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1.
Genes (Basel) ; 12(11)2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34828264

RESUMO

The Plasmodium vivax Cysteine-Rich Protective Antigen (PvCyRPA) has an important role in erythrocyte invasion and has been considered a target for vivax malaria vaccine development. Nonetheless, its genetic diversity remains uncharted in Brazilian malaria-endemic areas. Therefore, we investigated the pvcyrpa genetic polymorphism in 98 field isolates from the Brazilian Amazon and its impact on the antigenicity of predicted B-cell epitopes. Genetic diversity parameters, population genetic analysis, neutrality test and the median-joining network were analyzed, and the potential amino acid polymorphism participation in B-cell epitopes was investigated. One synonymous and 26 non-synonymous substitutions defined fifty haplotypes. The nucleotide diversity and Tajima's D values varied across the coding gene. The exon-1 sequence had greater diversity than those of exon-2. Concerning the prediction analysis, seven sequences were predicted as linear B cell epitopes, the majority contained in conformational epitopes. Moreover, important amino acid polymorphism was detected in regions predicted to contain residues participating in B-cell epitopes. Our data suggest that the pvcyrpa gene presents a moderate polymorphism in the studied isolates and such polymorphisms alter amino acid sequences contained in potential B cell epitopes, an important observation considering the antigen potentiality as a vaccine candidate to cover distinct P. vivax endemic areas worldwide.

2.
J Nematol ; 532021.
Artigo em Inglês | MEDLINE | ID: mdl-34790901

RESUMO

Species of the nematode genus Heterorhabditis are important biological control agents against agricultural pests. The taxonomy of this group is still unclear as it currently relies on phylogenetic reconstructions based on a few genetic markers with little resolutive power, specially of closely related species. To fill this knowledge gap, we sequenced several phylogenetically relevant genetic loci and used them to reconstruct phylogenetic trees, to calculate sequence similarity scores, and to determine signatures of species- and population-specific genetic polymorphism. In addition, we revisited the current literature related to the description, synonymisation, and declaration as species inquirendae of Heterorhabditis species to compile taxonomically relevant morphological and morphometric characters, characterized new nematode isolates at the morphological and morphometrical level, and conducted self-crossing and cross-hybridization experiments. The results of this study show that the sequences of the mitochondrial cytochrome C oxidase subunit I (COI) gene provide better phylogenetic resolutive power than the sequences of nuclear rRNA genes and that this gene marker can phylogenetically resolve closely related species and even populations of the same species with high precision. Using this gene marker, we found two new species, Heterorhabditis ruandica n. sp. and Heterorhabditis zacatecana n. sp. A detailed characterization of these species at the morphological and morphometric levels and nematode reproduction assays revealed that the threshold for species delimitation in this genus, using COI sequences, is 97% to 98%. Our study illustrates the importance of rigorous morphological and morphometric characterization and multi-locus sequencing for the description of new species within the genus Heterorhabditis, serves to clarify the phylogenetic relationships of this important group of biological control agents, and can inform future species descriptions to advance our efforts towards developing more tools for sustainable and environmentally friendly agriculture.

3.
J Chem Ecol ; 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34738202

RESUMO

Most known species of entomopathogenic nematodes (EPNs) are generalist obligate parasites of insects. They kill their hosts within days after infection and mortality is mainly caused by toxins produced by bacteria that co-infect the hosts and serve as food for the nematodes. EPNs can infect a very broad spectrum of insects and these insects can therefore be expected to have evolved strategies to avoid infection. Indeed, ants are known to avoid feeding on EPN-infected insect cadavers, most likely because they are repelled by semiochemicals that emanate from the cadavers. The source and nature of these repellents are so far unknown. In a series of behavioral and chemical analytical experiments we identified hexadecanal and 2-heptadecanone as two compounds that are emitted by insect larva that are infected by the EPN Steinernema feltiae, but not by uninfected larvae. When spiking honey water with the two semiochemicals, they were confirmed to be highly deterrent to the ant Lasius niger. The environmentally benign hexadecanal and 2-heptadecanone could be employed to ward off ants and possibly other pests. Additional experiments are needed to fully determine their application potential.

4.
Ecol Evol ; 11(18): 12596-12604, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34594523

RESUMO

Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) red palm weevils are often reported in association with different organisms including nematodes. The significance of this interaction and whether nematodes can influence their life-history traits is unclear. We collected Rhynchophorus ferrugineus red palm weevils at different developmental stages and locations in Tunisia, observed and dissected them in search for nematodes and other interacting organisms, established laboratory colonies and identified the nematodes associated with them, and conducted nematode-insect interaction assays to determine the capacity of the nematodes to influence their life-history traits. We observed Beauveria bassiana fungi in larvae, nymph, and adults; Centrouropoda and Uroobovella acari associated with the adults, and Teratorhabditis synpapillata nematodes associated with larvae and adults. Nematode-insect interaction bioassays revealed that T. synpapillata nematodes reduce the lifespan of the insect larvae in a population-dependent manner, but do not influence the lifespan of adults. Our study uncovers an important factor that may determine population dynamics of this important palm pests and provides evidence to conclude that these organisms establish a parasitic relationship, rather than a phoretic relationship.

5.
Chem Rec ; 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34669242

RESUMO

The use of laccases applied in bioremediation processes has been increasingly studied, given the urgent need to overcome the environmental problems caused by emerging contaminants. It is known that immobilized enzymes have better operational stability under reaction conditions, allowing for greater applicability. However, given the lack of commercially available immobilized laccases, the search for immobilization materials and methods continues to gain effort. The use of polyacrylonitrile (PAN) to immobilize enzymes has been investigated since it is a low-cost material and can be modified and functionalized to well interact with the enzyme. This polymer can be used with different morphologies such as fibers, beads, and core-shell, presenting as an easily applicable alternative. This review presents the missing link between polymer and enzyme through an overview of PAN's current use as support for laccase immobilization and polymer functionalization methods, considering the importance of immobilized laccases in several industrial sectors.

6.
PLoS One ; 16(10): e0248797, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34669707

RESUMO

Species distribution modelling (SDM) gained importance on biodiversity distribution and conservation studies worldwide, including prioritizing areas for public policies and international treaties. Useful for large-scale approaches and species distribution estimates, it is a plus considering that a minor fraction of the planet is adequately sampled. However, minimizing errors is challenging, but essential, considering the uses and consequences of such models. In situ validation of the SDM outputs should be a key-step-in some cases, urgent. Bioacoustics can be used to validate and refine those outputs, especially if the focal species' vocalizations are conspicuous and species-specific. This is the case of echolocating bats. Here, we used extensive acoustic monitoring (>120 validation points over an area of >758,000 km2, and producing >300,000 sound files) to validate MaxEnt outputs for six neotropical bat species in a poorly-sampled region of Brazil. Based on in situ validation, we evaluated four threshold-dependent theoretical evaluation metrics' ability in predicting models' performance. We also assessed the performance of three widely used thresholds to convert continuous SDMs into presence/absence maps. We demonstrated that MaxEnt produces very different outputs, requiring a careful choice on thresholds and modeling parameters. Although all theoretical evaluation metrics studied were positively correlated with accuracy, we empirically demonstrated that metrics based on specificity-sensitivity and sensitivity-precision are better for testing models, considering that most SDMs are based on unbalanced data. Without independent field validation, we found that using an arbitrary threshold for modelling can be a precarious approach with many possible outcomes, even after getting good evaluation scores. Bioacoustics proved to be important for validating SDMs for the six bat species analyzed, allowing a better refinement of SDMs in large and under-sampled regions, with relatively low sampling effort. Regardless of the species assessing method used, our research highlighted the vital necessity of in situ validation for SDMs.


Assuntos
Quirópteros/fisiologia , Animais , Biodiversidade , Brasil , Ecossistema , Modelos Biológicos , Especificidade da Espécie
7.
Restor Dent Endod ; 46(3): e31, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34513637

RESUMO

Objectives: To evaluate postoperative pain after endodontic treatment of necrotic teeth using large intentional foraminal enlargement (LIFE). Materials and Methods: The sample included 60 asymptomatic necrotic teeth (with or without chronic apical periodontitis), and a periodontal probing depth of 3 mm, previously accessed and referred to perform endodontic treatment. After previous procedures, the position and approximate size of the apical foramen (AF) were determined by using an apex locator and K flexo-files, respectively. The chemomechanical preparation was performed with Profile 04 files 2 mm beyond the AF to achieve the LIFE, using 2.5 mL of 2.5% NaOCl at each file change. The filling was performed by Tagger's hybrid technique and EndoFill sealer. Phone calls were made to all the patients at 24, 48 and 72 hours after treatment, to classify postoperative pain. Statistical analysis was performed by different tests with a significance level of 5%. Results: Age, gender, periradicular status and tooth type did not influence postoperative pain (p > 0.05). Only 1 patient (1.66%) reported severe pain after 72 hours. Moderate pain was reported by 7, 4 and 3 patients after 24, 48 and 72 hours, respectively (p = 0.0001). However, paired analyses showed a statistically significant difference only between 24 and 72 hours (p = 0.04). Sealer extrusion did not influence the postoperative pain (p > 0.05). Conclusions: Acute or moderate postoperative pain was uncommon after endodontic treatment of necrotic teeth with LIFE. Trial Registration: The Brazilian Clinical Trials Registry Identifier: RBR-3r967t.

8.
Int Microbiol ; 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34553287

RESUMO

Soil inhabiting organisms are important determinants of agroecosystem productivity. Understanding the composition, the abundance, and the type of interactions established by soil microorganisms is therefore crucial to design strategies to improve agricultural practices and agroecosystem management. In this study, we collected Zeldia punctata nematodes in maize fields in South Africa and profiled their associated bacterial communities using next-generation sequencing. We observed that Z. punctata nematodes establish associations with ecologically diverse bacterial species. The most abundant species observed are Pseudomonas syringae, a phytopathogenic bacterial complex; Lactobacillus paraplantarum, a broadly distributed bacterial species that is present in soils, water bodies, and animal intestinal tracts and has certain probiotic and antimicrobial properties; and Melissococcus plutonius, a serious pathogenic bacterial species that causes brood disease in honeybees. Our study contributes to a better understanding of the soil bacterial communities associated with nematodes in maize agricultural soils in South Africa and unravels the presence of diverse detrimental and beneficial nematode-associated bacteria.

9.
Artigo em Inglês | MEDLINE | ID: mdl-34524954

RESUMO

Two Gram-negative, rod-shaped bacteria, H1T and H3T, isolated from the digestive tract of Heterorhabditis entomopathogenic nematodes were biochemically and molecularly characterized to determine their taxonomic positions. The 16S rRNA gene sequences of these strains indicate that they belong to the Gammaproteobacteria, to the family Morganellaceae, and to the Photorhabdus genus. Deeper analyses using whole genome-based phylogenetic reconstructions show that strains H1T and H3T are closely related to P. akhurstii DSM 15138T, to P. hainanensis DSM 22397T, and to P. namnaonensis PB45.5T. In silico genomic comparisons confirm these observations and show that strain H1T shares 70.6, 66.8, and 63.5 % digital DNA-DNA hybridization (dDDH) with P. akhurstii DSM 15138T, P. hainanensis DSM 22397T, and P. namnaonensis PB45.5T, respectively, and that strain H3T shares 76.6, 69.4, and 59.2 % dDDH with P. akhurstii DSM 15138T, P. hainanensis DSM 22397T, and P. namnaonensis PB45.5T, respectively. Physiological and biochemical characterization reveals that these two strains differ from most of the validly described Photorhabdus species and from their more closely related taxa. Given the clear phylogenetic separations, that the threshold to discriminate species and subspecies is 70 and 79% dDDH, respectively, and that strains H1T and H3T differ physiologically and biochemically from their more closely related taxa, we propose to classify H1T and H3T into new taxa as follows: H3T as a new subspecies within the species P. akhurstii, and H1T as a new species within the Photorhabdus genus, in spite that H1T shares 70.6 % dDDH with P. akhurstii DSM 15138T, score that is slightly higher than the 70 % threshold that delimits species boundaries. The reason for this is that H1T and P. akhurstii DSM 15138T cluster apart in the phylogenetic trees and that dDDH scores between strain H1T and other P. akhurstii strains are lower than 70 %. Hence, the following names are proposed: Photorhabdus hindustanensis sp. nov. with the type strain H1T (=IARI-SGMG3T,=KCTC 82683T=CCM 9150T=CCOS 1975T) and P. akhurstii subsp. bharatensis subsp. nov. with the type strain H3T (=IARI-SGHR2T=KCTC 82684T=CCM 9149T=CCOS 1976T). These propositions automatically create P. akhurstii subsp. akhurstii subsp. nov. with DSM 15138T as the type strain (currently classified as P. akhurstii).


Assuntos
Nematoides , Photorhabdus , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Photorhabdus/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
10.
Front Pharmacol ; 12: 542342, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34366834

RESUMO

Genetic variability was linked with individual responses to treatment and susceptibility to malaria by Plasmodium vivax. Polymorphisms in the CYP2D6 gene may modulate enzyme level and activity, thereby affecting individual responses to pharmacological treatment. The aim of the study was to investigate whether or not CYP2D6 single nucleotide polymorphisms rs1065852, rs38920-97, rs16947 and rs28371725 are unequally distributed in malaria by Plasmodium vivax individuals from the Brazilian Amazon region. The blood samples were collected from 220 unrelated Plasmodium vivax patients from five different endemic areas. Genotyping was performed using SNaPshot® and real-time polymerase chain reaction methods. In all five areas, the rs1065852 (CYP2D6*10, C.100C > T), rs3892097 (CYP2D6*4, 1846C > T) and rs16947 (CYP2D6*2, C.2850G > A), as a homozygous genotype, showed the lowest frequencies. The rs28371725 (CYP2D6*41, 2988G > A) homozygous genotype was not detected, while the allele A was found in a single patient from Macapá region. No deviations from Hardy-Weinberg equilibrium were found, although a borderline p-value was observed (p = 0.048) for the SNP rs3892097 in Goianésia do Pará, Pará state. No significant associations were detected in these frequencies among the five studied areas. For the SNP rs3892097, a higher frequency was observed for the C/T heterozygous genotype in the Plácido de Castro and Macapá, Acre and Amapá states, respectively. The distribution of the CYP2D6 alleles investigated in the different areas of the Brazilian Amazon is not homogeneous. Further investigations are necessary in order to determine which alleles might be informative to assure optimal drug dosing recommendations based on experimental pharmacogenetics.

11.
Carbohydr Polym ; 272: 118472, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34420731

RESUMO

Chitosan is a biopolymer that is natural, biodegradable, and relatively low price. Chitosan has been attracting interest as a matrix of nanocomposites due to new properties for various applications. This study presents a comprehensive overview of common and recent advances using chitosan as a nanocomposite matrix. The focus is to present alternative processes to produce embedded or coated nanoparticles, and the shaping techniques that have been employed (3D printing, electrospinning), as well as the nanocomposites emerging applications in medicine, tissue engineering, wastewater treatment, corrosion inhibition, among others. There are several reviews about single chitosan material and derivatives for diverse applications. However, there is not a study that focuses on chitosan as a nanocomposite matrix, explaining the possibility of nanomaterial additions, the interaction of the attached species, and the applications possibility following the techniques to combine chitosan with nanostructures. Finally, future directions are presented for expanding the applications of chitosan nanocomposites.

12.
J Chem Ecol ; 47(10-11): 889-906, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34415498

RESUMO

How climate change will modify belowground tritrophic interactions is poorly understood, despite their importance for agricultural productivity. Here, we manipulated the three major abiotic factors associated with climate change (atmospheric CO2, temperature, and soil moisture) and investigated their individual and joint effects on the interaction between maize, the banded cucumber beetle (Diabrotica balteata), and the entomopathogenic nematode (EPN) Heterorhabditis bacteriophora. Changes in individual abiotic parameters had a strong influence on plant biomass, leaf wilting, sugar concentrations, protein levels, and benzoxazinoid contents. Yet, when combined to simulate a predicted climate scenario (Representative Concentration Pathway 8.5, RCP 8.5), their effects mostly counter-balanced each other. Only the sharp negative impact of drought on leaf wilting was not fully compensated. In both current and predicted scenarios, root damage resulted in increased leaf wilting, reduced root biomass, and reconfigured the plant sugar metabolism. Single climatic variables modulated the herbivore performance and survival in an additive manner, although slight interactions were also observed. Increased temperature and CO2 levels both enhanced the performance of the insect, but elevated temperature also decreased its survival. Elevated temperatures and CO2 further directly impeded the EPN infectivity potential, while lower moisture levels improved it through plant- and/or herbivore-mediated changes. In the RCP 8.5 scenario, temperature and CO2 showed interactive effects on EPN infectivity, which was overall decreased by 40%. We conclude that root pest problems may worsen with climate change due to increased herbivore performance and reduced top-down control by biological control agents.

13.
Indian J Dent Res ; 32(1): 104-109, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34269246

RESUMO

Background: The root and canal morphology of maxillary first permanent molars (MFPMs) is a very widely studied issue in endodontics. However, only one study has been conducted to date on this issue using cone-beam computed tomography (CBCT) in India, and the sample consisted of extracted teeth. Aim: To investigate the root and canal morphology of MFPMs in an Indian population, by using CBCT. Methods and Material: 487 bilateral MFPMs (974 teeth) were assessed and the root and canal morphology were determined according to Vertucci's classification. In addition, the prevalence of a second mesiobuccal canal in the mesiobuccal root (MB2) was correlated with gender, age and arch side. Results: Three roots were most commonly found in the MFPMs regardless of gender (P > 0.05), but this prevalence varied according to the side of the dental arch (P < 0.05). MB2 was present in 77.5% of 3-rooted teeth. Patients above 60 years had a higher incidence of these canals (84.7%) (P < .05). The occurrence of bilateral MB2 was 71.8% in 3-rooted MFPMs. Gender had no significant impact on the occurrence of bilateral MB2 in 3-rooted MFPMs (P > .05). The most common canal configuration was type IV (46.5%) and I (98.9%) in the mesiobuccal and distobuccal roots, respectively (P < .05). The prevalence of MB2 in 3-rooted MFPMs was higher in patients above 60 years of age. Conclusions: The root and canal morphology of MFPMs in an Indian population may have significant variations depending on the dental arch side and patient age.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Dente Molar , Cavidade Pulpar/diagnóstico por imagem , Humanos , Índia , Maxila/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Raiz Dentária/diagnóstico por imagem
14.
Aust Endod J ; 2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34146366

RESUMO

This systematic review and meta-analysis was sought to assess whether intentional foraminal enlargement (IFE) is responsible for extrusion of a larger quantity of debris from extracted human teeth with fully formed apexes. Following the recommendations of Preferred Reporting Items for Systematic Review and Meta-Analysis - PRISMA, electronic and manual searches were performed to identify studies that evaluated the extrusion of debris, comparing different apical limits of instrumentation (with/without IFE). The quality of the studies selected was evaluated, and statistical analysis was conducted. To perform the meta-analysis, just 3 papers could be used. The heterogeneity was high, however; there was no statistically significant difference in relation to the extrusion of debris in teeth either submitted or not submitted to IFE. The general risk of bias was moderate. In conclusion, IFE is not responsible for extrusion of a larger quantity of debris from extracted human teeth with fully formed apexes.

15.
Rev. bras. anal. clin ; 53(2): 187-191, 20210630.
Artigo em Português | LILACS | ID: biblio-1352855

Assuntos
COVID-19 , Malária
16.
Elife ; 102021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33875133

RESUMO

Insect herbivores use different cues to locate host plants. The importance of CO2 in this context is not well understood. We manipulated CO2 perception in western corn rootworm (WCR) larvae through RNAi and studied how CO2 perception impacts their interaction with their host plant. The expression of a carbon dioxide receptor, DvvGr2, is specifically required for dose-dependent larval responses to CO2. Silencing CO2 perception or scrubbing plant-associated CO2 has no effect on the ability of WCR larvae to locate host plants at short distances (<9 cm), but impairs host location at greater distances. WCR larvae preferentially orient and prefer plants that grow in well-fertilized soils compared to plants that grow in nutrient-poor soils, a behaviour that has direct consequences for larval growth and depends on the ability of the larvae to perceive root-emitted CO2. This study unravels how CO2 can mediate plant-herbivore interactions by serving as a distance-dependent host location cue.


Assuntos
Dióxido de Carbono/metabolismo , Herbivoria , Mariposas/fisiologia , Zea mays/metabolismo , Animais , Cadeia Alimentar , Larva/crescimento & desenvolvimento , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo
17.
An Acad Bras Cienc ; 93(2): e20201604, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33852672

RESUMO

The Program for Biodiversity Research (PPBio) is an innovative program designed to integrate all biodiversity research stakeholders. Operating since 2004, it has installed long-term ecological research sites throughout Brazil and its logic has been applied in some other southern-hemisphere countries. The program supports all aspects of research necessary to understand biodiversity and the processes that affect it. There are presently 161 sampling sites (see some of them at Supplementary Appendix), most of which use a standardized methodology that allows comparisons across biomes and through time. To date, there are about 1200 publications associated with PPBio that cover topics ranging from natural history to genetics and species distributions. Most of the field data and metadata are available through PPBio web sites or DataONE. Metadata is available for researchers that intend to explore the different faces of Brazilian biodiversity spatio-temporal variation, as well as for managers intending to improve conservation strategies. The Program also fostered, directly and indirectly, local technical capacity building, and supported the training of hundreds of undergraduate and graduate students. The main challenge is maintaining the long-term funding necessary to understand biodiversity patterns and processes under pressure from global environmental changes.


Assuntos
Biodiversidade , Ecossistema , Brasil , Conservação dos Recursos Naturais , Humanos , Conhecimento
18.
Restor Dent Endod ; 46(1): e11, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33680900

RESUMO

Objectives: The aim of this study was to compare smear layer removal by conventional application (CA), passive ultrasonic irrigation (PUI), EasyClean (EC), and XP-Endo Finisher (XPF), using 17% ethylenediaminetetraacetic acid (EDTA) after chemomechanical preparation, as evaluated with scanning electron microscopy (SEM). Materials and Methods: Forty-five single-rooted human mandibular premolars were selected for this study. After chemomechanical preparation, the teeth were randomly divided into 5 groups according to the protocol for smear layer removal, as follows: G1 (control): CA of distilled water; G2 (CA): CA of 17% EDTA; G3 (PUI): 17% EDTA activated by PUI; G4 (EC): 17% EDTA activated by EC; and G5 (XPF): 17% EDTA activated by XPF. SEM images (×1,000) were obtained from each root third and scored by 3 examiners. Data were evaluated using the Kruskal-Wallis and Dunn tests (p < 0.05). Results: In the apical third, there were no statistically significant differences among the groups (p > 0.05). In the cervical and middle thirds, the experimental groups performed better than the control group (p < 0.05); however, G2 presented better results than G3, G4, and G5 (p < 0.05), which showed no differences among one another (p > 0.05). Conclusions: No irrigation method was able to completely remove the smear layer, especially in the apical third. Using CA for the chelating solution performed better than any form of activation.

19.
J Interferon Cytokine Res ; 41(3): 125-131, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33656915

RESUMO

This study aimed at verifying the relationship between the polymorphisms of the cytokines tumor necrosis factor-alpha (TNF-α) -308 G → A (rs1800629); interferon gamma (IFN-γ) +874 T → A (rs2430561); transforming growth factor-beta (TGF-ß) códon 10 (rs1982073) and códon 25 (rs1800471); interleukin (IL)-6 - 174 G → C (rs180079) and IL-10 - 1082 A→T (rs1800896); -819 C → T (rs1800871); -592 A→C (rs1800872); and leprosy. Blood samples were analyzed from 106 individuals, of whom 24 were paucibacillary (PB), 28 were multibacillary (MB), and 54 were patient contacts. Analysis of cytokine polymorphisms was typified by the polymerase chain reaction technique. For TGF-ß +869 T → C and +915 G→C, a tendency to associate the presence of the C allele at codon 10 with leprosy was demonstrated, with the T allele being most frequently found in the CCOSI (P = 0.056). For the polymorphisms IL-10 - 1082 A→T, -819 C→T, and -592 A→C, we found an association of the GCC/GCC genotype with the susceptibility to the disease and the A allele at position 1082 with the leprosy protection. Greater predominance was found of ACC/ATA (31.3%) and GCC/ATA (37.5%) (P = 0.03) and the A allele at position -1082 (76.85%) (P = 0.043) in the CCOSI groups, whereas the GCC/GCC was found in the MB group (22.2%) (P = 0.05). For the other cytokines's single-nucleotide polymorphisms, there were no associations with susceptibility to leprosy. These results are limited by sample size, may not be conclusive, and will need further confirmation in a larger cohort.

20.
Plant Cell Environ ; 44(8): 2672-2686, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33748996

RESUMO

Plant leaves that are exposed to herbivore-induced plant volatiles (HIPVs) respond by increasing their defenses, a phenomenon referred to as priming. Whether this phenomenon also occurs in the roots is unknown. Using maize plants, Zea mays, whose leaves respond strongly to leaf HIPVs, we measured the impact of belowground HIPVs, emanating from roots infested by the banded cucumber beetle, Diabrotica balteata, on constitutive and herbivore-induced levels of defense-related gene expression, phytohormones, volatile and non-volatile primary and secondary metabolites, growth and herbivore resistance in roots of neighbouring plants. HIPV exposure did not increase constitutive or induced levels of any of the measured root traits. Furthermore, HIPV exposure did not reduce the performance or survival of D. balteata on maize or its ancestor teosinte. Cross-exposure experiments between HIPVs from roots and leaves revealed that maize roots, in contrast to maize leaves, neither emit nor respond strongly to defense-regulating HIPVs. Together, these results demonstrate that volatile-mediated defense regulation is restricted to the leaves of maize. This finding is in line with the lower diffusibility of volatiles in the soil and the availability of other, potentially more efficient, information conduits below ground.

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