Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 113
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
BMC Med Imaging ; 24(1): 244, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39285364

RESUMO

PURPOSE: To investigate the application value of support vector machine (SVM) model based on diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) and amide proton transfer- weighted (APTW) imaging in predicting isocitrate dehydrogenase 1(IDH-1) mutation and Ki-67 expression in glioma. METHODS: The DWI, DCE and APTW images of 309 patients with glioma confirmed by pathology were retrospectively analyzed and divided into the IDH-1 group (IDH-1(+) group and IDH-1(-) group) and Ki-67 group (low expression group (Ki-67 ≤ 10%) and high expression group (Ki-67 > 10%)). All cases were divided into the training set, and validation set according to the ratio of 7:3. The training set was used to select features and establish machine learning models. The SVM model was established with the data after feature selection. Four single sequence models and one combined model were established in IDH-1 group and Ki-67 group. The receiver operator characteristic (ROC) curve was used to evaluate the diagnostic performance of the model. Validation set data was used for further validation. RESULTS: Both in the IDH-1 group and Ki-67 group, the combined model had better predictive efficiency than single sequence model, although the single sequence model had a better predictive efficiency. In the Ki-67 group, the combined model was built from six selected radiomics features, and the AUC were 0.965 and 0.931 in the training and validation sets, respectively. In the IDH-1 group, the combined model was built from four selected radiomics features, and the AUC were 0.997 and 0.967 in the training and validation sets, respectively. CONCLUSION: The radiomics model established by DWI, DCE and APTW images could be used to detect IDH-1 mutation and Ki-67 expression in glioma patients before surgery. The prediction performance of the radiomics model based on the combination sequence was better than that of the single sequence model.


Assuntos
Neoplasias Encefálicas , Glioma , Isocitrato Desidrogenase , Antígeno Ki-67 , Mutação , Máquina de Vetores de Suporte , Humanos , Isocitrato Desidrogenase/genética , Glioma/diagnóstico por imagem , Glioma/genética , Glioma/metabolismo , Antígeno Ki-67/metabolismo , Antígeno Ki-67/genética , Pessoa de Meia-Idade , Feminino , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Masculino , Estudos Retrospectivos , Adulto , Idoso , Imagem de Difusão por Ressonância Magnética/métodos , Imagem Multimodal , Adulto Jovem , Imageamento por Ressonância Magnética/métodos , Curva ROC , Meios de Contraste
2.
J Magn Reson Imaging ; 2023 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-37888871

RESUMO

BACKGROUND: The metastatic vascular patterns of hepatocellular carcinoma (HCC) are mainly microvascular invasion (MVI) and vessels encapsulating tumor clusters (VETC). However, most existing VETC-related radiological studies still focus on the prediction of VETC status. PURPOSE: This study aimed to build and compare VETC-MVI related models (clinical, radiomics, and deep learning) associated with recurrence-free survival of HCC patients. STUDY TYPE: Retrospective. POPULATION: 398 HCC patients (349 male, 49 female; median age 51.7 years, and age range: 22-80 years) who underwent resection from five hospitals in China. The patients were randomly divided into training cohort (n = 358) and test cohort (n = 40). FIELD STRENGTH/SEQUENCE: 3-T, pre-contrast T1-weighted imaging spoiled gradient recalled echo (T1WI SPGR), T2-weighted imaging fast spin echo (T2WI FSE), and contrast enhanced arterial phase (AP), delay phase (DP). ASSESSMENT: Two radiologists performed the segmentation of HCC on T1WI, T2WI, AP, and DP images, from which radiomic features were extracted. The RFS related clinical characteristics (VETC, MVI, Barcelona stage, tumor maximum diameter, and alpha fetoprotein) and radiomic features were used to build the clinical model, clinical-radiomic (CR) nomogram, deep learning model. The follow-up process was done 1 month after resection, and every 3 months subsequently. The RFS was defined as the date of resection to the date of recurrence confirmed by radiology or the last follow-up. Patients were followed up until December 31, 2022. STATISTICAL TESTS: Univariate COX regression, least absolute shrinkage and selection operator (LASSO), Kaplan-Meier curves, log-rank test, C-index, and area under the curve (AUC). P < 0.05 was considered statistically significant. RESULTS: The C-index of deep learning model achieved 0.830 in test cohort compared with CR nomogram (0.731), radiomic signature (0.707), and clinical model (0.702). The average RFS of the overall patients was 26.77 months (range 1-80 months). DATA CONCLUSION: MR deep learning model based on VETC and MVI provides a potential tool for survival assessment. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 3.

3.
Acta Pharmacol Sin ; 44(4): 877-887, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36207403

RESUMO

Neuroblastoma is the most common and deadliest tumor in infancy. WDR5 (WD Repeat Domain 5), a critical factor supporting an N-myc transcriptional complex via its WBM site and interacting with chromosome via its WIN site, promotes the progression of neuroblastoma, thus making it a potential anti-neuroblastoma drug target. So far, a few WIN site inhibitors have been reported, and the WBM site disruptors are rare to see. In this study we conducted virtual screening to identify candidate hit compounds targeting the WBM site of WDR5. As a result, 60 compounds were selected as candidate WBM site inhibitors. Cell proliferation assay demonstrated 6 structurally distinct WBM site inhibitors, numbering as compounds 4, 7, 11, 13, 19 and 22, which potently suppressed 3 neuroblastoma cell lines (MYCN-amplified IMR32 and LAN5 cell lines, and MYCN-unamplified SK-N-AS cell line). Among them, compound 19 suppressed the proliferation of IMR32 and LAN5 cells with EC50 values of 12.34 and 14.89 µM, respectively, and exerted a moderate inhibition on SK-N-AS cells, without affecting HEK293T cells at 20 µM. Analysis of high-resolution crystal complex structure of compound 19 against WDR5 revealed that it competitively occupied the hydrophobic pocket where V264 was located, which might disrupt the interaction of MYC with WDR5 and further MYC-medicated gene transcription. By performing RNA-seq analysis we demonstrated the differences in molecular action mechanisms of the compound 19 and a WIN site inhibitor OICR-9429. Most interestingly, we established the particularly high synergy rate by combining WBM site inhibitor 19 and the WIN site inhibitor OICR-9429, providing a novel therapeutic avenue for neuroblastoma.


Assuntos
Di-Hidropiridinas , Neuroblastoma , Humanos , Proteína Proto-Oncogênica N-Myc/genética , Células HEK293 , Compostos de Bifenilo , Neuroblastoma/tratamento farmacológico , Neuroblastoma/metabolismo , Linhagem Celular Tumoral , Peptídeos e Proteínas de Sinalização Intracelular
4.
Acta Pharmacol Sin ; 44(7): 1475-1486, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36725884

RESUMO

The KRASG12C mutant has emerged as an important therapeutic target in recent years. Covalent inhibitors have shown promising antitumor activity against KRASG12C-mutant cancers in the clinic. In this study, a structure-based and focused chemical library analysis was performed, which led to the identification of 143D as a novel, highly potent and selective KRASG12C inhibitor. The antitumor efficacy of 143D in vitro and in vivo was comparable with that of AMG510 and of MRTX849, two well-characterized KRASG12C inhibitors. At low nanomolar concentrations, 143D showed biochemical and cellular potency for inhibiting the effects of the KRASG12C mutation. 143D selectively inhibited cell proliferation and induced G1-phase cell cycle arrest and apoptosis by downregulating KRASG12C-dependent signal transduction. Compared with MRTX849, 143D exhibited a longer half-life and higher maximum concentration (Cmax) and area under the curve (AUC) values in mouse models, as determined by tissue distribution assays. Additionally, 143D crossed the blood‒brain barrier. Treatment with 143D led to the sustained inhibition of KRAS signaling and tumor regression in KRASG12C-mutant tumors. Moreover, 143D combined with EGFR/MEK/ERK signaling inhibitors showed enhanced antitumor activity both in vitro and in vivo. Taken together, our findings indicate that 143D may be a promising drug candidate with favorable pharmaceutical properties for the treatment of cancers harboring the KRASG12C mutation.


Assuntos
Proteínas Proto-Oncogênicas p21(ras) , Transdução de Sinais , Animais , Camundongos , Proteínas Proto-Oncogênicas p21(ras)/genética , Linhagem Celular Tumoral , Acetonitrilas/farmacologia , Mutação
5.
Mikrochim Acta ; 190(2): 66, 2023 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-36692590

RESUMO

Blue fluorescent carbon dots (PCDs) were prepared by hydrothermal method with Partridge tea. The ethanol extract of Partridge tea (PEE) was found to emit red fluorescence. Thus, a novel ratiometric sensor was constructed by simply mixing the two fluorophores derived from Partridge tea. The presence of tetracycline (TET) at lower concentrations enhanced the emission peak at 508 nm of PCDs and had a negligible effect on the emission peak at 680 nm of PEE. TET at higher concentrations led to  quenching  both the fluorescence of PCDs and PEE via inner filter effect and fluorescence resonance energy transfer, separately. Good linearities for the detection of TET were obtained in the ranges 0.67 to 15.00 µM and 33.33 to 266.67 µM, with limit of detection of 0.095 µM. The sensor was successfully applied to detect TET in lake water and milk samples with good recoveries ranging from 93.27 ± 4.04% to 107.30 ± 6.16%. This study provided a simple, selective, sensitive, rapid, and environmentally friendly method of monitoring TET residues in the environment and food.


Assuntos
Pontos Quânticos , Pontos Quânticos/química , Limite de Detecção , Tetraciclina/análise , Antibacterianos/análise , Chá
6.
Anal Chem ; 94(22): 8058-8065, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35611971

RESUMO

The detection and therapy of cancers in the early stage significantly alleviate the associated dangers. Optical devices offer new opportunities for these early measures. However, the clinical translation of the existing methods is severely hindered by their relatively low sensitivity or unclear physiological metabolism. Here, an optical microfiber sensor with a drug loading gold nanorod-black phosphorous nanointerface, as an ultrasensitive biosensor and nanotherapy platform, is developed to meet the early-stage requirement. With interface sensitization and functionalization of the hybrid nanointerface, the microfiber sensor presents an ultrahigh sensing performance, achieving the selective detection of the HER2 biomarker with limits of detection of 0.66 aM in buffer solution and 0.77 aM in 10% serum. It can also distinguish breast cancer cells from other cells in the early stage. Additionally, enabled by the interface, the optical microfiber is able to realize cellular nanotherapy, including photothermal/chemotherapy with pump laser coupling after diagnosis, and evaluate therapy results in real time. The immobilization of the interface on the optical microfiber surface prevents the damage to normal cells induced by nanomaterial enrichment, making the device more efficient and intelligent. This study opens up a new avenue for the development of smart optical platforms for sensitive biosensing and precision therapy.


Assuntos
Técnicas Biossensoriais , Nanotubos , Dispositivos Ópticos , Ouro , Fósforo
7.
Langmuir ; 38(37): 11440-11450, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36075054

RESUMO

Oil-impregnated porous polyimide (PI) materials can provide continuous lubricant supply, which is widely used to manufacture space rolling bearing retainers. The lubrication performance of porous polyimide materials mainly depends on their ability to release and recycle lubricants, which is closely related to pore size. In this paper, to investigate the effect of pore size, porous polyimide materials with different pore sizes were prepared by preheating the retainer tube billet during the limit pressing process. The lubricant content rates at each stage were measured by the lubricant immersion and centrifugal release experiment to show the variation of the lubricant content rate in the porous PI sample during a working cycle. At first, the lubricant can be absorbed into the pore. It is found that the absorption rate is faster for lubricants with a smaller viscosity. Moreover, lubricant thinning caused by temperature rise also improves the absorption rate. After lubricant absorption to saturation, the lubricant is released under the centrifugal effect to provide the lubricant. Increasing pore size and using low-viscosity lubricants are the main ways to improve lubrication. Finally, the lubricant on the surface can be recycled into the pore by capillary effect. The smaller the pore size, the faster the lubricant recycles to saturation. These insights gained in this study can provide guidance for the choice of an oil-impregnated porous retainer in different working conditions.

8.
Cell Mol Biol (Noisy-le-grand) ; 68(2): 26-30, 2022 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-35869730

RESUMO

This study aimed to investigate the inhibitory effect and mechanism of neurotropin on inflammation in rats with lumbar disc herniation. For this purpose, forty-eight rats were randomly divided into sham group, autologous nucleus pulposus transplantation model group (NP group), neurotropin treatment group (NP+NT group), and solvent [normal saline (NS)] control group (NP+NS group). After 7 days of intervention, the mechanical paw withdrawal threshold (PWT) and thermal paw withdrawal latency (PWL) of the rats were measured, and the expression levels of Iba-1, c-JNK and CXCL1 in spinal cord tissues were measured by Western blot. The levels of tissue-associated inflammatory and anti-inflammatory factors in the spinal cord were detected by ELISA. Results showed that Neurotropin significantly alleviated mechanical and thermal hyperalgesia induced by NP transplantation and reduced levels of Iba-1, c-JNK, and CXCL1 proteins in the spinal cord tissue. In addition, neurotoxins also lowered concentrations of the inflammatory factors IL-1ß, IL-6 and TNF-α. It was concluded that Neurotropin has an inhibitory effect on lumbar disc herniation-induced spinal cord inflammation through inhibition of the c-JNK/CXCL signaling pathway.


Assuntos
Deslocamento do Disco Intervertebral , Animais , Quimiocina CXCL1/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Deslocamento do Disco Intervertebral/tratamento farmacológico , Deslocamento do Disco Intervertebral/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Polissacarídeos/metabolismo , Ratos , Medula Espinal/metabolismo
9.
Cell Mol Biol (Noisy-le-grand) ; 67(5): 293-301, 2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35818240

RESUMO

This study aimed to investigate the expression of miR-221 and miR-145 in papillary thyroid carcinoma, and the effect of miR-221 and miR-145 on the invasion ability of thyroid cancer cells and its mechanism. For this purpose, 120 patients with thyroid nodules were divided into the observation group (PTC) of 43 cases and the control group (benign nodules) of 42 cases according to postoperative pathological diagnosis. Total RNA was extracted from serum samples of all patients, and the expression levels of miRNA-145 and miR-221 were detected by fluorescence quantitative PCR. The expression of two kinds of miRNAs in the groups was compared, and their correlation was analyzed. The results showed that the expression of miRNA-145 in thyroid cancer tissues was lower than that in paired adjacent normal tissues (P < 0.001). The expression of miRNA-221 in thyroid cancer tissues was higher than that in paired adjacent normal tissues (P < 0.001). The proliferation and migration ability of miRNA-145 cells were significantly decreased (P < 0.01). The expression of miRNA-221 was up-regulated, and the proliferation and migration ability of cells was significantly enhanced (P < 0.05). High expression of miRNA-145 can inhibit cell proliferation and migration and promote apoptosis, while high expression of miRNA-221 will promote cell proliferation and migration and enhance the invasion ability of cancer cells. In general, the expression of miRNA-22l in serum of PTC patients is significantly up-regulated, while the expression level of miR-145 is down-regulated, which can be used as effective indicators to judge the biological activity of the tumor, and the combined detection of the two can significantly enhance the diagnostic value of PTC. Upregulation of miR-145 inhibits PTC cell proliferation; arrests cell cycle and promotes apoptosis miR-145 may play an important role as a tumor suppressor gene.


Assuntos
Carcinoma Papilar , MicroRNAs , Neoplasias da Glândula Tireoide , Carcinoma Papilar/diagnóstico , Carcinoma Papilar/genética , Carcinoma Papilar/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/sangue , Câncer Papilífero da Tireoide/genética , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia
10.
Int J Clin Oncol ; 27(9): 1379-1385, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35790652

RESUMO

To evaluate the oncological safety of autologous fat grafting and its effect on disease-free survival and local recurrence in breast cancer patients with autologous fat grafting (AFG) reconstruction. A literature search was performed using the Pubmed, Medline, Web of Science, and Cochrane libraries from January 2011 to March 2020, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to identify all relevant studies involving the application of autologous fat grafting in breast cancer reconstruction procedures. The primary outcome of the meta-analysis was a difference in incidence rates of locoregional recurrence and disease-free survival (DFS) between patients who had autologous fat grafting and controls. A total of 11 studies were included. Eight studies reported local-regional recurrences (LRR) and five studies reported disease-free survival (DFS) in 5,886 patients. Our meta-analysis of all included studies about survival outcomes showed AFG was not associated with increased LRR and DFS. Pooled hazard ratios (HRs) (95% CIs) for LRR and DFS were 1.26 (0.90-1.76) and 1.27 (0.96-1.69), respectively. According to the published literature, autologous fat grafting did not result in an increased rate of LRR and DFS in patients with breast cancer. Autologous fat grafting can, therefore, be performed safely in breast reconstruction after breast cancer.


Assuntos
Neoplasias da Mama , Mamoplastia , Tecido Adiposo/transplante , Neoplasias da Mama/cirurgia , Feminino , Humanos , Mamoplastia/efeitos adversos , Mamoplastia/métodos , Recidiva Local de Neoplasia/cirurgia , Transplante Autólogo/efeitos adversos
11.
Nucleic Acids Res ; 48(5): 2733-2748, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32009146

RESUMO

Family with sequence similarity (FAM46) proteins are newly identified metazoan-specific poly(A) polymerases (PAPs). Although predicted as Gld-2-like eukaryotic non-canonical PAPs, the detailed architecture of FAM46 proteins is still unclear. Exact biological functions for most of FAM46 proteins also remain largely unknown. Here, we report the first crystal structure of a FAM46 protein, FAM46B. FAM46B is composed of a prominently larger N-terminal catalytic domain as compared to known eukaryotic PAPs, and a C-terminal helical domain. FAM46B resembles prokaryotic PAP/CCA-adding enzymes in overall folding as well as certain inter-domain connections, which distinguishes FAM46B from other eukaryotic non-canonical PAPs. Biochemical analysis reveals that FAM46B is an active PAP, and prefers adenosine-rich substrate RNAs. FAM46B is uniquely and highly expressed in human pre-implantation embryos and pluripotent stem cells, but sharply down-regulated following differentiation. FAM46B is localized to both cell nucleus and cytosol, and is indispensable for the viability of human embryonic stem cells. Knock-out of FAM46B is lethal. Knock-down of FAM46B induces apoptosis and restricts protein synthesis. The identification of the bacterial-like FAM46B, as a pluripotent stem cell-specific PAP involved in the maintenance of translational efficiency, provides important clues for further functional studies of this PAP in the early embryonic development of high eukaryotes.


Assuntos
Células-Tronco Embrionárias Humanas/metabolismo , Nucleotidiltransferases/metabolismo , Polinucleotídeo Adenililtransferase/metabolismo , Células Procarióticas/metabolismo , Animais , Biocatálise , Linhagem Celular , Sobrevivência Celular , Desenvolvimento Embrionário , Humanos , Modelos Moleculares , Nucleotidiltransferases/química , Nucleotidiltransferases/genética , Polinucleotídeo Adenililtransferase/química , Ligação Proteica , Domínios Proteicos , RNA/metabolismo , Especificidade por Substrato , Xenopus
12.
BMC Plant Biol ; 21(1): 600, 2021 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-34922452

RESUMO

BACKGROUND: Overuse of chemical fertilizer highly influences grain filling rate and quality of rice grain. Biochar is well known for improving plant growth and grain yield under lower chemical fertilization. Therefore field trials were conducted in the early and late seasons of 2019 at Guangxi University, China to investigate the effects of combined biochar (B) and nitrogen (N) application on rice yield and yield components. There were a total of eight treatments: N1B0, 135 kg N ha- 1+ 0 t B ha- 1; N2B0,180 kg N ha- 1+ 0 t B ha- 1; N1B1,135 kg N ha- 1+ 10 t B ha- 1; N1B2,135kg N ha- 1+ 20 t B ha- 1; N1B3,135 kg N ha- 1+ 30 t B ha- 1; N2B1,180 kg N ha- 1+ 10 t B ha- 1; N2B2,180 kg N ha- 1+ 20 t B ha- 1; and N2B3,180 kg N ha- 1+ 30 t B ha- 1. RESULTS: Biochar application at 30 t ha- 1combined with low N application (135 kg ha- 1) increased the activity of starch-metabolizing enzymes (SMEs) during the early and late seasons compared with treatments without biochar. The grain yield, amylose concentration, and starch content of rice were increased in plots treated with 30 t B ha-1and low N. RT-qPCR analysis showed that biochar addition combined with N fertilizer application increased the expression of AGPS2b, SSS1, GBSS1, and GBSE11b, which increased the activity of SMEs during the grain-filling period. CONCLUSION: Our results suggest that the use of 20 to 30 t B ha- 1coupled with 135 kg N ha- 1 is optimal for improving the grain yield and quality of rice.


Assuntos
Carvão Vegetal/farmacologia , Fertilizantes , Nitrogênio/farmacologia , Oryza/efeitos dos fármacos , Enzima Ramificadora de 1,4-alfa-Glucana/genética , Enzima Ramificadora de 1,4-alfa-Glucana/metabolismo , Agricultura , Amilose/metabolismo , China , Ativação Enzimática , Enzimas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Oryza/enzimologia , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Amido/metabolismo
13.
Langmuir ; 37(30): 9162-9169, 2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34297577

RESUMO

The retainer of a space rolling bearing widely made of porous polyimide (PI) materials is oil-impregnated and can continuously release lubricants for lubrication. Understanding the lubricant supply mechanism in porous polyimide retainers is important to improve the lubrication performance of space bearings and therefore extends the bearing life. In this work, molecular dynamics simulations are adopted to model the lubricant outflow process from the pore of the PI material. Coarse-grained models are constructed to investigate the lubricant migration behaviors with different pore sizes and radii of rotation. At rest, a lubricant within the pore fails to outflow due to the capillary effect, which decreases with the increase of the pore size. However, for the rotating pores, if the inertial forces generated by the rotational motion exceed the capillary forces, the lubricants will begin to accumulate and some of the lubricants will flow out. Furthermore, the lubricant in the larger pore is easier to outflow due to the smaller capillary forces. This study quantifies the inertial effect and reveals that the centrifugal force is the main mechanism of lubricant outflow from the pores.

14.
Langmuir ; 37(7): 2426-2435, 2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33560132

RESUMO

Porous polyimide (PI) materials are one of important bearing retainer materials in space applications due to the storage and continuous supply of a lubricant through the porous structure. Understanding the lubricant recycling process in porous polyimide retainers is of vital importance to improve lubricant supply performance of bearing. In this work, through molecular dynamic simulations, coarse-grained models are built to study lubricant recycling processes on porous and solid surfaces. A spontaneous imbibition behavior is observed when the lubricant is present on the porous surface. The dynamic change in the contact angle in this process and the deviation of the effective radius from the volumetric radius because of the molecular structure of polyimide causes the classical Lucas-Washburn (L-W) equation fail to describe the process. By fitting dynamic contact angle and effective radius, a modified L-W equation is developed, which well predicts the process of imbibition. Furthermore, it is found that the lubricants between the porous polyimide surface and the solid surface are recycled by extrusion, and spontaneous imbibition does not occur. In this case, the accumulation of lubricant pressure and weak interfacial interaction between the lubricant and the solid surface are also the main factors that promote lubricant recycling.

15.
Liver Int ; 41(2): 378-387, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32562336

RESUMO

BACKGROUND & AIMS: The lymphocyte-C-reactive protein ratio (LCR) is a novel inflammatory-based score, based solely on the lymphocyte and C-reactive protein. We aimed to clarify the prognostic value of the LCR score in intrahepatic cholangiocarcinoma (ICC) patients after resection. METHODS: We compared the prognostic accuracy of the LCR score with other inflammatory-based scores in this large, multicentre cohort study. The independent variables associated with overall survival (OS) were explored in both the primary (n = 228) and validation cohorts (n = 135). Harrell's concordance index (C-index) was used to compare the predictive ability of all the assessed inflammatory-based scores. RESULTS: The LCR score was differentiated two groups of ICC patients with distinct prognoses (1-, 3-, and 5-year OS rates: 94.4%, 66.3%, and 59.3%; and 66.6%, 45.6%, and 32.7%, respectively) (P < .001). Multivariate analysis showed that the LCR score, as well as the TNM stage and preoperative CA19-9 level, were independently associated with OS. The predictive accuracy of the LCR score (c score: 0.634) was superior to that of the other inflammatory-based scores (c scores: 0.508-0.615). These findings were supported by the external validation cohort. CONCLUSION: The LCR score is stable and consistently the best prognostic score and may offer as a simple, objective and discriminatory method in facilitating the risk stratification of ICC patients.


Assuntos
Neoplasias dos Ductos Biliares , Colangiocarcinoma , Neoplasias dos Ductos Biliares/cirurgia , Proteína C-Reativa , Colangiocarcinoma/cirurgia , Estudos de Coortes , Hepatectomia , Humanos , Linfócitos , Prognóstico
16.
Chem Eng J ; 407: 127143, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33013189

RESUMO

Portable devices, which can detect and characterize the individual nanoparticles in real time, are of insignificant interest for early diagnosis, homeland security, semiconductor manufacturing and environmental monitoring. Optical microfibers present a good potential in this field, however, are restricted by the sensitivity limit. This study reports the development of a 3D plasmonic nanointerface, which is made of a Cu-BTC framework supporting Cu3-xP nanocrystals, enhancing the optical microfiber for real-time detection and sizing of single nanoparticles. The Cu3-xP nanocrystals are successfully embedded in the 3D Cu-BTC framework. The localized-surface plasmon resonance is tuned to coincide with the evanescent field of the optical microfiber. The 3D Cu-BTC framework, as the scaffold of nanocrystals, confines the local resonance field on the microfiber with three dimensions, at which the binding of target nanoparticles occurs. Based on the evanescent field confinement and surface enhancement by the nanointerface, the optical microfiber sensor overcomes its sensitivity limit, and enables the detection and sizing of the individual nanoparticles. The compact size and low optical power supply of the sensor confirm its suitability as a portable device for the real-time single-nanoparticle characterization, especially for the convenient evaluation of the ultrafine particles in the environment. This work opens up an approach to overcome the sensitivity limit of the optical microfibers, as long with stimulating the portable real-time single-nanoparticle detection and sizing.

17.
Stem Cells ; 37(11): 1401-1415, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31348575

RESUMO

Histone methyltransferases play a critical role in early human development, whereas their roles and precise mechanisms are less understood. SET and MYND domain-containing protein 2 (SMYD2) is a histone lysine methyltransferase induced during early differentiation of human embryonic stem cells (hESCs), but little is known about its function in undifferentiated hESCs and in their early lineage fate decision as well as underlying mechanisms. Here, we explored the role of SMYD2 in the self-renewal and mesendodermal lineage commitment of hESCs. We demonstrated that the expression of SMYD2 was significantly enhanced during mesendodermal but not neuroectodermal differentiation of hESCs. SMYD2 knockout (SMYD2-/- ) did not affect self-renewal and early neuroectodermal differentiation of hESCs, whereas it blocked the mesendodermal lineage commitment. This phenotype was rescued by reintroduction of SMYD2 into the SMYD2-/- hESCs. Mechanistically, the bindings of SMYD2 at the promoter regions of critical mesendodermal transcription factor genes, namely, brachyury (T), eomesodermin (EOMES), mix paired-like homeobox (MIXL1), and goosecoid homeobox (GSC) were significantly enhanced during mesendodermal differentiation of SMYD2+/+ hESCs but totally suppressed in SMYD2-/- ones. Concomitantly, such a suppression was associated with the remarkable reduction of methylation at histone 3 lysine 4 and lysine 36 but not at histone 4 lysine 20 globally and specifically on the promoter regions of mesendodermal genes, namely, T, EOMES, MIXL1, and GSC. These results reveal that the histone methyltransferase SMYD2 is dispensable in the undifferentiated hESCs and the early neuroectodermal differentiation, but it promotes the mesendodermal differentiation of hESCs through the epigenetic control of critical genes to mesendodermal lineage commitment. Stem Cells 2019;37:1401-1415.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Células-Tronco Embrionárias Humanas/citologia , Células-Tronco Embrionárias Humanas/metabolismo , Sequência de Bases , Ciclo Celular/genética , Ciclo Celular/fisiologia , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem Celular , Proteínas Fetais/genética , Proteínas Fetais/metabolismo , Citometria de Fluxo , Proteína Goosecoid/genética , Proteína Goosecoid/metabolismo , Histona-Lisina N-Metiltransferase/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Imuno-Histoquímica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Ativação Transcricional/genética , Ativação Transcricional/fisiologia
18.
BMC Cancer ; 20(1): 607, 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32600297

RESUMO

BACKGROUND: Small hepatocellular carcinoma (sHCC) is a special subtype of HCC with the maximum tumor diameter ≤ 3 cm and excellent long-term outcomes. Surgical resection or radiofrequency ablation provides the greatest chance for cure; however, many patients still undergo tumor recurrence after primary treatment. To date, there is no clinical applicable method to assess biological aggressiveness in solitary sHCC. METHODS: In the current study, we retrospectively evaluated tumor necrosis of 335 patients with solitary sHCC treated with hepatectomy between December 1998 and 2010 from Sun Yat-sen University Cancer Center. RESULTS: The presence of tumor necrosis was observed in 157 of 335 (46.9%) sHCC patients. Further correlation analysis showed that tumor necrosis was significantly correlated with tumor size and vascular invasion (P = 0.026, 0.003, respectively). The presence of tumor necrosis was associated closely with poorer cancer-specific overall survival (OS) and recurrence-free survival (RFS) as evidenced by univariate (P <  0.001; hazard ratio, 2.821; 95% CI, 1.643-4.842) and multivariate analysis (P = 0.005; hazard ratio, 2.208; 95% CI, 1.272-3.833). Notably, the combined model by tumor necrosis, vascular invasion and tumor size can significantly stratify the risk for RFS and OS and improve the ability to discriminate sHCC patients' outcomes (P <  0.0001 for both). CONCLUSIONS: Our results provide evidence that tumor necrosis has the potential to be a parameter for cancer aggressiveness in solitary sHCC. The combined prognostic model may be a useful tool to identify solitary sHCC patients with worse outcomes.


Assuntos
Carcinoma Hepatocelular/cirurgia , Hepatectomia , Neoplasias Hepáticas/cirurgia , Fígado/patologia , Recidiva Local de Neoplasia/epidemiologia , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Intervalo Livre de Doença , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Fígado/cirurgia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Necrose/epidemiologia , Necrose/patologia , Invasividade Neoplásica/patologia , Prognóstico , Estudos Retrospectivos , Medição de Risco/métodos , Fatores de Risco , Carga Tumoral
19.
Circ Res ; 122(7): 958-969, 2018 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-29343525

RESUMO

RATIONALE: Human pluripotent stem cell-derived cardiovascular progenitor cells (hPSC-CVPCs) should be thoroughly investigated in large animal studies before testing in clinical trials. OBJECTIVE: The main of this study is to clarify whether hPSC-CVPCs can engraft for long time in the heart of primates after myocardial infarction (MI) and compare the effectiveness and safety of immunosuppression with cyclosporine alone or multiple-drug regimen (MDR) containing cyclosporine, methylprednisolone, and basiliximab in cynomolgus monkeys that had received intramyocardial injections of 1×107 EGFP (enhanced green fluorescent protein)-expressing hPSC-CVPCs after MI. A third group of animals received the immunosuppression MDR but without cell therapy after MI (MI+MDR group). METHODS AND RESULTS: Measurements of EGFP gene levels and EGFP immunofluorescence staining indicated that the hPSC-CVPC engraftment rate was greater in the MI+MDR+CVPC group than that in the MI+cyclosporine+CVPC group. However, even in the MI+MDR+CVPC group, no transplanted cells could be detected at 140 days after transplantation. Concomitantly, immunofluorescent analysis of CD3, CD4, and CD8 expression indicated that T-lymphocyte infiltration in the CVPC-transplanted hearts was less in the MDR-treated animals than in the cyclosporine-alone-treated animals. The recovery of left ventricular function on day 28 post-MI in the MI+MDR+CVPC group was better than that in the MI+MDR group. Apoptotic cardiac cells were also less common in the MI+MDR+CVPC group than in the MI+MDR group, although both immunosuppression regimens were associated with transient hepatic dysfunction. CONCLUSIONS: This is the largest study of hPSCs in nonhuman primates in cardiovascular field to date (n=32). Compared with cyclosporine alone, MDR attenuates immune rejection and improves survival of hPSC-CVPCs in primates; this is associated with less apoptosis of native cardiac cells and better recovery of left ventricular function at 28 days. However, even with MDR, transplanted hPSC-CVPCs do not engraft and do not survive at 140 days after transplantation, thereby excluding remuscularization as a mechanism for the functional effect.


Assuntos
Células-Tronco Embrionárias Humanas/citologia , Desenvolvimento Muscular , Mioblastos Cardíacos/transplante , Infarto do Miocárdio/terapia , Transplante de Células-Tronco/métodos , Animais , Linhagem Celular , Ciclosporina/administração & dosagem , Ciclosporina/efeitos adversos , Humanos , Terapia de Imunossupressão/efeitos adversos , Terapia de Imunossupressão/métodos , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Macaca fascicularis , Masculino , Mioblastos Cardíacos/citologia , Transplante de Células-Tronco/efeitos adversos
20.
Acta Pharmacol Sin ; 41(12): 1576-1586, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33037404

RESUMO

Type 2 inositol 1,4,5-trisphosphate receptor (IP3R2) regulates the intracellular Ca2+ release from endoplasmic reticulum in human embryonic stem cells (hESCs), cardiovascular progenitor cells (CVPCs), and mammalian cardiomyocytes. However, the role of IP3R2 in human cardiac development is unknown and its function in mammalian cardiomyocytes is controversial. hESC-derived cardiomyocytes have unique merits in disease modeling, cell therapy, and drug screening. Therefore, understanding the role of IP3R2 in the generation and function of human cardiomyocytes would be valuable for the application of hESC-derived cardiomyocytes. In the current study, we investigated the role of IP3R2 in the differentiation of hESCs to cardiomyocytes and in the hESC-derived cardiomyocytes. By using IP3R2 knockout (IP3R2KO) hESCs, we showed that IP3R2KO did not affect the self-renewal of hESCs as well as the differentiation ability of hESCs into CVPCs and cardiomyocytes. Furthermore, we demonstrated the ventricular-like myocyte characteristics of hESC-derived cardiomyocytes. Under the α1-adrenergic stimulation by phenylephrine (10 µmol/L), the amplitude and maximum rate of depolarization of action potential (AP) were slightly affected in the IP3R2KO hESC-derived cardiomyocytes at differentiation day 90, whereas the other parameters of APs and the Ca2+ transients did not show significant changes compared with these in the wide-type ones. These results demonstrate that IP3R2 has minimal contribution to the differentiation and function of human cardiomyocytes derived from hESCs, thus provide the new knowledge to the function of IP3R2 in the generation of human cardiac lineage cells and in the early cardiomyocytes.


Assuntos
Diferenciação Celular/fisiologia , Células-Tronco Embrionárias Humanas/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Miócitos Cardíacos/metabolismo , Regulação para Baixo , Humanos , Receptores Adrenérgicos alfa 1/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA