Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 121(43): e2308684121, 2024 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-39388277

RESUMO

The aqueous alteration of the oceanic lithosphere provides significant energy that impacts the synthesis and diversity of organic compounds, which are crucial for the deep carbon cycle and may have provided the first building blocks for life. Although abiotic organic synthesis has been documented in mantle-derived rocks, the formation mechanisms and complexity of organic compounds in crustal rocks remain largely unknown. Here, we show the specific association of aliphatic carbonaceous matter with Fe oxyhydroxides in mafic crustal rocks of the Southwest Indian Ridge (SWIR). We determine potential Fe-based pathways for abiotic organic synthesis from CO2 and H2 using multimodal and molecular nano-geochemical tools. Quantum mechanical modeling is further employed to constrain the catalytical activity of Fe oxyhydroxides, revealing that the catalytic cycle of hydrogen may play a key role in carbon-carbon bond formation. This approach offers the possibility of interpreting physicochemical organic formation and condensation mechanisms at an atomic scale. The findings expand our knowledge of the existence of abiotic organic carbon in the oceanic crustal rocks and emphasize the mafic oceanic crust of the SWIR as a potential site for low-temperature abiotic organic synthesis.

2.
Eur Radiol ; 33(6): 3995-4006, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36571604

RESUMO

OBJECTIVES: To comprehensively assess osteoporosis in the lumbar spine, a compositional MR imaging technique is proposed to quantify proton fractions for all the water components as well as fat in lumbar vertebrae measured by a combination of a 3D short repetition time adiabatic inversion recovery prepared ultrashort echo time (STAIR-UTE) MRI and IDEAL-IQ. METHODS: A total of 182 participants underwent MRI, quantitative CT, and DXA. Lumbar collagen-bound water proton fraction (CBWPF), free water proton fraction (FWPF), total water proton fraction (TWPF), bone mineral density (BMD), and T-score were calculated in three vertebrae (L2-L4) for each subject. The correlations of the CBWPF, FWPF, and TWPF with BMD and T-score were investigated respectively. A comprehensive diagnostic model combining all the water components and clinical characteristics was established. The performances of all the water components and the comprehensive diagnostic model to discriminate between normal, osteopenia, and osteoporosis cohorts were also evaluated using receiver operator characteristic (ROC). RESULTS: The CBWPF showed strong correlations with BMD (r = 0.85, p < 0.001) and T-score (r = 0.72, p < 0.001), while the FWPF and TWPF showed moderate correlations with BMD (r = 0.65 and 0.68, p < 0.001) and T-score (r = 0.47 and 0.49, p < 0.001). The high area under the curve values obtained from ROC analysis demonstrated that CBWPF, FWPF, and TWPF have the potential to differentiate the normal, osteopenia, and osteoporosis cohorts. At the same time, the comprehensive diagnostic model shows the best performance. CONCLUSIONS: The compositional MRI technique, which quantifies CBWPF, FWPF, and TWPF in trabecular bone, is promising in the assessment of bone quality. KEY POINTS: • Compositional MR imaging technique is able to quantify proton fractions for all the water components (i.e., collagen-bound water proton fraction (CBWPF), free water proton fraction (FWPF), and total water proton fraction (TWPF)) in the human lumbar spine. • The biomarkers derived from the compositional MR imaging technique showed moderate to high correlations with bone mineral density (BMD) and T-score and showed good performance in distinguishing people with different bone mass. • The comprehensive diagnostic model incorporating CBWPF, FWPF, TWPF, and clinical characteristics showed the highest clinical diagnostic capability for the assessment of osteoporosis.


Assuntos
Doenças Ósseas Metabólicas , Osteoporose , Humanos , Vértebras Lombares/diagnóstico por imagem , Osso Esponjoso/diagnóstico por imagem , Prótons , Osteoporose/diagnóstico por imagem , Densidade Óssea , Imageamento por Ressonância Magnética/métodos , Água , Colágeno , Absorciometria de Fóton/métodos
3.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 47(4): 516-521, 2016 Jul.
Artigo em Zh | MEDLINE | ID: mdl-28591953

RESUMO

OBJECTIVES: To investigate the biodistribution of superparamagnetic iron oxide (SPIO)-shRNA molecular probe by magnetic resonance imaging (MRI) in vivo. METHODS: Six New Zealand white rabbits were injected intravenously with SPIO-shRNA molecular probe (9.6 mg Fe/kg) via ear edge vein. The blood samples were collected to analyse the pharmacokinetic parameters through measuring the iron content by atomic absorption spectrometry (AAS) method at 30 min before and 1 min, 3 min, 5 min, 10 min, 15 min, 30 min and at 1, 2, 3, 6, 12, and 24 h after the injection. Six Kun Ming (KM) mice were injected intravenously with SPIO-shRNA molecular probe (4.8 mg Fe/kg). The biodistribution of SPIO-shRNA molecular probe was traced by MRI in vivo. Ninety six KM mice were randomly divided into control group and experimental group: each mouse in experimental group was injected intravenously with SPIO-shRNA molecular probe (4.8 mg Fe/kg). The liver, spleen, kidney, brain and muscle of the control group and the experimental group on 1, 3, 5, 7, 9, 11 and 14 d after the injection were collected. The organ iron content were measured by AAS method and Prussian blue staining in order to observe the distribution of the SPIO-shRNA molecular probe in the main organ. RESULTS: Our results demonstrated that the pharmacokinetics of the molecular probe complied with two-compartment model, and the blood half-life was (3.692±0.196) h. The data of MRI showed that the probe were distributed in liver and spleen, and the signs were reduced in accord with the increase of probe's doses in liver and spleen. The probe's metabolism was slow, and the probe was cleared from liver and spleen at 2 weeks after the injection. The results of AAS and Prussian blue staining further testified the results of MRI. CONCLUSIONS: Our data showed the biodistribution of SPIO-shRNA molecular probe in main organs can be traced by MRI in vivo. Meanwhile, it provides important information for the effectiveness of the probe by MRI at tumor in vivo.


Assuntos
Imageamento por Ressonância Magnética , Nanopartículas de Magnetita/análise , Sondas Moleculares/farmacocinética , RNA Interferente Pequeno/farmacocinética , Animais , Meios de Contraste , Dextranos , Compostos Férricos , Camundongos , Coelhos , Distribuição Tecidual
4.
Tumour Biol ; 36(4): 2747-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25487615

RESUMO

The cancer stem cell (CSC) theory states that many types of cancer, including nasopharyngeal cancer (NPC), are initiated from and maintained by CSCs, which may be responsible for tumor relapse and resistance to therapy. It is imperative that nasopharyngeal cancer stem cells (NPCSCs) be specifically targeted to eradicate NPC and prevent recurrence. Epigallocatechin-3-gallate (EGCG) inhibits cancer progression by attenuating NF-κB p65 activity, which is upregulated in CSCs and plays an important role in epithelial-mesenchymal transition (EMT). The purpose of this study is to confirm the self-renewal and migration inhibitory effects of EGCG toward NPCSCs and to clarify its mechanism of activity. We enriched and characterized NPCSCs by collecting spheroid-derived cells grown in serum-free medium (SFM) and examined the effects of EGCG on the characteristics of NPCSCs and studied the underlying mechanisms using soft agar colony assays, transwell migration assays, reverse transcriptase polymerase chain reaction (RT-PCR), Western blot analysis, immunofluorescence staining, and xenograft studies. NPC spheroids enriched from NPC cell lines acquired CSC traits and underwent EMT. EGCG inhibited the NPCSCs' self-renewal and migration and reversed EMT, and combined treatment with EGCG and cisplatin reduced the growth of CSC tumor xenografts. Moreover, EGCG inhibited NF-κB p65 activity by modulating the cellular localization of p65 and decreasing the transcriptional regulation of NF-κB p65 on Twist1 expression. NF-κB p65 is a novel therapeutic target in NPCSCs, and the inhibition of activated NF-κB p65 in CSCs by EGCG may offer an effective treatment for NPC.


Assuntos
Proteínas de Transporte/genética , Catequina/análogos & derivados , Neoplasias Nasofaríngeas/tratamento farmacológico , Proteínas de Neoplasias/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Proteínas de Transporte/antagonistas & inibidores , Catequina/administração & dosagem , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Transição Epitelial-Mesenquimal , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , NF-kappa B/genética , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Proteínas de Neoplasias/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
5.
Mol Cell Biochem ; 409(1-2): 113-22, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26188800

RESUMO

Many recent studies have suggested that bergapten (BP), a class of native compound with numerous biological activities such as anti-resorptive properties, may exert protective effects against postmenopausal bone loss. However, it remains unknown whether BP regulates or improves the osteogenic function of bone marrow stromal cells (BMSCs) in the treatment and prevention of osteoporosis. In our study, BMSCs were cultured in osteogenic induction medium with the addition of BP for 2 weeks and an ovariectomized mouse model of osteoporosis was used to investigate the anti-resorptive effect of BP by gavage administration for 3 months. The concentrations of BP used were 0.1, 1, and 10 µmol/L in vitro and the gavage dose was 20 mg/kg/d. The result of our study indicated that BP promotes the expression of alkaline phosphatase (ALP) by BMSCs in vitro in a dose-dependent manner, as revealed by ALP staining. Runt-related transcription factor 2 and osteocalcin were up-regulated both in vitro and vivo, while osterix and collagen Iα1, assessed by immunofluorescence and immunohistochemistry, were correspondingly raised in the presence of BP in BMSCs in vitro. In addition, a protective effect of BP against ovariectomy-induced bone loss was found by distal femur micro-CT scanning, with improvements of bone metabolism parameters such as bone mineral density, trabecular number, and trabecular separation. Furthermore, WNT/ß-catenin signaling was activated in the presence of BP in BMSCs in osteogenic culture. Finally, BP promoted differentiation of BMSCs into osteoblasts by up-regulation of the WNT/ß-catenin pathway.


Assuntos
Células-Tronco Mesenquimais/citologia , Metoxaleno/análogos & derivados , Osteoblastos/citologia , Osteogênese/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , 5-Metoxipsoraleno , Fosfatase Alcalina/biossíntese , Animais , Células da Medula Óssea/citologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo I/biossíntese , Subunidade alfa 1 de Fator de Ligação ao Core/biossíntese , Feminino , Metoxaleno/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Osteocalcina/biossíntese , Osteoporose/patologia , Fator de Transcrição Sp7 , Fatores de Transcrição/biossíntese , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
6.
Eur Radiol ; 25(9): 2754-63, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25678080

RESUMO

OBJECTIVE: To confirm feasibility and assess intravoxel incoherent motion (IVIM) to differentiate active sacroiliitis and ankylosing spondylitis.. METHODS: Forty-one patients were divided into two groups, an active group (n = 20) and a chronic group (n = 21), according to the Bath Ankylosing Spondylitis (AS) Disease Activity Index (BASDAI) and laboratory parameters. In addition, 21 healthy volunteers were chosen as the control group. Tissue diffusivity (Dslow), perfusion fraction (f), and pseudo-diffusion coefficient (Dfast) values were obtained for all three groups. One-way analysis of variance and receiver operating characteristic analysis were performed for all parameters. RESULTS: There was good interobserver agreement on the measurements between the two observers. The optimal cut-off values (with respective AUC, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio) between active and chronic groups were Dslow = 0.53 × 10(-3) mm(2)/s (0.976, 90%, 95.2%, 18.9, 0.10) and f = 0.09 (0.545, 20%, 95.5%, 4.2, 0.84), and between chronic and control groups were Dslow = 0.22 × 10(-3) mm(2)/s (0.517, 9.52%, 100%, no number, 0.9) and f = 0.09 (0.935, 95.24%, 80.95%, 5, 0.059). CONCLUSION: Dslow and f of IVIM diffusion-weighted (DW)-MRI in AS show a significant difference in the values of diffusion of water molecules and fractional perfusion-related volume among the three groups. KEY POINTS: • D slow can be used to differentiate the activity of AS. • With perfusion fraction, the sensitivity of differentiating the AS activity is improved. • IVIM DWI plays an important role in detecting the activity in patients with AS.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Articulação Sacroilíaca/patologia , Sacroileíte/diagnóstico , Espondilite Anquilosante/diagnóstico , Adolescente , Adulto , Análise de Variância , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
7.
Beijing Da Xue Xue Bao Yi Xue Ban ; 47(5): 754-60, 2015 Oct 18.
Artigo em Zh | MEDLINE | ID: mdl-26474611

RESUMO

OBJECTIVE: To explore the effects of superparamagnetic iron oxide-short hairpin RNA (SPIO-ShRNA) dual functional molecular probes of different concentrations on morphology and biological behavior of ovarian cancer SKOV3 cells in vitro. METHODS: The dual functional molecular probes at an iron concentration of 5, 15, 30, 45, 75, and 100 mg/L were transfected into SKOV3 cells. The transfection rate of the probe was observed by fluorescence microscope. The distribution and content of iron particles in SKOV3 cells were determined by Prussian blue staining, atomic adsorption spectrometer and electron microscopy. Cell viability was observed by cell counting kit-8 (CCK-8).The apoptosis was detected by flow cytometry. The expression of protein within the cells was detected by Western blot. The changes of the signal intensity were measured by magnetic resonance imaging (MRI). RESULTS: The SPIO-ShRNA dual functional molecular probe was uptaken in aconcentration-dependence manner within a certain range (5-30 mg/L). When the concentration of the probe was 45 mg/L, the labeling rate of the cell was close to 100%; With the increase of the concentration of probe, the cell survival rate decreased gradually. The cell survival rate of each experimental group were 94.626%±1.050%, 93.373%±1.180%, 91.700%±3.122%, 75.100%±4.362%, 72.983%±3.233%, 71.010%±2.910%,5, 15, 30 mg/L cell survival rate was not significantly decreased, the difference was not statistically significant (P=0.226, P=0.068, P=0.475); When the concentration of the probe was greater than or equal to 45 mg/L,the survival rate decreased obviously (P<0.001); Group of 45 mg/L protein expression rate was 68.905%±3.510%, When the concentration of the probe was greater than or equal to 45 mg/L, the inhibition rate of the protein expression level of epidermal growth factor receptor was obviously higher than those of 5, 15, and 30 mg/L groups, the difference was statistically significant (P<0.001, P=0.001, P=0.003, all P<0.01); the MRI displayed that the signal intensity was decreased with increasing concentrations of the probe. The signal intensity of 45 mg/L group was 165.55±4.92, compared with the blank control group(same volume of phosphate buffer saline), normal group (unlabeled ovarian cancer SKOV3 cells), 5, 15, and 30 mg/L groups , the signal intensity of 45 mg/L group decreased significantly (all P<0.001). CONCLUSION: The dual functional molecular probe can effectively transfect and specifically inhibit the expression of SKOV3 cell lines at the iron concentration of 45 mg/L, and can also be detected by MRI. The role of diagnosis and treatment of the dual functional molecular probe has been initially confirmed.


Assuntos
Sondas Moleculares , Neoplasias Ovarianas/genética , RNA Interferente Pequeno , Transfecção , Apoptose , Linhagem Celular Tumoral , Sobrevivência Celular , Dextranos , Feminino , Humanos , Nanopartículas de Magnetita
8.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 37(1): 12-6, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25676264

RESUMO

OBJECTIVE: To explore the transfection rate of SPIO-shRNA dual functional molecular probe into ovarian carcinoma SKOV3 cells in external magnetic field. METHODS: Dual functional molecular probe at an iron concentration of 45 mg/L was transfected into SKOV3 cells. The cells with coexisting probe and magnetic fields were set as the intervention group,the probe-transfected cells as negative control group, and normally cultured SKOV3 without any transfection as blank control group. The transfection rate was detected by flow cytometry. Cell viability was observed by CCK-8 assay. Epidermal growth factor receptor (EGFR) expression level in SKOV3 cells was determined by real-time quantitative PCR and Western blot analysis. The signal intensity was measured by magnetic resonance imaging (MRI). RESULTS: The transfection rate of the intervention group was (79.20 ± 3.31)%, which was significantly higher than that of negative control group (P=0.001). Compared with the negative control group,the cell viability of the intervention group significantly decreased (P=0.011), protein and mRNA expression levels of EGFR in the intervention group were significantly decreased (both P<0.05). The signal intensity on T2(*)WI in the intervention group also significantly decreased (P=0.0004). CONCLUSION: The external magnetic field can improve the transfection efficiency SPIO-shRNA dual functional molecular probe into ovarian carcinoma SKOV3 cells.


Assuntos
Neoplasias Ovarianas , Western Blotting , Linhagem Celular Tumoral , Sobrevivência Celular , Receptores ErbB , Feminino , Citometria de Fluxo , Humanos , Técnicas In Vitro , Ferro , Campos Magnéticos , Sondas Moleculares , RNA Interferente Pequeno , Reação em Cadeia da Polimerase em Tempo Real , Transfecção
9.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 35(1): 19-23, 2013 Feb.
Artigo em Zh | MEDLINE | ID: mdl-23469785

RESUMO

OBJECTIVE: To explore the effects of the magnetic c-erbB-2 antisense probe of different concentrations on the morphology and expression of SK-Br-3 cancer cells in vitro. METHODS: Breast cancer SK-Br-3 cells were transfected for 24 h by antisense probe at an iron concentration of 5, 10, 25, 50, and 100 mg/L, respectively. The distribution and content of iron particles in SK-Br-3 cells was determined by Prussian blue staining, electron microscopy, and atomic absorption spectrometry. Cell viability was observed by trypan-blue exclusion and CCK-8 test. The protein expression of c-erbB-2 was assessed by the Western blot analysis. The changes of the signal strength were considered by magnetic resonance imaging (MRI). RESULTS: c-erbB-2 antisense probe was uptake by SK-Br-3 cells in a concentration-dependence manner within a certain range (5, 10, and the Medicine Scientific Research Project of Chongqing Health Bureau (062025)25 mg/L). When the probe concentration was 25 mg/L, iron content in cells was (18.38±0.28) pg, the cell vitality, survival, and c-erbB-2 protein expression were reduced significantly (all P<0.05), and the T2 value was lower significantly (P<0.05). However, the results of 50 mg/L or 100 mg/L group showed no significant difference with the 25 mg/L group (P>0.05). CONCLUSION: The magnetic c-erbB-2 antisense probe can effectively transfect and specifically inhibit the expression of SK-Br-3 cell lines at the iron concentration of 25 mg/L.


Assuntos
Elementos Antissenso (Genética)/genética , Neoplasias da Mama/patologia , Receptor ErbB-2/genética , Apoptose , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Magnetismo , Receptor ErbB-2/metabolismo , Transfecção
10.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 44(5): 708-12, 2013 Sep.
Artigo em Zh | MEDLINE | ID: mdl-24325095

RESUMO

OBJECTIVE: To determine the optimal time for MRI scanning of tumors in BALB/c mice using c-erbB2 antisense probe labeled with superparamagnetic iron oxide nanoparticles. METHODS: SK-Br-3 tumor-bearing BALB/c mice (n= 30) were injected with antisense probe (12.0 mg Fe/kg). MRI scanning was performed on 5 mice before the injection and 60 min, 180 min, 360 min, 720 min and 1 440 min after the injection, respectively. Tumor tissues were taken immediately after the scanning and fixed with 10% formalin and paraffin-embedded sections. The MRI signal strength of the tumors and adjacent muscles were compared with changes detected under a microscope using HE and Prussian blue staining. RESULTS: SK-Br-3 tumors were introduced to the BALB/c mice successfully. The strongest signal intensity was detected by the MRI 360 min after injection with the antisense probe. The pathological examination revealed structural disorders of the tumor issues, with a large number of special-shaped cells arranged in a cancer nest shape. Punctuate blue iron particles were observed in all of the tumor issues, with the greatest density occurring at 360 min after the injection with the antisense probe. CONCLUSION: The MR4 optimal time for MRI scanning of tumors in BALB/c mice using c-erbB2 antisense probe labeled with superparamagnetic iron oxide nanoparticles should be set at 360 min after injection.


Assuntos
Elementos Antissenso (Genética) , Dextranos , Genes erbB-2 , Nanopartículas de Magnetita , Neoplasias Experimentais/diagnóstico , Animais , Feminino , Aumento da Imagem , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Imagem Molecular , Nanopartículas , Fatores de Tempo
11.
Huan Jing Ke Xue ; 44(4): 1985-1997, 2023 Apr 08.
Artigo em Zh | MEDLINE | ID: mdl-37040949

RESUMO

In order to evaluate the effect and mechanism of energy saving and carbon reduction of the Air Pollution Prevention and Control Action Plan (the Policy), on the basis of measuring the energy consumption and CO2 emissions of GDP per unit area in 281 prefecture-level cities and above from 2003 to 2017, the influence, intermediary effect of innovation, and urban heterogeneity of the Policy on energy saving and carbon reduction were explored by using a difference-in-difference model. The results showed that:① the Policy promoted a significant reduction of 17.60% in the energy consumption intensity and 19.99% in the carbon emission intensity in the whole sample city. Based on a series of robustness tests, such as the parallel trend test, overcomed endogenous and placebo, dynamic time window and counterfactual, difference-in-difference-in-differences, and PSM-DID estimation, the above conclusions were still valid. ② Mechanism analysis showed that the Policy achieved energy saving and carbon reduction through the direct innovation intermediary effect of green invention patents as the carrier, and the indirect innovation mediation effect of the industrial structure upgrading effect caused by innovation achieved an energy-saving effect. ③ Heterogeneity analysis showed that the energy saving and carbon reduction rate of the Policy for coal-consuming provinces was 0.86% and 3.25% higher than that of non-coal-consuming provinces. The carbon reduction in the old industrial base city was 36.43% higher than that in the non-old industrial base, but the energy saving effect was 8.93% lower than that of the non-old industrial base. The range of energy saving and carbon reduction in non-resource-based cities was 31.30% and 74.95% higher than that in resource-based cities, respectively. ④ The results showed that it was necessary to strengthen the innovation investment and industrial structure upgrading in key areas such as big coal-consumption provinces, old industrial base cities, and resource-based cities, so as to give full play to the energy saving and carbon reduction effect of the Policy.

12.
Front Cell Infect Microbiol ; 13: 1107170, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36816587

RESUMO

Objectives: Metagenomic next-generation sequencing (mNGS) technology is helpful for the early diagnosis of infective endocarditis, especially culture-negative infective endocarditis, which may guide clinical treatment. The purpose of this study was to compare the presence of culture-negative infective endocarditis pathogens versus culture-positive ones, and whether mNGS test results could influence treatment regimens for patients with routine culture-negative infective endocarditis. Methods: The present study enrolled patients diagnosed with infective endocarditis and tested for mNGS in the First Affiliated Hospital of Zhengzhou University from February 2019 to February 2022 continuously. According to the culture results, patients were divided into culture-negative group (Group CN, n=18) and culture-positive group (Group CP, n=32). The baseline characteristics, clinical data, pathogens, 30 day mortality and treatment regimen of 50 patients with infective endocarditis were recorded and analyzed. Results: Except for higher levels of PCT in the Group CN [0.33 (0.16-2.74) ng/ml vs. 0.23 (0.12-0.49) ng/ml, P=0.042], there were no significant differences in the basic clinical data and laboratory examinations between the two groups (all P>0.05). The aortic valve and mitral valve were the most involved valves in patients with infective endocarditis (aortic valve involved: Group CN 10, Group CP 16; mitral valve involved: Group CN 8, Group CP 21; P>0.05) while 9 patients had multiple valves involved (Group CN 2, Group CP 7; P>0.05). The detection rate of non-streptococci infections in the Group CN was significantly higher than that in the Group CP (9/18 vs. 3/32, P=0.004). There was no significant difference in patients with heart failure hospitalization and all-cause death at 30 days after discharge (3 in Group CN vs. 4 in Group CP, P>0.05). It is worth noting that 10 patients with culture-negative infective endocarditis had their antibiotic regimen optimized after the blood mNGS. Conclusions: Culture-negative infective endocarditis should be tested for mNGS for early diagnosis and to guide clinical antibiotic regimen.


Assuntos
Endocardite Bacteriana , Endocardite , Humanos , Endocardite Bacteriana/complicações , Endocardite/diagnóstico , Valva Mitral , Sequenciamento de Nucleotídeos em Larga Escala , Metagenômica , Antibacterianos
13.
Front Endocrinol (Lausanne) ; 13: 801930, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35250862

RESUMO

AIM: Bone collagen matrix makes a crucial contribution to the mechanical properties of bone by imparting tensile strength and elasticity. The collagen content of bone is accessible via quantification of collagen bound water (CBW) indirectly. We prospectively study the performance of the CBW proton density (CBWPD) measured by a 3D short repetition time adiabatic inversion recovery prepared ultrashort echo time (STAIR-UTE) magnetic resonance imaging (MRI) sequence in the diagnosis of osteoporosis in human lumbar spine. METHODS: A total of 189 participants with a mean age of 56 (ranged from 50 to 86) years old were underwent MRI, quantitative computed tomography (QCT), and dual-energy X-ray absorptiometry (DXA) in lumbar spine. Major fracture risk was also evaluated for all participants using Fracture Risk Assessment Tool (FRAX). Lumbar CBWPD, bone marrow fat fraction (BMFF), bone mineral density (BMD) and T score values were calculated in three vertebrae (L2-L4) for each subject. Both the CBWPD and BMFF were correlated with BMD, T score, and FRAX score for comparison. The abilities of the CBWPD and BMFF to discriminate between three different cohorts, which included normal subjects, patients with osteopenia, and patients with osteoporosis, were also evaluated and compared using receiver operator characteristic (ROC) analysis. RESULTS: The CBWPD showed strong correlation with standard BMD (R2 = 0.75, P < 0.001) and T score (R2 = 0.59, P < 0.001), as well as a moderate correlation with FRAX score (R2 = 0.48, P < 0.001). High area under the curve (AUC) values (≥ 0.84 using QCT as reference; ≥ 0.76 using DXA as reference) obtained from ROC analysis demonstrated that the CBWPD was capable of well differentiating between the three different subject cohorts. Moreover, the CBWPD had better correlations with BMD, T score, and FRAX score than BMFF, and also performed better in cohort discrimination. CONCLUSION: The STAIR-UTE-measured CBWPD is a promising biomarker in the assessment of bone quality and fracture risk.


Assuntos
Fraturas Ósseas , Osteoporose , Idoso , Idoso de 80 Anos ou mais , Osso Esponjoso/diagnóstico por imagem , Colágeno , Humanos , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Osteoporose/diagnóstico por imagem , Água
14.
Orthop Surg ; 14(9): 2256-2264, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35979964

RESUMO

OBJECTIVE: 3D reconstruction of lumbar intervertebral foramen (LIVF) has been beneficial in evaluating surgical trajectory. Still, the current methods of reconstructing the 3D LIVF model are mainly based on manual segmentation, which is laborious and time-consuming. This study aims to explore the feasibility of automatically segmenting lumbar spinal structures and increasing the speed and accuracy of 3D lumbar intervertebral foramen (LIVF) reconstruction on magnetic resonance image (MRI) at the L4-5 level. METHODS: A total of 100 participants (mean age: 42.2 ± 14.0 years; 52 males and 48 females; mean body mass index, 22.7 ± 3.2 kg/m2 ), were enrolled in this prospective study between March and July 2020. All participants were scanned on L4-5 level with a 3T MR unit using 3D T2-weighted sampling perfection with application-optimized contrast with various flip-angle evolutions (SPACE) sequences. The lumbar spine's vertebra bone structures (VBS) and intervertebral discs (IVD) were manually segmented by skilled surgeons according to their anatomical outlines from MRI. Then all manual segmentation were saved and used for training. An automated segmentation method based on a 3D U-shaped architecture network (3D-UNet) was introduced for the automated segmentation of lumbar spinal structures. A number of quantitative metrics, including dice similarity coefficient (DSC), precision, and recall, were used to evaluate the performance of the automated segmentation method on MRI. Wilcoxon signed-rank test was applied to compare morphometric parameters, including foraminal area, height and width of 3D LIVF models between automatic and manual segmentation. The intra-class correlation coefficient was used to assess the test-retest reliability and inter-observer reliability of multiple measurements for these morphometric parameters of 3D LIVF models. RESULTS: The automatic segmentation performance of all spinal structures (VBS and IVD) was found to be 0.918 (healthy levels: 0.922; unhealthy levels: 0.916) for the mean DSC, 0.922 (healthy levels: 0.927; unhealthy levels: 0.920) for the mean precision, and 0.917 (healthy levels: 0.918; unhealthy levels: 0.917) for the mean recall in the test dataset. It took approximately 2.5 s to achieve each automated segmentation, far less than the 240 min for manual segmentation. Furthermore, no significant differences were observed in the foraminal area, height and width of the 3D LIVF models between manual and automatic segmentation images (P > 0.05). CONCLUSION: A method of automated MRI segmentation based on deep learning algorithms was capable of rapidly generating accurate segmentation of spinal structures and can be used to construct 3D LIVF models from MRI at the L4-5 level.


Assuntos
Aprendizado Profundo , Imageamento Tridimensional , Adulto , Feminino , Humanos , Imageamento Tridimensional/métodos , Vértebras Lombares/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes
15.
Front Endocrinol (Lausanne) ; 13: 890371, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35733770

RESUMO

Aim: Accurate severity grading of lumbar spine disease by magnetic resonance images (MRIs) plays an important role in selecting appropriate treatment for the disease. However, interpreting these complex MRIs is a repetitive and time-consuming workload for clinicians, especially radiologists. Here, we aim to develop a multi-task classification model based on artificial intelligence for automated grading of lumbar disc herniation (LDH), lumbar central canal stenosis (LCCS) and lumbar nerve roots compression (LNRC) at lumbar axial MRIs. Methods: Total 15254 lumbar axial T2W MRIs as the internal dataset obtained from the Fifth Affiliated Hospital of Sun Yat-sen University from January 2015 to May 2019 and 1273 axial T2W MRIs as the external test dataset obtained from the Third Affiliated Hospital of Southern Medical University from June 2016 to December 2017 were analyzed in this retrospective study. Two clinicians annotated and graded all MRIs using the three international classification systems. In agreement, these results served as the reference standard; In disagreement, outcomes were adjudicated by an expert surgeon to establish the reference standard. The internal dataset was randomly split into an internal training set (70%), validation set (15%) and test set (15%). The multi-task classification model based on ResNet-50 consists of a backbone network for feature extraction and three fully-connected (FC) networks for classification and performs the classification tasks of LDH, LCCS, and LNRC at lumbar MRIs. Precision, accuracy, sensitivity, specificity, F1 scores, confusion matrices, receiver-operating characteristics and interrater agreement (Gwet k) were utilized to assess the model's performance on the internal test dataset and external test datasets. Results: A total of 1115 patients, including 1015 patients from the internal dataset and 100 patients from the external test dataset [mean age, 49 years ± 15 (standard deviation); 543 women], were evaluated in this study. The overall accuracies of grading for LDH, LCCS and LNRC were 84.17% (74.16%), 86.99% (79.65%) and 81.21% (74.16%) respectively on the internal (external) test dataset. Internal and external testing of three spinal diseases showed substantial to the almost perfect agreement (k, 0.67 - 0.85) for the multi-task classification model. Conclusion: The multi-task classification model has achieved promising performance in the automated grading of LDH, LCCS and LNRC at lumbar axial T2W MRIs.


Assuntos
Deslocamento do Disco Intervertebral , Inteligência Artificial , Constrição Patológica/patologia , Feminino , Humanos , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Deslocamento do Disco Intervertebral/patologia , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
Front Cardiovasc Med ; 9: 995275, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36407434

RESUMO

Background: Ventricular septal rupture (VSR) is a type of cardiac rupture, usually complicated by acute myocardial infarction (AMI), with a high mortality rate and often poor prognosis. The aim of our study was to investigate the factors influencing the long-term prognosis of patients with VSR from different aspects, comparing the evaluation performance of the Gensini score, Sequential Organ Failure Assessment (SOFA) score and European Heart Surgery Risk Assessment System II (EuroSCORE II) score systems. Methods: This study retrospectively enrolled 188 patients with VSR between Dec 9, 2011 and Nov 21, 2021at the First Affiliated Hospital of Zhengzhou University. All patients were followed up until Jan 27, 2022 for clinical data, angiographic characteristics, echocardiogram outcomes, intraoperative, postoperative characteristics and major adverse cardiac events (MACEs) (30-day mortality, cardiac readmission). Cox proportional hazard regression analysis was used to explore the predictors of long-term mortality. Results: The median age of 188 VSR patients was 66.2 ± 9.1 years and 97 (51.6%) were males, and there were 103 (54.8%) patients in the medication group, 34 (18.1%) patients in the percutaneous transcatheter closure (TCC) group, and 51 (27.1%) patients in the surgical repair group. The average follow-up time was 857.4 days. The long-term mortality of the medically managed group, the percutaneous TCC group, and the surgical repair group was 94.2, 32.4, and 35.3%, respectively. Whether combined with cardiogenic shock (OR 0.023, 95% CI 0.001-0.054, P = 0.019), NT-pro BNP level (OR 0.027, 95% CI 0.002-0.34, P = 0.005), EuroSCORE II (OR 0.530, 95% CI 0.305-0.918, P = 0.024) and therapy group (OR 3.518, 95% CI 1.079-11.463, P = 0.037) were independently associated with long-term mortality in patients with VSR, and this seems to be independent of the therapy group. The mortality rate of surgical repair after 2 weeks of VSR was much lower than within 2 weeks (P = 0.025). The cut-off point of EuroSCORE II was determined to be 14, and there were statistically significant differences between the EuroSCORE II < 14 group and EuroSCORE II≥14 group (HR = 0.2596, 95%CI: 0.1800-0.3744, Logrank P < 0.001). Conclusion: Patients with AMI combined with VSR have a poor prognosis if not treated surgically, surgical repair after 2 weeks of VSR is a better time. In addition, EuroSCORE II can be used as a scoring system to assess the prognosis of patients with VSR.

17.
Tohoku J Exp Med ; 222(1): 15-21, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20808059

RESUMO

Colorectal cancer (CRC) is the third leading cause of cancer-related death in the world. Human colorectal carcinogenesis is a complex, multistep and multigenetic process. Cyclooxygenase-2 (COX2), a key enzyme in arachidonic acid metabolism, is overexpressed in several epithelial malignancies including colorectal cancer. COX2 expression can be induced by pro-inflammatory and mitogenic stimuli. The -765G/C polymorphism of the COX2 gene promoter has been reported to affect CRC susceptibility, but recent studies have demonstrated conflicting results. To shed light on these inconclusive findings, we performed a meta-analysis for assessing the involvement of COX2 -765G/C polymorphisms at the onset of colorectal carcinoma. Literature-based searching was guided to gather data and either fixed-effect or random-effect model was used to pool the odds ratio (OR) according to the test of heterogeneity. The 10 eligible case-control studies included 3,322 colorectal cancer cases and 5,166 controls. Overall, no evidence has indicated that individuals carrying GC+CC genotypes had significantly increased colorectal cancer risk compared with GG genotype [OR = 1.06, 95% confidence interval (95% CI) = 0.94-1.20]. However, stratified analysis with ethnicity indicated that individuals carrying GC+CC genotypes had an increased risk of colorectal cancer (OR = 1.40, 95% CI = 1.11-1.76) among Asian population. In conclusion, although not all bias could be eliminated, the -765C allele of the COX2 gene may be a potential risk factor for colorectal cancer in Asians.


Assuntos
Neoplasias Colorretais/genética , Ciclo-Oxigenase 2/genética , Polimorfismo Genético , Alelos , Predisposição Genética para Doença , Humanos , Fatores de Risco
18.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 41(1): 91-4, 2010 Jan.
Artigo em Zh | MEDLINE | ID: mdl-20369478

RESUMO

OBJECTIVE: To study the expression of paxillin in the two subgroups of human breast cancer cells with high and low metastatic potentialities and the effect of paxillin on tumor metastasis and adhesion. METHODS: Human breast cancer MDA-MB-435s cells were cultured in Transwell chamber with artificial matrigel, two subgroups of MDA-MB-435s cells with different metastatic potentiality were obtained by the ability of cells penetrating artificial matrigel. The expressions of paxillin mRNA and protein were examined by Immune histochemistry, Western blot and RT-PCR. The adhesion rates of the cells were examined by MTT. RESULTS: It was revealed by Immune histochemistry, Western blot, and RT-PCR that the expressions of paxillin at mRNA and protein levels were significantly higher in the cells with high metastatic potentiality. The difference was significant (t = 25.02,10.10, 17.18, P < 0.01). The adhesion rate was higher in the cells with high metastatic potentiality, and the difference was significant (F = 41.87, P < 0.01). CONCLUSION: The expression of paxillin may play an important role in human breast cancer metastasis and adhesion.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Metástase Neoplásica , Paxilina/metabolismo , Adesão Celular , Linhagem Celular Tumoral , Feminino , Humanos , Paxilina/genética
19.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 30(5): 554-8, 2008 Oct.
Artigo em Zh | MEDLINE | ID: mdl-19024385

RESUMO

OBJECTIVE: To prepare the superparamagnetic iron oxide (SPIO)-labeled antisense oligodeoxynucleotide (ASODN) probe and evaluate the application of this probe in cellular magnetic resonance imaging (MRI). METHODS: We prepared the SPIO-labeled ASODN probe using chemical cross linking method to conjugate SPIO to ASODN, detected its configuration by atomic force microscopy, determined the conjugating rate and biology activation by high performance liquid chromatography, and detected the stability by polyacrylamide gel electrophoresis. After that, we transfected the SK-Br3 oncocytes which had over-expression of the c-erbB2 oncogene by this probes, observed the intracellular iron distribution by optical microscope, measured iron content by atomic absorption spectroscopy, and observed the signal change by MRI. RESULTS: Atomic force microscope showed that the SPIO-labeled ASODN probe was mostly spherical and well-distributed, with a diameter of 25-40 nm and a conjugating rate of 100%. This probe had inhered biological activity and stability. In addition, light microscopy revealed an intracellular uptake of iron oxides in the transfected SK-Br3 oncocyte, and the iron content of the group of transfected SK-Br3 oncocytes was significantly higher than those of other contrast groups (all P < 0.01). MRI showed that transfected SK-Br3 oncocyte had the lowest signal among all other cells (all P < 0.05). CONCLUSIONS: We prepared the SPIO-labeled ASODN probe successfully. It can effectively transfect SK-Br3 oncocyte and enter SK-Br3 oncocyte, and thus reduce the signal intension in MRI.


Assuntos
DNA Antissenso/química , Compostos Férricos/química , Técnicas de Sonda Molecular , Oligodesoxirribonucleotídeos/química , Linhagem Celular Tumoral , DNA Antissenso/genética , Humanos , Imageamento por Ressonância Magnética , Magnetismo , Oligodesoxirribonucleotídeos/genética , Células Oxífilas/química , Receptor ErbB-2/análise , Receptor ErbB-2/genética
20.
Chin Med J (Engl) ; 131(9): 1092-1098, 2018 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-29451138

RESUMO

OBJECTIVE: Currently, magnetic resonance imaging (MRI) is the most commonly used imaging modality for observing the growth and development of mesenchymal stem cells (MSCs) after in vivo transplantation to treat osteoarthritis (OA). However, it is a challenge to accurately monitor the treatment effects of MSCs in the zone of calcified cartilage (ZCC) with OA. This is especially true in the physiological and biochemical views that are not accurately detected by MRI contrast agents. In contrast, ultrashort time echo (UTE) MRI has been shown to be sensitive to the presence of the ZCC, creating the potential for more effectively observing the repair of the ZCC in OA by MSCs. A special focus is given to the outlook of the use of UTE MRI to detect repair of the ZCC with OA through MSCs. The limitations of the current techniques for clinical applications and future directions are also discussed. DATA SOURCES: Using the combined keywords: "osteoarthritis", "mesenchymal stem cells", "calcified cartilage", and "magnetic resonance imaging", the PubMed/MEDLINE literature search was conducted up to June 1, 2017. STUDY SELECTION: A total of 132 published articles were initially identified citations. Of the 132 articles, 48 articles were selected after further detailed review. This study referred to all the important English literature in full. RESULTS: In contrast, UTE MRI has been shown to be sensitive to the presence of the ZCC, creating the potential for more effectively observing the repair of the ZCC in OA by MSCs. CONCLUSIONS: The current studies showed that the ZCC could be described in terms of its histomorphology and biochemistry by UTE MRI. We prospected that UTE MRI has been shown the potential for more effectively observing the repair of the ZCC in OA by MSCs in vivo.


Assuntos
Imageamento por Ressonância Magnética/métodos , Osteoartrite/diagnóstico por imagem , Osteoartrite/terapia , Cartilagem Articular/diagnóstico por imagem , Humanos , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA