Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 981
Filtrar
1.
Nature ; 626(7998): 283-287, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38297128

RESUMO

Ultracold polyatomic molecules offer opportunities1 in cold chemistry2,3, precision measurements4 and quantum information processing5,6, because of their rich internal structure. However, their increased complexity compared with diatomic molecules presents a challenge in using conventional cooling techniques. Here we demonstrate an approach to create weakly bound ultracold polyatomic molecules by electroassociation7 (F.D. et al., manuscript in preparation) in a degenerate Fermi gas of microwave-dressed polar molecules through a field-linked resonance8-11. Starting from ground-state NaK molecules, we create around 1.1 × 103 weakly bound tetratomic (NaK)2 molecules, with a phase space density of 0.040(3) at a temperature of 134(3) nK, more than 3,000 times colder than previously realized tetratomic molecules12. We observe a maximum tetramer lifetime of 8(2) ms in free space without a notable change in the presence of an optical dipole trap, indicating that these tetramers are collisionally stable. Moreover, we directly image the dissociated tetramers through microwave-field modulation to probe the anisotropy of their wavefunction in momentum space. Our result demonstrates a universal tool for assembling weakly bound ultracold polyatomic molecules from smaller polar molecules, which is a crucial step towards Bose-Einstein condensation of polyatomic molecules and towards a new crossover from a dipolar Bardeen-Cooper-Schrieffer superfluid13-15 to a Bose-Einstein condensation of tetramers. Moreover, the long-lived field-linked state provides an ideal starting point for deterministic optical transfer to deeply bound tetramer states16-18.

2.
Nature ; 614(7946): 59-63, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36725996

RESUMO

Scattering resonances are an essential tool for controlling the interactions of ultracold atoms and molecules. However, conventional Feshbach scattering resonances1, which have been extensively studied in various platforms1-7, are not expected to exist in most ultracold polar molecules because of the fast loss that occurs when two molecules approach at a close distance8-10. Here we demonstrate a new type of scattering resonance that is universal for a wide range of polar molecules. The so-called field-linked resonances11-14 occur in the scattering of microwave-dressed molecules because of stable macroscopic tetramer states in the intermolecular potential. We identify two resonances between ultracold ground-state sodium-potassium molecules and use the microwave frequencies and polarizations to tune the inelastic collision rate by three orders of magnitude, from the unitary limit to well below the universal regime. The field-linked resonance provides a tuning knob to independently control the elastic contact interaction and the dipole-dipole interaction, which we observe as a modification in the thermalization rate. Our result provides a general strategy for resonant scattering between ultracold polar molecules, which paves the way for realizing dipolar superfluids15 and molecular supersolids16, as well as assembling ultracold polyatomic molecules.

3.
Nat Immunol ; 17(5): 565-73, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27043411

RESUMO

Positive selection occurs in the thymic cortex, but critical maturation events occur later in the medulla. Here we defined the precise stage at which T cells acquired competence to proliferate and emigrate. Transcriptome analysis of late gene changes suggested roles for the transcription factor NF-κB and interferon signaling. Mice lacking the inhibitor of NF-κB (IκB) kinase (IKK) kinase TAK1 underwent normal positive selection but exhibited a specific block in functional maturation. NF-κB signaling provided protection from death mediated by the cytokine TNF and was required for proliferation and emigration. The interferon signature was independent of NF-κB; however, thymocytes deficient in the interferon-α (IFN-α) receptor IFN-αR showed reduced expression of the transcription factor STAT1 and phenotypic abnormality but were able to proliferate. Thus, both NF-κB and tonic interferon signals are involved in the final maturation of thymocytes into naive T cells.


Assuntos
Diferenciação Celular/imunologia , NF-kappa B/imunologia , Receptor de Interferon alfa e beta/imunologia , Linfócitos T/imunologia , Timo/imunologia , Animais , Diferenciação Celular/genética , Movimento Celular/genética , Movimento Celular/imunologia , Proliferação de Células/genética , Citometria de Fluxo , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/imunologia , MAP Quinase Quinase Quinases/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , NF-kappa B/genética , NF-kappa B/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Receptor de Interferon alfa e beta/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/imunologia , Fator de Transcrição STAT1/metabolismo , Linfócitos T/metabolismo , Timócitos/imunologia , Timócitos/metabolismo , Timo/citologia , Timo/metabolismo , Transcriptoma/genética , Transcriptoma/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo
4.
Nature ; 607(7920): 677-681, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35896646

RESUMO

Ultracold polar molecules offer strong electric dipole moments and rich internal structure, which makes them ideal building blocks to explore exotic quantum matter1-9, implement quantum information schemes10-12 and test the fundamental symmetries of nature13. Realizing their full potential requires cooling interacting molecular gases deeply into the quantum-degenerate regime. However, the intrinsically unstable collisions between molecules at short range have so far prevented direct cooling through elastic collisions to quantum degeneracy in three dimensions. Here we demonstrate evaporative cooling of a three-dimensional gas of fermionic sodium-potassium molecules to well below the Fermi temperature using microwave shielding. The molecules are protected from reaching short range with a repulsive barrier engineered by coupling rotational states with a blue-detuned circularly polarized microwave. The microwave dressing induces strong tunable dipolar interactions between the molecules, leading to high elastic collision rates that can exceed the inelastic ones by at least a factor of 460. This large elastic-to-inelastic collision ratio allows us to cool the molecular gas to 21 nanokelvin, corresponding to 0.36 times the Fermi temperature. Such cold and dense samples of polar molecules open the path to the exploration of many-body phenomena with strong dipolar interactions.

5.
Nat Immunol ; 16(1): 107-17, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25419629

RESUMO

The strength with which complexes of self peptide and major histocompatibility complex (MHC) proteins are recognized by the T cell antigen receptor (TCR) dictates the homeostasis of naive CD8(+) T cells, but its effect on reactivity to foreign antigens is controversial. As expression of the negative regulator CD5 correlates with self-recognition, we studied CD5(lo) and CD5(hi) naive CD8(+) T cells. Gene-expression characteristics suggested CD5(hi) cells were better poised for reactivity and differentiation than were CD5(lo) cells, and we found that the CD5(hi) pool also exhibited more efficient clonal recruitment and expansion, as well as enhanced reactivity to inflammatory cues, during the recognition of foreign antigen. However, the recognition of complexes of foreign peptide and MHC was similar for both subsets. Thus, CD8(+) T cells with higher self-reactivity dominate the immune response to foreign antigens, with implications for T cell repertoire diversity and autoimmunity.


Assuntos
Autoantígenos/imunologia , Antígenos CD5/imunologia , Linfócitos T CD8-Positivos/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Feminino , Citometria de Fluxo , Perfilação da Expressão Gênica , Homeostase/imunologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Fenótipo , Organismos Livres de Patógenos Específicos
6.
Nat Immunol ; 16(10): 1069-76, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26301566

RESUMO

In the thymus, low-affinity T cell antigen receptor (TCR) engagement facilitates positive selection of a useful T cell repertoire. Here we report that TCR responsiveness of mature CD8(+) T cells is fine tuned by their affinity for positively selecting peptides in the thymus and that optimal TCR responsiveness requires positive selection on major histocompatibility complex class I-associated peptides produced by the thymoproteasome, which is specifically expressed in the thymic cortical epithelium. Thymoproteasome-independent positive selection of monoclonal CD8(+) T cells results in aberrant TCR responsiveness, homeostatic maintenance and immune responses to infection. These results demonstrate a novel aspect of positive selection, in which TCR affinity for positively selecting peptides produced by thymic epithelium determines the subsequent antigen responsiveness of mature CD8(+) T cells in the periphery.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Complexo de Endopeptidases do Proteassoma/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Proliferação de Células , Citometria de Fluxo , Camundongos , Peptídeos/imunologia , Timo/enzimologia
7.
Nat Immunol ; 15(5): 473-81, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24633226

RESUMO

Regulatory T cells (Treg cells) express members of the tumor-necrosis factor (TNF) receptor superfamily (TNFRSF), but the role of those receptors in the thymic development of Treg cells is undefined. We found here that Treg cell progenitors had high expression of the TNFRSF members GITR, OX40 and TNFR2. Expression of those receptors correlated directly with the signal strength of the T cell antigen receptor (TCR) and required the coreceptor CD28 and the kinase TAK1. The neutralization of ligands that are members of the TNF superfamily (TNFSF) diminished the development of Treg cells. Conversely, TNFRSF agonists enhanced the differentiation of Treg cell progenitors by augmenting responsiveness of the interleukin 2 receptor (IL-2R) and transcription factor STAT5. Costimulation with the ligand of GITR elicited dose-dependent enrichment for cells of lower TCR affinity in the Treg cell repertoire. In vivo, combined inhibition of GITR, OX40 and TNFR2 abrogated the development of Treg cells. Thus, expression of members of the TNFRSF on Treg cell progenitors translated strong TCR signals into molecular parameters that specifically promoted the development of Treg cells and shaped the Treg cell repertoire.


Assuntos
Receptor Cross-Talk , Receptores de Antígenos de Linfócitos T/agonistas , Linfócitos T Reguladores/imunologia , Timo/imunologia , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral/metabolismo , Animais , Antígenos CD28/genética , Antígenos CD28/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Proteína Relacionada a TNFR Induzida por Glucocorticoide/genética , Proteína Relacionada a TNFR Induzida por Glucocorticoide/metabolismo , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor Cross-Talk/imunologia , Receptores OX40/genética , Receptores OX40/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologia , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais/genética , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose Tumoral/genética
8.
Proc Natl Acad Sci U S A ; 120(24): e2219649120, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37276408

RESUMO

How left-right (LR) asymmetry emerges in a patterning field along the anterior-posterior axis remains an unresolved problem in developmental biology. Left-biased Nodal emanating from the LR organizer propagates from posterior to anterior (PA) and establishes the LR pattern of the whole embryo. However, little is known about the regulatory mechanism of the PA spread of Nodal and its asymmetric activation in the forebrain. Here, we identify bilaterally expressed Follistatin (Fst) as a regulator blocking the propagation of the zebrafish Nodal ortholog Southpaw (Spaw) in the right lateral plate mesoderm (LPM), and restricting Spaw transmission in the left LPM to facilitate the establishment of a robust LR asymmetric Nodal patterning. In addition, Fst inhibits the Activin-Nodal signaling pathway in the forebrain thus preventing Nodal activation prior to the arrival, at a later time, of Spaw emanating from the left LPM. This contributes to the orderly propagation of asymmetric Nodal activation along the PA axis. The LR regulation function of Fst is further confirmed in chick and frog embryos. Overall, our results suggest that a robust LR patterning emerges by counteracting a Fst barrier formed along the PA axis.


Assuntos
Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo , Folistatina/genética , Folistatina/metabolismo , Padronização Corporal/genética , Fator de Crescimento Transformador beta/metabolismo , Regulação da Expressão Gênica no Desenvolvimento
9.
PLoS Biol ; 20(11): e3001856, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36318514

RESUMO

Feingold syndrome type 1, caused by loss-of-function of MYCN, is characterized by varied phenotypes including esophageal and duodenal atresia. However, no adequate model exists for studying the syndrome's pathological or molecular mechanisms, nor is there a treatment strategy. Here, we developed a zebrafish Feingold syndrome type 1 model with nonfunctional mycn, which had severe intestinal atresia. Single-cell RNA-seq identified a subcluster of intestinal cells that were highly sensitive to Mycn, and impaired cell proliferation decreased the overall number of intestinal cells in the mycn mutant fish. Bulk RNA-seq and metabolomic analysis showed that expression of ribosomal genes was down-regulated and that amino acid metabolism was abnormal. Northern blot and ribosomal profiling analysis showed abnormal rRNA processing and decreases in free 40S, 60S, and 80S ribosome particles, which led to impaired translation in the mutant. Besides, both Ribo-seq and western blot analysis showed that mTOR pathway was impaired in mycn mutant, and blocking mTOR pathway by rapamycin treatment can mimic the intestinal defect, and both L-leucine and Rheb, which can elevate translation via activating TOR pathway, could rescue the intestinal phenotype of mycn mutant. In summary, by this zebrafish Feingold syndrome type 1 model, we found that disturbance of ribosomal biogenesis and blockage of protein synthesis during development are primary causes of the intestinal defect in Feingold syndrome type 1. Importantly, our work suggests that leucine supplementation may be a feasible and easy treatment option for this disease.


Assuntos
Microcefalia , Peixe-Zebra , Animais , Proteína Proto-Oncogênica N-Myc , Peixe-Zebra/metabolismo , Microcefalia/genética , Serina-Treonina Quinases TOR/metabolismo , Leucina
10.
Mol Cell Proteomics ; 22(2): 100494, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36621768

RESUMO

AMP-activated protein kinase alpha 2 (AMPKα2) regulates energy metabolism, protein synthesis, and glucolipid metabolism myocardial cells. Ketone bodies produced by fatty acid ß-oxidation, especially ß-hydroxybutyrate, are fatty energy-supplying substances for the heart, brain, and other organs during fasting and long-term exercise. They also regulate metabolic signaling for multiple cellular functions. Lysine ß-hydroxybutyrylation (Kbhb) is a ß-hydroxybutyrate-mediated protein posttranslational modification. Histone Kbhb has been identified in yeast, mouse, and human cells. However, whether AMPK regulates protein Kbhb is yet unclear. Hence, the present study explored the changes in proteomics and Kbhb modification omics in the hearts of AMPKα2 knockout mice using a comprehensive quantitative proteomic analysis. Based on mass spectrometry (LC-MS/MS) analysis, the number of 1181 Kbhb modified sites in 455 proteins were quantified between AMPKα2 knockout mice and wildtype mice; 244 Kbhb sites in 142 proteins decreased or increased after AMPKα2 knockout (fold change >1.5 or <1/1.5, p < 0.05). The regulation of Kbhb sites in 26 key enzymes of fatty acid degradation and tricarboxylic acid cycle was noted in AMPKα2 knockout mouse cardiomyocytes. These findings, for the first time, identified proteomic features and Kbhb modification of cardiomyocytes after AMPKα2 knockout, suggesting that AMPKα2 regulates energy metabolism by modifying protein Kbhb.


Assuntos
Ácido 3-Hidroxibutírico , Proteínas Quinases Ativadas por AMP , Miocárdio , Animais , Humanos , Camundongos , Ácido 3-Hidroxibutírico/química , Ácido 3-Hidroxibutírico/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Cromatografia Líquida , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miocárdio/metabolismo , Proteômica , Espectrometria de Massas em Tandem
11.
Breast Cancer Res ; 26(1): 40, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459598

RESUMO

BACKGROUND: 99mTc radiolabeled nanobody NM-02 (99mTc-NM-02) is a novel single photon emission computed tomography (SPECT) probe with a high affinity and specificity for human epidermal growth factor receptor 2 (HER2). In this study, a clinical imaging trial was conducted to investigate the relationship between 99mTc-NM-02 uptake and HER2 expression in patients with breast cancer. METHODS: Thirty patients with pathologically confirmed breast cancer were recruited and imaged with both 99mTc-NM-02 SPECT/computed tomography (CT) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT. According to the treatment conditions before recruitment, patients were divided into two groups, the newly diagnosed group (n = 24) and the treated group (n = 6). The maximal standard uptake value (SUVmax) of 18F-FDG and SUVmax and mean SUV (SUVmean) of 99mTc-NM-02 in the lesions were determined to analyze the relationship with HER2 expression. RESULTS: No meaningful relationship was observed between 18F-FDG uptake and HER2 expression in 30 patients with breast cancer. 99mTc-NM-02 uptake was positively correlated with HER2 expression in the newly diagnosed group, but no correlation was observed in the treated group. 99mTc-NM-02 uptake in HER2-positive lesions was lower in those with effective HER2-targeted therapy compared with the newly diagnosed group. 99mTc-NM-02 SPECT/CT detected brain and bone metastases of breast cancer with a different imaging pattern from 18F-FDG PET/CT. 99mTc-NM-02 showed no non-specific uptake in inflamed tissues and revealed intra- and intertumoral HER2 heterogeneity by SPECT/CT imaging in 9 of the 30 patients with breast cancer. CONCLUSIONS: 99mTc-NM-02 SPECT/CT has the potential for visualizing whole-body HER2 overexpression in untreated patients, making it a promising method for HER2 assessment in patients with breast cancer. TRIAL REGISTRATION: NCT04674722, Date of registration: December 19, 2020.


Assuntos
Neoplasias Ósseas , Neoplasias da Mama , Receptor ErbB-2 , Feminino , Humanos , Neoplasias Ósseas/secundário , Neoplasias da Mama/diagnóstico por imagem , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons/métodos , Receptor ErbB-2/imunologia , Receptor ErbB-2/metabolismo , Anticorpos de Domínio Único
12.
Opt Express ; 32(4): 5705-5717, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38439289

RESUMO

We propose a large viewing angle integral imaging 3D display system based on a symmetrical compound lens array (SCLA). The display system comprises a high-resolution 2D display panel, an SCLA, and a light shaping diffuser. The high-resolution 2D display panel presents an elemental image array, the SCLA modulates the light rays emitted from the 2D display panel to form 3D images in space, and the light shaping diffuser eliminates the gaps between 3D pixels of the 3D images. We find that the lateral aberration is a crucial factor that affects the resolution of the reconstructed 3D image. The symmetrical structure of the SCLA enables a reduced focal length and the elimination of lateral aberration, improving the viewing angle and the 3D image resolution simultaneously. The experimental results confirm that the proposed display system increases the viewing angle to 68.6°, achieving a comparable resolution of the full field of view while maintaining a simple structure.

13.
Invest New Drugs ; 42(3): 241-251, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38483782

RESUMO

MEK inhibitors have immunomodulatory activity and potential for synergistic activity when combined with PD-1 inhibitors. We evaluated selumetinib (inhibitor of MEK1/2) plus pembrolizumab (anti‒PD-1 antibody) in patients with advanced/metastatic solid tumors. In this phase 1b study, adults with previously treated advanced/metastatic solid tumors received pembrolizumab 200 mg intravenously every 3 weeks plus selumetinib on days 1‒14 per 3-week cycle (2 weeks on/1 week off); selumetinib dosing began at 50 mg orally twice daily with escalation in 25 mg increments for ≤ 35 cycles. Primary endpoints were dose-limiting toxicities (DLTs), adverse events (AEs), and treatment discontinuations due to AEs. Thirty-two patients were enrolled. Dose escalation was completed up to selumetinib 125 mg twice daily. The target DLT rate of 30% was not reached at any dose level. In the selumetinib 100 mg group, 2/11 patients (18.2%) experienced DLTs (n = 1 grade 3 diarrhea, n = 1 grade 3 fatigue). In the selumetinib 125 mg group, 3/14 (21.4%) experienced DLTs (n = 1 grade 2 retinal detachment, n = 1 grade 3 retinopathy, n = 1 grade 3 stomatitis). Dose-related changes in pharmacokinetic exposures were observed for selumetinib and N-desmethyl selumetinib up to 100 mg (saturation at 125 mg). Two patients achieved partial responses (1 each with selumetinib 75 mg and 125 mg) for an objective response rate of 6%. The study was stopped early because of insufficient efficacy. Although the target DLT rate was not reached at any dose level and no new safety signals were identified, selumetinib plus pembrolizumab had limited antitumor activity in this population. Trial registration: ClinicalTrials.gov , NCT03833427.


Assuntos
Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Benzimidazóis , Neoplasias , Humanos , Benzimidazóis/administração & dosagem , Benzimidazóis/farmacocinética , Benzimidazóis/uso terapêutico , Benzimidazóis/efeitos adversos , Feminino , Masculino , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/farmacocinética , Anticorpos Monoclonais Humanizados/uso terapêutico , Pessoa de Meia-Idade , Idoso , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Adulto , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/farmacocinética , Inibidores de Proteínas Quinases/uso terapêutico , Dose Máxima Tolerável , Relação Dose-Resposta a Droga , Idoso de 80 Anos ou mais
14.
Langmuir ; 40(20): 10663-10675, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38718299

RESUMO

Electrocatalytic reduction (ECR) of CO2 to chemical products is an important carbon emission reduction method. This work uses DFT to study the stability of N-doped graphene-supported four metal single-atom catalysts (M-N-C) and the effects of the coordination environment and metal centers on the selectivity of CO2 ECR to C1 products. The results show that Fe, Co, Ni, and Cu have good stability. The coordination environment has a significant modulating effect on product selectivity, and the change of the number of ligand nitrogen atoms will affect the size of the potential-limiting step of each product. When the number of nitrogen ligands is the same, the different metal centers of the M-N-C catalyst have a significant effect on the selectivity of different products. In addition, the introduction of nitrogen atom ligands can adjust the electronic structure of the graphene-supported metal center, increase the d-band center of most metals, and improve the reaction activity.

15.
Bioorg Chem ; 147: 107356, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38604021

RESUMO

Developing "turn on" fluorescent probes was desirable for the detection of the effective anticoagulant agent heparin in clinical applications. Through combining the aggregation induced emission (AIE) fluorogen tetraphenylethene (TPE) and heparin specific binding peptide AG73, the promising "turn on" fluorescent probe TPE-1 has been developed. Nevertheless, although TPE-1 could achieve the sensitive and selective detection of heparin, the low proteolytic stability and undesirable poor solubility may limit its widespread applications. In this study, seven TPE-1 derived fluorescent probes were rationally designed, efficiently synthesized and evaluated. The stability and water solubility were systematically estimated. Especially, to achieve real-time monitoring of proteolytic stability, the novel Abz/Dnp-based "turn on" probes that employ the internally quenched fluorescent (IQF) mechanism were designed and synthesized. Moreover, the detection ability of synthetic fluorescent probes for heparin were systematically evaluated. Importantly, the performance of d-type peptide fluorescent probe XH-6 indicated that d-type amino acid substitutions could significantly improve the proteolytic stability without compromising its ability of heparin sensing, and attaching solubilizing tag 2-(2-aminoethoxy) ethoxy) acid (AEEA) could greatly enhance the solubility. Collectively, this study not only established practical strategies to improve both the water solubility and proteolytic stability of "turn on" fluorescent probes for heparin sensing, but also provided valuable references for the subsequent development of enzymatic hydrolysis-resistant d-type peptides based fluorescent probes.


Assuntos
Corantes Fluorescentes , Heparina , Peptídeos , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Heparina/análise , Heparina/química , Peptídeos/química , Peptídeos/síntese química , Estrutura Molecular , Humanos , Espectrometria de Fluorescência
16.
Surg Endosc ; 38(4): 1709-1722, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38413470

RESUMO

BACKGROUND: Postoperative anastomotic leakage (PAL) is a serious complication of gastric cancer surgery. Although perioperative management has made considerable progress, anastomotic leakage (AL) cannot always be avoided. The purpose of this study is to evaluate whether intraoperative leak testing (IOLT) can reduce the incidence of PAL and other postoperative outcomes in gastric cancer surgery. MATERIALS AND METHODS: In this meta-analysis, we searched the PubMed, Embase, and Cochrane Library databases for clinical trials to assess the application of IOLT in gastric cancer surgery. All patients underwent laparoscopic radical gastrectomy for gastric cancer surgery. Studies comparing the postoperative outcomes of IOLT and no intraoperative leak testing (NIOLT) were included. Quality assessment, heterogeneity, risk of bias, and the level of evidence of the included studies were evaluated. PAL, anastomotic-related complications, 30-day mortality, and reoperation rates were compared between the IOLT and NIOLT group. RESULTS: Our literature search returned 721 results, from which six trials (a total of 1,666 patients) were included in our meta-analysis. Statistical heterogeneity was low. The primary outcome was PAL. IOLT reduced the incidence of PAL [2.09% vs 6.68%; (RR = 0.31, 95% Cl 0.19-0.53, P < 0.0001]. Anastomotic-related complications, which included bleeding, leakage, and stricture, were significantly higher in the NIOLT group than in the IOLT group [3.24% VS 10.85%; RR = 0.30, 95% Cl 0.18-0.53, P < 0.0001]. Moreover, IOLT was associated with lower reoperation rates [0.94% vs 6.83%; RR = 0.18, 95% CI 0.07-0.43, P = 0.0002]. CONCLUSION: Considering the observed lower incidence of postoperative anastomotic leakage (PAL), anastomotic-related complications, and reoperation rates, IOLT appears to be a promising option for gastric cancer surgery. It warrants further study before potential inclusion in future clinical guidelines.


Assuntos
Fístula Anastomótica , Neoplasias Gástricas , Humanos , Fístula Anastomótica/epidemiologia , Fístula Anastomótica/etiologia , Fístula Anastomótica/prevenção & controle , Neoplasias Gástricas/cirurgia , Neoplasias Gástricas/complicações , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Gastrectomia/efeitos adversos , Gastrectomia/métodos , Anastomose Cirúrgica/efeitos adversos
17.
Nutr Metab Cardiovasc Dis ; 34(6): 1518-1527, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38508991

RESUMO

BACKGROUND AND AIMS: The role of serum uric acid (SUA) in the prognosis of chronic kidney disease (CKD) is inconclusive. To explore the association of SUA level with all-cause and cardiovascular disease (CVD) mortality in patients with CKD. METHODS AND RESULTS: Leveraging data from the National Health and Nutritional Examination Survey (NHANES) and linked national death records up to December 31 2019, we explored the association of SUA with all-cause and CVD mortality using weighted cox proportional hazards regression models and restricted cubic spline (RCS) models in patients with CKD stages 3-5. The study finally included 2644 patients with CKD stages 3-5, with a median SUA level of 6.5 mg/dL. After a median follow-up of 55 months, a total of 763 deaths were recorded, with 279 of them attributed to CVD. In the fully adjusted model, per 1 mg/dL increment in SUA concentration was found to be associated with increased HRs (95% CIs) of 1.07 (1.00, 1.14) for all-cause mortality and 1.11 (1.00, 1.24) for CVD mortality. Compared to Q2 (reference), those in Q4 had adjusted HRs of 1.72 (1.36, 2.17) for all-cause mortality and 2.17 (1.38, 3.41) for CVD mortality, while those in Q1 had adjusted HRs of 1.49 (1.19, 1.85) for all-cause mortality and 1.93 (1.26, 2.98) for CVD mortality. CONCLUSIONS: Both higher and lower SUA levels were associated with increased risks of all-cause and CVD mortality in patients with CKD stages 3-5.


Assuntos
Biomarcadores , Doenças Cardiovasculares , Causas de Morte , Hiperuricemia , Inquéritos Nutricionais , Insuficiência Renal Crônica , Ácido Úrico , Humanos , Ácido Úrico/sangue , Masculino , Feminino , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico , Insuficiência Renal Crônica/mortalidade , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/diagnóstico , Pessoa de Meia-Idade , Medição de Risco , Biomarcadores/sangue , Idoso , Hiperuricemia/sangue , Hiperuricemia/mortalidade , Hiperuricemia/diagnóstico , Fatores de Tempo , Prognóstico , Estados Unidos/epidemiologia , Fatores de Risco , Adulto , Fatores de Risco de Doenças Cardíacas
19.
Biochem Genet ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38656671

RESUMO

Elderly patients infected with severe acute respiratory syndrome coronavirus 2 are at higher risk of severe clinical manifestation, extended hospitalization, and increased mortality. Those patients are more likely to experience persistent symptoms and exacerbate the condition of basic diseases with long COVID-19 syndrome. However, the molecular mechanisms underlying severe COVID-19 in the elderly patients remain unclear. Our study aims to investigate the function of the interaction between disease-characteristic genes and immune cell infiltration in patients with severe COVID-19 infection. COVID-19 datasets (GSE164805 and GSE180594) and aging dataset (GSE69832) were obtained from the Gene Expression Omnibus database. The combined different expression genes (DEGs) were subjected to Gene Ontology (GO) functional enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Diseases Ontology functional enrichment analysis, Gene Set Enrichment Analysis, machine learning, and immune cell infiltration analysis. GO and KEGG enrichment analyses revealed that the eight DEGs (IL23A, PTGER4, PLCB1, IL1B, CXCR1, C1QB, MX2, ALOX12) were mainly involved in inflammatory mediator regulation of TRP channels, coronavirus disease-COVID-19, and cytokine activity signaling pathways. Three-degree algorithm (LASSO, SVM-RFE, KNN) and correlation analysis showed that the five DEGs up-regulated the immune cells of macrophages M0/M1, memory B cells, gamma delta T cell, dendritic cell resting, and master cell resisting. Our study identified five hallmark genes that can serve as disease-characteristic genes and target immune cells infiltrated in severe COVID-19 patients among the elderly population, which may contribute to the study of pathogenesis and the evaluation of diagnosis and prognosis in aging patients infected with severe COVID-19.

20.
J Obstet Gynaecol Res ; 50(3): 478-484, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38072997

RESUMO

AIM: The aim of this study was to investigate how the integration status of HPV in the vaginal epithelium affects the development of vaginal intraepithelial neoplasia (VaIN). METHODS: Twenty-four vaginal tissues were collected before applying high-throughput viral integration detection (HIVID), medical records of them were documented, including age, thin-prep cytologic test (TCT) and HPV test results, colposcopic biopsy pathology, and other clinical data, such as history of total hysterectomy for cervical lesions, whether they were infected with HPV16/18 with a follow-up span of 2 years. We summarized the distribution of HPV integration on the host chromosome and HPV type, as well as the hotspot integration gene and its role in the development of VaIN. RESULTS: In this study, 24 cases suffered from VaIN were involved. HPV integration was detected in 11 cases; furthermore, we discovered HPV 16 and 73, chromosome 1 and 2 possessed most HPV integration sites while EMBP1, CLO5A1, EHF, ELF5 as dominate hot spots. Taken clinical outcome into account, we found a significant difference between HPV integration occurrence and VaIN (p = 0.011). CONCLUSION: (1) This study found a statistical difference between HPV integration and the occurrence of VaIN; (2) HPV integration may provide a new clinical predictor for VaIN and facilitate risk assessment and stratified management of high-risk patients.


Assuntos
Neoplasias , Infecções por Papillomavirus , Feminino , Humanos , Pré-Escolar , Papillomavirus Humano 16 , Papillomavirus Humano 18 , Infecções por Papillomavirus/complicações , Biópsia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA