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Jara C, Gaete H, Lobos G, Hidalgo ME. Oxidative stress in the mollusk Echinolittorina peruviana (Gasteropoda: Littorinidae, Lamarck, 1822) and trace metals in coastal sectors with mining activity. Ecotoxicology 2014; 23:1099-1108. [PMID: 24829115 DOI: 10.1007/s10646-014-1253-3] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/27/2014] [Indexed: 06/03/2023]
Abstract
The aim of the study was to evaluate the effect of coastal waters of sites with mining activity in Echinolittorina peruviana, through oxidative stress biomarkers and heavy metals determination both in water and in tissue. Organisms were collected in the intertidal zone in areas with and without mining activity. Metal concentrations in the water and tissues, and also, the following biomarkers of oxidative stress: antioxidant enzyme activity, superoxide dismutase and catalase, non-enzymatic oxidative capacity (TRAP), oxidative damage to proteins (carbonyls) and TBARS, were measured The concentrations of accumulated metals had the following order Fe > Cu > Cd > Zn > Cr > Mo > As; the highest concentrations of metals in water and tissues were found in Caleta Palito and Chañaral. Results suggest that the coastal waters with mining activity and greatest concentrations of copper and iron induced the greater antioxidant response and oxidative damage to lipids in E. peruviana.
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Affiliation(s)
- C Jara
- Laboratorio de Investigación-Estrés Oxidativo, Facultad de Medicina, Universidad de Valparaíso, Av. Brasil, 1560, Valparaíso, Chile
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Carrasco-Malio A, Díaz M, Mella M, Montoya MJ, Miranda A, Landaeta MF, Sánchez G, Hidalgo ME. Are the intertidal fish highly resistant to UV-B radiation? A study based on oxidative stress in Girella laevifrons (Kyphosidae). Ecotoxicol Environ Saf 2014; 100:93-98. [PMID: 24238740 DOI: 10.1016/j.ecoenv.2013.07.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 07/24/2013] [Accepted: 07/29/2013] [Indexed: 06/02/2023]
Abstract
Sea chub, Girella laevifrons, is a coastal fish that inhabits high intertidal rockpools along the coast of Chile. The intertidal pools where the juveniles live, are an extreme environment with high levels of ultraviolet (UV) radiation, becoming harmful to the organisms, due to oxidative stress generated by reactive oxygen species. For this reason organisms develop adaptations that allow them to survive in this complex environment. The search of biomonitor species, sensitive to UV radiation is very important in aquatic ecosystems, mainly in the southern hemisphere where depletion of the ozone layer and the consequent increase of UV radiation, have become an environmental problem. The aim of this study was to evaluate the effect of ultraviolet radiation in G. laevifrons and its possible use as UV-B radiation biomonitor specie in intertidal systems, which are very important for the Chilean fisheries. The effect of UV radiation exposure on juvenile G. laevifrons was measured through oxidative stress parameters. Catalase's activity increased with the time of exposure, unlike superoxide dismutase's activity which peaked at 2h, decreasing towards the 5th hour of irradiation. The superoxide dismutase activity in muscle tissue did not show significant differences. The lipid peroxidation and DNA damage increased in relation to exposition times. Tissue muscle's DNA damage was shown only at 5h of exposure. Significant differences between the two organs in the antioxidant capacity were observed, the liver of G. laevifrons exhibited the higher antioxidant capacity. It can be concluded that this specie exhibits effective protection mechanisms against UV radiation exposure and it is not appropriate specie as a biomonitor in intertidal systems.
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Affiliation(s)
- A Carrasco-Malio
- Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Avenida Borgoño 16344, Reñaca, Viña del Mar, Chile
| | - M Díaz
- Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Avenida Borgoño 16344, Reñaca, Viña del Mar, Chile
| | - M Mella
- Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Avenida Borgoño 16344, Reñaca, Viña del Mar, Chile
| | - M J Montoya
- Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Avenida Borgoño 16344, Reñaca, Viña del Mar, Chile
| | - A Miranda
- Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Avenida Borgoño 16344, Reñaca, Viña del Mar, Chile
| | - M F Landaeta
- Laboratorio de Ictioplancton (LABITI), Facultad de Ciencias del Mar y de Recursos Naturales, Universidad de Valparaíso, Avenida Borgoño 16344, Reñaca, Viña del Mar, Chile
| | - G Sánchez
- Facultad de Farmacia, Universidad de Valparaíso, Avda. Gran Bretaña 1093, Playa Ancha, Valparaíso, Chile.
| | - M E Hidalgo
- Facultad de Ciencias, Universidad de Valparaíso, Avda. Gran Bretaña 1111, Playa Ancha, Valparaíso, Chile
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Gaete H, Hidalgo ME, Neaman A, Ávila G. Evaluación de la toxicidad de cobre en suelos a través de biomarcadores de estrés oxidativo en eisenia foetida. QUIM NOVA 2010. [DOI: 10.1590/s0100-40422010000300014] [Citation(s) in RCA: 14] [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: 11/22/2022] Open
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Aránguiz F, Gaete H, Hidalgo ME, Lobos G. Daño oxidativo en la microalga Pseudokirchneriella subcapitata expuesta a aguas receptoras de un efluente minero en del Río Blanco (V Región, Chile). QUIM NOVA 2009. [DOI: 10.1590/s0100-40422009000900034] [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: 11/21/2022] Open
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Dinamarca VM, Hidalgo ME, Cavieres MF. Lack of effects of 2,4-dichlorophenoxyacetic acid administration on markers of oxidative stress during early pregnancy in mice. Toxicology 2007; 237:104-110. [PMID: 17582670 DOI: 10.1016/j.tox.2007.05.002] [Citation(s) in RCA: 10] [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: 03/02/2007] [Revised: 04/27/2007] [Accepted: 05/01/2007] [Indexed: 10/23/2022]
Abstract
Induction of oxidative stress by 2,4-dichlorophenoxyacetic acid (2,4-D) both as a pure compound and in commercial formulation was investigated during early pregnancy in mice. Pregnant animals were exposed to increasing doses of the herbicide (0.01, 0.1 and 100mg/kg/d) during gestation days 0-9, after which animals were euthanized and their blood analyzed for catalase activity, thiobarbituric acid reactive substances (TBARs) and total antioxidant capacity (TAC). Number of corpora lutea and uterine implantations and resorptions were also determined. Herbicide exposure did not cause any overt signs of maternal toxicity at any of the doses administered; neither did it cause an effect on developmental parameters. Catalase activity and TBARs were not modified by herbicide exposure although TAC was significantly decreased at 100mg/kg/d of both pure and formulated compound. Thus, 2,4-D does not seem to induce oxidative stress during early pregnancy in mice at the doses administered, indicating that this mechanism is probably not involved in mediating herbicide toxicity at these dose levels. Furthermore, since no manifestations of developmental toxicity were observed after administration of the herbicide, it is also possible that 2,4-D may not produce any early developmental toxicity at the low environmentally relevant doses tested in this animal model.
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Sánchez G, Hidalgo ME, Vivanco JM, Escobar J. Induced and Photoinduced DNA Damage by Quinolones: Ciprofloxacin, Ofloxacin and Nalidixic Acid Determined by Comet Assay¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2005.tb01448.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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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Abstract
Lichens synthesize and accumulate photoprotective compounds against possible damage induced by UV radiation in the photobiont. A biological model has been recently formulated that allows the use of lichens to evaluate changes at different UV radiation levels. The thermodynamics, photophysical and photochemical properties of lobaric acid were studied in acetonitrile, ethanol and Brij 35(3%) micelles at different pH values. Also the sun protector factor (SPF) was determined by in vitro methods. Lobaric acid was extracted from Stereoculon alpinum Laur. and characterized by means of standard procedures. Solutions were irradiated in oxygen and under nitrogen conditions with a UV medium pressure lamp. Lobaric acid absorbs at 287, 303 nm, and no fluorescence emission was observed. The maximum value of the molar extinction coefficient (5479.6 M(-1) cm(-1)) was obtained in Brij 35 at pH 12. Solubility is pH dependant and is highest in Brij 35 at pH 12 (4.45 x 10(-4) M). Photoconsumption quantum yields ranged between 10(-4) and 10(-5) in aerobic and anaerobic experimental conditions. Lobaric acid SPF was very low (0.5) compared with homosalate (4.0), (reference solar filter). Two pKa values, 5.05 (carboxylic acid group deprotonation) and 9.75 (phenolic OH deprotonation), were determined.
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Affiliation(s)
- María Eliana Hidalgo
- Chemistry and Biology Institute, Faculty of Science, University of Valparaíso, Valparaíso, Chile.
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Fernández E, Quilhot W, Rubio C, Hidalgo ME, Diaz R, Ojeda J. Effects of UV Radiation on Usnic Acid in Xanthoparmelia microspora (Müll. Arg. Hale). Photochem Photobiol 2006; 82:1065-8. [PMID: 16620157 DOI: 10.1562/2006-01-19-ra-782] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Hidalgo ME, Farah M, Carrasco L, Fernández E. Photostability and photoprotection factor of boldine and glaucine. Journal of Photochemistry and Photobiology B: Biology 2005; 80:65-9. [PMID: 15963438 DOI: 10.1016/j.jphotobiol.2005.01.005] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Received: 08/29/2004] [Revised: 01/12/2005] [Accepted: 01/12/2005] [Indexed: 11/17/2022]
Abstract
Boldine hydrochloride was more photounstable than boldine after irradiation with UVB (lambda = 300 nm). However, photoconsumption quantum yields, for glaucine hydrochloride (6.5 x 10(-2)) and boldine hydrochloride (6.7 x 10(-2)) in air, were quite similar. The photolysis was oxygen dependent in both cases, and the effect over the kinetics after the addition of 2,2,6,6-tetramethyl-1-piperidinyloxy suggested free radicals participation. The fact that the antioxidative capacity of boldine and boldine hydrochloride did not change during the photolysis, suggests that the phenolic structure remains unchanged in the photoproducts, corroborated with the photoproducts analysis. The photoprotection capacity was evaluated before and after irradiation. Results indicate that the values before irradiation are similar for all three compounds, only glaucine increasing its capacity with length of irradiation time.
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Affiliation(s)
- María Eliana Hidalgo
- Chemistry and Biology Institute, Faculty of Sciences, University of Valparaíso, Chile.
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Sánchez G, Hidalgo ME, Vivanco JM, Escobar J. Induced and photoinduced DNA damage by quinolones: ciprofloxacin, ofloxacin and nalidixic acid determined by comet assay. Photochem Photobiol 2005; 81:819-22. [PMID: 15691228 DOI: 10.1562/2004-11-30-ra-386] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Quinolones are degraded by light with loss of their antimicrobial activity, generating active species or radicals. Evidence exists that some fluoroquinolones (lomefloxacin, fleroxacin and enoxacin) induce damage to the cellular membrane and DNA cleavage by photosensitization. In this study, the genotoxic potential of the quinolones ofloxacin, nalidixic acid and ciprofloxacin (three antimicrobials frequently used in therapy) was evaluated upon irradiation with UV light by using the comet assay on cells of the Jurkat line. The results demonstrate that there are significant differences between the control groups (positive control with 50 microM H2O2, negative controls without drug and with and without irradiation) and the groups of irradiated quinolones (ofloxacin 2.76 x 10(-5) M, nalidixic acid 2.15 x 10(-4) M and ciprofloxacin 2.01 x 10(-5) M), indicating that, at the dose of irradiation employed (necessary to produce 50% photodegradation), the photodecomposition of the quinolones enhanced DNA damage. The unirradiated drugs also exhibited genotoxicity significantly different from that of the negative control.
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Affiliation(s)
- Georgina Sánchez
- Facultad de Farmacia, Universidad de Valparaíso, Valparaíso, Chile.
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Sánchez G, Hidalgo ME, Vivanco JM, Escobar J. Induced and Photoinduced DNA Damage by Quinolones: Ciprofloxacin, Ofloxacin and Nalidixic Acid Determined by Comet Assay¶. Photochem Photobiol 2005. [DOI: 10.1562/2004-11-30-ra-386r.1] [Citation(s) in RCA: 19] [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: 11/19/2022]
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Hidalgo ME, Fernández E, Ponce M, Rubio C, Quilhot W. Photophysical, photochemical, and thermodynamic properties of shikimic acid derivatives: calycin and rhizocarpic acid (lichens). J Photochem Photobiol B 2002; 66:213-7. [PMID: 11960732 DOI: 10.1016/s1011-1344(02)00264-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Photophysical and photochemical parameters of the lichen metabolites calycin and rhizocarpic acid were determined. Experiments were carried out in micellar solutions of 3% Brij 35, at pH 2 and 12, and in acetonitrile. Both metabolites absorb in the UV-A and UV-B regions, and emit fluorescence in the visible region of the solar spectrum. Shifts were not observed in the absorption spectra, at pH 2 and 12. The low phi(c), between 10(-5) and 10(-2), shows that both compounds are photostable in the experimental conditions. For rhizocarpic acid, two values of pK(a) were obtained: 5.1 corresponding to the hydroxyl group, and 9.0 corresponding to the protonated nitrogen. Calycin presents only one value of pK(a): 4.9, that is attributed to the hydroxyl group. L-(+)-Gluconic-gamma-lactonic acid was used as a reference model; the compound showed greater photoinstability, demonstrating that the photodegradation observed occurs mainly in the oxolane carbonylic ring.
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Affiliation(s)
- M E Hidalgo
- Chemistry and Biology Institute, Faculty of Sciences, University of Valparaiso, Chile.
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Rubio C, Fernández E, Hidalgo ME, Quilhot W. EFFECTS OF SOLAR UV-B RADIATION IN THE ACCUMULATION OF RHIZOCARPIC ACID IN A LICHEN SPECIES FROM ALPINE ZONES OF CHILE. ACTA ACUST UNITED AC 2002. [DOI: 10.4067/s0366-16442002000100012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Larrea L, Irizar I, Hidalgo ME. Improving the predictions of ASM2d through modelling in practice. Water Sci Technol 2002; 45:199-208. [PMID: 11989872] [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: 05/23/2023]
Abstract
The paper presents the adjustments carried out on the structure and in some default values of the kinetic coefficients of the ASM2d model in order to get an improved prediction for the experimental results obtained in pilot scale plants studies with different activated sludge treatment processes for carbon, nitrogen and phosphorous removal. In order to predict the high effluent filtered COD experimentally observed in high rate processes for carbon removal, a new model structure has been proposed, incorporating into the carbon model a soluble fraction of the slowly biodegradable substrate. Studies with the step feed and the alternating processes showed simultaneous nitrification-denitrification in aerated reactors which was predicted with increased values in the oxygen saturation coefficients for heterotrophic and autotrophic biomass. Both processes also showed loss of the denitrification capacity under unfavourable conditions, such us rains and low anoxic fraction, which required a very large decrease in the value of the reduction factor for denitrification so as to improve the predictions for effluent nitrate experimental results. Regarding phosphorus removal, the ASM2d model showed a satisfactory predictive capacity. For improved predictions of phosphorus release in anaerobic conditions, high values of the rate constant for storage of X(PHA) and low values of the anaerobic hydrolysis reduction factor were used. For phosphorus uptake in aerobic and anoxic conditions satisfactory predictions were obtained using the default values.
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Affiliation(s)
- L Larrea
- Section of Environmental Engineering, CEIT, San Sebastián, Spain
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Abstract
This paper describes a mathematical tool for local identifiability analysis that can easily be applied to high-order state-space nonlinear systems and implemented in simulators with a discrete-time approach. The methodology is based on the recursive numerical evaluation of a reduced information matrix during the simulation of a calibration experiment and in the setting-up of a group of information parameters based on geometric interpretations of this matrix. As an example of application, the proposed methodology has been used in the study of an OUR batch test from the point of view of ASM No. 1 calibration.
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Affiliation(s)
- M E Hidalgo
- Section of Environmental Engineering, CEIT, San Sebastian, Spain.
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Hidalgo ME, Ayesa E. A numerical identifiability test for state-space models--application to optimal experimental design. Water Sci Technol 2001; 43:339-346. [PMID: 11385866] [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: 05/23/2023]
Abstract
This paper describes a mathematical tool for identifiability analysis, easily applicable to high order non-linear systems modelled in state-space and implementable in simulators with a time-discrete approach. This procedure also permits a rigorous analysis of the expected estimation errors (average and maximum) in calibration experiments. The methodology is based on the recursive numerical evaluation of the information matrix during the simulation of a calibration experiment and in the setting-up of a group of information parameters based on geometric interpretations of this matrix. As an example of the utility of the proposed test, the paper presents its application to an optimal experimental design of ASM Model No. 1 calibration, in order to estimate the maximum specific growth rate microH and the concentration of heterotrophic biomass XBH.
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Affiliation(s)
- M E Hidalgo
- Section of Environmental Engineering, CEIT, Po. Manuel Lardizabal, 15, 20018, San Sebastián, Spain
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Hidalgo ME, Rodríguez JC, Vizoso F, Díez MC. [Amebic liver abscess of autochthonous origin: case report]. Enferm Infecc Microbiol Clin 2000; 18:145-6. [PMID: 10905021] [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: 02/17/2023]
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Barbieri ER, Hidalgo ME, Venegas A, Smith R, Lissi EA. Varicocele-associated decrease in antioxidant defenses. J Androl 1999; 20:713-7. [PMID: 10591609] [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: 02/14/2023]
Abstract
Varicocele is associated with an oxidative stress condition. We have measured the antioxidant defenses of varicocele patients both at the local (seminal plasma) and systemic (blood plasma) levels. The antioxidant defenses, as evaluated by the total reactive antioxidant potential parameter, decrease both in the seminal (controls 676+/-128; patients = 386+/-186) and blood (controls = 519+/-63; patients = 268+/-110) plasma of varicocele patients. Compared with controls, patients with both normal spermiograms and spermiograms altered in motility or morphology demonstrated lower values. The results obtained suggest that varicocele-associated oxidative stress is evidenced both at the local and systemic levels. This conclusion is supported by results showing that urinary spontaneous chemiluminescence is also significantly increased in the patients.
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Affiliation(s)
- E R Barbieri
- Faculty of Science, University of Valparaíso, Chile
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Fernández E, Reyes A, Hidalgo ME, Quilhot W. Photoprotector capacity of lichen metabolites assessed through the inhibition of the 8-methoxypsoralen photobinding to protein. J Photochem Photobiol B 1998; 42:195-201. [PMID: 9595708 DOI: 10.1016/s1011-1344(98)00070-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Lichens produce a diversity of phenolic compounds, some of which efficiently absorb ultraviolet radiation, 8-Methoxypsoralen (8-MOP), commonly used in the treatment of psoriasis, binds irreversibly to proteins in the presence of ultraviolet radiation by a mechanism that is not well established. In this paper we demonstrate the photoprotector capacity of three phenolic compounds-pannarin, 1'chloropannarin and atranorin-through the inhibition of 8-MOP-human serum albumin (HSA) photobinding. The method measures the UV-filtering capacity of lichen compounds by means of a double-tube compartment (thus, solubility and interaction with the reaction medium is avoided). Photobinding was determined by measuring the radioactivity of mixtures containing 8-(methyl-3H) MOP and HSA irradiated at 360 and 310 nm in the presence of increasing concentrations of lichen phenolics. Pannarin, l'-chloropannarin and atranorin at a concentration of 10 mM and irradiated at 360 nm, inhibited photobinding to HSA by 40.4%, 31.7% and 20.1% respectively. Pannarin (10 mM) irradiated at 310 nm inhibited the photobinding by 35.2%. The participation of singlet oxygen and hydroxyl radicals was demonstrated in the photoreaction process.
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Affiliation(s)
- E Fernández
- Escuela de Química y Farmacia, Universidad de Valparaíso, Valparaíso, Chile
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20
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Hidalgo ME, Sánchez R, Pérez DG, Rodríguez MA, García J, Orozco E. Molecular characterization of the Entamoeba histolytica enolase gene and modelling of the predicted protein. FEMS Microbiol Lett 1997; 148:123-9. [PMID: 9084139 DOI: 10.1111/j.1574-6968.1997.tb10277.x] [Citation(s) in RCA: 12] [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: 02/04/2023] Open
Abstract
Entamoeba histolytica obtains its energy mainly from glucose fermentation. Enzymes involved in this pathway could be potential targets for antiparasite drugs. Here we report the molecular characterization of the E. histolytica enolase gene (Ehenl-I), which in a single copy is located on the 1.6 Mb chromosome. It is transcribed into a 1.4 kb mRNA which starts 13 nucleotides upstream of the ATG start codon. The sequence TATAAG, at -31, interacted with nuclear proteins suggesting that it has a TATA box function. Protein modelling allowed us to identify a putative specific region that differs from human enolase and could be a good target for the design of novel drugs against E. histolytica.
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Affiliation(s)
- M E Hidalgo
- Departamento de Parología Experimental, Instituto Politécnico Nacional, México, D.F., Mexico
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21
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Fournet A, Ferreira ME, Rojas de Arias A, Torres de Ortiz S, Inchausti A, Yaluff G, Quilhot W, Fernandez E, Hidalgo ME. Activity of compounds isolated from Chilean lichens against experimental cutaneous leishmaniasis. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 1997; 116:51-4. [PMID: 9080673 DOI: 10.1016/s0742-8413(96)00127-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Three secondary metabolites isolated from Chilean lichens, (+) usnic acid, pannarine and 1'-chloropannarine, were tested against promastigotes forms of three strains of Leishmania ssp. Pannarine and 1'-chloropannarine exhibited in vitro activity at 50 micrograms/ml and (+) usnic acid at 25 micrograms/ml. BALB/c mice infected with Leishmania amazonensis were treated 4 weeks post-infection with (+) usnic acid by subcutaneous or oral routes for 15 days at 25 mg/kg or by five intralesional injections at interval of 4 days at 25 mg/kg of body weight. The reference drug, N-methylglucamine antimonate (Glucantime), was administered by subcutaneous injections (regimens of 28 mg of pentavalent antimony) for 15 days. The subcutaneous and oral treatments with (+) usnic did not produce any effect, but by intralesional administration we observed a significant effect that reduced by 43.34% the weight lesions and by 72.28% the parasites loads in infected footpads.
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Affiliation(s)
- A Fournet
- ORSTOM (Institut Français de Recherche Scientifique pour le Développement en Coopération), Asunción, Paraguay.
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Hidalgo ME, Orozco E. Structural characterization of the Entamoeba histolytica enolase gene promoter. Arch Med Res 1997; 28 Spec No:46-8. [PMID: 9033008] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- M E Hidalgo
- Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del I.P.N., México, D.F., Mexico
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23
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Rodríguez MA, Hidalgo ME, Sánchez T, Orozco E. Cloning and characterization of the Entamoeba histolytica pyruvate: ferredoxin oxidoreductase gene. Mol Biochem Parasitol 1996; 78:273-7. [PMID: 8813698 DOI: 10.1016/s0166-6851(96)02613-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- M A Rodríguez
- Departamento de Patología Experimental, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico, D.F. Mexico. dAlvarez@mvaxl.-red.cinvestav.-mx
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24
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Abstract
The antioxidant activity of lichenic metabolites, depsides and depsidones, was assessed by their effects as inhibitors of rat brain homogenate auto-oxidation and beta-carotene oxidation. The results obtained in both systems indicate that lichenic metabolites afford a moderate protection in the microM concentration range. The largest effect was measured employing 1'-chloropannarin in the brain homogenate auto-oxidation, where a 66% protection was afforded at 1.7 microM. This protection is very similar to that elicited by addition of the reference antioxidant propylgallate (70% protection at 1.3 microM).
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Affiliation(s)
- M E Hidalgo
- Escuela de Química y Farmacia, Facultad de Medicina, Universidad de Valparaíso, Chile
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25
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Coura JR, Willcox HP, Tavares AM, de Paiva DD, Fernandes O, Rada EL, Perez EP, Borges LC, Hidalgo ME, Nogueira ML. [Epidemiological, social, and sanitary aspects in an area of the Rio Negro, State of Amazonas, with special reference to intestinal parasites and Chagas' disease]. CAD SAUDE PUBLICA 1994; 10 Suppl 2:327-36. [PMID: 15042222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
A cross-sectional study was carried out on the residents of one in every four dwellings in the town of Barcelos (in the northern part of the State of Amazonas, on the right bank of the Rio Negro, 490 kilometers from Manaus by river), in order to evaluate social and sanitary conditions and specific indicators for intestinal parasites and Chagas' infection. During the survey, two questionnaires were applied, a household one to evaluate social and sanitary aspects, and an individual one, for social and epidemiological evaluation of the population conditions. A conglomerate family sample of 171 dwellings was studied. From each of the 658 habitants, a sample was requested for stool examination by Lutz sedimentation and Baermann-Moraes-Coutinho techniques modified by Willcox & Coura (1989), and blood was collected in filter paper for immunofluorescence test by Camargo (1966) and Souza & Camargo (1966) methods modified by Petana & Willcox (1975). The stool examination showed 69.4% of samples with one or more parasites. Ascaris lumbricoides was predominant with 51% of positivity and Entamoeba histolytica, although surveyed by a non-specific method, was present in 19.7%. Surprisingly, 20.1% of the 658 sera samples were reactive for T. cruzi antibodies at a dilution of 1:20 and 13.7% at 1:40. There was a strong correlation between this result and the level of human contact with wild triatomines, known locally as "piasava lice", and we succeeded in isolating by xenodiagnosis one strain of T. cruzi from one patient, a sixty-one-year old man (n. 209 -1), a native of the area, with positive serology for Chagas' disease and who worked in agriculture and transporting piasava and was very familiar with "piasava lice".
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Affiliation(s)
- J R Coura
- Departamento de Medicina Tropical, Instituto Oswaldo Cruz, Rio de Janeiro, RJ, 21045-900, Brasil
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26
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Abstract
Irradiation of pannarin 1'-chloropannarin and antranorin with 366 nm light leads to significant hemolysis in a red cell suspension. However, their mechanism of action is different. Hemolysis induced by pannarin and 1'chloropannarin increases in the presence of oxygen, whereas hemolysis induced by atranorin is higher in nitrogen-purged solutions. The effect of free radical scavengers, and the lack of effect of D2O in the medium, suggest that the hemolysis induced by pannarin and 1'chloropannarin is not mediated by (1)O2. Both the hemolytic and photohemolytic activities of the depsidones, particularly 1'-chloropannarin, increase when the temperature increases from 21 to 37 degrees C.
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Affiliation(s)
- M E Hidalgo
- Chemistry Department, Faculty of Science, University of Valparaíso Chile
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27
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Cortés MP, Cárdenas AM, Hidalgo ME, Glena C, Fernández E, Sunkel C. New 4-alkyl-1,4-dihydropyridines: evaluation of photostability and phototoxic potential. J Photochem Photobiol B 1993; 19:135-8. [PMID: 8377076 DOI: 10.1016/1011-1344(93)87108-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The photostability and phototoxic potential of two new 4-alkyl-1,4-dihydropyridines (PCA-4230 and PCA-4248) were investigated. When these 4-alkyl-1,4-dihydropyridines were irradiated with a multilamp photoreactor (band centred at 350 nm), both exhibited a slow photodegradation showing first-order kinetics. The photodegradation rate constants were 0.37 h-1 for PCA-4248 and 0.39 h-1 for PCA-4230 in oxygenated conditions. The photodecomposition was slower for both drugs in the absence of oxygen. In order to evaluate the phototoxicity induced by these drugs, red blood cells and Hep-2 (human laringo carcinoma cell line) were irradiated using a minisolarium, which emits UVA radiation (350-390 nm). The results showed that PCA-4248 and PCA-4230 did not exhibit a phototoxic effect in the two models tested.
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Affiliation(s)
- M P Cortés
- Laboratorio de Fotobiología y Fotoquímica, Facultad de Medicina, Universidad de Valparaíso, Chile
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28
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Abstract
The photohaemolytic potentials of the quinolones oxolinic acid, pipemidic acid, rosoxacin, norfloxacin, ciprofloxacin and M-193324 (synthesis intermediary) were evaluated and compared with the photohaemolysis induced by nalidixic acid. Quinolones with a piperazine group in position 7 (pipemidic acid, norfloxacin and ciprofloxacin) did not induce photohaemolysis. However, oxolinic acid, rosoxacin and M-193324 produced a concentration- and oxygen-dependent photohaemolysis. Ascorbic acid, histidine and thiourea inhibited the photohaemolysis induced by oxolinic acid, rosoxacin and M-193324, suggesting a photodynamic mechanism similar to that found with nalidixic acid. In addition, deuterium oxide increased the photohaemolysis induced by photohaemolytic quinolones, indicating that this process is mediated by singlet oxygen.
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Affiliation(s)
- A M Cárdenas
- Laboratorio de Fotobiologia y Fotoquimica, Facultad de Medicina, Universidad de Valparaiso, Chile
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29
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Keene WE, Hidalgo ME, Orozco E, McKerrow JH. Entamoeba histolytica: correlation of the cytopathic effect of virulent trophozoites with secretion of a cysteine proteinase. Exp Parasitol 1990; 71:199-206. [PMID: 2373188 DOI: 10.1016/0014-4894(90)90022-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Work from several laboratories suggests a correlation between expression of cysteine proteinase activity and the cytopathic effect of virulent HM1 strain Entamoeba histolytica trophozoites on cultured cell monolayers. Consistent with this relationship, we find that L-6 trophozoites, mutants cloned from the HM1 parent strain, are deficient in both proteinase expression and cytopathic effect. Three other clones, with proteinase expression equal to or greater than that of the HM1 strain, express the cytopathic effect. Furthermore, a nontoxic specific proteinase inhibitor, Z-phenylalanyl-alanyl-CH2F, inhibits the cytopathic effect of live trophozoites in a dose-dependent manner. These results support the hypothesis that expression and release of the cysteine proteinase is an important factor in producing the cytopathic effect, presumably by its degradation of cell anchoring proteins.
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Affiliation(s)
- W E Keene
- Department of Pathology, University of California, San Francisco 94143
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30
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Hidalgo ME, Ruiz HA, Gömez SC, Hermida MA, Bay MR. [The pharmacist as a member of the medical care team in hospital wards]. Bol Oficina Sanit Panam 1985; 99:395-9. [PMID: 2934075] [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: 01/03/2023]
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