Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.535
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 618(7966): 712-715, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37286602

RESUMO

The most massive and shortest-lived stars dominate the chemical evolution of the pre-galactic era. On the basis of numerical simulations, it has long been speculated that the mass of such first-generation stars was up to several hundred solar masses1-4. The very massive first-generation stars with a mass range from 140 to 260 solar masses are predicted to enrich the early interstellar medium through pair-instability supernovae (PISNe)5. Decades of observational efforts, however, have not been able to uniquely identify the imprints of such very massive stars on the most metal-poor stars in the Milky Way6,7. Here we report the chemical composition of a very metal-poor (VMP) star with extremely low sodium and cobalt abundances. The sodium with respect to iron in this star is more than two orders of magnitude lower than that of the Sun. This star exhibits very large abundance variance between the odd- and even-charge-number elements, such as sodium/magnesium and cobalt/nickel. Such peculiar odd-even effect, along with deficiencies of sodium and α elements, are consistent with the prediction of primordial pair-instability supernova (PISN) from stars more massive than 140 solar masses. This provides a clear chemical signature indicating the existence of very massive stars in the early universe.

2.
Development ; 151(14)2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39036998

RESUMO

We present a new set of computational tools that enable accurate and widely applicable 3D segmentation of nuclei in various 3D digital organs. We have developed an approach for ground truth generation and iterative training of 3D nuclear segmentation models, which we applied to popular CellPose, PlantSeg and StarDist algorithms. We provide two high-quality models trained on plant nuclei that enable 3D segmentation of nuclei in datasets obtained from fixed or live samples, acquired from different plant and animal tissues, and stained with various nuclear stains or fluorescent protein-based nuclear reporters. We also share a diverse high-quality training dataset of about 10,000 nuclei. Furthermore, we advanced the MorphoGraphX analysis and visualization software by, among other things, providing a method for linking 3D segmented nuclei to their surrounding cells in 3D digital organs. We found that the nuclear-to-cell volume ratio varies between different ovule tissues and during the development of a tissue. Finally, we extended the PlantSeg 3D segmentation pipeline with a proofreading tool that uses 3D segmented nuclei as seeds to correct cell segmentation errors in difficult-to-segment tissues.


Assuntos
Núcleo Celular , Aprendizado Profundo , Imageamento Tridimensional , Software , Núcleo Celular/metabolismo , Imageamento Tridimensional/métodos , Animais , Algoritmos , Arabidopsis , Processamento de Imagem Assistida por Computador/métodos
3.
Mol Cell ; 72(6): 999-1012.e6, 2018 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-30449722

RESUMO

Double-stranded RNA (dsRNA) is a potent proinflammatory signature of viral infection. Long cytosolic dsRNA is recognized by MDA5. The cooperative assembly of MDA5 into helical filaments on dsRNA nucleates the assembly of a multiprotein type I interferon signaling platform. Here, we determined cryoelectron microscopy (cryo-EM) structures of MDA5-dsRNA filaments with different helical twists and bound nucleotide analogs at resolutions sufficient to build and refine atomic models. The structures identify the filament-forming interfaces, which encode the dsRNA binding cooperativity and length specificity of MDA5. The predominantly hydrophobic interface contacts confer flexibility, reflected in the variable helical twist within filaments. Mutation of filament-forming residues can result in loss or gain of signaling activity. Each MDA5 molecule spans 14 or 15 RNA base pairs, depending on the twist. Variations in twist also correlate with variations in the occupancy and type of nucleotide in the active site, providing insights on how ATP hydrolysis contributes to MDA5-dsRNA recognition.


Assuntos
Trifosfato de Adenosina/metabolismo , Microscopia Crioeletrônica , Helicase IFIH1 Induzida por Interferon/ultraestrutura , RNA de Cadeia Dupla/ultraestrutura , Células HEK293 , Humanos , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Helicase IFIH1 Induzida por Interferon/genética , Helicase IFIH1 Induzida por Interferon/metabolismo , Interferon beta/genética , Interferon beta/metabolismo , Simulação de Acoplamento Molecular , Mutação , Conformação de Ácido Nucleico , Conformação Proteica , RNA de Cadeia Dupla/metabolismo , Transdução de Sinais , Relação Estrutura-Atividade
4.
Proc Natl Acad Sci U S A ; 120(1): e2213437120, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36580587

RESUMO

ABCG2 is an ATP-binding cassette (ABC) transporter that extrudes a wide range of xenobiotics and drugs from the cell and contributes to multidrug resistance in cancer cells. Following our recent structural characterization of topotecan-bound ABCG2, here, we present cryo-EM structures of ABCG2 under turnover conditions in complex with a special modulator and slow substrate, tariquidar, in nanodiscs. The structures reveal that similar to topotecan, tariquidar induces two distinct ABCG2 conformations under turnover conditions (turnover-1 and turnover-2). µs-scale molecular dynamics simulations of drug-bound and apo ABCG2 in native-like lipid bilayers, in both topotecan- and tariquidar-bound states, characterize the ligand size as a major determinant of its binding stability. The simulations highlight direct lipid-drug interactions for the smaller topotecan, which exhibits a highly dynamic binding mode. In contrast, the larger tariquidar occupies most of the available volume in the binding pocket, thus leaving little space for lipids to enter the cavity and interact with it. Similarly, when simulating ABCG2 in the apo inward-open state, we also observe spontaneous penetration of phospholipids into the binding cavity. The captured phospholipid diffusion pathway into ABCG2 offers a putative general path to recruit any hydrophobic/amphiphilic substrates directly from the membrane. Our simulations also reveal that ABCG2 rejects cholesterol as a substrate, which is omnipresent in plasma membranes that contain ABCG2. At the same time, cholesterol is found to prohibit the penetration of phospholipids into ABCG2. These molecular findings have direct functional ramifications on ABCG2's function as a transporter.


Assuntos
Resistência a Múltiplos Medicamentos , Topotecan , Ligantes , Transportadores de Cassetes de Ligação de ATP/metabolismo , Fosfolipídeos , Colesterol , Resistencia a Medicamentos Antineoplásicos
5.
Proc Natl Acad Sci U S A ; 120(15): e2218673120, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37014854

RESUMO

High- (and medium-) entropy alloys have emerged as potentially suitable structural materials for nuclear applications, particularly as they appear to show promising irradiation resistance. Recent studies have provided evidence of the presence of local chemical order (LCO) as a salient feature of these complex concentrated solid-solution alloys. However, the influence of such LCO on their irradiation response has remained uncertain thus far. In this work, we combine ion irradiation experiments with large-scale atomistic simulations to reveal that the presence of chemical short-range order, developed as an early stage of LCO, slows down the formation and evolution of point defects in the equiatomic medium-entropy alloy CrCoNi during irradiation. In particular, the irradiation-induced vacancies and interstitials exhibit a smaller difference in their mobility, arising from a stronger effect of LCO in localizing interstitial diffusion. This effect promotes their recombination as the LCO serves to tune the migration energy barriers of these point defects, thereby delaying the initiation of damage. These findings imply that local chemical ordering may provide a variable in the design space to enhance the resistance of multi-principal element alloys to irradiation damage.

6.
Proc Natl Acad Sci U S A ; 120(15): e2220608120, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37018199

RESUMO

A precise modulation of heterogeneous catalysts in structural and surface properties promises the development of more sustainable advanced oxidation water purification technologies. However, while catalysts with superior decontamination activity and selectivity are already achievable, maintaining a long-term service life of such materials remains challenging. Here, we propose a crystallinity engineering strategy to break the activity-stability tradeoff of metal oxides in Fenton-like catalysis. The amorphous/crystalline cobalt-manganese spinel oxide (A/C-CoMnOx) provided highly active, hydroxyl group-rich surface, with moderate peroxymonosulfate (PMS)-binding affinity and charge transfer energy and strong pollutant adsorption, to trigger concerted radical and nonradical reactions for efficient pollutant mineralization, thereby alleviating the catalyst passivation by oxidation intermediate accumulation. Meanwhile, the surface-confined reactions, benefited from the enhanced adsorption of pollutants at A/C interface, rendered the A/C-CoMnOx/PMS system ultrahigh PMS utilization efficiency (82.2%) and unprecedented decontamination activity (rate constant of 1.48 min-1) surpassing almost all the state-of-the-art heterogeneous Fenton-like catalysts. The superior cyclic stability and environmental robustness of the system for real water treatment was also demonstrated. Our work unveils a critical role of material crystallinity in modulating the Fenton-like catalytic activity and pathways of metal oxides, which fundamentally improves our understanding of the structure-activity-selectivity relationships of heterogeneous catalysts and may inspire material design for more sustainable water purification application and beyond.

7.
Nature ; 570(7761): 358-362, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31217599

RESUMO

The ability to manipulate the twisting topology of van der Waals structures offers a new degree of freedom through which to tailor their electrical and optical properties. The twist angle strongly affects the electronic states, excitons and phonons of the twisted structures through interlayer coupling, giving rise to exotic optical, electric and spintronic behaviours1-5. In twisted bilayer graphene, at certain twist angles, long-range periodicity associated with moiré patterns introduces flat electronic bands and highly localized electronic states, resulting in Mott insulating behaviour and superconductivity3,4. Theoretical studies suggest that these twist-induced phenomena are common to layered materials such as transition-metal dichalcogenides and black phosphorus6,7. Twisted van der Waals structures are usually created using a transfer-stacking method, but this method cannot be used for materials with relatively strong interlayer binding. Facile bottom-up growth methods could provide an alternative means to create twisted van der Waals structures. Here we demonstrate that the Eshelby twist, which is associated with a screw dislocation (a chiral topological defect), can drive the formation of such structures on scales ranging from the nanoscale to the mesoscale. In the synthesis, axial screw dislocations are first introduced into nanowires growing along the stacking direction, yielding van der Waals nanostructures with continuous twisting in which the total twist rates are defined by the radii of the nanowires. Further radial growth of those twisted nanowires that are attached to the substrate leads to an increase in elastic energy, as the total twist rate is fixed by the substrate. The stored elastic energy can be reduced by accommodating the fixed twist rate in a series of discrete jumps. This yields mesoscale twisting structures consisting of a helical assembly of nanoplates demarcated by atomically sharp interfaces with a range of twist angles. We further show that the twisting topology can be tailored by controlling the radial size of the structure.

8.
Plant J ; 115(2): 317-334, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37009643

RESUMO

Frequent herbicide use selects for herbicide resistance in weeds. Cytochrome P450s are important detoxification enzymes responsible for herbicide resistance in plants. We identified and characterized a candidate P450 gene (BsCYP81Q32) from the problematic weed Beckmannia syzigachne to test whether it conferred metabolic resistance to the acetolactate synthase-inhibiting herbicides mesosulfuron-methyl, bispyribac-sodium, and pyriminobac-methyl. Transgenic rice overexpressing BsCYP81Q32 was resistant to the three herbicides. Equally, rice overexpressing the rice ortholog gene OsCYP81Q32 was more resistant to mesosulfuron-methyl. Conversely, an OsCYP81Q32 gene knockout generated using CRISPR/Cas9 enhanced mesosulfuron-methyl sensitivity in rice. Overexpression of the BsCYP81Q32 gene resulted in enhanced mesosulfuron-methyl metabolism in transgenic rice seedlings via O-demethylation. The major metabolite, demethylated mesosulfuron-methyl, was chemically synthesized and displayed reduced herbicidal effect in plants. Moreover, a transcription factor (BsTGAL6) was identified and shown to bind a key region in the BsCYP81Q32 promoter for gene activation. Inhibition of BsTGAL6 expression by salicylic acid treatment in B. syzigachne plants reduced BsCYP81Q32 expression and consequently changed the whole plant response to mesosulfuron-methyl. Sequence polymorphisms in an important region of the BsTGAL6 promoter may explain the higher expression of BsTGAL6 in resistant versus susceptible B. syzigachne plants. Collectively, the present study reveals the evolution of an herbicide-metabolizing and resistance-endowing P450 and its transcription regulation in an economically important weedy plant species.


Assuntos
Acetolactato Sintase , Herbicidas , Oryza , Acetolactato Sintase/genética , Poaceae/genética , Compostos de Sulfonilureia/farmacologia , Oryza/genética , Oryza/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Herbicidas/farmacologia , Resistência a Herbicidas/genética
9.
J Virol ; 97(10): e0093823, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37792003

RESUMO

IMPORTANCE: Human norovirus (HuNoV) is highly infectious and can result in severe illnesses in the elderly and children. So far, there is no effective antiviral drug to treat HuNoV infection, and thus, the development of HuNoV vaccines is urgent. However, NoV evolves rapidly, and currently, at least 10 genogroups with numerous genotypes have been found. The genetic diversity of NoV and the lack of cross-protection between different genotypes pose challenges to the development of broadly protective vaccines. In this study, guided by structural alignment between GI.1 and GII.4 HuNoV VP1 proteins, several chimeric-type virus-like particles (VLPs) were designed through surface-exposed loop grafting. Mouse immunization studies show that two of the designed chimeric VLPs induced cross-immunity against both GI.1 and GII.4 HuNoVs. To our knowledge, this is the first designed chimeric VLPs that can induce cross-immune activities across different genogroups of HuNoV, which provides valuable strategies for the development of cross-reactive HuNoV vaccines.


Assuntos
Infecções por Caliciviridae , Epitopos , Genótipo , Norovirus , Vacinas Virais , Vírion , Animais , Humanos , Camundongos , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/prevenção & controle , Infecções por Caliciviridae/virologia , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Imunização , Norovirus/química , Norovirus/classificação , Norovirus/genética , Norovirus/imunologia , Vacinas Virais/química , Vacinas Virais/genética , Vacinas Virais/imunologia , Quimera/genética , Quimera/imunologia , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Vírion/química , Vírion/genética , Vírion/imunologia
10.
Plant Cell Environ ; 47(8): 3030-3045, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38644762

RESUMO

The polar auxin transport is required for proper plant growth and development. D6 PROTEIN KINASE (D6PK) is required for the phosphorylation of PIN-FORMED (PIN) auxin efflux carriers to regulate auxin transport, while the regulation of D6PK stabilization is still poorly understood. Here, we found that Cytosolic ABA Receptor Kinases (CARKs) redundantly interact with D6PK, and the interactions are dependent on CARKs' kinase activities. Similarly, CARK3 also could interact with paralogs of D6PK, including D6PKL1, D6PKL2, and D6PKL3. The genetic analysis shows that D6PK acts the downstream of CARKs to regulate Arabidopsis growth, including hypocotyl, leaf area, vein formation, and the length of silique. Loss-of-function of CARK3 in overexpressing GFP-D6PK plants leads to reduce the level of D6PK protein, thereby rescues plant growth. In addition, the cell-free degradation assays indicate that D6PK is degraded through 26 S proteasome pathway, while the phosphorylation by CARK3 represses this process in cells. In summary, D6PK stabilization by the CARK family is required for auxin-mediated plant growth and development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/enzimologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fosforilação , Ácidos Indolacéticos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Citosol/metabolismo , Ácido Abscísico/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas Quinases/metabolismo , Proteínas Quinases/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Plantas Geneticamente Modificadas
11.
Plant Cell ; 33(4): 1229-1251, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-33693903

RESUMO

Flowers are the core reproductive structures and key distinguishing features of angiosperms. Flower opening to expose stamens and gynoecia is important in cases where pollinators much be attracted to promote cross-pollination, which can enhance reproductive success and species preservation. The floral opening process is accompanied by the coordinated movement of various floral organs, particularly petals. However, the mechanisms underlying petal movement and flower opening are not well understood. Here, we integrated anatomical, physiological, and molecular approaches to determine the petal movement regulatory network using rose (Rosa hybrida) as a model. We found that PETAL MOVEMENT-RELATED PROTEIN1 (RhPMP1), a homeodomain transcription factor (TF) gene, is a direct target of ETHYLENE INSENSITIVE3, a TF that functions downstream of ethylene signaling. RhPMP1 expression was upregulated by ethylene and specifically activated endoreduplication of parenchyma cells on the adaxial side of the petal (ADSP) base by inducing the expression of RhAPC3b, a gene encoding the core subunit of the Anaphase-Promoting Complex. Cell expansion of the parenchyma on the ADSP base was subsequently enhanced, thus resulting in asymmetric growth of the petal base, leading to the typical epinastic movement of petals and flower opening. These findings provide insights into the pathway regulating petal movement and associated flower-opening mechanisms.�.


Assuntos
Etilenos/metabolismo , Flores/crescimento & desenvolvimento , Rosa/crescimento & desenvolvimento , Ciclopropanos/farmacologia , Etilenos/farmacologia , Flores/efeitos dos fármacos , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Células Vegetais/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Rosa/efeitos dos fármacos , Rosa/genética , Rosa/metabolismo
12.
Int Arch Allergy Immunol ; 185(2): 124-132, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37913762

RESUMO

INTRODUCTION: The incidence of allergic rhinitis (AR) is increasing year by year, and the pathogenesis is complex, in which diet may play an important role. The role of polyunsaturated fatty acids (PUFAs) in AR is still controversial. Previous studies have looked at the effects of PUFA during pregnancy, childhood, and adolescence. In this study, we aimed to determine the association between dietary intake of PUFA and AR in adults. METHODS: We used the NHANES database from 2005 to 2006 to include a total of 4,211 adult subjects. We collected dietary PUFA intake data and information on AR. Logistic regression and restricted cubic spline models were constructed to examine the association between PUFA intake and AR in adults. The t test was used to compare daily PUFA intakes in patients with and without AR. RESULTS: In the fully adjusted model (OR: 1.016; 95% CI: 1.003; 1.028), PUFA intake was positively correlated with allergic symptoms, hay fever, and AR in adults (p < 0.05). In addition, daily PUFA intake was significantly higher in people with allergic symptoms, hay fever, and AR than in people without the disease (p < 0.01). CONCLUSIONS: Our results suggest a positive association between dietary PUFA intake and AR in adults to a certain extent. Future studies on dietary PUFA dose will provide new strategies for the prevention and treatment of allergic diseases such as AR related to non-pharmaceutical interventions.


Assuntos
Rinite Alérgica Sazonal , Rinite Alérgica , Adulto , Gravidez , Feminino , Adolescente , Humanos , Criança , Estudos Transversais , Inquéritos Nutricionais , Dieta , Rinite Alérgica/epidemiologia , Ácidos Graxos Insaturados
13.
Ann Hematol ; 103(1): 163-174, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37817010

RESUMO

The present study aimed to investigate the clinical features, prognosis, and treatment of advanced-stage non-nasal type extranodal natural killer/T-cell lymphoma (ENKTCL). This real-world study retrospectively reviewed 56 newly diagnosed advanced-stage non-nasal type ENKTCL patients from two large-scale Chinese cancer centers in the last 10-15 years and screened 139 newly diagnosed advanced-stage nasal type ENKTCLs admitted during the same period for comparison. The non-nasal type ENKTCLs exhibited significantly higher Ki-67 expression levels compared to nasal type disease (P = 0.011). With a median follow-up duration of 75.03 months, the non-nasal group showed slightly inferior survival outcomes without statistically significant differences compared to the nasal group (median overall survival (OS): 14.57 vs. 21.53 months, 5-year OS: 28.0% vs. 38.5%, P = 0.120). Eastern Cooperative Oncology Group (ECOG) score ≥ 2 (hazard ratio (HR) = 2.18, P = 0.039) and lactic dehydrogenase (LDH) elevation (HR = 2.44, P = 0.012) were significantly correlated with worse OS in the non-nasal group. First-line gemcitabine-based chemotherapy regimens showed a trend toward slightly improved efficacy and survival outcomes compared to non-gemcitabine-based ones in the present cohort of non-nasal ENKTCLs (objective response rate: 91.7% vs. 63.6%, P = 0.144; complete response rate: 50.0% vs. 33.3%, P = 0.502; median progression-free survival: 10.43 vs. 3.40 months, P = 0.106; median OS: 25.13 vs. 9.30 months, P = 0.125), which requires further validation in larger sample size studies. Advanced-stage non-nasal type patients could achieve comparable prognosis with nasal cases after rational therapy. The modified nomogram-revised index (including age, ECOG score, and LDH) and modified international prognostic index (including age, ECOG score, LDH, and number of extranodal involvement) functioned effectively for prognostic stratification in non-nasal type ENKTCLs.


Assuntos
Linfoma Extranodal de Células T-NK , Linfoma de Células T , Humanos , Prognóstico , Estudos Retrospectivos , Modelos de Riscos Proporcionais , Células Matadoras Naturais/patologia , Linfoma de Células T/patologia , Linfoma Extranodal de Células T-NK/diagnóstico , Linfoma Extranodal de Células T-NK/tratamento farmacológico , Estadiamento de Neoplasias
14.
Ann Hematol ; 103(8): 3061-3069, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38805037

RESUMO

In this prospective, multicenter, Phase 2 clinical trial (NCT02987244), patients with peripheral T-cell lymphomas (PTCLs) who had responded to first-line chemotherapy with cyclophosphamide, doxorubicin or epirubicin, vincristine or vindesine, etoposide, and prednisone (Chi-CHOEP) were treated by autologous stem cell transplantation (ASCT) or with chidamide maintenance or observation. A total of 85 patients received one of the following interventions: ASCT (n = 15), chidamide maintenance (n = 44), and observation (n = 26). estimated 3 PFS and OS rates were 85.6%, 80.8%, and 49.4% (P = 0.001). The two-year OS rates were 85.6%, 80.8%, and 69.0% (P = 0.075).The ASCT and chidamide maintenance groups had significantly better progression-free survival (PFS) than the observation group (P = 0.001, and P = 0.01, respectively). The overall survival (OS) differed significantly between the chidamide maintenance group and the observation group ( P = 0.041). The multivariate and propensity score matching analyses for PFS revealed better outcomes in the subjects in the chidamide maintenance than observation groups (P = 0.02). The ASCT and chidamide maintenance groups had significant survival advantages over the observation group. In the post-remission stage of the untreated PTCL patients, single-agent chidamide maintenance demonstrated superior PFS and better OS than observation. Our findings highlight the potential benefit of chidamide in this patient subset, warranting further investigation through larger prospective trials. Clinical trial registration: clinicaltrial.gov, NCT02987244. Registered 8 December 2016, http://www.clinicaltrials.gov/ct2/show/NCT02987244 .


Assuntos
Aminopiridinas , Protocolos de Quimioterapia Combinada Antineoplásica , Benzamidas , Transplante de Células-Tronco Hematopoéticas , Linfoma de Células T Periférico , Humanos , Linfoma de Células T Periférico/terapia , Linfoma de Células T Periférico/mortalidade , Linfoma de Células T Periférico/tratamento farmacológico , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Aminopiridinas/uso terapêutico , Benzamidas/uso terapêutico , Estudos Prospectivos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , China/epidemiologia , Transplante Autólogo , Idoso , Taxa de Sobrevida , Adulto Jovem , Quimioterapia de Manutenção , Autoenxertos , Indução de Remissão , Adolescente
15.
Artigo em Inglês | MEDLINE | ID: mdl-38995188

RESUMO

A Gram-negative, ellipsoidal to short-rod-shaped, motile bacterium was isolated from Beijing's urban air. The isolate exhibited the closest kinship with Noviherbaspirillum aerium 122213-3T, exhibiting 98.4 % 16S rRNA gene sequence similarity. Phylogenetic analyses based on 16S rRNA gene sequences and genomes showed that it clustered closely with N. aerium 122213-3T, thus forming a distinct phylogenetic lineage within the genus Noviherbaspirillum. The average nucleotide identity and digital DNA-DNA hybridization values between strain I16B-00201T and N. aerium 122213-3T were 84.6 and 29.4 %, respectively. The respiratory ubiquinone was ubiquinone 8. The major fatty acids (>10 %) were summed feature 3 (C16:1ω6c/C16:1ω7c, 43.3 %), summed feature 8 (C18:1ω7c/C18:1ω6c, 15.9 %) and C12:0 (11.0 %). The polyamine profile showed putrescine as the predominant compound. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unknown lipids and unknown phosphatidylaminolipids. The phenotypic, phylogenetic and chemotaxonomic results consistently supported that strain I16B-00201T represented a novel species of the genus Noviherbaspirillum, for which the name Noviherbaspirillum album sp. nov. is proposed, with I16B-00201T (=CPCC 100848T=KCTC 52095T) designated as the type strain. Its DNA G+C content is 59.4 mol%. Pan-genome analysis indicated that some Noviherbaspirillum species possess diverse nitrogen and aromatic compound metabolism pathways, suggesting their potential value in pollutant treatment.


Assuntos
Microbiologia do Ar , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano , Ácidos Graxos , Hibridização de Ácido Nucleico , Fosfolipídeos , Filogenia , RNA Ribossômico 16S , Análise de Sequência de DNA , Ubiquinona , RNA Ribossômico 16S/genética , Pequim , DNA Bacteriano/genética , Ácidos Graxos/análise , Fosfolipídeos/análise
16.
J Org Chem ; 89(1): 313-320, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38079214

RESUMO

The copper-catalyzed enantioselective allylation reaction of N-aryl aldimines has been developed using a combination of Cu(OAc)2 and SPINOL-based phosphonamidite. This protocol significantly broadens the substrate scope, such that imines bearing various ortho-substituents on the N-aryl were converted smoothly into homoallylic amines in up to 99% yield and 98% ee. Taking advantage of the diversity of the N-aryl motif, three kinds of N-heterocyclic compounds were constructed, respectively, from the corresponding homoallylic amines in merely one step.

17.
Environ Sci Technol ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39079029

RESUMO

Wastewater discharge from wastewater treatment plants continuously pumps microplastics into rivers, yet their transport distances within these waterways remain unknown. Herein, we developed a conceptual framework by synthesizing the microplastic data from the Yangtze River Basin to evaluate its transport distances, quantifying a significant spatial dependence between large-scale wastewater discharge and riverine microplastics (p < 0.05). The presence of microplastics at a specific sampling site could be attributed to wastewater discharge within a large-scale range spanning >1000 km upstream, encompassing a substantial portion equivalent to one-third of the Yangtze River Basin. The dominance analysis indicated that the contribution of wastewater discharge in rivers with higher discharge (>100 m3/s) to riverine microplastic pollution exceeded 65% within the Yangtze River Basin. The spatial dependence framework of riverine microplastics on wastewater discharge advances our prior understanding of the prevention and control of riverine microplastics by demonstrating that such pollution is not limited to nearby environmental factors.

18.
Mol Biol Rep ; 51(1): 891, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39110355

RESUMO

BACKGROUND: Peptide transporter 1 (PepT1) transports bacterial oligopeptide products and induces inflammation of the bowel. Nutritional peptides compete for the binding of intestinal bacterial products to PepT1. We investigated the mechanism of short-peptide-based enteral nutrition (SPEN) on the damage to the gut caused by the bacterial oligopeptide product muramyl dipeptide (MDP), which is transported by PepT1. The gut-lung axis is a shared mucosal immune system, and immune responses and disorders can affect the gut-respiratory relationship. METHODS AND RESULTS: Sprague-Dawley rats were gavaged with solutions containing MDP, MDP + SPEN, MDP + intact-protein-based enteral nutrition (IPEN), glucose as a control, or glucose with GSK669 (a NOD2 antagonist). Inflammation, mitochondrial damage, autophagy, and apoptosis were explored to determine the role of the PepT1-nucleotide-binding oligomerization domain-containing protein 2 (NOD2)-beclin-1 signaling pathway in the small intestinal mucosa. MDP and proinflammatory factors of lung tissue were explored to determine that MDP can migrate to lung tissue and cause inflammation. Induction of proinflammatory cell accumulation and intestinal damage in MDP gavage rats was associated with increased NOD2 and Beclin-1 mRNA expression. IL-6 and TNF-α expression and apoptosis were increased, and mitochondrial damage was severe, as indicated by increased mtDNA in the MDP group compared with controls. MDP levels and expression of proinflammatory factors in lung tissue increased in the MDP group compared with the control group. SPEN, but not IPEN, eliminated these impacts. CONCLUSIONS: Gavage of MDP to rats resulted in damage to the gut-lung axis. SPEN reverses the adverse effects of MDP. The PepT1-NOD2-beclin-1 pathway plays a role in small intestinal inflammation, mitochondrial damage, autophagy, and apoptosis.


Assuntos
Acetilmuramil-Alanil-Isoglutamina , Proteína Beclina-1 , Nutrição Enteral , Lesão Pulmonar , Proteína Adaptadora de Sinalização NOD2 , Transportador 1 de Peptídeos , Ratos Sprague-Dawley , Transdução de Sinais , Animais , Transportador 1 de Peptídeos/metabolismo , Transportador 1 de Peptídeos/genética , Ratos , Proteína Beclina-1/metabolismo , Proteína Beclina-1/genética , Proteína Adaptadora de Sinalização NOD2/metabolismo , Proteína Adaptadora de Sinalização NOD2/genética , Transdução de Sinais/efeitos dos fármacos , Lesão Pulmonar/metabolismo , Masculino , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Nutrição Enteral/métodos , Apoptose/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Autofagia/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Pulmão/efeitos dos fármacos , Inflamação/metabolismo
19.
Future Oncol ; 20(5): 245-256, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38018460

RESUMO

Low-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type has a favorable outcome with radiation therapy alone, and the addition of chemotherapy shows no survival benefit. Nonetheless, a proportion of patients will relapse or progress, with a dismal outcome, highlighting the need for a novel therapeutic strategy. Promising preliminary findings indicate the efficacy of PD-1/PD-L1 inhibitors in extranodal natural killer/T-cell lymphoma, nasal type, with good toxicity profiles. Here we describe the design of a phase II study (CLCG-NKT-2101), which is evaluating the safety and efficacy of adding anti-PD-1 antibody to the current radiation therapy regimen in low-risk early-stage extranodal natural killer/T-cell lymphoma, nasal type patients. Tislelizumab will be added in an inductive and concurrent way to radiation therapy. The primary end point will be the complete response rate after induction immunotherapy. Clinical trial registration: ClinicalTrials.gov (NCT05149170).


Assuntos
Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica , Linfoma de Células T , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Estadiamento de Neoplasias , Linfoma de Células T/etiologia , Células Matadoras Naturais , Ensaios Clínicos Fase II como Assunto
20.
Bioorg Chem ; 149: 107531, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38850779

RESUMO

Nitroreductase (NTR) overexpression often occurs in tumors, highlighting the significance of effective NTR detection. Despite the utilization of various optical methods for this purpose, the absence of an efficient tumor-targeting optical probe for NTR detection remains a challenge. In this research, a novel tumor-targeting probe (Cy-Bio-NO2) is developed to perform dual-modal NTR detection using near-infrared fluorescence and photoacoustic techniques. This probe exhibits exceptional sensitivity and selectivity to NTR. Upon the reaction with NTR, Cy-Bio-NO2 demonstrates a distinct fluorescence "off-on" response at 800 nm, with an impressive detection limit of 12 ng/mL. Furthermore, the probe shows on-off photoacoustic signal with NTR. Cy-Bio-NO2 has been successfully employed for dual-modal NTR detection in living cells, specifically targeting biotin receptor-positive cancer cells for imaging purposes. Notably, this probe effectively detects tumor hypoxia through dual-modal imaging in tumor-bearing mice. The strategy of biotin incorporation markedly enhances the probe's tumor-targeting capability, facilitating its engagement in dual-modal imaging at tumor sites. This imaging capacity holds substantial promise as an accurate tool for cancer diagnosis.


Assuntos
Corantes Fluorescentes , Nitrorredutases , Imagem Óptica , Animais , Humanos , Camundongos , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Neoplasias/diagnóstico por imagem , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/metabolismo , Nitrorredutases/metabolismo , Nitrorredutases/análise , Técnicas Fotoacústicas , Dióxido de Nitrogênio/síntese química , Dióxido de Nitrogênio/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA