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With increasingly strict regulations regarding patient exposure, research on digital radiography technology has recently focused on indirect methods that can produce high-quality images for a low radiation dose. In particular, medical imaging systems based on indirect methods universally use rare-earth metal phosphors, because of their high atomic number and excellent luminescence efficiency. Thus, various studies aiming to improve the luminescence efficiency of phosphors have been conducted. Despite this research, however, the current luminescence efficiencies are insufficient. Here, we report a basic study aiming to develop a phosphor screen containing a three-quarter-wave optical-thickness layer to improve the light transmission efficiency. Specifically, the fabrication and measurement of a Gd2O2S:Tb phosphor screen containing a single three-quarter-wave optical-thickness layer is presented. The screen is fabricated via a screen-printing and spin-coating method. Based on histograms of the degree of luminescence and the pixel values, we demonstrate that the light transmission efficiency is improved by the three-quarter-wave optical-thickness layer. Note that analysis of the full width at half maximum of the pixel value distribution reveals the possibility of resolution loss when obtaining medical images. Overall, the results of this study confirm that the light transmission efficiency can be improved through use of a single-layer anti-reflection coating. However, because the emission spectrum of the Gd2O2S:Tb screen is in the 480-600-nm band, it is necessary to expand the areas exhibiting the lowest reflectance to the wavelengths at the edge of this band. Thus, further study should be conducted to optimize the optical thickness.
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PURPOSE: This study suggests a noninvasive and repetitive measurement method using 1 H magnetic resonance spectroscopy to monitor changes in cellular metabolites within a single sample. METHODS: Longitudinal acquisition of cellular metabolites from three-dimensional cultured human osteosarcoma (MG-63) cells was conducted using 3.0 Tesla 1 H MRS for 2 weeks at three time points: days 1, 7, and 14. During the MR spectroscopy (MRS) scan, cell specimen temperatures were kept constant at 37°C by a lab-developed magnetic resonance compatible thermostatic device. A DNA assay and live/dead staining of the cell specimens were carried out at each time point to verify the MRS measurements. RESULTS: Cell viability in the proposed device did not significantly differ from that of cells in a conventional incubator (P = 0.946). Cell proliferation and choline concentration increased during the first week, but remained constant during the second week. Lactate did not change during the first week, but increased during the second week. Likewise, cell viability remained constant until day 7, then decreased. CONCLUSION: The proposed MRS technique results in a survivable environment for longitudinal studies of cells and provides a new way to measure metabolomic changes over time in single specimens of cells. Magn Reson Med 76:1912-1918, 2016. © 2016 International Society for Magnetic Resonance in Medicine.
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Algoritmos , Imagem Molecular/instrumentação , Proteínas de Neoplasias/metabolismo , Osteossarcoma/metabolismo , Espectroscopia de Prótons por Ressonância Magnética/instrumentação , Linhagem Celular Tumoral , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Imagem Molecular/métodos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
AIMS: The aim of the present study was to investigate whether the effects of vitamin B12 and homocysteine on brain volume are influenced by apolipoprotein E (APOE) genotype. We examined the effects in each subgroup (APOE ε4 carriers and non-carriers) of Alzheimer's disease (AD) patients and healthy normal controls. METHODS: Forty participants with AD and 20 healthy normal controls were recruited from memory impairment clinics at Pusan National University Hospital in Korea. All participants were APOE genotyped and underwent magnetic resonance imaging, including 3-D volumetric images for grey matter (GM) volume. A multiple regression model integrated into statistical parametric mapping was used to see if there was any correlation between vitamin B12 or homocysteine and GM volume in each subgroup (APOE ε4 carriers and non-carriers) of AD patients and healthy normal controls. RESULTS: There was a significant positive correlation between serum concentrations of vitamin B12 and regional GM volume in APOE ε4 carriers with AD but not in non-carriers. We also found that there was a significant negative correlation between serum concentrations of homocysteine and regional GM volume in APOE ε4 non-carriers with AD but not in carriers (P < 0.001, uncorrected for multiple comparisons; extent threshold = 100 voxel). CONCLUSION: The present findings suggest that the effects of vitamin B12 and homocysteine on GM volume might be influenced by APOE genotype.
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Doença de Alzheimer/genética , Apolipoproteína E4/genética , Substância Cinzenta/patologia , Homocisteína/sangue , Vitamina B 12/sangue , Idoso , Doença de Alzheimer/patologia , Apolipoproteína E4/sangue , Estudos de Casos e Controles , Feminino , Genótipo , Substância Cinzenta/metabolismo , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , República da CoreiaRESUMO
BACKGROUND: We evaluated the cortical morphology in patients with orthostatic intolerance. METHODS: Thirty patients with orthostatic intolerance, as well as age- and sex-matched normal controls, were enrolled in this study. We divided the patients into orthostatic hypotension (n = 22) and postural tachycardia syndrome (n = 8) groups based on their response to a head-up tilt table test. We analyzed whole-brain T1-weighted MRI images using FreeSurfer 5.1. The measures of cortical morphology were compared between the groups. RESULTS: The cortical thickness in the right hemisphere, including the medial orbitofrontal, peri-calcarine, post-central, inferior temporal, and lateral occipital cortex, and in the peri-calcarine cortex of the left hemisphere was thinned in patients with orthostatic hypotension compared to normal controls. The other measures of cortical morphology, including the surface area, volume, and curvatures, did not differ between patients with orthostatic hypotension and normal controls. However, none of the measures of cortical morphology differed between patients with postural tachycardia syndrome and normal controls. CONCLUSIONS: We demonstrated that the cortical morphology significantly changed in patients with orthostatic hypotension but not in patients with postural tachycardia syndrome compared to normal controls. These findings support the hypothesis that orthostatic intolerance is a heterogeneous syndrome.
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Córtex Cerebral/patologia , Intolerância Ortostática/patologia , Adulto , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Postura/fisiologia , Teste da Mesa InclinadaRESUMO
AIMS: An association between white matter hyperintensities (WMH) and cognitive dysfunction has long been recognized. However, subjects with identically appearing WMH on magnetic resonance imaging present with a wide variance in cognitive function ranging from normal cognition to dementia. The aim of this study was to compare cortical atrophy and integrity of white matter of patients with subcortical vascular dementia of Binswanger type (SVaD-BT) with those of the normal cognition group with WMH (ncWMH). METHODS: Eleven patients with SVaD-BT and 11 age-, sex-, education- and grade of WMH-matched ncWMH underwent magnetic resonance imaging, including 3-D volumetric images for cortical atrophy and diffusion tensor imaging for integrity of white matter. RESULTS: Compared to ncWMH, SVaD-BT patients showed cortical atrophies in frontal (i.e. frontal pole, precentral gyrus and frontal medial cortex) and occipital areas (i.e. lingual gyrus) followed by atrophies in temporal (i.e. fusiform cortex and middle temporal gyrus) areas. Along with cortical atrophies, reduced integrity with low fractional anisotropy and high mean diffusivity values in genu and splenium of the corpus callosum were detected in SVaD-BT patients. CONCLUSIONS: Our findings suggest that cognitive decline from ncWMH to SVaD-BT may be associated with cortical atrophy and reduced integrity of white matter.
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Córtex Cerebral/patologia , Transtornos Cognitivos/patologia , Demência Vascular/patologia , Substância Branca/patologia , Idoso , Atrofia/patologia , Transtornos Cognitivos/etiologia , Demência Vascular/complicações , Imagem de Tensor de Difusão , Feminino , Humanos , Imageamento por Ressonância Magnética , MasculinoRESUMO
BACKGROUND: To observe brain activation induced by functional electrical stimulation, voluntary contraction, and the combination of both using functional magnetic resonance imaging (fMRI). METHODS: Nineteen healthy young men were enrolled in the study. We employed a typical block design that consisted of three sessions: voluntary contraction only, functional electrical stimulation (FES)-induced wrist extension, and finally simultaneous voluntary and FES-induced movement. MRI acquisition was performed on a 3.0 T MR system. To investigate activation in each session, one-sample t-tests were performed after correcting for false discovery rate (FDR; p < 0.05). To compare FES-induced movement and combined contraction, a two-sample t-test was performed using a contrast map (p < 0.01). RESULTS: In the voluntary contraction alone condition, brain activation was observed in the contralateral primary motor cortex (MI), thalamus, bilateral supplementary motor area (SMA), primary sensory cortex (SI), secondary somatosensory motor cortex (SII), caudate, and cerebellum (mainly ipsilateral). During FES-induced wrist movement, brain activation was observed in the contralateral MI, SI, SMA, thalamus, ipsilateral SII, and cerebellum. During FES-induced movement combined with voluntary contraction, brain activation was found in the contralateral MI, anterior cingulate cortex (ACC), SMA, ipsilateral cerebellum, bilateral SII, and SI.The activated brain regions (number of voxels) of the MI, SI, cerebellum, and SMA were largest during voluntary contraction alone and smallest during FES alone. SII-activated brain regions were largest during voluntary contraction combined with FES and smallest during FES contraction alone. The brain activation extent (maximum t score) of the MI, SI, and SII was largest during voluntary contraction alone and smallest during FES alone. The brain activation extent of the cerebellum and SMA during voluntary contraction alone was similar during FES combined with voluntary contraction; however, cerebellum and SMA activation during FES movement alone was smaller than that of voluntary contraction alone or voluntary contraction combined with FES. Between FES movement alone and combined contraction, activated regions and extent due to combined contraction was significantly higher than that of FES movement alone in the ipsilateral cerebellum and the contralateral MI and SI. CONCLUSIONS: Voluntary contraction combined with FES may be more effective for brain activation than FES-only movements for rehabilitation therapy. In addition, voluntary effort is the most important factor in the therapeutic process.
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Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Estimulação Elétrica , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Adulto , Humanos , Imageamento por Ressonância Magnética , Masculino , Músculo Esquelético/inervaçãoRESUMO
OBJECTIVE: To investigate the association of the APOE ε4 genotype with hippocampal volume, independent of Aß burden. METHOD: This cross-sectional study included 71 participants with mild cognitive impairment or mild AD. All participants were divided into carriers or non-carriers of the ε4 allele. The main outcome was hippocampal volume measured using structural magnetic resonance imaging; 18F-florbetaben positron emission tomography was additionally performed to investigate the association of APOE ε4 genotype with hippocampal volumes, independently of Aß burden. Analysis of covariance was conducted to compare the differences in hippocampal volumes between carriers and non-carriers of the ε4 allele after controlling for global Aß burden or local hippocampal Aß burden. RESULTS: The APOE ε4 genotype was associated with a smaller right and total hippocampal volume (right: 3160.16 ± 365.71 vs. 3365.24 ± 434.88, p < 0.05; total: 6257.48 ± 790.60 vs. 6599.52 ± 840.58, p < 0.05), independent of Aß burden. CONCLUSION: Our findings on the association of APOEε4 genotype with hippocampal volume independent of Aß burden suggest that the APOEε4 genotype may contribute to hippocampal neurodegeneration through an Aß-independent mechanism.
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Doença de Alzheimer , Apolipoproteína E4 , Hipocampo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides , Apolipoproteína E4/genética , Estudos Transversais , Hipocampo/patologia , HumanosRESUMO
Milnacipran is a reuptake inhibitor of both serotonin and noradrenaline, used in the treatment of fibromyalgia with severe depression. However, few studies have been conducted on the efficacies of milnacipran drug on the functional connectivity of the neural network. The authors aimed to find the correlation between the drug efficacy and the changes in neural network in fibromyalgia patients. Resting-state-functional magnetic resonance imaging (rs-fMRI) were obtained before and after milnacipran drug administration. Graph theory indexes and small-worldness were calculated using preprocessed blood-oxygen-level-dependent signals from the rs-fMRI scans of 14 brain regions-of-interest. Statistical analyses were conducted to compare the topological network parameters. Significant changes in the neural network indexes appeared in three of the 14 brain regions-of-interest. In the pain network, the average path length on the left side of Brodmann area 32 was shortened. In the default mode network, functional connectivity changes were observed in the left lateral parietal cortex and medial prefrontal cortex. In the left lateral parietal cortex, the degree and betweenness centrality increased, whereas the clustering coefficient decreased. In the medial prefrontal cortex, local efficiency decreased. The small-worldness declined after milnacipran medication. The present results demonstrate that functional connectivity indexes in the brains of female fibromyalgia patients obtained from rs-fMRI data can be used as potential prognosis markers of milnacipran drug treatment.
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Phosphor screens have attracted increasing global interest because they can aid the acquisition of high-quality images while simultaneously reducing exposure. However, although increasing the thickness of the phosphor screen increases exposure efficiency due to scattered light, it also leads to a broader light spread, which results in poorer resolution. Hence, in this study, we implemented a reflector using a mirror-coating technique on the surface of a phosphor screen and analyzed its characteristics in terms of luminescence intensity and resolution. We present the fabrication and measurement of the phosphor screen based on a reflector containing Gd2O2S:Tb. The phosphor screen containing the reflector can be fabricated via the screen-printing method and roll-to-roll sputtering method. In particular, when compared to the condition without a reflector, Al and Cu reflectors showed improvements in luminescence intensity of 15.7% and 12.2%, respectively, as well as lower full widths at half maximum of 11.45 and 9.08, respectively. This quantitatively demonstrates that Cu and Al are suitable reflector materials to improve exposure efficiency while maintaining resolution in radiography systems. Moreover, because we did not utilize an optical assembly, which improves the transmission efficiency by matching the different refractive indices of the phosphor screen and photo-detector, we believe that the quantity of photons could be further improved if the reflectors were applied to a commercial product. Thus, future studies using single-layer anti-reflector coating techniques with optical assemblies are warranted.
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Objectives: To validate a visual rating scale reflecting sub-regional patterns of putaminal hypointensity in susceptibility-weighted imaging of patients with multiple system atrophy (MSA). Methods: Using a visual rating scale (from G0 to G3), 2 examiners independently rated putaminal hypointensities of 37 MSA patients and 21 control subjects. To investigate the correlation with the scales, R2* values and the volume of the entire putamen were measured. Results: MSA patients with parkinsonian variant had significantly higher scores than those with cerebellar variant. Visual rating scores in MSA were correlated with R2* values [General estimating equation (GEE), Wald chi-square = 25.89, corrected p < 0.001] and volume (Wald chi-square = 75.44, corrected p < 0.001). They correlated with UPDRS motor scores. Binary logistic regression analyses revealed that the visual rating scale was a significant predictor for discriminating MSA patients from controls [multivariate model adjusted for age and sex, odds ratio 52.722 (corrected p = 0.009)]. Pairwise comparison between areas under the curve (AUCs) revealed that the visual rating scale demonstrated higher accuracy than R2* values [difference between AUCs; univariate model = 0.247 (corrected p < 0.001); multivariate model = 0.186 (corrected p = 0.003)]. There were no significant differences in clinical characteristics between the high-iron group, defined as putamen with visual rating scale ≥ G2 and R2* values ≥ third quartile, and the remaining patients. Conclusion: The visual rating scale, which reflects quantitative iron content and atrophy of the putamen as well as motor severities, could be useful for the discrimination and evaluation of patients with MSA.
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BACKGROUND & OBJECTIVE: Although iron accumulation is thought to be associated with neurodegenerative processes, the timing of putaminal iron deposition during the disease course of multiple system atrophy (MSA) remains unclear. We sought to investigate the temporal pattern of iron deposition in the putamen of MSA patients by calculating the conditional probabilities (CPs) of multimodal MRI changes. METHODS: We simultaneously measured putaminal R2*, volume and MD values of 39 probable MSA patients and 22 control subjects. The presence of significant MRI changes was defined as higher R2* and MD values, or lower volumes than cut-off values derived from mean values in control putamen. The CPs of R2* changes without MD or volume changes were then compared with those of MD or volume changes without R2* changes. RESULTS: Regardless of the cut-off values, the CPs of R2* increments without MD or volume changes were significantly lower than those for MD or volume changes without R2* increments. The associations of R2* with volume and MD values appeared in non-linear exponential and quadratic patterns, respectively. CONCLUSIONS: Our findings suggest that putaminal iron accumulation would occur under volume atrophy or MD increments. Thus, iron deposition in the putamen of MSA patients is likely a secondary byproduct of neurodegeneration.
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Ferro , Modelos Neurológicos , Atrofia de Múltiplos Sistemas/patologia , Degeneração Neural/patologia , Putamen/patologia , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/métodos , Atrofia de Múltiplos Sistemas/complicações , Atrofia de Múltiplos Sistemas/diagnóstico por imagem , Degeneração Neural/diagnóstico por imagem , Degeneração Neural/etiologia , Putamen/diagnóstico por imagemRESUMO
OBJECTIVE: The variability of the severity and regional distribution of pathological process in basal ganglia (BG) and brainstem-cerebellar systems results in clinical heterogeneity and represents the motor subtype of multiple system atrophy (MSA). This study aimed to quantify spatial patterns of multimodal MRI abnormalities in BG and stem-CB regions and define structural MRI findings that correlate with clinical characteristics. METHODS: We simultaneously measured R2*, mean diffusivity (MD), and volume in the subcortical structures (BG, thalamus, brainstem-cerebellar regions) of 39 probable MSA and 22 control subjects. Principal component analysis (PCA) and structural equation modeling (SEM) were performed to show a model consisting of multiple inter-dependencies. RESULTS: Structural MRI alterations were found to be significantly interrelated within BG as well as brainstem-cerebellar regions in MSA patients. PCA extracted four factors: three factors reflected alterations in R2*, MD and volume of the BG region including the caudate nucleus, putamen, and pallidum, and the remaining one factor represented degenerative changes in MD and volume of stem-CB region. In SEM, a latent variable reflecting brainstem-cerebellar degeneration did not show a significant correlation with the other latent variables associated with BG degeneration. Putaminal MD values and a PCA-driven factor reflecting MD values in the BG showed a significant correlation with UPDRS and UMSARS scores. CONCLUSION: Multimodal structural MRI abnormalities in MSA appear to be segregated into BG and stem-CB-related factors that can be associated with the clinical phenotype and motor severity.
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Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Atrofia de Múltiplos Sistemas/diagnóstico por imagem , Idoso , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Estatística como Assunto , Estatísticas não ParamétricasRESUMO
The thalamus plays an important role in the modulation of both focal and generalized seizures, but the mechanisms related to seizures may be different among epilepsy syndromes. The aim of this study is to investigate the thalamic atrophy in different epilepsy syndromes. We enrolled a total of 72 patients with epilepsy (22 patients with temporal lobe epilepsy with hippocampal sclerosis, 21 patients with extra-temporal lobe epilepsy, and 29 patients with juvenile myoclonic epilepsy). We analyzed structural volumes of the brain with FreeSurfer 5.1 software, and compared them among subgroups of epilepsy and normal control subjects. Moreover, we quantified correlations between the duration of epilepsy and the structural volumes with age and sex as covariates. The volumes of the ipsilateral hippocampus in temporal lobe epilepsy with hippocampal sclerosis were significantly smaller than those in extra-temporal lobe epilepsy and normal control subjects [analysis of variance (ANOVA), pâ¯<â¯0.001]. Although the volumes of the ipsilateral thalamus were not different from those of normal control subjects, the volumes of the ipsilateral thalamus were negatively correlated with duration of epilepsy in temporal lobe epilepsy with hippocampal sclerosis (râ¯=â¯-0.5, pâ¯=â¯0.02). However, the volumes of interest in extra-temporal lobe epilepsy and juvenile myoclonic epilepsy were not different from those in normal control subjects, and none of these structures were correlated with duration of epilepsy. These findings suggest that the role of the thalamus may be different in thalamo-limbic circuits among epilepsy syndromes.
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Epilepsia do Lobo Temporal/patologia , Tálamo/patologia , Adulto , Atrofia/patologia , Feminino , Hipocampo/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose/patologiaRESUMO
Although juvenile myoclonic epilepsy has been considered as a disorder of thalamo-cortical circuit, it is not determined the causality relationship between thalamus and cortex. The aim of this study was to evaluate whether juvenile myoclonic epilepsy is a disorder of thalamus or cortex. Twenty-nine patients with juvenile myoclonic epilepsy and 20 normal controls were enrolled in this study. In addition, we included 10 patients with childhood absence epilepsy as a disease control group. Using whole-brain T1-weighted MRIs, we analyzed the volumes of the structures, including hippocampus, thalamus, and total cortex, with FreeSurfer 5.1. We also investigated the effective connectivity among these structures using SPSS Amos 21 based on these volumetric measures. The structural volumes in juvenile myoclonic epilepsy were not different from those in normal controls. There was a statistically significant effective connectivity from the total cortex to the thalamus in the patients with juvenile myoclonic epilepsy. In addition, a significant effective connectivity from the hippocampus to the ipsilateral thalamus was revealed. Unlike the patients with juvenile myoclonic epilepsy, neither the patients with childhood absence epilepsy nor normal controls had a significant effective connectivity from the total cortex to the thalamus or from the thalamus to the cortex. The connectivity of brain in patients with juvenile myoclonic epilepsy could be different from that in patients with childhood absence epilepsy, and the cortex rather than the thalamus might play a critical role in the pathogenesis of juvenile myoclonic epilepsy.
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Córtex Cerebral/patologia , Epilepsia Mioclônica Juvenil/patologia , Tálamo/patologia , Adolescente , Adulto , Idade de Início , Idoso , Córtex Cerebral/diagnóstico por imagem , Criança , Pré-Escolar , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Modelos Neurológicos , Epilepsia Mioclônica Juvenil/diagnóstico por imagem , Vias Neurais/diagnóstico por imagem , Vias Neurais/patologia , Tálamo/diagnóstico por imagem , Adulto JovemRESUMO
Tendon and ligament (T/L) have been known to be obviously different from each other in tissue level. However, due to the overlapping gene markers, distinction in cellular level has not been clearly verified yet. Recently, the use of nuclear magnetic resonance (NMR) spectroscopy has shown the potential to detect biological markers in cellular level. Therefore, in this study we applied a non-invasive technique based on NMR spectroscopy to establish biomarkers to distinguish between T/L fibroblasts. In addition the cellular morphologies and gene expression patterns were also investigated for comparison through optical microscopy and real-time polymerase chain reaction (PCR). No difference was observed from morphology and real-time PCR results, either as expected. However, we found clear differences in their metabolomic spectra using 1H NMR spectroscopy. The calculated integral values of fatty acids (with chemical shifts at ~0.9, 1.26, 1.59, 2.05, 2.25, and 2.81 ppm), lactate (~1.33 ppm), and leucine (~2.72 ppm) were significantly different between the two types of fibroblasts. To be specific tendon group exhibited higher level of the metabolite than ligament group. In conclusion, in-cell metabolomic evaluation by NMR technique used in this study is believed to provide a promising tool in distinguishing cell types, especially T/L cells, which cannot be classified by conventional biological assays.
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OBJECTIVE: The aim of this study is to compare gray matter (GM) volume and white matter (WM) integrity in Apolipoprotein E4 (ApoE ε4) carriers with that of ApoE ε4 noncarriers using the voxel-based morphometry and diffusion tensor imaging (DTI) to investigate the effect of the ApoE ε4 on brain structures in subjective memory impairment (SMI) without white matter hyperintensities (WMH). METHODS: Altogether, 26 participants with SMI without WMH were finally recruited from the Memory impairment clinics of Pusan National University Hospital in Korea. All participants were ApoE genotyped (ApoE ε4 carriers: n = 13, matched ApoE ε4 noncarriers: n = 13) and underwent 3-tesla magnetic resonance imaging (MRI) including 3-dimensional volumetric images for GM volume and DTI for WM integrity. RESULTS: ApoE ε4 carriers compared with noncarriers in SMI without WMH showed the atrophy of GM in inferior temporal gyrus, inferior parietal lobule, anterior cingulum, middle frontal gyrus, and precentral gyrus and significantly lower fractional anisotropy WM values in the splenium of corpus callosum and anterior corona radiate. CONCLUSION: Our findings suggest that the ApoE ε4 is associated with both atrophy of GM volume and disruption of WM integrity in SMI without WMH.
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Apolipoproteína E4/genética , Encéfalo/patologia , Genótipo , Substância Cinzenta/patologia , Transtornos da Memória/patologia , Substância Branca/patologia , Idoso , Encéfalo/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética/métodos , Masculino , Transtornos da Memória/diagnóstico por imagem , Transtornos da Memória/genética , Pessoa de Meia-Idade , Tamanho do Órgão/genética , Substância Branca/diagnóstico por imagemRESUMO
The purpose of this study was to investigate the association between brain regional gray matter volume and two subtypes of psychotic symptoms, namely paranoid and misidentification subtypes, in antipsychotic-naïve mild or moderate Alzheimer's disease (AD) patients. Forty AD patients with psychotic symptoms and 25 AD patients without psychotic symptoms were assessed for cognitive and functional impairment. Presence and subtype of psychotic symptoms were assessed by using the delusion and hallucination subscale of the Korean Neuropsychiatric Inventory (K-NPI). Structural MRI images were acquired on a 3 T scanner, and were analyzed using voxel-based morphometry (VBM) for automated analysis. The misidentification subtype is associated with more severe gray matter atrophy, and paranoid subtype is associated with less severe gray matter atrophy compared to non-psychosis group. These results suggest that the misidentification, the paranoid subtype and the non-psychosis group have a distinct neural correlation.
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Doença de Alzheimer/patologia , Substância Cinzenta/patologia , Imageamento por Ressonância Magnética/métodos , Transtornos Psicóticos/patologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/psicologia , Atrofia/diagnóstico por imagem , Estudos de Casos e Controles , Delusões/diagnóstico por imagem , Delusões/patologia , Feminino , Substância Cinzenta/diagnóstico por imagem , Alucinações/diagnóstico por imagem , Alucinações/patologia , Humanos , Masculino , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/psicologiaRESUMO
OBJECTIVE: The purpose of this study was to determine whether gray matter volumes are associated with treatment response of psychotic symptoms in Alzheimer's disease (AD) patients. METHOD: Risperidone, which is commonly used as an atypical antipsychotic drug, was administered in a clinical setting for 6 weeks from April 2012 to February 2013 to 25 antipsychotic-naïve AD patients with psychosis, diagnosed according to Jeste and Finkel's proposed diagnostic criteria for psychosis of Alzheimer's disease. Psychotic symptoms were rated with the Korean version of the Neuropsychiatric Inventory (K-NPI) at baseline and at 6 weeks, and treatment response was defined as the change in K-NPI score from baseline to 6 weeks. Gray matter volumes were measured with magnetic resonance imaging and voxel-based morphometry at baseline. Age, gender, years of education, total intracranial volume, apolipoprotein E genotype, dosage of risperidone, the baseline scores on the Korean version of the Mini-Mental State Examination, and the baseline psychotic and nonpsychotic symptoms scores on the K-NPI were measured as covariates of no interest. RESULTS: We found that treatment response of psychotic symptoms to risperidone in antipsychotic-naïve AD patients was positively associated with both left and right putamina, left parahippocampal gyrus, and left amygdala volume after controlling covariates of no interest (uncorrected P < .001, KE > 100 voxels). CONCLUSIONS: Therefore, we conclude that gray matter volumes of putamina, left parahippocampal gyrus, and left amygdala are associated with treatment response of psychotic symptoms after 6 weeks of treatment with risperidone in antipsychotic-naïve AD patients with psychosis. These results suggest that the volumes of specific gray matter regions probably contribute to treatment response of psychotic symptoms in AD patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01198093.
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Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Substância Cinzenta/efeitos dos fármacos , Substância Cinzenta/patologia , Transtornos Psicóticos/tratamento farmacológico , Risperidona/uso terapêutico , Idoso , Doença de Alzheimer/complicações , Doença de Alzheimer/psicologia , Tonsila do Cerebelo/patologia , Antipsicóticos/uso terapêutico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Neuroimagem , Giro Para-Hipocampal/patologia , Transtornos Psicóticos/complicações , Transtornos Psicóticos/psicologia , Putamen/patologia , Resultado do TratamentoRESUMO
PURPOSE: A reference reagent, 3-(trimethylsilyl) propionic-2, 2, 3, 3-d4 acid sodium (TSP), has been used frequently in nuclear magnetic resonance (NMR) and magnetic resonance spectroscopy (MRS) as an internal reference to identify cell and tissue metabolites, and determine chemical and protein structures. This reference material has been exploited for the quantitative and dynamic analyses of metabolite spectra acquired from cells. The aim of this study was to evaluate the cytotoxicity of TSP on three-dimensionally, agarose gel, cultured cells. MATERIALS AND METHODS: A human osteosarcoma cell line (MG-63) was selected, and cells were three dimensionally cultured for two weeks in an agarose gel. The culture system contained a mixture of conventional culture medium and various concentrations (0, 1, 3, 5, 7, 10, 20 30 mM) of TSP. A DNA quantification assay was conducted to assess cell proliferation using Quant-iT PicoGreen dsDNA reagent and kit, and cell viability was determined using a LIVE/DEAD Viability/Cytotoxicity kit. Both examinations were performed simultaneously at 1, 3, 7 and 14 days from cell seeding. RESULTS: In this study, the cytotoxicity of TSP in the 3D culture of MG-63 cells was evaluated by quantifying DNA (cell proliferation) and cell viability. High concentrations of TSP (from 10 to 30 mM) reduced both cell proliferation and viability (to 30% of the control after one week of exposure), but no such effects were found using low concentrations of TSP (0-10 mM). CONCLUSIONS: This study shows that low concentrations of TSP in 3D cell culture medium can be used for quantitative NMR or MRS examinations for up to two weeks post exposure.
Assuntos
Osteócitos/efeitos dos fármacos , Propionatos/toxicidade , Compostos de Trimetilsilil/toxicidade , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Propionatos/efeitos adversos , Compostos de Trimetilsilil/efeitos adversosRESUMO
Magnetic resonance imaging (MRI) can be useful not only for the diagnosis of multiple system atrophy (MSA) itself, but also to distinguish between different clinical subtypes. This study aimed to investigate whether there are differences in the progression of subcortical atrophy and iron deposition between two variants of MSA. Two serial MRIs at baseline and follow-up were analyzed in eight patients with the parkinsonian variant MSA (MSA-P), nine patients with cerebellar variant MSA (MSA-C), and fifteen patients with Parkinson's disease (PD). The R2* values and volumes were calculated for the selected subcortical structures (caudate nucleus, putamen, globus pallidus, and thalamus) using an automated region-based analysis. In both volume and R2*, a higher rate of progression was identified in MSA-P patients. Volumetric analysis showed significantly more rapid progression of putamen and caudate nucleus in MSA-P than in MSA-C. With regard to R2* changes, a significant increase at follow-up and a higher rate of progression were identified in the putamen of MSA-P group compared to MSA-C and PD groups. This longitudinal study revealed different progression rates of MRI markers between MSA-P and MSA-C. Iron-related degeneration in the putamen may be more specific for MSA-P.