Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 42
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Arch Biochem Biophys ; 758: 110051, 2024 08.
Artigo em Inglês | MEDLINE | ID: mdl-38851368

RESUMO

Colorectal cancer (CRC) is an aggressive cancer type globally. Surgery and chemotherapy are often ineffective at curing CRC. Dictamnine is a natural product derived from Dictamnus dasycarpus Turcz. root bark and possesses multi-pharmacological properties, including anticancer effects. Nevertheless, the biological roles and the possible mechanism of dictamnine in CRC are still unclear. Here, we demonstrated that dictamnine blocked cell viability and proliferation in DLD-1 human colorectal adenocarcinoma cells and LoVo human colon cancer cells. Dictamnine triggered CRC cell ferroptosis, as evidenced by enhanced levels of reactive oxygen species, malondialdehyde, and Fe2+ levels, alongside downregulation of glutathione peroxidase 4 protein expression. In addition, CD163 (HPA ID: HPA046404) was highly expressed and CD68 (HPA ID: CAB000051) was lowly expressed in CRC tissues and CRC cell culture medium-cultured THP-1 monocytes-derived macrophages. The patients with CD163 low-expression lived much longer than those with CD163 high-expression, indicating that M2 polarization of macrophages was related to poor prognosis of CRC. Dictamnine markedly inhibited CD163 protein expression, transforming growth factor-ß and arginase 1 mRNA expressions and IL-10 production in macrophages with CRC cell co-culture, suggesting that dictamnine impeded M2 polarization of macrophages. Mechanistically, dictamnine repressed ERK phosphorylation in CRC cells. The treatment with the ERK activator tBHQ counteracted the effects of dictamnine on CRC cell proliferation and ferroptosis, as well as its inhibitory effect on M2 polarization of macrophages. Results of a xenograft model showed that dictamnine effectively hindered CRC tumor growth in vivo. Collectively, these data provide evidence for the clinical trials of dictamnine as a novel drug for CRC therapy.


Assuntos
Neoplasias Colorretais , Ferroptose , Sistema de Sinalização das MAP Quinases , Macrófagos , Ferroptose/efeitos dos fármacos , Humanos , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Neoplasias Colorretais/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Animais , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química , Camundongos Nus , Camundongos Endogâmicos BALB C , Masculino
2.
J Biochem Mol Toxicol ; 38(7): e23762, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38967723

RESUMO

Given the malignancy of gastric cancer, developing highly effective and low-toxic targeted drugs is essential to prolong patient survival and improve patient outcomes. In this study, we conducted structural optimizations based on the benzimidazole scaffold. Notably, compound 8 f presented the most potent antiproliferative activity in MGC803 cells and induced cell cycle arrest at the G0/G1 phase. Further mechanistic studies demonstrated that compound 8 f caused the apoptosis of MGC803 cells by elevating intracellular reactive oxygen species (ROS) levels and activating the mitogen-activated protein kinase (MAPK) signaling pathway, accompanied by corresponding markers change. In vivo investigations additionally validated the inhibitory effect of compound 8 f on tumor growth in xenograft models bearing MGC803 cells without obvious toxicity. Our studies suggest that compound 8 f holds promise as a potential and safe lead compound for developing anti-gastric cancer agents.


Assuntos
Antineoplásicos , Benzimidazóis , Sistema de Sinalização das MAP Quinases , Neoplasias Gástricas , Animais , Humanos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Benzimidazóis/farmacologia , Benzimidazóis/química , Linhagem Celular Tumoral , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos Nus , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Neoplasias Gástricas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Biomed Eng Online ; 23(1): 84, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39175006

RESUMO

This study aims to develop a super-resolution (SR) algorithm tailored specifically for enhancing the image quality and resolution of early cervical cancer (CC) magnetic resonance imaging (MRI) images. The proposed method is subjected to both qualitative and quantitative analyses, thoroughly investigating its performance across various upscaling factors and assessing its impact on medical image segmentation tasks. The innovative SR algorithm employed for reconstructing early CC MRI images integrates complex architectures and deep convolutional kernels. Training is conducted on matched pairs of input images through a multi-input model. The research findings highlight the significant advantages of the proposed SR method on two distinct datasets at different upscaling factors. Specifically, at a 2× upscaling factor, the sagittal test set outperforms the state-of-the-art methods in the PSNR index evaluation, second only to the hybrid attention transformer, while the axial test set outperforms the state-of-the-art methods in both PSNR and SSIM index evaluation. At a 4× upscaling factor, both the sagittal test set and the axial test set achieve the best results in the evaluation of PNSR and SSIM indicators. This method not only effectively enhances image quality, but also exhibits superior performance in medical segmentation tasks, thereby providing a more reliable foundation for clinical diagnosis and image analysis.


Assuntos
Aprendizado Profundo , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Neoplasias do Colo do Útero , Neoplasias do Colo do Útero/diagnóstico por imagem , Humanos , Feminino , Processamento de Imagem Assistida por Computador/métodos , Algoritmos
4.
Biomed Eng Online ; 22(1): 103, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37907955

RESUMO

To classify early endometrial cancer (EC) on sagittal T2-weighted images (T2WI) by determining the depth of myometrial infiltration (MI) using a computer-aided diagnosis (CAD) method based on a multi-stage deep learning (DL) model. This study retrospectively investigated 154 patients with pathologically proven early EC at the institution between January 1, 2018, and December 31, 2020. Of these patients, 75 were in the International Federation of Gynecology and Obstetrics (FIGO) stage IA and 79 were in FIGO stage IB. An SSD-based detection model and an Attention U-net-based segmentation model were trained to select, crop, and segment magnetic resonance imaging (MRl) images. Then, an ellipse fitting algorithm was used to generate a uterine cavity line (UCL) to obtain MI depth for classification. In the independent test datasets, the uterus and tumor detection model achieves an average precision rate of 98.70% and 87.93%, respectively. Selecting the optimal MRI slices method yields an accuracy of 97.83%. The uterus and tumor segmentation model with mean IOU of 0.738 and 0.655, mean PA of 0.867 and 0.749, and mean DSC of 0.845 and 0.779, respectively. Finally, the CAD method based on the calculated MI depth reaches an accuracy of 86.9%, a sensitivity of 81.8%, and a specificity of 91.7% for early EC classification. In this study, the CAD method implements an end-to-end early EC classification and is found to be on par with radiologists in terms of performance. It is more intuitive and interpretable than previous DL-based CAD methods.


Assuntos
Neoplasias do Endométrio , Imageamento por Ressonância Magnética , Feminino , Humanos , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Neoplasias do Endométrio/diagnóstico por imagem , Neoplasias do Endométrio/patologia , Diagnóstico por Computador , Computadores
5.
J Opt Soc Am A Opt Image Sci Vis ; 40(11): 2068-2077, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38038073

RESUMO

Optical coherence tomography (OCT) is a noninvasive optical imaging technique that can be used to produce three-dimensional images of fingerprints. However, the low quality and poor resolution of the regions of interest (ROIs) in OCT images make it challenging to segment small tissues accurately. To address this issue, a super-resolution (SR) network called ESRNet has been developed to enhance the quality of OCT images, facilitating their applications in research. Firstly, the performance of the SR images produced by ESRNet is evaluated by comparing it to those generated by five other SR methods. Specifically, the SR performance is evaluated using three upscale factors (2×, 3×, and 4×) to assess the quality of the enhanced images. Based on the results obtained from the three datasets, it is evident that ESRNet outperforms current advanced networks in terms of SR performance. Furthermore, the segmentation accuracy of sweat glands has been significantly improved by the SR images. The number of sweat glands in the top view increased from 102 to 117, further substantiating the performance of the ESRNet network. The spiral structure of sweat glands is clear to human eyes and has been verified by showing similar left-right-handed spiral numbers. Finally, a sweat gland recognition method for the SR 3D images is proposed.


Assuntos
Glândulas Sudoríparas , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Glândulas Sudoríparas/diagnóstico por imagem , Imageamento Tridimensional , Algoritmos , Olho
6.
Environ Geochem Health ; 45(7): 4703-4717, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36905567

RESUMO

Groundwater is susceptible to arsenic contamination by sediment with high arsenic content, which is the primary culprit of regional arsenic pollution and poisoning. To explore the influence of the change in hydrodynamic conditions caused by changes in the sedimentary environment over time on arsenic content in sediments during the Quaternary, the hydrodynamic characteristics and arsenic content enrichment of borehole sediments were studied in typical high-arsenic groundwater areas of the Jianghan-Dongting Basin, China. The regional hydrodynamic conditions represented by each borehole location were analyzed, the correlation between the variation in groundwater dynamics characteristics and arsenic content in different hydrodynamic periods was analyzed, and the relationship between arsenic content and grain size distribution was quantitatively investigated using grain size parameter calculation, elemental analysis, and statistical estimates of arsenic content in borehole sediments. We observed that the relationship between arsenic content and hydrodynamic conditions differed between sedimentary periods. Furthermore, arsenic content in the sediments from the borehole at Xinfei Village was significantly and positively correlated with a grain size of 127.0-240.0 µm. For the borehole at Wuai Village, arsenic content was significantly and positively correlated with a grain size of 1.38-9.82 µm size (at 0.05 level of significance). However, arsenic content was inversely correlated with grain sizes of 110.99-716.87 and 133.75-282.07 µm at p values of 0.05 and 0.01, respectively. For the borehole at Fuxing Water Works, arsenic content was significantly and positively correlated with a grain size of 409.6-655.0 µm size (at 0.05 level of significance). Arsenic tended to be enriched in transitional and turbidity facies sediments with normal corresponding hydrodynamic strength but poor sorting. Furthermore, continuous and stable sedimentary sequences were conducive to arsenic enrichment. Fine-grain sediments provided abundant potential adsorption sites for high-arsenic sediments, but finer particle size was not correlated with higher arsenic levels.


Assuntos
Arsênio , Água Subterrânea , Poluentes Químicos da Água , Arsênio/análise , Hidrodinâmica , Sedimentos Geológicos/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Água Subterrânea/análise
7.
Insect Mol Biol ; 31(3): 377-390, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35141960

RESUMO

Laodelphax striatellus is a sap-feeding pest and the main insect vector of rice stripe virus (RSV). There is an urgent need to identify molecular targets to control this insect pest and plant arboviruses. In this study, we identified a L. striatellus gene (named LsGrpE) encoding a GroP-E-like protein. We found that the LsGrpE protein localized to mitochondria. Using gene-specific dsRNA to interfere with the expression of LsGrpE led to a significant increase in insect mortality, and most of the surviving insects could not develop into adults. Further analyses revealed that LsGrpE deficiency caused mitochondrial dysfunction and inhibited the insulin pathway, resulting in diabetes-like symptoms such as elevated blood sugar, inactive behaviour, developmental delay, and death. In addition, LsGrpE deficiency significantly reduced the RSV titre in surviving L. striatellus, and indirectly prevented viral vertical transmission by reducing the number of adults. We generated transgenic rice plants expressing LsGrpE-specific dsRNA, and the dsRNA was acquired by L. striatellus during feeding, resulting in increased insect mortality and the prevention of arboviral transmission. This study clarifies the function of LsGrpE and demonstrates that LsGrpE can be used as a molecular target of plant-generated dsRNA to resist this sap-feeding pest, a17nd therefore, its transmitted arboviruses.


Assuntos
Arbovírus , Hemípteros , Oryza , Tenuivirus , Animais , Arbovírus/genética , Arbovírus/metabolismo , Hemípteros/genética , Hemípteros/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Insetos/genética , Mitocôndrias/genética , Oryza/genética , Interferência de RNA , RNA de Cadeia Dupla/metabolismo , Tenuivirus/genética
8.
PLoS Pathog ; 14(2): e1006909, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29474489

RESUMO

Insect vitellogenin (Vg) has been considered to be synthesized in the fat body. Here, we found that abundant Vg protein is synthesized in Laodelphax striatellus hemocytes as well. We also determined that only the hemocyte-produced Vg binds to Rice stripe virus (RSV) in vivo. Examination of the subunit composition of L. striatellus Vg (LsVg) revealed that LsVg was processed differently after its expression in different tissues. The LsVg subunit able to bind to RSV exist stably only in hemocytes, while fat body-produced LsVg lacks the RSV-interacting subunit. Nymph and male L. striatellus individuals also synthesize Vg but only in hemocytes, and the proteins co-localize with RSV. We observed that knockdown of LsVg transcripts by RNA interference decreased the RSV titer in the hemolymph, and thus interfered with systemic virus infection. Our results reveal the sex-independent expression and tissue-specific processing of LsVg and also unprecedentedly connect the function of this protein in mediating virus transmission to its particular molecular forms existing in tissues previously known as non-Vg producing.


Assuntos
Proteínas de Insetos/fisiologia , Insetos/virologia , Doenças das Plantas/virologia , Vírus de Plantas/fisiologia , Viroses/transmissão , Vitelogeninas/fisiologia , Animais , Hemípteros/virologia , Insetos/metabolismo , Masculino , Ninfa , Especificidade de Órgãos , Oryza/virologia , Vírus de Plantas/patogenicidade , Tenuivirus/fisiologia , Viroses/metabolismo , Vitelogeninas/metabolismo
9.
Bioorg Chem ; 103: 104161, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32889380

RESUMO

Capsaicinoids are plant secondary metabolites, and capsaicin is the main principal that responsible to the pungency of chili peppers, with widely application as food additive. In our study, capsaicin was characterized as lysine specific demethylase 1A (KDM1A/LSD1) inhibitor with IC50 of 0.6 ± 0.0421 µM in biochemical level, and can bind KDM1A recombinant directly and reversibly. Further cellular study confirmed that capsaicin can bind and inhibit KDM1A in gastric cancer cell line BGC-823 and further inhibit cell invasion and migration by reversing epithelial-mesenchymal transition (EMT). In sum, our findings identified KDM1A as a target of capsaicin and reveals capsaicin as a modifier of histone methylation for the first time, which may provide a new skeleton for further optimization of KDM1A inhibitor.


Assuntos
Capsaicina/uso terapêutico , Histona Desmetilases/antagonistas & inibidores , Capsaicina/farmacologia , Humanos , Estrutura Molecular , Relação Estrutura-Atividade
10.
Carcinogenesis ; 39(7): 889-899, 2018 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-29757351

RESUMO

Chronic gut inflammation disposes to an increased risk of colitis-associated cancer. Chemoprevention is an attractive complementary strategy. We aimed to evaluate the chemopreventive effects of M10, a novel derivative of Myricetin, in the murine azoxymethane/dextran sodium sulfate model. Oral administration of M10 at 50-100 mg/kg once a day for consecutive 12 weeks significantly prevented ulcerative colitis (UC) and colorectal tumor. Pathological analysis of intestines showed that M10 reduced the degree of chronic inflammation and prevented the progression of colorectal tumorigenesis. Flow cytometry analysis of the immunocytes isolated from intraepithelial and lamina propria showed that M10 prevented the infiltration of myeloid-derived suppressor cells and increased CD8+T and CD4+T cells in colorectal tissues. Enzyme-linked immunosorbent analysis revealed the reduction of pro-inflammatory mediators granulocyte-macrophage colony-stimulating factor/macrophage colony-stimulating factor, IL-6 and TNF-α in colonic mucosa. Western blot assay also showed M10 prevention of the NF-κB/IL-6/STAT3 pathways and the biomarkers of inflammation and colorectal tumorigenesis. Electron microscopy analysis revealed that M10 prevent robust endoplasmic reticulum (ER) stress-induced autophagy in inflamed colonic mucosal cells. In conclusion, oral administration of Myricetin derivative M10 exerts chemoprevention of UC and colorectal tumor in mice. The mechanism of chemoprevention is associated with the reduction of biomarkers of chronic inflammation and proliferation through attenuating robust ER stress in inflamed colonic mucosal cells. M10 exerts chemoprevention activity without evidence of toxicity in mice. These results justify further evaluation of M10 in clinical trials. M10 could develop a promising regimen in the chemoprevention of colitis and colorectal cancer.


Assuntos
Alanina/análogos & derivados , Colite Ulcerativa/prevenção & controle , Neoplasias Colorretais/prevenção & controle , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Flavonoides/farmacologia , Hidroxiquinolinas/farmacologia , Alanina/farmacologia , Animais , Anticarcinógenos/farmacologia , Colo/efeitos dos fármacos , Colo/metabolismo , Neoplasias Colorretais/metabolismo , Modelos Animais de Doenças , Inflamação/metabolismo , Inflamação/prevenção & controle , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
11.
Cancer Invest ; 36(1): 10-18, 2018 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-29381400

RESUMO

CXCL12 is an extracellular chemokine binding to cell surface receptor CXCR4. We found that activation of CXCL12/CXCR4 axis stimulated angiogenesis in endothelial cells. Knockdown of CXCR4 in endothelial cells prevented the branch points of angiogenesis. Endothelial cells exposed to CXCL12 presented high level of epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), and matrix metalloproteinase MMP-2, but not in CXCR4 knockdown cells. Further studies revealed that activation of CXCL12/CXCR4 axis in vascular endothelial cells stimulates the angiogenesis through upregulation of the MAPK/ERK and PI3K/AKT and Wnt/ß-catenin pathways. Conclusion, downregulation of CXCR4 could inhibit angiogenesis in cancer tissues.


Assuntos
Quimiocina CXCL12/genética , Regulação para Baixo/genética , Regulação Neoplásica da Expressão Gênica/genética , Neovascularização Patológica/genética , Receptores CXCR4/genética , Transdução de Sinais/genética , Linhagem Celular , Células Endoteliais/metabolismo , Receptores ErbB/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Sistema de Sinalização das MAP Quinases/genética , Metaloproteinase 2 da Matriz/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Regulação para Cima/genética , Fator A de Crescimento do Endotélio Vascular/genética , Via de Sinalização Wnt/genética , beta Catenina/genética
12.
Anal Bioanal Chem ; 408(26): 7461-71, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27580608

RESUMO

A novel method of large volume of water samples directly introduced in dispersive liquid-liquid microextraction was developed, which is based on ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas (CO2) breaking down the emulsion for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry. This technique makes low-density extraction solvent toluene (180 µL) dissolve in 200 mL of samples containing 0.05 mol L(-1) of HCl and 5 % of NaCl (w/v) to form a well emulsion by synergy of ultrasound and manual shaking, and injects NaHCO3 solution (1.0 mol L(-1)) to generate CO2 achieving phase separation with the assistance of ultrasound. The entire process is accomplished within 8 min. The injection of NaHCO3 to generate CO2 achieves phase separation that breaks through the centrifugation limited large volume aqueous samples. In addition, the device could be easily cleaned, and this kind of vessel could be reconfigured for any volume of samples. Under optimal conditions, the low limits of detection ranging from 0.7 to 51.7 ng L(-1), wide linearity, and enrichment factors obtained were in the range 924-3669 for different triazole fungicides. Southern end of the Beijing-Hangzhou Grand Canal water (Hangzhou, China) was used to verify the applicability of the developed method. Graphical Abstract Flow chart of ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas breaking down the emulsion.

13.
J Sep Sci ; 39(23): 4603-4609, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27734583

RESUMO

A pretreatment method named tablet-effervescence-assisted dissolved carbon flotation was introduced for the determination of four triazole fungicides in environmental water. In this method, the use of effervescent tablet composed of nontoxic sodium carbonate and sodium dihydrogen phosphate could generate CO2 in situ to assist the dispersion of extraction solvent and to accelerate mass transfer of target analytes. In addition, the simple phase separation simply based on the rising of low-density organic solvent from the aqueous phase was applied rather than the application of apparatus, which demonstrated the potential for on-site extraction in the field. The experimental variables, including the composition of effervescent tablets, amount of effervescent tablets, types and volume of extraction solvent, were investigated. Under the optimized conditions, the method showed good linearity for myclobutanil, tebuconazole, epoxiconazole, and difenoconazole in the range of 1-100 µg/L. The limits of detection and the limits of quantification were within the range of 0.15-0.26 and 0.49-0.86 µg/L, respectively. The obtained correlation coefficients varied from 0.997 to 0.999, and suitable enrichment factors were 422-589. The recoveries were 82.5-112.9% with relative standard deviations of 4.7-13.5%.


Assuntos
Fungicidas Industriais/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Triazóis/isolamento & purificação , Carbono , Cromatografia Líquida de Alta Pressão , Comprimidos , Água
14.
J Sep Sci ; 39(6): 1173-81, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26833965

RESUMO

An ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction was first employed to determine the volatile components in tobacco samples. The method combined the advantages of ultrasound, microwave, and headspace solid-phase microextraction. The extraction, separation, and enrichment were performed in a single step, which could greatly simplify the operation and reduce the whole pretreatment time. In the developed method, several experimental parameters, such as fiber type, ultrasound power, and irradiation time, were optimized to improve sampling efficiency. Under the optimal conditions, there were 37, 36, 34, and 36 components identified in tobacco from Guizhou, Hunan, Yunnan, and Zimbabwe, respectively, including esters, heterocycles, alkanes, ketones, terpenoids, acids, phenols, and alcohols. The compound types were roughly the same while the contents were varied from different origins due to the disparity of their growing conditions, such as soil, water, and climate. In addition, the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method was compared with the microwave-assisted extraction coupled to headspace solid-phase microextraction and headspace solid-phase microextraction methods. More types of volatile components were obtained by using the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction method, moreover, the contents were high. The results indicated that the ultrasound-microwave synergistic extraction coupled to headspace solid-phase microextraction technique was a simple, time-saving and highly efficient approach, which was especially suitable for analysis of the volatile components in tobacco.

15.
Cell Physiol Biochem ; 35(1): 201-12, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25591763

RESUMO

BACKGROUND/AIMS: Des-gamma-carboxy prothrombin (DCP), an aberrant prothrombin produced by hepatocellular carcinoma (HCC) cells, is known as a marker for HCC. Recent studies indicated that high levels of DCP are associated with the malignant potential of HCC. In this study, we aimed to investigate the association of DCP with gefitinib treatment failure in HCC and whether DCP counteracts gefitinib-induced growth inhibition and apoptosis of HCC. METHODS: The experiments were performed in HCC cell lines HepG2 and PLC/PRF/5. The effects of gefitinib on HCC in the presence or absence of DCP were evaluated by the 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide (MTT) assay. Apoptotic cells were identified by Annexin V-FITC/PI staining. Western blotting was performed to analyze the expressions of molecules related to the apoptotic caspase-dependent pathway and epidermal growth factor receptor (EGFR) pathway. RESULTS: Gefitinib inhibited HCC cell proliferation and induced apoptosis in HCC cells. The effects of gefitinib on HCC cells were antagonized by DCP. In the presence of DCP, HCC cells were resistant to the gefitinib-induced inhibition of proliferation and stimulation of apoptosis. DCP prevented the activation of the apoptotic caspase-dependent pathway induced by gefitinib. These antagonistic effects of DCP also arose from its ability to up-regulate EGFR, c-Met and hepatocyte growth factor (HGF) in HCC cells. CONCLUSION: DCP antagonized gefitinib-induced HCC cell growth inhibition by counteracting apoptosis and up-regulating the EGFR pathway. High levels of DCP might thus lead to low response rates or possibly no response to gefitinib in patients with HCC.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Precursores de Proteínas/farmacologia , Protrombina/farmacologia , Quinazolinas/farmacologia , Biomarcadores , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Caspases/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Receptores ErbB/metabolismo , Gefitinibe , Células Hep G2 , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Proteínas Proto-Oncogênicas c-met/metabolismo , Regulação para Cima/efeitos dos fármacos
16.
Cell Physiol Biochem ; 34(3): 903-15, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25200250

RESUMO

Des-γ-carboxy prothrombin (DCP) is a prothrombin precursor produced in hepatocellular carcinoma (HCC). Because of deficiency of vitamin K or γ-glutamyl carboxylase in HCC cells, the 10 glutamic acid (Glu) residues in prothrombin precursor did not completely carboxylate to γ-carboxylated glutamic acid (Gla) residues, leaving some Glu residues remained in N-terminal domain. These prothrombin precursors with Glu residues are called DCPs. DCP displays insufficient coagulation activity. Since Liebman reported an elevated plasma DCP in patients with HCC, DCP has been used in the diagnosis of HCC. Recently, its biological malignant potential has been specified to describe DCP as an autologous growth factor to stimulate HCC growth and a paracrine factor to integrate HCC with vascular endothelial cells. DCP was found to stimulate HCC growth through activation of the DCP-Met-JAK1-STAT3 signaling pathway. DCP might increase HCC invasion and metastasis through activation of matrix metalloproteinase (MMPs) and the ERK1/2 MAPK signaling pathway. DCP has also been found to play a crucial role in the formation of angiogenesis. DCP could increase the angiogenic factors released from HCC and vascular endothelial cells. These effects of DCP in angiogenesis might be related to activation of the DCP-KDR-PLC-γ-MAPK signaling pathway. In this article, we summarized recent studies on DCP in biological roles related to cancer progression and angiogenesis in HCC.


Assuntos
Carcinoma Hepatocelular/fisiopatologia , Substâncias de Crescimento/fisiologia , Neoplasias Hepáticas/fisiopatologia , Precursores de Proteínas/fisiologia , Protrombina/fisiologia , Biomarcadores/química , Biomarcadores Tumorais , Carcinoma Hepatocelular/diagnóstico , Humanos , Neoplasias Hepáticas/diagnóstico , Estrutura Molecular , Precursores de Proteínas/química , Protrombina/química
17.
PLoS One ; 19(7): e0305572, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38954711

RESUMO

Green leafy vegetables are an essential component of Chinese leafy vegetables. Due to their crisp stems and tender leaves, orderly harvester generally causes significant mechanical clamping damage. The physical and mechanical properties of green leafy vegetables are one of the important basis to design the orderly harvester. At the same time, they provide important parameters for the simulation and optimization of harvester. So, this paper measured the physical characteristic parameters of roots and stems of green leafy vegetables. Then, based on the TMS-Pro texture analyzer, the elasticity modulus of the roots and stems of green leafy vegetables were measured. The static friction coefficient, dynamic friction coefficient, and restitution coefficient of green leafy vegetables root-root, stem-stem, root-steel, and stem-steel were measured separately using a combination method of inclined plane and high-speed photography. Uniaxial compression creep experiments were carried out on whole and single leaf of green leafy vegetables using the TA.XT plus C universal testing machine. The constitutive equation of the four-element Burgers model was used to fit the deformation curve of the sample with time during the constant-pressure loading stage. The fitting determination coefficients R2 were all higher than 0.996, which verified the reasonable validity of the selected model. The above experimental results provide a parameter basis and theoretical support for the design and discrete element simulation optimization of orderly harvester critical components of green leafy vegetables.


Assuntos
Folhas de Planta , Raízes de Plantas , Verduras , Viscosidade , Folhas de Planta/química , Elasticidade , Caules de Planta/fisiologia
18.
Cell Rep ; 43(8): 114571, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39093698

RESUMO

Rice stripe virus (RSV) establishes infection in the ovaries of its vector insect, Laodelphax striatellus. We demonstrate that RSV infection delays ovarian maturation by inhibiting membrane localization of the vitellogenin receptor (VgR), thereby reducing the vitellogenin (Vg) accumulation essential for egg development. We identify the host protein L. striatellus Rab1 protein (LsRab1), which directly interacts with RSV nucleocapsid protein (NP) within nurse cells. LsRab1 is required for VgR surface localization and ovarian Vg accumulation. RSV inhibits LsRab1 function through two mechanisms: NP binding LsRab1 prevents GTP binding, and NP binding LsRab1-GTP complexes stimulates GTP hydrolysis, forming an inactive LsRab1 form. Through this dual inhibition, RSV infection prevents LsRab1 from facilitating VgR trafficking to the cell membrane, leading to inefficient Vg uptake. The Vg-VgR pathway is present in most oviparous animals, and the mechanisms detailed here provide insights into the vertical transmission of other insect-transmitted viruses of medical and agricultural importance.


Assuntos
Receptores de Superfície Celular , Tenuivirus , Proteínas rab1 de Ligação ao GTP , Animais , Feminino , Proteínas rab1 de Ligação ao GTP/metabolismo , Tenuivirus/fisiologia , Tenuivirus/metabolismo , Receptores de Superfície Celular/metabolismo , Proteínas do Ovo/metabolismo , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Vitelogeninas/metabolismo , Proteínas do Nucleocapsídeo/metabolismo , Hemípteros/virologia , Hemípteros/metabolismo , Ovário/virologia , Ovário/metabolismo , Ligação Proteica , Transporte Proteico , Membrana Celular/metabolismo , Membrana Celular/virologia , Doenças das Plantas/virologia
19.
Future Med Chem ; 15(4): 333-344, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36946221

RESUMO

Aim: Because of the severe morbidity and mortality of gastric cancer, discovering new candidate drugs has been an urgent issue. The close association between histone deacetylase 6 (HDAC6) and gastric cancer makes the development of HDAC6-targeted anti-gastric cancer drugs a viable idea. Methods & results: Carbenoxolone disodium was identified as a novel HDAC6 inhibitor. Cellular thermal shift assay, surface plasmon resonance assay and molecular docking confirmed its binding ability to HDAC6. Cell viability, wound healing and transwell assays as well as animal studies have demonstrated that carbenoxolone disodium could block the proliferation and migration of gastric cancer cells MGC-803 in vitro and in vivo. Conclusion: This is the first report to indicate that carbenoxolone disodium could be an HDAC6 inhibitor with potential for treatment of gastric cancer.


Assuntos
Histona Desacetilases , Neoplasias , Animais , Desacetilase 6 de Histona , Histona Desacetilases/metabolismo , Carbenoxolona , Simulação de Acoplamento Molecular , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/química
20.
Sci Rep ; 13(1): 7798, 2023 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-37179376

RESUMO

Aiming at the problems of low fertilization efficiency, mainly the process operation and inconsistent fertilization depth of domestic tea garden fertilizer machines, a single-spiral fixed depth ditching and fertilizing machine is appropriately designed. This machine is capable of performing the integrated operation of ditching, fertilization, and covering soil at the same time through the operation mode of single-spiral ditching and fertilization. The theoretical analysis and design of the structure of the main components are properly carried out. The fertilization depth can be adjusted through the established depth control system. The performance test reveals that the single-spiral ditching and fertilizing machine exhibits a maximum stability coefficient of 96.17% and a minimum of 94.29% in terms of trenching depth and a maximum of 94.23% and a minimum of 93.58% in terms of fertilization uniformity, meeting the production requirements of tea plantations.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA