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1.
Cell ; 151(4): 794-806, 2012 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-23141538

RESUMO

PDI catalyzes the oxidative folding of disulfide-containing proteins. However, the sequence of reactions leading to a natively folded and oxidized protein remains unknown. Here we demonstrate a technique that enables independent measurements of disulfide formation and protein folding. We find that non-native disulfides are formed early in the folding pathway and can trigger misfolding. In contrast, a PDI domain favors native disulfides by catalyzing oxidation at a late stage of folding. We propose a model for cotranslational oxidative folding wherein PDI acts as a placeholder that is relieved by the pairing of cysteines caused by substrate folding. This general mechanism can explain how PDI catalyzes oxidative folding in a variety of structurally unrelated substrates.


Assuntos
Pró-Colágeno-Prolina Dioxigenase/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Dobramento de Proteína , Dissulfetos , Microscopia de Força Atômica , Modelos Moleculares , Oxirredução , Proteínas/química , Proteínas/metabolismo
2.
Genes Dev ; 32(13-14): 965-977, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29954833

RESUMO

R loops are an important source of genome instability, largely due to their negative impact on replication progression. Yra1/ALY is an abundant RNA-binding factor conserved from yeast to humans and required for mRNA export, but its excess causes lethality and genome instability. Here, we show that, in addition to ssDNA and ssRNA, Yra1 binds RNA-DNA hybrids in vitro and, when artificially overexpressed, can be recruited to chromatin in an RNA-DNA hybrid-dependent manner, stabilizing R loops and converting them into replication obstacles in vivo. Importantly, an excess of Yra1 increases R-loop-mediated genome instability caused by transcription-replication collisions regardless of whether they are codirectional or head-on. It also induces telomere shortening in telomerase-negative cells and accelerates senescence, consistent with a defect in telomere replication. Our results indicate that RNA-DNA hybrids form transiently in cells regardless of replication and, after stabilization by excess Yra1, compromise genome integrity, in agreement with a two-step model of R-loop-mediated genome instability. This work opens new perspectives to understand transcription-associated genome instability in repair-deficient cells, including tumoral cells.


Assuntos
Instabilidade Cromossômica/genética , Replicação do DNA , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Telômero/genética , Transcrição Gênica , Cromatina/metabolismo , Hibridização de Ácido Nucleico , Ligação Proteica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Telômero/metabolismo
3.
Brief Bioinform ; 24(4)2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37406192

RESUMO

Recent advances in long read technologies not only enable large consortia to aim to sequence all eukaryotes on Earth, but they also allow individual laboratories to sequence their species of interest with relatively low investment. Long read technologies embody the promise of overcoming scaffolding problems associated with repeats and low complexity sequences, but the number of contigs often far exceeds the number of chromosomes and they may contain many insertion and deletion errors around homopolymer tracts. To overcome these issues, we have implemented the ILRA pipeline to correct long read-based assemblies. Contigs are first reordered, renamed, merged, circularized, or filtered if erroneous or contaminated. Illumina short reads are used subsequently to correct homopolymer errors. We successfully tested our approach by improving the genome sequences of Homo sapiens, Trypanosoma brucei, and Leptosphaeria spp., and by generating four novel Plasmodium falciparum assemblies from field samples. We found that correcting homopolymer tracts reduced the number of genes incorrectly annotated as pseudogenes, but an iterative approach seems to be required to correct more sequencing errors. In summary, we describe and benchmark the performance of our new tool, which improved the quality of novel long read assemblies up to 1 Gbp. The pipeline is available at GitHub: https://github.com/ThomasDOtto/ILRA.


Assuntos
Genoma , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Análise de Sequência de DNA , Pseudogenes , Cromossomos
4.
Mol Biol Evol ; 40(6)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37235753

RESUMO

Enzymes catalyze the chemical reactions of life. For nearly half of known enzymes, catalysis requires the binding of small molecules known as cofactors. Polypeptide-cofactor complexes likely formed at a primordial stage and became starting points for the evolution of many efficient enzymes. Yet, evolution has no foresight so the driver for the primordial complex formation is unknown. Here, we use a resurrected ancestral TIM-barrel protein to identify one potential driver. Heme binding at a flexible region of the ancestral structure yields a peroxidation catalyst with enhanced efficiency when compared to free heme. This enhancement, however, does not arise from protein-mediated promotion of catalysis. Rather, it reflects the protection of bound heme from common degradation processes and a resulting longer lifetime and higher effective concentration for the catalyst. Protection of catalytic cofactors by polypeptides emerges as a general mechanism to enhance catalysis and may have plausibly benefited primordial polypeptide-cofactor associations.


Assuntos
Heme , Peptídeos , Catálise
5.
Mol Biol Evol ; 40(3)2023 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-36788592

RESUMO

Many metabolites are generated in one step of a biochemical pathway and consumed in a subsequent step. Such metabolic intermediates are often reactive molecules which, if allowed to freely diffuse in the intracellular milieu, could lead to undesirable side reactions and even become toxic to the cell. Therefore, metabolic intermediates are often protected as protein-bound species and directly transferred between enzyme active sites in multi-functional enzymes, multi-enzyme complexes, and metabolons. Sequestration of reactive metabolic intermediates thus contributes to metabolic efficiency. It is not known, however, whether this evolutionary adaptation can be relaxed in response to challenges to organismal survival. Here, we report evolutionary repair experiments on Escherichia coli cells in which an enzyme crucial for the biosynthesis of proline has been deleted. The deletion makes cells unable to grow in a culture medium lacking proline. Remarkably, however, cell growth is efficiently restored by many single mutations (12 at least) in the gene of glutamine synthetase. The mutations cause the leakage to the intracellular milieu of a highly reactive phosphorylated intermediate common to the biosynthetic pathways of glutamine and proline. This intermediate is generally assumed to exist only as a protein-bound species. Nevertheless, its diffusion upon mutation-induced leakage enables a new route to proline biosynthesis. Our results support that leakage of sequestered metabolic intermediates can readily occur and contribute to organismal adaptation in some scenarios. Enhanced availability of reactive molecules may enable the generation of new biochemical pathways and the potential of mutation-induced leakage in metabolic engineering is noted.


Assuntos
Evolução Biológica , Vias Biossintéticas , Sobrevivência Celular , Mutação , Prolina
6.
J Virol ; 97(1): e0177322, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36475764

RESUMO

Flaviviruses have a cytoplasmic replicative cycle, and crucial events, such as genome translation and replication, occur in the endoplasmic reticulum. However, some viral proteins, such as C, NS1, and NS5 from Zika virus (ZIKV) containing nuclear localization signals (NLSs) and nuclear export signals (NESs), are also located in the nucleus of Vero cells. The NS2A, NS3, and NS4A proteins from dengue virus (DENV) have also been reported to be in the nucleus of A549 cells, and our group recently reported that the NS3 protein is also located in the nucleus of Huh7 and C636 cells during DENV infection. However, the NS3 protease-helicase from ZIKV locates in the perinuclear region of infected cells and alters the morphology of the nuclear lamina, a component of the nuclear envelope. Furthermore, ZIKV NS3 has been reported to accumulate on the concave face of altered kidney-shaped nuclei and may be responsible for modifying other elements of the nuclear envelope. However, nuclear localization of NS3 from ZIKV has not been substantially investigated in human host cells. Our group has recently reported that DENV and ZIKV NS3 alter the nuclear pore complex (NPC) by cleaving some nucleoporins. Here, we demonstrate the presence of ZIKV NS3 in the nucleus of Huh7 cells early in infection and in the cytoplasm at later times postinfection. In addition, we found that ZIKV NS3 contains an NLS and a putative NES and uses the classic import (importin-α/ß) and export pathway via CRM-1 to be transported between the cytoplasm and the nucleus. IMPORTANCE Flaviviruses have a cytoplasmic replication cycle, but recent evidence indicates that nuclear elements play a role in their viral replication. Viral proteins, such as NS5 and C, are imported into the nucleus, and blocking their import prevents replication. Because of the importance of the nucleus in viral replication and the role of NS3 in the modification of nuclear components, we investigated whether NS3 can be localized in the nucleus during ZIKV infection. We found that NS3 is imported into the nucleus via the importin pathway and exported to the cytoplasm via CRM-1. The significance of viral protein nuclear import and export and its relationship with infection establishment is highlighted, emphasizing the development of new host-directed antiviral therapeutic strategies.


Assuntos
Transporte Ativo do Núcleo Celular , Carioferinas , Proteínas não Estruturais Virais , Zika virus , Animais , Humanos , alfa Carioferinas/metabolismo , beta Carioferinas/metabolismo , Chlorocebus aethiops , Carioferinas/metabolismo , Sinais de Localização Nuclear/metabolismo , Células Vero , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Zika virus/genética , Infecção por Zika virus , Vírus da Dengue
7.
New Phytol ; 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39187985

RESUMO

Population genetics theory predicts a relationship between fitness, genetic diversity (H0) and effective population size (Ne), which is often tested through heterozygosity-fitness correlations (HFCs). We tested whether population and individual fertility and heterozygosity are correlated in two endangered Mexican spruces (Picea martinezii and Picea mexicana) by combining genomic, demographic and reproductive data (seed development and germination traits). For both species, there was a positive correlation between population size and seed development traits, but not germination rate. Individual genome-wide heterozygosity and seed traits were only correlated in P. martinezii (general-effects HFC), and none of the candidate single nucleotide polymorphisms (SNPs) associated with individual fertility showed heterozygote advantage in any species (no local-effects HFC). We observed a single and recent (c. 30 thousand years ago (ka)) population decline for P. martinezii; the collapse of P. mexicana occurred in two phases separated by a long period of stability (c. 800 ka). Recruitment always contributed more to total population census than adult trees in P. mexicana, while this was only the case in the largest populations of P. martinezii. Equating fitness to either H0 or Ne, as traditionally proposed in conservation biology, might not always be adequate, as species-specific evolutionary factors can decouple the expected correlation between these parameters.

8.
New Phytol ; 241(3): 984-999, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38098153

RESUMO

Plant hydraulics is crucial for assessing the plants' capacity to extract and transport water from the soil up to their aerial organs. Along with their capacity to exchange water between plant compartments and regulate evaporation, hydraulic properties determine plant water relations, water status and susceptibility to pathogen attacks. Consequently, any variation in the hydraulic characteristics of plants is likely to significantly impact various mechanisms and processes related to plant growth, survival and production, as well as the risk of biotic attacks and forest fire behaviour. However, the integration of hydraulic traits into disciplines such as plant pathology, entomology, fire ecology or agriculture can be significantly improved. This review examines how plant hydraulics can provide new insights into our understanding of these processes, including modelling processes of vegetation dynamics, illuminating numerous perspectives for assessing the consequences of climate change on forest and agronomic systems, and addressing unanswered questions across multiple areas of knowledge.


Assuntos
Mudança Climática , Ecossistema , Água/fisiologia , Solo , Produtos Agrícolas , Secas
9.
Plant Cell Environ ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39077899

RESUMO

Hydraulic failure due to xylem embolism has been identified as one of the main mechanisms involved in drought-induced forest decline. Trees vulnerability to hydraulic failure depends on their hydraulic safety margin (HSM). While it has been shown that HSM globally converges between tree species and biomes, there is still limited knowledge regarding how HSM can adjust locally to varying drought conditions within species. In this study, we relied on three long-term partial rainfall exclusion experiments to investigate the plasticity of hydraulic traits and HSM for three Mediterranean tree species (Quercus ilex L., Quercus pubescens Willd., and Pinus halepensis Mill.). For all species, a homeostasis of HSM in response to rainfall reduction was found, achieved through different mechanisms. For Q. ilex, the convergence in HSM is attributed to the adjustment of both the turgor loss point (Ψtlp) and the water potential at which 50% of xylem conductivity is lost due to embolism (P50). In contrast, the maintenance of HSM for P. halepensis and Q. pubescens is related to its isohydric behavior for the first and leaf area adjustment for the latter. It remains to be seen whether this HSM homeostasis can be generalized and if it will be sufficient to withstand extreme droughts expected in the Mediterranean region.

10.
Blood ; 139(8): 1208-1221, 2022 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-34482403

RESUMO

Inherited predisposition to myeloid malignancies is more common than previously appreciated. We analyzed the whole-exome sequencing data of paired leukemia and skin biopsy samples from 391 adult patients from the Beat AML 1.0 consortium. Using the 2015 American College of Medical Genetics and Genomics (ACMG) guidelines for variant interpretation, we curated 1547 unique variants from 228 genes. The pathogenic/likely pathogenic (P/LP) germline variants were identified in 53 acute myeloid leukemia (AML) patients (13.6%) in 34 genes, including 6.39% (25/391) of patients harboring P/LP variants in genes considered clinically actionable (tier 1). 41.5% of the 53 patients with P/LP variants were in genes associated with the DNA damage response. The most frequently mutated genes were CHEK2 (8 patients) and DDX41 (7 patients). Pathogenic germline variants were also found in new candidate genes (DNAH5, DNAH9, DNMT3A, and SUZ12). No strong correlation was found between the germline mutational rate and age of AML onset. Among 49 patients who have a reported history of at least one family member affected with hematological malignancies, 6 patients harbored known P/LP germline variants and the remaining patients had at least one variant of uncertain significance, suggesting a need for further functional validation studies. Using CHEK2 as an example, we show that three-dimensional protein modeling can be one of the effective methodologies to prioritize variants of unknown significance for functional studies. Further, we evaluated an in silico approach that applies ACMG curation in an automated manner using the tool for assessment and (TAPES) prioritization in exome studies, which can minimize manual curation time for variants. Overall, our findings suggest a need to comprehensively understand the predisposition potential of many germline variants in order to enable closer monitoring for disease management and treatment interventions for affected patients and families.


Assuntos
Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Leucemia Mieloide Aguda/genética , Proteínas de Neoplasias/genética , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
Glob Chang Biol ; 30(9): e17503, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39315483

RESUMO

Increasing tree diversity is considered a key management option to adapt forests to climate change. However, the effect of species diversity on a forest's ability to cope with extreme drought remains elusive. In this study, we assessed drought tolerance (xylem vulnerability to cavitation) and water stress (water potential), and combined them into a metric of drought-mortality risk (hydraulic safety margin) during extreme 2021 or 2022 summer droughts in five European tree diversity experiments encompassing different biomes. Overall, we found that drought-mortality risk was primarily driven by species identity (56.7% of the total variability), while tree diversity had a much lower effect (8% of the total variability). This result remained valid at the local scale (i.e within experiment) and across the studied European biomes. Tree diversity effect on drought-mortality risk was mediated by changes in water stress intensity, not by changes in xylem vulnerability to cavitation. Significant diversity effects were observed in all experiments, but those effects often varied from positive to negative across mixtures for a given species. Indeed, we found that the composition of the mixtures (i.e., the identities of the species mixed), but not the species richness of the mixture per se, is a driver of tree drought-mortality risk. This calls for a better understanding of the underlying mechanisms before tree diversity can be considered an operational adaption tool to extreme drought. Forest diversification should be considered jointly with management strategies focussed on favouring drought-tolerant species.


Assuntos
Biodiversidade , Secas , Florestas , Árvores , Árvores/fisiologia , Europa (Continente) , Mudança Climática , Xilema/fisiologia
12.
Horm Metab Res ; 56(2): 118-127, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38081188

RESUMO

Pituitary adenomas are benign tumors of the anterior portion of the pituitary gland (adenohypophysis), representing the 25% of all the tumor alterations. Pituitary adenomas are classified by the type of hormone secreted, cellularity, size, and structural alterations by the hormonal segregation. The diagnosis consists on the histopathological identification of cell types and the image-guided by magnetic resonance or tomography; the treatment can be both pharmacological and surgical. Metabolic Syndrome is the set of clinical conditions that increase the risk of cardiovascular diseases with an estimated prevalence of 25% worldwide. The alterations of metabolic syndrome are obesity, hypertension, dyslipidemia, insulin resistance, and diabetes mellitus type II. Pituitary adenomas and metabolic syndrome have an important relationship, hormone-secreting by pituitary adenomas affects a myriad of signaling pathways, which allows a favorable environment for the appearance of the metabolic syndrome. Moreover, patients with pituitary adenomas are shown to have an improvement in metabolic parameters after the medical/surgical treatment. The objective of this review is to explore the possible mechanisms through which PAs contributes to MetSx.


Assuntos
Adenoma , Síndrome Metabólica , Neoplasias Hipofisárias , Humanos , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/terapia , Neoplasias Hipofisárias/diagnóstico , Síndrome Metabólica/complicações , Adenoma/complicações , Adenoma/terapia , Adenoma/diagnóstico , Hipófise/patologia , Hormônios
13.
Inorg Chem ; 63(23): 10500-10510, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38805658

RESUMO

The direct conversion of solar energy into chemical energy represents an enormous challenge for current science. One of the commonly proposed photocatalytic systems is composed of a photosensitizer (PS) and a catalyst, together with a sacrificial electron donor (ED) when only the reduction of protons to H2 is addressed. Layered double hydroxides (LDH) have emerged as effective catalysts. Herein, two Co-Al LDH and their composites with graphene oxide (GO) or graphene quantum dots (GQD) have been prepared by coprecipitation and urea hydrolysis, which determined their structure and so their catalytic performance, giving H2 productions between 1409 and 8643 µmol g-1 using a ruthenium complex as PS and triethanolamine as ED at 450 nm. The influence of different factors, including the integration of both components, on their catalytic behavior, has been studied. The proper arrangement between the particles of both components seems to be the determining factor for achieving a synergistic interaction between LDH and GO or GQD. The novel Co-Al LDH composite with intercalated GQD achieved an outstanding catalytic efficiency (8643 µmol H2 g-1) and exhibited excellent reusability after 3 reaction cycles, thus representing an optimal integration between graphene materials and Co-Al LDH for visible light driven H2 photocatalytic production.

14.
Inorg Chem ; 63(14): 6202-6216, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38385171

RESUMO

Ruthenium(II) complexes containing diimine ligands have contributed to the development of agents for photoactivated chemotherapy. Several approaches have been used to obtain photolabile Ru(II) complexes. The two most explored have been the use of monodentate ligands and the incorporation of steric effects between the bidentate ligands and the Ru(II). However, the introduction of electronic effects in the ligands has been less explored. Herein, we report a systematic experimental, theoretical, and photocytotoxicity study of a novel series of Ru(II) complexes Ru1-Ru5 of general formula [Ru(phen)2(N∧N')]2+, where N∧N' are different minimal strained ligands based on the 1-aryl-4-benzothiazolyl-1,2,3-triazole (BTAT) scaffold, being CH3 (Ru1), F (Ru2), CF3 (Ru3), NO2 (Ru4), and N(CH3)2 (Ru5) substituents in the R4 of the phenyl ring. The complexes are stable in solution in the dark, but upon irradiation in water with blue light (λex = 465 nm, 4 mW/cm2) photoejection of the ligand BTAT was observed by HPLC-MS spectrometry and UV-vis spectroscopy, with t1/2 ranging from 4.5 to 14.15 min depending of the electronic properties of the corresponding BTAT, being Ru4 the less photolabile (the one containing the more electron withdrawing substituent, NO2). The properties of the ground state singlet and excited state triplet of Ru1-Ru5 have been explored using density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. A mechanism for the photoejection of the BTAT ligand from the Ru complexes, in H2O, is proposed. Phototoxicity studies in A375 and HeLa human cancer cell lines showed that the new Ru BTAT complexes were strongly phototoxic. An enhancement of the emission intensity of HeLa cells treated with Ru5 was observed in response to increasing doses of light due to the photoejection of the BTAT ligand. These studies suggest that BTAT could serve as a photocleavable protecting group for the cytotoxic bis-aqua ruthenium warhead [Ru(phen)2(OH2)2]2+.


Assuntos
Neoplasias , Rutênio , Humanos , Quelantes , Rutênio/farmacologia , Rutênio/química , Ligantes , Células HeLa , Dióxido de Nitrogênio
15.
Clin Chem Lab Med ; 62(8): 1538-1547, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-38581294

RESUMO

AIM: Blood Sampling Guidelines have been developed to target European emergency medicine-related professionals involved in the blood sampling process (e.g. physicians, nurses, phlebotomists working in the ED), as well as laboratory physicians and other related professionals. The guidelines population focus on adult patients. The development of these blood sampling guidelines for the ED setting is based on the collaboration of three European scientific societies that have a role to play in the preanalytical phase process: EuSEN, EFLM, and EUSEM. The elaboration of the questions was done using the PICO procedure, literature search and appraisal was based on the GRADE methodology. The final recommendations were reviewed by an international multidisciplinary external review group. RESULTS: The document includes the elaborated recommendations for the selected sixteen questions. Three in pre-sampling, eight regarding sampling, three post-sampling, and two focus on quality assurance. In general, the quality of the evidence is very low, and the strength of the recommendation in all the questions has been rated as weak. The working group in four questions elaborate the recommendations, based mainly on group experience, rating as good practice. CONCLUSIONS: The multidisciplinary working group was considered one of the major contributors to this guideline. The lack of quality information highlights the need for research in this area of the patient care process. The peculiarities of the emergency medical areas need specific considerations to minimise the possibility of errors in the preanalytical phase.


Assuntos
Coleta de Amostras Sanguíneas , Serviço Hospitalar de Emergência , Humanos , Coleta de Amostras Sanguíneas/normas , Coleta de Amostras Sanguíneas/métodos , Medicina de Emergência/normas , Fase Pré-Analítica/normas , Europa (Continente) , Sociedades Médicas , Química Clínica/normas , Química Clínica/métodos
16.
Clin Exp Dermatol ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39047067

RESUMO

INTRODUCTION: Mucocutaneous Behcet's disease is often a therapeutic challenge. Roflumilast has shown promise in other inflammatory dermatological conditions. The objective of this study is to evaluate the characteristics, effectiveness and safety of roflumilast in the treatment of Behçet's Disease-associated aphthosis in routine clinical practice. METHODS: Single cohort ambispective observational study. 11 patients with Behçet disease treated with roflumilast participated. Data collection included demographic, clinical and outcome variables. Statistical analysis compared 12 weeks of treatment with roflumilast with a previous period without treatment and with a period with the previous treatment. RESULTS: During treatment with roflumilast, a reduction in flare-ups and oral ulcers was observed compared to the untreated period and the previous treatment period. A reduction in genital ulcers, pain and ulcer duration was observed between the Whitout treatment period and the Roflumilast treatment period.Adverse effects occurred in 54% of patients, most of which were self-limiting or manageable with dose adjustment. No patient withdrew treatment. DISCUSSION: Roflumilast appears a promising option in the treatment of Behçet's disease with favourable effectiveness, safety and tolerability profiles. Although further research is needed, roflumilast offers a promising treatment option for Behçet's Disease-associated aphthosis, which could improve patients' quality of life and address unmet therapeutic needs.

17.
Mar Drugs ; 22(8)2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39195485

RESUMO

Dengue, caused by the dengue virus (DENV), is a global health threat transmitted by Aedes mosquitoes, resulting in 400 million cases annually. The disease ranges from mild to severe, with potential progression to hemorrhagic dengue. Current research is focused on natural antivirals due to challenges in vector control. This study evaluates the antiviral potential of peptides derived from the microalgae Phaeodactylum tricornutum, known for its bioactive compounds. Microalgae were cultivated under controlled conditions, followed by protein extraction and hydrolysis to produce four peptide fractions. These fractions were assessed for cytotoxicity via the MTT assay and antiviral activity against DENV serotype 2 using flow cytometry and plaque formation assays. The 10-30 kDa peptide fraction, at 150 and 300 µg/mL concentrations, demonstrated no cytotoxicity and significantly reduced the percentage of infected cells and viral titers. These findings suggest that peptides derived from Phaeodactylum tricornutum exhibit promising antiviral activity against dengue virus serotype 2, potentially contributing to developing new therapeutic approaches for dengue.


Assuntos
Antivirais , Vírus da Dengue , Microalgas , Vírus da Dengue/efeitos dos fármacos , Antivirais/farmacologia , Antivirais/química , Animais , Hidrolisados de Proteína/farmacologia , Hidrolisados de Proteína/química , Dengue/tratamento farmacológico , Dengue/virologia , Peptídeos/farmacologia , Peptídeos/química , Sorogrupo , Chlorocebus aethiops , Humanos , Aedes/efeitos dos fármacos , Células Vero
18.
Acta Neurochir (Wien) ; 166(1): 219, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38758379

RESUMO

PURPOSE: The dentate nucleus (DN) is the largest, most lateral, and phylogenetically most recent of the deep cerebellar nuclei. Its pivotal role encompasses the planning, initiation, and modification of voluntary movement but also spans non-motor functions like executive functioning, visuospatial processing, and linguistic abilities. This review aims to offer a comprehensive description of the DN, detailing its embryology, anatomy, physiology, and clinical relevance, alongside an analysis of dentatotomy. METHODS AND RESULTS: We delve into the history, embryology, anatomy, vascular supply, imaging characteristics, and clinical significance of the DN. Furthermore, we thoroughly review the dentatotomy, emphasizing its role in treating spasticity. CONCLUSIONS: Understanding the intricacies of the anatomy, physiology, vasculature, and projections of the DN has taken on increased importance in current neurosurgical practice. Advances in technology have unveiled previously unknown functions of the deep cerebellar nuclei, predominantly related to non-motor domains. Such discoveries are revitalizing older techniques, like dentatotomy, and applying them to newer, more localized targets.


Assuntos
Núcleos Cerebelares , Humanos , Núcleos Cerebelares/cirurgia , Núcleos Cerebelares/anatomia & histologia , Procedimentos Neurocirúrgicos/métodos , Espasticidade Muscular/cirurgia
19.
Plant Dis ; 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38268178

RESUMO

Roselle (Hibiscus sabdariffa L.) is a crop of economic importance, refreshing drinks are prepared from its calyces, it is also attributed to antioxidant, antibacterial, and antihypertensive properties (Da-Costa-Rocha et al. 2014). In November 2022, in municipality of Iguala (18.355592N, 99.548546W, 749 m above sea level), Guerrero, México, roselle plants of approximately 1.5 months of age with basal rot were detected under greenhouse conditions. The symptoms consisted of wilting, yellowing, and root and stem rot with constriction in the base of the stem. The symptoms were detected in approximately 15% of plants at the operation. From symptomatic tissue, cuts were made into approximately 0.5 cm pieces, sterilized with 2% NaClO, washed with sterile distilled water, transferred to PDA medium amended with 50 mg/liter of Chloramphenicol, and incubated in the dark for four days at 28 °C. Rhizoctonia-like colonies were consistently obtained, and nine isolates were selected and purified by the hyphal-tip method. After four days, isolates developed a mycelium was light-white that became brown with age. Right-angled hyphal branching was also observed, in addition to a slight constriction at the base of the branches. In some older cultures, numerous dark brown sclerotia were observed. They were multinucleate cell with three to eight nuclei and measured from 1 to 2 mm in diameter. Together these characteristics were consistent with the description of Rhizoctonia solani Kühn (Parmeter 1970). The anastomosis group (AG) was confirmed by amplifying the ITS region with the primers ITS1 and ITS4 (White et al. 1990) of the RIJAM3 and RIJAM5 strains. The sequences were deposited in GenBank (Nos. OR364496 and OR364497 for RIJAM3 and RIJAM5, respectively). BLAST analysis, both isolates indicated 99.7 identity to R. solani AG-4 HG-I (GenBank: KM013470) strain ICMP 20043 (Ireland et al. 2015). The phylogenetic analysis of AGs sequences allowed assignment of isolates RIJAM3 and RIJAM5 to the AG-4 HG-1 clade. A pathogenicity test was performed on 20 one-month-old roselle plants. Mycelium of RIJAM3 isolate was inserted into the base of the stem with a sterile toothpick. As a control, a sterile toothpick with no mycelium was inserted in ten healthy plants. Additionally, 50 eight-day-old seedlings were inoculated by placing a 5-mm diameter agar plug colonized with mycelium of RIJAM3 at the base of the stem 10 mm below the soil surface. As control treatments, uncolonized PDA plugs were deposited at the base of 25 seedlings. The inoculated plants were incubated in a greenhouse with an average temperature and relative humidity of 28°C and 85%, respectively. Following inoculation, symptoms similar to those observed in the original outbreak were observed in plants after six days and only after four days in seedlings. In both experiments, the control plants and seedlings remained asymptomatic. R. solani was re-isolated from plants and seedlings, complying with Koch's postulates. The pathogenicity testing was repeated twice, with concordant results. In Nigeria and Malaysia R. solani was reported to seedling death to cause seedling dieback in roselle (Adeniji 1970; Eslaminejad and Zakaria 2011). In México R. solani AG-4 has been previously reported in crops of potato, chili and tomato (Montero-Tavera et al. 2013; Ortega-Acosta et al. 2022; Virgen-Calleros et al. 2000). To the best of our knowledge, this is the first report of R. solani AG-4 HG-I as a causing of root and basal stem rot on roselle in Mexico. This research provides information essential for informing the management of this disease, and may help design measures to prevent the spread of the pathogen to other regions.

20.
J Pediatr Nurs ; 75: 164-172, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38160469

RESUMO

PURPOSE: To evaluate the self-reported perspectives of participants involved in the Previene Cádiz intervention for preventing pediatric overweight and obesity. DESIGN AND METHODS: This qualitative study collected information through the World Café technique. A purposive sample of 40 participants was used, of which 14 were schoolchildren, 12 were teachers, and 14 were parent volunteers. The data were segmented, and concepts were created and grouped into dimensions and categories. RESULTS: The participants confirmed they had learned new information and behaviors about healthy habits. Parental awareness was considered a crucial and necessary element in changing family habits; therefore, increasing the motivation of family members was deemed a critical task in public health interventions conducted in school settings. DISCUSSION: Despite the suitability of qualitative methodology to evaluate the perceptions of the main players in an educational intervention, scientific literature is scarce. Obtaining information from the educational community about an intervention is not always easy, so the perspectives of teachers, students, and families about the Previene Cádiz intervention through the World Café approach is considered a relevant contribution. CONCLUSIONS: The participants considered the intervention positive in terms of learning and fostering increased knowledge, awareness, and healthy behaviors. PRACTICE IMPLICATIONS: Future interventions should encourage the active participation of all social groups involved, integrating dynamic and collaborative training activities that are acceptable to all participants.


Assuntos
Sobrepeso , Obesidade Infantil , Criança , Humanos , Sobrepeso/prevenção & controle , Obesidade/prevenção & controle , Comportamentos Relacionados com a Saúde , Família , Pesquisa Qualitativa , Obesidade Infantil/prevenção & controle
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