Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 902
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Nat Immunol ; 23(1): 62-74, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34764490

RESUMO

The molecular mechanisms governing orderly shutdown and retraction of CD4+ type 1 helper T (TH1) cell responses remain poorly understood. Here we show that complement triggers contraction of TH1 responses by inducing intrinsic expression of the vitamin D (VitD) receptor and the VitD-activating enzyme CYP27B1, permitting T cells to both activate and respond to VitD. VitD then initiated the transition from pro-inflammatory interferon-γ+ TH1 cells to suppressive interleukin-10+ cells. This process was primed by dynamic changes in the epigenetic landscape of CD4+ T cells, generating super-enhancers and recruiting several transcription factors, notably c-JUN, STAT3 and BACH2, which together with VitD receptor shaped the transcriptional response to VitD. Accordingly, VitD did not induce interleukin-10 expression in cells with dysfunctional BACH2 or STAT3. Bronchoalveolar lavage fluid CD4+ T cells of patients with COVID-19 were TH1-skewed and showed de-repression of genes downregulated by VitD, from either lack of substrate (VitD deficiency) and/or abnormal regulation of this system.


Assuntos
Interferon gama/imunologia , Interleucina-10/imunologia , SARS-CoV-2/imunologia , Células Th1/imunologia , Vitamina D/metabolismo , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Líquido da Lavagem Broncoalveolar/citologia , COVID-19/imunologia , COVID-19/patologia , Complemento C3a/imunologia , Complemento C3b/imunologia , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Ativação Linfocitária/imunologia , Receptores de Calcitriol/metabolismo , Síndrome do Desconforto Respiratório/imunologia , Síndrome do Desconforto Respiratório/patologia , Síndrome do Desconforto Respiratório/virologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/imunologia , Transcrição Gênica/genética
2.
Nature ; 612(7941): 758-763, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36517603

RESUMO

Coronavirus disease 2019 (COVID-19) is known to cause multi-organ dysfunction1-3 during acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with some patients experiencing prolonged symptoms, termed post-acute sequelae of SARS-CoV-2 (refs. 4,5). However, the burden of infection outside the respiratory tract and time to viral clearance are not well characterized, particularly in the brain3,6-14. Here we carried out complete autopsies on 44 patients who died with COVID-19, with extensive sampling of the central nervous system in 11 of these patients, to map and quantify the distribution, replication and cell-type specificity of SARS-CoV-2 across the human body, including the brain, from acute infection to more than seven months following symptom onset. We show that SARS-CoV-2 is widely distributed, predominantly among patients who died with severe COVID-19, and that virus replication is present in multiple respiratory and non-respiratory tissues, including the brain, early in infection. Further, we detected persistent SARS-CoV-2 RNA in multiple anatomic sites, including throughout the brain, as late as 230 days following symptom onset in one case. Despite extensive distribution of SARS-CoV-2 RNA throughout the body, we observed little evidence of inflammation or direct viral cytopathology outside the respiratory tract. Our data indicate that in some patients SARS-CoV-2 can cause systemic infection and persist in the body for months.


Assuntos
Autopsia , Encéfalo , COVID-19 , Especificidade de Órgãos , SARS-CoV-2 , Humanos , Encéfalo/virologia , COVID-19/virologia , RNA Viral/análise , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/patogenicidade , SARS-CoV-2/fisiologia , Replicação Viral , Fatores de Tempo , Sistema Respiratório/patologia , Sistema Respiratório/virologia
3.
Development ; 150(2)2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36714981

RESUMO

The vertebrate eye is shaped as a cup, a conformation that optimizes vision and is acquired early in development through a process known as optic cup morphogenesis. Imaging living, transparent teleost embryos and mammalian stem cell-derived organoids has provided insights into the rearrangements that eye progenitors undergo to adopt such a shape. Molecular and pharmacological interference with these rearrangements has further identified the underlying molecular machineries and the physical forces involved in this morphogenetic process. In this Review, we summarize the resulting scenarios and proposed models that include common and species-specific events. We further discuss how these studies and those in environmentally adapted blind species may shed light on human inborn eye malformations that result from failures in optic cup morphogenesis, including microphthalmia, anophthalmia and coloboma.


Assuntos
Coloboma , Olho , Animais , Humanos , Desenvolvimento Embrionário , Organogênese , Morfogênese/genética , Retina , Mamíferos
4.
Cell ; 141(6): 943-55, 2010 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-20550931

RESUMO

Reprogramming of somatic cells achieved by combination of the four transcription factors Oct4, Sox2, Klf4, and c-Myc has very low efficiency. To increase the reprogramming efficiency and better understand the process, we sought to identify factors that mediate reprogramming with higher efficiency. We established an assay to screen nuclear fractions from extracts of pluripotent mouse cells based on Oct4 reactivation. Using proteomics, we identified components of the ATP-dependent BAF chromatin-remodeling complex, which significantly increases reprogramming efficiency when used together with the four factors. The reprogrammed cells could transmit to the germline and exhibited pluripotency. Reprogramming remained highly efficient when c-Myc was not present but BAF components were overexpressed. BAF complex components mediate this effect by facilitating enhanced Oct4 binding to target promoters during reprogramming. Thus, somatic cell reprogramming using chromatin-remodeling molecules represents an efficient method of generating reprogrammed cells.


Assuntos
Reprogramação Celular , Montagem e Desmontagem da Cromatina , Animais , Linhagem Celular , Cromatina/metabolismo , DNA Helicases/metabolismo , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Perfilação da Expressão Gênica , Fator 4 Semelhante a Kruppel , Camundongos , Proteínas Nucleares/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Fatores de Transcrição/metabolismo
5.
Cell ; 143(4): 617-27, 2010 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-21056461

RESUMO

Embryonic stem cells (ESCs) comprise at least two populations of cells with divergent states of pluripotency. Here, we show that epiblast stem cells (EpiSCs) also comprise two distinct cell populations that can be distinguished by the expression of a specific Oct4-GFP marker. These two subpopulations, Oct4-GFP positive and negative EpiSCs, are capable of converting into each other in vitro. Oct4-GFP positive and negative EpiSCs are distinct from ESCs with respect to global gene expression pattern, epigenetic profile, and Oct4 enhancer utilization. Oct4-GFP negative cells share features with cells of the late mouse epiblast and cannot form chimeras. However, Oct4-GFP positive EpiSCs, which only represent a minor EpiSC fraction, resemble cells of the early epiblast and can readily contribute to chimeras. Our findings suggest that the rare ability of EpiSCs to contribute to chimeras is due to the presence of the minor EpiSC fraction representing the early epiblast.


Assuntos
Camadas Germinativas/citologia , Camundongos/embriologia , Células-Tronco/citologia , Animais , Feminino , Perfilação da Expressão Gênica , Masculino , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Fator 3 de Transcrição de Octâmero/análise , Fator 3 de Transcrição de Octâmero/genética , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo
6.
Am J Pathol ; 193(11): 1809-1816, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-36963628

RESUMO

Ophthalmic manifestations and tissue tropism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported in association with coronavirus disease 2019 (COVID-19), but the pathology and cellular localization of SARS-CoV-2 are not well characterized. The objective of this study was to evaluate macroscopic and microscopic changes and investigate cellular localization of SARS-CoV-2 across ocular tissues at autopsy. Ocular tissues were obtained from 25 patients with COVID-19 at autopsy. SARS-CoV-2 nucleocapsid gene RNA was previously quantified by droplet digital PCR from one eye. Herein, contralateral eyes from 21 patients were fixed in formalin and subject to histopathologic examination. Sections of the droplet digital PCR-positive eyes from four other patients were evaluated by in situ hybridization to determine the cellular localization of SARS-CoV-2 spike gene RNA. Histopathologic abnormalities, including cytoid bodies, vascular changes, and retinal edema, with minimal or no inflammation in ocular tissues were observed in all 21 cases evaluated. In situ hybridization localized SARS-CoV-2 RNA to neuronal cells of the retinal inner and outer layers, ganglion cells, corneal epithelia, scleral fibroblasts, and oligodendrocytes of the optic nerve. In conclusion, a range of common histopathologic alterations were identified within ocular tissue, and SARS-CoV-2 RNA was localized to multiple cell types. Further studies will be required to determine whether the alterations observed were caused by SARS-CoV-2 infection, the host immune response, and/or preexisting comorbidities.


Assuntos
COVID-19 , Humanos , SARS-CoV-2 , Autopsia , RNA Viral/análise , Inflamação
7.
Bioorg Med Chem ; 107: 117756, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38759255

RESUMO

Herein, four silver(I) complexes bearing acetylated d-galactopyranoside-based N-heterocyclic carbene ligands were synthesized and fully characterized by elemental analysis, NMR, and X-ray photoelectron spectroscopy. All complexes were obtained with an anomeric ß-configuration and as monocarbene species. In this study, we investigated the biological effects of the silver(I) complexes 2a-d on the human rhabdomyosarcoma cell line, RD. Our results show concentration-dependent effects on cell density, growth inhibition, and activation of key signaling pathways such as Akt 1/2, ERK 1/2, and p38-MAPK, indicating their potential as anticancer agents. Notably, at 35.5 µM, the complexes induced mitochondrial network disruption, as observed with 2b and 2c, whereas with 2a, this disruption was accompanied by nuclear content release. These results provide insight into the utility of carbohydrate incorporated NHC complexes of silver(I) as new agents in cancer therapy.


Assuntos
Antineoplásicos , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Rabdomiossarcoma , Prata , Humanos , Acetilação , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Relação Dose-Resposta a Droga , Galactose/química , Galactose/farmacologia , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/síntese química , Metano/química , Metano/análogos & derivados , Metano/farmacologia , Metano/síntese química , Estrutura Molecular , Rabdomiossarcoma/tratamento farmacológico , Rabdomiossarcoma/patologia , Prata/química , Prata/farmacologia , Relação Estrutura-Atividade
8.
Cell ; 136(3): 411-9, 2009 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-19203577

RESUMO

The four transcription factors Oct4, Sox2, Klf4, and c-Myc can induce pluripotency in mouse and human fibroblasts. We previously described direct reprogramming of adult mouse neural stem cells (NSCs) by Oct4 and either Klf4 or c-Myc. NSCs endogenously express Sox2, c-Myc, and Klf4 as well as several intermediate reprogramming markers. Here we report that exogenous expression of the germline-specific transcription factor Oct4 is sufficient to generate pluripotent stem cells from adult mouse NSCs. These one-factor induced pluripotent stem cells (1F iPS) are similar to embryonic stem cells in vitro and in vivo. Not only can these cells can be efficiently differentiated into NSCs, cardiomyocytes, and germ cells in vitro, but they are also capable of teratoma formation and germline transmission in vivo. Our results demonstrate that Oct4 is required and sufficient to directly reprogram NSCs to pluripotency.


Assuntos
Células-Tronco Adultas/metabolismo , Fator 3 de Transcrição de Octâmero/metabolismo , Células-Tronco Pluripotentes/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Diferenciação Celular , Células Cultivadas , Reprogramação Celular , Células-Tronco Embrionárias/metabolismo , Células Germinativas/citologia , Fator 4 Semelhante a Kruppel , Antígenos CD15/metabolismo , Camundongos , Miócitos Cardíacos/citologia
9.
J Anim Breed Genet ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38853664

RESUMO

This study utilized Bayesian inference in a genome-wide association study (GWAS) to identify genetic markers associated with traits relevant to the adaptation of Hereford and Braford cattle breeds. We focused on eye pigmentation (EP), weaning hair coat (WHC), yearling hair coat (YHC), and breeding standard (BS). Our dataset comprised 126,290 animals in the pedigree. Out of these, 233 sires were genotyped using high-density (HD) chips, and 3750 animals with medium-density (50 K) single-nucleotide polymorphism (SNP) chips. Employing the Bayes B method with a prior probability of π = 0.99, we identified and tagged single nucleotide polymorphisms (Tag SNPs), ranging from 18 to 117 SNPs depending on the trait. These Tag SNPs facilitated the construction of reduced SNP panels. We then evaluated the predictive accuracy of these panels in comparison to traditional medium-density SNP chips. The accuracy of genomic predictions using these reduced panels varied significantly depending on the clustering method, ranging from 0.13 to 0.65. Additionally, we conducted functional enrichment analysis that found genes associated with the most informative SNP markers in the current study, thereby providing biological insights into the genomic basis of these traits.

10.
Int J Mol Sci ; 25(13)2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-39000438

RESUMO

Strong epigenetic pan-cancer biomarkers are required to meet several current, urgent clinical needs and to further improve the present chemotherapeutic standard. We have concentrated on the investigation of epigenetic alteration of the hTERT gene, which is frequently epigenetically dysregulated in a number of cancers in specific developmental stages. Distinct DNA methylation profiles were identified in our data on early urothelial cancer. An efficient EpihTERT assay could be developed utilizing suitable combinations with sequence-dependent thermodynamic parameters to distinguish between differentially methylated states. We infer from this data set, the epigenetic context, and the related literature that a CpG-rich, 2800 bp region, a prominent CpG island, surrounding the transcription start of the hTERT gene is the crucial epigenetic zone for the development of a potent biomarker. In order to accurately describe this region, we have named it "Acheron" (Ἀχέρων). In Greek mythology, this is the river of woe and misery and the path to the underworld. Exploitation of the DNA methylation profiles focused on this region, e.g., idiolocal normalized Methylation Specific PCR (IDLN-MSP), opens up a wide range of new possibilities for diagnosis, determination of prognosis, follow-up, and detection of residual disease. It may also have broad implications for the choice of chemotherapy.


Assuntos
Biomarcadores Tumorais , Metilação de DNA , Epigênese Genética , Neoplasias , Telomerase , Humanos , Telomerase/genética , Biomarcadores Tumorais/genética , Neoplasias/genética , Neoplasias/tratamento farmacológico , Neoplasias/diagnóstico , Ilhas de CpG , Regulação Neoplásica da Expressão Gênica , Antineoplásicos/uso terapêutico
11.
Int J Mol Sci ; 25(7)2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38612777

RESUMO

High-grade gliomas (HGGs) and glioblastoma multiforme (GBM) are characterized by a heterogeneous and aggressive population of tissue-infiltrating cells that promote both destructive tissue remodeling and aberrant vascularization of the brain. The formation of defective and permeable blood vessels and microchannels and destructive tissue remodeling prevent efficient vascular delivery of pharmacological agents to tumor cells and are the significant reason why therapeutic chemotherapy and immunotherapy intervention are primarily ineffective. Vessel-forming endothelial cells and microchannel-forming glial cells that recapitulate vascular mimicry have both infiltration and destructive remodeling tissue capacities. The transmembrane protein TMEM230 (C20orf30) is a master regulator of infiltration, sprouting of endothelial cells, and microchannel formation of glial and phagocytic cells. A high level of TMEM230 expression was identified in patients with HGG, GBM, and U87-MG cells. In this study, we identified candidate genes and molecular pathways that support that aberrantly elevated levels of TMEM230 play an important role in regulating genes associated with the initial stages of cell infiltration and blood vessel and microchannel (also referred to as tumor microtubule) formation in the progression from low-grade to high-grade gliomas. As TMEM230 regulates infiltration, vascularization, and tissue destruction capacities of diverse cell types in the brain, TMEM230 is a promising cancer target for heterogeneous HGG tumors.


Assuntos
Glioblastoma , Glioma , Doença de Parkinson , Humanos , Glioblastoma/genética , Proteínas de Membrana/genética , Células Endoteliais , Angiogênese , Glioma/genética , Neuroglia , Neovascularização Patológica/genética
12.
Molecules ; 29(4)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38398508

RESUMO

Tryptophan synthase (TRPS) is a complex enzyme responsible for tryptophan biosynthesis. It occurs in bacteria, plants, and fungi as an αßßα heterotetramer. Although encoded by independent genes in bacteria and plants, in fungi, TRPS is generated by a single gene that concurrently expresses the α and ß entities, which are linked by an elongated peculiar segment. We conducted 1 µs all-atom molecular dynamics simulations on Hemileia vastatrix TRPS to address two questions: (i) the role of the linker segment and (ii) the comparative mode of action. Since there is not an experimental structure, we started our simulations with homology modeling. Based on the results, it seems that TRPS makes use of an already-existing tunnel that can spontaneously move the indole moiety from the α catalytic pocket to the ß one. Such behavior was completely disrupted in the simulation without the linker. In light of these results and the αß dimer's low stability, the full-working TRPS single genes might be the result of a particular evolution. Considering the significant losses that Hemileia vastatrix causes to coffee plantations, our next course of action will be to use the TRPS to look for substances that can block tryptophan production and therefore control the disease.


Assuntos
Basidiomycota , Simulação de Dinâmica Molecular , Triptofano Sintase , Triptofano Sintase/química , Triptofano Sintase/genética , Triptofano Sintase/metabolismo , Triptofano , Fungos/metabolismo
13.
Antimicrob Agents Chemother ; 67(6): e0017223, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37133362

RESUMO

A novel Bayesian method was developed to interpret serum vancomycin concentrations (SVCs) following the administration of one or more vancomycin doses with potential varying doses and intervals based on superposition principles. The method was evaluated using retrospective data from 442 subjects from three hospitals. The patients were required to receive vancomycin for more than 3 days, have stable renal function (fluctuation in serum creatinine of ≤0.3 mg/dL), and have at least 2 trough concentrations reported. Pharmacokinetic parameters were predicted using the first SVC, and the fitted parameters were then used to predict subsequent SVCs. Using only covariate-adjusted population prior estimates, the first two SVC prediction errors were 47.3 to 54.7% for the scaled mean absolute error (sMAE) and 62.1 to 67.8% for the scaled root mean squared error (sRMSE). "Scaled" refers to the division of the MAE or RMSE by the mean value. The Bayesian method had minimal errors for the first SVC (by design), and for the second SVC, the sMAE was 8.95%, and the sRMSE was 36.5%. The predictive performance of the Bayesian method did degrade with subsequent SVCs, which we attributed to time-dependent pharmacokinetics. The 24-h area under the concentration-time curve (AUC) was determined from simulated concentrations before and after the first SVC was reported. Prior to the first SVC, 170 (38.4%) patients had a 24-h AUC of <400 mg · h/L, 186 (42.1%) had a 24-h AUC within the target range, and 86 (19.5%) had a 24-h AUC of >600 mg · h/L. After the first SVC was reported, 322 (72.9%) had a 24-h AUC within the target range, 68 (15.4%) had low values, and 52 (11.8%) had high values based on the model simulation. Target attainments were 38% before the first SVC and 73% after the first SVC. The hospitals had no policies or procedures in place for targeting 24-h AUCs, although the trough target was typically 13 to 17 mg/L. Our data provide evidence of time-dependent pharmacokinetics, which will require regular therapeutic drug monitoring regardless of the method used to interpret SVCs.


Assuntos
Monitoramento de Medicamentos , Vancomicina , Humanos , Teorema de Bayes , Estudos Retrospectivos , Área Sob a Curva , Monitoramento de Medicamentos/métodos , Antibacterianos
14.
PLoS Pathog ; 17(4): e1009431, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33831133

RESUMO

Tracking evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within infected individuals will help elucidate coronavirus disease 2019 (COVID-19) pathogenesis and inform use of antiviral interventions. In this study, we developed an approach for sequencing the region encoding the SARS-CoV-2 virion surface proteins from large numbers of individual virus RNA genomes per sample. We applied this approach to the WA-1 reference clinical isolate of SARS-CoV-2 passaged in vitro and to upper respiratory samples from 7 study participants with COVID-19. SARS-CoV-2 genomes from cell culture were diverse, including 18 haplotypes with non-synonymous mutations clustered in the spike NH2-terminal domain (NTD) and furin cleavage site regions. By contrast, cross-sectional analysis of samples from participants with COVID-19 showed fewer virus variants, without structural clustering of mutations. However, longitudinal analysis in one individual revealed 4 virus haplotypes bearing 3 independent mutations in a spike NTD epitope targeted by autologous antibodies. These mutations arose coincident with a 6.2-fold rise in serum binding to spike and a transient increase in virus burden. We conclude that SARS-CoV-2 exhibits a capacity for rapid genetic adaptation that becomes detectable in vivo with the onset of humoral immunity, with the potential to contribute to delayed virologic clearance in the acute setting.


Assuntos
COVID-19 , Epitopos , Imunidade Humoral , Mutação , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , COVID-19/genética , COVID-19/imunologia , Linhagem Celular , Epitopos/genética , Epitopos/imunologia , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
15.
Nat Chem Biol ; 17(1): 47-56, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32807969

RESUMO

Identifying molecular and cellular processes that regulate reprogramming competence of transcription factors broadens our understanding of reprogramming mechanisms. In the present study, by a chemical screen targeting major epigenetic pathways in human reprogramming, we discovered that inhibiting specific epigenetic roadblocks including disruptor of telomeric silencing 1-like (DOT1L)-mediated H3K79/K27 methylation, but also other epigenetic pathways, catalyzed by lysine-specific histone demethylase 1A, DNA methyltransferases and histone deacetylases, allows induced pluripotent stem cell generation with almost all OCT factors. We found that simultaneous inhibition of these pathways not only dramatically enhances reprogramming competence of most OCT factors, but in fact enables dismantling of species-dependent reprogramming competence of OCT6, NR5A1, NR5A2, TET1 and GATA3. Harnessing these induced permissive epigenetic states, we performed an additional screen with 98 candidate genes. Thereby, we identified 25 transcriptional regulators (OTX2, SIX3, and so on) that can functionally replace OCT4 in inducing pluripotency. Our findings provide a conceptual framework for understanding how transcription factors elicit reprogramming in dependency of the donor cell epigenome that differs across species.


Assuntos
Reprogramação Celular , Epigênese Genética , Histona-Lisina N-Metiltransferase/genética , Histonas/genética , Células-Tronco Embrionárias Humanas/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Animais , Linhagem Celular , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Proteínas do Olho/genética , Proteínas do Olho/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Células HEK293 , Células HeLa , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Células-Tronco Embrionárias Humanas/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fatores de Transcrição de Octâmero/genética , Fatores de Transcrição de Octâmero/metabolismo , Fatores de Transcrição Otx/genética , Fatores de Transcrição Otx/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Especificidade da Espécie , Transcrição Gênica , Transfecção , Proteína Homeobox SIX3
16.
Ecol Appl ; 33(3): e2800, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36546663

RESUMO

Livestock production in drylands requires consideration of the ecological applications of ecohydrological redistribution of water. Intensive cattle trampling and the associated increase of surface runoff are common concerns for rangeland productivity and sustainability. Here, we highlight a regional livestock production system in which cattle trails and trampling surrounding an artificial impoundment are purposely managed to enhance redistribution and availability of water for cattle drinking. Based on literature synthesis and field measurements, we first describe cattle production systems and surface water redistribution in the Dry Chaco rangelands of South America, and then develop a conceptual framework to synthesize the ecohydrological impacts of livestock production on these ecosystems. Critical to this framework is the pioshere-a degraded overgrazed and overtrampled area where vegetation has difficulties growing, usually close to the water points. The Dry Chaco rangelands have three key distinctive characteristics associated with the flat sedimentary environment lacking fresh groundwater and the very extensive ranching conditions: (1) cattle drinking water is provided by artificial impoundments filled by runoff, (2) heavy trampling around the impoundment and its adjacent areas generates a piosphere that favors runoff toward the impoundment, and (3) the impoundment, piosphere, and extensive forage areas are hydrologically connected with a network of cattle trails. We propose an ecohydrological framework where cattle transit and trampling alter the natural water circulation of these ecosystems, affecting small fractions of the landscape through increased runoff (compaction in piosphere and trails), surface connectivity (convergence of trails to piosphere to impoundment), and ponding (compaction of the impoundment floor) that operate together making water harvesting and storage possible. These effects have likely generated a positive water feedback on the expansion of livestock in the region with a relatively low impact on forage production. We highlight the role of livestock transit as a geomorphological agent capable of reshaping the hydrology of flat sedimentary rangelands in ways that can be managed positively for sustainable ranching systems. We suggest that the Dry Chaco offers an alternative paradigm for rangelands in which cattle trampling may contribute to sustainable seminatural production systems with implications for other dry and flat rangelands of the world.


Assuntos
Ecossistema , Gado , Animais , Bovinos , Água , Hidrologia , América do Sul
17.
An Acad Bras Cienc ; 95(3): e20220779, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37937616

RESUMO

Sulzbacheromyces is a genus of basidiolichen that includes nine species scattered on the African, American, and Asian continents. Sequences of the universal barcode of Fungi, the nuclear internal transcribed spacer - nuITS region, are available to all known species of the genus. Specimens of Sulzbacheromyces caatingae were collected during two expeditions in the Morro of Paxixi, Mato Grosso do Sul state, Midwest region of Brazil, in the Cerrado biome, where it was reported for the first time to the state. Morphological and anatomical analyses were performed. Specimens from Mato Grosso do Sul have a light green to indistinct thallus, while specimens from Ceará, Paraíba, and Piauí states present a thin green crust on the substrate. The nuITS sequences were also generated, and the distribution of S. caatingae was plotted with the haplotypes. Morphological differences were not reflected in the molecular analysis, which confirmed the identification of the species. In addition, an identification key to the known Sulzbacheromyces species is provided.


Assuntos
Basidiomycota , Ecossistema , Brasil , Basidiomycota/genética
18.
Rev Sci Tech ; 42: 201-209, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37232304

RESUMO

In 2015, the World Organisation for Animal Health (WOAH, founded as OIE) initiated the annual collection of data on antimicrobials intended for use in animals using a Microsoft Excel questionnaire. In 2022, WOAH initiated the migration to a customised interactive online system: ANIMUSE Global Database. This system enables national Veterinary Services not only to monitor and report data more easily and more accurately, but also to visualise, analyse and use data for surveillance purposes to their own benefit in the implementation of national action plans on antimicrobial resistance. This journey started seven years ago, with progressive improvements in the way data are collected, analysed and reported and continuous adaptations to overcome various challenges encountered (e.g. data confidentiality, training of civil servants, calculation of active ingredients, standardisation to enable fair comparisons and trend analyses, and data interoperability). Technical developments have been key in the success of this endeavour. However, it is important not to underestimate the importance of the human element: to listen to WOAH Members and their needs, and to exchange to solve issues, adapt tools, and gain and maintain trust. The journey is not over yet, and more developments are foreseen, such as to complement current data sources with data collected directly at the farm level; strengthen interoperability and integrated analysis with cross-sectoral databases; and facilitate institutionalisation of data collection and systematic use in monitoring, evaluation, lesson learning, reporting and, eventually, surveillance of antimicrobial use and antimicrobial resistance when implementing and updating national action plans. This paper describes how all these challenges were overcome and how future challenges will be addressed.


En 2015, l'Organisation mondiale de la santé animale (OMSA, fondée en tant qu'OIE) a démarré, au moyen d'un questionnaire Microsoft Excel, une collecte annuelle de données sur les agents antimicrobiens destinés à être utilisés chez les animaux. L'OMSA a engagé, en 2022, la migration de cette collecte vers un système interactif en ligne sur mesure : la base de données mondiale ANIMUSE. Grâce à ce système, les Services vétérinaires pourront non seulement suivre et faire remonter les données plus facilement et avec davantage de précision, mais ils pourront aussi visualiser, analyser et utiliser ces données à leurs propres fins de surveillance, dans le cadre de la mise en oeuvre de plans d'action nationaux sur la résistance aux antimicrobiens. Ce travail a commencé il y a sept ans et des progrès constants ont été enregistrés en termes de collecte, d'analyse et de notification des données ; des adaptations continues ont également permis de dépasser les différents défis rencontrés (par exemple, en termes de confidentialité des données, de formation des fonctionnaires, de calcul des ingrédients actifs, de normalisation permettant d'établir des comparaisons équitables et des analyses de tendances et d'interopérabilité des données). Les avancées techniques ont joué un rôle clé dans la réussite de cette initiative. Il est cependant essentiel de ne pas sous-estimer l'importance du facteur humain : écoute des Membres de l'OMSA et de leurs besoins, échanges afin de résoudre les problèmes, adaptation des outils et obtention et préservation de la confiance. Cette aventure n'est pas terminée et des évolutions sont à venir : ajout des données collectées directement au niveau des élevages parmi les sources de données actuelles ; renforcement de l'interopérabilité et de l'analyse intégrée en recourant aux bases de données intersectorielles ; et institutionnalisation de la collecte de données et de son usage systématique dans le suivi, l'évaluation, les enseignements, les notifications et, à terme, la surveillance de l'utilisation des agents antimicrobiens et de l'antibiorésistance lors du déploiement et de la mise à jour des plans d'action nationaux. Cet article décrit comment tous ces défis ont été surmontés, ainsi que la manière dont les futurs défis seront relevés.


En 2015, la Organización Mundial de Sanidad Animal (OMSA, fundada como OIE) implantó un sistema de obtención anual de datos sobre los productos antimicrobianos destinados a los animales, empleando para ello un cuestionario en forma de hoja de cálculo Excel. En 2022, la OMSA inició la migración de este dispositivo a un sistema interactivo en línea especialmente adaptado al efecto: la base de datos mundial ANIMUSE. Este sistema permite a los Servicios Veterinarios nacionales no solo obtener y notificar datos con más facilidad y exactitud, sino también visualizar, analizar y aprovechar esta información con fines de vigilancia en la aplicación de planes nacionales de acción sobre la resistencia a antimicrobianos. Este viaje, que empezó hace siete años, ha supuesto una progresiva mejora de los métodos de obtención, análisis y notificación de los datos y continuas adaptaciones para superar las diversas dificultades que iban surgiendo (p.ej. en cuanto a confidencialidad de los datos, formación de funcionarios, cálculo de las cantidades de principio activo, normalización con fines de comparación y de análisis de tendencias, o compatibilidad de los datos). Aunque los avances técnicos han sido fundamentales para el éxito de la empresa, no cabe subestimar la importancia del factor humano, ese empeño de escuchar a los Miembros de la OMSA y tener en cuenta sus necesidades, favorecer el intercambio para resolver problemas, adaptar las herramientas y forjar y mantener relaciones de confianza. El viaje aún no ha terminado. Previsiblemente habrá nuevos avances que permitan, por ejemplo, complementar las actuales fuentes de información con datos obtenidos directamente en la explotación, mejorar la compatibilidad y los análisis integrados con bases de datos intersectoriales, o institucionalizar en mayor medida la obtención de datos y su uso sistemático con fines de seguimiento, evaluación, aprendizaje, notificación y a la postre vigilancia del uso de antimicrobianos y de eventuales resistencias a la hora de aplicar o actualizar planes nacionales de acción. Los autores explican cómo se fueron superando todas esas dificultades y cómo se abordarán los problemas que puedan ir surgiendo en el futuro.


Assuntos
Anti-Infecciosos , Animais , Humanos , Anti-Infecciosos/uso terapêutico , Saúde Global , Coleta de Dados
19.
Chem Biodivers ; 20(7): e202300135, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37172262

RESUMO

Gastrointestinal nematode parasitism is a major burden to small ruminant production globally, compounded by increasing anthelmintic resistance. Previous studies have identified essential oils (EOs) from the Lippia genus with antiprotozoal and anthelmintic effects. Lippia dominguensis Moldenke (Ld), an endemic specie from the Dominican Republic, has similar popular uses, however, is chemically and pharmacologically yet uncharacterized. Here, we investigated the in vitro anthelmintic activity of LdEO and its ultrastructural effects on eggs and adult nematodes of Haemonchus contortus multidrug-resistant isolated. The GC/MS analysis showed linalool (33.85 %), 1,8-cineole (30.88 %), and δ-terpineol (10.61 %) as the main EO constituents. The LdEO showed an IC50 =0.523 mg/mL in the egg hatch test, and the motility in the adult worm motility test was 95.8 % at 1 mg/mL. The confocal scanning laser microscopy of eggs indicated permeabilization or disruption of egg cell membranes as the possible mechanism of action of LdEO. The scanning electron microscopy of adult worms showed wrinkling, undulations, and cuticular disruptions. The LdEO displayed significant in vitro anthelmintic activity on eggs and adult worms of H. contortus. Additionally, the LdEO showed low oral toxicity in mice at 2,000 mg/kg. Thus, additional in vivo studies are justified to determine its anthelmintic efficacy in small ruminants.


Assuntos
Anti-Helmínticos , Haemonchus , Lippia , Óleos Voláteis , Animais , Camundongos , Óleos Voláteis/farmacologia , Larva , Anti-Helmínticos/farmacologia , Extratos Vegetais/farmacologia
20.
Sensors (Basel) ; 23(17)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37687792

RESUMO

Green Chemistry is a vital and crucial instrument in achieving pollution control, and it plays an important role in helping society reach the Sustainable Development Goals (SDGs). NIR (near-infrared spectroscopy) has been utilized as an alternate technique for molecular identification, making the process faster and less expensive. Near-infrared diffuse reflectance spectroscopy and Machine Learning (ML) algorithms were utilized in this study to construct identification and classification models of bacteria such as Escherichia coli, Salmonella enteritidis, Enterococcus faecalis and Listeria monocytogenes. Furthermore, divide these bacteria into Gram-negative and Gram-positive groups. The green and quick approach was created by combining NIR spectroscopy with a diffuse reflectance accessory. Using infrared spectral data and ML techniques such as principal component analysis (PCA), hierarchical cluster analysis (HCA) and K-Nearest Neighbor (KNN), It was feasible to accomplish the identification and classification of four bacteria and classify these bacteria into two groups: Gram-positive and Gram-negative, with 100% accuracy. We may conclude that our study has a high potential for bacterial identification and classification, as well as being consistent with global policies of sustainable development and green analytical chemistry.


Assuntos
Algoritmos , Espectroscopia de Luz Próxima ao Infravermelho , Bactérias , Química Analítica , Escherichia coli , Aprendizado de Máquina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA