Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 134
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Plant Dis ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38803068

RESUMO

In October 2023, a Connecticut grower contacted The Connecticut Agricultural Experiment Station about a field of strawberry plants (Fragaria × ananassa) (cv. Ruby June) showing symptoms of severe leaf spotting and visual wilting. Upon visiting the field, leaves had lesions with a diffuse black halo and a light brown center and wilting symptoms, which appeared driven by petiole lesions and presented as dark brown stripes with a reddish-purple halo. Symptoms were observed on 80 to 90% of plants within the block, nearly all of which (>90%) presented with both leaf spots and severe wilting. Diseased tissue was collected from 20 leaves and 25 petioles, sterilized in 0.6% NaOCL, and plated on potato dextrose agar. After hyphal tipping a morphologically identical fungus was isolated from 70% of leaves and 88% of petioles, which formed a dense white mycelial mat with moderate aerial mycelium and conidiomata that exuded dark brown conidial masses. The underside of the mycelial mat was yellowish. Conidia were fusoid, ellipsoid, straight to slightly curved, 4-septate with a single basal appendage and 2-5 apical, matching the description of species within the genus Neopestalotiopsis (Maharachchikumbura et al. 2014). The average conidia (n=74) length, not including appendages, was 29.9 ± 2.1 µm and the average width, at the widest point, was 7.5 ± 0.7 µm. Aerial hyphae were collected from two isolates, CT58-1 and CT62-2, and DNA was extracted for further molecular characterization. PCR was performed with primers targeting actin (ACT), ß-tubulin (TUB2), and ITS prior to amplicon sequencing (Carbone and Kohn 1999; Hassan et al. 2018). Sequences were queried against the NCBI whole genome shotgun database, and aligned sequences from 13 species (including Neopestalotiopsis, Pestalotiopsis, and Pseudopestalotiopsis) were collected for each locus. Sequences were aligned, trimmed, and concatenated using Mega11, and IQ-TREE was employed for model selection (Nguyen et al. 2015; Tamura et al. 2021). A maximum-likelihood tree placed the isolates in a high-confidence cluster with Neopestalotiopsis rosae, confirming this placement of these isolates within the genus (CT58-1 Accession #: PP715979-89; PP707735). To confirm pathogenicity, CT58-1 was grown on autoclaved strawberry leaves to induce sporulation, and a suspension of 105 spores/ml was made. Five milliliters of this spore suspension was sprayed on six 6-week-old strawberries (cv. Jewel), and water was sprayed on the same number of control plants. Plants were at 100% humidity for two days and then kept in the greenhouse for 3 weeks to observe symptoms. Inoculated plants presented with identical leaf spot and petiole lesions to field samples and no visual symptoms were observed on control plants. New isolations were made from infected petioles, which produced morphologically identical spores to those described above, and ITS/ACT loci sequencing yielded sequences identical to those of CT58-1. Spore production and plant inoculations were repeated with this new isolate, and identical symptoms were observed. This is the first report of Neopestalotiopsis infecting strawberries in New England and given the high disease incidence in the initial infected field and relative lack of disease in a neighboring field, it is likely that this pathogen was introduced on bare root plants. As the plants were sourced from a nursery in Ontario, Canada, it is likely that the pathogen is capable of overwintering in the Northeastern United States.

2.
Mol Plant Microbe Interact ; 36(6): 372-380, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36847650

RESUMO

Root-knot nematodes (RKN) (Meloidogyne spp.) represent one of the most damaging groups of plant-parasitic nematodes. They secrete effector proteins through a protrusible stylet to manipulate host cells for their benefit. Stylet-secreted effector proteins are produced within specialized secretory esophageal gland cells, one dorsal gland (DG) and two subventral glands (SvG), whose activity differ throughout the nematode life cycle. Previous gland transcriptomic profiling studies identified dozens of candidate RKN effectors but were focused on the juvenile stages of the nematode, when the SvGs are most active. We developed a new approach to enrich for the active DGs of M. incognita adult female RKN for RNA and protein extraction. Female heads were manually cut from the body, and a combination of sonication and vortexing was used to dislodge contents inside the heads. DG-enriched fractions were collected by filtering, using cell strainers. Comparative transcriptome profiling of pre-parasitic second-stage juveniles, female heads, and DG-enriched samples was conducted using RNA sequencing. Application of an established effector mining pipeline led to the identification of 83 candidate effector genes upregulated in DG-enriched samples of adult females that code for proteins with a predicted signal peptide but lack transmembrane domains or homology to proteins in the free-living nematode Caenorhabditis elegans. In situ hybridization resulted in the identification of 14 new DG-specific candidate effectors expressed in adult females. Taken together, we have identified novel candidate Meloidogyne effector genes that may have essential roles during later stages of parasitism. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Nematoides , Parasitos , Tylenchoidea , Animais , Feminino , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Plantas/genética , Perfilação da Expressão Gênica , Parasitos/genética , Caenorhabditis elegans/genética , Tylenchoidea/genética , Doenças das Plantas/parasitologia
3.
BMC Gastroenterol ; 23(1): 94, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-36977983

RESUMO

BACKGROUND: Evidence indicates that inflammation in Inflammatory Bowel Disease (IBD) is associated with increased systemic levels of reactive oxygen species. Systemic oxidative stress has been associated with reduced levels of plasma thiols. Less invasive tests capable of reflecting and predicting IBD activity are increasingly sought after. We sought to systematically review the evidence inherent in serum thiol levels as a marker of Crohn's Disease and Ulcerative Colitis activity (PROSPERO: CRD42021255521). METHODS: The highest quality documents for systematic reviews standards were used as reference. Articles were searched on Medline via PubMed, VHL, LILACS, WOS, EMBASE, SCOPUS, COCHRANE, CINAHL, OVID, CTGOV, WHO/ICTRP, OPENGREY, BDTD and CAPES, between August, 03 and September, 03 on 2021. Descriptors were defined according to the Medical Subject Heading. Of the 11 articles selected for full reading, 8 were included in the review. It was not possible to perform a pooled analysis of the studies, as there were no combinable studies between subjects with active IBD and controls/inactive disease. RESULTS: Findings from the individual studies included in this review suggest an association between disease activity and systemic oxidation, as measured by serum thiol levels, however, there are limitations that preclude weighting the study results in a meta-analysis. CONCLUSIONS: We recommend conducting better-designed and controlled studies, that include individuals of both phenotypes and at different stages of IBD, involving a larger number of participants, using the standardization of the technique for measuring serum thiols, to confirm whether thiols can be a good parameter for monitoring the clinical course of these intestinal diseases and the degree of clinical applicability.


Assuntos
Colite Ulcerativa , Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Colite Ulcerativa/complicações , Doença de Crohn/complicações , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/complicações , Compostos de Sulfidrila
4.
Anal Chem ; 94(17): 6417-6429, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35348329

RESUMO

The 3D printing (or additive manufacturing, AM) technology is capable to provide a quick and easy production of objects with freedom of design, reducing waste generation. Among the AM techniques, fused deposition modeling (FDM) has been highlighted due to its affordability, scalability, and possibility of processing an extensive range of materials (thermoplastics, composites, biobased materials, etc.). The possibility of obtaining electrochemical cells, arrays, pieces, and more recently, electrodes, exactly according to the demand, in varied shapes and sizes, and employing the desired materials has made from 3D printing technology an indispensable tool in electroanalysis. In this regard, the obtention of an FDM 3D printer has great advantages for electroanalytical laboratories, and its use is relatively simple. Some care has to be taken to aid the user to take advantage of the great potential of this technology, avoiding problems such as solution leakages, very common in 3D printed cells, providing well-sealed objects, with high quality. In this sense, herein, we present a complete protocol regarding the use of FDM 3D printers for the fabrication of complete electrochemical systems, including (bio)sensors, and how to improve the quality of the obtained systems. A guide from the initial printing stages, regarding the design and structure obtention, to the final application, including the improvement of obtained 3D printed electrodes for different purposes, is provided here. Thus, this protocol can provide great perspectives and alternatives for 3D printing in electroanalysis and aid the user to understand and solve several problems with the use of this technology in this field.


Assuntos
Impressão Tridimensional , Protocolos Clínicos , Eletrodos
5.
Mikrochim Acta ; 189(5): 188, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35404013

RESUMO

A laser-induced graphene (LIG) surface modified with Prussian blue (iron hexacyanoferrate) is demonstrated as a novel electrochemical sensing platform for the sensitive and selective detection of hydrogen peroxide. Electrochemical Prussian blue (PB) modification on porous graphene films engraved by infrared laser over flexible polyimide was accomplished. Scanning electron microscopy images combined with Raman spectra confirm the formation of porous graphene and homogenous electrodeposition of PB over this porous surface. Electrochemical impedance spectroscopy reveals a substantial decrease in the resistance to charge transfer values (from 395 to 31.4 Ω) after the PB insertion, which confirms the formation of a highly conductive PB-graphene composite. The synergistic properties of PB and porous graphene were investigated for the constant monitoring of hydrogen peroxide at 0.0 V vs. Ag|AgCl|KCl(sat.), under high-flow injections (166 µL s-1) confirming the high stability of the modified surface and fast response within a wide linear range (from 1 to 200 µmol L-1). Satisfactory detection limit (0.26 µmol L-1) and selectivity verified by the analysis of complex samples confirmed the excellent sensing performance of this platform. We highlight that the outstanding sensing characteristics of the developed sensor were superior in comparison with other PB-based or LIG-based electrochemical sensors reported for hydrogen peroxide detection.


Assuntos
Grafite , Técnicas Eletroquímicas/métodos , Eletrodos , Ferrocianetos , Grafite/química , Peróxido de Hidrogênio/análise , Lasers
6.
Mikrochim Acta ; 189(5): 185, 2022 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-35396635

RESUMO

Graphene-based materials present unique properties for electrochemical applications, and laser-induced conversion of polyimide to graphene is an emerging route to obtain a high-quality material for sensing. Herein we present compact and low-cost equipment constructed from an open-source 3D printer at which a 3.5-W visible (449 nm) laser was adapted to fabricate laser-induced graphene (LIG) electrodes from commercial polyimide, which resulted in electron transfer kinetic (k0) of 5.6 × 10-3 cm s-1 and reproducibility calculated by relative standard deviation (RSD < 5%) from cyclic voltammograms of [Fe(CN)6]3-/4- using 5 different electrodes. LIG electrodes enabled the simultaneous voltammetric determination of uric acid (+ 0.1 V vs. pseudo-reference) and nitrite (+ 0.4 V vs pseudo-reference), with limit of detection (LOD) values of 0.07 and 0.27 µmol L-1, respectively. Amperometric measurements for the detection of H2O2 (applying + 0.0 V vs. Ag|AgCl|KCl(sat.)) after Prussian blue (PB) modification and ciprofloxacin (applying + 1.2 V vs. Ag|AgCl|KCl(sat.)) were performed under flow conditions, which confirmed the high stability of LIG and LIG-PB surfaces. The LOD values were 1.0 and 0.2 µmol L-1 for H2O2 and ciprofloxacin, respectively. The RSD values (< 12%) obtained for the analysis using three different electrodes attested the precision of LIG electrodes manufactured in two designs. No sample matrix effects on the determination of ciprofloxacin in milk samples were observed  (recoveries between 84 and 96%). The equipment can be built with less than $300 and each LIG electrode costs less than $0.01.


Assuntos
Grafite , Ciprofloxacina , Eletrodos , Grafite/química , Peróxido de Hidrogênio , Lasers , Reprodutibilidade dos Testes
7.
J Helminthol ; 96: e20, 2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35257651

RESUMO

The objective of this study was to evaluate the predatory activity of the nematophagous fungus Duddingtonia flagrans on infective larvae of gastrointestinal nematodes from dairy heifers in different conditions (shaded and sunny) of a silvopastoral system (SPS) on an agroecological farm. Ten Jersey heifers were divided into two groups: treated (received pellets containing fungus); and control (received pellets without fungus). Twelve hours after fungus administration, faeces samples were collected for in vitro efficacy tests. The animals then remained for 8 h in the experimental pasture area. At the end of this period, 20 faecal pads (10 treated and 10 control) were selected. Pasture, faecal pad and soil collections occurred at intervals of seven days (d), totalling four assessments over 28 d. To evaluate the influence of the conditions shaded and sunny, we registered the condition of the location of each faecal pad per hour. After 12 h of gastrointestinal transit in dairy heifers, a reduction of 65% was obtained through the in vitro test. The treated group presented a lower number of infective larvae (L3) in the faecal pad and upper pasture. Differences in numbers of L3 were observed between the conditions (sunny and shaded) in the faecal pad of the control group; while in the treated group there were no differences between the conditions. The predatory activity of the fungus was efficient over time in the shaded and sunny conditions of an SPS, decreasing the parasite contamination during the pasture recovery time in a subtropical climate.


Assuntos
Ascomicetos , Duddingtonia , Nematoides , Animais , Bovinos , Fezes/parasitologia , Larva/microbiologia , Nematoides/microbiologia , Controle Biológico de Vetores , Comportamento Predatório
8.
Mol Microbiol ; 114(5): 789-807, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32936940

RESUMO

The fungus Magnaporthe oryzae causes blast, the most devastating disease of cultivated rice. After penetrating the leaf cuticle, M. oryzae grows as a biotroph in intimate contact with living rice epidermal cells before necrotic lesions develop. Biotrophic growth requires maintaining metabolic homeostasis while suppressing plant defenses, but the metabolic connections and requirements involved are largely unknown. Here, we characterized the M. oryzae nucleoside diphosphate kinase-encoding gene NDK1 and discovered it was essential for facilitating biotrophic growth by suppressing the host oxidative burst-the first line of plant defense. NDK enzymes reversibly transfer phosphate groups from tri- to diphosphate nucleosides. Correspondingly, intracellular nucleotide pools were perturbed in M. oryzae strains lacking NDK1 through targeted gene deletion, compared to WT. This affected metabolic homeostasis: TCA, purine and pyrimidine intermediates, and oxidized NADP+ , accumulated in Δndk1. cAMP and glutathione were depleted. ROS accumulated in Δndk1 hyphae. Functional appressoria developed on rice leaf sheath surfaces, but Δndk1 invasive hyphal growth was restricted and redox homeostasis was perturbed, resulting in unsuppressed host oxidative bursts that triggered immunity. We conclude Ndk1 modulates intracellular nucleotide pools to maintain redox balance via metabolic homeostasis, thus quenching the host oxidative burst and suppressing rice innate immunity during biotrophy.


Assuntos
Ascomicetos/metabolismo , Núcleosídeo-Difosfato Quinase/metabolismo , Ascomicetos/genética , Proteínas Fúngicas/metabolismo , Homeostase , Interações Hospedeiro-Patógeno , Hifas/crescimento & desenvolvimento , Imunidade Inata/genética , Núcleosídeo-Difosfato Quinase/genética , Oryza/microbiologia , Oxirredução , Doenças das Plantas/microbiologia
9.
Pain Manag Nurs ; 22(5): 599-604, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34127394

RESUMO

BACKGROUND: Recent studies indicate that the assessment of conditioned pain modulation (CPM) responses and emotional factors can provide important information regarding chronification mechanisms, choices for more efficient therapeutic strategies, and clinical variables supporting a therapeutic prognosis. AIMS: To investigate the impact of nonspecific chronic low back pain (NSCLBP) on CPM and psychosocial factors in individuals with NSCLBP compared with healthy controls. DESIGN: Case-control study. METHODS: Eighteen patients with NSCLBP and 18 healthy controls were recruited for this study. Pain intensity and affective-emotional aspects of pain, functional disability, kinesiophobia, depression, anxiety, and catastrophizing pain were obtained using a questionnaire. A CPM protocol was established to assess the functioning of the descending inhibitory system, with a cold pressor test as a conditioning stimulus and pressure pain threshold as a test stimulus. The maximal isometric strength of the trunk extensors also was evaluated. RESULTS: Healthy participants demonstrated a greater CPM response than those with NSCLBP. Patients with NSCLBP exhibited significantly lower pressure pain threshold than healthy subjects. Moreover, patients with NSCLBP presented with a considerable exacerbation of cognitive-behavioral changes. NSCLBP patients showed diminished maximal isometric strength of the trunk extensor compared to healthy subjects. CONCLUSIONS: The endogenous pain inhibition system is reduced in patients with NSCLBP, with significant cognitive-behavioral changes indicated by high levels of anxiety and moderate pain intensity. SETTING: Clinical School of Physical Therapy of the Federal University of Delta of Parnaíba, Piauí - Brazil. PARTICIPANTS/SUBJECTS: 36 subjects with and without NSCLBP.


Assuntos
Dor Crônica , Dor Lombar , Estudos de Casos e Controles , Catastrofização , Dor Crônica/terapia , Cognição , Humanos , Dor Lombar/terapia , Medição da Dor , Limiar da Dor
10.
J Helminthol ; 95: e31, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34120670

RESUMO

Biological control is a strategy to decrease parasitic populations, and the action takes place through natural antagonists in the environment. We studied the predatory activity of the fungus Duddingtonia flagrans in infective larvae (L3) of gastrointestinal nematodes after gastrointestinal transit. Ten heifers were divided into two groups: treated (animals received pellets containing fungus) and control (animals received pellets without fungus). Twelve hours after administration, faeces samples were collected for in vitro efficacy tests. The animals then remained for 7 h in the experimental pasture area. At the end of this period, 20 faecal pads (ten treated and ten control) were selected at random. Pasture, faecal pad and soil collections occurred with an interval of 7 days, totalling four assessments. In vitro activity demonstrated that fungi effectively preyed on L3, achieving a reduction percentage of 88%. In the faecal pad of the pasture area, there was a difference (P < 0.05) between collections 3 and 4 for both groups; in the treated group a reduction of 65% was obtained, while in the control group there was an increase of 217% in the number of L3. The recovery of L3 in the soil and in the pasture was similar in both groups. There was no influence (P = 0.87) of the passage time on the fungus predatory activity. Duddingtonia flagrans demonstrated the ability to survive gastrointestinal transit in the animals, reducing the number of L3 in the faeces, indicating that this biological control has great potential in the control of worm infections.


Assuntos
Ascomicetos , Agentes de Controle Biológico , Doenças dos Bovinos , Trânsito Gastrointestinal , Nematoides , Infecções por Nematoides , Animais , Bovinos/parasitologia , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/prevenção & controle , Fezes , Feminino , Fungos , Larva , Infecções por Nematoides/prevenção & controle , Infecções por Nematoides/veterinária , Controle Biológico de Vetores
11.
New Phytol ; 226(2): 523-540, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31828801

RESUMO

Fungal phytopathogens can suppress plant immune mechanisms in order to colonize living host cells. Identifying all the molecular components involved is critical for elaborating a detailed systems-level model of plant infection probing pathogen weaknesses; yet, the hierarchy of molecular events controlling fungal responses to the plant cell is not clear. Here we show how, in the blast fungus Magnaporthe oryzae, terminating rice innate immunity requires a dynamic network of redox-responsive E3 ubiquitin ligases targeting fungal sirtuin 2 (Sir2), an antioxidation regulator required for suppressing the host oxidative burst. Immunoblotting, immunopurification, mass spectrometry and gene functional analyses showed that Sir2 levels responded to oxidative stress via a mechanism involving ubiquitination and three antagonistic E3 ubiquitin ligases: Grr1 and Ptr1 maintained basal Sir2 levels in the absence of oxidative stress; Upl3 facilitated Sir2 accumulation in response to oxidative stress. Grr1 and Upl3 interacted directly with Sir2 in a manner that decreased and scaled with oxidative stress, respectively. Deleting UPL3 depleted Sir2 during growth in rice cells, triggering host immunity and preventing infection. Overexpressing SIR2 in the Δupl3 mutant remediated pathogenicity. Our work reveals how redox-responsive E3 ubiquitin ligases in M. oryzae mediate Sir2 accumulation-dependent antioxidation to modulate plant innate immunity and host susceptibility.


Assuntos
Magnaporthe , Oryza , Sirtuínas , Ascomicetos , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Patógeno , Imunidade Inata , Magnaporthe/metabolismo , Oryza/metabolismo , Oxirredução , Doenças das Plantas , Imunidade Vegetal , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
12.
Ann Hepatol ; 19(3): 232-237, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31836424

RESUMO

.: Preventive effect of metformin in hepatocellular carcinoma (HCC) is not entirely clear. We aimed to evaluate the use of metformin as a protective factor of HCC in diabetic patients. .: We carried out an electronic search on PUBMED/MEDLINE, Web of Science and LILACS databases, with no limit of date, from April 2017 to January 2019. Eligible studies included cohort and case-control studies. We adressed data about the use of metformin on the risk of HCC development. Two independent reviewers extracted the data. We evaluated the quality of studies by using the Newcastle-Ottawa scale and carried out a meta-analysis using random-effects models. .: The electronic searches identified 747 studies. After reading abstracts and titles, we excluded 327 duplicated papers and 383 irrelevant references. Eight studies were selected; four case-control and four cohort studies. All studies have observed that the therapy with metformin was associated with a lower risk of HCC, compared with non-metformin therapy. Five articles reported that patients treated with insulin, or insulin secretagogues, presented increased risk of HCC compared to those treated with metformin. One study found that not only statin but also aspirin reduced the risk of HCC, if combined with metformin. A meta-analysis, using the case-control studies, found a combined Odds Ratio of 0.468; 95% CI 0.275-0.799 for the association between HCC and the use of metformin. .: The use of metformin was associated with a reduced risk of HCC, and it may be a relevant factor for preventing HCC in diabetic patients.


Assuntos
Carcinoma Hepatocelular/prevenção & controle , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Neoplasias Hepáticas/prevenção & controle , Metformina/uso terapêutico , Aspirina/uso terapêutico , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Razão de Chances , Inibidores da Agregação Plaquetária/uso terapêutico
13.
Microbiology (Reading) ; 165(11): 1198-1202, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31517594

RESUMO

Following penetration, the devastating rice blast fungus Magnaporthe oryzae, like some other important eukaryotic phytopathogens, grows in intimate contact with living plant cells before causing disease. Cell-to-cell growth during this biotrophic growth stage must involve nutrient acquisition, but experimental evidence for the internalization and metabolism of host-derived compounds is exceedingly sparse. This striking gap in our knowledge of the infection process undermines accurate conceptualization of the plant-fungal interaction. Here, through our general interest in Magnaporthe metabolism and with a specific focus on the signalling and redox cofactor nicotinamide adenine dinucleotide (NAD), we deleted the M. oryzae QPT1 gene encoding quinolinate phosphoribosyltransferase, catalyst of the last step in de novo NAD biosynthesis from tryptophan. We show how QPT1 is essential for axenic growth on minimal media lacking nicotinic acid (NA, an importable NAD precursor). However, Δqpt1 mutant strains were fully pathogenic, indicating de novo NAD biosynthesis is dispensable for lesion expansion following invasive hyphal growth in leaf tissue. Because overcoming the loss of de novo NAD biosynthesis in planta can only occur if importable NAD precursors (which solely comprise the NA, nicotinamide and nicotinamide riboside forms of vitamin B3) are accessible, we unexpectedly but unequivocally demonstrate that vitamin B3 can be acquired from the host and assimilated into Magnaporthe metabolism during growth in rice cells. Our results furnish a rare, experimentally determined example of host nutrient acquisition by a fungal plant pathogen and are significant in expanding our knowledge of events at the plant-fungus metabolic interface.


Assuntos
Magnaporthe/fisiologia , Niacinamida/metabolismo , Oryza/microbiologia , Doenças das Plantas/microbiologia , Meios de Cultura/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Interações Hospedeiro-Patógeno , Magnaporthe/genética , Magnaporthe/metabolismo , Mutação , NAD/metabolismo , Niacina/metabolismo , Niacinamida/análise , Oryza/química , Pentosiltransferases/genética , Pentosiltransferases/metabolismo , Folhas de Planta/química , Folhas de Planta/microbiologia
15.
Metab Brain Dis ; 33(5): 1755-1760, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30014176

RESUMO

To determine the occurrence of diarrhea and associated factors in critically ill patients with traumatic brain injury (TBI) in use of nutritional therapy. Prospective cohort study conducted in an Intensive Care Unit (ICU) of a General Hospital reference in trauma. We evaluated TBI patients who stayed less than 72 h in the ICU, who were using EN for at least 48 h. Definition of diarrhea it was considered three or more episodes of liquid stools or semi-liquid at 24 h. For analysis were evaluated demographic, epidemiological, clinical and nutritional data. Twenty-three patients were evaluated, being 86.9% male, median 33 years old (IQR = 25-52 years) and 16-day ICU stay (IQR = 10-26 days). Diarrhea occurred in 69.6% of the patients and they had a longer time in the ICU (p = 0.007). All patients who used combination prokinetic therapy (metoclopramide and erythromycin) and used antibiotics for more than 8 days had diarrhea (p = 0.057 and p = 0.007, respectively). The incidence of diarrhea was high in TBI patients with enteral nutrition and was associated with the use of antibiotics for more than one week.


Assuntos
Lesões Encefálicas Traumáticas/terapia , Diarreia/epidemiologia , Nutrição Enteral/efeitos adversos , Adulto , Estado Terminal , Diarreia/etiologia , Feminino , Humanos , Incidência , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
16.
Helicobacter ; 22(4)2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28271597

RESUMO

BACKGROUND: The human gastric colonizer Helicobacter pylori is useful to track human migrations given the agreement between the bacterium phylogeographic distribution and human migrations. As Portugal was an African and Brazilian colonizer for over 400 years, we hypothesized that Portuguese isolates were likely genetically closer with those from countries colonized by Portuguese in the past. We aimed to characterize the population structure of several Portuguese-speaking countries, including Portugal, Brazil, Angola, and Cape Verde. MATERIALS AND METHODS: We included strains isolated in Portugal from Portuguese and from former Portuguese colonies. These strains were typed by multilocus sequence typing (MLST) for seven housekeeping genes. We also retrieved from Multi Locus Sequence Typing Web site additional housekeeping gene sequences, namely from Angola and Brazil. RESULTS: We provided evidence that strains from Portuguese belong to hpEurope and that the introgression of hpEurope in non-European countries that speak Portuguese is low, except for Brazil and Cape Verde, where hpEurope accounted for one quarter and one half of the population, respectively. We found genetic similarity for all strains from Portuguese-speaking countries that belong to hpEurope population. Moreover, these strains showed a predominance of ancestral Europe 2 (AE2) over ancestral Europe 1 (AE1), followed by ancestral Africa 1. CONCLUSIONS: H. pylori is a useful marker even for relative recent human migration events and may become rapidly differentiated from founder populations. H. pylori from Portuguese-speaking countries assigned to hpEurope appears to be a hybrid population resulting from the admixture of AE1, AE2 and ancestral hpAfrica1.


Assuntos
Variação Genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/classificação , Helicobacter pylori/genética , Angola , Brasil , Cabo Verde , Genética Populacional , Genótipo , Helicobacter pylori/isolamento & purificação , Migração Humana , Humanos , Tipagem de Sequências Multilocus , Portugal
17.
Helicobacter ; 22(4)2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28436598

RESUMO

BACKGROUND: Helicobacter pylori virulence is associated with different clinical outcomes. The existence of an intact dupA gene from tfs4b cluster has been suggested as a predictor for duodenal ulcer development. However, the role of tfs plasticity zone clusters in the development of ulcers remains unclear. We studied several H. pylori strains to characterize the gene arrangement of tfs3 and tfs4 clusters and their impact in the inflammatory response by infected gastric cells. METHODS: The genome of 14 H. pylori strains isolated from Western patients, pediatric (n=10) and adult (n=4), was fully sequenced using the Illumina platform MiSeq, in addition to eight pediatric strains previously sequenced. These strains were used to infect human gastric cells, and the secreted interleukin-8 (IL-8) was quantified by ELISA. The expression of virB2, dupA, virB8, virB10, and virB6 was assessed by quantitative PCR in adherent and nonadherent fractions of H. pylori during in vitro co-infection, at different pH values. RESULTS: We have found that cagA-positive H. pylori strains harboring a complete tfs plasticity zone cluster significantly induce increased production of IL-8 from gastric cells. We have also found that the region spanning from virB2 to virB10 genes constitutes an operon, whose expression is increased in the adherent fraction of bacteria during infection, as well as in both adherent and nonadherent fractions at acidic conditions. CONCLUSIONS: A complete tfs plasticity zone cluster is a virulence factor that may be important for the colonization of H. pylori and to the development of severe outcomes of the infection with cagA-positive strains.


Assuntos
Aderência Bacteriana , Mucosa Gástrica/imunologia , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/fisiologia , Concentração de Íons de Hidrogênio , Interleucina-8/metabolismo , Adolescente , Adulto , Células Cultivadas , Criança , Células Epiteliais/microbiologia , Feminino , Perfilação da Expressão Gênica , Genes Bacterianos , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/genética , Humanos , Masculino , Pessoa de Meia-Idade , Sequenciamento Completo do Genoma , Adulto Jovem
18.
Exp Parasitol ; 183: 150-159, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28917708

RESUMO

Granulomatous amoebic encephalitis (GAE) is a chronic, difficult to resolve infection caused by amphizoic amoebae of the genus Acanthamoeba, which in most cases occurs in immunosuppressed persons or with chronic diseases such as diabetes. In this study, we describe the early events of A. culbertsoni infection of GAE in diabetic mice model. Diabetes was induced in male BALB/c mice, with a dose of streptozotocin (130 mg/kg). Healthy and diabetic mice were inoculated via intranasal with 1 × 106 trophozoites of A. culbertsoni. Then were sacrificed and fixed by perfusion at 24, 48, 72 and 96 h post-inoculation, the brains and nasopharyngeal meatus were processed to immunohistochemical analysis. Invasion of trophozoites in diabetic mice was significantly greater with respect to inoculated healthy mice. Trophozoites and scarce cysts were immunolocalized in respiratory epithelial adjacent bone tissue, olfactory nerve packets, Schwann cells and the epineurium base since early 24 h post-inoculation. After 48 h, trophozoites were observed in the respiratory epithelium, white matter of the brain, subcortical central cortex and nasopharyngeal associated lymphoid tissue (NALT). At 72 h, cysts and trophozoites were immunolocalized in the olfactory bulb with the presence of a low inflammatory infiltrate characterized by polymorphonuclear cells. Scarce amoebae were observed in the granular layer of the cerebellum without evidence of inflammation or tissue damage. No amoebas were observed at 96 h after inoculation, suggesting penetration to other tissues at this time. In line with this, no inflammatory infiltrate was observed in the surrounding tissues where the amoebae were immunolocalized, which could contribute to the rapid spread of infection, particularly in diabetic mice. All data suggest that trophozoites invade the tissues by separating the superficial cells, penetrating between the junctions without causing cytolytic effect in the adjacent cells and subsequently reaching the CNS, importantly, diabetes increases the susceptibility to amoebae infection, which could favor the GAE development.


Assuntos
Acanthamoeba/patogenicidade , Amebíase/etiologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/complicações , Encefalite/parasitologia , Acanthamoeba/fisiologia , Animais , Encéfalo/parasitologia , Encéfalo/patologia , Cerebelo/parasitologia , Cerebelo/patologia , Suscetibilidade a Doenças , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Nasofaringe/parasitologia , Nasofaringe/patologia , Bulbo Olfatório/parasitologia , Bulbo Olfatório/patologia , Inoculações Seriadas , Trofozoítos , Virulência
19.
Parasitol Res ; 116(2): 725-733, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27915418

RESUMO

This study was developed in order to describe the early morphological events observed during the invasion of two pathogenic strains of Acanthamoeba (genotype T4); A. castellanii and A. culbertsoni, at the olfactory meatus and cerebral, pulmonary, renal, hepatic and splenic tissues levels, an in vivo invasion study. Histological and immunohistochemical description of the events at 24, 48, 72, and 96 h postintranasal inoculations of BALB/c mice was performed. A. castellanii showed a higher invasion rate than A. culbertsoni, which was only able to reach lung and brain tissue in the in vivo model. The current study supports previous evidence of lack of inflammatory response during the early stages of infection. Acanthamoeba invasion of the CNS and other organs is a slow and contact-dependent process. The early morphological events during the invasion of amoebae include the penetration of trophozoites into different epithelia: olfactory, respiratory, alveolar space, and renal tubule, which resemble the process of amoebae invasion described in corneal tissue. The data suggest that after reaching the nasal epithelium, trophozoites continued invasion, separating and lifting the most superficial cells, then migrating and penetrating between the cell junctions without causing a cytolytic effect on adjacent cells. These results reaffirm the idea that contact-dependent mechanisms are relevant for amoebae of Acanthamoeba genus regardless of the invasion site.


Assuntos
Acanthamoeba/patogenicidade , Amebíase/patologia , Sistema Nervoso Central/parasitologia , Túbulos Renais/parasitologia , Mucosa Nasal/parasitologia , Mucosa Respiratória/parasitologia , Trofozoítos/metabolismo , Animais , Córnea/parasitologia , Modelos Animais de Doenças , Genótipo , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C
20.
Water Sci Technol ; 2017(1): 48-57, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29698220

RESUMO

Biopolymers have the ability to form gels that can be used in coagulation/flocculation processes. For this reason, the present work evaluated the application of the Aloe arborescens gel as a biopolymer in the treatment of the effluent generated in galvanic processes. The centesimal, thermogravimetric and texture profiles, as well as the functional groups and the biopolymer's performance in the treatment was analyzed. The performance results were evaluated by central composite rotational design 23. The variables biopolymer concentration, aluminum sulphate and initial pH of the effluent were significant at the confidence level of 95%. The Cr(VI) removal efficiency ranged from 6.37% to 37.74%; significant reductions in dissolved solids (89.80% to 94.13%) and suspended solids (71.06% to 90.00%) were also observed. The treated effluent still presents parameters above the regulatory limits stated by the legislation, therefore, the biopolymer could be used as initial treatment for solids removal.


Assuntos
Aloe/química , Biopolímeros/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Compostos de Alúmen , Cromo/química , Monitoramento Ambiental , Floculação , Purificação da Água/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA