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1.
J Magn Reson Imaging ; 59(1): 7-31, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37154415

RESUMO

Recent studies have shown that MRI demonstrates promising results for evaluating the chemotherapy efficacy in bone sarcomas. This article reviews current methods for evaluating the efficacy of malignant bone tumors and the application of MRI in this area, and emphasizes the advantages and limitations of each modality. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Sarcoma de Ewing , Humanos , Sarcoma de Ewing/tratamento farmacológico , Sarcoma de Ewing/patologia , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Osteossarcoma/diagnóstico por imagem , Osteossarcoma/tratamento farmacológico , Imageamento por Ressonância Magnética
2.
J Magn Reson Imaging ; 57(3): 670-689, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36200754

RESUMO

Magnetic resonance diffusion kurtosis imaging (DKI) is an emerging magnetic resonance imaging (MRI) technique that can reflect microstructural changes in tissue through non-Gaussian diffusion of water molecules. Compared to traditional diffusion weighted imaging (DWI), the DKI model has shown greater sensitivity for diagnosis of musculoskeletal diseases and can help formulate more reasonable treatment plans. Moreover, DKI is an important auxiliary examination for evaluation of the motor function of the musculoskeletal system. This article briefly introduces the basic principles of DKI and reviews the application and research of DKI in the evaluation of disorders of the musculoskeletal system (including bone tumors, soft tissue tumors, spinal lesions, chronic musculoskeletal diseases, musculoskeletal trauma, and developmental disorders) as well as the normal musculoskeletal tissues. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: 1.


Assuntos
Imagem de Tensor de Difusão , Doenças Musculoesqueléticas , Humanos , Imagem de Tensor de Difusão/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Coluna Vertebral , Doenças Musculoesqueléticas/diagnóstico por imagem , Espectroscopia de Ressonância Magnética , Imageamento por Ressonância Magnética
3.
J Magn Reson Imaging ; 58(2): 630-639, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36444747

RESUMO

BACKGROUND: Reactive stroma is recognized as one of the independent prognostic factors in prostate cancer (PCa). Intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) may be useful for assessing the reactive stromal grade (RSG). PURPOSE: To investigate whether IVIM and DKI models can evaluate RSG in PCa patients. STUDY TYPE: Retrospective. SUBJECTS: A total of 56 PCa patients aged 73 years on average confirmed by MRI and transrectal ultrasound (MRI/TRUS) fusion biopsy divided into two subgroups (18 high RSG and 38 low RSG). FIELD STRENGTH/SEQUENCE: A 3 T/T1 WI-fs, T1 WI, T2 WI-fs, T2 WI, DWI, IVIM, and DKI. ASSESSMENT: Apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), mean diffusion (MD), mean kurtosis (MK) were obtained. Patients were divided into high RSG PCa (>50% reactive stroma) and low RSG PCa (≤50% reactive stroma) groups on hematoxylin and eosin (H&E) stained sections. STATISTICAL TESTS: Spearman correlation and independent sample t-test or Wilcoxon's rank sum test was used to investigate the relationship between each imaging parameter and RSG. The combined parameters were calculated using a binary logistic regression model. Receiver operating characteristic (ROC) analysis was used to explore the value of individual and combined parameters to differentiate between high and low RSG group. Area under the ROC curves (AUC) > 0.7 were used as reference standards. RESULTS: ADC, D, f, and MD values showed positive correlation with RSG (r = 0.489, 0.619, 0.318, and 0.544, respectively); MK showed negative correlation with RSG (r = -0.444). ADC, D, f, and MD values were significantly lower in the low RSG group than in the high RSG group. The combined model showed the best diagnostic ability to differentiate low and high RSG groups (AUC = 0.887). DATA CONCLUSION: Parameters of IVIM and DKI may be promising methods for assessment of RSG in PCa patients. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 3.


Assuntos
Imagem de Tensor de Difusão , Neoplasias da Próstata , Masculino , Humanos , Estudos Retrospectivos , Imagem de Tensor de Difusão/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Curva ROC , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Movimento (Física)
4.
J Magn Reson Imaging ; 57(5): 1406-1413, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35864603

RESUMO

BACKGROUND: Diffusion-weighted imaging (DWI) has demonstrated great potential in predicting the expression of tumor cell proliferation and apoptosis indexes. PURPOSE: To evaluate the impact of four region of interest (ROI) methods on interobserver variability and apparent diffusion coefficient (ADC) values and to examine the correlation of ADC values with Ki-67, Bcl-2, and P53 labeling indexes (LIs) in a murine model of fibrosarcoma. STUDY TYPE: Prospective, animal model. ANIMAL MODEL: A total of 22 female BALB/c mice bearing intramuscular fibrosarcoma xenografts. FIELD STRENGTH/SEQUENCE: A 3.0 T/T1-weighted fast spin-echo (FSE), T2-weighted fast relaxation fast spin-echo, and DWI PROPELLER FSE sequences. ASSESSMENT: Four radiologists measured ADC values using four ROI methods (oval, freehand, small-sample, and whole-volume). Immunohistochemical assessment of Ki-67, Bcl-2, and P53 LIs was performed. STATISTICAL TESTS: Interclass correlation coefficient (ICC), one-way analysis of variance followed by LSD-t post hoc analysis, and Pearson correlation test were performed. The statistical threshold was defined as a P-value of <0.05. RESULTS: All ROI methods for ADC measurements showed excellent interobserver agreement (ICC range, 0.832-0.986). The ADC values demonstrated significant differences among the four ROI methods. The ADC values for oval, freehand, small-sample, and whole-volume ROI methods showed a moderately negative correlation with Ki-67 (r = -0.623; r = -0.629; r = -0.642, and r = -0.431) and Bcl-2 (r = -0.590; r = -0.597; r = -0.659, and r = -0.425) LIs, but no correlation with P53 LI (r = 0.364, P = 0.104; r = 0.350, P = 0.120; r = 0.379, P = 0.091; r = 0.390, P = 0.080). DATA CONCLUSION: The ADC value can be used to evaluate cell proliferation and apoptosis indexes in a murine model of fibrosarcoma, employing the small-sample ROI as a reliable method. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 3.


Assuntos
Fibrossarcoma , Proteína Supressora de Tumor p53 , Humanos , Feminino , Animais , Camundongos , Antígeno Ki-67 , Estudos Prospectivos , Modelos Animais de Doenças , Reprodutibilidade dos Testes , Imageamento por Ressonância Magnética/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Proliferação de Células
5.
Anal Biochem ; 645: 114605, 2022 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-35181297

RESUMO

Kynurenine (Kyn) is involved in a variety of physiological/pathological reactions via activating aryl hydrocarbon receptor (Ahr). However, how to activate Ahr by Kyn under physiological/pathological conditions is still unclear. Here, we presented that Kyn (8 µM, a concentration less than the dose of Kyn-induced Ahr activation) significantly induced the nuclear transfer of Ahr and the expression of cytochrome P450 1A1 (CYP1A1, a classic biomarker for Ahr activation) when co-administered with ultraviolet (UV) irradiation in 95D cells, which were transfected transiently with siRNA against indoleamine 2,3-dioxygenase 1 (IDO 1) and cultured in cell medium supplemented with bovine serum containing bovine serum albumin (BSA), in vitro. Additionally, we found that the fluorescence intensity of BSA was attenuated by Kyn (2, 4, 6, 8, 10, 12 and 14 µM) mainly through quenching the fluorescence of tryptophan (Trp) residues in the pattern of dynamic quenching related to molecular diffusion. More important, resonance energy transfer from excited-state BSA to Kyn was confirmed, leading to the generation "energetic" Kyn that might be ability of hyperactivity according to the theory of photochemical reaction. These data indicate that UV irradiation is contributable for Kyn to function, and present a novel pattern of altering the activity of biomolecules to some degree.


Assuntos
Indolamina-Pirrol 2,3,-Dioxigenase , Cinurenina , Transferência de Energia , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Cinurenina/metabolismo , Cinurenina/farmacologia , Triptofano/metabolismo
6.
J Magn Reson Imaging ; 55(5): 1357-1375, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34637568

RESUMO

Over the past two decades, considerable efforts have been made to develop non-invasive methods for determining tumor grade or surrogates for predicting the biological behavior, aiding early treatment decisions, and providing prognostic information. The development of new imaging tools, such as diffusion-weighted imaging, diffusion kurtosis imaging, perfusion imaging, and magnetic resonance spectroscopy have provided leverage in the diagnosis of soft tissue sarcomas. Artificial intelligence is a new technology used to study and simulate human thinking and abilities, which can extract and analyze advanced and quantitative image features from medical images with high throughput for an in-depth characterization of the spatial heterogeneity of tumor tissues. This article reviews the current imaging modalities used to predict the histopathological grade of soft tissue sarcomas and highlights the advantages and limitations of each modality. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY: Stage 2.


Assuntos
Sarcoma , Neoplasias de Tecidos Moles , Inteligência Artificial , Imagem de Difusão por Ressonância Magnética/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos , Sarcoma/diagnóstico por imagem , Sarcoma/patologia , Neoplasias de Tecidos Moles/patologia
7.
Connect Tissue Res ; 63(6): 615-624, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35311424

RESUMO

PURPOSE: Altered joint loading by trauma induces joint degeneration, eventually leading to the generation of post-traumatic osteoarthritis (PTOA). Recent studies have shown that α2-macroglobulin (A2M) inhibits PTOA, induced by anterior cruciate ligament transection (ACLT), pathogenesis by regulating proinflammatory cytokines and matrix metalloproteinases. However, the application of A2M is limited due to high prices. Therefore, the aim of this study is to explore the novel preparation of A2M. MATERIALS AND METHODS: The early change of A2M in synovial fluid and serum was measured by ELISA. Ultra-filtered centrifugation was performed to prepare α2-macroglobulin-rich serum (A2MRS). The bioactivity of A2M in A2MRS was detected by improved Ellis and Gollas-Galvan method. The effects of A2MRS on PTOA were observed using immunohistochemistry, safranine O staining, micro X-ray, fluorescence molecular tomography etc. RESULTS: The concentration of A2M in PTOA group was significantly higher than that in Sham group in synovial fluid on the third day after ACLT in rat PTOA model. On the contrary, a significant downregulation of A2M levels in PTOA group was observed compared to the Sham group in serum at the seventh day after ACLT. Secondly, A2MRS was prepared successfully, and the concentration and bioactivity of A2M in A2MRS was significantly higher than that in serum. Lastly, A2MRS not only reduced notably the production of secondary cartilage ossification, type 10 collagen and matrix metalloproteinase 13, but also increased profoundly the generation of type 2 collagen, aggrecan, and chondrocytes' number. CONCLUSION: Our results indicate that A2MRS has protective effects on PTOA.


Assuntos
Lesões do Ligamento Cruzado Anterior , Cartilagem Articular , Osteoartrite , alfa 2-Macroglobulinas Associadas à Gravidez , Animais , Feminino , Gravidez , Ratos , Agrecanas/farmacologia , Cartilagem Articular/patologia , Citocinas , Modelos Animais de Doenças , Metaloproteinase 13 da Matriz , Osteoartrite/tratamento farmacológico , Osteoartrite/etiologia , Osteoartrite/patologia , alfa 2-Macroglobulinas Associadas à Gravidez/farmacologia , Lesões do Ligamento Cruzado Anterior/tratamento farmacológico , Lesões do Ligamento Cruzado Anterior/patologia
8.
J Bone Miner Metab ; 40(1): 9-19, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34524525

RESUMO

INTRODUCTION: Enoxaparin is widely used to prevent venous thromboembolism after orthopedic surgery and has some adverse effects, such as osteoporosis and delay in fracture healing. However, the exact mechanism delaying bone healing by enoxaparin is still unclear. MATERIALS AND METHODS: X-ray and Micro-CT scanning were performed to detect the effects of enoxaparin on bone healing at rat model of bone defeat. CCK-8 assay and flow cytometry were conducted to measure the effects of enoxaparin on bone marrow mesenchymal stem cells (BMSCs). The mRNA/protein levels of osteocalcin (OCN), runt-related transcription factor 2 (Runx2) and bone morphogenetic protein 2 (BMP2) were analyzed by real-time PCR and western blotting, respectively. Alizarin red staining was used to observe the mineralized nodules. RESULTS: Enoxaparin (2000 AXaIU/kg) not only profoundly increased the trabecular separation, but also notably decreased the trabecular bone volume/tissue volume, trabecular thickness, trabecular number and OCN level, in vivo. Additionally, significantly inhibiting proliferation of BMSCs by enoxaparin (1.0 and 10 AXaIU/ml) was detected. The apoptosis and the ratio of G phase cells in enoxaparin (0.1, 1.0 and 10 AXaIU/ml) group were obviously higher than that in control group. While the ratio of S phase cells was downregulated markedly by enoxaparin (0.1,1.0 and 10 AXaIU/ml) compared with the control group. Most importantly, inducing significant decreases of OCN/Runx2 mRNA/protein expression and formation of mineralized nodules by enoxaparin (0.1, 1.0 and 10 AXaIU/ml) were observed compared with the control group. While the notable decreases of BMP2 mRNA/protein level were only detected in enoxaparin (10 AXaIU/ml) group. CONCLUSION: It was suggested that enoxaparin impaired bone healing through suppressing the differentiation of BMSCs towards osteoblasts.


Assuntos
Enoxaparina , Células-Tronco Mesenquimais , Animais , Células da Medula Óssea , Diferenciação Celular , Células Cultivadas , Enoxaparina/farmacologia , Osteoblastos , Osteogênese , Ratos , Ratos Sprague-Dawley
9.
J Bone Miner Metab ; 37(4): 711-721, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30465089

RESUMO

The dysregulated expression of the osteoarthritis (OA)-related genes in cartilage, such as matrix metalloproteinase 13 (MMP-13) and type X collagen (Col X), facilitates the onset and progression of OA. Reduced parathyroid hormone-related protein (PTHrP) may also accelerate this progression. Furthermore, miRNAs, endogenous regulators of mRNAs, are thought to play key roles in the pathogenesis of OA. In this study, we found that miR-195 levels were significantly upregulated in OA tissue, while PTHrP mRNA/protein expression was substantially downregulated, and there was a negative correlation between miR-195 and PTHrP. Upregulated miR-195 strongly inhibited Aggrecan, type II collagen (Col II) mRNA/protein expression, while it enhanced the expression of MMP-13 and Col X at mRNA/protein level; conversely, downregulated miR-195 significantly increased Col II mRNA/protein expression, while it decreased the expression of MMP-13 and Col X mRNA/protein. Moreover, our study demonstrated that PTHrP is a novel target of miR-195 using dual luciferase reporter assay. Finally, miR-195-mediated changes of Col II and OA-related genes were substantially attenuated by siRNAPTHrP treatment. These results suggested that miR-195 is involved in the pathogenesis of OA via PTHrP.


Assuntos
MicroRNAs/metabolismo , Osteoartrite/genética , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Idoso , Sequência de Bases , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Estudos de Casos e Controles , Células Cultivadas , Condrócitos/metabolismo , Condrócitos/patologia , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Proteína Relacionada ao Hormônio Paratireóideo/genética
10.
Mol Cell Biochem ; 448(1-2): 165-173, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29442266

RESUMO

Epithelial-to-mesenchymal transition (EMT) is believed to play key roles in the process of cancer metastasis. The molecular changes during EMT are characterized by the down-regulation of epithelial proteins, such as E-cadherin, and the up-regulation of mesenchymal proteins, such as vimentin (VIM). It has been demonstrated that L-kynurenine (L-Kyn), a physiological ligand of Aryl hydrocarbon receptor (Ahr), promotes cancer cells to metastasize. However, the effects of D-enantiomer of kynurenine, D-kynurenine (D-Kyn), on metastasis are still unclear. In the present paper, we firstly confirmed that D-Kyn (10, 40, 60, and 100 µM) positively regulated the metastasis of 95D cells, a lung cancer cell line, which was reduced upon siRNAAhr treatment. Moreover, significant enhancement VIM expression was detected in the presence of D-Kyn (10 and 40 µM). In contrast, 10 µM D-Kyn markedly attenuated E-cadherin level. Additionally, 10 µM D-Kyn-mediated changes of VIM and E-cadherin were substantially attenuated on siRNAAhr treatment as well. Most importantly, the evidences-10/40 µM D-Kyn-induced up-regulation of CYP1A1, 10 µM D-Kyn-induced increase of nuclear transfer of Ahr, and 10/40/60/100 µM D-Kyn-induced enhancement of DER-luciferase activity-indicated that D-Kyn was capable of activating Ahr in fact. These results suggest that D-Kyn increases lung cancer cells to metastasize by activating Ahr.


Assuntos
Transição Epitelial-Mesenquimal/efeitos dos fármacos , Cinurenina/farmacologia , Neoplasias Pulmonares/metabolismo , Proteínas de Neoplasias/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Caderinas/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Metástase Neoplásica , Vimentina/metabolismo
11.
Int J Mol Sci ; 17(4): 411, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-27092487

RESUMO

Cross-linked hyaluronic acid hydrogel (cHA gel) and dexamethasone (Dex) have been used to treat knee osteoarthritis (OA) in clinical practice owing to their chondroprotective and anti-inflammatory effects, respectively. The aim of the present study was to compare the treatment effects of the cHA gel pre-mixed with/without Dex in a surgery-induced osteoarthritis model in rats. Anterior cruciate ligament transection (ACLT) surgery was performed on the right knee of rats to induce OA. Male 2-month-old Sprague-Dawley rats were randomly divided into five groups (n = 10/per group): (1) ACLT + saline; (2) ACLT + cHA gel; (3) ACLT + cHA-Dex (0.2 mg/mL) gel; (4) ACLT + cHA-Dex (0.5 mg/mL) gel; (5) Sham + saline. Intra-joint injections were performed four weeks after ACLT in the right knee. All animals were euthanized at 12 weeks post-surgery. Cartilage damage and changes in the synovial membrane were assessed by micro X-ray, Indian ink articular surface staining, Safranin-O/Fast Green staining, immunohistochemistry, hematoxylin and eosin staining of the synovial membrane, and quantitative reverse transcription-polymerase chain reaction for changes in gene expression. Micro X-ray revealed that the knee joint treated with the cHA-Dex gel was wider than those treated with cHA gel alone or saline. The cHA-Dex gel group had less Indian ink staining (indicator of cartilage fibrillation) than the cHA gel or saline injection groups. Safranin-O/Fast Green staining indicated that increased proteoglycan staining and less cartilage damage were found in the cHA-Dex gel group compared with the cHA gel or saline injection groups. Quantification of histology findings from saline, cHA gel, cHA-Dex (0.2 mg/mL) gel, cHA-Dex (0.5 mg/mL) gel, and sham groups were 5.84 ± 0.29, 4.50 ± 0.87, 3.00 ± 1.00, 2.00 ± 0.48, and 0.30 ± 0.58 (p < 0.05), respectively. A strong staining of type II collagen was found in both the cHA-Dex gel groups compared with saline group or cHA alone group. Similar result was found for the mRNA level of aggrecan and opposite result for type X collagen. Hematoxylin and eosin staining in the synovial membrane showed less synovial lining cell layers and reduced inflammatory cell infiltration in cHA-Dex gel-treated animals compared with saline or cHA only groups. Altogether, cHA-Dex gel has better chondroprotective and anti-inflammatory effects in rat surgery-induced osteoarthritis than cHA alone.


Assuntos
Anti-Inflamatórios/administração & dosagem , Dexametasona/administração & dosagem , Ácido Hialurônico/administração & dosagem , Hidrogéis/química , Osteoartrite do Joelho/tratamento farmacológico , Animais , Anti-Inflamatórios/farmacologia , Colágeno Tipo II/genética , Reagentes de Ligações Cruzadas , Dexametasona/farmacologia , Modelos Animais de Doenças , Sinergismo Farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Ácido Hialurônico/química , Ácido Hialurônico/uso terapêutico , Injeções Intra-Articulares , Articulação do Joelho/efeitos dos fármacos , Masculino , Osteoartrite do Joelho/genética , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
12.
FASEB J ; 28(10): 4381-93, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25002121

RESUMO

MicroRNAs (miRNAs), including host miRNAs and viral miRNAs, play vital roles in regulating host-virus interactions. DNA viruses encode miRNAs that regulate the viral life cycle. However, it is generally believed that cytoplasmic RNA viruses do not encode miRNAs, owing to inaccessible cellular miRNA processing machinery. Here, we provide a comprehensive genome-wide analysis and identification of miRNAs that were derived from hepatitis A virus (HAV; Hu/China/H2/1982), which is a typical cytoplasmic RNA virus. Using deep-sequencing and in silico approaches, we identified 2 novel virally encoded miRNAs, named hav-miR-1-5p and hav-miR-2-5p. Both of the novel virally encoded miRNAs were clearly detected in infected cells. Analysis of Dicer enzyme silencing demonstrated that HAV-derived miRNA biogenesis is Dicer dependent. Furthermore, we confirmed that HAV mature miRNAs were generated from viral miRNA precursors (pre-miRNAs) in host cells. Notably, naturally derived HAV miRNAs were biologically and functionally active and induced post-transcriptional gene silencing (PTGS). Genomic location analysis revealed novel miRNAs located in the coding region of the viral genome. Overall, our results show that HAV naturally generates functional miRNA-like small regulatory RNAs during infection. This is the first report of miRNAs derived from the coding region of genomic RNA of a cytoplasmic RNA virus. These observations demonstrate that a cytoplasmic RNA virus can naturally generate functional miRNAs, as DNA viruses do. These findings also contribute to improved understanding of host-RNA virus interactions mediated by RNA virus-derived miRNAs.


Assuntos
Vírus da Hepatite A/genética , Hepatite A/metabolismo , MicroRNAs/metabolismo , RNA Viral/metabolismo , Sequência de Bases , Linhagem Celular , Inativação Gênica , Vírus da Hepatite A/metabolismo , Humanos , MicroRNAs/química , MicroRNAs/genética , Dados de Sequência Molecular , Precursores de RNA/genética , Precursores de RNA/metabolismo , RNA Viral/química , RNA Viral/genética , Ribonuclease III/genética , Ribonuclease III/metabolismo
13.
Virol J ; 11: 121, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24981144

RESUMO

BACKGROUND: It is generally believed that RNA virus replicating in the cell cytoplasm would not encode microRNAs (miRNAs) due to nucleus inaccessibility. Recent studies have described cytoplasmic RNA virus genome-derived miRNAs in West Nile virus (WNV) and Dengue virus (DENV). However, naturally occurring miRNAs derived from the antigenome of a cytoplasmic RNA virus have not been described. METHODS: Hepatitis A virus (HAV) was served as a model virus to investigate whether the antigenome of a cytoplasmic RNA virus would be processed into miRNAs or miRNA-like small RNAs upon infection. HAV antigenome was queried for putative miRNA precursors (pre-miRNA) with the VMir analyzer program. Mature miRNA prediction was performed using MatureBayes and Bayes-SVM-MiRNA web server v1.0. Finally, multiple experimental approaches, including cloning and sequencing-, RNAi-, plasmid-based miRNA expression- and luciferase reporter assays, were performed to identify and validate naturally occurring viral antigenome-derived miRNAs. RESULTS: Using human HAV genotype IA (isolate H2) (HAVH2), a virally encoded miRNA-like small RNA was detected on the antigenome and named hav-miR-N1-3p. Transcription of viral pre-miRNA in KMB17 and HEK293T cells led to mature hav-miR-N1-3p production. In addition, silencing of the miRNA-processing enzyme Dicer or Drosha caused a dramatic reduction in miRNA levels. Furthermore, artificial target of hav-miR-N1-3p was silenced by synthesized viral miRNA mimics and the HAVH2 naturally-derived hav-miR-N1-3p. CONCLUSION: These results suggested that the antigenome of a cytoplasmic RNA virus could be processed into functional miRNAs. Our findings provide new evidence supporting the hypothesis that cytoplasmic RNA viruses naturally encode miRNAs through cellular miRNA processing machinery.


Assuntos
Genoma Viral , Vírus da Hepatite A/genética , MicroRNAs/genética , RNA Viral/genética , Linhagem Celular , Biologia Computacional , Humanos , MicroRNAs/metabolismo , RNA Viral/metabolismo
14.
Small Methods ; 8(1): e2301003, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37882344

RESUMO

The strategy of combining different semiconductor materials is adjudged an effective approach to improve the sensing performances of semiconductor materials. However, the specific synergistic mechanism for the excellent gas-sensitive performances of composite materials has not been elucidated. Herein, a facile solvothermal method is employed to synthesize SnX Ti1-X O2 -TiX Sn1-X O2 core-shell heterostructures using SnCl4 •5H2 O and tetrabutyl titanate (TBOT) as raw materials. When the molar ratio of SnCl4 •5H2 O/TBOT is 1.8/3.0, the afforded composite exhibited the highest gas sensing performances compared with other composites prepared with other molar ratios. The enhanced sensing performance is attributed to the simultaneous incorporation of Sn and Ti ions into each other's lattice, leading to an increase in the density of unsaturated Sn and Ti atoms on the surface. Ultimately, more oxygen vacancies are formed by the unsaturated Sn and Ti atoms, which benefits electron capture and the redox reaction of adsorbed gases. Thus, the concept of increased unsaturated metal atoms and oxygen vacancy resulting from the doping of different metal ions into each other's lattice has deepened the understanding of gas sensing and the catalytic reaction mechanisms. The lattice synergy of different metals provides a pathway for the design of advanced gas-sensing materials and catalysts.

15.
Acad Radiol ; 31(3): 1014-1023, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37714721

RESUMO

RATIONALE AND OBJECTIVES: To investigate whether intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) parameters correlate with hypoxia biomarkers, namely hypoxia inducible factor-1ɑ (HIF-1ɑ), carbonic anhydrase IX (CAIX), and pimonidazole (PIMO), in fibrosarcoma (FS) murine models. MATERIALS AND METHODS: A model of 30 FS nude mice was established. All mice underwent magnetic resonance imaging (MRI) scans after which the IVIM (standard apparent diffusion coefficient [standard ADC], pure diffusion coefficient [D], pseudo-diffusion coefficient [D*], and perfusion fraction [f]) and DKI parameters (mean diffusion [MD], mean kurtosis [MK]) were obtained. Based on an MRI-pathology controlled method, correlations between each MRI parameter and hypoxia biomarkers were assessed by Pearson or Spearman tests. An independent sample t-test or Wilcoxon's rank sum test, and receiver operating characteristic curves were used to identify whether MRI parameters could differentiate between high and low expressions of hypoxia biomarkers. RESULTS: The IVIM/DKI parameters showed varying degrees of correlation with HIF-1α, CAIX, and PIMO expression. Among them, the D, f, and MK values could confirm HIF-1α expression, while D, f, and MK values could assess CAIX expression. Finally, standard D and MK values could evaluate PIMO expression levels. CONCLUSION: IVIM and DKI parameters can be used to reflect hypoxic biomarkers of FS and have the potential to detect tumor hypoxia.


Assuntos
Fibrossarcoma , Imageamento por Ressonância Magnética , Animais , Camundongos , Camundongos Nus , Imageamento por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Biomarcadores , Movimento (Física) , Fibrossarcoma/diagnóstico por imagem
16.
Acad Radiol ; 30(10): 2299-2308, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-36481126

RESUMO

RATIONAL AND OBJECTIVE: To explore the correlations of histogram parameters from diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) with the heterogeneous features in a nude mouse model of fibrosarcoma. MATERIALS AND METHODS: A total of 44 fibrosarcoma xenograft models were established by inoculating HT-1080 cells on the right thigh of mice and subjected tumors to DWI and IVIM imaging with 3.0 T MRI. Whole-tumor histogram parameters were calculated on apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f). Heterogeneous features, including necrosis rate, cell density, Ki-67 labeling index (LI), and microvascular density (MVD) were measured. Intraclass correlation coefficients (ICC), Pearson or Spearman correlation tests, and receiver operating characteristics (ROC) were performed. RESULTS: The 90th percentile, skewness and kurtosis of ADC and D histograms showed correlations with necrosis rate, and the highest correlation coefficient was found for D90th (r = 0.485). ADC and D histogram parameters showed correlations with cell density and Ki-67 LI; D90th showed the highest correlation coefficient with cell density (r = -0.504); and Dmedian showed the most significant correlation with Ki-67 LI (r = -0.525). D*skewness, D*kurtosis, D*90th, fmean, and fmedian showed correlations with MVD. ADC90th, ADCskewness, ADCkurtosis, D90th, and Dskewness showed significant differences between the low necrosis and high necrosis groups, and the combination model showed the best diagnostic ability (AUC = 0.882), with 97% sensitivity, and 72.7% specificity. CONCLUSION: Whole-tumor histogram parameters of DWI and IVIM were correlated with heterogeneous features in nude murine models of fibrosarcoma.


Assuntos
Imagem de Difusão por Ressonância Magnética , Fibrossarcoma , Humanos , Animais , Camundongos , Xenoenxertos , Antígeno Ki-67 , Imagem de Difusão por Ressonância Magnética/métodos , Necrose , Fibrossarcoma/diagnóstico por imagem , Movimento (Física)
17.
Transl Oncol ; 20: 101414, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35397420

RESUMO

OBJECTIVE: This review investigates the role of adjuvant therapy (AT) and the importance of histopathological typing in periampullary carcinoma (PAC) treatment. BACKGROUND: PAC is a relatively rare gastrointestinal malignancy. The regimen and effect of AT in PAC are still controversial. However, there is a treatment based on histopathological types (pancreaticobiliary-type, PB-type or intestinal-type, IN-type), but there are no clear guidelines indicating that typing can be used to guide the selection of AT drugs. METHODS: A literature search of PubMed and Web of Science databases was conducted for studies published from January 2001 to August 2021 on the use of AT in PAC. RESULTS: A total of 75 studies were included in this review. According to existing studies, AT for PAC is mostly based on 5-FU or gemcitabine, but the effect is unknown. However, when PAC is classified into different histopathological types, AT with gemcitabine is beneficial for patients with the PB-type of PAC, while 5-FU-based AT is beneficial for patients with the IN-type of PAC. In addition, the benefits of AT are more pronounced in patients with a high-risk disease, such as patients with stage II/III, T3/T4 tumors, or positive lymph node involvement. There are few studies on targeted therapy and immunotherapy for PAC. CONCLUSIONS: This review suggests that AT has potential survival benefits, especially when based on the histopathologic type that helps the choice of drugs during AT in PAC patients.

18.
Gland Surg ; 11(8): 1395-1403, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36082089

RESUMO

Background: Pancreaticoduodenectomy (PD) is the main curative treatment for periampullary carcinoma (PAC), but the high risk of complications in PD means an accurate preoperative diagnosis is essential, because benign lesions can be treated without PD. Despite as the preferred diagnosis method, preoperative endoscopic biopsy is characterized with high false-negative rate, which disturbs the making of surgical plans. We explored the degree of matching between preoperative and postoperative pathological diagnoses, analyzed the shortcomings of endoscopic biopsy, and provide recommendations for the diagnosis and treatment of periampullary tumors. Methods: We retrospectively analyzed 198 patients with periampullary tumors who underwent endoscopic biopsy and PD between June 2013 and February 2021. Data on disease characteristics, such as sex, age, total bilirubin (TBIL), direct bilirubin (DBIL), tumor markers, imaging features, preoperative and postoperative pathology were collected and reviewed. The measurement data with normal distribution were expressed by mean ± standard deviation, and the categorical data were expressed by the number of cases. Results: In our cohort, 196 patients (98.99%) were diagnosed with PAC based on postoperative pathology. Preoperative pathological biopsy was performed in 198 patients with dysplasia (n=76), inflammation (n=7), and PAC (n=115), among whom 111 were diagnosed with PAC at the first biopsy and 4/7 at the second biopsy. The false-negative rate for one preoperative biopsy was 85/196 (43.37%); 74/76 (97.37%) patients in the dysplasia subgroup and 7/7 (100%) patients in the inflammation subgroup showed malignant results after surgery. Conclusions: Preoperative endoscopic biopsy has a high false-negative rate. Multiple sites, greater depth, and more biopsies may increase accuracy. Patients preoperatively diagnosed with dysplasia have a high risk for cancer and are recommended to undergo PD directly.

19.
Nanomaterials (Basel) ; 12(14)2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35889602

RESUMO

Carbon dots (CDs) have caught enormous attention owing to their distinctive properties, such as their high water solubility, tunable optical properties, and easy surface modification, which can be generally used for the detection of heavy metals and organic pollutants. Herein, nitrogen and fluorine co-doped carbon dots (NFCDs) were designed via a rapid, low-cost, and one-step microwave-assisted technique using DL-malic acid and levofloxacin. The NFCDs emitted intense green fluorescence under UV lighting, and the optical emission peak at 490 nm was observed upon a 280 nm excitation, with a high quantum yield of 21.03%. Interestingly, the spectral measurements illustrated excitation-independent and concentration-independent single-color fluorescence owing to the presence of nitrogen and fluorine elements in the surface functional groups. Additionally, the NFCDs were applied for the selective detection of Fe3+ and ascorbic acid based on the "turn-off" mode. The detection limits were determined as 1.03 and 4.22 µM, respectively. The quenching mechanisms were explored using the static quenching mechanism and the inner filter effect. Therefore, a NFCDs fluorescent probe with single color emission was successfully developed for the convenient and rapid detection of Fe3+ and ascorbic acid in environments.

20.
Front Pharmacol ; 13: 849102, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36133821

RESUMO

Post-traumatic osteoarthritis is a special type of osteoarthritis and a common disease, with few effective treatments available. α2-Macroglobulin (α2M) is important to chondral protection in post-traumatic osteoarthritis. However, its injection into xenogeneic joint cavities involves safety hazards, limiting clinical applications. Exploring serum α2M-enriching strategies and the therapeutic effect and mechanism of α2M-rich serum (α2MRS) autologous joint injection to treat post-traumatic osteoarthritis has significant value. In the present study, a unique filtration process was used to obtain α2MRS from human and mini pig serum. We evaluated the potential of α2MRS in protecting against post-surgery cartilage degeneration. We identify the potential of α2MRS in reducing the expression of inflammatory cytokines and factors that hasten cartilage degeneration in post-operative conditions leading to post-traumatic osteoarthritis. The potential of α2MRS was analyzed in interleukin-1ß induced human chondrocytes and mini pig models. In the chondrocyte model, α2MRS significantly promoted human chondrocyte proliferation and reduced apoptosis and chondrocyte catabolic cytokine gene transcription and secretion. The anterior cruciate ligament autograft reconstruction model of mini pigs was randomized into groups, operated on, and injected with α2MRS or saline. The results showed that α2MRS injection significantly suppressed the levels of inflammatory factors, improved gait, and showed significantly lower cartilage degeneration than the groups that did not receive α2MRS injections. This study highlights the chondroprotective effects of α2MRS, elucidated its potential applications against cartilage degeneration, and could provide a basis for the clinical translation of α2MRS.

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