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BACKGROUND: T1-weighted (T1W) magnetic resonance imaging (MRI) using the delay alternating with nutation for excitation-sampling perfection with application-optimized contrasts using different flip angle evolution (DANTE-SPACE) is the preferred imaging technique for evaluation of the vessel wall. PURPOSE: To evaluate the intra- and inter-rater reproducibility of carotid wall segmentation on T1W DANTE-SPACE in patients with symptomatic (acute stroke or transient ischemic attack) internal carotid artery (ICA) stenosis. MATERIAL AND METHODS: This prospective study included 25 patients with acute (≤3 months) stroke or transient ischemic attack and 50%-99% stenosis of the ICA. All patients underwent 3.0-T high-resolution carotid MRI. Two radiologists independently performed the manual segmentation of the vessel wall and inner lumen of the bilateral carotid artery on DANTE-SPACE. The intraclass correlation coefficient (ICC), Dice similarity coefficient (DSC), and Hausdorff distance (HD) were calculated. RESULTS: The ICCs for intra-rater reproducibility of carotid wall volume, inner lumen volume, and normalized wall index were 0.965, 0.990, and 0.962, respectively. The ICCs for inter-rater reproducibility of carotid wall volume, inner lumen, and normalized wall index were 0.856, 0.981, and 0.904. DSC and HD for intra- and inter-rater reproducibility of carotid wall segmentation were as follows: 0.873 and 0.809 (DSC); and 0.079 and 0.118 (HD), respectively. For evaluation of reproducibility only in the carotid artery with symptomatic stenosis, the ICCs for intra- and inter-rater reproducibility indicated all perfect agreement. CONCLUSION: T1W DANTE-SPACE is a reproducible sequence for evaluation of the carotid wall using carotid MRI in patients with symptomatic ICA stenosis.
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BACKGROUND: Myelin water imaging (MWI) using MRI has been introduced as a method to quantify the integrity of myelin in vivo. However, the investigation of its potential to probe myelin changes has been limited. PURPOSE: To determine the myelin change using MWI in the corticospinal tract (CST) during the rehabilitation of stroke patients. STUDY TYPE: Longitudinal. POPULATION: A total of 24 stroke patients within 6 months from the onset (64.3 ± 16.1 years, 14 women, 10 men) and 10 healthy volunteers (27.0 ± 2.2 years, 2 women, 8 men). FIELD STRENGTH/SEQUENCE: Three-dimensional multiecho gradient echo sequence and diffusion-weighted echoplanar imaging sequence at 3 T. ASSESSMENT: The changes of myelin water fraction (MWF) and fractional anisotropy (FA) during rehabilitation were analyzed in the CST and other regions using tractography software and region of interest drawings by the radiologist. STATISTICAL TESTS: A paired t-test was performed to investigate the change of MRI metrics during rehabilitation. In addition, an independent two-sample t-test was performed to investigate the effects of different rehabilitation protocols. A P-value <0.05 was considered significant. RESULTS: In the CST, MWF significantly changed from 5.83 ± 0.91% to 6.23 ± 0.97% after rehabilitation while changes of FA (0.442 ± 0.038 to 0.443 ± 0.035) were not significant (P = 0.656). The rate of change in MWF and FA, which were 6.69% and 0.439% respectively, were significantly different. Other regions did not show significant changes (range of MWF change: -3.44% to -1.61%, range of FA change: -1.39% to 0.79%, and range of P-value: 0.144-0.761). Further analysis showed that those with additional robot-assisted rehabilitation had a significantly larger MWF change than those with conventional rehabilitation only (rate of change: 11.2% vs. 3.2%). DATA CONCLUSION: The feasibility of using MWI to monitor myelin content was demonstrated by showing the MWF changes during rehabilitation. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.
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Bainha de Mielina , Acidente Vascular Cerebral , Anisotropia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Acidente Vascular Cerebral/diagnóstico por imagem , ÁguaRESUMO
Resistive random-access memories (RRAMs) based on metal-oxide thin films have been studied extensively for application as synaptic devices in neuromorphic systems. The use of graphene oxide (GO) as a switching layer offers an exciting alternative to other materials such as metal-oxides. We present a newly developed RRAM device fabricated by implementing highly-packed GO layers on a highly doped Si wafer to yield a gradual modulation of the memory as a function of the number of input pulses. By using flow-enabled self-assembly, highly uniform GO thin films can be formed on flat Si wafers in a rapid and simple process. The switching mechanism was explored through proposed scenarios reconstructing the density change of the sp2cluster in the GO layer, resulting in a gradual conductance modulation. We analyzed that the current in a low resistance state could flow by tunneling or hopping via clusters because the distance between the sp2clusters in closely-packed GO layers is short. Finally, through a pattern-recognition simulation with a Modified National Institute of Standards and Technology database, the feasibility of using close-packed GO layers as synapse devices was successfully demonstrated.
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Background and Objectives: This study aimed to evaluate the change of bone height following treatment of human intrabony defects with guided tissue regeneration (GTR) with bone grafting or access flap alone by cone-beam computed tomography (CBCT) scan. Materials and methods: This study was conducted as a retrospective longitudinal study. In this study, a total of 2281 teeth sites were included: the GTR group had 1210 sites, and the Flap group had 1071 sites. In the GTR group, demineralized freeze-dried bone (DFDBA) particles in combination with resorbable collagen membrane were used. No regenerative material was applied to the Flap group. CBCT images were taken twice at baseline and at least 2.5 months postoperatively. Bone heights were measured using software on CBCT images. Results: The bony change between the GTR and Flap groups was significantly different (p = 0.00001). Both males and females in the GTR group had smaller bone loss than in the Flap group. In age groups, significant differences of bony height between the GTR and Flap groups were observed in the subgroups consisting of those 29-45 and 46-53 years old. The non-smoking subjects in the GTR group had higher bone heights than those in the Flap group. In the absence of systemic disease and medicine, bone formation was higher in the GTR group than in the Flap group. In terms of oral position, the #14-17, #34-37, and #44-47 subgroups of the GTR group showed higher levels of bone heights than those of the Flap group. Conclusions. The results of this study indicated that the GTR procedure offers the additional benefit of higher bone heights than the Flap procedure does.
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Perda do Osso Alveolar , Transplante Ósseo , Regeneração Óssea , Tomografia Computadorizada de Feixe Cônico , Feminino , Regeneração Tecidual Guiada Periodontal , Humanos , Estudos Longitudinais , Masculino , Membranas Artificiais , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Background and Objectives: The purpose of this pilot study was to evaluate the clinical outcomes of three different methods for increasing the keratinized mucosa (KM) surrounding dental implants with peri-implantitis. Materials and methods: Twenty implant sites with peri-implantitis were divided into: (1) porcine collagen matrix (CM) group: seven implant sites; (2) apically positioned flap (APF) group: eight implant sites; and (3) free gingival graft (FGG) group: five implant sites. The KM width and clinical parameters (probing pocket depth (PPD) and bleeding on probing (BOP)) were measured at time points: before surgery (T0) and 30 (T1), 60 (T2), 90 (T3), and 180 (T4) days after surgery. Results: Regarding KM width, all the groups had significant differences for increasing horizontal and vertical KM width. The CM and FGG groups had greater KM than the APF group. There was a decrease in PPD in all three groups. APF and FGG showed significant differences in PPD at T1 and T2 compared to T0. Only the FGG group showed a significant difference in PPD at T3 and T4 compared with that at T0. BOP values were also reduced in all the groups at T1-T4 compared to T0. The APF and FGG groups showed a significant decrease in BOP. Conclusions: Three surgical therapies presented favorable results for increasing the KM surrounding implants. Compared with the FGG group, the CM showed similar results in increasing the KM around the dental implants with peri-implantitis.
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Implantes Dentários , Peri-Implantite , Animais , Implantes Dentários/efeitos adversos , Mucosa , Peri-Implantite/cirurgia , Projetos Piloto , Retalhos Cirúrgicos , SuínosRESUMO
OBJECTIVES: To develop a deep learning algorithm for automated detection and localization of intracranial aneurysms on time-of-flight MR angiography and evaluate its diagnostic performance. METHODS: In a retrospective and multicenter study, MR images with aneurysms based on radiological reports were extracted. The examinations were randomly divided into two data sets: training set of 468 examinations and internal test set of 120 examinations. Additionally, 50 examinations without aneurysms were randomly selected and added to the internal test set. External test data set consisted of 56 examinations with intracranial aneurysms and 50 examinations without aneurysms, which were extracted based on radiological reports from a different institution. After manual ground truth segmentation of aneurysms, a deep learning algorithm based on 3D ResNet architecture was established with the training set. Its sensitivity, positive predictive value, and specificity were evaluated in the internal and external test sets. RESULTS: MR images included 551 aneurysms (mean diameter, 4.17 ± 2.49 mm) in the training, 147 aneurysms (mean diameter, 3.98 ± 2.11 mm) in the internal test, 63 aneurysms (mean diameter, 3.23 ± 1.69 mm) in the external test sets. The sensitivity, the positive predictive value, and the specificity were 87.1%, 92.8%, and 92.0% for the internal test set and 85.7%, 91.5%, and 98.0% for the external test set, respectively. CONCLUSION: A deep learning algorithm detected intracranial aneurysms with a high diagnostic performance which was validated using external data set. KEY POINTS: ⢠A deep learning-based algorithm for the automated diagnosis of intracranial aneurysms demonstrated a high sensitivity, positive predictive value, and specificity. ⢠The high diagnostic performance of the algorithm was validated using external test data set from a different institution with a different scanner. ⢠The algorithm might be robust and effective for general use in real clinical settings.
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Algoritmos , Aprendizado Profundo , Aneurisma Intracraniano/diagnóstico , Angiografia por Ressonância Magnética/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos RetrospectivosRESUMO
Considering that the prevalence of cardio-metabolic syndrome in patients with chronic schizophrenia is two or three times higher than the general population, this study aimed to provide patients with schizophrenia using community psychiatric rehabilitation services with therapeutic lifestyle change (TLC) mentoring using a smartphone application and provide inpatients in a psychiatric ward with structured TLC mentoring, to compare improvement in cardio-metabolic factors between the two groups. The home-based community service users using a TLC application were more likely to experience an improvement in their cardio-metabolic factors than the inpatients provided with the structured TLC program.
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Estilo de Vida , Tutoria , Síndrome Metabólica/epidemiologia , Esquizofrenia/reabilitação , Adulto , Índice de Massa Corporal , Feminino , Humanos , Pacientes Internados/estatística & dados numéricos , Lipídeos , Masculino , Síndrome Metabólica/prevenção & controle , Aplicativos Móveis , Prevalência , Smartphone , Circunferência da CinturaRESUMO
PURPOSE: To compare the efficacy and complication rates of radiofrequency ablation (RFA) and repeat surgery in the treatment of locally recurrent thyroid cancers. MATERIALS AND METHODS: A total of 221 patients with locally recurrent thyroid cancers who underwent either RFA (n = 96) or repeat surgery (n = 125) between March 2008 and March 2017 were retrospectively enrolled (range of follow-up, 1-10 years). Each cohort consisted of 70 patients after propensity score adjustment. Patients with more than three recurrent lesions were excluded. The primary and secondary end points were recurrence-free survival and complication rates, respectively. Recurrence-free survival curves were compared via the log-rank test. The complications-voice changes, hypocalcemia, and immediate procedural complications-were compared between the groups. In addition, pretreatment serum thyroglobulin (Tg) levels and those at the last follow-up were also compared between the two groups to examine therapeutic efficacy. RESULTS: After propensity score matching, both groups showed no significant differences in baseline characteristics. The recurrence-free survival rates were comparable between the RFA and surgery groups (p = .2). There were no significant differences in mean serum Tg levels and their mean decrease after treatment between the groups (p = .891 and p = .963, respectively). Immediate procedural complications and voice changes also showed no significant between-group differences (p = .316, p = .084, respectively). Hypocalcemia occurred only in the repeat surgery group (n = 18). Overall complications were significantly more frequent in the repeat surgery group (RFA, n = 7; surgery, n = 27; p < .001). CONCLUSION: RFA may be an effective and safe alternative to repeat surgery in the treatment of a small number of locally recurrent thyroid cancers.
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Ablação por Radiofrequência/efeitos adversos , Ablação por Radiofrequência/métodos , Neoplasias da Glândula Tireoide/radioterapia , Neoplasias da Glândula Tireoide/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pontuação de Propensão , Estudos RetrospectivosRESUMO
In this work, we have implemented nonvolatile resistive random access memory (ReRAM) cells consisting of one transistor (1T) and one resistor (1R) configuration by integrating a high-performance InGaZnO (IGZO) thin-film-transistor (TFT) and an HfO2 resistive switching component on a single substrate for system-on-panel (SoP) technology. ReRAM cells with a 1T-1R configuration can reduce undesired crosstalk caused by leakage current between adjacent memory cells. The a-IGZO TFTs used for 1T-1R integration showed excellent electrical characteristics with a high field-effect mobility of 10.8 cm²/V s, a low subthreshold swing of 226 mV/dec and a large on-off current ratio of 9.2 × 107. The 1T-1R integrated memory cells exhibited BRS behavior, uniform distribution of resistance states and operating voltage, stable DC endurance and reliable data retention characteristics. In addition, we obtained MLC characteristics in a 1T-1R integrated memory cell by controlling the driving current with the gate voltage of a-IGZO TFTs. In multi-level operation, it showed a low operating voltage of 1 V, stable endurance and reliable retention characteristics at 85 °C.
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Gálio , Óxido de Zinco , Índio , ZincoRESUMO
We investigated the effect of post-deposition annealing (PDA) on the gate-bias-stress-induced charge trapping/detrapping phenomenon in amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs). To evaluate device reliability, we used the microwave irradiation (MWI), rapid thermal annealing (RTA), and conventional thermal annealing (CTA) methods for PDA of the TFTs and compared the resulting device performances. Fabricated devices were measured in the dark and under light illumination under positive and negative gate-bias-temperature stress (PBTS and NBTS, respectively). Because microwave energy was transferred directly to the substrate in a short time of 2 min in the MWI device, defects were removed more effectively. The obtained results indicated that the threshold voltage (Vth) shift of the MWI-treated a-IGZO TFT with different temperatures and gate bias stresses in the dark and under light illumination was the smallest and the most reliable. Further, comparisons of the Vth recovery characteristics in the dark and under light illumination indicated that charge detrapping behaviors were enhanced under the latter condition. Furthermore, the average effective energy barrier based on Arrhenius plots was extracted. Therefore, the MWI method is considered promising for fabricating next-generation displays on various substrates.
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In this paper, a novel structure of tunnel field-effect transistors (TFETs) is proposed. The proposed device has an intrinsic polysilicon layer located in the overlap region between the source and the gate, which can increase the tunneling area and overcome the low ON-current drawback of the conventional TFET. The advantages of the proposed device are proven by using technology computeraided design (TCAD) simulation. It exhibits more than 50 higher on-current (ION) of 0.13 µA/µm and lower subthreshold swing (SS) of 53 mV/dec than a conventional planar TFET. In addition, the effect of some device parameters on the device performance has been investigated.
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Mobile technology is a popular intervention mode for patients with schizophrenia because of its accessibility and functionality. We examined patients' willingness to use smartphone apps for lifestyle management and its effect on self-reported lifestyle habits. Five hundred fifty-five inpatients from various mental health institutions participated. Willingness to use smartphone apps was associated with age, education, income, device type, and body mass index. Positive opinions on smartphone app use were significantly associated with willingness to use apps, which was significantly associated with dietary and living habits. Thus, improving willingness to use apps can help patients improve their lifestyle, potentially preventing relapse.
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Doença Crônica/terapia , Estilo de Vida , Aplicativos Móveis , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Esquizofrenia/terapia , Smartphone , Adulto , Comportamento Alimentar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , República da Coreia , Autorrelato , Inquéritos e QuestionáriosRESUMO
BACKGROUND: The liver is a central organ for the metabolism of iron and manganese and the places where those metals are commonly deposited overlap in the brain. PURPOSE/HYPOTHESIS: To elucidate the relationship between pallidal T1 hyperintensity and iron deposition in the deep gray matter of liver cirrhosis patients using quantitative susceptibility mapping (QSM). STUDY TYPE: Retrospective case-control study SUBJECTS: In all, 38 consecutive liver cirrhosis patients who received brain magnetic resonance imaging (MRI) as pretransplant evaluation. FIELD STRENGTH/SEQUENCE: QSM was reconstructed from 3D multi- or single-echo phase images at 3T. T1 -weighted images were used for the assessment of pallidal hyperintensity and pallidal index (PI). ASSESSMENT: Patients were divided into two groups according to the presence of pallidal hyperintensity by consensus of two radiologists. Susceptibility values were acquired for five deep gray matter structures. STATISTICAL TEST: QSM measures were compared between two groups using the t-test. We also calculated Pearson correlations between QSM measures and PI. RESULTS: In all, 26 patients showed pallidal hyperintensity (T1 h group) and 12 did not (T1 n group). The susceptibility of the globus pallidus (GP) in the T1 h group (120.6 ± 38.1 ppb) was significantly lower than that in the T1 n group (150.0 ± 35.2, P = 0.030). The susceptibility of the dentate nucleus (DN) in the T1 h group (88.1 ± 31.0) was significantly lower than that in the T1 n group (125.6 ± 30.6, P = 0.001). Negative correlation between the susceptibility of GP (r = -0.37, P = 0.022) and the PI, and between DN (r = -0.43, P < 0.001) and the PI was found. DATA CONCLUSION: Liver cirrhosis patients with pallidal T1 hyperintensity had lower susceptibility values in the GP and DN than those without it. This suggests a possible interaction between iron and manganese in the brains of liver cirrhosis patients. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1342-1349.
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Encéfalo/diagnóstico por imagem , Globo Pálido/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Ferro/química , Cirrose Hepática/diagnóstico por imagem , Manganês/química , Adulto , Idoso , Mapeamento Encefálico , Estudos de Casos e Controles , Feminino , Humanos , Coeficiente Internacional Normatizado , Cirrose Hepática Alcoólica/diagnóstico por imagem , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
PURPOSE: To explore the feasibility of using correlation-based time-delay (CTD) maps produced from time-resolved MR angiography (TRMRA) to diagnose perfusion abnormalities in patients suspected to have steno-occlusive lesions in the craniocervical arteries. MATERIALS AND METHODS: Twenty-seven patients who were suspected to have steno-occlusive lesions in the craniocervical arteries underwent both TRMRA and brain single-photon emission computed tomography (SPECT). TRMRA was performed on the supra-aortic area after intravenous injection of a 0.03 mmol/kg gadolinium-based contrast agent. Time-to-peak (TTP) maps and CTD maps of the brain were automatically generated from TRMRA data, and their quality was assessed. Detection of perfusion abnormalities was compared between CTD maps and the time-series maximal intensity projection (MIP) images from TRMRA and TTP maps. Correlation coefficients between quantitative changes in SPECT and parametric maps for the abnormal perfusion areas were calculated. RESULTS: The CTD maps were of significantly superior quality than TTP maps (p < 0.01). For perfusion abnormality detection, CTD maps (kappa 0.84, 95% confidence interval [CI] 0.67-1.00) showed better agreement with SPECT than TTP maps (0.66, 0.46-0.85). For perfusion deficit detection, CTD maps showed higher accuracy (85.2%, 95% CI 66.3-95.8) than MIP images (66.7%, 46-83.5), with marginal significance (p = 0.07). In abnormal perfusion areas, correlation coefficients between SPECT and CTD (r = 0.74, 95% CI 0.34-0.91) were higher than those between SPECT and TTP (r = 0.66, 0.20-0.88). CONCLUSION: CTD maps generated from TRMRA were of high quality and offered good diagnostic performance for detecting perfusion abnormalities associated with steno-occlusive arterial lesions in the craniocervical area. KEY POINTS: ⢠Generation of perfusion parametric maps from time-resolved MR angiography is clinically useful. ⢠Correlation-based delay maps can be used to detect perfusion abnormalities associated with steno-occlusive craniocervical arteries. ⢠Estimation of correlation-based delay is robust for low signal-to-noise 4D MR data.
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Arteriopatias Oclusivas/diagnóstico , Artérias Cerebrais/diagnóstico por imagem , Transtornos Cerebrovasculares/diagnóstico , Angiografia por Ressonância Magnética/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Meios de Contraste/administração & dosagem , Estudos de Viabilidade , Feminino , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-IdadeRESUMO
Susceptibility-weighted imaging (SWI) is a method that uses the intrinsic nature of local magnetic fields to enhance image contrast in order to improve the visibility of various susceptibility sources and to facilitate diagnostic interpretation. It is also the precursor to the concept of the use of phase for quantitative susceptibility mapping (QSM). Nowadays, SWI has become a widely used clinical tool to image deoxyhemoglobin in veins, iron deposition in the brain, hemorrhages, microbleeds and calcification. In this article, we review the basics of SWI, including data acquisition, data reconstruction and post-processing. In particular, the source of cusp artifacts in phase images is investigated in detail and an improved multi-channel phase data combination algorithm is provided. In addition, we show a few clinical applications of SWI for the imaging of stroke, traumatic brain injury, carotid vessel wall, siderotic nodules in cirrhotic liver, prostate cancer, prostatic calcification, spinal cord injury and intervertebral disc degeneration. As the clinical applications of SWI continue to expand both in and outside the brain, the improvement of SWI in conjunction with QSM is an important future direction of this technology. Copyright © 2016 John Wiley & Sons, Ltd.
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Encefalopatias/diagnóstico por imagem , Encefalopatias/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Encéfalo/patologia , Encefalopatias/patologia , Imagem de Difusão por Ressonância Magnética/tendências , Previsões , Humanos , Aumento da Imagem/métodos , Imagem Molecular/métodos , Imagem Molecular/tendências , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
A gram-negative, rod shaped bacterium designated as strain H2T was isolated from an artificial pond in Korea. The strain H2T was able to grow aerobically and anaerobically with optimal growth occurring at 30 °C and pH 7.0 under aerobic conditions. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain H2T belonged to the genus Chitinimonas of the family Burkholderiaceae. Phylogenetic similarity calculated from 16S rRNA gene sequences of strain H2T and valid species belongs to the genus Chitinimonas ranged from 93.2â% (for Chitinimonas taiwanensis cfT) to 94.4â% (for Chitinimonas prasina LY03T), and strain H2T formed a tight monophyletic group with them. Predominant fatty acids were C16â:â0 and summed feature 3, which consisted of C16â:â1ω6c and/or C16â:â1ω7c. The major respiratory quinone of the strain H2T was ubiquinone-8, and DNA G+C content was 60.2â%. The polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, unidentified aminolipid, and unidentified phospholipid. The biochemical characteristics that distinguished strain H2T from other Chitinimonas species included positive cystine arylamidase activity and lacked α-chymotrypsin and ß-glucosidase (aesculin hydrolysis) activity. In addition, reciprocal DNA-DNA relatedness between H2T and three Chitinimonas strains ranged from 32.0 to 43.7â%. On the basis of its phylogenetic, chemotaxonomic, and genotypic characteristics, strain H2T represents a novel species of the genus Chitinimonas. Chitinimonas lacunae sp. nov. is proposed with the type strain H2T (=KCTC 52574T=LMG 29894T).
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Burkholderiaceae/classificação , Filogenia , Lagoas/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Burkholderiaceae/genética , Burkholderiaceae/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Ubiquinona/químicaRESUMO
OBJECTIVE: To determine the prevalence of a linear sign within enlarged perivascular space (EPVS) and chronic lacunar infarction (CLI) ≥ 5 mm on T2-weighted imaging (T2WI) and time-of-flight (TOF) magnetic resonance angiography (MRA), and to evaluate the diagnostic value of the linear signs for EPVS over CLI. METHODS: This study included 101 patients with cystic lesions ≥ 5 mm on brain MRI including TOF MRA. After classification of cystic lesions into EPVS or CLI, two readers assessed linear signs on T2WI and TOF MRA. We compared the prevalence and the diagnostic performance of linear signs. RESULTS: Among 46 EPVS and 51 CLI, 84 lesions (86.6%) were in basal ganglia. The prevalence of T2 and TOF linear signs was significantly higher in the EPVS than in the CLI (P < .001). For the diagnosis of EPVS, T2 and TOF linear signs showed high sensitivity (> 80%). TOF linear sign showed significantly higher specificity (100%) and accuracy (92.8% and 90.7%) than T2 linear sign (P < .001). CONCLUSIONS: T2 and TOF linear signs were more frequently observed in EPVS than CLI. They showed high sensitivity in differentiation of them, especially for basal ganglia. TOF sign showed higher specificity and accuracy than T2 sign. KEY POINTS: ⢠Linear sign is a suggestive feature of EPVS. ⢠Time-of-flight magnetic resonance angiography can reveal the lenticulostriate artery within perivascular spaces. ⢠Linear sign helps differentiation of EPVS and CLI, especially in basal ganglia.
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Gânglios da Base/diagnóstico por imagem , Cistos/diagnóstico por imagem , Angiografia por Ressonância Magnética/métodos , Acidente Vascular Cerebral Lacunar/diagnóstico por imagem , Idoso , Gânglios da Base/patologia , Cistos/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Acidente Vascular Cerebral Lacunar/patologiaRESUMO
PURPOSE: The purposes of the present study are to assess whether different characteristics of oligodendrogliomas and astrocytic tumors are visible on MR imaging and to determine the added value of perfusion imaging in conventional MR imaging when differentiating oligodendrogliomas from astrocytic tumors. METHODS: We retrospectively studied 22 oligodendroglioma and 54 astrocytic tumor patients, including glioblastoma multiforme (GBM). The morphological tumor characteristics were evaluated using MR imaging. The rCBV, K trans, and V e values were recorded. All imaging and clinical values were compared. The ability to discriminate between the two entities was evaluated using receiver operating characteristic curve analyses. Separate comparison analysis between oligodendroglioma and astrocytic tumors excluding GBM was also performed. RESULTS: The presence of calcification, higher cortex involvement ratio, and lower V e value were more representative of oligodendrogliomas than astrocytic tumors (P = <0.001, 0.038, and <0.001, respectively). The area under the curve (AUC) value of a combination of calcification and cortex involvement ratio was 0.796. The combination of all three parameters, including V e, further increased the diagnostic performance (AUC = 0.881). Comparison test of the two AUC areas revealed significant difference (P = 0.0474). The presence of calcification and higher cortex involvement ratio were the only findings suggestive of oligodendrogliomas than astrocytic tumors with exclusion of GBMs (P = 0.014 and <0.001, respectively). CONCLUSION: Cortex involvement ratio and the presence of calcification with V e values were diagnostically accurate in identifying oligodendrogliomas. The V e value calculated from dynamic contrast-enhanced MR imaging could be a supportive tool for differentiating between oligodendrogliomas and astrocytic tumors including GBMs.
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Astrocitoma/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Glioblastoma/diagnóstico por imagem , Angiografia por Ressonância Magnética , Oligodendroglioma/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Meios de Contraste , Diagnóstico Diferencial , Feminino , Glioblastoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Oligodendroglioma/patologia , Estudos RetrospectivosRESUMO
BACKGROUND: Pulse wave velocity is a marker of arterial stiffness and a surrogate marker of vascular damage. Autonomic abnormalities associated with blood pressure are relatively commonly observed in patients with Parkinson's disease (PD). OBJECTIVE: The purpose of this study was to compare arterial stiffness between patients with PD and controls and investigate the associations between cardiovascular autonomic dysfunction and pulse wave velocity in PD. METHODS: One hundred twenty-five PD patients without diabetes mellitus were enrolled into this study, along with 22 age-matched controls. Orthostatic vital signs and ambulatory 24-hour blood pressure monitoring values were recorded. Pulse wave velocity was used to evaluate arterial stiffness. RESULTS: In PD, greater arterial stiffness was associated with orthostatic hypotension, supine hypertension, nocturnal hypertension, and nondipping. Dopaminergic treatment did not influence cardiovascular autonomic dysfunction or arterial stiffness. Although pulse wave velocity was mildly increased in patients with PD compared to controls, the arterial stiffness in PD patients without autonomic failure was similar to that in normal controls. Stiffer arteries were found only in patients with PD and autonomic failure. CONCLUSION: These findings suggest that cardiovascular autonomic dysfunction is associated with arterial stiffness in PD. PD itself does not affect arterial stiffness, whereas autonomic blood pressure disturbances influence alterations in arterial stiffness and architectural changes in the arteries of PD patients.
Assuntos
Doenças do Sistema Nervoso Autônomo/complicações , Sistema Cardiovascular/fisiopatologia , Doença de Parkinson/complicações , Rigidez Vascular , Idoso , Sistema Nervoso Autônomo/fisiopatologia , Doenças do Sistema Nervoso Autônomo/diagnóstico , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Pressão Sanguínea , Feminino , Humanos , Hipertensão/etiologia , Hipotensão Ortostática/etiologia , Hipotensão Ortostática/fisiopatologia , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/fisiopatologia , Análise de Onda de Pulso , Decúbito DorsalRESUMO
BACKGROUND: Iron deposition of basal ganglia in Parkinson's disease (PD) can be measured using susceptibility weighted images (SWI) on magnetic resonance imaging (MRI). Fluoropropyl carbomethoxy-3b-4-iodophenyltropane (F18 FP-CIT) positron emission tomography (PET) has been used to differentiate Parkinsonism. PURPOSE: To compare SWI phase values in Parkinsonian syndrome and age-matched control and to correlate them with F18 FP-CIT PET. MATERIAL AND METHODS: Retrospectively, patients with Parkinsonian movement disorder (n = 62) and age-matched control (n = 16) were enrolled. Mean phase values on SWI were measured by region of interest (ROI) in putamens and caudate heads. Mean standardized uptake value (SUV) on F18 FP-CIT were measured in the same ROIs of PD (n = 40) and other forms of Parkinsonism (n = 22). A statistical analysis was performed to compare the phase values and SUVs and to correlate them between groups. RESULTS: The putaminal mean phase values were higher in Parkinsonism than in the control (P ≤ 0.001). There was no difference of phase value in caudate head among the groups. Also, the mean phase value of putamen between PD and other forms of Parkinsonism was not different. Mean SUV of F18 FP-CIT in the putamen was lower in PD than other forms of Parkinsonism (P ≤ 0.014). However, there was no significant correlation between phase values and mean SUV (P > 0.05). CONCLUSION: The putaminal phase value was higher than in Parkinsonian syndrome than in the age-matched controls. F18 FP-CIT PET/CT showed different tracer activity between PD and other forms of Parkinsonism. However, no correlation between phase and SUV values was discovered.