RESUMO
Brain metastases are one of the most serious clinical problems in breast cancer (BC) progression, associated with lower survival rates and a lack of effective therapies. Thus, to dissect the early stages of the brain metastatic process, we studied the impact of brain organotropic BC cells' secretomes on the establishment of the brain pre-metastatic niche (PMN). We found that BC cells with specific tropism to the brain caused significant blood-brain barrier (BBB) disruption, as well as microglial activation, in both in vitro and in vivo models. Further, we searched for a brain-organotropic metastatic signature, as a promising source for the discovery of new biomarkers involved in brain metastatic progression. Of relevance, we identified VGF (nerve growth factor inducible) as a key mediator in this process, also impacting the BBB and microglial functions both in vitro and in vivo. In a series of human breast tumors, VGF was found to be expressed in both cancer cells and the adjacent stroma. Importantly, VGF-positive tumors showed a significantly worse prognosis and were associated with HER2 (human epidermal growth factor receptor 2) overexpression and triple-negative molecular signatures. Further clinical validation in primary tumors from metastatic BC cases showed a significant association between VGF and the brain metastatic location, clearly and significantly impacting on the prognosis of BC patients with brain metastasis. In conclusion, our study reveals a unique secretome signature for BC with a tropism for the brain, highlighting VGF as a crucial mediator in this process. Furthermore, its specific impact as a poor prognostic predictor for BC patients with brain metastasis opens new avenues to target VGF to control the progression of brain metastatic disease. © 2024 The Pathological Society of Great Britain and Ireland.
Assuntos
Barreira Hematoencefálica , Neoplasias Encefálicas , Neoplasias da Mama , Humanos , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/metabolismo , Feminino , Barreira Hematoencefálica/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Animais , Linhagem Celular Tumoral , Microglia/metabolismo , Microglia/patologia , Tropismo , Biomarcadores Tumorais/metabolismo , Biomarcadores Tumorais/genética , CamundongosRESUMO
Thin films of ionic liquids (ILs) have gained significant attention due to their unique properties and broad applications. Extensive research has focused on studying the influence of ILs' chemical composition and substrate characteristics on the structure and morphology of IL films at the nano- and mesoscopic scales. This study explores the impact of carbon-coated surfaces on the morphology and wetting behavior of a series of alkylimidazolium-based ILs. Specifically, this work investigates the effect of carbon coating on the morphology and wetting behavior of short-chain ([C2C1im][NTf2] and [C2C1im][OTf]) and long-chain ([C8C1im][NTf2] and [C8C1im][OTf]) ILs deposited on indium tin oxide (ITO), silver (Ag), and gold (Au) substrates. A reproducible vapor deposition methodology was utilized for the deposition process. High-resolution scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy were used to analyze the morphological and structural characteristics of the substrates and obtained IL films. The experimental data revealed that the IL films deposited on carbon-coated Au substrates showed minor changes in their morphology compared to that of the films deposited on clean Au surfaces. However, the presence of carbon coatings on the ITO and Ag surfaces led to significant morphological alterations in the IL films. Specifically, for short-chain ILs, the carbon film surface induced 2D growth of the IL film, followed by subsequent island growth. In contrast, for long-chain ILs deposited on carbon surfaces, layer-by-layer growth occurred without island formation, resulting in highly uniform and coalesced IL films. The extent of morphological changes observed in the IL films was found to be influenced by two crucial factors: the thickness of the carbon film on the substrate surface and the amount of IL deposition.
RESUMO
This study aimed to develop microemulsions (MEs) containing α-bisabolol for the topical treatment of cutaneous leishmaniasis (CL). Initially, pseudoternary phase diagrams were developed using α-bisabolol as the oil phase, Eumulgin® CO 40 as the surfactant, Polymol® HE as the co-surfactant, and distilled water as the aqueous phase. Two transparent liquid systems (TLS) containing 5% of α-bisabolol were selected and characterized (F5E25 and F5EP25). Next, skin permeation and retention assays were performed using Franz cells. The interaction of the formulation with the stratum corneum (SC) was evaluated using the FTIR technique. The cytotoxicity was evaluated in murine peritoneal macrophages. Finally, the antileishmanial activity of microemulsions was determined in promastigotes and amastigotes of L. amazonensis (strain MHOM/BR/77/LTB 0016). As a result, the selected formulations showed isotropy, nanometric size (below 25 nm), Newtonian behavior and pH ranging from 6.5 to 6.9. The MEs achieved a 2.5-fold increase in the flux and skin-permeated amount of α-bisabolol. ATR-FTIR results showed that microemulsions promoted fluidization and extraction of lipids and proteins of the stratum corneum, increasing the diffusion coefficient and partition coefficient of the drug in the skin. Additionally, F5E25 and F5EP25 showed higher activity against promastigotes (IC50 13.27 and 18.29, respectively) compared to unencapsulated α-bisabolol (IC50 53.8). Furthermore, F5E25 and F5EP25 also showed antileishmanial activity against intracellular amastigotes of L. amazonensis, with IC50 50 times lower than free α-bisabolol and high selectivity index (up to 15). Therefore, the systems obtained are favorable to topical administration, with significant antileishmanial activity against L. amazonensis promastigotes and amastigotes, being a promising system for future in vivo trials.
Assuntos
Emulsões , Macrófagos Peritoneais , Sesquiterpenos Monocíclicos , Sesquiterpenos , Pele , Animais , Sesquiterpenos Monocíclicos/farmacologia , Sesquiterpenos Monocíclicos/química , Emulsões/química , Camundongos , Sesquiterpenos/farmacologia , Sesquiterpenos/química , Pele/parasitologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/parasitologia , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/parasitologia , Espectroscopia de Infravermelho com Transformada de Fourier , Absorção Cutânea/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Feminino , Leishmania/efeitos dos fármacos , Tensoativos/farmacologia , Tensoativos/química , Antiprotozoários/farmacologia , Antiprotozoários/químicaRESUMO
Pathology laboratories are increasingly using digital workflows. This has the potential of increasing laboratory efficiency, but the digitization process also involves major challenges. Several reports have been published describing the individual experiences of specific laboratories with the digitization process. However, a comprehensive overview of the lessons learned is still lacking. We provide an overview of the lessons learned for different aspects of the digitization process, including digital case management, digital slide reading, and computer-aided slide reading. We also cover metrics used for monitoring performance and pitfalls and corresponding values observed in practice. The overview is intended to help pathologists, information technology decision makers, and administrators to benefit from the experiences of others and to implement the digitization process in an optimal way to make their own laboratory future-proof.
Assuntos
Processamento de Imagem Assistida por Computador , Patologistas , Humanos , LaboratóriosRESUMO
Two novel tomato-infecting begomoviruses were discovered via high-throughput sequencing in Brazil. Both viruses were also Sanger-sequenced and displayed DNA-A components phylogenetically related to New World bipartite begomoviruses. The names tomato golden net virus (ToGNV) and tomato yellow net virus (ToYNV) were proposed. The majority of the New World begomoviruses has bipartite genomes. However, extensive analyses revealed that ToGNV and ToYNV have monopartite genomes, because no cognate DNA-B components were detected. Hence, they may comprise a unique group of monopartite New World begomoviruses, which have enormous biological, molecular, and plant breeding interest.
Assuntos
Begomovirus , Solanum lycopersicum , Begomovirus/genética , Melhoramento Vegetal , Brasil , Sequenciamento de Nucleotídeos em Larga EscalaRESUMO
The discovery rate of new plant viruses has increased due to studies involving high-throughput sequencing (HTS), particularly for single-stranded DNA viruses of the family Genomoviridae. We carried out an HTS-based survey of genomoviruses in a wide range of native and exotic trees grown in the Brazilian Cerrado biome, and the complete genome sequences of two novel members of the family Genomoviridae from two distinct genera were determined. Specific primers were designed to detect these genomoviruses in individual samples. A new gemykolovirus (Tecoma stans associated gemykolovirus) was detected in Tecoma stans, and a new gemykibivirus (Ouratea duparquetiana associated gemykibivirus) was detected in Ouratea duparquetiana. A gemykrogvirus related to Gila monster associated gemykrogvirus (80% pairwise identity) was also detected in foliar samples of Trembleya parviflora. Our pilot study paves the way for a better characterization of this diverse collection of genomoviruses as well as their interactions with the associated tree species.
Assuntos
Vírus de DNA , Plantas , Vírus de DNA/genética , Brasil , Projetos Piloto , Filogenia , Ecossistema , ÁrvoresRESUMO
Eggplant (Solanum melongena L.) is an economically important vegetable crop in Brazil, especially in family-based farming. Eggplant hybrids 'Ciça' and 'Napoli' (≈ 400 plants) were detected exhibiting virus-like symptoms (5-20% incidence) in field surveys (2015-2018) in Brasília-DF (Figure 1). Symptoms included chlorosis, mosaic and apical leaf deformation. Six symptomatic leaf samples were collected from fruit-bearing plants (around 100 days after planting) aiming at verifying the potential orthotospovirus infection. Double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was carried out with polyclonal antibodies (produced at Centro Nacional de Pesquisa de Hortaliças - CNPH) against the N gene coat protein of the three major orthotospoviruses: tomato spotted wilt orthotospovirus (TSWV), groundnut ringspot orthotospovirus (GRSV) and, tomato chlorotic spot orthotospovirus (TCSV). Strong serological reactions were observed only against GRSV antibodies in the extracts from symptomatic samples, but not in the controls. To confirm the causal agent of those symptoms, total RNA was extracted from infected leaf samples via the standard Trizol® (Sigma) protocol and subsequently used in a two-step reverse transcriptase polymerase chain reaction (RT-PCR) approach. Synthesis of the cDNA was carried out with the J13 primer (5'-CCC GGA TCC AGA GCA AT-3') (Cortez et al., 2001) followed by PCR assays with the primer pair BR60 (5'-AGA GCA ATC GTG TCA-3`) and BR65 (5`-ATC AAG CCT TCT GAA AGT CAT-3') (Eiras et al., 2002). This primer set amplifies a fragment of 453 bp including the 3' untranslated region at the 3' terminus of the S RNA and the protein N-coding gene of at least five species: TSWV, GRSV, TCSV, chrysanthemum stem necrosis orthotospovirus (CSNV) and zucchini lethal chlorosis orthotospovirus (ZLCV). In addition, GRSV-specific primers (LNA Reis, unpublished) were used for amplification of all three segments: L segment: LF/LR (5'-AAC AGG ATT CAG CAA TAT GG-3'/ 5'-AAT TCC TTG AAG ACA ATT GTG T -3'); M segment: MF/MR (5'-TTT GTC CAA CCA TAC CAG ACC C- 3' / 5'-GGC TTC AAT AAA GGC TTG GG-3') and, S segment: SF/SR (5'-TTC AAA CTC AGT TGT ACT CTG A-3'/5'-TTA CTT TCG ATC TGG TTG AA- 3'). Amplicons with 509 bp (MT043204), 289 bp (MT043205), and 901 bp (MT043203) were obtained for L, M and S segments of the eggplant isolate DF-687. PCR amplicons corresponding to a segment of the N-coding gene (396 bp) of a second eggplant isolate (BJL02; MK176337) were obtained with the primer pair BR60/BR65 and subjected to Sanger dideoxy sequencing at CNPH. Alignments of nucleotide sequences of both isolates revealed identity levels varying around 99% to the corresponding genomic regions of a large set of GRSV isolates from GenBank database. PCR assays using total RNA as template yielded 494 bp amplicons solely with GRSV-specific primers (Webster et al., 2011), but no products were obtained with TSWV-specific primers (Adkins and Rosskopf, 2002), confirming the former as the sole causal agent of the field symptoms. Leaves of eggplant cv. 'Ciça' and indicator hosts, including Nicotiana rustica, Capsicum chinense 'PI 159236' (with the Tsw gene), and S. lycopersicum cv. Santa Clara were rub inoculated with extracts prepared from eggplant samples naturally infected with GRSV. Mosaic, necrotic ringspots and systemic leaf deformation symptoms were observed around ten days after inoculation on newly emerged leaves of all inoculated plants. GRSV infection was confirmed by DAS-ELISA and RT-PCR ten days after inoculation. Eggplant was erroneously listed as a host of GRSV in Brazil (Kitajima, 2020). Hence, this is the first report of eggplant infection by this virus in South America. No significant yield losses have been observed in eggplant due to GRSV infection since the overall symptoms are often mild. However, this natural host of GRSV might impact disease management strategies since eggplant is quite often cultivated under family-based farming conditions as a companion crop of highly susceptible tomato, sweet-pepper, and lettuce cultivars. References: Adkins, S., and Rosskopf, E. N. 2002. Plant Dis. 86: 1310. Cortez, I., et al. 2001. Arch. Virol. 146:265. Eiras, M. et al., 2002. Fitopatol. Bras. 27:285. Kitajima, E.W. 2020. Biota Neotrop. 20: e2019932. Webster, C. G., et al. 2011. Virology 413: 216.
RESUMO
Artificial intelligence (AI) solutions that automatically extract information from digital histology images have shown great promise for improving pathological diagnosis. Prior to routine use, it is important to evaluate their predictive performance and obtain regulatory approval. This assessment requires appropriate test datasets. However, compiling such datasets is challenging and specific recommendations are missing. A committee of various stakeholders, including commercial AI developers, pathologists, and researchers, discussed key aspects and conducted extensive literature reviews on test datasets in pathology. Here, we summarize the results and derive general recommendations on compiling test datasets. We address several questions: Which and how many images are needed? How to deal with low-prevalence subsets? How can potential bias be detected? How should datasets be reported? What are the regulatory requirements in different countries? The recommendations are intended to help AI developers demonstrate the utility of their products and to help pathologists and regulatory agencies verify reported performance measures. Further research is needed to formulate criteria for sufficiently representative test datasets so that AI solutions can operate with less user intervention and better support diagnostic workflows in the future.
Assuntos
Inteligência Artificial , Patologia , Humanos , Previsões , Conjuntos de Dados como AssuntoRESUMO
The natural occurrence of mixed infections and large populations of the polyphagous vector (Bemisia tabaci) are the main factors associated with the intensification of the genetic flow among begomoviruses in Neotropical areas, contributing to the emergence of novel recombinants. Here, high-throughput sequencing and metagenomic analyses were employed to discover and characterize a novel recombinant bipartite begomovirus, tentatively named "macroptilium bright yellow interveinal virus" (MaBYIV) in the weed Macroptilium erythroloma (Fabaceae). Recombination signals were detected in MaBYIV, involving bean golden mosaic virus (BGMV) and tomato mottle leaf curl virus (ToMoLCV) genome components. All of the original MaBYIV-infected M. erythroloma plants were found to have mixed infections with BGMV. MaBYIV was transmitted to bean and soybean cultivars via B. tabaci MEAM 1, indicating that M. erythroloma may play a role as a year-round reservoir of a potential new viral pathogen of economically important legume crops.
Assuntos
Begomovirus , Coinfecção , Fabaceae , Begomovirus/genética , DNA Viral/genética , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Doenças das PlantasRESUMO
BACKGROUND: Multidrug-resistant organisms (MDROs) are a reality that can alter the paradigm of treatment and prevention of infection in patients with liver cirrhosis (LC). OBJECTIVE: Identify risk factors for the occurrence of MDROs in patients with LC. PATIENTS AND METHODS: Prospective study from October 2017 to March 2018 in consecutively hospitalized patients with decompensated LC with infection. Blood, urine and ascitic fluid cultures were analyzed. A p-value ≤0.05 was considered statistically significant. RESULTS: MDROs isolated in 18 of 52 episodes of infection. MDROs were associated with the use of proton pump inhibitors (PPIs) (p=0.0312), antibiotic therapy in the last 90 days (p=0.0033) and discharge within preceding 30 days or current hospitalization above 48h (p=0.0082). There was higher 90-day mortality in patients with MDROs infection (71.4% versus 35.7%, p=0.0316). CONCLUSION: MDROs infections were prevalent in this cohort and associated with 90-day mortality. Use of PPIs and antibiotics increased the risk of MDROs infections, suggesting that its prescription should be restricted to formal indication. Hospitalization was associated with the onset of MDROs, so LC patients should stay at the hospital the least possible. It is relevant to investigate other factors predisposing to the emergence of these microorganisms, in order to prevent it.
Assuntos
Infecções Bacterianas/microbiologia , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla , Cirrose Hepática/microbiologia , Antibacterianos/uso terapêutico , Líquido Ascítico/microbiologia , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/mortalidade , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/mortalidade , Feminino , Humanos , Tempo de Internação , Cirrose Hepática/mortalidade , Masculino , Pessoa de Meia-Idade , Alta do Paciente , Estudos Prospectivos , Inibidores da Bomba de Prótons/uso terapêutico , Fatores de Risco , Fatores de TempoRESUMO
Loneliness is a subjective experience escalating worldwide and affecting older adults. Digital solutions can play a major role in addressing loneliness, although its use has been facing resistance due to scarce involvement of older adults in its design. MOAI LABS is an ongoing European project that adopts a co-design process to develop digital solutions to address loneliness in older adults. This study reports the experience of loneliness shared by a group of eight community-dwelling older Portuguese adults (aged 64 to 86 years old), who are "experts by experience" (who feel alone). Findings were obtained from two co-creation sessions that were audio-recorded, and transcribed. The data analysis was performed involving the research team and the "experts by experience." Three themes emerged: 1) loneliness as a detrimental "state of the soul"; 2) loneliness reinforced by features of the aging process; and 3) loneliness builds more loneliness. MOAI LABS co-design process of digital solutions will embrace these experiences and involve frontline gerontological social workers who have experience with older adults' loneliness.
Assuntos
Vida Independente , Solidão , Idoso , Idoso de 80 Anos ou mais , Emoções , Humanos , Estudos Longitudinais , Isolamento SocialRESUMO
Genome size information is sparse across fungi, with information being available for less than 2000 species. So far, most records have been obtained using static, microscope-based cytometry methods or derived from genome sequencing projects. Flow cytometry is now considered the state-of-the-art method for obtaining genome size measurements, and appropriate methods and DNA standards are available, enabling the analysis of most genome size ranges in a rapid, robust and inexpensive way. The average fungal genome size is 60 Mbp, but sizes vary across phylogeny, ranging from 2.2 (Encephalitozoon romaleae) to 3706 Mbp (Jafnea semitosta). In several fungal clades, genome size expansion seems to accompany evolution either to plant mutualism or to plant parasitism (particularly biotrophy), and fungi that interact with plants seem to have larger genomes than saprobes and those that interact with animals. Whereas flow cytometry for nuclear DNA quantification is routinely employed in plant sciences for genome size and ploidy studies, its use in fungal biology is still infrequent. Appropriate standards, methods and best practices are described here, with the aim of stimulating a more generalized and widespread use of flow cytometry for fungal genome size measurement.
Assuntos
Fungos , Genoma de Planta , Animais , Ascomicetos , DNA Fúngico/genética , DNA de Plantas , Encephalitozoon , Citometria de Fluxo , Fungos/genética , Tamanho do GenomaRESUMO
Tomato yellow vein streak virus (ToYVSV) and tomato golden vein virus (TGVV) are begomoviruses reported infecting tomatoes and other hosts across South America. However, their close phylogenetic relationship has generated uncertainties about their taxonomic status and nomenclature. In fact, genomic DNA-A identity levels of isolates reported with an identical virus name may range from 89-100%. In view of the potential inaccuracy regarding the classification status of these viruses (strains vs. distinct species), we carried out a comprehensive set of analyses employing all 45 available isolates with complete DNA-A sequences with either ToYVSV or TGVV designation. Two clear-cut clusters were identified and they were consistent with the current criteria for Begomovirus species demarcation. Moreover, our reappraisal confirmed a large array of misnamed isolates and recognized a distinctive set of virus species-specific genomic, biological, and ecological features. Hence, the present work gives support to the notion that these viruses are closely-related, but they are distinct and valid Begomovirus species. From the breeding standpoint, this information will be useful in guiding germplasm screening strategies searching for sources of large-spectrum resistance to isolates of both viruses.
Assuntos
Begomovirus , Doenças das Plantas/virologia , Solanum lycopersicum/virologia , Begomovirus/classificação , Begomovirus/isolamento & purificação , DNA Viral , Variação Genética , Genoma Viral , Filogenia , América do SulRESUMO
Yield losses induced by a complex of begomoviruses are observed across all major tomato-producing areas in Brazil. Tomato severe rugose virus (ToSRV) is the most widespread begomovirus in the country. Conversely, tomato common mosaic virus (ToCmMV) displays a more restricted geographical distribution to areas associated with the Atlantic Rain Forest (ARF) biome, encompassing the States of Espírito Santo-ES, Minas Gerais-MG, and Rio de Janeiro-RJ. Here, we characterized 277 tomato-infecting isolates collected in fields located within the ARF biome from 2006 to 2018. ToSRV displayed the highest prevalence (n = 157), followed by ToCmMV (n = 95) and tomato interveinal chlorosis virus (n = 14). Four other begomoviruses were also detected, but with very low incidences. ToCmMV was the predominant begomovirus in the ARF biome up to 2014-2015 with very low ToSRV incidence. Subsequently, ToSRV became the most prevalent species in ES and RJ, but ToCmMV was still predominating in the "Zona da Mata" meso-region in MG. Due to the remarkable endemic distribution of ToCmMV, we carried out phylogeographical studies of this virus using information from all 28 available isolates with complete DNA-A sequences. The closest common ancestor of ToCmMV was more likely originated around Coimbra-MG area ≈ 25 years before the formal report of this viral species. So far, all surveys indicated tomatoes as the only natural hosts of ToCmMV with outbreaks occurring mainly (but not exclusively) in highland areas. ToSRV shows a more widespread incidence across both highland and lowland areas of the ARF biome.
Assuntos
Begomovirus , Doenças das Plantas/virologia , Solanum lycopersicum/virologia , Begomovirus/classificação , Begomovirus/genética , Begomovirus/isolamento & purificação , Biodiversidade , Brasil , DNA Viral , Filogeografia , Floresta ÚmidaRESUMO
Malaria is a disease that requires new drugs not only to fight Plasmodium but also to reduce symptoms of infection such as fever and inflammation. A series of 21 hybrid compounds were designed from chloroquine (CQ) and primaquine (PQ) linked to the pharmacophoric group present in phenylacetic anti-inflammatory drugs. These compounds were designed to have dual activity: namely, to be capable of killing Plasmodium and still act on the inflammatory process caused by malaria infection. The compounds were assayed with nine different biological methods. The carbonylated CQ derivative 6 (n = 3; R1 = Cl) was more potent than CQ in vitro, and 8 (n = 4; R1 = H) reduced P. berghei parasitemia up to 37% on day 7. The carbonylated PQ derivative 17 (R = Br) was slightly less potent than PQ. The gem-difluoro PQ derivative 20 (R = Cl) exhibited high transmission blockade of the malaria sporogonic cycle in mosquitoes. Compounds 6 and 20 dose-dependently reduced nitric oxide (NO) production and inhibited TNFα production by LPS-stimulated J774A.1 macrophages. Our results indicate a viable and interesting approach in planning new chemical entities that act as transmission-blocking drugs for treating malaria caused by P. falciparum and P. vivax and the anti-inflammatory process related to this disease.
Assuntos
Anti-Inflamatórios/química , Antimaláricos/farmacologia , Cloroquina/química , Plasmodium/efeitos dos fármacos , Primaquina/química , Animais , Anti-Inflamatórios/farmacologia , Antimaláricos/química , Antimaláricos/uso terapêutico , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Desenho de Fármacos , Eritrócitos/citologia , Eritrócitos/parasitologia , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Malária/tratamento farmacológico , Malária/parasitologia , Malária/patologia , Camundongos , Óxido Nítrico/metabolismo , Relação Estrutura-AtividadeRESUMO
Severe yield losses induced by a complex of whitefly-transmitted Begomovirus species (family Geminiviridae) have been reported in tomatoes in Brazil (Reis et al. 2020). Nine isolates were obtained from tomato plants exhibiting begomovirus-like symptoms (viz. apical and interveinal chlorosis, yellow spots, and stunting) during independent field surveys: one isolate in Sumaré, São Paulo-SP State (isolate SP-066) in 2001, two in Serra Negra, Minas Gerais-MG (MG-012 and MG-016) in 2002, five in Caxias do Sul, Rio Grande do Sul-RS (RS-039, RS-045, RS-046, RS-047 and RS-058) in 2011 and one in Domingos Martins, Espírito Santo-ES (ES-148) in 2016. Disease incidence across all sampled fields ranged from 30% (in Domingos Martins-ES) to 90% in Sumaré-SP. Total DNA extraction was done by a modified CTAB method (Boiteux et al., 1999). Begomovirus infection was confirmed in all isolates by selective amplification of viral DNA-A segments using the primer pairs 'PAL1v1978 / PAR1c496' (Rojas et al., 1993) and 'BegomoAFor1' / 'BegomoARev1' (Ha et al., 2006), which produce two large and non-overlapping segments (≈1120 bp and ≈1205 bp, respectively). These PCR amplicons were initially characterized via direct Sanger dideoxy sequencing at CNPH. BLASTn analysis of the partial DNA-A genomes of these nine isolates indicated identity levels of 95-97% to three euphorbia yellow mosaic virus (EuYMV) reference isolates (= KY559532, JF756674, and KY559583) found infecting the weed Euphorbia heterophylla L. The entire DNA-A (2,609 nts = MN746971) and DNA-B (2,579 nts = MN746970) components of the MG-016 isolate were obtained via high-performance sequencing using Illumina HiSeq 2500 system (Macrogen Inc., South Korea). Sequences were assembled with the CLC Genomics Workbench program 10. Contigs were validated by BLASTx and BLASTn and compared to the ssDNA virus database at NCBI (www.ncbi.nlm.nih.gov). The fully-characterized MG-016 isolate displayed identity levels ranging from 97 to 99% to the EuYMV reference isolates as well as similar genomic features such as the conserved TATA box, nonanucleotide, and iterons (that were in agreement with a cognate nature of the DNA-A and DNA-B components). A partial sequence of the DNA-B genome was also obtained for the MG-012 isolate (MT7831942). The isolates MG-012 and MG-016 were found in mixed infections with tomato severe rugose virus (ToSRV) and tomato golden vein virus (TGVV), respectively. In addition, the complete DNA-A genomes of ES-148 (MN746972) and SP-066 (MN782438) were also obtained via a combination of primer walking and Sanger dideoxy sequencing, displaying 96-98% identity to EuYMV isolates. To our knowledge, this is the first report of multiple and independent events of natural infection of tomatoes by EuYMV isolates. Our results confirm the natural host status of tomatoes to EuYMV isolates as indicated in previous infectivity assays using biolistic inoculation (Barreto et al., 2013). The weed E. heterophylla is widely disseminated and very often present within tomato fields due to its higher levels of tolerance to the major herbicide (metribuzin) employed in this crop. Therefore, this weed may act as a persistent reservoir of tomato-infecting EuYMV isolates, which may allow the selection of viral populations potentially more adapted to this vegetable crop.
RESUMO
The high plasticity of cancer stem-like cells (CSCs) allows them to differentiate and proliferate, specifically when xenotransplanted subcutaneously into immunocompromised mice. CSCs are highly tumorigenic, even when inoculated in small numbers. Thus, in vivo limiting dilution assays (LDA) in mice are the current gold standard method to evaluate CSC enrichment and activity. The chick embryo chorioallantoic membrane (CAM) is a low cost, naturally immune-incompetent and reproducible model widely used to evaluate the spontaneous growth of human tumor cells. Here, we established a CAM-LDA assay able to rapidly reproduce tumor specificities-in particular, the ability of the small population of CSCs to form tumors. We used a panel of organotropic metastatic breast cancer cells, which show an enrichment in a stem cell gene signature, enhanced CD44+/CD24-/low cell surface expression and increased mammosphere-forming efficiency (MFE). The size of CAM-xenografted tumors correlate with the number of inoculated cancer cells, following mice xenograft growth pattern. CAM and mice tumors are histologically comparable, displaying both breast CSC markers CD44 and CD49f. Therefore, we propose a new tool for studying CSC prevalence and function-the chick CAM-LDA-a model with easy handling, accessibility, rapid growth and the absence of ethical and regulatory constraints.
Assuntos
Neoplasias da Mama/patologia , Membrana Corioalantoide , Células-Tronco Neoplásicas/patologia , Animais , Apoptose , Neoplasias da Mama/metabolismo , Movimento Celular , Proliferação de Células , Embrião de Galinha , Feminino , Humanos , Receptores de Hialuronatos/metabolismo , Camundongos , Camundongos Nus , Células-Tronco Neoplásicas/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Sweet potato chlorotic stunt virus (SPCSV; genus Crinivirus, family Closteroviridae), is an economically important pathogen of sweet potato. In the present work, the nucleotide sequences of two RNA segments of SPCSV (isolate SPCSV-UNB-01) were determined by MiSeq Illumina sequencing of samples of sweet potato plants grafted onto Ipomoea setosa. A comparative analysis of the genome organization of SPCSV-UNB-01 and other SPCSV sequences showed that RNA1 was lacking p22, and p5.1 and that p5.2. was absent in RNA2, indicating a unique genomic pattern. SPCSV-UNB-01 contained longer p6 and p5 regions, with little similarity to orthologous sequences. Sequence comparison did not reveal any previously identified functional domains within these open reading frames (ORFs). No recombination or rearrangement events were detected. Phylogenetic analysis suggested the possibility of separate entries of SPCSV into South America based on the genetic distance between SPCSV-UNB-01 and the Peruvian isolate m2-47. Samples from northeastern Brazil (State of Pernambuco) were positive for SPCSV when tested using specific primers for the major coat protein (CP) gene. This is the first full-length genome sequence of SPCSV-UNB-01 from Brazil.
Assuntos
Crinivirus/genética , Crinivirus/isolamento & purificação , Genoma Viral/genética , Brasil , Crinivirus/classificação , Ipomoea batatas/virologia , Fases de Leitura Aberta/genética , Filogenia , Doenças das Plantas/virologia , RNA Viral/genética , Proteínas Virais/genéticaRESUMO
A new bipartite begomovirus (family Geminiviridae) was detected on cowpea (Vigna unguiculata) plants exhibiting bright golden mosaic symptoms on leaves under field conditions in Brazil. Complete consensus sequences of DNA-A and DNA-B components of an isolate of the virus (PE-088) were obtained by nanopore sequencing and confirmed by Sanger sequencing. The genome components presented the typical genomic organization of New World (NW) begomoviruses. Pairwise sequence comparisons revealed low levels of identity with other begomovirus species previously reported infecting cowpea around the world. Phylogenetic analysis using complete sequences of DNA-A components revealed that the closest relatives of PE-088 (85-87% nucleotide sequence identities) were three legume-infecting begomoviruses from Brazil: bean golden mosaic virus, macroptilium common mosaic virus and macroptilium yellow vein virus. According to the current classification criteria, PE-088 represents a new species in the genus Begomovirus, tentatively named as cowpea bright yellow mosaic virus (CoBYMV).
Assuntos
Begomovirus/classificação , Begomovirus/genética , Genoma Viral/genética , Doenças das Plantas/virologia , Folhas de Planta/virologia , Vigna/virologia , Sequência de Bases , Begomovirus/isolamento & purificação , DNA Viral/genética , Filogenia , Análise de Sequência de DNARESUMO
INTRODUCTION: Acute-on-chronic liver failure (ACLF) is a dynamic syndrome that should be assessed repeatedly. An algorithm for risk stratification in decompensated cirrhosis was recently proposed by the EASL-CLIF (European Association for the Study of the Liver-Chronic Liver Failure) Consortium. AIM: To validate the EASL-CLIF Consortium scores in patients with and without ACLF. MATERIALS AND METHODS: Retrospective single-center cohort study including patients admitted for acute decompensation of cirrhosis between January 2014 and December 2015, and followed-up until December 2016. We separated patients with and without ACLF and compared the various EASL-CLIF Consortium scores to Child-Pugh and MELD for predicting 28-day (M28), 90-day and 12-month mortality. These scores were recalculated at different time points over 28 days. RESULTS: 106 patients were included (age 60.3±10.7 years; 87.7% male), 35.8% of whom met ACLF criteria on admission (50%) or during hospitalization. A CLIF-C AD Score ≥60 on admission was associated with a higher risk of developing ACLF. The onset of ACLF during hospitalization portended a poor prognosis. The prognostic performance of the CLIF-C ACLF Score (AUROC for M28: 0.856±0.071) was globally comparable to that of Child-Pugh and MELD. Overall, ACLF resolved in 54.1% patients, resulting in increased survival. Almost 40% of the patients reached their final ACLF grade after ≥8 days, with 13.9% of ACLF patients experiencing resolution by then. DISCUSSION: We confirmed the accuracy and clinical value of the several proposed scores in our population. Prognosis was better defined by the early clinical course than by the initial evaluation, emphasizing the importance of repeated assessments.