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1.
Diagnostics (Basel) ; 14(16)2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39202282

RESUMO

Immune checkpoint inhibitors (ICIs) have significantly transformed cancer treatment, but their use is linked to immune-related adverse events (irAEs), including the rare ICI-associated myocarditis, myositis, and myasthenia gravis (MMM) overlap syndrome. This systematic review aims to highlight MMM's clinical implications in emergency departments. PubMed and Embase were searched using a specific search strategy. Reports were eligible for inclusion if all three conditions were present and associated with the use of an ICI. Data were extracted by independent reviewers using the Rayyan web application for systematic reviews. Descriptive statistics and qualitative synthesis were used to summarize demographic, clinical, and treatment data for the reported cases. Among 50 cases, predominantly associated with melanoma, lung cancer, and renal cancer, the in-hospital mortality rate was 38.0%. The most commonly presenting symptoms were ptosis (58%), dyspnea (48%), diplopia (42%), or myalgia (36%). The median time from ICI initiation to MMM presentation was 21 days (interquartile range: 15-28 days). Corticosteroids were the primary treatment for the irAEs. MMM, a rare but potentially fatal complication of ICI therapy, requires prompt recognition in emergency settings. Corticosteroids should be initiated if suspected, without waiting for confirmation. Multidisciplinary collaboration is vital for diagnosis and treatment planning. Research on MMM's link to specific cancers and ICIs is imperative for better risk assessment and interventions.

2.
bioRxiv ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-39026723

RESUMO

F luorogenic ap tamers (FAPs) have become an increasingly important tool in cellular sensing and pathogen diagnostics. However, fine-tuning FAPs for enhanced performance remains challenging even with the structural details provided by X-ray crystallography. Here we present a novel approach to optimize a DNA-based FAP (D-FAP), Lettuce, on repurposed Illumina next-generation sequencing (NGS) chips. When substituting its cognate chromophore, DFHBI-1T, with TO1-biotin, Lettuce not only shows a red-shifted emission peak by 53 nm (from 505 to 558 nm), but also a 4-fold bulk fluorescence enhancement. After screening 8,821 Lettuce variants complexed with TO1-biotin, the C14T mutation is found to exhibit an improved apparent dissociated constant ( vs. 0.82 µM), an increased quantum yield (QY: 0.62 vs. 0.59) and an elongated fluorescence lifetime (τ: 6.00 vs. 5.77 ns), giving 45% more ensemble fluorescence than the canonical Lettuce/TO1-biotin complex. Molecular dynamic simulations further indicate that the π-π stacking interaction is key to determining the coordination structure of TO1-biotin in Lettuce. Our screening-and-simulation pipeline can effectively optimize FAPs without any prior structural knowledge of the canonical FAP/chromophore complexes, providing not only improved molecular probes for fluorescence sensing but also insights into aptamer-chromophore interactions.

3.
Adv Mater ; 34(41): e2204957, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35945159

RESUMO

NanoCluster Beacons (NCBs) are multicolor silver nanocluster probes whose fluorescence can be activated or tuned by a proximal DNA strand called the activator. While a single-nucleotide difference in a pair of activators can lead to drastically different activation outcomes, termed polar opposite twins (POTs), it is difficult to discover new POT-NCBs using the conventional low-throughput characterization approaches. Here, a high-throughput selection method is reported that takes advantage of repurposed next-generation-sequencing chips to screen the activation fluorescence of ≈40 000 activator sequences. It is found that the nucleobases at positions 7-12 of the 18-nucleotide-long activator are critical to creating bright NCBs and positions 4-6 and 2-4 are hotspots to generate yellow-orange and red POTs, respectively. Based on these findings, a "zipper-bag" model is proposed that can explain how these hotspots facilitate the formation of distinct silver cluster chromophores and alter their chemical yields. Combining high-throughput screening with machine-learning algorithms, a pipeline is established to design bright and multicolor NCBs in silico.


Assuntos
Nanopartículas Metálicas , Prata , DNA/química , Nanopartículas Metálicas/química , Nucleotídeos , Prata/química , Espectrometria de Fluorescência
4.
Food Microbiol ; 70: 262-268, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29173635

RESUMO

Vacuolar acidification serves as a homeostatic mechanism to regulate intracellular pH, ion and chemical balance, as well as trafficking and recycling of proteins and nutrients, critical for normal cellular function. This study reports on the importance of vacuole acidification during wine-like fermentation. Ninety-three mutants (homozygous deletions in lab yeast strain, BY4743), which result in protracted fermentation when grown in a chemically defined grape juice with 200 g L-1 sugar (pH 3.5), were examined to determine whether fermentation protraction was in part due to a dysfunction in vacuolar acidification (VA) during the early stages of fermentation, and whether VA was responsive to the initial sugar concentration in the medium. Cells after 24 h growth were dual-labelled with propidium iodide and vacuolar specific probe 6-carboxyfluorescein diacetate (6-CFDA) and examined with a FACS analyser for viability and impaired VA, respectively. Twenty mutants showed a greater than two-fold increase in fluorescence intensity; the experimental indicator for vacuolar dysfunction; 10 of which have not been previously annotated to this process. With the exception of Δhog1, Δpbs2 and Δvph1 mutants, where dysfunction was directly related to osmolality; the remainder exhibited increased CF-fluorescence, independent of sugar concentration at 20 g L-1 or 200 g L-1. These findings offer insight to the importance of VA to cell growth in high sugar media.


Assuntos
Saccharomyces cerevisiae/metabolismo , Açúcares/metabolismo , Vacúolos/química , Ácidos/metabolismo , Fermentação , Homeostase , Concentração de Íons de Hidrogênio , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Vacúolos/metabolismo , Vitis/metabolismo , Vitis/microbiologia
5.
J Am Chem Soc ; 139(29): 10126-10132, 2017 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-28658952

RESUMO

This paper describes the role of tetraalkylammonium counterions [NR4+, R = -CH3, -CH2CH3, -(CH2)2CH3, or -(CH2)3CH3] in gating the electrostatic potential at the interface between the 6-mercaptohexanoate (MHA) ligand shell of a PbS quantum dot (QD) and water. The permeability of this ligand shell to a negatively charged anthraquinone derivative (AQ), measured from the yield of electron transfer (eT) from the QD core to AQ, increases as the steric bulk of NR4+ increases (for a given concentration of NR4+). This result indicates that bulkier counterions screen repulsive interactions at the ligand/solvent interface more effectively than smaller counterions. Free energy scaling analysis and molecular dynamics simulations suggest that ion pairing between the ligand shell of the QD and NR4+ results from a combination of electrostatic and van der Waals components, and that the van der Waals interaction promotes ion pairing with longer-chain counterions and more effective screening. This work provides molecular-level details that dictate a nanoparticle's electrostatic potential and demonstrates the sensitivity of the yield of photoinduced charge transfer between a QD and a molecular probe to even low-affinity binding events at the QD/solvent interface.

6.
BMC Genomics ; 15: 552, 2014 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-24993029

RESUMO

BACKGROUND: Wine fermentation is a harsh ecological niche to which wine yeast are well adapted. The initial high osmotic pressure and acidity of grape juice is followed by nutrient depletion and increasing concentrations of ethanol as the fermentation progresses. Yeast's adaptation to these and many other environmental stresses, enables successful completion of high-sugar fermentations. Earlier transcriptomic and growth studies have tentatively identified genes important for high-sugar fermentation. Whilst useful, such studies did not consider extended growth (>5 days) in a temporally dynamic multi-stressor environment such as that found in many industrial fermentation processes. Here, we identify genes whose deletion has minimal or no effect on growth, but results in failure to achieve timely completion of the fermentation of a chemically defined grape juice with 200 g L-1 total sugar. RESULTS: Micro- and laboratory-scale experimental fermentations were conducted to identify 72 clones from ~5,100 homozygous diploid single-gene yeast deletants, which exhibited protracted fermentation in a high-sugar medium. Another 21 clones (related by gene function, but initially eliminated from the screen because of possible growth defects) were also included. Clustering and numerical enrichment of genes annotated to specific Gene Ontology (GO) terms highlighted the vacuole's role in ion homeostasis and pH regulation, through vacuole acidification. CONCLUSION: We have identified 93 genes whose deletion resulted in the duration of fermentation being at least 20% longer than the wild type. An extreme phenotype, 'stuck' fermentation, was also observed when DOA4, NPT1, PLC1, PTK2, SIN3, SSQ1, TPS1, TPS2 or ZAP1 were deleted. These 93 Fermentation Essential Genes (FEG) are required to complete an extended high-sugar (wine-like) fermentation. Their importance is highlighted in our Fermentation Relevant Yeast Genes (FRYG) database, generated from literature and the fermentation-relevant phenotypic characteristics of null mutants described in the Saccharomyces Genome Database. The 93-gene set is collectively referred to as the 'Fermentome'. The fact that 10 genes highlighted in this study have not previously been linked to fermentation-related stresses, supports our experimental rationale. These findings, together with investigations of the genetic diversity of industrial strains, are crucial for understanding the mechanisms behind yeast's response and adaptation to stresses imposed during high-sugar fermentations.


Assuntos
Fermentação/genética , Saccharomyces cerevisiae/genética , Transcriptoma , Deleção de Genes , Genes Fúngicos , Engenharia Genética , Concentração de Íons de Hidrogênio , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Vinho/microbiologia
7.
Pancreatology ; 13(5): 508-16, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24075516

RESUMO

INTRODUCTION: More effective therapies are required to improve survival of pancreatic cancer. Possible immunologic targets include tumour associated macrophages (TAMs), generally consisting of M1- and M2-macrophages. We have analysed the impact of TAMS on pancreatic cancer in a syngeneic orthotopic murine model. METHODS: 6606PDA murine pancreatic cancer cells were orthotopically injected into C57BL6 mice. Tumour growth was monitored using MRI. Macrophages were depleted by clodronate liposomes. Tumours including microvessel density were evaluated using immunohistochemistry, immunofluorescence and/or cytometric beads assays. Naïve macrophages were generated employing peritoneal macrophages. In vitro experiments included culturing of macrophages in tumour supernatants as well as tumour cells cultured in macrophage supernatants using arginase as well as Griess assays. RESULTS: Clodronate treatment depleted macrophages by 80% in livers (p = 0.0051) and by 60% in pancreatic tumours (p = 0.0169). MRI revealed tumour growth inhibition from 221.8 mm(3) to 92.3 mm(3) (p = 0.0216). Micro vessel densities were decreased by 44% (p = 0.0315). Yet, MCP-1-, IL-4- and IL-10-levels within pancreatic tumours were unchanged. 6606PDA culture supernatants led to a shift from naïve macrophages towards an M2-phenotype after a 36 h treatment (p < 0.0001), reducing M1-macrophages at the same time (p < 0.037). In vivo, M2-macrophages represented 85% of all TAMs (p < 0.0001). Finally, culture supernatants of M2-macrophages induced tumour growth in vitro by 63.2% (p = 0.0034). CONCLUSIONS: This quid pro quo of tumour cells and M2-macrophages could serve as a new target for future immunotherapies that interrupt tumour promoting activities of TAMs and change the iNOS-arginase balance towards their tumoricidal capacities.


Assuntos
Macrófagos/imunologia , Neoplasias Pancreáticas/imunologia , Animais , Diferenciação Celular , Linhagem Celular Tumoral , Ácido Clodrônico/administração & dosagem , Meios de Cultura/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Neoplasias Pancreáticas/patologia
8.
Org Lett ; 13(6): 1370-3, 2011 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-21348505

RESUMO

Probing the nucleophilic ring-opening of various bicyclic [2.2.1] hetaryne-furan Diels-Alder adducts revealed that efficient reactivity could be observed with heteroatom nucleophiles by using a cationic Rh(I) complex in combination with a chiral Josiphos-type phosphine ligand. Remarkably, this catalyst system was not impeded by the incorporation of a heteroatom into the substrate. Racemic materials afforded separable mixtures of enantioenriched regioisomers, indicating that strong reagent control is operative.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Ródio/química , Compostos Bicíclicos Heterocíclicos com Pontes/química , Catálise , Técnicas de Química Combinatória , Estrutura Molecular , Estereoisomerismo
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