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1.
Ann Plast Surg ; 92(6): 621-624, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38717197

RESUMEN

ABSTRACT: The unique dual-lumen and baffle design of the IDEAL IMPLANT Structured Saline breast implant gives it specific advantages over both silicone gel-filled and the original saline-filled implants. This internal baffle structure also gives it an appearance on various radiologic imaging studies that may be misinterpreted as a rupture because of similarities to the well-known radiologic appearance of a ruptured silicone gel implant. Patients may present with various misinterpreted imaging studies, highlighting the need for plastic surgeons and radiologists to be familiar with the normal appearance of the intact IDEAL IMPLANT and be able to distinguish it from a ruptured IDEAL IMPLANT. The radiology findings must be correlated with the clinical findings, or an intact IDEAL IMPLANT misdiagnosed as ruptured, may cause unnecessary patient worry, and may prompt unnecessary surgery for removal or replacement.


Asunto(s)
Implantes de Mama , Remoción de Dispositivos , Errores Diagnósticos , Falla de Prótesis , Femenino , Humanos , Implantación de Mama/efectos adversos , Implantación de Mama/métodos , Implantes de Mama/efectos adversos , Diseño de Prótesis , Solución Salina , Geles de Silicona , Procedimientos Innecesarios
2.
Phys Chem Chem Phys ; 21(41): 23111-23118, 2019 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-31603442

RESUMEN

Lithium-ion diffusion mechanisms in the complex spinel Li2NiGe3O8 have been investigated using solid-state NMR, impedance, and muon spectroscopies. Partial occupancy of migratory interstitial 12d sites is shown to occur at lower temperatures than previously reported. Bulk activation energies for Li+ ion hopping range from 0.43 ± 0.03 eV for powdered samples to 0.53 ± 0.01 eV for samples sintered at 950 °C for 24 h, due to the loss of Li during sintering at elevated temperatures. A lithium diffusion coefficient of 3.89 × 10-12 cm2 s-1 was calculated from muon spectroscopy data for Li2NiGe3O8 at 300 K.

3.
Inorg Chem ; 56(1): 542-547, 2017 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-27977162

RESUMEN

Novel synthetic routes to prepare functional oxides at lower temperatures are an increasingly important area of research. Many of these synthetic routes, however, use water as the solvent and rely on dissolution of the precursors, precluding their use with, for example, titanates. Here we present a low-cost solvent system as a means to rapidly create phase-pure ferroelectric barium titanate using a choline chloride-malonic acid deep eutectic solvent. This solvent is compatible with alkoxide precursors and allows for the rapid synthesis of nanoscale barium titanate powders at 950 °C. The phase and morphology were determined, along with investigation of the synthetic pathway, with the reaction proceeding via BaCl2 and TiO2 intermediates. The powders were also used to create sintered ceramics, which exhibit a permittivity maximum corresponding to a tetragonal-cubic transition at 112 °C, as opposed to the more conventional temperature of ∼120 °C. The lower-than-expected value for the ferro- to para-electric phase transition is likely due to undetectable levels of contaminants.

4.
NASN Sch Nurse ; 39(5): 242-246, 2024 09.
Artículo en Inglés | MEDLINE | ID: mdl-39219369

RESUMEN

Asthma is common among the pediatric population. Exacerbations of this chronic condition can lead to emergency department visits and hospitalizations, resulting in time away from school. Children spend the majority of their day at school, where they may need access to quick relief medication to treat respiratory distress. Students' personal asthma medication is not always available in school. School nurses in Illinois collected data and undertook a quality improvement project to increase the number of schools in North Suburban Cook County with undesignated asthma medication. A toolkit was created and shared, helping to remediate barriers associated with obtaining undesignated asthma medication. With access to undesignated asthma medication, school nurses ensure students with asthma receive prompt treatment and coordination of care.


Asunto(s)
Asma , Accesibilidad a los Servicios de Salud , Servicios de Enfermería Escolar , Humanos , Asma/tratamiento farmacológico , Asma/enfermería , Illinois , Niño , Antiasmáticos/uso terapéutico , Antiasmáticos/administración & dosificación , Mejoramiento de la Calidad
5.
Life Sci Alliance ; 7(4)2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38316462

RESUMEN

Bidirectional interactions between the immune system and the gut microbiota are key contributors to various physiological functions. Immune-associated diseases such as cancer and autoimmunity, and efficacy of immunomodulatory therapies, have been linked to microbiome variation. Although COVID-19 infection has been shown to cause microbial dysbiosis, it remains understudied whether the inflammatory response associated with vaccination also impacts the microbiota. Here, we investigate the temporal impact of COVID-19 vaccination on the gut microbiome in healthy and immuno-compromised individuals; the latter included patients with primary immunodeficiency and cancer patients on immunomodulating therapies. We find that the gut microbiome remained remarkably stable post-vaccination irrespective of diverse immune status, vaccine response, and microbial composition spanned by the cohort. The stability is evident at all evaluated levels including diversity, phylum, species, and functional capacity. Our results indicate the resilience of the gut microbiome to host immune changes triggered by COVID-19 vaccination and suggest minimal, if any, impact on microbiome-mediated processes. These findings encourage vaccine acceptance, particularly when contrasted with the significant microbiome shifts observed during COVID-19 infection.


Asunto(s)
COVID-19 , Microbioma Gastrointestinal , Neoplasias , Humanos , Vacunas contra la COVID-19 , COVID-19/prevención & control , Vacunación
6.
Nanoscale ; 15(28): 12087-12094, 2023 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-37417804

RESUMEN

Sodium ion batteries represent a sustainable alternative to Li-ion technologies. Challenges with material properties remain, however, particularly with regards the performance of anodes. We report a rapid, energy-efficient ionic liquid synthesis method for mixed phase Na2Ti3O7 and Na2Ti6O13 rods. This method is based on a novel phase-transfer route which produces pure functional materials via a dehydrated IL. The structure of the synthesised materials was characterised using powder X-ray diffraction, which confirms the formation of a mixed Na2Ti3O7 and Na2Ti6O13 phase, with majority Na2Ti3O7 phase, in contrast to previous synthesis methods. Scanning and transmission electron microscopy analysis reveals a rod morphology, with an average diameter and length of 87 nm ± 3 nm and 1.37 µm ± 0.07 µm, respectively. The initial discharge and charge capacity of Na2Ti3O7 nanorods were measured as 325.20 mA h g-1 and 149.07 mA h g-1, respectively, at 10 mA g-1 between 0.01-2.5 V. We attribute the enhanced performance to the higher weight fraction of Na2Ti3O7 phase vs. previous reports, demonstrating the potential of the ionic liquid method when applied to sodium titanate materials.

7.
Nat Commun ; 14(1): 3292, 2023 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-37369658

RESUMEN

Age-associated B cells (ABC) accumulate with age and in individuals with different immunological disorders, including cancer patients treated with immune checkpoint blockade and those with inborn errors of immunity. Here, we investigate whether ABCs from different conditions are similar and how they impact the longitudinal level of the COVID-19 vaccine response. Single-cell RNA sequencing indicates that ABCs with distinct aetiologies have common transcriptional profiles and can be categorised according to their expression of immune genes, such as the autoimmune regulator (AIRE). Furthermore, higher baseline ABC frequency correlates with decreased levels of antigen-specific memory B cells and reduced neutralising capacity against SARS-CoV-2. ABCs express high levels of the inhibitory FcγRIIB receptor and are distinctive in their ability to bind immune complexes, which could contribute to diminish vaccine responses either directly, or indirectly via enhanced clearance of immune complexed-antigen. Expansion of ABCs may, therefore, serve as a biomarker identifying individuals at risk of suboptimal responses to vaccination.


Asunto(s)
COVID-19 , Inmunidad Humoral , Humanos , Inhibidores de Puntos de Control Inmunológico , Vacunas contra la COVID-19 , COVID-19/prevención & control , SARS-CoV-2 , Vacunación , Complejo Antígeno-Anticuerpo , Anticuerpos Antivirales
8.
Sci Adv ; 8(35): eabq5206, 2022 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-36044572

RESUMEN

Nucleic acid and histone modifications critically depend on the tricarboxylic acid (TCA) cycle for substrates and cofactors. Although a few TCA cycle enzymes have been reported in the nucleus, the corresponding pathways are considered to operate in mitochondria. Here, we show that a part of the TCA cycle is operational also in the nucleus. Using 13C-tracer analysis, we identified activity of glutamine-to-fumarate, citrate-to-succinate, and glutamine-to-aspartate routes in the nuclei of HeLa cells. Proximity labeling mass spectrometry revealed a spatial vicinity of the involved enzymes with core nuclear proteins. We further show nuclear localization of aconitase 2 and 2-oxoglutarate dehydrogenase in mouse embryonic stem cells. Nuclear localization of the latter enzyme, which produces succinyl-CoA, changed from pluripotency to a differentiated state with accompanying changes in the nuclear protein succinylation. Together, our results demonstrate operation of an extended metabolic pathway in the nucleus, warranting a revision of the canonical view on metabolic compartmentalization.

9.
Traffic ; 9(10): 1581-8, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18557840

RESUMEN

Protein quality control (QC) within the endoplasmic reticulum and the related unfolded protein response (UPR) pathway of signal transduction are major regulators of the secretory pathway, which is involved in virtually any aspect of development and reproduction. The study of plant-specific processes such as pathogen response, seed development and the synthesis of seed storage proteins and of particular toxins is providing novel insights, with potential implications for the general recognition events and mechanisms of action of QC and UPR.


Asunto(s)
Retículo Endoplásmico/metabolismo , Fenómenos Fisiológicos de las Plantas , Proteínas de Plantas/metabolismo , Retículo Endoplásmico/fisiología , Pliegue de Proteína , Vías Secretoras/fisiología , Transducción de Señal , Estrés Fisiológico/fisiología
10.
Proteins ; 74(1): 61-71, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18543330

RESUMEN

The plant hormone indole-3-acetic acid (IAA) is the most abundant natural auxin involved in many aspects of plant development and growth. The IAA levels in plants are modulated by a specific group of amidohydrolases from the peptidase M20D family that release the active hormone from its conjugated storage forms. Here, we describe the X-ray crystal structure of IAA-amino acid hydrolase IAA-leucine resistantlike gene 2 (ILL2) from Arabidopsis thaliana at 2.0 A resolution. ILL2 preferentially hydrolyses the auxin-amino acid conjugate N-(indol-3-acetyl)-alanine. The overall structure of ILL2 is reminiscent of dinuclear metallopeptidases from the M20 peptidase family. The structure consists of two domains, a larger catalytic domain with three-layer alpha beta alpha sandwich architecture and aminopeptidase topology and a smaller satellite domain with two-layer alphabeta-sandwich architecture and alpha-beta-plaits topology. The metal-coordinating residues in the active site of ILL2 include a conserved cysteine that clearly distinguishes this protein from previously structurally characterized members of the M20 peptidase family. Modeling of N-(indol-3-acetyl)-alanine into the active site of ILL2 suggests that Leu175 serves as a key determinant for the amino acid side-chain specificity of this enzyme. Furthermore, a hydrophobic pocket nearby the catalytic dimetal center likely recognizes the indolyl moiety of the substrate. Finally, the active site of ILL2 harbors an absolutely conserved glutamate (Glu172), which is well positioned to act as a general acid-base residue. Overall, the structure of ILL2 suggests that this enzyme likely uses a catalytic mechanism that follows the paradigm established for the other enzymes of the M20 peptidase family.


Asunto(s)
Amidohidrolasas/química , Proteínas de Arabidopsis/química , Arabidopsis/enzimología , Ácidos Indolacéticos/química , Animales , Proteínas Bacterianas/química , Sitios de Unión , Cristalografía por Rayos X , Exopeptidasas/química , Metaloproteasas/química , Modelos Químicos , Estructura Cuaternaria de Proteína , Especificidad por Sustrato
11.
RSC Adv ; 9(70): 40917-40923, 2019 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-35540049

RESUMEN

Cold sintering is a sintering technique which enables ceramic powders to be densified at greatly reduced temperatures compared to traditional solid state techniques, which often require temperatures in excess of 1000 °C. These temperatures often preclude the exploitation of size or orientational effects in ceramics as these are lost during heating. One such effect is the orientation of the crystallographic c axis in YBa2Cu3O7-δ (YBCO) which can be controlled through applied pressure. This effect is of interest for increasing critical current density which is highly dependent on the orientation of the a-b (CuO2) planes within the ceramic. Using cold sintering, we demonstrate that dense YBCO can be created at 180 °C (vs. 1000 °C using solid state) and demonstrate that the likely sintering mechanism is mediated by the cracking which occurs in YBCO when exposed to water. In addition, the ceramics produced show and retain the orientational effect, representing a unique opportunity to study the effect on critical current density. We show that the intergranular critical current when the a-b planes are parallel to the applied field is around 15% higher than when perpendicular.

12.
BMC Genomics ; 8: 431, 2007 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-18036212

RESUMEN

BACKGROUND: Despite the potential of the endoplasmic reticulum (ER) stress response to accommodate adaptive pathways, its integration with other environmental-induced responses is poorly understood in plants. We have previously demonstrated that the ER-stress sensor binding protein (BiP) from soybean exhibits an unusual response to drought. The members of the soybean BiP gene family are differentially regulated by osmotic stress and soybean BiP confers tolerance to drought. While these results may reflect crosstalk between the osmotic and ER-stress signaling pathways, the lack of mutants, transcriptional response profiles to stresses and genome sequence information of this relevant crop has limited our attempts to identify integrated networks between osmotic and ER stress-induced adaptive responses. As a fundamental step towards this goal, we performed global expression profiling on soybean leaves exposed to polyethylene glycol treatment (osmotic stress) or to ER stress inducers. RESULTS: The up-regulated stress-specific changes unmasked the major branches of the ER-stress response, which include enhancing protein folding and degradation in the ER, as well as specific osmotically regulated changes linked to cellular responses induced by dehydration. However, a small proportion (5.5%) of total up-regulated genes represented a shared response that seemed to integrate the two signaling pathways. These co-regulated genes were considered downstream targets based on similar induction kinetics and a synergistic response to the combination of osmotic- and ER-stress-inducing treatments. Genes in this integrated pathway with the strongest synergistic induction encoded proteins with diverse roles, such as plant-specific development and cell death (DCD) domain-containing proteins, an ubiquitin-associated (UBA) protein homolog and NAC domain-containing proteins. This integrated pathway diverged further from characterized specific branches of ER-stress as downstream targets were inversely regulated by osmotic stress. CONCLUSION: The present ER-stress- and osmotic-stress-induced transcriptional studies demonstrate a clear predominance of stimulus-specific positive changes over shared responses on soybean leaves. This scenario indicates that polyethylene glycol (PEG)-induced cellular dehydration and ER stress elicited very different up-regulated responses within a 10-h stress treatment regime. In addition to identifying ER-stress and osmotic-stress-specific responses in soybean (Glycine max), our global expression-profiling analyses provided a list of candidate regulatory components, which may integrate the osmotic-stress and ER-stress signaling pathways in plants.


Asunto(s)
Retículo Endoplásmico/metabolismo , Perfilación de la Expresión Génica/métodos , Glycine max/genética , Hojas de la Planta/genética , Transducción de Señal/genética , ADN Complementario/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Ósmosis , Hojas de la Planta/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/fisiología , Glycine max/metabolismo
13.
J Agric Food Chem ; 54(7): 2629-34, 2006 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-16569054

RESUMEN

Tobacco (Nicotiana tabacum) plants grown from seed obtained by crossing a tobacco line that expressed an activated maize ribosome-inactivating protein (RIP) with a line that overexpressed tobacco anionic peroxidase were tested for their effects on corn earworm Helicoverpa zea and cigarette beetle Lasioderma serricorne larvae as compared to the wild-type plant cross. Significant feeding reductions were noted for transgenic plants expressing both resistance proteins as compared to wild-type plants for both H. zea and L. serricorne. Significant increases in mortality were also noted for those insects fed on the transgenic cross as compared to wild-type plants in some cases. Levels of both peroxidase and maize RIP were significantly higher in transgenic as compared to wild-type plants (which did not produce maize RIP). The degree of feeding was significantly negatively correlated with the level of RIP or peroxidase individually.


Asunto(s)
Nicotiana/genética , Peroxidasas/genética , Control Biológico de Vectores , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Zea mays , Animales , Escarabajos , Lepidópteros , Ribosomas , Nicotiana/enzimología
14.
Sci Rep ; 6: 38696, 2016 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-27924852

RESUMEN

The polyaromatic hydrocarbon coronene has been the molecule of choice for understanding the physical properties of graphene for over a decade. The modelling of the latter by the former was considered to be valid, as since it was first synthesised in 1932, the physical behaviour of coronene has been determined extremely accurately. We recently discovered however, an unforeseen polymorph of coronene, which exists as an enantiotrope with the previously observed crystal structure. Using low-temperature magnetisation and crystallographic measurements, we show here for the first time that the electronic and magnetic properties of coronene depend directly on the temperature at which it is observed, with hysteretic behaviour exhibited between 300 K and 100 K. Furthermore we determine that this behaviour is a direct result of the appearance and disappearance of the newly-discovered polymorph during thermal cycling. Our results not only highlight the need for theoretical models of graphene to take into account this anomalous behaviour at low temperatures, but also explain puzzling experimental observations of coronene dating back over 40 years.

15.
Mol Plant Pathol ; 16(7): 662-74, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25469958

RESUMEN

Aspergillus flavus and Fusarium verticillioides are fungal pathogens that colonize maize kernels and produce the harmful mycotoxins aflatoxin and fumonisin, respectively. Management practice based on potential host resistance to reduce contamination by these mycotoxins has proven difficult, resulting in the need for a better understanding of the infection process by these fungi and the response of maize seeds to infection. In this study, we followed the colonization of seeds by histological methods and the transcriptional changes of two maize defence-related genes in specific seed tissues by RNA in situ hybridization. Maize kernels were inoculated with either A. flavus or F. verticillioides 21-22 days after pollination, and harvested at 4, 12, 24, 48, 72, 96 and 120 h post-inoculation. The fungi colonized all tissues of maize seed, but differed in their interactions with aleurone and germ tissues. RNA in situ hybridization showed the induction of the maize pathogenesis-related protein, maize seed (PRms) gene in the aleurone and scutellum on infection by either fungus. Transcripts of the maize sucrose synthase-encoding gene, shrunken-1 (Sh1), were observed in the embryo of non-infected kernels, but were induced on infection by each fungus in the aleurone and scutellum. By comparing histological and RNA in situ hybridization results from adjacent serial sections, we found that the transcripts of these two genes accumulated in tissue prior to the arrival of the advancing pathogens in the seeds. A knowledge of the patterns of colonization and tissue-specific gene expression in response to these fungi will be helpful in the development of resistance.


Asunto(s)
Aspergillus flavus/patogenicidad , Fusarium/patogenicidad , Semillas/metabolismo , Zea mays/embriología , Zea mays/microbiología
16.
Phytopathology ; 94(1): 82-7, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18943823

RESUMEN

ABSTRACT The maize inbred Tex6 has resistance to colonization and aflatoxin accumulation by Aspergillus flavus. A protein inhibitory to growth of A. flavus has been identified from aqueous extracts of mature Tex6 seeds. This study reports the purification of a chitinase associated with this inhibitory activity to electrophoretic homogeneity and the further characterization of its properties. The inhibitory protein, which has an M(r) of 29,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is an endochitinase that is also capable of exochitinase activity. The enzyme has an optimal pH of 5.5 and a temperature optimum of 45 degrees C. Chitinase activity in maize kernels peaked approximately 36 days after pollination. The Tex6 chitinase purified in this study is capable of inhibiting the growth of A. flavus by 50% at a concentration of 20 mug/ml. Our data indicate that chitinase activity in Tex6 kernels makes a major contribution to the antifungal activity in this maize genotype. Partial peptide sequence of the chitinase showed it to differ from previously reported chitinases.

17.
J Agric Food Chem ; 51(12): 3568-74, 2003 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-12769526

RESUMEN

Progeny of two transgenic tobacco (Nicotiana tabacum L.) lines that expressed an activated form of maize (Zea mays L.) ribosome-inactivating protein (RIP) had varying resistance to the insect species tested. A subset of R(2) plants from the two lines appeared to be more resistant to larvae of the cigarette beetle, Lasioderma serricorne (F.), and the tobacco hornworm, Manduca sexta (L.) than the wild type plants. Progeny (R(3)) of the more resistant R(2) plants were tested more extensively for insect resistance. Resistance to the corn earworm, Helicoverpa zea (Boddie), was most consistent, with significantly decreased feeding often accompanied by increased mortality and reduced weights of survivors fed on leaf disks of the two transgenic lines compared to the wild type. The amount of damage by H. zea was significantly inversely correlated with levels of RIP. Resistance of RIP-producing plants to H. zea was greater than expected on the basis of prior in vitro results using diet-incorporated maize RIP. The R(3) transgenic plant leaf disks were also often more resistant to feeding by larvae of L. serricorne compared to wild type plants. Although reduced feeding by M. sexta was noted when they were fed leaf disks from transgenic compared to wild type plants the first day of exposure, differences were not significant. This information provides further support for maize RIP having a role in resistance to maize-feeding insects.


Asunto(s)
Mariposas Nocturnas , Nicotiana/genética , Nicotiana/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Animales , Escarabajos , Conducta Alimentaria , Larva , Manduca , Extractos Vegetales/genética , Extractos Vegetales/metabolismo , Proteínas Inactivadoras de Ribosomas , Zea mays
18.
Science ; 344(6184): 623-6, 2014 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-24812400

RESUMEN

The growth of metal oxide nanowires can proceed via a number of mechanisms such as screw dislocation, vapor-liquid-solid process, or seeded growth. Transmission electron microscopy (TEM) can resolve nanowires but invariably lacks the facility for direct observation of how nanowires form. We used a transmission electron microscope equipped with an in situ heating stage to follow the growth of quaternary metal oxide nanowires. Video-rate imaging revealed barium carbonate nanoparticles diffusing through a porous matrix containing copper and yttrium oxides to subsequently act as catalytic sites for the outgrowth of Y2BaCuO5 nanowires on reaching the surface. The results suggest that sites on the rough surface of the porous matrix act as microcrucibles and thus provide insights into the mechanisms that drive metal oxide nanowire growth at high temperatures.

19.
Front Microbiol ; 5: 384, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25132833

RESUMEN

Maize kernels are susceptible to infection by the opportunistic pathogen Aspergillus flavus. Infection results in reduction of grain quality and contamination of kernels with the highly carcinogenic mycotoxin, aflatoxin. To understanding host response to infection by the fungus, transcription of approximately 9000 maize genes were monitored during the host-pathogen interaction with a custom designed Affymetrix GeneChip® DNA array. More than 4000 maize genes were found differentially expressed at a FDR of 0.05. This included the up regulation of defense related genes and signaling pathways. Transcriptional changes also were observed in primary metabolism genes. Starch biosynthetic genes were down regulated during infection, while genes encoding maize hydrolytic enzymes, presumably involved in the degradation of host reserves, were up regulated. These data indicate that infection of the maize kernel by A. flavus induced metabolic changes in the kernel, including the production of a defense response, as well as a disruption in kernel development.

20.
Mol Plant Pathol ; 14(9): 898-909, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23834374

RESUMEN

Aspergillus flavus is an opportunistic fungal pathogen that infects maize kernels pre-harvest, creating major human health concerns and causing substantial agricultural losses. Improved control strategies are needed, yet progress is hampered by the limited understanding of the mechanisms of infection. A series of studies were designed to investigate the localization, morphology and transcriptional profile of A. flavus during internal seed colonization. Results from these studies indicate that A. flavus is capable of infecting all tissues of the immature kernel by 96 h after infection. Mycelia were observed in and around the point of inoculation in the endosperm and were found growing down to the germ. At the endosperm-germ interface, hyphae appeared to differentiate and form a biofilm-like structure that surrounded the germ. The exact nature of this structure remains unclear, but is discussed. A custom-designed A. flavus Affymetrix GeneChip® microarray was used to monitor genome-wide transcription during pathogenicity. A total of 5061 genes were designated as being differentially expressed. Genes encoding secreted enzymes, transcription factors and secondary metabolite gene clusters were up-regulated and considered to be potential effector molecules responsible for disease in the kernel. Information gained from this study will aid in the development of strategies aimed at preventing or slowing down A. flavus colonization of the maize kernel.


Asunto(s)
Aspergillus flavus/crecimiento & desarrollo , Aspergillus flavus/genética , Perfilación de la Expresión Génica , Regulación Fúngica de la Expresión Génica , Semillas/microbiología , Transcripción Genética , Zea mays/microbiología , Aspergillus flavus/patogenicidad , Cromosomas Fúngicos/genética , Recuento de Colonia Microbiana , ADN de Hongos/aislamiento & purificación , Electroforesis en Gel de Agar , Endospermo/microbiología , Genes Fúngicos/genética , Humanos , Semillas/citología , Factores de Transcripción/metabolismo , Zea mays/citología
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