Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 123
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 120(14): e2300439120, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36996102

RESUMO

Ongoing host-pathogen interactions can trigger a coevolutionary arms race, while genetic diversity within the host can facilitate its adaptation to pathogens. Here, we used the diamondback moth (Plutella xylostella) and its pathogen Bacillus thuringiensis (Bt) as a model for exploring an adaptive evolutionary mechanism. We found that insect host adaptation to the primary Bt virulence factors was tightly associated with a short interspersed nuclear element (SINE - named SE2) insertion into the promoter of the transcriptionally activated MAP4K4 gene. This retrotransposon insertion coopts and potentiates the effect of the transcription factor forkhead box O (FOXO) in inducing a hormone-modulated Mitogen-activated protein kinase (MAPK) signaling cascade, leading to an enhancement of a host defense mechanism against the pathogen. This work demonstrates that reconstructing a cis-trans interaction can escalate a host response mechanism into a more stringent resistance phenotype to resist pathogen infection, providing a new insight into the coevolutionary mechanism of host organisms and their microbial pathogens.


Assuntos
Bacillus thuringiensis , Mariposas , Animais , Endotoxinas/farmacologia , Retroelementos/genética , Mariposas/metabolismo , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis/metabolismo , Resistência a Inseticidas/genética , Larva/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas Hemolisinas/metabolismo
2.
BMC Med Imaging ; 24(1): 56, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38443817

RESUMO

BACKGROUND: This study aimed to establish a dedicated deep-learning model (DLM) on routine magnetic resonance imaging (MRI) data to investigate DLM performance in automated detection and segmentation of meningiomas in comparison to manual segmentations. Another purpose of our work was to develop a radiomics model based on the radiomics features extracted from automatic segmentation to differentiate low- and high-grade meningiomas before surgery. MATERIALS: A total of 326 patients with pathologically confirmed meningiomas were enrolled. Samples were randomly split with a 6:2:2 ratio to the training set, validation set, and test set. Volumetric regions of interest (VOIs) were manually drawn on each slice using the ITK-SNAP software. An automatic segmentation model based on SegResNet was developed for the meningioma segmentation. Segmentation performance was evaluated by dice coefficient and 95% Hausdorff distance. Intra class correlation (ICC) analysis was applied to assess the agreement between radiomic features from manual and automatic segmentations. Radiomics features derived from automatic segmentation were extracted by pyradiomics. After feature selection, a model for meningiomas grading was built. RESULTS: The DLM detected meningiomas in all cases. For automatic segmentation, the mean dice coefficient and 95% Hausdorff distance were 0.881 (95% CI: 0.851-0.981) and 2.016 (95% CI:1.439-3.158) in the test set, respectively. Features extracted on manual and automatic segmentation are comparable: the average ICC value was 0.804 (range, 0.636-0.933). Features extracted on manual and automatic segmentation are comparable: the average ICC value was 0.804 (range, 0.636-0.933). For meningioma classification, the radiomics model based on automatic segmentation performed well in grading meningiomas, yielding a sensitivity, specificity, accuracy, and area under the curve (AUC) of 0.778 (95% CI: 0.701-0.856), 0.860 (95% CI: 0.722-0.908), 0.848 (95% CI: 0.715-0.903) and 0.842 (95% CI: 0.807-0.895) in the test set, respectively. CONCLUSIONS: The DLM yielded favorable automated detection and segmentation of meningioma and can help deploy radiomics for preoperative meningioma differentiation in clinical practice.


Assuntos
Aprendizado Profundo , Neoplasias Meníngeas , Meningioma , Humanos , Meningioma/diagnóstico por imagem , Meningioma/cirurgia , Radiômica , Imageamento por Ressonância Magnética , Neoplasias Meníngeas/diagnóstico por imagem , Neoplasias Meníngeas/cirurgia
3.
Proc Natl Acad Sci U S A ; 118(25)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34131077

RESUMO

Permafrost degradation may induce soil carbon (C) loss, critical for global C cycling, and be mediated by microbes. Despite larger C stored within the active layer of permafrost regions, which are more affected by warming, and the critical roles of Qinghai-Tibet Plateau in C cycling, most previous studies focused on the permafrost layer and in high-latitude areas. We demonstrate in situ that permafrost degradation alters the diversity and potentially decreases the stability of active layer microbial communities. These changes are associated with soil C loss and potentially a positive C feedback. This study provides insights into microbial-mediated mechanisms responsible for C loss within the active layer in degraded permafrost, aiding in the modeling of C emission under future scenarios.


Assuntos
Carbono/análise , Microbiologia Ambiental , Pergelissolo , Biodiversidade , China , Microbiota , Compostos Orgânicos/análise , Plantas , Solo/química
4.
J Asian Nat Prod Res ; : 1-9, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38900048

RESUMO

A new coumarin (1) and a new flavonoid (2) were isolated from the air-dried flower buds of Ochrocarpus longifolius, together with ten known compounds (3-12). The structures of two new compounds were established by 1D and 2D NMR and MS data. In addition, the new compound 2 showed significant proliferation inhibitory activity on Eca-109 and MGC-803 cells. The results of this study may enrich the diversity of compounds from O. longifolius and provide a basis for further research on its natural products and pharmacological activities.

5.
Zhongguo Zhong Yao Za Zhi ; 49(6): 1421-1428, 2024 Mar.
Artigo em Zh | MEDLINE | ID: mdl-38621925

RESUMO

To investigate the mechanism of action of aqueous extract of Strychni Semen(SA) on bone destruction in rats with type Ⅱ collagen-induced arthritis(CIA), the SD rats were randomly divided into normal group, model group, low, medium, and high dose(2.85, 5.70, and 11.40 mg·kg~(-1)) groups of SA, and methotrexate group. Except for the normal group, the CIA model was prepared for the other groups. After the second immunization, different doses of SA were given to the low, medium, and high dose groups of SA once a day, and the methotrexate group was given once every three days. 0.3% sodium hydroxymethylcellulose(CMC-Na) was given once a day to the normal and model groups for 28 d. The clinical score of arthritis was evaluated every three days. Micro computed tomography(Micro-CT) method was used to evaluate the degree of bone destruction. Histopathological changes in the joint tissue and the number of osteoclasts in CIA rats were evaluated by hematoxylin-eosin(HE) staining and tartrate-resistant acid phosphatase(TRAP) staining. The expression of interleukin-1ß(IL-1ß) in the joint tissue of rats was detected by immunohistochemistry. Western blot was used to detect key protein expression in mitogen-activated protein kinase(MAPK) and phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt) signaling pathways in the joint tissue of rats. The results showed that different doses of SA were able to improve the red and swollen inflammatory joint and joint deformity in CIA rats to varying degrees, reduce the clinical score, inhibit synovial inflammation, vascular opacification, cartilage erosion, and bone destruction, and reduce the number of TRAP-positive cells in bone tissue. Micro-CT results showed that the SA was able to increase bone mineral density, bone volume fraction, trabecular reduce, and trabecular number and reduce bone surface/bone volume and trabecular separation/spacing. Different doses of SA could down-regulate the protein expression of IL-1ß, p-JNK, p-ERK, p-p38, PI3K, and p-Akt to varying degrees. In conclusion, SA can improve disease severity, attenuate histopathological and imaging changes in joints, and have osteoprotective effects in CIA rats, and its mechanism of action may be related to the inhibition of the overactivation of MAPK and PI3K/Akt signaling pathways.


Assuntos
Artrite Experimental , Artrite Reumatoide , Ratos , Animais , Colágeno Tipo II , Metotrexato , Proteínas Proto-Oncogênicas c-akt , Sêmen , Microtomografia por Raio-X , Fosfatidilinositol 3-Quinases , Ratos Sprague-Dawley , Artrite Reumatoide/tratamento farmacológico , Artrite Experimental/tratamento farmacológico , Artrite Experimental/induzido quimicamente
6.
Zhongguo Zhong Yao Za Zhi ; 49(6): 1429-1437, 2024 Mar.
Artigo em Zh | MEDLINE | ID: mdl-38621926

RESUMO

This study aims to explore the mechanism of aqueous extract of Strychni Semen(SA) in relieving pain in the rat model of rheumatoid arthritis(RA) via Toll-like receptor 4(TLR4)/tumor necrosis factor-α(TNF-α)/matrix metalloproteinase-9(MMP-9) signaling pathway. Firstly, the main chemical components of Strychni Semen were searched against TCMSP, TCMID, ETCM, and related literature, and the main targets of the chemical components were retrieved from TargetNet and SwissTargetPrediction. The main targets of RA and pain were searched against GeneCards, Online Mendelian Inheritance in Man(OMIM), and Therapeutic Target Database(TTD). Venny 2.1.0 was used to obtain the common targets shared by Strychni Semen, RA, and pain, and STRING and Cytoscape 3.6.1 were used to build the protein-protein interaction network. Then, molecular docking was carried out in AutoDock Vina. Finally, the rat model of type Ⅱ collagen-induced arthritis(CIA) was established. The up-down method and acetone method were employed to examine the mechanical pain threshold and cold pain threshold of rats, and the pain-relieving effect of SA on CIA rats was evaluated comprehensively. Hematoxylin-eosin(HE) staining was employed to evaluate the histopathological changes of joints in CIA rats. The expression levels of key target proteins was determined by immunohistochemistry and Western blot, and the mRNA levels of key targets were determined by real-time fluorescence quantitative polymerase chain reaction(real-time PCR). The results of network prediction showed that Strychni Semen may act on the TLR4/TNF-α/MMP-9 signaling pathway to exert the pain-relieving effect. The results of molecular docking showed that brucine, the main active component of SA, had strong binding ability to TLR4, TNF-α, and MMP-9. The results of animal experiments showed that SA improved the mechanical and cold pain sensitivity(P<0.05, P<0.01) and reduced the joint histopathological score of CIA rats(P<0.01). In addition, medium and high doses of SA down-regulated the protein and mRNA levels of TNF-α, TLR4, and MMP-9(P<0.05,P<0.01). In conclusion, SA alleviated the mechanical pain sensitivity, cold pain sensitivity, and joint histopathological changes in CIA rats by inhibiting the over activation of TLR4/TNF-α/MMP-9 signaling pathway.


Assuntos
Artrite Reumatoide , Fator de Necrose Tumoral alfa , Humanos , Ratos , Animais , Fator de Necrose Tumoral alfa/genética , Metaloproteinase 9 da Matriz/genética , Sêmen , Simulação de Acoplamento Molecular , Receptor 4 Toll-Like/genética , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/genética , Transdução de Sinais , Dor/tratamento farmacológico , RNA Mensageiro
7.
PLoS Pathog ; 17(9): e1009917, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34495986

RESUMO

Host-pathogen interactions are central components of ecological networks where the MAPK signaling pathways act as central hubs of these complex interactions. We have previously shown that an insect hormone modulated MAPK signaling cascade participates as a general switch to trans-regulate differential expression of diverse midgut genes in the diamondback moth, Plutella xylostella (L.) to cope with the insecticidal action of Cry1Ac toxin, produced by the entomopathogenic bacterium Bacillus thuringiensis (Bt). The relationship between topology and functions of this four-tiered phosphorylation signaling cascade, however, is an uncharted territory. Here, we carried out a genome-wide characterization of all the MAPK orthologs in P. xylostella to define their phylogenetic relationships and to confirm their evolutionary conserved modules. Results from quantitative phosphoproteomic analyses, combined with functional validations studies using specific inhibitors and dsRNAs lead us to establish a MAPK "road map", where p38 and ERK MAPK signaling pathways, in large part, mount a resistance response against Bt toxins through regulating the differential expression of multiple Cry toxin receptors and their non-receptor paralogs in P. xylostella midgut. These data not only advance our understanding of host-pathogen interactions in agricultural pests, but also inform the future development of biopesticides that could suppress Cry resistance phenotypes.


Assuntos
Infecções por Bactérias Gram-Positivas/metabolismo , Interações Hospedeiro-Patógeno/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Mariposas/metabolismo , Mariposas/microbiologia , Animais , Bacillus thuringiensis , Toxinas de Bacillus thuringiensis/metabolismo , Endotoxinas/metabolismo , Infecções por Bactérias Gram-Positivas/veterinária , Proteínas Hemolisinas/metabolismo , Resistência a Inseticidas
8.
Chemistry ; 29(44): e202301310, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37477115

RESUMO

A novel triazine-based covalent organic framework (TFPT-Bz COF) has been constructed by the condensation of 2,4,6-tris(5-formyl-2-pyridinoxy)-1,3,5-triazine (TFPT) and benzidine (BZ) with deep eutectic solvent (DES) as the reaction medium. After the introduction of Pd ions through strong coordination to TFPT-Bz COF matrix, the constructed TFPT-Bz COF/Pd composite exhibited excellent catalytic activity for C-H arylation of azoles with aryl halides in 2-methyltetrahydrofuran. The protocol allows the arylation of a variety of substituted azoles with diverse aryl halides in high to excellent yield. Moreover, the TFPT-Bz COF/Pd catalyst can be recycled several times without significantly reducing its activity.

9.
BMC Cancer ; 22(1): 1031, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183074

RESUMO

BACKGROUND: Both Response Evaluation Criteria in Solid Tumors (RECIST) and tumor regression grade (TRG) play key roles in evaluating tumor response. We analyzed the consistency of TRG and RECIST 1.1 for gastric cancer (GC) patients and compared their prognostic values. METHODS: Patients with GC who received preoperative chemotherapy or chemoimmunotherapy and had records of TRG from December 2013 to October 2021 were enrolled retrospectively. TRG 0-1 and 2-3 are considered as corresponding to complete response (CR)/partial response (PR) and stable disease (SD)/progress disease (PD) in RECIST 1.1, respectively. The primary endpoints were disease-free survival (DFS) and overall survival (OS). The consistency of RECIST and TRG was examined by kappa statistics. Survival analysis was performed using the Kaplan Meier method. RESULT: One hundred fifty seven GC patients were enrolled, including 125 with preoperative chemotherapy and 32 with chemoimmunotherapy. Among them, 56 patients had measurable lesions. Only 19.6% (11/56) of the patients had consistent results between RECIST 1.1 and TRG. TRG was correlated with both OS and DFS (P = 0.02 and 0.03, respectively) while response according to RECIST1.1 was not (P = 0.86 and 0.23, respectively). The median DFS had not reached in the TRG 0-1 group and was 16.13 months in TRG 2-3 group. TRG 2-3 was associated with young age and peritoneal or liver metastasis. Besides, preoperative chemoimmunotherapy had a significantly higher pCR rate than chemotherapy alone (34.4% vs 8.0%, P < 0.001). CONCLUSION: TRG was in poor agreement with RECIST 1.1. TRG was better than RECIST 1.1 in predicting DFS and OS for GC patients who received preoperative therapy.


Assuntos
Neoplasias Gástricas , Intervalo Livre de Doença , Humanos , Terapia Neoadjuvante/métodos , Critérios de Avaliação de Resposta em Tumores Sólidos , Estudos Retrospectivos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/cirurgia , Resultado do Tratamento
10.
Psychol Med ; 52(14): 3193-3201, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-33588966

RESUMO

BACKGROUND: Network approach has been applied to a wide variety of psychiatric disorders. The aim of the present study was to identify network structures of remitters and non-remitters in patients with first-episode psychosis (FEP) at baseline and the 6-month follow-up. METHODS: Participants (n = 252) from the Korean Early Psychosis Study (KEPS) were enrolled. They were classified as remitters or non-remitters using Andreasen's criteria. We estimated network structure with 10 symptoms (three symptoms from the Positive and Negative Syndrome Scale, one depressive symptom, and six symptoms related to schema and rumination) as nodes using a Gaussian graphical model. Global and local network metrics were compared within and between the networks over time. RESULTS: Global network metrics did not differ between the remitters and non-remitters at baseline or 6 months. However, the network structure and nodal strengths associated with positive-self and positive-others scores changed significantly in the remitters over time. Unique central symptoms for remitters and non-remitters were cognitive brooding and negative-self, respectively. The correlation stability coefficients for nodal strength were within the acceptable range. CONCLUSION: Our findings indicate that network structure and some nodal strengths were more flexible in remitters. Negative-self could be an important target for therapeutic intervention.


Assuntos
Transtornos Psicóticos , Humanos , Transtornos Psicóticos/psicologia , Escalas de Graduação Psiquiátrica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA