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Silva EF, Gamino M, Oliveira AB, Correa MA, Bohn F. On the nature of the interlayer magnetic interactions in biphase ferromagnetic films. Sci Rep 2023; 13:4409. [PMID: 36932193 PMCID: PMC10023804 DOI: 10.1038/s41598-023-31563-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
We report on the nature of the interlayer magnetic interactions in NiFe/Cu/Co films. By probing the quasi-static and dynamic magnetic properties of biphase ferromagnetic films, with soft and hard ferromagnetic phases intermediated by a non-magnetic layer, we address aspects of the coupling between magnetic layers. Our results demonstrate the nature of the interlayer magnetic coupling in biphase films. We also disclose the asymmetric magnetoimpedance effect as a fingerprint of the nature of the magnetic interlayer interactions playing key role in the magnetization dynamics of the system. We revisit in literature data and ideas on the asymmetric magnetoimpedance and the nature of the magnetic interactions in biphase ferromagnetic systems. Then, we compare our findings with results for biphase ribbons and microwires. Our observations raise the fundamental similarities and differences in the asymmetric magnetoimpedance of these structures.
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Affiliation(s)
- E F Silva
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - M Gamino
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - A B Oliveira
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - M A Correa
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - F Bohn
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil.
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Varela Junior AS, Jardim RD, Streit DP, Cardoso TF, Silva EF, Lucia T, Figuelredo MRC, Corcini CD. Trehalose in extenders for cryopreservation of Tambaqui (Colossoma macropomum) sperm. Cryo Letters 2022; 43:264-268. [PMID: 36626130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Sugars may act as either energy substrates or non-penetrating cryoprotectants. OBJECTIVE Inclusion of non-penetrating trehalose was tested in extenders for the cryopreservation of Tambaqui (Colossoma macropomum) sperm. MATERIALS AND METHODS Sperm was extended 1/9 (v/v) in Beltsville Thawing Solution (BTS) with 10% DMSO (control) or 50, 100, 150 and 200 mM trehalose without 10% DMSO. Post-thawed sperm quality was evaluated, including fertilization and hatching rates, sperm motility, motility period and viability, integrity of sperm membrane and DNA, and mitochondrial functionality. RESULTS Extenders with 100 - 150 mM trehalose achieved fertilization and hatching rates similar to those of the 10% DMSO-treated sperm samples. Trehalose at 100 and 150 mM provides better protection than 10% DMSO treatment for sperm motility, viability, DNA integrity and mitochondrial functionality. Fertilization and hatching rates were highly correlated (r = 0.95, P < 0.001). CONCLUSION The addition of 100 - 150 mM trehalose in extender can replace 10% DMSO for the cryopreservation of C. macropomum sperm. doi.org/10.54680/fr22510110312.
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Affiliation(s)
- A S Varela Junior
- RAC- Reproducao Animal Comparada, Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - R D Jardim
- RAC- Reproducao Animal Comparada, Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - D P Streit
- Aquam, Departamento de Zootecnia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - T F Cardoso
- RAC- Reproducao Animal Comparada, Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - E F Silva
- RAC- Reproducao Animal Comparada, Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - T Lucia
- Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, Brasil
| | - M R C Figuelredo
- ReproPel, Faculdade de Veterinaria, Universidade Federal de Pelotas, Pelotas
| | - C D Corcini
- Instituto de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, Brasil.
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Iglesias CAM, de Araújo JCR, Xavier J, Anders RL, de Araújo JM, da Silva RB, Soares JM, Brito EL, Streck L, Fonseca JLC, Plá Cid CC, Gamino M, Silva EF, Chesman C, Correa MA, de Medeiros SN, Bohn F. Magnetic nanoparticles hyperthermia in a non-adiabatic and radiating process. Sci Rep 2021; 11:11867. [PMID: 34088933 PMCID: PMC8178398 DOI: 10.1038/s41598-021-91334-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/25/2021] [Indexed: 11/17/2022] Open
Abstract
We investigate the magnetic nanoparticles hyperthermia in a non-adiabatic and radiating process through the calorimetric method. Specifically, we propose a theoretical approach to magnetic hyperthermia from a thermodynamic point of view. To test the robustness of the approach, we perform hyperthermia experiments and analyse the thermal behavior of magnetite and magnesium ferrite magnetic nanoparticles dispersed in water submitted to an alternating magnetic field. From our findings, besides estimating the specific loss power value from a non-adiabatic and radiating process, thus enhancing the accuracy in the determination of this quantity, we provide physical meaning to a parameter found in literature that still remained not fully understood, the effective thermal conductance, and bring to light how it can be obtained from experiment. In addition, we show our approach brings a correction to the estimated experimental results for specific loss power and effective thermal conductance, thus demonstrating the importance of the heat loss rate due to the thermal radiation in magnetic hyperthermia.
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Affiliation(s)
- C A M Iglesias
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - J C R de Araújo
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - J Xavier
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - R L Anders
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - J M de Araújo
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - R B da Silva
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - J M Soares
- Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-090, Mossoró, RN, Brazil
| | - E L Brito
- POLYMAT, Departamento de Química Aplicada, Facultad de Ciencias Químicas, University of the Basque Country UPV/EHU, Joxe Mari Korta Zentroa, Tolosa Hiribidea 72, 20018, Donostia-San Sebastián, Spain.,Instituto de Química, Universidade Federal do Rio Grande do Norte, 59078-970, Natal, RN, Brazil
| | - L Streck
- Instituto de Química, Universidade Federal do Rio Grande do Norte, 59078-970, Natal, RN, Brazil.,Curso de Farmácia, Faculdade Maurício de Nassau, 59080-400, Natal, RN, Brazil
| | - J L C Fonseca
- Instituto de Química, Universidade Federal do Rio Grande do Norte, 59078-970, Natal, RN, Brazil
| | - C C Plá Cid
- Departamento de Física, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - M Gamino
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - E F Silva
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - C Chesman
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - M A Correa
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - S N de Medeiros
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil
| | - F Bohn
- Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900, Natal, RN, Brazil.
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Silva EF, Andrade UMS, de Oliveira KM, Teixeira AVNC, Rocha MS. Dodecyltrimethylammonium bromide surfactant effects on DNA: Unraveling the competition between electrostatic and hydrophobic interactions. Phys Rev E 2020; 102:032401. [PMID: 33076016 DOI: 10.1103/physreve.102.032401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 08/16/2020] [Indexed: 01/04/2023]
Abstract
We present a new study on the interaction of the DNA molecule with the surfactant dodecyltrimethylammonium bromide (DTAB), performed mainly with optical tweezers. Single-molecule force spectroscopy experiments performed in the low-force entropic regime allowed a robust characterization of the DNA-DTAB interaction, unveiling how the surfactant changes the mechanical properties of the biopolymer, the binding parameters, and the competition of the two mechanisms involved in the interaction: electrostatic attraction between the cationic surfactant heads and the negative phosphate backbone of the DNA and hydrophobic interactions between the tails of the bound DTAB molecules, which can result in DNA compaction in solution depending on the quantity of bound surfactant. Finally, force clamp experiments with magnetic tweezers and gel electrophoresis assays confirm that DTAB compacts DNA depending not only on the surfactant concentration but also on the conformation of the biopolymer in solution. The present study provides new insights on general aspects of the DNA-surfactant complexes formation, contributing to the fundamental knowledge of the physics of such interactions.
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Affiliation(s)
- E F Silva
- Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil and Departamento de Física, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, 36036-900, Brazil
| | - U M S Andrade
- Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil and Departamento de Formação Geral, Centro Federal de Educação Tecnológica de Minas Gerais, Curvelo, Minas Gerais, 35790-000, Brasil
| | - K M de Oliveira
- Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - A V N C Teixeira
- Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - M S Rocha
- Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
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Caldas JS, Corcini CD, Silva EF, Silva JC, Cardoso TF, Acosta IB, Figueiredo MRC, Varela Junior AS. Liquid Storage of Geophagus brasiliensis semen in the Presence of Different Extenders. Cryo Letters 2020; 41:202-208. [PMID: 33988648] [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: 06/12/2023]
Abstract
BACKGROUND In order to preserve the genetic diversity of cichlid fish in gene banks, it is necessary to use certain extenders to maintain the integrity of spermatozoa cells during cooling. OBJECTIVE To evaluate the effects of different extenders on the quality parameters of cooled semen of Geophagus brasiliensis. MATERIALS AND METHODS Semen samples were collected from seven adult fish and diluted with five extenders: Beltsville Thawing Solution (BTS™), Hanks' Balanced Salt Solution (HBSS), Tris-glucose, Ginsburg's Fish Ringers, and Phosphate buffered Saline. All parameters were evaluated in fresh semen samples and after cooling at 4°C at 0, 24, 48, and 96 h to evaluate cell viability (membrane integrity, DNA, and mitochondrial functionality) and motility rate and weather motility. RESULTS The BTS and Tris-glucose resulted in the best outcomes (P<0.05) in terms of membrane integrity assessments (35.1% and 30.9%, respectively), DNA integrity (71.6%; 75.7%), mitochondrial function (26.9%; 28.0%) and motility rate (8.6%; 8.6%), respectively, for semen cooled to 4°C for 96 h. However, the 48-h period motility after cooling in BTS was superior to all other treatments. CONCLUSION BTS and Tris-glucose can be considered as the best extenders for the cold storage of Geophagus brasiliensis spermatozoa.
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Affiliation(s)
- J S Caldas
- BAAC, Aquatic Environments Continental Biology, Institute of Biological Sciences, Federal University of Rio Grande, Rio Grande, RS, Brazil
| | - C D Corcini
- ReproPel, Faculty of Veterinary Medicine, Campus Capão do Leão, Federal University of Pelotas, Pelotas, Brazil
| | - E F Silva
- RAC - Compared Animal Reproduction, Institute of Biological Sciences, Federal University of Rio Grande, Rio Grande, RS, Brazil
| | - J C Silva
- RAC - Compared Animal Reproduction, Institute of Biological Sciences, Federal University of Rio Grande, Rio Grande, RS, Brazil
| | - T F Cardoso
- RAC - Compared Animal Reproduction, Institute of Biological Sciences, Federal University of Rio Grande, Rio Grande, RS, Brazil
| | - I B Acosta
- ReproPel, Faculty of Veterinary Medicine, Campus Capão do Leão, Federal University of Pelotas, Pelotas, Brazil
| | - M R C Figueiredo
- RAC - Compared Animal Reproduction, Institute of Biological Sciences, Federal University of Rio Grande, Rio Grande, RS, Brazil
| | - A S Varela Junior
- Institute of Biological Sciences, Federal University of Rio Grande, Rio Grande, RS, Brazil.
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Silva EF, Gomes PRB, Fernandes RN, Lyra WS. FLOW-INJECTION SPECTROMETRIC DETERMINATION OF SODIUM DICLOFENAC IN PHARMACEUTICAL FORMULATIONS. J Chil Chem Soc 2018. [DOI: 10.4067/s0717-97072018000203941] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Silva EF, Lima BK, Sena NJC, Sabóia VPA, Feitosa VP. Avaliação do Uso de Alta Intensidade de Luz de LEDs na Odontologia: Revisão de Literatura sobre os Benefícios e Danos. J Health Scie 2018. [DOI: 10.17921/2447-8938.2017v19n5p236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
O objetivo foi avaliar o uso de aparelhos fotopolimerizadores com alta intensidade, analisando os benefícios e os danos. Para tanto, foi realizada uma revisão nos bancos de dados Scielo, BVS, PubMed e Medline utilizando os descritores: fotopolimerização, resina composta e LED. Foram selecionados 10 de um total de 26 artigos publicados entre 2007 e 2017. Para que os compósitos fotoativados sejam polimerizados de forma adequada é essencial que o LED seja capaz de oferecer intensidade de luz suficiente. Esse valor corresponde a uma irradiância mínima de 400 mW/cm² com tempo de 40s. Como os aparelhos de fotopolimerização LEDs disponíveis no mercado são capazes de produzir irradiância de 1600 mW/cm² ou mais, espera-se uma redução no tempo de fotoativação, ocasionando uma grande vantagem tanto para o cirurgião dentista como para o paciente. Entretanto, uma polimerização com intensidade de luz alta e contínua pode causar altas contração de polimerização, levando as tensões na união dente/restauração. Aplicações de irradiâncias cada vez maiores podem gerar calor excessivo e injúrias aos dentes, como o aumento da temperatura pulpar. Em conclusão, mesmo com todas as vantagens que a fotopolimerização proporcionou à Odontologia, questões relacionadas ao estresse de polimerização, aumento de temperatura intrapulpar e confusões sobre o método de aplicação de intensidade de luz persistem atualmente, justificando a necessidade de mais estudos para uma melhor compreensão sobre o funcionamento, aprimoramento do uso e manutenção destes aparelhos na clínica odontológica.Palavras-chave: Fotopolimerização. Resina Composta. LED.
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Rocha JCB, Silva EF, Oliveira MF, Sousa FB, Teixeira AVNC, Rocha MS. β-Cyclodextrin polymer binding to DNA: Modulating the physicochemical parameters. Phys Rev E 2017; 95:052416. [PMID: 28618573 DOI: 10.1103/physreve.95.052416] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Indexed: 11/07/2022]
Abstract
Cyclodextrins and cyclodextrins-modified molecules have interesting and appealing properties due to their capacity to host components that are normally insoluble or poorly soluble in water. In this work, we investigate the interaction of a β-cyclodextrin polymer (poly-β-CD) with λ-DNA. The polymers are obtained by the reaction of β-CD with epichlorohydrin in alkaline conditions. We have used optical tweezers to characterize the changes of the mechanical properties of DNA molecules by increasing the concentration of poly-β-CD in the sample. The physical chemistry of the interaction is then deduced from these measurements by using a recently developed quenched-disorder statistical model. It is shown that the contour length of the DNA does not change in the whole range of poly-β-CD concentration (<300μM). On the other hand, significant alterations were observed in the persistence length that identifies two binding modes corresponding to the clustering of ∼2.6 and ∼14 polymer molecules along the DNA double helix, depending on the polymer concentration. Comparing these results with the ones obtained for monomeric β-CD, it was observed that the concentration of CD that alters the DNA persistence length is considerably smaller when in the polymeric form. Also, the binding constant of the polymer-DNA interaction is three orders of magnitude higher than the one found for native (monomeric) β-CD. These results show that the polymerization of the β-CD strongly increases its binding affinity to the DNA molecule. This property can be wisely used to modulate the binding of cyclodextrins to the DNA double helix.
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Affiliation(s)
- J C B Rocha
- Departamento de Física, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil.,Instituto Federal do Norte de Minas Gerais-Campus Avançado Janaúba, 39440-000 Janaúba, MG, Brazil
| | - E F Silva
- Departamento de Física, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil
| | - M F Oliveira
- Departamento de Química, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
| | - F B Sousa
- Instituto de Física e Química, Universidade Federal de Itajubá, 37500-903 Itajubá, MG, Brazil
| | - A V N C Teixeira
- Departamento de Física, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil
| | - M S Rocha
- Departamento de Física, Universidade Federal de Viçosa, 36570-900 Viçosa, MG, Brazil
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Dos Santos Moreira MC, Naves LM, Marques SM, Silva EF, Rebelo AC, Colombari E, Pedrino GR. Neuronal circuits involved in osmotic challenges. Physiol Res 2017; 66:411-423. [PMID: 28248529 DOI: 10.33549/physiolres.933373] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The maintenance of plasma sodium concentration within a narrow limit is crucial to life. When it differs from normal physiological patterns, several mechanisms are activated in order to restore body fluid homeostasis. Such mechanisms may be vegetative and/or behavioral, and several regions of the central nervous system (CNS) are involved in their triggering. Some of these are responsible for sensory pathways that perceive a disturbance of the body fluid homeostasis and transmit information to other regions. These regions, in turn, initiate adequate adjustments in order to restore homeostasis. The main cardiovascular and autonomic responses to a change in plasma sodium concentration are: i) changes in arterial blood pressure and heart rate; ii) changes in sympathetic activity to the renal system in order to ensure adequate renal sodium excretion/absorption, and iii) the secretion of compounds involved in sodium ion homeostasis (ANP, Ang-II, and ADH, for example). Due to their cardiovascular effects, hypertonic saline solutions have been used to promote resuscitation in hemorrhagic patients, thereby increasing survival rates following trauma. In the present review, we expose and discuss the role of several CNS regions involved in body fluid homeostasis and the effects of acute and chronic hyperosmotic challenges.
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Affiliation(s)
- M C Dos Santos Moreira
- Department of Physiological Science, Federal University of Goiás, Goiânia - GO - Brazil. or
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Silva EF, Bazoni RF, Ramos EB, Rocha MS. DNA-doxorubicin interaction: New insights and peculiarities. Biopolymers 2017; 107. [PMID: 27718222 DOI: 10.1002/bip.22998] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [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: 06/15/2016] [Revised: 09/25/2016] [Accepted: 10/05/2016] [Indexed: 12/18/2022]
Abstract
We have investigated the interaction of the DNA molecule with the anticancer drug doxorubicin (doxo) by using three different experimental techniques: single molecule stretching, single molecule imaging, and dynamic light scattering. Such techniques allowed us to get new insights on the mechanical behavior of the DNA-doxo complexes as well as on the physical chemistry of the interaction. First, the contour length data obtained from single molecule stretching were used to extract the physicochemical parameters of the DNA-doxo interaction under different buffer conditions. This analysis has proven that the physical chemistry of such interaction can be modulated by changing the ionic strength of the surrounding buffer. In particular we have found that at low ionc strengths doxo interacts with DNA by simple intercalation (no aggregation) and/or by forming bound dimers. For high ionic strengths, otherwise, doxo-doxo self-association is enhanced, giving rise to the formation of bound doxo aggregates composed by 3 to 4 molecules along the double-helix. On the other hand, the results obtained for the persistence length of the DNA-doxo complexes is strongly force-dependent, presenting different behaviors when measured with stretching or non-stretching techniques.
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Affiliation(s)
- E F Silva
- Laboratório de Física Biológica, Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - R F Bazoni
- Laboratório de Física Biológica, Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - E B Ramos
- Laboratório de Física Biológica, Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - M S Rocha
- Laboratório de Física Biológica, Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
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Silva AC, Varela AS, Cardoso TF, Silva EF, Loebmann D, Corcini CD. Evaluation of sperm quality of Erythrolamprus poecilogyrus sublineatus (Cope, 1860) (Serpentes, Dipsadidae). BRAZ J BIOL 2017; 77:553-557. [PMID: 28099575 DOI: 10.1590/1519-6984.19215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 05/12/2016] [Indexed: 11/22/2022] Open
Abstract
Erythrolamprus poecilogyrus sublineatus (Cope, 1860), is a species widely distributed in the Pampa Domain, occurring in Rio Grande do Sul, Argentina and Uruguay, mainlyin the pampa region. In the coastal region of southern Brazil this is serpent is considered one of the most abundant. The purpose of the present study is to describe the techniques of sperm evaluation in vitro for E. poecilogyrus sublineatus in the coastal plain of Rio Grande do Sul, Brazil. After laparatomy the efferent vases were collected and the semen was diluted in 1ml Beltsville Thawing Solution. The characteristics of motility, membrane integrity, mitochondria, acrosome, DNA, cell viability and cellular functionality were evaluated. Fluorescent probes were used for the evaluation of sperm structure in epifluorescence microscope. With the techniques described, it was possible to identify intact and injured cells, enabling the determination of cell characteristics for the spring season (October and November). It was observed in the analyses that 80% of sperm cells were mobile and that 84.1 ± 8.0% of sperm membranes were intact. The standards found were of 48 ± 13.8% of intact acrosome, 73.6 ± 6.0 of perfect DNA and of 91.8 ± 4.0 of functional mitochondria. Thus, these values from the sperm analysis can be used as standards for the species Erythrolamprus poecilogyrus sublineatus.
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Affiliation(s)
- A C Silva
- Center for Research and Education in Animal Reproduction, Faculdade de Veterinária, Universidade Federal de Pelotas - UFPel, Campus Universitário, s/n, CEP 96160-000, Capão do Leão, RS, Brazil
| | - A S Varela
- Institute of Biological Sciences, Universidade Federal do Rio Grande - FURG, Campus Carreiros, Av. Itália, Km 8, Bairro Carreiros, CEP 96203-900, Rio Grande, RS, Brazil
| | - T F Cardoso
- Institute of Biological Sciences, Universidade Federal do Rio Grande - FURG, Campus Carreiros, Av. Itália, Km 8, Bairro Carreiros, CEP 96203-900, Rio Grande, RS, Brazil
| | - E F Silva
- Institute of Biological Sciences, Universidade Federal do Rio Grande - FURG, Campus Carreiros, Av. Itália, Km 8, Bairro Carreiros, CEP 96203-900, Rio Grande, RS, Brazil
| | - D Loebmann
- Institute of Biological Sciences, Universidade Federal do Rio Grande - FURG, Campus Carreiros, Av. Itália, Km 8, Bairro Carreiros, CEP 96203-900, Rio Grande, RS, Brazil
| | - C D Corcini
- Center for Research and Education in Animal Reproduction, Faculdade de Veterinária, Universidade Federal de Pelotas - UFPel, Campus Universitário, s/n, CEP 96160-000, Capão do Leão, RS, Brazil
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Gastal GDA, Silva EF, Mion B, Varela Junior AS, Rosa CE, Corcini CD, Mondadori RG, Vieira AD, Bianchi I, Lucia T. Antioxidant Effect of Xanthan Gum on Ram Sperm after Freezing and Thawing. Cryo Letters 2017; 38:187-193. [PMID: 28767741] [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: 06/07/2023]
Abstract
BACKGROUND Xanthan gum is used as thickener in media to preserve food products, having cryoprotectant and antioxidant properties that may be relevant for sperm cryopreservation. OBJECTIVE To evaluate the effects of adding xanthan gum to freezing extenders on post-thawing quality and oxidant activity of ram sperm. METHODS Ejaculates from seven rams extended TRIS-egg yolk-glycerol were split in three treatments including xanthan gum (0.15%; 0.20%; and 0.25%) and a control with no xanthan gum. RESULTS After thawing, motility and production of reactive oxygen species (ROS) with 0.20% and 0.25% xanthan gum were lower than for the control (P < 0.05), but mitochondrial functionality and integrity of membrane, acrosome and DNA did not differ (P > 0.05). Xanthan gum at 0.20% and 0.25% may be an efficient antioxidant for frozen-thawed ram sperm, due to the reduction in ROS production.
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Affiliation(s)
- G DA Gastal
- ReproPel, Faculdade de Veterinaria, Universidade Federal de Pelotas, Pelotas-RS, Brazil
| | - E F Silva
- ReproPel, Centro de Biotecnologia, Universidade Federal de Pelotas, Pelotas-RS, Brazil
| | - B Mion
- ReproPel,Faculdade de Veterinaria, Universidade Federal de Pelotas, Pelotas-RS, Brazil
| | - A S Varela Junior
- ReproPel, Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande, Rio Grande-RS, Brazil
| | - C E Rosa
- Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande, Rio Grande-RS, Brazil
| | - C D Corcini
- ReproPel, Faculdade de Veterinaria, Universidade Federal de Pelotas, Pelotas-RS, Brazil
| | - R G Mondadori
- ReproPel, Instituto de Biologia, Universidade Federal de Pelotas, Pelotas-RS, Brazil
| | - A D Vieira
- ReproPel, Faculdade de Veterinaria, Universidade Federal de Pelotas, Pelotas-RS, Brazil
| | - I Bianchi
- ReproPel, Faculdade de Veterinaria, Universidade Federal de Pelotas, Pelotas-RS, Brazil
| | - T Lucia
- ReproPel, Faculdade de Veterinaria, Universidade Federal de Pelotas, Pelotas-RS, Brazil.
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13
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Silva EF, Moreira M, R Manzano MA, Blanco R. Case study of permeability-reducing admixture use in anti-flotation slabs: building in Brasilia, Brazil. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s41024-016-0014-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Tejada TS, Silva CSJ, Lopes NA, Silva DT, Agostinetto A, Silva EF, Menezes DB, Timm CD. DNA Profiles of Salmonella Spp. Isolated from Chicken Products and From Broiler and Human Feces. Rev Bras Cienc Avic 2016. [DOI: 10.1590/1806-9061-2016-0316] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- TS Tejada
- Universidade Federal de Pelotas, Brazil
| | - CSJ Silva
- Universidade Federal de Pelotas, Brazil
| | - NA Lopes
- Universidade Federal de Pelotas, Brazil
| | - DT Silva
- Universidade Federal de Pelotas, Brazil
| | | | - EF Silva
- Universidade Federal de Pelotas, Brazil
| | | | - CD Timm
- Universidade Federal de Pelotas, Brazil
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15
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Souza LS, Silva EF, Santos WB, Asth L, Lobão-Soares B, Soares-Rachetti VP, Medeiros IU, Gavioli EC. Lithium and valproate prevent methylphenidate-induced mania-like behaviors in the hole board test. Neurosci Lett 2016; 629:143-148. [PMID: 27353513 DOI: 10.1016/j.neulet.2016.06.044] [Citation(s) in RCA: 10] [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] [Received: 04/22/2016] [Revised: 06/21/2016] [Accepted: 06/22/2016] [Indexed: 12/21/2022]
Abstract
Manic bipolar is diagnosed by psychomotor agitation, increased goal-directed activity, insomnia, grandiosity, excessive speech, and risky behavior. Animal studies aimed to modeling mania are commonly based in psychostimulants-induced hyperlocomotion. The exploration of other behaviors related with mania is mandatory to investigate this phase of bipolar disorder in animals. In this study, the hole board apparatus was suggested for evaluating mania-like behaviors induced by the psychostimulant methylphenidate. The treatment with methylphenidate (10mg/kg, ip) increased locomotion in the open field test. The pretreatment with lithium (50mg/kg, ip) and valproate (400mg/kg, ip) significantly prevented the hyperlocomotion. In the hole-board test, methylphenidate increased interactions with the central and peripheral holes and the exploration of central areas. Lithium was more effective than valproate in preventing all the behavioral manifestations induced by the psychostimulant. These findings were discussed based on the ability of methylphenidate-treated mice mimicking two symptoms of mania in the hole board test: goal-directed action and risk-taking behavior. In conclusion, the results point to a new approach to study mania through the hole board apparatus. The hole board test appears to be a sensitive assay to detect the efficacy of antimanic drugs.
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Affiliation(s)
- L S Souza
- Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - E F Silva
- Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - W B Santos
- Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - L Asth
- Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - B Lobão-Soares
- Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - V P Soares-Rachetti
- Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - I U Medeiros
- Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil
| | - E C Gavioli
- Behavioral Pharmacology Laboratory, Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
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16
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Bernal WFP, Silva EF, Rocha MS. Unraveling the physical chemistry and the mixed binding modes of complex DNA ligands by single molecule stretching experiments. RSC Adv 2016. [DOI: 10.1039/c6ra22980h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
In this work we present a complete methodology to unravel the physical chemistry and the mixed binding modes of complex DNA ligands.
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Affiliation(s)
- W. F. P. Bernal
- Laboratório de Física Biológica
- Departamento de Física
- Universidade Federal de Viçosa
- Viçosa
- Brazil
| | - E. F. Silva
- Laboratório de Física Biológica
- Departamento de Física
- Universidade Federal de Viçosa
- Viçosa
- Brazil
| | - M. S. Rocha
- Laboratório de Física Biológica
- Departamento de Física
- Universidade Federal de Viçosa
- Viçosa
- Brazil
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17
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Lorenzi W, Goncalves FDC, Schneider N, Silva EF, Paz AHDR, Saueressig MG. 288 * EFFECT OF REPEATED ADMINISTRATION OF ADIPOCYTE-DERIVED MESENCHYMAL STEM CELLS ON A MURINE MODEL OF BRONCHIOLITIS OBLITERANS. Interact Cardiovasc Thorac Surg 2014. [DOI: 10.1093/icvts/ivu276.288] [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: 11/14/2022] Open
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18
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Siqueira MVBM, Nascimento WF, Silva LRG, Ferreira AB, Silva EF, Ming LC, Veasey EA. Distribution, management and diversity of yam local varieties in Brazil: a study on Dioscorea alata L. BRAZ J BIOL 2014; 74:52-61. [PMID: 25055086 DOI: 10.1590/1519-6984.17112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 12/18/2012] [Indexed: 11/22/2022] Open
Abstract
Widely spread in the tropics, yams were introduced into Brazil during the colonial period and are currently grown throughout the country. Despite its importance as a pharmacological and food source, there is a lack of studies describing how and where this tuber is grown in Brazil. The aim of this study was to provide an overview of the cultivation and distribution of Dioscorea alata in different Brazilian regions. A total of 63 farmers were visited in different municipalities and communities in four regions in the country: South, Southeast, Northeast and Midwest. Semi-structured interviews were conducted to collect socio-economic, use, management and diversity data for this crop. The majority of interviewers were men, married, with children, using retirement benefits and agriculture as income and family labour as the main support in the yam cultivation. A wide distribution of this species was found, with the occurrence of D. alata in the four sampled regions. A variety of vernacular names for this species was collected, differing according to the region where it is cultivated. Most farmers cultivate yams in fields, however an increased usage of home gardens for the cultivation of this tuber was found. Also, most farmers cultivate yams in association with other crops in areas of different sizes and slash and burn practices, although mostly disappearing, are still being used by many farmers. The results of this study provide more concrete data on the distribution and diversity of this important crop.
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Affiliation(s)
- M V B M Siqueira
- Central de Laboratórios de Pesquisa, Ciência e Tecnologia Ambiental, Universidade Sagrado Coração, Bauru, SP, Brazil
| | - W F Nascimento
- Departamento de Genética, Escola Superior de Agricultura ?Luiz de Queiroz? ? ESALQ, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - L R G Silva
- Departamento de Genética, Escola Superior de Agricultura ?Luiz de Queiroz? ? ESALQ, Universidade de São Paulo, Piracicaba, SP, Brazil
| | - A B Ferreira
- Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - E F Silva
- Departamento de Biologia, Universidade Federal Rural de Pernambuco, Recife, PE, Brazil
| | - L C Ming
- Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP, Brazil
| | - E A Veasey
- Departamento de Genética, Escola Superior de Agricultura ?Luiz de Queiroz? ? ESALQ, Universidade de São Paulo, Piracicaba, SP, Brazil
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Moraes Filho RM, Martins LSS, Musser RS, Montarroyos AVV, Silva EF. Genetic variability in accessions of the acerola germplasm bank of Universidade Federal Rural de Pernambuco, Brazil. Genet Mol Res 2013; 12:5145-51. [PMID: 24301774 DOI: 10.4238/2013.october.29.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Brazil is the world's largest producer of acerola, Malpighia emarginata (Malpighiaceae); the Northeast is responsible for 60% of the national production. The culture of acerola in Brazil has great genetic variability; plantings have high phenotypic diversity and are not very productive, often originating from propagation by seed. We evaluated the genetic diversity of 42 accessions from the Acerola Active Germplasm Bank of Universidade Federal de Pernambuco. Using 15 RAPD primers, 182 markers were obtained, of which 166 were polymorphic and 16 were monomorphic. We found high genetic variability among the accessions (ĤE = 0.29), with no redundancy. Considering the accessions from the states of Pernambuco, Bahia and Pará as distinct groups, there was greater diversity in accessions from Bahia than from the other two states.
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Affiliation(s)
- R M Moraes Filho
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brasil
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20
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Vilela J, Hartmann A, Silva EF, Cardoso T, Corcini CD, Varela-Junior AS, Martinez PE, Colares EP. Sperm impairments in adult vesper mice (Calomys laucha) caused byin uteroexposure to bisphenol A. Andrologia 2013; 46:971-8. [DOI: 10.1111/and.12182] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2013] [Indexed: 11/27/2022] Open
Affiliation(s)
- J. Vilela
- Instituto de Ciências Biológicas; Universidade Federal do Rio Grande (FURG); Rio Grande RS Brazil
| | - A. Hartmann
- Instituto de Ciências Biológicas; Universidade Federal do Rio Grande (FURG); Rio Grande RS Brazil
| | - E. F. Silva
- ReproPel; Faculdade de Veterinária; Campus Capão do Leão; Universidade Federal de Pelotas (UFPel); Pelotas RS Brazil
| | - T. Cardoso
- Instituto de Ciências Biológicas; Universidade Federal do Rio Grande (FURG); Rio Grande RS Brazil
| | - C. D. Corcini
- Instituto de Ciências Biológicas; Universidade Federal do Rio Grande (FURG); Rio Grande RS Brazil
- ReproPel; Faculdade de Veterinária; Campus Capão do Leão; Universidade Federal de Pelotas (UFPel); Pelotas RS Brazil
| | - A. S. Varela-Junior
- Instituto de Ciências Biológicas; Universidade Federal do Rio Grande (FURG); Rio Grande RS Brazil
| | - P. E. Martinez
- Instituto de Ciências Biológicas; Universidade Federal do Rio Grande (FURG); Rio Grande RS Brazil
| | - E. P. Colares
- Instituto de Ciências Biológicas; Universidade Federal do Rio Grande (FURG); Rio Grande RS Brazil
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21
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Cardoso TF, Varela AS, Silva EF, Vilela J, Hartmann A, Jardim RD, Colares EP, Corcini CD. Influence of mineral, olive or sunflower oils on male reproductive parameters in vitro--the wild rodent Calomys laucha. Andrologia 2013; 46:722-5. [PMID: 23889566 DOI: 10.1111/and.12138] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2013] [Indexed: 11/30/2022] Open
Abstract
The aim of this study was to evaluate the influence of oils on male reproductive parameters in Calomys laucha. Twenty-four animals were distributed into four groups and given the following substances by gavage: water, mineral oil, olive oil and sunflower oil. After 10 days of gavage, the animals were euthanised and the semen was collected from them for assessing acrosome integrity and carrying out in vitro penetration (IVP) test. Acrosome was significantly reduced (P < 0.05) for the vehicles in relation to control. In vitro penetration was reduced in all vehicles in relation to control, but only sunflower oil had statistically lower levels of reduction (P < 0.05). Oily vehicles are able to influence in vitro reproductive tests negatively, interfering in reproductive toxicological studies.
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Affiliation(s)
- T F Cardoso
- ReproPel, Faculdade de Veterinária, Campus Capão do Leão, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil
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22
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Silva EF, Ramos EB, Rocha MS. DNA Interaction with Hoechst 33258: Stretching Experiments Decouple the Different Binding Modes. J Phys Chem B 2013; 117:7292-6. [DOI: 10.1021/jp403945e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- E. F. Silva
- Laboratório de Física
Biológica,
Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - E. B. Ramos
- Laboratório de Física
Biológica,
Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - M. S. Rocha
- Laboratório de Física
Biológica,
Departamento de Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
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23
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Marques BLC, Brandão CU, Silva EF, Marques VA, Villela-Nogueira CA, Do Ó KMR, de Paula MT, Lewis-Ximenez LL, Lampe E, Villar LM. Dried blood spot samples: optimization of commercial EIAs for hepatitis C antibody detection and stability under different storage conditions. J Med Virol 2013; 84:1600-7. [PMID: 22930508 DOI: 10.1002/jmv.23379] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This study was undertaken to optimize and compare the efficiency of two commercial EIAs for anti-HCV detection (HCV Ab Radim, Pomezzia, Italy and ETI-AB-HCVK-4 DiaSorin, Vercelli, Italy), in dried blood spot (DBS) samples. The long-term stability of anti-HCV on DBS samples stored at three environmental conditions was also evaluated at: 2-8 °C, 20-25 °C, and -20 °C. Paired DBS and serum samples were obtained from individuals with or without anti-HCV. The type of elution buffer, sample and conjugate volume, sample incubation time and cut-off values were evaluated. For both EIAs, a larger sample volume was used, and the cut-off value determined by the manufacturer was employed for Radim EIA; however, ROC curve analysis was used for the DiaSorin EIA. The sensitivity and specificity of Radim EIA on DBS were 97.5% and 99.5%, respectively, and of DiaSorin EIA were 88.9% and 98.9%, respectively. Accurate results were obtained for a period of 117 days using DBS samples stored at all storage conditions, but storage at -20 °C resulted in the lowest variation among the absorbance values. Both EIAs demonstrated the same limit of detection (until dilution of 1:10(4) with estimated viral load of 3.1 × 10(-1) UI/ml), but the Radim EIA was associated with the best performance because a low coefficient of variation was observed in the repetition and reproducibility studies. In conclusion, commercial EIAs can be optimized for anti-HCV detection in DBS samples that are extremely stable at different conditions for more than 100 days.
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Affiliation(s)
- B L C Marques
- Laboratory of Viral Hepatitis, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil
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Potsch DV, Camacho LAB, Tuboi S, Villar LM, Miguel JC, Ginuíno C, Silva EF, Mendonça RMM, Moreira RB, Barroso PF. Vaccination against hepatitis B with 4-double doses increases response rates and antibodies titers in HIV-infected adults. Vaccine 2012; 30:5973-7. [PMID: 22828589 DOI: 10.1016/j.vaccine.2012.07.028] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/05/2012] [Accepted: 07/12/2012] [Indexed: 11/25/2022]
Abstract
BACKGROUND Antibody responses to standard regimens of hepatitis B (HBV) vaccination are lower in HIV-infected subjects and the best hepatitis B vaccine schedule in this population is not known. OBJECTIVE To assess the immunogenicity and to evaluate predictors of serologic response of a modified regimen of a HBV recombinant vaccine in a cohort of HIV-infected subjects. METHODS HIV-infected subjects received 4 doses (40 μg) of a recombinant HBV vaccine at 0, 1, 2 and 6 months. Demographic information as well as CD4 cell count and plasma viral load were assessed at baseline. Protective and strong responses were defined as an anti-HBs titer ≥10 mIU/mL and ≥100 mIU/mL, respectively and were evaluated one month after the third and the fourth doses. RESULTS 163 HIV-infected individuals were evaluated 67 (40%) were male and median age was 37 years. Median CD4 cell count was 385 cells/mm(3) and 113 (70%) had undetectable HIV-1 viral load. Protective antibody response was observed in 83 and 91% and a strong antibody response was observed in 62 and 80% of the subjects after 3 and 4 doses, respectively. In a multivariate logistic model undetectable HIV-1 viral load and higher CD4 cell counts were independent predictors of a strong antibody response after 4 doses. Patients with undetectable HIV viral load were almost 3 times more likely to have anti-HBs titers above 100 mIU/mL than those with detectable viral load. CONCLUSIONS A 4-double-dose regimen of a recombinant HBV vaccine increased response rates and determined higher antibody titers which may translate in prolonged protection against HBV. Inclusion of a fourth dose of HBV vaccine for HIV-infected subjects should be considered in the public health setting.
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Affiliation(s)
- D V Potsch
- HUCFF/FM - Universidade Federal do Rio de Janeiro, Brazil.
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25
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Oliveira MS, Muzzi RAL, Araújo RB, Muzzi LAL, Ferreira DF, Nogueira R, Silva EF. Heart rate variability parameters of myxomatous mitral valve disease in dogs with and without heart failure obtained using 24-hour Holter electrocardiography. Vet Rec 2012; 170:622. [PMID: 22645158 DOI: 10.1136/vr.100202] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Time-domain heart rate variability (HRV) parameters and the correlation between echocardiography and Holter examinations in dogs with myxomatous mitral valve disease (MMVD) were determined. Holter examination was also performed at different time frames: an entire 24-hour period, a four-hour period during sleep, and a four-hour period while awake. Ten healthy (control group) and 28 MMVD dogs, 15 with and 13 without heart failure, were evaluated. The SDANN (sd of the mean normal RR intervals for all five-minute segments during 24-hour Holter) and pNN(50) (percentage of differences between adjacent normal RR intervals that are >50 ms computed over 24-hour Holter) variables were significantly lower in the dogs with MMVD heart failure. The differences in HRV between the groups were only detected during the 24-hour evaluation period (P<0.05). There were high correlations (canonical analysis) between Holter and echocardiography examinations when considering pNN(50), SDANN, and LA/AO (left atrial to aortic root ratio) (r=0.92; P<0.05), indicating that both are important in evaluating MMVD dogs. SDANN and pNN(50) are measures of parasympathetic control of the heart, and thus, it is possible to infer that the MMVD dogs exhibit parasympathetic withdrawal during the development of heart failure.
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Affiliation(s)
- M S Oliveira
- Departamento de Clínica e Cirurgia Veterinária, Escola de Veterinária, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brasil.
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Borboleta LR, Silva EF, Oliveira MS, Michel AFRM, Ferraz VP, Leite RC, Melo MM. Cardiac evaluation after experimental intoxication by Amorimia rigida (Malpighiaceae) extracts in rabbits. J Venom Anim Toxins Incl Trop Dis 2012. [DOI: 10.1590/s1678-91992012000300007] [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: 11/22/2022] Open
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27
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Potsch DV, Oliveira MLA, Ginuíno C, Miguel JC, Oliveira SAN, Silva EF, Moreira RB, Cruz GVM, Oliveira ALVSM, Camacho LAB, Barroso PF. High rates of serological response to a modified hepatitis B vaccination schedule in HIV-infected adults subjects. Vaccine 2009; 28:1447-50. [PMID: 19995540 DOI: 10.1016/j.vaccine.2009.11.066] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 11/11/2009] [Accepted: 11/20/2009] [Indexed: 12/14/2022]
Abstract
We evaluated a modified HBV regimen in a cohort of HIV-infected subjects in Rio de Janeiro, Brazil. HIV-infected subjects with no serologic evidences of previous hepatitis B infection were immunized with 4 doses (40 microg each) of recombinant hepatitis B vaccine given at 0, 1, 2 and 6 months. Blood samples were collected 1 month after the last dose and anti-HBs titers were measured. A protective antibody response was defined as an anti-HBs titer >or=10 mIU/mL. Forty-seven subjects (30 women, 17 men; mean age was 36 years, ranging from 21 to 58 years) were included in the final analysis. Median baseline CD4+ lymphocyte count was 402 cells/mm(3) and 33 subjects (70%) had an HIV viral load below 80 copies/mL. A protective antibody response was observed in 42 (89%) subjects. Thirty-seven (78%) and 28 (60%) patients developed anti-HBs titers higher than 100 mIU/mL and 1000 mIU/mL, respectively. 1 out of 5 non-responders (20%) had an HIV viral load below the detection limit, in contrast with 32 (76%) of those with an adequate serologic response (p=0.02). These findings suggest that 4-double dose alternative schedule may be considered to overcome the lower seroconversion rates observed with the standard regimens in HIV-infected subjects.
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Affiliation(s)
- D V Potsch
- Adult Vaccination Center, School of Medicine, Universidade Federal do Rio de Janeiro, Brazil.
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Lima ZP, Calvo TR, Silva EF, Pellizzon CH, Vilegas W, Brito ARMS, Bauab TM, Hiruma-Lima CA. Brazilian medicinal plant acts on prostaglandin level and Helicobacter pylori. J Med Food 2009; 11:701-8. [PMID: 19053863 DOI: 10.1089/jmf.2007.0676] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Among the current treatment strategies for the peptic ulcer patient with Helicobacter pylori infection, the method of choice is triple therapy based on the concurrent use of proton inhibitors and two antibiotics. Alchornea triplinervia is a medicinal plant commonly used by people living in the Cerrado region of Brazil to treat gastrointestinal ulcers. In the present work we proposed therapy based on this medicinal plant that presents effective gastroprotective action with antibiotic effects. Oral pretreatment with methanolic extract (ME) of A. triplinervia in rats and mice decreased the gastric injuries induced by ethanol and HCl/ethanol. Increasing the dose reduced the gastroprotective effects of ME on the gastric lesions induced by nonsteroidal anti-inflammatory drug. After pylorus ligature of mice, oral administration of ME induced a decrease not only in total acid but also in the ulcer index. We also observed that ME displayed antibacterial activity against H. pylori. Liquid-liquid separation of ME indicated that active constituents responsible for the gastroprotective action are concentrated in the ethyl acetate fraction (EAF) (50% protection) rather than in the aqueous fraction, which did not induce significant gastroprotection at the same dose (100 mg/kg). EAF induced an increase of gastric mucosa prostaglandin (PG) E(2) levels, which remained high even after previous administration of indomethacin. The phytochemical profile of ME revealed that EAF contains mainly flavonoids. In conclusion, all these results suggest that ME did not show acute toxicity, but exhibited an antisecretory property, anti-H. pylori effect, and gastroprotective action. The observed effect did not involve the participation of nitric oxide or endogenous sulfhydryl groups. However, EAF showed a more efficient gastroprotective effect than ME at a lower dose and protected the gastric mucosa by increasing PGE(2).
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Affiliation(s)
- Z P Lima
- Departamentos de Fisiologia, São Paulo State University, Botucatu, Brazil
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29
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Lima CS, Lourenço GJ, Angelo SN, Honma HN, Silva EF, Nascimento H, Cardoso-Filho C, Ortega MM, Sagarra AF, Costa FF. An analysis of the GST genetic polymorphism in cancer risk in Southeastern Brazil. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.22053] [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: 11/20/2022] Open
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30
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Angelo SN, Yamaguti GG, Lourenço GJ, Honma HN, Silva EF, Sagarra AF, Coy CS, Correa ME, Jorge-Junior J, Lima CS. The role of the CYP1A1 gene defects in cancer risk in south-eastern Brazil. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.22115] [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: 11/20/2022] Open
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31
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Silva OA, Silva PB, Silva OV, Braga GM, Albuquerque Júnior A, Queiros Neto V, Rocha ME, Silva EF. [Canine visceral leishmaniasis in northeast Brazil: epidemiological aspects]. Bull Soc Pathol Exot 2007; 100:49-50. [PMID: 17402696] [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: 05/14/2023]
Abstract
In a rural area of Northeast Brazil, the relatively high serological infection by Leishmania in dogs, the lack of classical vector Lutzomyia longipalpis and of American Visceral Leishmaniasis cases in human beings and the observation of Leishmania in ticks collected in infected dogs suggest that ticks may be responsible for the transmission between dogs.
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Affiliation(s)
- O A Silva
- Département de parasitologie, Centre de recherche Aggeu Magalhães/Fiocruz, Pernambouco, Brésil
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32
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Benetton MLFN, Gonçalves AV, Meneghini MEF, Silva EF, Carneiro M. Risk factors for infection by the Entamoeba histolytica/E. dispar complex: An epidemiological study conducted in outpatient clinics in the city of Manaus, Amazon Region, Brazil. Trans R Soc Trop Med Hyg 2005; 99:532-40. [PMID: 15869773 DOI: 10.1016/j.trstmh.2004.11.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [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: 08/13/2004] [Revised: 11/22/2004] [Accepted: 11/29/2004] [Indexed: 10/25/2022] Open
Abstract
An epidemiological study was conducted on a population attending outpatient clinics in Manaus, Amazon, Brazil to determine the prevalences of infection by the Entamoeba histolytica/E. dispar complex and by E. histolytica alone, as well as to identify the risk factors involved in transmission. The study was conducted in two phases: survey and case-control. Face-to-face interviews were carried out and faecal samples collected from 1578 individuals. Faeces were examined by optical microscopy and tested for the pathogenic E. histolytica specific antigen. Positivity to E. histolytica/E. dispar was 21.5% (340 cases). Cases were compared with 340 control samples, negative for the E. histolytica/E. dispar complex based on examination by optical microscopy. The analysis was conducted by logistic regression. The risk factors identified were: place of residence, age, ingestion of raw vegetables, quality of water consumed, number of rooms and bedrooms per house, and having other protozoan infections. Specific antigen detection tests identified 22 participants infected by E. histolytica (6.8%) among those positive for E. histolytica/E. dispar. There was a higher proportion of males among participants infected by E. histolytica than among those with E. dispar infections. The study population was asymptomatic or presented non-specific symptoms that could be attributed to amoebiasis.
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Affiliation(s)
- M L F N Benetton
- Departamento de Parasitologia, Universidade Federal do Amazonas, Manaus, AM, Brazil
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33
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Abstract
Among the many initiating events that lead to apoptosis or programmed cell death, loss of contact between the cell and the extracellular matrix has been extensively studied. Adhesion-related apoptosis referred to as anoikis is initiated by the action of anti-adhesive substances. Nitric oxide is one of these anti-adhesive substances that have the capacity to signal and trigger pro-apoptotic events in a variety of cell types. Nitric oxide can inhibit cell adhesion, interfere with the assembly of focal adhesion complexes, and disrupt the cell-extracellular matrix interactions. These actions occur in cell that exhibit a dissociation of growth factor signals from alterations in the cytoskeleton, ultimately leading to apoptosis. Since this involves anti-adhesive events, nitric oxide can be considered as causing anoikis. This review article summarizes the available evidence of how nitric oxide participates in apoptosis induced by loss of anchorage (anoikis).
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Affiliation(s)
- H P Monteiro
- Department of Biochemistry, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
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Senff-Ribeiro A, Echevarria A, Silva EF, Franco CRC, Veiga SS, Oliveira MBM. Cytotoxic effect of a new 1,3,4-thiadiazolium mesoionic compound (MI-D) on cell lines of human melanoma. Br J Cancer 2004; 91:297-304. [PMID: 15199390 PMCID: PMC2409799 DOI: 10.1038/sj.bjc.6601946] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The structural characteristics of mesoionic compounds, which contain distinct regions of positive and negative charges associated with a poly-heteroatomic system, enable them to cross cellular membranes and interact strongly with biomolecules. Potential biological applications have been described for mesoionic compounds. 1,3,4-Thiadiazolium mesoionic compound (MI-D), a new mesoionic compound, has been demonstrated to be extremely cytotoxic to B16-F10 murine melanoma cells when compared to fotemustine and dacarbazine, drugs of reference in melanoma treatment protocols, describing inhibition of tumours grown in vitro and in vivo. We now evaluate the effects of mesoionic compound MI-D on different human melanoma cell lines. The drug decreased the viability and proliferation of MEL-85, SK-MEL, A2058 and MEWO cell lines in vitro, showing a considerable cytotoxic activity on these human cells. Adhesion of MEL-85 cells was evaluated in the presence of the drug using different extracellular matrix (ECM) constituents. MI-D decreased MEL-85 adhesion to laminin, fibronectin and matrigel. The morphology and actin cytoskeleton organisation of MEL-85 cells were also modified on MI-D treatment. These results on human melanoma cell lines indicate that MI-D is a very encouraging drug against melanoma, a tumour that is extremely resistant to chemotherapy.
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Affiliation(s)
- A Senff-Ribeiro
- Department of Biochemistry and Molecular Biology, Federal University of Paraná, Curitiba, PR, Brazil
| | - A Echevarria
- Department of Chemistry, Rural Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - E F Silva
- Department of Chemistry, Rural Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - C R C Franco
- Department of Cellular Biology, Federal University of Paraná, Curitiba, PR, Brazil
| | - S S Veiga
- Department of Cellular Biology, Federal University of Paraná, Curitiba, PR, Brazil
| | - M B M Oliveira
- Department of Biochemistry and Molecular Biology, Federal University of Paraná, Curitiba, PR, Brazil
- Department of Biochemistry and Molecular Biology, Federal University of Paraná, Centro Politécnico, Jardim das Américas, Curitiba, Paraná, CEP 81.531-990, CP 19046, Brazil. E-mail:
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Freitas MAR, Vianna EN, Martins AS, Silva EF, Pesquero JL, Gomes MA. A single step duplex PCR to distinguish Entamoeba histolytica from Entamoeba dispar. Parasitology 2004; 128:625-8. [PMID: 15206464 DOI: 10.1017/s0031182004005086] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this study, a single-step duplex polymerase chain reaction procedure was developed for rapid, specific and sensitive identification of Entamoeba histolytica and for its diagnostic differentiation from E. dispar. Specific oligonucleotide primers were combined for the amplification of a cysteine proteinase 5 gene target sequence of 242 bp, present only in E. histolytica. Additionally, another oligonucleotide primer pair for both the E. histolytica and E. dispar actin gene target of 300 bp was designed to amplify only from amoebae DNA. The PCR developed was specific and efficiently identified and differentiated these parasites from each other in either cultured parasites or from stool material.
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Affiliation(s)
- M A R Freitas
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, CEP: 31270-901 Belo Horizonte, MG, Brasil
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36
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Furst C, Gomes MA, Tafuri WL, Silva EF. Biological aspects of a Brazilian strain of Entamoeba dispar. Pathologica 2002; 94:22-7. [PMID: 11912875] [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: 02/24/2023] Open
Abstract
A strain of Entamoeba dispar was characterized by clinical diagnosis, serological and electrophoretical isoenzyme analysis and by the polymorphism of a 482 bp genomic fragment analysis. The pathogenesis and virulence of this strain was investigated considering the experimental infection in hamster livers in association with the original intestinal microbiota. Liver lesions were observed in hamsters experimentally infected with trophozoites from xenic cultures, but not from the monoxenic cultures. Moreover, clones obtained from re-isolated strain Wil1R1 showed a distinct biological behavior. In fact, animals inoculated with Wil1R1ClB3 showed an intense acute inflammatory reaction with destructive focal hepatic lesions. These lesions were characterized as amebic abscesses. The association between bacteria and ameba has been fairly well studied because it affects the pathogenicity of the amebas and has important therapeutic implications. In this study, we demonstrated that E. dispar in association with the original microbiota is able to produce lesions in hamster liver in spite of its having been considered to be non-pathogenic in the hamster model. Based on these results we suggest that diagnosis of amebiasis needs to be made with more care and that clinical and therapeutical procedures need to be revised.
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Affiliation(s)
- C Furst
- Amebiasis Laboratory, Department of Parasitology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901-Belo Horizonte, Brazil
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Capella LS, Gefé M, Silva EF, Morales MM, Affonso-Mitidieri O, Lopes AG, Rumjanek VM, Capella MA. Reduced glutathione protect cells from ouabain toxicity. Biochim Biophys Acta 2001; 1526:293-300. [PMID: 11410339 DOI: 10.1016/s0304-4165(01)00144-1] [Citation(s) in RCA: 14] [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] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
It is widely accepted that a prolonged ouabain blockade of the Na(+),K(+)-ATPase makes cells detach from each other and from the substrate, leading to their death and that cellular resistance to ouabain is due to the presence of isoforms of Na(+),K(+)-ATPase with low affinity to this glycoside. In the present work the effect of reduced glutathione in the response of two types of renal cells to ouabain: MDCK, a ouabain-sensitive cell line and Ma104, a ouabain-resistant one, was studied. Glutathione protected MDCK cells from ouabain toxicity and inhibition of glutathione synthesis by L-buthionine-S,R-sulfoximine sensitized Ma104 cells to ouabain. As glutathione is involved with multidrug resistance (MDR) in cells expressing the multidrug resistance-related protein MRP1 and as Ma104 cells have a MDR phenotype, it was investigated whether Ma104 cells express this protein. The expression of the MRP1-mRNA in Ma104 cells was detected by reverse transcriptase-polymerase chain reaction and ribonuclease protection assay, and the protein was detected by Western blotting and immunofluorescence. Treatment of Ma104 cells with ouabain increased MRP1-mRNA expression and altered the localization of MRP1 in these cells. Our results suggest that some cells may have mechanisms to protect themselves from ouabain toxicity and that MRP1 may have a role in controlling the toxic effects of ouabain.
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Affiliation(s)
- L S Capella
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, Brazil.
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Abstract
Differences were detected in the gene expression of strains of E. histolytica using RNA (RAP-PCR) and DNA fingerprinting (RAPD). Analysis of the electrophoretic profiles of the gels revealed some polymorphic markers that could be used in the individual characterization of the strains. The 260 bands generated by using five different primers for RAP-PCR, as well as RAPD, were employed in the construction of dendograms. The dendogram obtained based on the RAPD products permitted the distinction of symptomatic and asymptomatic isolates, as well the correlation between the polymorphism exhibited and the virulence of the strains. The dendogram obtained for the RAP-PCR products did not show a correlation with the virulence of the strains but revealed a high degree of intraspecific transcriptional variability that could be related to other biological features, whether or not these are involved in the pathogenesis of amebiasis.
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Affiliation(s)
- P R Valle
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brasil
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Conceição M, Ramos KV, Silva EF, Neto FR, Peçanha EP, Rodrigues CR, Barreiro EJ, Fraga CA. Chiral gas chromatographic separation of 2-oxabicyclo[3.3.0]octane derivatives and their synthetic precursors. Anal Chem 2000; 72:3056-62. [PMID: 10939367 DOI: 10.1021/ac9912101] [Citation(s) in RCA: 4] [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: 11/28/2022]
Abstract
Chiral GC separation of (+/-)-2-allyl-2-carboethoxycyclopentanone (9) and the alcohols (+/-)-3-(hydroxymethyl)-5-carboethoxy-2-oxabicyclo[3.3.0]octane (7), (+/-)-2-allyl-2-carboethoxycyclopentanol (8), and their acetylated and trifluoroacetylated derivatives were investigated on three derivatized beta-cyclodextrins (CDs) diluted in SE-54 or 1701-OH: 2,3,6-tri-O-methyl-beta-CD (PMCD); 2,3-di-O-methyl-6-O-(tert-butyldimethylsilyl)-beta-CD (DIMETBCD); 2,3-di-O-acetyl-6-O-(tert-butyldimethylsilyl)-beta-CD (DIACTBCD). The understanding of these chiral separations is extremely relevant, since cyclopentanic and bicyclic cyclopentanic rings are common structural features of many important natural products and new pharmaceutical drugs. In general DIMETBCD diluted in SE-54 showed the best chiral resolution to alcohols 7 and 8 and only DIACTBCD showed enantioselectivity to 9. Hydrogen bonds prediction and dipole moments data were obtained by molecular modeling calculations for 7ab and 8ab and Ac and TFA derivatives. Comparison of these data with the chromatographic parameters for the related compounds were used to explain the differences of their elution orders and diastereo- and enantiomeric separations on the above chiral stationary phases (CSPs). The results suggest that the CSPs enantioselectivities are not affected by the carboethoxy-functionalized cyclopentanic and bicyclic cyclopentanic rings themselves but mainly by the functional group on the other stereogenic center.
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Affiliation(s)
- M Conceição
- LADETEC, Instituto de Química, Departamento de Química Orgânica, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Brazil.
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40
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Affiliation(s)
- C Furst
- Department of Parasitology, Institute of Biological Science, Federal University of Minas Gerais, Belo Horizonte, Brazil
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41
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Affiliation(s)
- A O Costa
- Laboratório de Amebíase, Departamento de Parasitologia, ICB-UFMG, Belo Horizonte, Brazil.
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Gomes MA, Melo MN, Macedo AM, Pena GP, Caliari MV, Silva EF. Characterization of Entamoeba histolytica and Entamoeba dispar by biological, biochemical, and molecular parameters. Arch Med Res 2000; 31:S249-50. [PMID: 11070303 DOI: 10.1016/s0188-4409(00)00213-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- M A Gomes
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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Barros FS, De Menezes LF, Pinheiro AA, Silva EF, Lopes AH, De Souza W, Meyer-Fernandes JR. Ectonucleotide diphosphohydrolase activities in Entamoeba histolytica. Arch Biochem Biophys 2000; 375:304-14. [PMID: 10700386 DOI: 10.1006/abbi.1999.1592] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [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: 01/23/2023]
Abstract
In this work, we describe the ability of living cells of Entamoeba histolytica to hydrolyze extracellular ATP. In these intact parasites, whose viability was determined by motility and by the eosin method, ATP hydrolysis was low in the absence of any divalent metal (78 nmol P(i)/h/10(5) cells). Interestingly, in the presence of 5 mM MgCl(2) an ecto-ATPase activity of 300 nmol P(i)/h/10(5) cells was observed. The addition of MgCl(2) to the extracellular medium increased the ecto-ATPase activity in a dose-dependent manner. At 5 mM ATP, half-maximal stimulation of ATP hydrolysis was obtained with 1.23 mM MgCl(2). Both activities were linear with cell density and with time for at least 1 h. The ecto-ATPase activity was also stimulated by MnCl(2) and CaCl(2) but not by SrCl(2), ZnCl(2), or FeCl(3). In fact, FeCl(3) inhibited both Mg(2+)-dependent and Mg(2+)-independent ecto-ATPase activities. The Mg(2+)-independent ATPase activity was unaffected by pH in the range between 6.4 and 8. 4, in which the cells were viable. However, the Mg(2+)-dependent ATPase activity was enhanced concomitantly with the increase in pH. In order to discard the possibility that the ATP hydrolysis observed was due to phosphatase or 5'-nucleotidase activities, several inhibitors for these enzymes were tested. Sodium orthovanadate, sodium fluoride, levamizole, and ammonium molybdate had no effect on the ATPase activities. In the absence of Mg(2+) (basal activity), the apparent K(m) for ATP(4-) was 0.053 +/- 0.008 mM, whereas at saturating MgCl(2) concentrations, the corresponding apparent K(m) for Mg-ATP(2-) for Mg(2+)-dependent ecto-ATPase activity (difference between total and basal ecto-ATPase activity) was 0.503 mM +/- 0.062. Both ecto-ATPase activities were highly specific for ATP and were also able to hydrolyze ADP less efficiently. To identify the observed hydrolytic activities as those of an ecto-ATPase, we used suramin, a competitive antagonist of P(2) purinoreceptors and an inhibitor of some ecto-ATPases, as well as the impermeant agent 4'-4'-diisothiocyanostylbenzene-2'-2'-disulfonic acid. These two reagents inhibited the Mg(2+)-independent and the Mg(2+)-dependent ATPase activities to different extents, and the inhibition by both agents was prevented by ATP. A comparison among the ecto-ATPase activities of three amoeba species showed that the noninvasive E. histolytica and the free-living E. moshkovskii were less efficient than the pathogenic E. histolytica in hydrolyzing ATP. As E. histolytica is known to have a galactose-specific lectin on its surface, which is related to the pathogenesis of amebiasis, galactose was tested for an effect on ecto-ATPase activities. It stimulated the Mg(2+)-dependent ecto-ATPase but not the Mg(2+)-independent ATPase activity.
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Affiliation(s)
- F S Barros
- Departamento de Bioquímica Médica, Instituto de Biofísica Carlos Chagas Filho, Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, RJ, Rio de Janeiro, CCS, Bloco H, Cidade Universitária, Ilha do Fundã
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Abstract
Genetic variability in Entamoeba histolytica was analyzed by random amplified polymorphic DNA (RAPD) using ten arbitrary primers. Due to intrinsic characteristics of the RAPD technique only axenic samples were analyzed. since the presence of any microorganism in the cultures interfered in the DNA profile by generating RAPDs not pertaining to E. histolytica. The RAPD profiles of E. histolytica samples isolated from patients with different clinical manifestations from different regions of the Americas shared about 70% of the bands produced. These profiles were compared to those obtained for E. moshkorskii, and E. invadens. The combined data for the ten primers were used in the phenetic analysis of all the isolates studied by using the Dice similarity coefficient as the genetic distance measure between the samples. Three distinct groups could be separated by phenon line: one including E. moshkovskii samples, which shared > 90% of the RAPDs produced by the different primers; one consisting solely of E. invadens; and a third comprising samples of E. histolytica, which showed considerable intraspecific variability.
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Affiliation(s)
- M A Gomes
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade fedral de Minas Gerais, Belo Horizonte, Brazil.
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Lapchik MS, Andrioli E, Melo M, Junior P, Leiro LC, Silva EF. Hospital urinary infection epidemic by Candida famata: reduction of mortality after therapy with fluconazole and identification of the risk factors related to the infection. Crit Care 2000. [PMCID: PMC3333012 DOI: 10.1186/cc808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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46
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Gomes MA, Pesquero JB, Furst C, Valle PR, Pesquero JL, Silva EF. An improved method to distinguish Entamoeba histolytica and Entamoeba dispar. Parasitology 1999; 119 ( Pt 4):359-62. [PMID: 10581613 DOI: 10.1017/s0031182099004886] [Citation(s) in RCA: 17] [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] [Indexed: 11/07/2022]
Abstract
A 482 base pair gene fragment from samples of amoebae E. histolytica and E. dispar was amplified by PCR. The amplification products of fragments from the 2 species of amoebae presented differences in mobility in non-denaturing polyacrylamide gel, probably due to sequence-dependent conformational alterations in the DNA fragments. The method described here permits E. histolytica and E. dispar to be distinguished with greater sensitivity and rapidity.
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Affiliation(s)
- M A Gomes
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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Gomes MA, Melo MN, Pesquero JL, Silva EF. Characterization for virulence of an axenic strain of Entamoeba histolytica: evidence for overexpression of two proteins. Arch Med Res 1998; 28:489-92. [PMID: 9428571] [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: 02/05/2023]
Abstract
The pattern of protein from membrane and crude homogenate of Entamoeba histolytica strain 462 axenically cultivated (462ac) and submitted to hamster liver passage (462hp) was obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The substrains 462ac and 462hp were compared by zymodeme analysis, erythrophagocytosis, cytopathic effect upon mammalian cells and the capability to induce abscess in hamster liver. The results showed no differences for erythrophagocytosis, cytopathic effect or zymodene for substrains 462ac and 462hp. A type II pathogenic zymodene was observed. Substrain 462ac did not induce liver abscess, but 462hp induced abscesses in 70% of the inoculated animals. The pattern of proteins from plasma membrane and crude homogenate were different. One protein of approximately 45kDa and another of 23 kDa showed at no detectable levels in the membrane of 462ac. A third component of approximately 90 kDa showed more intensively expressed in the 462ac.
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Affiliation(s)
- M A Gomes
- Department of Parasitology, Institute of Biological Services, Federal University of Minas Gerais, Belo Horizonte, Brazil
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48
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Gomes MA, Silva EF, Macedo AM, Vago AR, Melo MN. LSSP-PCR for characterization of strains of Entamoeba histolytica isolated in Brazil. Parasitology 1997; 114 ( Pt 6):517-20. [PMID: 9172422] [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: 02/04/2023]
Abstract
Strains of Entamoeba histolytica isolated in Brazil were characterized using the Low-Stringency Single Specific Primer PCR (LSSP-PCR), that detects single or multiple mutations in gene size DNA fragments. Using this technique, a 482-bp genomic DNA fragment from a structural gene in 8 strains and 2 clones of E. histolytica, isolated from symptomatic and asymptomatic patients in Brazil, including pathogenic and non-pathogenic zymodemes were studied. The results obtained indicate that LSSP-PCR is a valuable method for differentiating strains of E. histolytica. Moreover, the results are consistent with the concept that pathogenic and non-pathogenic strains of E. histolytica may represent distinct species or subspecies and are in accord with phenotypically characteristic isoenzyme patterns.
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Affiliation(s)
- M A Gomes
- Departamento de Parasitologia, Universidade Federal de Minas Gerais, Brasil
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Abstract
Differences in virulence of strains of Entamoeba histolytica have long been detected by various experimental assays, both in vivo and in vitro. Discrepancies in the strains characterization have been arisen when different biological assays are compared. In order to evaluate different parameters of virulence in the strains characterization, five strains of E. histolytica, kept under axenic culture, were characterized in respect to their, capability to induce hamster liver abscess, erythrophagocytosis rate and cytopathic effect upon VERO cells. It was found significant correlation between in vitro biological assays, but not between in vivo and in vitro assays. Good correlation was found between cytopathic effect and the mean number of uptaken erythrocytes, but not with percentage of phagocytic amoebae, showing that great variability can be observed in the same assay, according to the variable chosen. It was not possible to correlate isoenzyme and restriction fragment pattern with virulence indexes since all studied strains presented pathogenic patterns. The discordant results observed in different virulence assays suggests that virulence itself may not the directly assessed. What is in fact assessed are different biological characteristics or functions of the parasite more than virulence itself. These characteristics or functions may be related or not with pathogenic mechanisms occurring in the development of invasive amoebic disease.
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Affiliation(s)
- M A Gomes
- Dep. Parasitologia, ICB/UFMG, Belo Horizonte, MG, Brasil
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Silva EF, Gómes MA, Barral de Martínez AM. Entamoeba histolytica: axenization and characterization of isolated samples from symptomatic and asymptomatic patients from different regions of Brazil. Arch Med Res 1997; 28 Spec No:288-9. [PMID: 9033104] [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)
- E F Silva
- Departamento Parasitologia, Universidade Federal de Minas Gerais, Brazil
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