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1.
ACS Omega ; 9(16): 18375-18384, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38680328

RESUMO

Oxaliplatin (OXA) is recognized as a first-line drug for gastric cancer. However, low accumulation of the OXA in the target site and the development of drug resistance directly led to treatment failure. In the present study, an ultrasonic extraction method for Atractylodes chinensis (DC.) Koidz. polysaccharides (AKUs) and the combination treatment with OXA in vitro were studied. Results showed that when the pH level was 11, the ultrasound power at 450 W, the solid-liquid ratio was 1:20, and the ultrasound treatment for 30 min, the yield of AKUs was significantly increased to 13.20 ± 0.35%. The molecular weights of the AKUs ranged from 7.21 to 185.94 kDa, and its monosaccharides were mainly composed of arabinose (Ara), galactose (Gal), and glucose (Glu) with a ratio of 58.36, 16.90, and 15.49%, respectively. Cell experiments showed that, compared to OXA alone (2 µg/mL, inhibition rate of 18%), the treatment of OXA with AKUs had a significant synergistic inhibitory effect on MKN45 proliferation, which increased to 33, 41, and 45% with increasing AKUs concentrations (5-50 µg/mL), respectively, representing a 2.5-fold inhibition. Inductively coupled plasma-mass spectrometry (ICP-MS) determination confirmed that AKUs significantly increased the intracellular uptake of OXA by 29%, compared to that of OXA alone. We first demonstrated that the combined synergistic inhibitory effect of AKUs and OXA on gastric cancer cells was mediated by reducing the expression of efflux proteins (MRP1 and MRP2) and increasing the expression of ingested protein (OCT2). As a result of the above, AKUs deserved to be an effective adjuvant combined with chemotherapeutics in a clinical setting.

2.
Materials (Basel) ; 15(24)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36556592

RESUMO

This paper investigated the effect of silicon phase morphology and size on microstructure, mechanical properties, and corrosion resistance of the AlSi10Mg alloys fabricated by selective laser melting (SLM). Using different heat treatment conditions for SLM-fabricated alloys, the microstructure characteristics and mechanical properties are analyzed. The corrosion behavior analysis is also performed using potentiodynamic polarization, electrochemical and immersion tests. Results show that the AlSi10Mg alloy directly fabricated by SLM has a continuous eutectic silicon network, which has a small driving force for corrosion and facilitates the deposition of corrosion products and generates a dense protective film. On the contrary, the formation of large isolated and uniformly distributed silicon particles produces a greater corrosion driving force after heat treatment, which makes most of the corrosion products transfer to the solution. The corrosion resistance of AlSi10Mg alloy directly fabricated by SLM is better than that of the alloys with heat treatment. Moreover, the heat treatment reduces the hardness of AlSi10Mg alloys due to the decrease in the solid solution strengthening effect.

3.
Front Microbiol ; 13: 1021080, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36262325

RESUMO

Nitrogen (N) cycling microorganisms mediate soil nitrogen transformation processes, thereby affecting agricultural production and environment quality. However, it is not fully understood how active N-cycling microbial community in soil respond to long-term fertilization, as well as which microorganisms regulate soil nitrogen cycling in agricultural ecosystem. Here, we collected the soils from different depths and seasons at a 29-year fertilization experimental field (organic/chemical fertilizer), and investigated the transcriptions of N-cycling functional genes and their contribution to potential nitrification and denitrification. We found that long-term fertilization exerted significant impacts on the transcript abundances of nitrifiers (AOA amoA, AOB amoA and hao) and denitrifiers (narG and nosZ), which was also notably influenced by season variation. The transcriptions of AOA amoA, hao, and narG genes were lowest in autumn, and AOB amoA and nosZ transcript abundances were highest in autumn. Compared to no fertilization, soil potential nitrification rate (PNR) was reduced in fertilization treatments, while soil potential denitrification rate (PDR) was significantly enhanced in organic combined chemical fertilizer treatment. Both PNR and PDR were highest in 0-20 cm among the tested soil depths. Path model indicated active nitrifiers and denitrifiers had significant impact on soil PNR and PDR, respectively. The transcriptions of AOA amoA and nxr genes were significantly correlated with soil PNR (Pearson correlation, r > 0.174, p < 0.05). Significant correlation of napA and nosZ transcriptions with soil PDR (Pearson correlation, r > 0.234, p < 0.05) was also revealed. Random forest analysis showed that SOC content and soil pH were the important factors explaining the total variance of active nitrifers and denitrifiers, respectively. Taken together, long-term fertilization regimes reduced soil PNR and enhanced PDR, which could be attributed to the different responses of active N-cycling microorganisms to soil environment variations. This work provides new insight into the nitrogen cycle, particularly microbial indicators in nitrification and denitrification of long-term fertilized agricultural ecosystems.

4.
Quant Imaging Med Surg ; 12(2): 1223-1234, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35111618

RESUMO

BACKGROUND: Ultrasound is commonly used in breast cancer screening but lacks quantification ability and diagnostic power due to its low specificity, which can lead to overdiagnosis and unnecessary biopsies. This study evaluated the diagnostic efficacy and clinical utility of adding shear-wave elastography (SWE) to the screening of the Breast Imaging Reporting and Data System (BI-RADS) category 4 breast cancer. METHODS: A machine learning-based diagnostic model was constructed using data retrospectively collected from 3 independent cohorts with features selected using lasso regression and support vector machine-recursive feature elimination algorithms. Propensity score matching (PSM) was used to preclude confounding baseline characteristics between malignant and benign lesions. A decision curve analysis (DCA) was used to evaluate the clinical benefit of the diagnostic model in identifying high-risk tumor patients for intervention while simultaneously avoiding overtreatment of low-risk patients with integrative evaluation using a net benefit value and treatment reduction rate. RESULTS: In our training center, a total of 122 patients were enrolled, and 577 breast tumors were collected. The comparison between malignant and benign lesions revealed significant differences in patient age, tumor size, resistance index (RI), and elasticity values. The maximum elasticity value (Emax) was identified as an independent diagnostic feature and was included in the diagnostic model. The combination of Emax with BI-RADS category 4 demonstrated a significantly better diagnostic efficacy than the BI-RADS category alone [BI-RADS+Emax: AUC =0.908, 95% confidence interval (CI): 0.842-0.974; BI-RADS: AUC =0.862, 95% CI: 0.784-0.94; P=0.024] and significantly increased the clinical benefit for patients and policy makers by effectively reducing overdiagnosis and biopsy rates. In the BI-RADS category 4A subgroup, adding Emax to breast cancer screening benefited patients and showed a greater absolute benefit than did the BI-RADS category alone when used for patients with a higher probability of cancer (>0.403), demonstrating a 50% overtreatment reduction. CONCLUSIONS: Adding Emax to BI-RADS category 4 breast cancer screening using SWE significantly reduced overdiagnosis and biopsy rates compared with the BI-RADS category alone, especially for BI-RADS 4A patients.

5.
Brain Imaging Behav ; 15(5): 2492-2501, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33570727

RESUMO

Using diffusion kurtosis imaging (DKI) to evaluate the brain changes, the therapeutic effect and mechanism of tetramethylpyrazine in rats with dementia induced by lipopolysaccharide. Thirty-six male Sprague-Dawley rats were randomly divided into control group and five groups pretreated with sham operation, lipopolysaccharide(150ug) and three doses of tetramethylpyrazine(5, 10, and 20 mg/mL respectively). The Morris water maze test was used to evaluate cognitive ability. DKI and histology were performed. Low-dose of tetramethylpyrazine pretreated rats showed lower escape latency(6th day: 15.92seconds(s) vs. 5.11 s, P = 0.001), spent more time in the target quadrant(15.67 s vs. 29.83 s, P = 0.009) and crossed the platform area more frequently(3.50 vs. 9.17, P = 0.001) than rats in the LPS-treated group. Compared to sham group, the fractional anisotropy (FA), axial diffusion (Da), mean kurtosis (MK), and axial kurtosis (Ka) values in the cortex of lipopolysaccharide group were lower (P = 0.021,0.003,0.003,0.001,respectively).The MK, Ka, Kr, and FA values in the hippocampus of the lipopolysaccharide group were higher (P = 0.01, 0.026,0.007,0.003,respectively),while MD and Da values were lower (P = 0.045,0.044, respectively). Tetramethylpyrazine-pretreated rats showed higher values of FA, MD, Da, MK, and Ka in the cortex, lower MK, Ka, Kr, and FA values and higher MD,Da values in the hippocampus than the lipopolysaccharide group. Histologically, prominent inflammatory cells infiltration in the brain parenchyma of lipopolysaccharide group were observed, while groups pretreated using tetramethylpyrazine were alleviated. Tetramethylpyrazine can improve cognitive dysfunction induced by lipopolysaccharide. DKI can sensitively detect microstructure integrity of brain parenchyma in a non-invasive manner.


Assuntos
Disfunção Cognitiva , Lipopolissacarídeos , Animais , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/tratamento farmacológico , Imagem de Difusão por Ressonância Magnética , Imageamento por Ressonância Magnética , Masculino , Pirazinas , Ratos , Ratos Sprague-Dawley
6.
Mater Sci Eng C Mater Biol Appl ; 119: 111521, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33321608

RESUMO

Magnesium alloys can work as biomedical materials due to their Young's modules similar to that of bone. Nevertheless, in a human plasma, one of the major drawbacks of these materials is the low corrosion resistance. Here, AZ80 corrosion in the solutions containing chloride, bicarbonate, sulphate and hydrogen phosphate ions were investigated by a short-term immersion test and electrochemical techniques. The results showed that bicarbonate and hydrogen phosphate could retard corrosion rate, while chloride and sulphate accelerated corrosion rate. During the early immersion stage, the corrosion rate increased with the presence of bicarbonate. It was caused by the reaction of bicarbonate and hydroxide promoting the dissolution of magnesium and accelerating corrosion. In the later stage, the reduced corrosion rate was due to the formation of various protective films. The sample formed a new sparse porous MgSO4·5H2O compounds in the sulphate ion solution, which could not effectively prevent chloride ions from entering the matrix and thus accelerated the dissolution of magnesium. With the presence of hydrogen phosphate, magnesium phosphate with a much lower solubility was formed, preferentially precipitated on the surface and was not influenced by the chloride ions. The corrosion mechanisms of magnesium alloys in above ions were proposed.


Assuntos
Ligas , Magnésio , Materiais Biocompatíveis , Corrosão , Humanos , Íons , Teste de Materiais , Propriedades de Superfície
7.
Materials (Basel) ; 13(18)2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32911692

RESUMO

AlSi10Mg alloy branches were fabricated by selective laser melting (SLM), and the branches were employed to evaluate their effect on the mechanical properties. When the porous branches were compressed along its building direction, the tree column structures-type AlSi10Mg alloy branches collapsed twice, which had typical elastic, shear, collapse, and densification stages. The compressive stress concentration at the interface between the support and the porous body caused the fracture of the tree column structures-type AlSi10Mg alloy branches. The fracture surface indicated that the prepared tree-type branches were distributed with different shapes of dimples, and the Si content inside the dimples was higher than that of the edge. The morphology of the Al-Si eutectic structure formed by SLM and the stress concentration at the Al/Al-Si-eutectic interface affected the fracture morphology and Si content distribution.

8.
Neurosci Lett ; 723: 134865, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32109554

RESUMO

Irritable bowel syndrome (IBS) is a brain-gut disorder that is often accompanied by psychiatric comorbidities, particularly depression. However, the neuroanatomical substrates of IBS with depressive symptoms (DEP-IBS) and how depressive symptoms and brain morphology modulate IBS symptoms remain unknown. In this study, structural MRI data were processed using a voxel-based morphometry technique and one-way analysis of covariance (ANCOVA) and post-hoc t-tests were performed to compare gray matter volume (GMV) among 28 patients with DEP-IBS, 21 patients with IBS who lacked depressive symptoms (nDEP-IBS), and 36 healthy controls (HC). Correlation and mediation analyses were performed to evaluate the relationship between differing GMV in DEP-IBS and clinical variables. We found that GMV in the bilateral prefrontal, insular, and dorsal striatal areas, as well as the left temporal pole, were significantly lower in the DEP-IBS group than in the HC group. Moreover, compared with the nDEP-IBS group, the DEP-IBS group exhibited decreased GMV in the bilateral medial, dorsolateral prefrontal, and orbitofrontal cortices, bilateral dorsal striatum, and left insular cortices. Correlation analysis revealed that GMV in these atrophic brain areas of the DEP-IBS group was negatively correlated with depression, gastrointestinal symptoms, and disease duration. Our results further revealed that depressive symptoms served as a mediator between gastrointestinal symptoms and GMV in the left insula, right medial prefrontal cortex, and right middle frontal gyrus, while gastrointestinal symptoms served as a mediator between depression and GMV in these regions. Our results suggest convergent syndromic atrophy in the pain and emotional systems of patients with DEP-IBS.


Assuntos
Depressão/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Síndrome do Intestino Irritável/diagnóstico por imagem , Sistema Límbico/diagnóstico por imagem , Dor/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Adulto , Atrofia , Depressão/epidemiologia , Depressão/psicologia , Feminino , Humanos , Síndrome do Intestino Irritável/epidemiologia , Síndrome do Intestino Irritável/psicologia , Masculino , Dor/epidemiologia , Dor/psicologia
9.
J Magn Reson Imaging ; 51(6): 1836-1843, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31785074

RESUMO

BACKGROUND: Central nervous system inflammation is associated with neurodegenerative diseases and is thought to play a part in the pathophysiological cascade leading to cognitive impairment. Madecassoside (MA) has shown potential for the treatment of neuroinflammation. Lipopolysaccharide (LPS) can be used to establish an animal model of cognitive dysfunction induced by neuroinflammation. Intravoxel incoherent motion (IVIM) may potentially provide diffusion and perfusion data. PURPOSE: To investigate the effect of MA on neurocognitive impairment induced by LPS in rats, and to explore the changes of brain microstructure and microcirculatory perfusion by IVIM imaging. STUDY TYPE: Prospective. POPULATION: Thirty-six male Sprague-Dawley rats were randomly divided into six groups (control group, sham operation group, LPS group, low-dose MA group, middle-dose MA group, and high-dose MA group) in a model of neurocognitive impairment induced by LPS (150 µg / 5 µL, 5 µL). FIELD STRENGTH/SEQUENCE: IVIM-DWI sequence at 3.0T MRI; the scan time was 2 minutes and 17 seconds. ASSESSMENT: The escape latency times of a Morris water maze test was used to evaluate the cognitive impairment rat model and the changes of learning ability of rats treated with different doses of MA (30 mg/kg, 60 mg/kg, 120 mg/kg). A GE postprocessing workstation (adw 4.5) was used to analyze the changes of each parameter (f value, D value, and D* value) in the IVIM data of each group. STATISTICAL TESTS: All the data were analyzed by one-way and two-way analysis of variance (ANOVA). RESULTS: The escape latency of the LPS group was significantly longer than the sham group (P = 0.05, 0.001, 0.006, and 0.042, respectively), and the high-dose group was significantly shorter than the LPS group on the sixth day (P = 0.034). Compared with the control group, the D values and f values of cerebral cortex and hippocampus were decreased significantly in the LPS group (P = 0.043 and 0.003; P = 0.029 and 0.016, respectively). With the increasing dose of MA, the D and f values of hippocampus and cortex increased, and there was a significant difference between the high-dose MA group and LPS group (D values: P = 0.038, 0.036; f values: P = 0.048, 0.039, respectively) DATA CONCLUSION: MA can improve the cognitive impairment induced by LPS by reducing neuroinflammation, and the changes of microcirculation and microperfusion in the brain tissue of these rats can be detected by IVIM imaging. LEVEL OF EVIDENCE: 1 Technical Efficacy Stage: 4 J. Magn. Reson. Imaging 2020;51:1836-1843.


Assuntos
Disfunção Cognitiva , Imagem de Difusão por Ressonância Magnética , Animais , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Lipopolissacarídeos , Masculino , Microcirculação , Movimento (Física) , Estudos Prospectivos , Ratos , Ratos Sprague-Dawley , Triterpenos
10.
Materials (Basel) ; 12(6)2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30901913

RESUMO

In order to improve the abrasion performance of 316Lss, make full use of its advantages and broaden its application fields, the tribological behavior of the TiC particles reinforced 316Lss composites-which were manufactured by selective laser melting (SLM)-were investigated. In this study, GCr15 bearing steel was selected as the friction material and experiments on the sliding friction and wear under different loads of 15 N, 25 N and 35 N at the sliding speeds of 60, 80 and 100 mm/min were carried out, respectively. The results show that the wear performance of the TiC/316Lss composite is higher than that of the matrix during the friction and wear experiments under all conditions and the wear rate of the TiC/316Lss composite decreases with increasing the friction rate. Similar to the wear mechanism under different loads, it changes from abrasive wear to delamination wear and severe oxidative wear. At the same time, the mechanical mixed layer formed at a high speed has a protective effect on the matrix. The reason for this phenomenon is that the mechanical properties of the TiC/316Lss composites are significantly improved due to the addition of TiC particles, the refinement of cells near the TiC particles and the formation of a large number of dislocations. In addition, due to the presence of the TiC particles, the hardness and strength of the TiC/316Lss composites are greatly improved, thus the processing hardening ability of sub-surface has been improved.

11.
J Magn Reson Imaging ; 49(4): 1105-1112, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30302864

RESUMO

BACKGROUND: Prediabetes is an intermediate state in which blood glucose is higher than normal but does not meet the diagnostic criteria for diabetes. Diffusion tensor imaging (DTI) is an MRI method that can sensitively detect microscopic lesions in the white matter of the brain, but most previous DTI studies only focused on patients with diabetes, and little is known about prediabetes. PURPOSE: To investigate the changes in the microstructure of brain white matter in prediabetes patients using DTI and trace-based spatial statistics (TBSS). STUDY TYPE: Prospective. POPULATION: Sixty subjects (30 patients with prediabetes and 30 healthy volunteers) were enrolled. FIELD STRENGTH/SEQUENCE: 3.0T/DTI-MRI sequence with single-shot echo-planar imaging sequence (SE-EPI). ASSESSMENT: DTI data were collected and analyzed using the TBSS method in the FMRIB software library. STATISTICAL TESTS: DTI using a two-sample t-test. Pearson correlation analysis was performed on DTI values and neuropsychology scale results (mini-mental state examination [MMSE], Montreal cognitive assessment [MoCA], self-rating anxiety scale [SAS], and self-rating depression scale [SDS]) RESULTS: Compared with the control group, the fractional anisotropy (FA) values in the right part of the corpus callosum body (bCC) (P = 0.035), the right superior longitudinal fasciculus (SLF.R) (P = 0.047), and the left superior longitudinal fasciculus (SLF.L) in the prediabetic group were reduced (P = 0.040). DATA CONCLUSION: DTI as a noninvasive technique can assess early changes in the white matter microarchitecture of patients with prediabetes. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1105-1112.


Assuntos
Imagem de Tensor de Difusão , Estado Pré-Diabético/diagnóstico por imagem , Substância Branca/diagnóstico por imagem , Adulto , Idoso , Glicemia/análise , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Prognóstico , Estudos Prospectivos , Software
12.
Nanomedicine ; 12(1): 235-44, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26393884

RESUMO

Microwave-induced thermoacoustic imaging (TAI) can map the microwave absorption distribution of targets, which depends on the electrical and magnetic properties. Although carbon nanotubes (CNTs) with good electrical properties have been used as TAI contrast agents, the negligible magnetic absorption hinders its application for sensitive detection. In order to exploit CNTs with electrical and magnetic absorption properties as agent of TAI, the ferromagnetic material-filled multi-walled CNTs (MMWCNTs) are investigated. In this study, the folic acid conjugated plain multiwalled CNTs (MWCNTs) and MMWCNTs were injected through the tail-vein of mice separately, and TAI and magnetic resonance imaging (MRI) were performed. The results show the MMWCNTs can clearly image the size and edge of the tumor with the TAI contrast enhancement of 67% and T2 signal intensity decrease of four fifths compared to MWCNTs. This study demonstrated the hybrid particles have the potential to be a high-sensitive contrast agent for accurate tumor detection. From the Clinical Editor: Novel imaging modalities are emerging. Microwave-induced thermoacoustic imaging (TAI) relies on the absorption distribution of microwave of targets. In this article the authors investigate the use of ferromagnetic material-filled multi-walled CNTs as contrast agents for both TAI and MRI in an in-vivo model for tumors. The positive findings would imply that the application of dual-modality probe could provide more accurate imaging for the clinical setting.


Assuntos
Ferro/química , Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Nanotubos de Carbono/química , Neoplasias Experimentais/patologia , Termografia/métodos , Animais , Meios de Contraste/síntese química , Técnicas de Imagem por Elasticidade/métodos , Feminino , Ácido Fólico/química , Ácido Fólico/farmacocinética , Nanopartículas de Magnetita/química , Camundongos , Camundongos Endogâmicos BALB C , Micro-Ondas , Nanotubos de Carbono/ultraestrutura , Neoplasias Experimentais/metabolismo , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Cogn Neurodyn ; 9(6): 573-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26557927

RESUMO

A piece-wise linear planar neuron model, namely, two-dimensional McKean model with periodic drive is investigated in this paper. Periodical bursting phenomenon can be observed in the numerical simulations. By assuming the formal solutions associated with different intervals of this non-autonomous system and introducing the generalized Jacobian matrix at the non-smooth boundaries, the bifurcation mechanism for the bursting solution induced by the slowly varying periodic drive is presented. It is shown that, the discontinuous Hopf bifurcation occurring at the non-smooth boundaries, i.e., the bifurcation taking place at the thresholds of the stimulation, leads the alternation between the rest state and spiking state. That is, different oscillation modes of this non-autonomous system convert periodically due to the non-smoothness of the vector field and the slow variation of the periodic drive as well.

14.
Biomed Res Int ; 2015: 917640, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26355740

RESUMO

A set of optical models associated with blood cells are introduced in this paper. All of these models are made up of different parts possessing symmetries. The wrapped phase images as well as the unwrapped ones from two orthogonal directions related to some of these models are obtained by simulation technique. Because the phase mutation occurs on the boundary between nucleus and cytoplasm as well as on the boundary between cytoplasm and environment medium, the equation of inflexion curve is introduced to describe the size, morphology, and substructure of the nuclear cell based on the analysis of the phase features of the model. Furthermore, a mononuclear cell model is discussed as an example to verify this method. The simulation result shows that characterization with inflexion curve based on orthogonal phase images could describe the substructure of the cells availably, which may provide a new way to identify the typical biological cells quickly without scanning.


Assuntos
Células Sanguíneas/citologia , Algoritmos , Núcleo Celular/fisiologia , Citoplasma/fisiologia , Humanos , Imageamento Tridimensional/métodos
15.
PLoS One ; 8(12): e79999, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24324588

RESUMO

BACKGROUND: To identify changes in brain activation patterns in bipolar disorder (BD) and unipolar depression (UD) patients. METHODOLOGY/PRINCIPAL FINDINGS: Resting-state fMRI scans of 16 healthy controls, 17 BD and 16 UD patients were obtained. T-test of normalized regional homogeneity (ReHo) was performed in a voxel-by-voxel manner. A combined threshold of á = 0.05, minimum cluster volume of V = 10503 mm(3) (389 voxels) were used to determine ReHo differences between groups. In UD group, fMRI revealed ReHo increases in the left middle occipital lobe, right inferior parietal lobule, right precuneus and left convolution; and ReHo decreases in the left parahippocampalgyrus, right precentralgyrus, left postcentralgyrus, left precentralgyrus and left cingulated. In BD group, ReHo increases in the right insular cortex, left middle frontal gyrus, left precuneus, left occipital lobe, left parietal, left superior frontal gyrus and left thalamus; and ReHo decreases in the right anterior lobe of cerebellum, pons, right precentralgyrus, left postcentralgyrus, left inferior frontal gyrus, and right cingulate. There were some overlaps in ReHo profiles between UD and BD groups, but a marked difference was seen in the thalamus of BD. CONCLUSIONS/SIGNIFICANCE: The resting-state fMRI and ReHo mapping are a promising tool to assist the detection of functional deficits and distinguish clinical and pathophysiological signs of BD and UD.


Assuntos
Transtorno Bipolar/patologia , Transtorno Depressivo/patologia , Tálamo/patologia , Adolescente , Adulto , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/fisiopatologia , Mapeamento Encefálico , Estudos de Casos e Controles , Cerebelo/patologia , Cerebelo/fisiopatologia , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/fisiopatologia , Feminino , Lobo Frontal/patologia , Lobo Frontal/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Lobo Occipital/patologia , Lobo Occipital/fisiopatologia , Lobo Parietal/patologia , Lobo Parietal/fisiopatologia , Tálamo/fisiopatologia
16.
J Magn Reson Imaging ; 34(6): 1325-32, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21953575

RESUMO

PURPOSE: To investigate how to label macrophages in atherosclerotic plaques with superparamagnetic iron oxide (SPIO) nanoparticles and trace SPIO with MR imaging. MATERIALS AND METHODS: Atherosclerotic lesions of a rabbit model were induced by a combination of high-fat and high-cholesterol diet and subsequent endothelial abrasion of the abdominal aorta. SPIO particles were pretreated with poly-L-lysine. SPIO nanoparticles and SPIO-labeled human endothelial cells (ECV-304) were IV injected into model animals, respectively. The MRI scans and histopathological examination were performed 12 h and 24 h after the injection. The imaging and histopathological data were analyzed. RESULTS: Prussian blue staining of the vessel specimens indicated that SPIO particles were not found in the atheroma but in the Kupffer's cells of the liver after SPIO injection. However, the accumulation of SPIO particles in the atheroma was confirmed in animals received SPIO-labeled endothelial cell transplantation. The best quality MR scan sequences of rabbit abdominal aorta were T(2) WI fat suppression, T(1) WI, and DIR series, on which of MR image had a higher quality. Signal loss of the original incrassate plaque in the vessel wall on T(2) WI was found in 6 of 10 animals received SPIO-labeled endothelial cell transplantation. CONCLUSION: SPIO-labeled endothelial cells were superior to SPIO for MR imaging of atherosclerotic plaques.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética/métodos , Nanopartículas de Magnetita , Placa Aterosclerótica/patologia , Animais , Aorta Abdominal/patologia , Células Endoteliais/química , Células Endoteliais/transplante , Humanos , Células de Kupffer/química , Macrófagos/química , Masculino , Coelhos , Transplante Heterólogo
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