity, since amebas unable to cause liver abscesses had the highest phagocytic activity, whereas those recovered from liver abscesses had the lowest phagocytic activity. The percent of phagocytic amebas showed wide variations through a 2-month observation period, with no change in amebic pathogenicity. No correlation was found between the level of proteinase activity and pathogenicity. It is concluded that neither phagocytosis nor proteinase activity is an adequate marker of amebic pathogenicity.
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Affiliation(s)
- I Montfort
- Department of Experimental Medicine, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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Abstract
In experimental acute amebic liver abscess, produced in hamsters by the intraportal inoculation of 1 x 10(6) axenic trophozoites of Entamoeba histolytica strain HM-1, we examined the blood perfusion of the lesions 5, 10, 24 and 72 h after injection of the parasites. India ink introduced into the portal circulation filled all liver vessels but was systematically excluded from even the earlier amebic lesions. The absence of serum proteinase inhibitors from the lesions may allow the participation of amebic proteinases in the causation of tissue necrosis.
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Affiliation(s)
- R Pérez-Tamayo
- Department of Experimental Medicine, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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Pérez-Tamayo R, Martínez RD, Montfort I, Becker I, Tello E, Pérez-Montfort R. Pathogenesis of acute experimental amebic liver abscess in hamsters. J Parasitol 1991; 77:982-8. [PMID: 1779303] [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: 12/28/2022] Open
Abstract
The hypothesis was tested that tissue necrosis in acute experimental amebic liver abscess in hamsters is not caused directly by the parasite but rather, indirectly, by the destruction of closely surrounding leukocytes that release their lysosomal enzymes and damage neighboring liver cells. Axenically grown trophozoites of Entamoeba histolytica strain HM-1 were injected intraportally into normal, hypocomplementemic, and leukopenic hamsters, and the lesions were studied histologically 2, 5, 10, and 24 hr after injection. Hypocomplementemia (less than 5% of normal CH50) and leukopenia (less than 1,000 leukocytes/ml) were achieved and sustained for up to 72 hr with repeated intraperitoneal injections of goat anti-hamster C3 and anti-hamster leukocyte antibodies, respectively. Decrease or absence of polymorphonuclear leukocytes in the vicinity of intrahepatic amebas effectively blocked deleterious effects of the parasites on surrounding hepatocytes. We conclude that in acute experimental amebic liver abscess the direct effect of the parasites on hepatocytes and their stroma is not responsible for tissue necrosis, but rather it is due to their indirect action through the destruction of inflammatory cells.
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Affiliation(s)
- R Pérez-Tamayo
- Sub-División de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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Pérez-Tamayo R, Becker I, Montfort I, Ostoa-Saloma P, Pérez-Montfort R. Role of leukocytes and amebic proteinases in experimental rat testicular necrosis produced by Entamoeba histolytica. Parasitol Res 1991; 77:192-6. [PMID: 2047366 DOI: 10.1007/bf00930857] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [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: 12/30/2022]
Abstract
To investigate the role of amebic proteinases and host leukocytes, we studied amebiasis experimentally in the rat testis. The degree of inflammation and necrosis produced by different strains was correlated with proteinase activity and with zymograms. Intratesticular injection of axenically grown trophozoites of a pathogenic strain (HM-1 of Entamoeba histolytica) produced indistinguishable lesions in normal animals and leukopenic rats (less than 1000 leukocytes/mm3), suggesting that granulocytes do not contribute to the formation of lesions in this model. Testicular lesions produced by five different strains of E. histolytica ranging from highly virulent to almost nonpathogenic were proportional to the proteinase activity of each amebic strain. Inhibition of amebic proteinases in vitro and subsequent injection into the rat testis markedly reduced the inflammatory lesions resulting from highly virulent E. histolytica. The pathogenicity of three other amebae (E. laredo, E. moshkovskii, and E. invadens) was generally proportional to their proteinase activity; however, E. laredo showed high proteinase activity and caused minimal tissue damage. These results suggest that the pathogenic potential of Entamoeba spp. in the rat testis may be related to the type as well as the level of their proteinase activity.
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Affiliation(s)
- R Pérez-Tamayo
- Sub-División de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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Abstract
T-cell suppression induced by concanavalin-A (Con-A) and the prostaglandin suppressor system (PSS) were studied in 14 patients with pigeon breeder's disease (PBD), 12 and 10 asymptomatic breeders, and 8 controls. Our results showed that PBD patients display a significant decrease in T-cell-induced suppression (29.6 +/- 15.3% vs. 61.2 +/- 9.3% in controls p less than 0.05); whereas asymptomatic breeders respond heterogeneously: 5 showed decreased suppression and 7 were within the normal range obtained in controls. In contrast, the patients presented a higher PSS index compared with the other 2 groups, suggesting an inverse relationship between the 2 systems. These findings indicate that there are relevant differences between PBD patients, asymptomatic breeders, and normal subjects in some immune interactions, which may at least partially explain the characteristic cellular and humoral hyperreactivity observed in patients with this disease.
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Affiliation(s)
- N Barquín
- Instituto Nacional de Enfermedades Respiratorias, Facultad de Medicina, UNAM, Mexico City
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Montfort I, Pérez-Tamayo R, Alvizouri AM, Tello E. Collagenase of hepatocytes and sinusoidal liver cells in the reversibility of experimental cirrhosis of the liver. Virchows Arch B Cell Pathol Incl Mol Pathol 1990; 59:281-9. [PMID: 1980558 DOI: 10.1007/bf02899415] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In order to explore the cellular source(s) and the behaviour of the collagenolytic activity previously described in rat liver homogenates, in the reversibility of experimental cirrhosis of the liver, enriched suspensions of hepatocytes and of sinusoidal liver cells were obtained by a procedure which employs low EDTA concentrations and no bacterial collagenase. Cell suspensions were prepared from three different groups of animals: 1) normal controls, 2) rats with CCl4-induced cirrhosis of the liver, and 3) rats with swine serum-induced cirrhosis of the liver. Animals were sacrificed in each group upon completion of treatment and also after 3, 6 and 12 months. In each liver wet weight and collagen concentration were determined, and collagenolytic activity of both enriched cell suspensions was measured separately. In addition, histological studies of liver tissue and ultrastructural examination of cell suspensions were performed by standard procedures. Enriched suspensions of both normal hepatocytes and sinusoidal liver cells display Ca2(+)-dependent collagenolytic activities. Both cell suspensions obtained from each of the two types of cirrhotic livers show normal or slightly increased average levels of collagenase activity at the time of treatment discontinuation, when average liver collagen content ranges from 6 to 10-fold over normal, suggesting that the normal collagenase/collagen ratio is disturbed and that collagenolytic activity is deeply decreased in relation to the actual liver collagen load.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- I Montfort
- Sub-Division de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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Selman M, Montaño M, Ramos C, Barrios R, Pérez-Tamayo R. Experimental pulmonary fibrosis induced by paraquat plus oxygen in rats: a morphologic and biochemical sequential study. Exp Mol Pathol 1989; 50:147-66. [PMID: 2707380 DOI: 10.1016/0014-4800(89)90027-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [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: 01/02/2023]
Abstract
Changes in lung structure and collagen metabolism were studied at 1, 2, 3, 4, 6, and 8 weeks in a model of pulmonary fibrosis induced in rats with paraquat plus hyperoxia. Morphologic examination of the lungs revealed that the earliest lesions consisted of severe and irreversible endothelial and alveolar epithelial cell damage. Afterward, an inflammatory process took place, initially dominated by polymorphonuclear leukocytes and then by mononuclear cells, but with the constant presence of granulocytes. From the fourth week on there were fibroblast proliferation and a moderate increase of mast cells. In the early stages alveolitis was focal, but from the second week the lungs were diffusely affected with severe distortion of the architecture. Collagen content was moderately increased in the first 2 weeks and then showed a progressive increment until the end of the experiment. Collagen synthesis was significantly elevated from the fourth week, coinciding with interstitial fibroblast proliferation, although there were some animals that showed increased collagen production from the first week. Collagenolytic activity occurred in 3 stages: at 2 weeks there was increased collagen degradation, at 3, 4, and 6 weeks the values showed a trimodal behavior, and at 8 weeks almost all experimental rats presented an important decrease of collagenolysis. Thus, the development of lung fibrosis was associated first with increased rates of collagen synthesis and later with a decrease of collagen degradation.
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Affiliation(s)
- M Selman
- Departamento de Enfermedades Crónico-Degenerativas, Instituto Nacional de Enfermedades Respiratorias SSA, Mexico DF, Mexico
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Becker I, Pérez-Tamayo R, Montfort I, Alvizouri AM, Pérez-Montfort R. Entamoeba histolytica: role of amebic proteinases and polymorphonuclear leukocytes in acute experimental amebiasis in the rat. Exp Parasitol 1988; 67:268-80. [PMID: 2903831 DOI: 10.1016/0014-4894(88)90074-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [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: 01/03/2023]
Abstract
The injection of 1 x 10(6) trophozoites of axenically grown Entamoeba histolytica strain HM-1 in the subcutaneous tissue of the rat results in an acute and self-limited inflammatory process, characterized by the early onset of conspicuous tissue necrosis and focal hemorrhage in the vicinity of the parasites, followed by infiltration with polymorphonuclear leukocytes. The process develops for 5-10 hr but during that period amebic trophozoites progressively disappear, leukocytes undergo degenerative changes, and the lesion tends to heal in 72-96 hr. In leukopenic animals (less than 1000 white blood cells/ml) tissue necrosis and hemorrhage are equally conspicuous in the neighborhood of amebas. Inhibition of amebic proteinase activity prior to injection by heat denaturation, p-hydroxy-mercuri-benzoate (PHMB), soybean trypsin inhibitor (STI), and human alpha-2-macroglobulin (alpha 2M), alone or in various combinations, results in absence or notorious decrease in tissue necrosis as well as in clearly diminished inflammatory reaction. This effect is particularly evident when cysteine proteinases are either specifically or generally inhibited. On the other hand, amebic proteinase inhibition with alpha 2M and STI does not interfere with the cell-killing capacity of trophozoites co-incubated in vitro for 2 hr with rat peritoneal cells enriched for macrophages. We conclude that in acute experimental amebiasis produced in the subcutaneous tissue of the rat, amebic cysteine (and perhaps other) proteinases are primarily responsible for necrosis and are also important, but not essential, for inflammation. We also suggest that in this model polymorphonuclear leukocytes are not required for tissue necrosis. Finally, in an in vitro model, the cell-killing capacity of amebas is not influenced by the proteinase activity of the parasite.
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Affiliation(s)
- I Becker
- Sub-División de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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González-Avila G, Vadillo-Ortega F, Pérez-Tamayo R. Experimental diffuse interstitial renal fibrosis. A biochemical approach. J Transl Med 1988; 59:245-52. [PMID: 3404976] [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: 01/05/2023] Open
Abstract
In this paper we describe two simple experimental models of diffuse interstitial renal fibrosis in the rat. One develops 25 days after unilateral renal vein ligation, and the other 15 days after unilateral ureteral double ligation and section. In both models fibrosis is examined morphologically and biochemically, the latter with emphasis on collagen turnover. In addition to a description of the histology, also presented are quantitative biochemical data on four features of tissue collagen turnover, namely total content, concentration, biosynthesis, and degradation. Although the microscopic picture of both models can be adequately described as interstitial diffuse renal fibrosis, their mechanisms are different: unilateral renal vein ligation is an example of collapse fibrosis, whereas unilateral ureteral double ligation and section is a model of absolute fibrosis. In both models however, decreased collagen degradation is the significant metabolic abnormality.
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Affiliation(s)
- G González-Avila
- Subdivision de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, México City
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Abstract
The duration of the pulmonary paraquat toxicity-enhancement effect of O2 has been examined in Wistar rats. In one experiment, various groups of normal animals were given a single dose (5 mg/kg body wt) of paraquat and after different periods were exposed to continuous breathing of normobaric 74% O2 in airtight chambers until dead or up to 10 days. In a reverse experiment, a large number of rats were first exposed for 6 days to continuous breathing of normobaric 74% O2 and were then separated into various groups which received a single dose of paraquat (5 mg/kg body wt) after various periods of breathing normal air, ranging from 0 to 96 hr. The extent of pulmonary damage in both experiments was evaluated by histologic examination and by biochemical determination of total collagen content of the lungs. It was found that the duration of the pulmonary damage induced by paraquat that is enhanced by continuous breathing of high O2 concentration lasts 24 to 48 hr. It was also observed that 12 to 24 hr after paraquat administration and continuous breathing of high O2 concentration pulmonary lesions are severe and extensive, and in animals surviving 6 or more days there was also incipient interstitial fibrosis. The reverse sequence of treatment (O2 + paraquat) resulted in no mortality and no pulmonary lesions. Additional controls treated with each of the pulmonary toxins alone also revealed no lung changes.
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Abstract
We have produced experimental diffuse interstitial pulmonary fibrosis in rats with a combination of low and repeated doses of paraquat plus continuous exposure to normobaric 74% O2 in the breathing air for several weeks. Pulmonary fibrosis was evaluated histologically and biochemically, through the determination of total collagen content in the lung. Our procedure is characterized by low initial mortality, the development of extensive distortion of the pulmonary architecture, and the presence of severe and diffuse interstitial fibrosis. The model was compared with bleomycin-induced pulmonary fibrosis in the same rat strain, in which the process is focal and leaves most of the lung unaffected. We conclude that lung damage produced by the combination of low doses of paraquat plus normobaric 74% O2 concentration in the breathing air is an adequate experimental model of diffuse interstitial pulmonary fibrosis as it occurs in many of the human cases of this condition.
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Jinich H, Pérez-Tamayo R, Sepúlveda B, Guarner V. [Truth and error in medicine]. GAC MED MEX 1984; 120:133-44. [PMID: 6386587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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Abstract
The presence of isolated epithelioid granulomata (EG) in the tissue samples of patients with malignant lymphomata (MT) has been related to a better prognosis. Miliary tuberculosis (MT) is frequent in Mexico (2.1 per 1000 patients at the Instituto Nacional de la Nutrición), where physicians dealing with the diagnostic and therapeutic approach of patients with ML and EG face the problem of differentiating the latter due to concurrent MT or to the neoplasm. Twenty-five patients with ML + MT and seven with ML + EG without MT were identified along 12 years; 32 ML patients matched according to age, sex, stage, type of ML and treatment were selected and their survival compared with that of the former groups. The prevalence of MT in ML patients was 35 times higher than that of the general population (P less than 0.001). Even though 6 and 18 month survival in patients with ML and MT or EG was higher than that of ML alone, differences are insignificant. It is concluded that the coexistence of MT and ML does not worsen the prognosis of ML; the high prevalence of MT in ML patients in selected countries could lead to the routinary administration of prophilactic antituberculous treatment.
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Pardo A, Rosenstein I, Montfort I, Pérez-Tamayo R. Immunohistochemical identification of collagenase in carrageenin granuloma. J Histochem Cytochem 1983; 31:641-6. [PMID: 6302163 DOI: 10.1177/31.5.6302163] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [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] Open
Abstract
The collagenase present in experimental carrageenin granuloma in the guinea pig has been purified to homogeneity in acrylamide gel electrophoresis by a combination of ammonium sulfate salting out and affinity chromatography on Sepharose 4B--collagen-packed columns. The single protein band thus obtained was used as an antigen to obtain a monospecific antibody in heterologous conditions. Several immunodiffusion, immunoaffinity chromatography, and immunoinhibition tests of the antibody against the specific antigen and various possible serum and tissue contaminants suggested that the antibody was specifically directed against the enzyme protein collagenase. Indirect immunohistochemical staining of carrageenin granulomas, samples at different developmental phases with this specific anti-collagenase antibody, revealed that the specific antigenic protein (the enzyme collagenase) is universally present on the extracellular structures at both the collagen-deposition and the collagen-resorption stages. A hypothesis is proposed to account for these findings, namely, that the enzyme collagenase is bound to its substrate (collagen) under both normal and pathological conditions, and that the critical point of control of collagen degradation must be the activation of the collagen-bound enzyme.
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García Tsao G, Frenk A, Maisterrena J, Foucell S, DeGaiter M, Pérez-Tamayo R, Adame MA, Estrella H, Flores-Lozano F, Gómez Vargas E, Laviada E, Macías TV, Ovalle F, Quibrera R, Rivera-Damm R, Vargas L, Valverde C. [Study Group for Thyroid Cancer in Mexico (CATIMEX). Collaborative study of 194 cases]. Rev Invest Clin 1983; 35:3-14. [PMID: 6867510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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50
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Pérez-Tamayo R, Montfort I. The susceptibility of hepatic collagen to homologous collagenase in human and experimental cirrhosis of the liver. Am J Pathol 1980; 100:427-42. [PMID: 6157326 PMCID: PMC1903529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The susceptibility of hepatic collagen to homologous collagenase in human and experimental CCl4 cirrhosis of the liver has been explored in vitro by exposure of cryostat liver sections to the corresponding enzymes for different time periods. The morphology and extent of collagen degradation was studied by the Picrosirius red/polarizing microscopy technique. The results of various experiments indicate that collagen present in cryostat sections of both human and rat normal and cirrhotic livers is resistant to trypsin digestion for periods of exposure of up to 48 hours but that heating the sections to 60 C for 1 hour renders the collagen susceptible to degradation by trypsin. Incubation of cryostat liver sections with bacterial collagenase revealed progressive degradation of collagen with a uniform pattern of changes in the original color and diameter of the fibers. Exposure of liver sections to homologous collagenases gave rise to the same pattern of changes observed with bacterial collagenase, although less extensive when equal incubation periods were compared. Nevertheless, sufficiently prolonged incubation of liver sections with their homologous collagenases eventually showed degradation of all collagen present in all normal and cirrhotic liver sections. These observations suggest that in the presence of non rate-limiting concentrations of homologous collagenase, the susceptibility of hepatic collagen to the corresponding degrading enzyme is probably not responsible for the irreversibility of the disease.
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