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1.
Biomed Res Int ; 2020: 2851349, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31998784

RESUMO

Cisplatin is a widely used chemotherapeutic drug in the treatment of various solid tumors. However, the cisplatin-induced acute kidney injury remains a disturbing complication, which still lacks effective prevention. Cisplatin-induced oxidative damage and mitochondrial dysfunction are anticipated to be crucial in the occurrence of kidney injury. Astragalus polysaccharide (APS) has been reported to possess multiple biological activities including anti-inflammatory, antioxidant, and mitochondria protection. In this study, we investigated the potentially protective effect of APS against cisplatin-induced kidney injury both in vivo and in vitro. We found that APS pretreatment attenuated the cisplatin-induced renal dysfunction and histopathological damage in mice; in addition, it also protected the viability of HK-2 cells upon cisplatin exposure. APS attenuated the cisplatin-induced oxidative damage by reducing reactive oxygen species (ROS) generation and recovering the activities of total superoxide dismutase and glutathione peroxidase in mice kidney. In addition, electron microscope analysis indicated that cisplatin induced extensive mitochondrial vacuolization in mice kidney. However, APS administration reversed these mitochondrial morphology changes. In HK-2 cells, APS reduced the cisplatin-induced mitochondrial and intracellular ROS generation. Furthermore, APS protected the normal morphology of mitochondria, blocked the cisplatin-induced mitochondrial permeability transition pore opening, and reduced the cytochrome c leakage. Subsequently, APS reduced the cisplatin-induced apoptosis in mice renal and HK-2 cells. In conclusion, our data suggested that APS pretreatment might prevent cisplatin-induced kidney injury through attenuating oxidative damage, protecting mitochondria, and ameliorating mitochondrial-mediated apoptosis.

2.
J Control Release ; 320: 1-18, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31931050

RESUMO

The protein corona significantly changes the nanoparticle (NP) identity both physicochemically and biologically, and in situ regulation of specific plasma protein adsorption on NP surfaces has emerged as a promising strategy for disease-targeting therapy. In the past decade, great progress in protein corona regulation has been achieved via surface chemistry-based nanomedicine development. This review first outlines the latest advances in bio-nano interactions, with special attention to factors that influence the protein corona, including NP physicochemical properties, the biological environment and the duration time. Second, NP surface chemistry strategies designed to inhibit and regulate protein corona formation are highlighted, with special emphasis on albumin, transferrin, apolipoprotein (apo) E, vascular endothelial growth factor (VEGF) and retinol binding protein 4 (RBP4). Finally, the current techniques used to characterize the protein corona are briefly discussed.

3.
Int J Clin Oncol ; 25(2): 338-346, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31720994

RESUMO

OBJECTIVE: PBRM1, located on 3p21, functions as a tumor suppressor and somatic mutation of PBRM1 is frequent in clear cell renal cell carcinoma (ccRCC). This study aims to determine the influence of PBRM1 expression on the prognosis of patients with mRCC receiving tyrosine kinase inhibitor (TKI) treatment. METHODS: We identified 116 mRCC patients who were administered sunitinib or sorafenib as first-line therapy, between January 2006 and December 2016 at our institution. PBRM1 expression was assessed by immunohistochemistry. The Kaplan-Meier method was used to estimate the progression-free survival (PFS) and overall survival (OS), log-rank test was used to compare the survival outcomes between patients with low and high PBRM1 expression levels, and the Cox proportional hazard regression model was used to estimate the prognostic value. Prognostic accuracy was determined using Harrell concordance index, and nomograms were built to evaluate the prognosis of mRCC. RESULTS: Patients with low PBRM1 expression had significantly shorter median PFS (9 vs 26 months, P < 0.001) and OS (21 vs 44 months, P < 0.001) than those with high expression. Multivariate analysis showed that PBRM1 expression was an independent predictor of PFS (HR 1.975, P = 0.013) and OS (HR 2.282, P = 0.007). The model built by the addition of PBRM1 improved the C-index of PFS and OS to 0.72 and 0.82, respectively. CONCLUSIONS: The expression of PBRM1 could be a significant prognostic factor for mRCC patients treated with targeted therapy, and it increases the prognostic accuracy of the established prognostic model.

4.
J Neurosci Methods ; 332: 108531, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31830544

RESUMO

BACKGROUND: Functional magnetic resonance imaging (fMRI) has been implemented widely to study brain connectivity. In particular, time-varying connectivity analysis has emerged as an important measure to uncover essential knowledge within the network. On the other hand, independent component analysis (ICA) has served as a powerful tool to preprocess fMRI data before performing network analysis. Together, they may lead to novel findings. METHODS: We propose a new framework (GICA-TVGL) that combines group ICA (GICA) with time-varying graphical LASSO (TVGL) to improve the power of analyzing functional connectivity (FNC) changes, which is then applied for neuro-developmental study. To investigate the performance of our proposed approach, we apply it to capture dynamic FNC using both the Philadelphia Neurodevelopmental Cohort (PNC) and the Pediatric Imaging, Neurocognition, and Genetics (PING) datasets. RESULTS: Our results indicate that females and males in young adult group possess substantial difference related to visual network. In addition, some other consistent conclusions have been reached by using these two datasets. Furthermore, the GICA-TVGL model indicated that females had a higher probability to stay in a stable state. Males had a higher tendency to remain in a globally disconnected mode. COMPARISON WITH EXISTING METHOD: The performance of sliding window approach is largely affected by the window size selection. In addition, it also assumes temporal locality hypothesis. CONCLUSION: Our proposed framework provides a feasible method to investigate brain dynamics and has the potential to become a widely used tool in neuroimaging studies.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31283500

RESUMO

Adolescence is a transitional period between child-hood and adulthood with physical changes, as well as increasing emotional development. Studies have shown that emotional sensitivity is related to a second period of rapid brain growth. However, there is little focus on the trend of brain development during this period. In this paper, we aim to track functional brain connectivity development from late childhood to young adulthood. Mathematically, this problem can be modeled via the estimation of multiple Gaussian graphical models (GGMs). However, most existing methods either require the graph sequence to be fairly long or are only applicable to small graphs. In this work, we adapted a Bayesian approach incorporating joint estimation of multiple GGMs to overcome the short sequence difficulty, which is also computationally efficient. The data used are the fMRI images obtained from the publicly available Philadelphia Neurodevelopmental Cohort (PNC). They include 855 individuals aged 8-22 years who were divided into five different adolescent stages. We summarized the networks with global measurements and applied a hypothesis test across age groups to detect developmental patterns. Three patterns were detected and defined as consistent development, late puberty and temporal change. We also discovered several anatomical areas such as the middle frontal gyrus, putamen gyrus, right lingual gyrus and right cerebellum crus 2 that are highly involved in the brain functional development. Functional networks including the salience, subcortical and auditory networks are significantly developing during the adolescent period.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31329112

RESUMO

Estimating dynamic functional network connectivity (dFNC) of the brain from functional magnetic resonance imaging (fMRI) data can reveal both spatial and temporal organization and can be applied to track the developmental trajectory of brain maturity as well as to study mental illness. Resting state fMRI (rs-fMRI) is regarded as a promising task since it reflects the spontaneous brain activity without an external stimulus. The sliding window method has been successfully used to extract dFNC but typically assumes a fixed window size. The hidden Markov model (HMM) based method is an alternative approach for estimating time-varying connectivity. In this paper, we propose a sparse HMM based on Gaussian HMM and Gaussian graphical model (GGM). In this model, the time-varying neural processes are represented as discrete brain states which are described with functional connectivity networks. By enforcing the sparsity on the precision matrix, we can get interpretable connectivity between different functional regions. The optimization of our model can be realized with the expectation maximization (EM) and graphical least absolute shrinkage and selection operator (glasso) algorithms. The proposed model is validated on both simulated blood oxygenation-level dependent (BOLD) time series and rs-fMRI data. Results indicate that the proposed model can capture both stationary and abrupt brain activity fluctuations. We also compare dFNC patterns between children and young adults from the Philadelphia Neurodevelopmental Cohort (PNC) study. Both spatial and temporal behavior of the dFNC are analyzed and compared. The results provide insight into the developmental trajectory across childhood and motivate further research on brain connectivity.

8.
Hum Brain Mapp ; 40(16): 4843-4858, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31355994

RESUMO

Brain functional connectome analysis is commonly based on population-wise inference. However, in this way precious information provided at the individual subject level may be overlooked. Recently, several studies have shown that individual differences contribute strongly to the functional connectivity patterns. In particular, functional connectomes have been proven to offer a fingerprint measure, which can reliably identify a given individual from a pool of participants. In this work, we propose to refine the standard measure of individual functional connectomes using dictionary learning. More specifically, we rely on the assumption that each functional connectivity is dominated by stable group and individual factors. By subtracting population-wise contributions from connectivity patterns facilitated by dictionary representation, intersubject variability should be increased within the group. We validate our approach using several types of analyses. For example, we observe that refined connectivity profiles significantly increase subject-specific identifiability across functional magnetic resonance imaging (fMRI) session combinations. Besides, refined connectomes can also improve the prediction power for cognitive behaviors. In accordance with results from the literature, we find that individual distinctiveness is closely linked with differences in neurocognitive activity within the brain. In summary, our results indicate that individual connectivity analysis benefits from the group-wise inferences and refined connectomes are indeed desirable for brain mapping.

9.
Sci Rep ; 9(1): 8913, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31222085

RESUMO

High energy X-ray phase contrast tomography is tremendously beneficial to the study of thick and dense materials with poor attenuation contrast. Recently, the X-ray speckle-based imaging technique has attracted widespread interest because multimodal contrast images can now be retrieved simultaneously using an inexpensive wavefront modulator and a less stringent experimental setup. However, it is time-consuming to perform high resolution phase tomography with the conventional step-scan mode because the accumulated time overhead severely limits the speed of data acquisition for each projection. Although phase information can be extracted from a single speckle image, the spatial resolution is deteriorated due to the use of a large correlation window to track the speckle displacement. Here we report a fast data acquisition strategy utilising a fly-scan mode for near field X-ray speckle-based phase tomography. Compared to the existing step-scan scheme, the data acquisition time can be significantly reduced by more than one order of magnitude without compromising spatial resolution. Furthermore, we have extended the proposed speckle-based fly-scan phase tomography into the previously challenging high X-ray energy region (120 keV). This development opens up opportunities for a wide range of applications where exposure time and radiation dose are critical.

10.
J Med Imaging (Bellingham) ; 6(2): 026501, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31001569

RESUMO

Distance correlation is a measure that can detect both linear and nonlinear associations. However, applying distance correlation to imaging genetic studies often needs multiple testing correction due to the large number of multiple inferences. As a result, the sensitivity of its detection may be low. We propose a new model, distance canonical correlation analysis (DCCA), which overcomes this problem by searching a combination of features with the highest distance correlation. This is achieved by constructing a distance kernel function followed by solving a subsequent optimization problem. The ability to detect both linear and nonlinear associations makes DCCA suitable for analyzing complex multimodal and imaging-genetic associations. When applied to a brain imaging-genetic study from the Philadelphia Neurodevelopmental Cohort (PNC), DCCA detected several mental disorder-related gene pathways and brain networks. Experiments on brain connectivity found that the default mode network had strong nonlinear connections with other brain networks. When applied to the study of age effects, DCCA revealed that the connections of brain networks were relatively weak in younger groups but became stronger at older age stages. It indicates that adolescence is a vital stage for brain development. DCCA thus reveals a number of interesting findings and demonstrates a powerful new approach for analyzing multimodal brain imaging data.

11.
IEEE Trans Biomed Eng ; 66(12): 3346-3359, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30872216

RESUMO

OBJECTIVE: Multi-modal functional magnetic resonance imaging has been widely used for brain research. Conventional data-fusion methods cannot capture complex relationship (e.g., nonlinear predictive relationship) between multiple data. This paper aims to develop a neural network framework to extract phenotype related cross-data relationships and use it to study the brain development. METHODS: We propose a novel method, deep collaborative learning (DCL), to address the limitation of existing methods. DCL first uses a deep network to represent original data and then seeks their correlations, while also linking the data representation with phenotypical information. RESULTS: We studied the difference of functional connectivity (FCs) between different age groups and also use FCs as a fingerprint to predict cognitive abilities. Our experiments demonstrated higher accuracy of using DCL over other conventional models when classifying populations of different ages and cognitive scores. Moreover, DCL revealed that brain connections became stronger at adolescence stage. Furthermore, DCL detected strong correlations between default mode network and other networks which were overlooked by linear canonical correlation analysis, demonstrating DCL's ability of detecting nonlinear correlations. CONCLUSION: The results verified the superiority of DCL over conventional data-fusion methods. In addition, the stronger brain connection demonstrated the importance of adolescence stage for brain development. SIGNIFICANCE: DCL can better combine complex correlations between multiple data sets in addition to their fitting to phenotypes, with the potential to overcome the limitations of several current data-fusion models.

12.
Artigo em Inglês | MEDLINE | ID: mdl-30418876

RESUMO

Functional connectivity (FC) within the human brain evaluated through functional magnetic resonance imaging (fMRI) data has attracted increasing attention and has been employed to study the development of the brain or health conditions of the brain. Many different approaches have been proposed to estimate FC from fMRI data, whereas many of them rely on an implicit assumption that functional connectivity should be static throughout the fMRI scan session. Recently, the fMRI community has realized the limitation of assuming static connectivity and dynamic approaches are more prominent in the resting state fMRI (rs-fMRI) analysis. The sliding window technique has been widely used in many studies to capture network dynamics, but has a number of limitations. In this study, we apply a time-varying graphical lasso (TVGL) model, an extension from the traditional graphical lasso, to address the challenge, which can greatly improve the estimation of FC. The performance of estimating dynamic FC is evaluated with the TVGL through both simulated experiments and real rs-fMRI data from the Philadelphia Neurodevelopmental Cohort (PNC) project. Improved performance is achieved over the sliding window technique. In particular, group differences and transition behaviours between young adults and children are investigated using the estimated dynamic connectivity networks, which help us to better unveil the mechanisms underlying the evolution of the brain over time.

13.
J Synchrotron Radiat ; 25(Pt 4): 1182-1188, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29979180

RESUMO

X-ray phase-contrast imaging can substantially enhance image contrast for weakly absorbing samples. The fabrication of dedicated optics remains a major barrier, especially in high-energy regions (i.e. over 50 keV). Here, the authors perform X-ray phase-contrast imaging by using engineered porous materials as random absorption masks, which provides an alternative solution to extend X-ray phase-contrast imaging into previously challenging higher energy regions. The authors have measured various samples to demonstrate the feasibility of the proposed engineering materials. This technique could potentially be useful for studying samples across a wide range of applications and disciplines.

14.
Zhongguo Zhong Yao Za Zhi ; 43(11): 2378-2383, 2018 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-29945394

RESUMO

The loss of hippocampal neurons is one of the main pathological features of Alzheimer's disease (AD), which is related to the apoptosis of hippocampal neurons. Huangpu Tongqiao capsule is used for the treatment of AD, but the underlying mechanism is still unclear. This study is to investigate the mechanism of neuroprotective effect of Huangpu Tongqiao capsule in the treatment of AD, through observing the effect of Huangpu Tongqiao capsule containing serum on cell injury of primary cultured hippocampal neurons induced by Aß25₋35 via inhibiting the cell apoptosis. Primary cultured hippocampal neurons were cultured and identified by MAP-2 immunofluorescence staining, and cell growth state was observed by inverted microscope. The Huangpu Tongqiao capsule containing serum was prepared using the method of serum pharmacology. MTT assays were used to measure the optimum concentration range of Huangpu Tongqiao capsule containing serum, and optimum Aß concentration for establishing the AD model. After primary cultured hippocampal neurons AD cell model was induced by Aß25₋35, cell survival rate was detected by MTT, cell apoptosis rate was assayed by flow cytometry, and protein expressions of Bax, Cyt C and caspase-3 were determined by Western blot analysis. The results showed that the primary cultured hippocampal neurons were cultured successfully, and cells grew mature at seventh days; Compared with normal group, the survival rate of hippocampal neurons in AD cell model group was decreased, the apoptosis rate of hippocampal neurons was increased, and the protein expressions of Bax, Cyt C and caspase-3 were increased (P<0.05, P<0.01); Compared with AD cell model group, the survival rate of hippocampal neurons in Huangpu Tongqiao capsule containing serum group was increased, the apoptosis rate of hippocampal neurons was decreased, and the protein expressions of Bax, Cyt C and caspase-3 were decreased (P<0.05, P<0.01). These findings suggest that Huangpu Tongqiao capsule containing serum has a neuroprotective effect on cell injury of the primary cultured hippocampal neurons induced by Aß25₋35, and its effect on the treatment of AD is associated with the inhibition the apoptosis of hippocampal neurons.


Assuntos
Doença de Alzheimer , Apoptose , Medicamentos de Ervas Chinesas/farmacologia , Neurônios/efeitos dos fármacos , Peptídeos beta-Amiloides , Células Cultivadas , Hipocampo/citologia , Humanos , Fragmentos de Peptídeos
15.
IEEE Trans Med Imaging ; 37(5): 1224-1234, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29727285

RESUMO

Functional connectivity (FC) estimated from functional magnetic resonance imaging (fMRI) time series, especially during resting state periods, provides a powerful tool to assess human brain functional architecture in health, disease, and developmental states. Recently, the focus of connectivity analysis has shifted toward the subnetworks of the brain, which reveals co-activating patterns over time. Most prior works produced a dense set of high-dimensional vectors, which are hard to interpret. In addition, their estimations to a large extent were based on an implicit assumption of spatial and temporal stationarity throughout the fMRI scanning session. In this paper, we propose an approach called dynamic sparse connectivity patterns (dSCPs), which takes advantage of both matrix factorization and time-varying fMRI time series to improve the estimation power of FC. The feasibility of analyzing dynamic FC with our model is first validated through simulated experiments. Then, we use our framework to measure the difference between young adults and children with real fMRI data set from the Philadelphia Neurodevelopmental Cohort (PNC). The results from the PNC data set showed significant FC differences between young adults and children in four different states. For instance, young adults had reduced connectivity between the default mode network and other subnetworks, as well as hyperconnectivity within the visual system in states 1 and 3, and hypoconnectivity in state 2. Meanwhile, they exhibited temporal correlation patterns that changed over time within functional subnetworks. In addition, the dSCPs model indicated that older people tend to spend more time within a relatively connected FC pattern. Overall, the proposed method provides a valid means to assess dynamic FC, which could facilitate the study of brain networks.


Assuntos
Mapeamento Encefálico/métodos , Encéfalo/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Rede Nervosa/diagnóstico por imagem , Adolescente , Adulto , Algoritmos , Encéfalo/anatomia & histologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Rede Nervosa/anatomia & histologia , Adulto Jovem
16.
Zhongguo Zhong Yao Za Zhi ; 43(3): 571-576, 2018 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-29600624

RESUMO

Genistein is a kind of isoflavone compounds, also called phytoestrogens, with clinical effects on cardiovascular disease, cancer and postmenopausal-related gynecological diseases, and also has the potentiality in the prevention and treatment of Alzheimer's disease(AD). In this study, the protective effect of genistein on Aß25₋35-induced PC12 cell injury and effect on CaM-CaMKIV signaling pathway were observed to investigate its mechanism for AD. PC12 cells were cultured in vitro and then the safe concentration of genistein and the modeling concentration and optimal time point of administration of Aß25₋35 were screened by MTT assay. After being pretreated with different concentrations of genistein(25, 50, 100 µmol·L⁻¹) on PC12 cells, the AD model of PC12 cells was induced by Aß25₋35. Then the survival rate of cells was detected by MTT assay; morphological change of cells was observed under the inverted microscope, and apoptosis of cells was assessed by AO/EB fluorescence staining; the neuroprotective effects of genistein on AD cell model were observed and the optimal concentration of genistein was determined. Expressions of mRNA and protein levels of CaM, CaMKK, CaMKIV and tau were detected by qRT-PCR and Western blot assay, respectively. The results showed that as compared with the blank group, the cell survival rate was decreased; the cell damage and apoptosis were increased; and the expressions of mRNA and protein levels of CaM, CaMKK, CaMKIV and tau were increased in AD model group. Genistein could significantly improve the cell survival rate, reduce the cell damage and apoptosis of AD cell model, and significantly down-regulate the expressions of mRNA and protein levels of CaM, CaMKK, CaMKIV and tau of AD cell model. These results indicated that genistein has obviously neuroprotective effect on the AD cell model induced by Aß25₋35, and the mechanism may be related to the down-regulation of CaM-CaMKIV signaling pathway and Tau protein expression.


Assuntos
Peptídeos beta-Amiloides , Proteína Quinase Tipo 4 Dependente de Cálcio-Calmodulina/metabolismo , Calmodulina/metabolismo , Genisteína/farmacologia , Fragmentos de Peptídeos , Substâncias Protetoras/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose , Sobrevivência Celular , Células PC12 , Ratos
17.
Neural Regen Res ; 12(9): 1479-1484, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29089994

RESUMO

Genistein has a neuroprotective effect in Alzheimer's disease, but its mechanism of action needs further clarification. Accumulating evidence suggests that excessive phosphorylation of tau protein causes production of neurofibrillary tangles, which is one of the main pathological characteristics of Alzheimer's disease, and tau protein can be phosphorylated by calcium/calmodulin dependent protein kinase IV (CAMK4). After 7 days of pre-administration of genistein (90 mg/kg), an Alzheimer's disease rat model was established using an intraperitoneal injection of D-galactose combined with an intracerebral injection of amyloid-ß peptide (25-35). The rat was then continuously administered genistein (90 mg/kg) for 42 days. The Morris water maze test, western blotting and hematoxylin-eosin staining results showed that genistein significantly decreased the escape latency and increased the number of times crossing the platform, reduced p-tau, CALM, CAMKK1 and p-CAMK4 protein levels in the hippocampus, and alleviated hippocampal neuron damage. These findings indicate that genistein may play a neuroprotective role in Alzheimer's disease through regulating CAMK4 to modulate tau hyperphosphorylation.

18.
PLoS One ; 12(7): e0181792, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28759589

RESUMO

Recently, many image processing applications have taken advantage of a psychophysical and neurophysiological mechanism, called "surround suppression" to extract object contour from a natural scene. However, these traditional methods often adopt a single suppression model and a fixed input parameter called "inhibition level", which needs to be manually specified. To overcome these drawbacks, we propose a novel model, called "context-adaptive surround suppression", which can automatically control the effect of surround suppression according to image local contextual features measured by a surface estimator based on a local linear kernel. Moreover, a dynamic suppression method and its stopping mechanism are introduced to avoid manual intervention. The proposed algorithm is demonstrated and validated by a broad range of experimental results.


Assuntos
Sensibilidades de Contraste , Processamento de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão , Algoritmos , Inteligência Artificial , Modelos Estatísticos , Dinâmica não Linear , Distribuição Normal , Propriedades de Superfície
19.
Neural Regen Res ; 11(7): 1153-8, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27630702

RESUMO

Genistein is effective against amyloid-ß toxicity, but the underlying mechanisms are unclear. We hypothesized that genistein may protect neurons by inhibiting the mitochondrial apoptotic pathway, and thereby play a role in the prevention of Alzheimer's disease. A rat model of Alzheimer's disease was established by intraperitoneal injection of D-galactose and intracerebral injection of amyloid-ß peptide (25-35). In the genistein treatment groups, a 7-day pretreatment with genistein (10, 30, 90 mg/kg) was given prior to establishing Alzheimer's disease model, for 49 consecutive days. Terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling assay demonstrated a reduction in apoptosis in the hippocampus of rats treated with genistein. Western blot analysis showed that expression levels of capase-3, Bax and cytochrome c were decreased compared with the model group. Furthermore, immunohistochemical staining revealed reductions in cytochrome c and Bax immunoreactivity in these rats. Morris water maze revealed a substantial shortening of escape latency by genistein in Alzheimer's disease rats. These findings suggest that genistein decreases neuronal loss in the hippocampus, and improves learning and memory ability. The neuroprotective effects of genistein are associated with the inhibition of the mitochondrial apoptotic pathway, as shown by its ability to reduce levels of caspase-3, Bax and cytochrome c.

20.
Sci Rep ; 6: 30581, 2016 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-27466217

RESUMO

High energy X-ray imaging has unique advantage over conventional X-ray imaging, since it enables higher penetration into materials with significantly reduced radiation damage. However, the absorption contrast in high energy region is considerably low due to the reduced X-ray absorption cross section for most materials. Even though the X-ray phase and dark-field imaging techniques can provide substantially increased contrast and complementary information, fabricating dedicated optics for high energies still remain a challenge. To address this issue, we present an alternative X-ray imaging approach to produce transmission, phase and scattering signals at high X-ray energies by using a random absorption mask. Importantly, in addition to the synchrotron radiation source, this approach has been demonstrated for practical imaging application with a laboratory-based microfocus X-ray source. This new imaging method could be potentially useful for studying thick samples or heavy materials for advanced research in materials science.

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