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1.
Transbound Emerg Dis ; 67(2): 1035-1041, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31733175

RESUMO

As an emerging disease, the porcine epidemic diarrhoea virus has caused substantial economic losses to the pork industry in Mexico, leading to piglet mortality rates of up to 100%. For detection, sequencing and genetic characterization of the virus, 68 samples of one-week-old piglets from pork farms in 17 states of Mexico were analysed. In total, 53 samples were positive by real-time RT-PCR, confirming the presence of the virus in 15 states. Twenty-eight samples from 10 states were amplified by endpoint RT-PCR, and 20 sequences of the spike gene were obtained. A phylogenetic analysis based on the spike gene demonstrated that all Mexican strains are in Group II and are classified as non-Indel-S emerging variants. Three strains showed amino acid insertions: PEDv/MEX/GTO/LI-DMZC15/2015 and PEDv/MEX/QRO/LI-DMZC45/2016 showed one amino acid insertion (424 Y425 and 447 D448 , respectively), and PEDv/MEX/QRO/LI-DMZC49/2019 showed one and two amino acid insertions (422 C423 and 537 SQ538 ), with the second insertion in the COE region. These results provide evidence of the prevalence of emerging, non-Indel-S strains of the virus are currently circulating in Mexico during 2016-2018, when three of which have amino acid insertions: PEDv/MEX/GTO/IN-DMZC15/2015 and PEDv/MEX/QRO/IN-DMZC45/2016 have one amino acid insertion each (424 Y425 and 447 D448 , respectively), and PEDv/MEX/QRO/IN-DMZC49/2019 has one (422 C423 ) and two amino acid insertions (537 SQ538 ), the latter being in the COE region, which could generate new antigenic variants.

2.
Virusdisease ; 30(3): 433-440, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31803811

RESUMO

Influenza A viruses cause respiratory disease in piglets, and maternal immunity plays an important role in protecting against Influenza virus infection. Nevertheless, in the presence of high levels of maternal antibodies against influenza, an adequate immune response is not developed. In this study, the effect of maternal antibodies against the swine influenza A/swine/New Jersey/11/1976/H1N1 virus (swH1N1) on clinical presentation, serological response, and lesions produced in colostrated and non-colostrated pigs was evaluated in pigs infected with the human influenza A/Mexico/La Gloria-3/2009/ H1N1 (pH1N1) and swH1N1 viruses. Our results indicated that between 2 and 4 days post-challenge, sneezing and mild nasal discharge were observed in all pigs. Body temperature in pigs from all treatment groups ranged between 39.2 and 39.3 °C. Pigs inoculated with the pH1N1 virus (421 g) exhibited a significantly lower daily weight gain than those inoculated with the swH1N1 virus (524 g). HI antibody titers against the pH1N1 virus were significantly different between colostrated (1.62) and non-colostrated (0.43) pigs. Significant differences in antibody titers were detected between pigs inoculated with the pH1N1 (1.28) or the swH1N1 virus (0.77) (P < 0.05). The highest percentage of pulmonary lesions was observed in non-colostrated/pH1N1 pigs (11.88%) at 6 days post-challenge. Cross reactivity was observed between the pH1N1 and swH1N1 viruses, as the maternal antibodies against the swH1N1 virus successfully neutralized the pH1N1 virus infection.

3.
Pharmaceutics ; 11(11)2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31766136

RESUMO

This work aimed to develop and evaluate pH-dependent systems based on nanospheres (NSphs) and nanocapsules (NCs) loaded with chlorhexidine (CHX) base as a novel formulation for the treatment of periodontal disease. Cellulose acetate phthalate (CAP) was employed as a pH-dependent polymeric material. The NSphs and NCs were prepared using the emulsion-diffusion technique and then characterized according to encapsulation efficiency (EE), size, zeta-potential, morphology, thermal properties, release profiles and a preliminary clinical panel test. The formulations showed 77% and 61% EE and 57% and 84% process efficiency (PE), respectively. Both systems were spherical with an average size of 250-300 nm. Differential scanning calorimetry (DSC) studies showed that the drug has the potential to be dispersed molecularly in the NSph matrix or dissolved in the oily center of the NCs. The CHX release test revealed that the release of NSphs-CHX follows Fickian diffusion involving diffusion-erosion processes. The NCs showed a slower release than the NSphs, following non-Fickian diffusion, which is indicative of anomalous transport. These nanosystems may, therefore, be employed as novel formulations for treating periodontal disease, due to (1) their coverage of a large surface area, (2) the controlled release of active substances at different pH, and (3) potential gingival tissue infiltration.

4.
Transbound Emerg Dis ; 66(4): 1436-1441, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30941894

RESUMO

Porcine deltacoronavirus has caused great economic losses in the swine industry worldwide. In this study, we carried out the first detection, sequencing and characterization of this virus in Mexico. We analysed 885 rectal samples by multiplex RT-PCR to determine coinfections. In addition, the Spike gene was amplified, sequenced and analysed phylogenetically. We found 85 positive samples for porcine deltacoronavirus, representing 9.6% of the total samples, and we determined that the most frequent coinfection was with porcine epidemic diarrhoea virus (54.1%). Four sequences of Mexican isolates were most closely related to those of the United States. The antigenic regions and the glycosylation site of the strains obtained coincide with those previously reported. This relationship is probably related to the commercial exchange of pigs between the US and Mexico and the geographical proximity of these two countries.


Assuntos
Infecções por Coronavirus/veterinária , Vírus da Diarreia Epidêmica Suína/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/análise , Doenças dos Suínos/epidemiologia , Animais , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , México/epidemiologia , Vírus da Diarreia Epidêmica Suína/genética , Prevalência , Suínos , Doenças dos Suínos/virologia
5.
Virusdisease ; 29(3): 385-389, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30159376

RESUMO

Porcine circovirus type 2 (PCV2), family Circoviridae, genus Circovirus infection in domestic pig has been associated with several pathological conditions being the most important of them the postweaning multisystemic wasting syndrome. Many studies have demonstrated the existence of three PCV2 genotypes (a, b, and c) and recently PCV3. Until now, these genotypes or subgenotypes have not been described in Mexico. We found genetic changes in ORF2 from nine strains of PCV2 obtained from samples of Jalisco, Veracruz, Estado de México, Hidalgo and Sonora states of Mexico. Our results shown the presence of two genotypes (PCV2a and PCV2b) as well as, the presence and differences between the reported subgenotypes. The subgenotype PCV2b (1A/1B, 1A) has a higher prevalence (87.5%) in comparison with PCV2a (2C) (12.5%).

6.
Int J Mol Sci ; 19(6)2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29882846

RESUMO

The vagina is a region of administration with a high contact surface to obtain local or systemic effects. This anatomical area represents special interest for government health systems for different sexually transmitted infections. However, the chemical changes of the vagina, as well as its abundant mucus in continuous exchange, act as a barrier and a challenge for the development of new drugs. For these purposes, the development of new pharmaceutical forms based on nanoparticles has been shown to offer various advantages, such as bioadhesion, easy penetration of the mucosa, and controlled release, in addition to decreasing the adverse effects of conventional pharmaceutical forms. In order to obtain nanoparticles for vaginal administration, the use of polymers of natural and synthetic origin including biodegradable and non-biodegradable systems have gained great interest both in nanospheres and in nanocapsules. The main aim of this review is to provide an overview of the development of nanotechnology for vaginal drug release, analyzing the different compositions of polymeric nanoparticles, and emphasizing new trends in each of the sections presented. At the end of this review, a section analyzes the properties of the vehicles employed for the administration of nanoparticles and discusses how to take advantage of the properties that they offer. This review aims to be a reference guide for new formulators interested in the vaginal route.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Polímeros/química , Administração Intravaginal , Feminino , Humanos
7.
Int J Pharm ; 545(1-2): 170-175, 2018 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-29729408

RESUMO

The aim of this study was to develop solid lipid nanoparticles (SLN) and introduce them into a direct compression process to evaluate their lubricant properties. The study consisted of preparing glyceryl behenate SLN (Compritol® 888 ATO) by hot dispersion, and magnesium stearate SLN by a novel nanoprecipitation/ion exchange method. The ejection force was measured for nanosystems and raw materials in a formulation typically used for direct compression. The smallest particle sizes obtained were 456 nm for Compritol® 888 ATO and 330 nm for magnesium stearate. Results show that the NPs used as lubricants in a direct compression model formulation provided efficient lubrication by maintaining the lubricating properties of the system, thereby decreasing the amount of lubricant used compared to the raw material. The lubricating effect showed an increase of 15-30% for magnesium stearate and Compritol® 888 ATO, compared to the raw material at concentrations above 2%.


Assuntos
Portadores de Fármacos , Ácidos Graxos/química , Lipídeos/química , Lubrificantes/química , Nanopartículas , Ácidos Esteáricos/química , Tecnologia Farmacêutica/métodos , Composição de Medicamentos , Troca Iônica , Nanotecnologia , Tamanho da Partícula
8.
Int J Mol Sci ; 19(3)2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29494548

RESUMO

Currently, nanotechnology represents an important tool and an efficient option for extending the shelf life of foods. Reducing particle size to nanometric scale gives materials distinct and improved properties compared to larger systems. For food applications, this technology allows the incorporation of hydrophilic and lipophilic substances with antimicrobial and antioxidant properties that can be released during storage periods to increase the shelf life of diverse products, including whole and fresh-cut fruits and vegetables, nuts, seeds, and cheese, among others. Edible coatings are usually prepared with natural polymers that are non-toxic, economical, and readily available. Nanosystems, in contrast, may also be prepared with biodegradable synthetic polymers, and liquid and solid lipids at room temperature. In this review, recent developments in the use of such nanosystems as nanoparticles, nanotubes, nanocomposites, and nanoemulsions, are discussed critically. The use of polymers as the support matrix for nanodispersions to form edible coatings for food preservation is also analyzed, but the central purpose of the article is to describe available information on nanosystems and their use in different food substrates to help formulators in their work.


Assuntos
Materiais Biocompatíveis , Materiais Revestidos Biocompatíveis , Conservação de Alimentos , Conservantes de Alimentos , Nanotecnologia , Materiais Biocompatíveis/química , Biopolímeros , Materiais Revestidos Biocompatíveis/química , Conservantes de Alimentos/química , Humanos , Nanopartículas/química
9.
Virus Genes ; 54(2): 215-224, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29243063

RESUMO

In Mexico, the first outbreaks suggestive of the circulation of the porcine epidemic diarrhea virus (PEDV) were identified at the beginning of July 2013. To identify the molecular characteristics of the PEDV Spike (S) gene in Mexico, 116 samples of the intestine and diarrhea of piglets with clinical signs of porcine epidemic diarrhea (PED) were obtained. Samples were collected from 14 farms located in six states of Mexico (Jalisco, Puebla, Sonora, Veracruz, Guanajuato, and Michoacán) from 2013 to 2016. To identify PEDV, we used real-time RT-PCR to discriminate between non-INDEL and INDEL strains. We chose samples according to state and year to characterize the S gene. After amplification of the S gene, the obtained products were sequenced and assembled. The complete amino acid sequences of the spike protein were used to perform an epitope analysis, which was used to determine null mutations in regions SS2, SS6, and 2C10 compared to the sequences of G2. A phylogenetic analysis determined the circulation of G2b and INDEL strains in Mexico. However, several mutations were recorded in the collagenase equivalent (COE) region that were related to the change in polarity and charge of the amino acid residues. The PEDV strain circulating in Jalisco in 2016 has an insertion of three amino acids (232LGL234) and one change in the antigenic site of the COE region, and strains from the years 2015 and 2016 changed the index of the surface probability, which could be related to the re-emergence of disease outbreaks.


Assuntos
Infecções por Coronavirus/veterinária , Variação Genética , Vírus da Diarreia Epidêmica Suína/classificação , Vírus da Diarreia Epidêmica Suína/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/genética , Doenças dos Suínos/virologia , Animais , Análise por Conglomerados , Colagenases/genética , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Epitopos/genética , Fezes/virologia , Intestinos/virologia , México/epidemiologia , Epidemiologia Molecular , Mutação , Filogenia , Vírus da Diarreia Epidêmica Suína/genética , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , Homologia de Sequência , Suínos , Doenças dos Suínos/epidemiologia
10.
Environ Pollut ; 227: 194-206, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28460237

RESUMO

Mediterranean Basin ecosystems, their unique biodiversity, and the key services they provide are currently at risk due to air pollution and climate change, yet only a limited number of isolated and geographically-restricted studies have addressed this topic, often with contrasting results. Particularities of air pollution in this region include high O3 levels due to high air temperatures and solar radiation, the stability of air masses, and dominance of dry over wet nitrogen deposition. Moreover, the unique abiotic and biotic factors (e.g., climate, vegetation type, relevance of Saharan dust inputs) modulating the response of Mediterranean ecosystems at various spatiotemporal scales make it difficult to understand, and thus predict, the consequences of human activities that cause air pollution in the Mediterranean Basin. Therefore, there is an urgent need to implement coordinated research and experimental platforms along with wider environmental monitoring networks in the region. In particular, a robust deposition monitoring network in conjunction with modelling estimates is crucial, possibly including a set of common biomonitors (ideally cryptogams, an important component of the Mediterranean vegetation), to help refine pollutant deposition maps. Additionally, increased attention must be paid to functional diversity measures in future air pollution and climate change studies to establish the necessary link between biodiversity and the provision of ecosystem services in Mediterranean ecosystems. Through a coordinated effort, the Mediterranean scientific community can fill the above-mentioned gaps and reach a greater understanding of the mechanisms underlying the combined effects of air pollution and climate change in the Mediterranean Basin.


Assuntos
Poluentes Atmosféricos/análise , Atmosfera/química , Mudança Climática , Ecossistema , Monitoramento Ambiental , Poluição do Ar/estatística & dados numéricos , Biodiversidade , Clima , Humanos , Nitrogênio/análise , Pesquisa
11.
Environ Sci Pollut Res Int ; 24(34): 26259-26268, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28455565

RESUMO

Ozone (O3) critical levels have been established under the Long-Range Transboundary Air Pollution Convention to assess the risk of O3 effects in European vegetation. A recent review study has led to the development of O3 critical levels for annual Mediterranean pasture species using plants growing in well-watered pots at a coastal site and under low levels of competition. However, uncertainties remain in the extrapolation of the O3 sensitivity of these species under natural conditions. The response of two O3-sensitive annual Mediterranean pasture Trifolium species at the coastal site was compared with the response of the same species growing at a continental site, in natural soil and subject to water-stress and inter-specific competition, representing more closely their natural habitat. The slopes of exposure- and dose-response relationships derived for the two sites showed differences in the response to O3 between sites attributed to differences in environmental growing conditions, growing medium and the level of inter-specific competition, but the effect of the individual factors could not be assessed separately. Dose-based O3 indices partially explained differences due to environmental growing conditions between sites. The slopes showed that plants were more sensitive to O3 at the continental site, but homogeneity of slopes tests revealed that results from both experimental sites may be combined. Although more experimental data considering complex inter-specific competition situations and the effect of important interactive factors such as nitrogen would be needed, these results confirm the validity of applying the current flux-based O3 critical level under close to natural growing conditions. The AOT40-based O3 critical level derived at the coastal site was also considered a suitable risk indicator in close to natural growing conditions in the absence of soil moisture limitations on plant growth.


Assuntos
Poluentes Atmosféricos/toxicidade , Monitoramento Ambiental/métodos , Ozônio/toxicidade , Trifolium/efeitos dos fármacos , Poluentes Atmosféricos/análise , Ecossistema , Nitrogênio , Ozônio/análise
12.
Vaccine ; 32(50): 6805-11, 2014 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-25446832

RESUMO

The main goal of this work was to obtain an orally administered immunogen that would protect against infections by Actinobacillus pleuropneumoniae. The Apx I, II and III toxins were obtained from the supernatants of cultures of serotypes 1 and 3 of A. pleuropneumoniae. The capacity of monoolein gel to trap and protect the Apx toxins, and the effect of their incorporation on the stability of the cubic phase were evaluated. The gel was capable of trapping a 400-µg/ml concentration of the antigen with no effects on its structure. Approximately 60% of the protein molecules were released from the gel within 4h. Four experimental groups were formed, each one with four pigs. All challenges were conducted in a nebulization chamber. Group A: Control (-) not vaccinated and not challenged; Group B: Control (+) not vaccinated but challenged; Group C: vaccinated twice intramuscularly with ToxCom (a commercial toxoid) at an interval of 15 days and then challenged; and Group D: vaccinated orally twice a week for 4 weeks with ToxOral (an oral toxoid) and challenged on day 28 of the experiment with a same dose of 2.0 × 10(4) UFC of A. pleuropneumoniae serotypes 1 and 3. The lesions found in group B covered 27.7-43.1% of the lungs; the pigs in group C had lesions over 12.3-28%; and those in group D over 15.4-32.3%. No lesions were found in the Group A pigs. A. pleuropneumoniae induced macroscopic lesions characteristic of infection by and lesions microscopic detected by histopathology. The etiologic agent was recovered from the infected lungs, tonsils and spleen. The serotypes identified were 1 and 3. An indirect ELISA test identified the antibodies against the Apx toxins in the serum of the animals immunized orally.


Assuntos
Infecções por Actinobacillus/veterinária , Actinobacillus pleuropneumoniae/imunologia , Toxinas Bacterianas/imunologia , Portadores de Fármacos/administração & dosagem , Glicerídeos/administração & dosagem , Pleuropneumonia/veterinária , Doenças dos Suínos/prevenção & controle , Infecções por Actinobacillus/prevenção & controle , Administração Oral , Animais , Toxinas Bacterianas/administração & dosagem , Toxinas Bacterianas/isolamento & purificação , Histocitoquímica , Imunização/métodos , Pulmão/microbiologia , Pulmão/patologia , Tonsila Palatina/microbiologia , Pleuropneumonia/prevenção & controle , Baço/microbiologia , Suínos
13.
Ultrasonics ; 51(7): 839-45, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21570702

RESUMO

The aim of this study was to prepare air-filled nanocapsules intended ultrasound contrast agents (UCAs) with a biodegradable polymeric shell composed of poly(d,l-lactide-co-glycolide) (PLGA). Because of their size, current commercial UCAs are not capable of penetrating the irregular vasculature that feeds growing tumors. The new generation of UCAs should be designed on the nanoscale to enhance tumor detection, in addition, the polymeric shell in contrast with monomolecular stabilized UCAs improves the mechanical properties against ultrasound pressure and lack of stability. The preparation method of air-filled nanocapsules was based on a modification of the double-emulsion solvent evaporation technique. Air-filled nanocapsules with a mean diameter of 370±96nm were obtained. Electronic microscopies revealed spherical-shaped particles with smooth surfaces and a capsular morphology, with a shell thickness of ∼50nm. Air-filled nanocapsules showed echogenic power in vitro, providing an enhancement of up to 15dB at a concentration of 0.045mg/mL at a frequency of 10MHz. Loss of signal for air-filled nanocapsules was 2dB after 30min, suggesting high stability. The prepared contrast agent in this work has the potential to be used in ultrasound imaging.


Assuntos
Meios de Contraste/síntese química , Ácido Láctico/química , Nanocápsulas/química , Ácido Poliglicólico/química , Ultrassonografia , Ar , Bicarbonatos/química , Materiais Biocompatíveis/química , Emulsões/química , Técnicas In Vitro , Microscopia Eletrônica , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Solventes/química
14.
Environ Pollut ; 159(8-9): 2138-47, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21269745

RESUMO

Tropospheric ozone (O(3)) is considered one of the most important air pollutants affecting human health. The role of peri-urban vegetation in modifying O(3) concentrations has been analyzed in the Madrid region (Spain) using the V200603par-rc1 version of the CHIMERE air quality model. The 3.7 version of the MM5 meteorological model was used to provide meteorological input data to the CHIMERE. The emissions were derived from the EMEP database for 2003. Land use data and the stomatal conductance model included in CHIMERE were modified according to the latest information available for the study area. Two cases were considered for the period April-September 2003: (1) actual land use and (2) a fictitious scenario where El Pardo peri-urban forest was converted to bare-soil. The results show that El Pardo forest constitutes a sink of O(3) since removing this green area increased O(3) levels over the modified area and over down-wind surrounding areas.


Assuntos
Poluição do Ar/estatística & dados numéricos , Monitoramento Ambiental/métodos , Modelos Químicos , Árvores/fisiologia , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/metabolismo , Cidades , Ozônio/análise , Ozônio/metabolismo , Espanha , Árvores/classificação , Árvores/metabolismo
15.
Environ Pollut ; 155(3): 473-80, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18342418

RESUMO

A sensitivity analysis of a proposed parameterization of the stomatal conductance (g(s)) module of the European ozone deposition model (DO(3)SE) for Quercus ilex was performed. The performance of the model was tested against measured g(s) in the field at three sites in Spain. The best fit of the model was found for those sites, or during those periods, facing no or mild stress conditions, but a worse performance was found under severe drought or temperature stress, mostly occurring at continental sites. The best performance was obtained when both f(phen) and f(SWP) were included. A local parameterization accounting for the lower temperatures recorded in winter and the higher water shortage at the continental sites resulted in a better performance of the model. The overall results indicate that two different parameterizations of the model are needed, one for marine-influenced sites and another one for continental sites.


Assuntos
Poluentes Atmosféricos/metabolismo , Oxidantes Fotoquímicos/metabolismo , Ozônio/metabolismo , Estômatos de Plantas/fisiologia , Quercus/metabolismo , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Geografia , Modelos Biológicos , Oxidantes Fotoquímicos/análise , Ozônio/análise , Transpiração Vegetal , Estações do Ano , Espanha
16.
Rev Iberoam Micol ; 24(2): 136-41, 2007 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-17604433

RESUMO

The coexistence of the aflatoxin (AFB) and fumonisin (FB) has been widely documented in many parts of the world. However, few studies describing the synergy effect of both mycotoxins in vivo and/or in vitro are available. The objective of this study consisted on evaluating the effect of AFB and FB on the morphology, the capacity of cellular proliferation, cytotoxicity and interleukin-8 (IL-8) synthesis in a porcine intestinal epithelial cell line (IPEC-1). Concerning to the cellular morphology it was only affected in the concentrations higher of AFB (50 microM) and FB (500 microM). However, the cellular proliferation, the cellular damage and synthesis of IL-8 they were affected when present in combination the AFB/FB (1.3/3.7; 2/3.7 and 5/10 microM respectively) with that showed by the individual effect of similar concentrations of these mycotoxins (p < 0.05). Our data indicate that the combination of AFB/FB in low concentrations showed a synergy effect, altering the cellular morphophysiology, which can imply in vivo the entrance of other toxins or biological agents for alteration of the intestinal barrier impacting negatively in the human or animal health.


Assuntos
Aflatoxina B1/toxicidade , Citotoxinas/toxicidade , Células Epiteliais/efeitos dos fármacos , Fumonisinas/toxicidade , Aflatoxina B1/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Linhagem Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular , Citotoxinas/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Células Epiteliais/ultraestrutura , Fumonisinas/farmacologia , Interleucina-8/biossíntese , Mucosa Intestinal/citologia , Intestino Delgado/citologia , L-Lactato Desidrogenase/análise , Sus scrofa
17.
ScientificWorldJournal ; 7 Suppl 1: 119-27, 2007 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-17450288

RESUMO

An ozone (O3) deposition model (DO3SE) is currently used in Europe to define the areas where O3 concentrations lead to absorbed O3 doses that exceed the flux-based critical levels above which phytotoxic effects would be likely recorded. This mapping exercise relies mostly on the accurate estimation of O3 flux through plant stomata. However, the present parameterization of the modulation of stomatal conductance (g(s)) behavior by different environmental variables needs further adjustment if O3 phytotoxicity is to be assessed accurately at regional or continental scales. A new parameterization of the model is proposed for Holm oak (Quercus ilex), a tree species that has been selected as a surrogate for all Mediterranean evergreen broadleaf species. This parameterization was based on a literature review, and was calibrated and validated using experimentally measured data of g(s) and several atmospheric and soil parameters recorded at three sites of the Iberian Peninsula experiencing long summer drought, and very cold and dry winter air (El Pardo and Miraflores) or milder conditions (Tietar). A fairly good agreement was found between modeled and measured data (R2 = 0.64) at Tietar. However, a reasonable performance (R2 = 0.47-0.62) of the model was only achieved at the most continental sites when g(s) and soil moisture deficit relationships were considered. The influence of root depth on g(s) estimation is discussed and recommendations are made to build up separate parameterizations for continental and marine-influenced Holm oak sites in the future.


Assuntos
Poluentes Atmosféricos/metabolismo , Modelos Biológicos , Ozônio/metabolismo , Quercus/metabolismo , Poluentes Atmosféricos/toxicidade , Atmosfera , Calibragem , Monitoramento Ambiental , Região do Mediterrâneo , Ozônio/toxicidade , Epiderme Vegetal/metabolismo , Folhas de Planta/metabolismo , Quercus/efeitos dos fármacos , Solo
18.
Environ Pollut ; 146(3): 617-23, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17029685

RESUMO

The data from a previous experiment carried out in open-top chambers to assess the effects of ozone (O3) exposure on growth and physiology of Aleppo pine (Pinus halepensis Mill.) were re-assessed to test the performance of the EMEP O3 stomatal conductance model used to estimate tree O3 uptake at a European scale. Aleppo pine seedlings were exposed during three consecutive years to three different O3 treatments: charcoal filtered air, non-filtered air and non-filtered air supplemented with 40 nl l(-1). The results of the model using the default parameterisation already published for Mediterranean conifers showed a poor performance when compared to measured data. Therefore, modifications of g(max), f(min), and new f(VPD), f(temp) and f(phen) functions were developed according to the observed data. This re-parameterisation resulted in a significant improvement of the performance of the model when compared to its original version.


Assuntos
Oxidantes Fotoquímicos/toxicidade , Ozônio/toxicidade , Pinus/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Modelos Biológicos , Oxidantes Fotoquímicos/farmacocinética , Ozônio/farmacocinética , Pinus/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Estações do Ano , Plântula/efeitos dos fármacos , Plântula/metabolismo
19.
Rev. iberoam. micol ; 24(2): 136-141, 2007. ilus
Artigo em Espanhol | IBECS | ID: ibc-76586

RESUMO

La coexistencia de la aflatoxina (AFB) y la fumonisina (FB) es ampliamenteconocida en muchas partes del mundo; sin embargo existen pocos estudiosque describan el efecto sinérgico de ambas micotoxinas in vivo o in vitro. Elobjetivo de este trabajo fue evaluar la citotoxicidad y el efecto de AFB y FBsobre la morfología, la capacidad proliferativa celular y la síntesis deinterleucina 8 (IL-8) en una línea celular de epitelio intestinal porcino (IPEC-1).Respecto a la morfología celular, ésta se vio afectada únicamente en lasconcentraciones más altas de AFB (50 μM) y FB (500 μM). Sin embargo laproliferación celular, el daño celular y la síntesis de IL-8 se vieron afectadascon la combinación AFB/FB (1,3/3,7; 2/3,7 y 5/10 μM, respectivamente), alcompararlas con el efecto individual de estas micotoxinas a las mismasconcentraciones (p < 0,05). Nuestros datos indican que la combinaciónAFB/FB en concentraciones bajas muestra un efecto sinérgico, alterando lamorfofisiología de las células utilizadas, lo que puede implicar, in vivo, laentrada de otras toxinas o agentes biológicos al estar alterada la barreraintestinal, impactando negativamente en la salud humana o animal(AU)


The coexistence of the aflatoxin (AFB) and fumonisin (FB) has been widelydocumented in many parts of the world. However, few studies describing thesynergy effect of both mycotoxins in vivo and/or in vitro are available. Theobjective of this study consisted on evaluating the effect of AFB and FB onthe morphology, the capacity of cellular proliferation, cytotoxicity andinterleukina-8 (IL-8) synthesis in a porcine intestinal epithelial cell line (IPEC-1).Concerning to the cellular morphology it was only affected in theconcentrations higher of AFB (50 μM) and FB (500 μM). However, the cellularproliferation, the cellular damage and synthesis of IL-8 they were affectedwhen present in combination the AFB/FB (1.3/3.7; 2/3.7 and 5/10 μMrespectively) with that showed by the individual effect of similar concentrationsof these mycotoxins (p < 0.05). Our data indicate that the combination ofAFB/FB in low concentrations showed a synergy effect, altering the cellularmorfophisiology, which can imply in vivo the entrance of other toxins orbiological agents for alteration of the intestinal barrier impacting negatively inthe human or animal health(AU)


Assuntos
Animais , Citotoxinas/isolamento & purificação , Aflatoxinas/isolamento & purificação , Fumonisinas/isolamento & purificação , Células Enteroendócrinas/microbiologia , Suínos/microbiologia , Sobrevivência Celular , Interleucina-8/síntese química , Citocinas/isolamento & purificação
20.
Environ Pollut ; 134(2): 291-300, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15589656

RESUMO

Four Mediterranean tree taxa, Quercus ilex subsp. ilex, Quercus ilex subsp. ballota, Olea europaea cv. vulgaris and Ceratonia siliqua, were exposed to different ozone (O(3)) concentrations in open top chambers (OTCs) during 2 years. Three treatments were applied: charcoal-filtered air (CF), non-filtered air (NF) and non-filtered air plus 40 ppb(v) of O(3) (NF +). The photochemical maximal efficiency, Fv/Fm, decreased in NF + plants during the second year of exposure, especially during the most stressful Mediterranean seasons (winter and summer). An increase of delta(13)C was found in three of the four studied species during the first year of exposure. This finding was only maintained in C. siliqua during the second year. Decreases in the chlorophyll content were detected during the first year of fumigations in all the species studied, but not during the second year. The NF + treatment induced changes in foliar anatomical characteristics, especially in leaf mass per area (LMA) and spongy parenchyma thickness, which increased in some species. A reduction in N content and an increase in delta(15)N were found in all species during the second year when exposed in the NF + OTCs, suggesting a change in their retranslocation pattern linked to an acceleration of leaf senescence, as also indicated by the above mentioned biochemical and anatomical foliar changes. The two Q. ilex subspecies were the most sensitive species since the changes in N concentration, delta(15)N, chlorophyll, leaf area, LMA and biomass occurred at ambient O(3) concentrations. However, C. siliqua was the most responsive species (29% biomass reduction) when exposed to the NF + treatment, followed by the two Q. ilex subspecies (14-20%) and O. europaea (no significant reduction). Ozone resistance of the latter species was linked to some plant traits such as chlorophyll concentrations, or spongy parenchyma thickness.


Assuntos
Magnoliopsida/efeitos dos fármacos , Oxidantes Fotoquímicos/toxicidade , Ozônio/toxicidade , Folhas de Planta/efeitos dos fármacos , Plântula/efeitos dos fármacos , Biomassa , Isótopos de Carbono/análise , Clorofila/análise , Clorofila/metabolismo , Monitoramento Ambiental/métodos , Fabaceae/anatomia & histologia , Fabaceae/efeitos dos fármacos , Fabaceae/fisiologia , Magnoliopsida/anatomia & histologia , Magnoliopsida/fisiologia , Nitrogênio/análise , Olea/anatomia & histologia , Olea/efeitos dos fármacos , Olea/fisiologia , Fotossíntese/fisiologia , Folhas de Planta/anatomia & histologia , Folhas de Planta/fisiologia , Quercus/anatomia & histologia , Quercus/efeitos dos fármacos , Quercus/fisiologia , Estações do Ano , Plântula/anatomia & histologia , Plântula/fisiologia
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