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1.
Extremophiles ; 27(3): 31, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37848738

RESUMO

There are few biophysical studies or structural characterizations of the type IV pilin system of extremophile bacteria, such as the acidophilic Acidithiobacillus thiooxidans. We set out to analyze their pili-comprising proteins, pilins, because these extracellular proteins are in constant interaction with protons of the acidic medium in which At. thiooxidans grows. We used the web server Operon Mapper to analyze and identify the cluster codified by the minor pilin of At. thiooxidans. In addition, we carried an in-silico characterization of such pilins using the VL-XT algorithm of PONDR® server. Our results showed that structural disorder prevails more in pilins of At. thiooxidans than in non-acidophilic bacteria. Further computational characterization showed that the pilins of At. thiooxidans are significantly enriched in hydroxy (serine and threonine) and amide (glutamine and asparagine) residues, and significantly reduced in charged residues (aspartic acid, glutamic acid, arginine and lysine). Similar results were obtained when comparing pilins from other Acidithiobacillus and other acidophilic bacteria from another genus versus neutrophilic bacteria, suggesting that these properties are intrinsic to pilins from acidic environments, most likely by maintaining solubility and stability in harsh conditions. These results give guidelines for the application of extracellular proteins of acidophiles in protein engineering.


Assuntos
Acidithiobacillus , Proteínas de Fímbrias , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/química , Proteínas de Fímbrias/metabolismo , Acidithiobacillus thiooxidans/genética , Acidithiobacillus thiooxidans/metabolismo , Aminoácidos/metabolismo , Acidithiobacillus/genética , Acidithiobacillus/metabolismo , Ácidos
2.
Luminescence ; 36(3): 788-794, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33386703

RESUMO

Diatom frustules have species-specific patterns of pores, striae, pores, and nanopores, periodically arranged on its silica surface, as sets of cavities that modify the vacuum electromagnetic density of states. Therefore, frustules may be considered photonic crystals; the interaction with light-emitting sources inside the pores may potentially result in enhancement or inhibition of their spontaneous radiative emission rate and frequencies. In this work, we studied the photoluminescence of cadmium sulfide nanoparticles (CdS-NP) deposited inside frustule cavities that conveyed evidence of cavity-NP interaction. We synthesized CdS-NP, a semiconductor compound achieving quantum dots small enough to impose confinement effects to the electronic states. CdS-NP and their clusters were physiosorbed onto the surface, striae, and predominantly inside the pores of the cleansed frustules of Amphora sp. A broad peak with a maximum intensity at 437 nm (2.84 eV) was recorded after excitation with a 375 nm light source, showing a large blue shift and signal amplification of the CdS-NP photoluminescence when these were embedded inside the pores of the silica frustule. Using the Brus equation, we estimated a NP size of 4.1 ± 0.2 nm for the CdS-NP snuggly packed inside the smaller pores of the frustule, of 10 ± 0.7 nm in average diameter, The emission Purcell enhancement factor for an emitting atom in a cavity was calculated. The obtained Q factor (c. 5) was smaller than typical Q factors for designed semiconductor cavities of similar dimensions, an expected situation if it is assumed that the pores are open-ended cavities.


Assuntos
Diatomáceas , Nanopartículas , Nanoestruturas , Óptica e Fotônica , Dióxido de Silício
3.
J Appl Microbiol ; 124(1): 126-135, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29112318

RESUMO

AIMS: The objective of this study was to show whether the edible part of broccoli has antibacterial and antifungal activity against micro-organism of importance in human health and vegetable spoilage, and to test if this effect was partially due to antimicrobial peptides (AMPs). METHODS AND RESULTS: Crude extracts were obtained from florets and stems of broccoli cultivar Avenger and the inhibitory effect was demonstrated against pathogenic bacteria (Bacillus cereus, Staphylococcus xylosus, Staphylococcus aureus, Shigella flexneri, Shigella sonnei, Proteus vulgaris), phytopathogenic fungi (Colletotrichum gloeosporioides, Asperigillus niger) and yeasts (Candida albicans and Rhodotorula sp.). It was shown that samples treated with proteolytic enzymes had a reduction of approximately 60% in antibacterial activity against Staph. xylosus, suggesting that proteinaceous compounds might play a role in the inhibitory effect. Antimicrobial components in crude extracts were thermoresistant and the highest activity was observed under acidic conditions. It was shown that antifungal activity of broccoli's crude extracts might not be attributed to chitinases. CONCLUSIONS: Organic broccoli cultivar Avenger has antimicrobial activity against pathogenic bacteria, yeast and phytophatogenic fungi. Data suggest that this effect is partially due to AMPs. SIGNIFICANCE AND IMPACT OF THE STUDY: Broccoli's crude extracts have activity not only against pathogenic bacteria but also against phytophatogenic fungi of importance in agriculture. We suggest for first time that the inhibitory effect is probably due to AMPs.


Assuntos
Brassica/química , Doenças das Plantas/microbiologia , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Fenômenos Fisiológicos Bacterianos , Fungos/efeitos dos fármacos , Fungos/fisiologia , Humanos , Testes de Sensibilidade Microbiana , Leveduras/efeitos dos fármacos , Leveduras/fisiologia
4.
Biotechnol Lett ; 40(1): 63-73, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28940098

RESUMO

OBJECTIVES: To develop a bioelectrochemical system (BES) to couple the biooxidation of chalcopyrite (CuFeS2), bioelectrogenesis, and the cathodic Cu2+ reduction, bioanodes of acidophilic (pH < 2) and aerobic chemolithoautotrophic bacteria Acidithiobacillus thiooxidans (sulfur oxidizing) and Leptospirillum sp. (Fe2+ oxidizing) were used. RESULTS: CuFeS2 biooxidation increases the charge transfer from the media due to the bioleaching of Cu and Fe. The biofilm on a graphite bar endows a more electropositive (anodic) character to the bioelectrode. By adding the bioleachate generated by both bacteria into the anodic chamber, the acidic bioleachate provides the faradaic intensity. The maximum current density was 0.86 ± 19 mA cm-2 due to the low potential of the BES of 0.18 ± 0.02 V. Such low potential was sufficient for the cathodic deposit of Cu2+. CONCLUSIONS: This work demonstrates a proof of concept for energy savings for mining industries: bioanodes of A. thiooxidans and Leptospirillum sp. are electroactive during the biooxidation of CuFeS2.


Assuntos
Acidithiobacillus thiooxidans/metabolismo , Fontes de Energia Bioelétrica , Cobre/metabolismo , Acidithiobacillus thiooxidans/crescimento & desenvolvimento , Eletrodos/microbiologia , Oxirredução
8.
Insect Mol Biol ; 25(4): 500-8, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27135433

RESUMO

The sterile insect technique (SIT) involves the mass release of sterile males to suppress insect pest populations. SIT has been improved for larval pests by the development of strains for female-specific tetracycline-suppressible (Tet-off) embryonic lethal systems for male-only populations. Here we describe the extension of this approach to the Mexican fruit fly, Anastrepha ludens, using a Tet-off driver construct with the Tet-transactivator (tTA) under embryo-specific Anastrepha suspensa serendipity α (As-sry-α) promoter regulation. In the absence of tetracycline, tTA acts upon a Tet-response element linked to the pro-apoptotic cell death gene lethal effector, head involuation defective (hid), from A. ludens (Alhid(Ala2) ) that contains a sex-specific intron splicing cassette, resulting in female-specific expression of the lethal effector. Parental adults double-homozygous for the driver/effector vectors were expected to yield male-only progeny when reared on Tet-free diet, but a complete lack of oviposited eggs resulted for each of the three strains tested. Ovary dissection revealed nonvitellogenic oocytes in all strains that was reversible by feeding females tetracycline for 5 days after eclosion, resulting in male-only adults in one strain. Presumably the sry-α promoter exhibits prezygotic maternal expression as well as zygotic embryonic expression in A. ludens, resulting in a Tet-off sterility effect in addition to female-specific lethality.


Assuntos
Controle Biológico de Vetores , Tephritidae/efeitos dos fármacos , Tetraciclinas/farmacologia , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/crescimento & desenvolvimento , Animais Geneticamente Modificados/fisiologia , Antibacterianos/farmacologia , Feminino , Genes Letais , Larva/efeitos dos fármacos , Larva/genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Reprodução/efeitos dos fármacos , Tephritidae/genética , Tephritidae/crescimento & desenvolvimento , Tephritidae/fisiologia
9.
BMC Genet ; 15 Suppl 2: S4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25472528

RESUMO

BACKGROUND: Reliable marking systems are critical to the prospective field release of transgenic insect strains. This is to unambiguously distinguish released insects from wild insects in the field that are collected in field traps, and tissue-specific markers, such as those that are sperm-specific, have particular uses such as identifying wild females that have mated with released males. For tephritid fruit flies such as the Mexican fruit fly, Anastrepha ludens, polyubiquitin-regulated fluorescent protein body markers allow transgenic fly identification, and fluorescent protein genes regulated by the spermatocyte-specific ß2-tubulin promoter effectively mark sperm. For sterile male release programs, both marking systems can be made male-specific by linkage to the Y chromosome. RESULTS: An A. ludens wild type strain was genetically transformed with a piggyBac vector, pBXL{PUbnlsEGFP, Asß2tub-DsRed.T3}, having the polyubiquitin-regulated EGFP body marker, and the ß2-tubulin-regulated DsRed.T3 sperm-specific marker. Autosomal insertion lines effectively expressed both markers, but a single Y-linked insertion (YEGFP strain) expressed only PUbnlsEGFP. This insertion was remobilized by transposase helper injection, which resulted in three new autosomal insertion lines that expressed both markers. This indicated that the original Y-linked Asß2tub-DsRed.T3 marker was functional, but specifically suppressed on the Y chromosome. The PUbnlsEGFP marker remained effective however, and the YEGFP strain was used to create a sexing strain by translocating the wild type allele of the black pupae (bp+) gene onto the Y, which was then introduced into the bp- mutant strain. This allows the mechanical separation of mutant female black pupae from male brown pupae, that can be identified as adults by EGFP fluorescence. CONCLUSIONS: A Y-linked insertion of the pBXL{PUbnlsEGFP, Asß2tub-DsRed.T3} transformation vector in A. ludens resulted in male-specific expression of the EGFP fluorescent protein marker, and was integrated into a black pupae translocation sexing strain (T(YEGFP/bp+), allowing the identification of male adults when used in sterile male release programs for population control. A unique observation was that expression of the Asß2tub-DsRed.T3 sperm-specific marker, which was functional in autosomal insertions, was specifically suppressed in the Y-linked insertion. This may relate to the Y chromosomal regulation of male-specific germ-line genes in Drosophila.


Assuntos
Animais Geneticamente Modificados , Genes de Insetos , Genes Ligados ao Cromossomo Y , Tephritidae/genética , Transgenes , Animais , Cromossomos de Insetos , Feminino , Genes Reporter , Aptidão Genética , Masculino , Fenótipo , Translocação Genética
10.
Luminescence ; 29(8): 969-76, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24585632

RESUMO

The diatom silicified cell wall (frustule) contains pore arrays at the micro- to nanometer scale that display efficient luminescence within the visible spectrum. Morphometric analysis of the size and arrangement of pores was conducted to observe whether any correlation exists with the photoluminescence (PL) of two diatom species of different ages. UV-excited PL displays four clearly defined peaks within the blue-region spectrum, on top of the broad PL characteristic of synthetic porous silicon dioxide, recorded for reference and where discrete lines are absent. A set of shifted emission lines was observed when diatom cultures reached adulthood. These discrete line shifts correlate with structural changes observed in adult frustules: reduction in pore diameter; appearance of pores within pores, 10 nm in size; an increase in the gap distance between stria; and the deposition of several girdle bands with a concomitant increase in the diatom waist length, as well as the appearance of pores on such bands. Destruction of the pores results in the disappearance of all discrete emission lines. The PL shifts are correlated with a substantial increment of Si-OH groups adsorbed on the frustule surface, as revealed by Fourier transform infrared spectroscopy.


Assuntos
Diatomáceas/fisiologia , Diatomáceas/citologia , Diatomáceas/ultraestrutura , Medições Luminescentes , Nanoestruturas , Porosidade , Dióxido de Silício/química , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Raios Ultravioleta
11.
Acta Ortop Mex ; 38(2): 105-108, 2024.
Artigo em Espanhol | MEDLINE | ID: mdl-38782476

RESUMO

INTRODUCTION: anterior cruciate ligament injuries (ACL) continue increasing in frecuency in the general population and sportmen who practice soccer and american football where we can locate 53% of the total of cases, the annual incidence is 70 per 100,000 persons. The incidence of this injuries has being increasing in women probably of the increase of the participation in such sports. OBJECTIVE: to document the causes of anterior cruciate ligament (ACL) plasty failure, as well as the diagnosis, surgical technique, and postoperative care of a revision ACL plasty surgery. MATERIAL AND METHODS: a search for relevant information, original research articles, clinical trials, and reviews in indexed journals was performed. RESULTS: anterior cruciate ligament injuries continue to increase among the general population and athletes who play soccer and American soccer mainly, in this population group we found 53% of the total cases. The gold standard for treatment is arthroscopic reconstruction of the ligament. ACL reconstruction surgery has good results, with an estimated 75-90% success rate. Long-term failures of anterior cruciate ligament repair represent 5-25%. Among the factors associated with this failure are technical errors, traumatic antecedents, biological factors, among others. CONCLUSIONS: in ACL revision surgery good results can be achieved with respect to graft stability, return to play and functional stability of the knee, but the results are generally inferior to those of primary ACL reconstruction.


INTRODUCCIÓN: las lesiones del ligamento cruzado anterior (LCA) continúan en aumento entre la población general y deportistas que practican fútbol soccer y americano en donde se encuentra 53% del total de los casos; la incidencia anual es de 70 por cada 100,000 personas. La incidencia de estas lesiones ha ido en aumento en mujeres, probablemente por el incremento de la participación deportiva. OBJETIVO: documentar las causas de fracaso de plastía de ligamento cruzado anterior (LCA), así como el diagnóstico, técnica quirúrgica, cuidado postquirúrgico de una cirugía de revisión de plastía LCA. MATERIAL Y MÉTODOS: se ha realizado una búsqueda de información relevante, artículos de investigación originales, ensayos clínicos y revisiones en revistas indexadas. RESULTADOS: las lesiones del ligamento cruzado anterior continúan en aumento entre la población general y deportistas que practican futbol soccer y americano principalmente; en este grupo de la población encontramos 53% del total de los casos. El estándar de oro para su tratamiento es la reconstrucción del ligamento por vía artroscópica. La cirugía de reconstrucción de LCA presentan buenos resultados, se estima 75-90% de éxito. Los fracasos a largo plazo de la reparación de ligamento cruzado anterior representan de 5-25%. Dentro de los factores asociados a este fracaso encontramos errores técnicos, antecedentes traumáticos, factores biológicos, entre otros. CONCLUSIONES: en la cirugía de revisión de LCA se pueden lograr buenos resultados con respecto a la estabilidad del injerto, regreso al juego y estabilidad funcional de la rodilla, pero los resultados son generalmente inferiores a los de la reconstrucción primaria del LCA.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Reoperação , Humanos , Reconstrução do Ligamento Cruzado Anterior/métodos , Reoperação/estatística & dados numéricos , Lesões do Ligamento Cruzado Anterior/cirurgia , Feminino
12.
Biochem Biophys Rep ; 39: 101797, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39161578

RESUMO

Thirty years since the first report on the PilY1 protein in bacteria, only the C-terminal domain has been crystallized; there is no study in which the N-terminal domain, let alone the complete protein, has been crystallized. In our laboratory, we are interested in characterizing the Type IV Pili (T4P) of Acidithiobacillus thiooxidans. We performed an in silico characterization of PilY1 and other pilins of the T4P of this acidophilic bacterium. In silico characterization is crucial for understanding how proteins adapt and function under extreme conditions. By analyzing the primary and secondary structures of proteins through computational methods, researchers can gain valuable insights into protein stability, key structural features, and unique amino acid compositions that contribute to resilience in harsh environments. Here, it is presented a description of the particularities of At. thiooxidans PilY1 through predictor software and homology data. Our results suggest that PilY1 from At. thiooxidans may have the same role as has been described for other PilY1 associated with T4P in neutrophilic bacteria; also, its C-terminal interacts (interface interaction) with the minor pilins PilX, PilW and PilV. The N-terminal region comprises domains such as the vWA and the MIDAS, involved in signaling, ligand-binding, and protein-protein interaction. In fact, the vWA domain has intrinsically disordered regions that enable it to maintain its structure over a wide pH range, not only at extreme acidity to which At. thiooxidans is adapted. The results obtained helped us design the correct methodology for its heterologous expression. This allowed us partially experimentally characterize it by obtaining the N-terminal domain recombinantly and evaluating its acid stability through fluorescence spectroscopy. The data suggest that it remains stable across pH changes. This work thus provides guidance for the characterization of extracellular proteins from extremophilic organisms.

13.
J Microbiol Biotechnol ; 34(3): 527-537, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38346803

RESUMO

Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.


Assuntos
Acidithiobacillus thiooxidans , Proteínas de Fímbrias , Proteínas de Fímbrias/genética , Acidithiobacillus thiooxidans/metabolismo , Fímbrias Bacterianas , Sulfetos/metabolismo , Minerais/metabolismo
14.
Appl Microbiol Biotechnol ; 97(13): 6065-75, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23053079

RESUMO

Biofilms of Acidithiobacillus thiooxidans were grown on the surface of massive chalcopyrite electrodes (MCE) where different secondary sulfur phases were previously formed by potentiostatic oxidation of MCE at 0.780≤Ean≤0.965 V (electrooxidized MCE, eMCE). The formation of mainly S° and minor amounts of CuS and Sn²â» were detected on eMCEs. The eMCEs were incubated with A. thiooxidans cells for 1, 12, 24, 48, and 120 h in order to temporally monitor changes in eMCE's secondary phases, biofilm structure, and extracellular polymeric substance (EPS) composition (lipids, proteins, and polysaccharides) using microscopic, spectroscopic, electrochemical, and biochemical techniques. The results show significant cell attachments with stratified biofilm structure since the first hour of incubation and EPS composition changes, the most important being production after 48-120 h when the highest amount of lipids and proteins were registered. During 120 h, periodic oxidation/formation of S°/Sn²â» was recorded on biooxidized eMCEs, until a stable CuS composition was formed. In contrast, no evidence of CuS formation was observed on the eMCEs of the abiotic control, confirming that CuS formation results from microbial activity. The surface transformation of eMCE induces a structural transformation of the biofilm, evolving directly to a multilayered biofilm with more hydrophobic EPS and proteins after 120 h. Our results suggest that A. thiooxidans responded to the spatial and temporal distribution and chemical reactivity of the Sn²â»/S°/CuS phases throughout 120 h. These results suggested a strong correlation between surface speciation, hydrophobic domains in EPS, and biofilm organization during chalcopyrite biooxidation by A. thiooxidans.


Assuntos
Acidithiobacillus thiooxidans/metabolismo , Acidithiobacillus thiooxidans/fisiologia , Biofilmes/crescimento & desenvolvimento , Cobre/metabolismo , Eletrodos/microbiologia , Aderência Bacteriana , Oxirredução
15.
Appl Microbiol Biotechnol ; 97(6): 2711-24, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22584430

RESUMO

Surfaces of massive chalcopyrite (CuFeS2) electrodes were modified by applying variable oxidation potential pulses under growth media in order to induce the formation of different secondary phases (e.g., copper-rich polysulfides, S n(2-); elemental sulfur, S(0); and covellite, CuS). The evolution of reactivity (oxidation capacity) of the resulting chalcopyrite surfaces considers a transition from passive or inactive (containing CuS and S n(2-)) to active (containing increasing amounts of S(0)) phases. Modified surfaces were incubated with cells of sulfur-oxidizing bacteria (Acidithiobacillus thiooxidans) for 24 h in a specific culture medium (pH 2). Abiotic control experiments were also performed to compare chemical and biological oxidation. After incubation, the density of cells attached to chalcopyrite surfaces, the structure of the formed biofilm, and their exopolysaccharides and nucleic acids were analyzed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy coupled to dispersive X-ray analysis (SEM-EDS). Additionally, CuS and S n(2-)/S(0) speciation, as well as secondary phase evolution, was carried out on biooxidized and abiotic chalcopyrite surfaces using Raman spectroscopy and SEM-EDS. Our results indicate that oxidized chalcopyrite surfaces initially containing inactive S n(2-) and S n(2-)/CuS phases were less colonized by A. thiooxidans as compared with surfaces containing active phases (mainly S(0)). Furthermore, it was observed that cells were partially covered by CuS and S(0) phases during biooxidation, especially at highly oxidized chalcopyrite surfaces, suggesting the innocuous effect of CuS phases during A. thiooxidans performance. These results may contribute to understanding the effect of the concomitant formation of refractory secondary phases (as CuS and inactive S n(2-)) during the biooxidation of chalcopyrite by sulfur-oxidizing microorganisms in bioleaching systems.


Assuntos
Acidithiobacillus thiooxidans/fisiologia , Biofilmes/crescimento & desenvolvimento , Cobre/metabolismo , Eletrodos/microbiologia , Acidithiobacillus thiooxidans/crescimento & desenvolvimento , Acidithiobacillus thiooxidans/metabolismo , Microscopia Confocal , Microscopia Eletrônica de Varredura , Oxirredução , Espectrometria por Raios X , Análise Espectral Raman
16.
Plant Dis ; 97(9): 1257, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30722458

RESUMO

Vinca (Catharantus roseus (L.) G. Don) is a common ornamental landscape plant. From July to September 2012, blighted and wilted vinca plants were found in retail stores, commercial nurseries, and urban landscape areas of Culiacan, Sinaloa, in northwestern Mexico. In several commercial nurseries and a retail store, incidence of the unknown disease on vinca plants ranged from 20 to 50%, resulting in significant economic losses. Symptoms of the disease started with a foliar blight, and if warm and wet conditions were present, the disease progressed, causing plant wilting and death. Surface-sterilized (0.5% NaOCl 1 min) diseased plant tissue was plated on V8 agar medium, and after 72 h of incubation at 25°C, white colonies of coenocytic mycelium were developed from the plated tissues. Isolates produced cottony colonies on V8 agar medium, grew well between 7 and 30°C (optimum of 25°C), and produced spherical, intercalary, and terminal chlamydospores (17 to 30 µm) and non caducous, papillate, spherical to ovoid sporangia of 30 to 39 × 21 to 31 µm. Based on these morphological characteristics, Phytophthora isolates were identified as Phytophthora nicotianae Breda de Haan (1,3). The identity of two representative isolates OV4 and OV11 was confirmed by sequence analysis of the rDNA internal transcribed spacers (ITS; GenBank Accession Nos. KC248202 and KC248201), and of the ß-tubulin (ß-tub; KC248404 and KC248403) and translation elongation factor 1-α (EF1-α; KC248206 and KC248205) genes. Comparative sequence analysis against the NCBI nucleotide database showed a high degree of identity with reference sequences of P. nicotianae (ITS, 99%; ß-tub, 99%; EF1-α, 100%) (2). A pathogenicity test with a representative isolate of P. nicotianae was performed on 10-week-old healthy vinca seedlings (n = 10). An aliquot of 10 ml of a zoosporic suspension (104 zoospores/ml) was sprayed onto the seedlings' leaves. An equal number of non-inoculated control seedlings were sprayed with sterile distilled water. Seedlings were maintained in a moist chamber at 25°C with 80 to 90% relative humidity and watered as needed with sterile water. Inoculated plants showed initial symptoms of foliar blight after 4 days, whereas control plants remained healthy. Ten days after inoculation, inoculated plants showed severe wilting. P. nicotianae was reisolated only from inoculated plants, thus fulfilling Koch's postulates. To our knowledge, this is the first report of P. nicotianae attacking annual vinca in northwestern Mexico. References: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (2) L. P. Kroon et al. Fungal Genet Biol. 41:766, 2004. (3) F. N. Martin et al. Plant Dis. 96:1080, 2013.

17.
J Econ Entomol ; 106(2): 735-41, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23786061

RESUMO

A new genetic sexing strain of the Mexican fruit fly, Anastrepha ludens (Loew), was evaluated in tests of sexual behavior to determine its possible application using the sterile insect technique. Tests in field cages measuring time to sexual maturity, compatibility with wild flies, and competitiveness were compared between the genetic sexing strain, Tapachula-7, and the mass-reared standard bisexual strain. The results indicated that the onset of sexual maturity was similar for both laboratory strains. Males from the Tapachula-7 strain do not differ from the standard bisexual strain in compatibility and competitiveness with wild insects. The results indicate that the release of Tapachula-7 males in the field would be viable in programs that use the sterile insect technique for the control of the Mexican fruit fly.


Assuntos
Comportamento Sexual Animal , Tephritidae/fisiologia , Animais , Feminino , Masculino , Controle Biológico de Vetores/métodos , Maturidade Sexual , Tephritidae/genética
18.
Med Intensiva ; 37(8): 519-74, 2013 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-23773859

RESUMO

INTRODUCTION: Optimal management of sedation, analgesia and delirium offers comfort and security for the critical care patient, allows support measures to be applied more easily and enables an integral approach of medical care, at the same time that lowers the incidence of complications, wich translates in better patient outcomes. OBJECTIVE: To update the Guía de práctica clínica basada en la evidencia para el manejo de la sedoanalgesia en el paciente adulto críticamente enfermo published in Medicina Intensiva in 2007, and give recommendations for the management of sedation, analgesia, and delirium. METHODOLOGY: A group of 21 intensivists from 9 countries of the Federación Panamericana e Ibérica de Sociedades de Medicina Crítica y Terapia Intensiva, 3 of them also specialists in clinical epidemiology and methodology, gathered for the development of guidelines. Assessment of evidence quality and recommendations were made based on the Grading of Recommendations Assessment, Development and Evaluation system. Strength of recommendations was classified as 1=strong, or 2=weak, and quality of evidence as A=high, B=moderate, or C=low. Two authors searched the following databases: MEDLINE through PUBMED, The Cochrane Library and Literatura Latinoamericana y del Caribe en Ciencias de la Salud and retrieved pertinent information. Members assigned to the 11 sections of the guidelines, based on the literature review, formulated the recommendations, that were discussed in plenary sessions. Only those recommendations that achieved more than 80% of consensus were approved for the final document. The Colombian Association of Critical Medicine and Intensive Care (AMCI) supported the elaboration of this guidelines. RESULTS: Four hundred sixty-seven articles were included for review. An increase in number and quality of publications was observed. This allowed to generate 64 strong recommendations with high and moderate quality of evidence in contrast to the 28 recommendations of the previous edition. CONCLUSIONS: This Guidelines contains recommendations and suggestions based on the best evidence available for the management of sedation, analgesia and delirium of the critically ill patient, including a bundle of strategies that serves this purpose. We highlight the assessment of pain and agitation/sedation through validated scales, the use of opioids initially to apropiate analgesic control, associated with multimodal strategies in order to reduce opioide consumption; to promote the lowest level of sedation necessary avoiding over-sedation. Also, in case of the need of sedatives, choose the most appropiate for the patient needs, avoiding the use of benzodiazepines and identify risk factors for delirium, in order to prevent its occurrence, diagnose delirium and treat it with the most suitable pharmacological agent, whether it is haloperidol, atypical antipsychotics or dexmedetomidine, once again, avoiding the use of benzodiazepines and decreasing the use of opioids.


Assuntos
Analgesia , Sedação Consciente , Cuidados Críticos/normas , Estado Terminal/terapia , Sedação Profunda , Algoritmos , Procedimentos Cirúrgicos Cardíacos , Delírio/terapia , Humanos , Falência Hepática/terapia , Doenças do Sistema Nervoso/terapia , Cuidados Pós-Operatórios , Insuficiência Renal/terapia , Respiração Artificial , Síndrome de Abstinência a Substâncias/terapia , Desmame do Respirador
19.
PPAR Res ; 2023: 1743289, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36875280

RESUMO

Obesity and diabetes mellitus are considered the most important diseases of the XXI century. Recently, many epidemiological studies have linked exposure to pesticides to the development of obesity and type 2 diabetes mellitus. The role of pesticides and their possible influence on the development of these diseases was investigated by examining the relationship between these compounds and one of the major nuclear receptor families controlling lipid and carbohydrate metabolism: the peroxisome proliferator-activated receptors (PPARs), PPARα, PPARß/δ, and PPARγ; this was possible through in silico, in vitro, and in vivo assays. The present review aims to show the effect of pesticides on PPARs and their contribution to the changes in energy metabolism that enable the development of obesity and type 2 diabetes mellitus.

20.
Appl Microbiol Biotechnol ; 95(3): 799-809, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22113561

RESUMO

Massive pyrite (FeS2) electrodes were potentiostatically modified by means of variable oxidation pulse to induce formation of diverse surface sulfur species (S(n)²â», S°). The evolution of reactivity of the resulting surfaces considers transition from passive (e.g., Fe(1-x )S2) to active sulfur species (e.g., Fe(1-x )S(2-y ), S°). Selected modified pyrite surfaces were incubated with cells of sulfur-oxidizing Acidithiobacillus thiooxidans for 24 h in a specific culture medium (pH 2). Abiotic control experiments were also performed to compare chemical and biological oxidation. After incubation, the attached cells density and their exopolysaccharides were analyzed by confocal laser scanning microscopy (CLMS) and atomic force microscopy (AFM) on bio-oxidized surfaces; additionally, S(n)²â»/S° speciation was carried out on bio-oxidized and abiotic pyrite surfaces using Raman spectroscopy. Our results indicate an important correlation between the evolution of S(n)²â»/S° surface species ratio and biofilm formation. Hence, pyrite surfaces with mainly passive-sulfur species were less colonized by A. thiooxidans as compared to surfaces with active sulfur species. These results provide knowledge that may contribute to establishing interfacial conditions that enhance or delay metal sulfide (MS) dissolution, as a function of the biofilm formed by sulfur-oxidizing bacteria.


Assuntos
Acidithiobacillus thiooxidans/fisiologia , Biofilmes/crescimento & desenvolvimento , Ferro/metabolismo , Sulfetos/metabolismo , Acidithiobacillus thiooxidans/crescimento & desenvolvimento , Acidithiobacillus thiooxidans/metabolismo , Meios de Cultura/química , Concentração de Íons de Hidrogênio , Microscopia de Força Atômica , Microscopia Confocal , Análise Espectral Raman
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