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1.
Artigo em Inglês | MEDLINE | ID: mdl-33878750

RESUMO

A carrier doping by a hydrogen substitution in LaFeAsO$_{1-x}$H$_x$ is known to cause two superconducting (SC) domes with the magnetic order at both end sides of the doping. In contrast, SmFeAsO$_{1-x}$H$_x$ has a similar phase diagram but shows single SC dome. Here, we investigated the electronic and crystal structures for iron oxynictide $Ln$FeAsO$_{1-x}$H$_x$ ($Ln=$ La, Sm) with the range of $x$ = 0--0.5 by using x-ray absorption spectroscopy, x-ray emission spectroscopy, and x-ray diffraction. For both compounds, we observed that the pre-edge peaks of x-ray absorption spectra near the Fe-$K$ edge were reduced in intensity on doping. The character arises from the weaker As-Fe hybridization with the longer As-Fe distance in the higher doped region. We can reproduce the spectra near the Fe-$K$ edge according to the Anderson impurity model with realistic valence structures using the local-density approximation (LDA) plus dynamical mean-field theory (DMFT). For $Ln=$ Sm, the integrated-absolute difference (IAD) analysis from x-ray Fe-$K¥beta$ emission spectra increases significantly. This is attributed to the enhancement of magnetic moment of Fe $3d$ electrons stemming from the localized picture in the higher doped region. A theoretical simulation implementing the self-consistent vertex-correction method reveals that the single dome superconducting phase for $Ln=$ Sm arises from a better nesting condition in comparison with $Ln=$ La.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33890871

RESUMO

We examine electronic and crystal structures of iron-based superconductors $Ln$FeAsO$_{1-x}$H$_x$ ($Ln=$ La, Sm) under pressure by means of x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES), and x-ray diffraction. In LaFeAsO the pre-edge peak on high-resolution XAS at the Fe-$K$ absorption edge gains in intensity on the application of pressure up to 5.7 GPa and it saturates in the higher pressure region. We found integrated-absolute difference values on XES for $Ln$ = La, corresponding to a spin state, decline on the application of pressure, and then it is minimized when the $T_{¥rm c}$ approaches the maximum at around 5~GPa. In contrast, such the optimum value was not detected for $Ln$ = Sm. We reveal that the superconductivity is closely related to the lower spin state for $Ln$ = La unlike Sm case. We observed that As height from the Fe basal plane and As-Fe-As angle on the FeAs$_4$ tetrahedron for $Ln$ = La deviate from the optimum values of the regular tetrahedron in superconducting (SC) phase, which has been a widely accepted structural guide to SC thus far. In contrast, the structural parameters were held near the optimum values up to $¥sim$15 GPa for $Ln$ = Sm.

3.
In Vivo ; 35(2): 1205-1209, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33622922

RESUMO

BACKGROUND/AIM: In 2020, the percentages were removed from the World Health Organization's criteria for mixed carcinoma. The aim was to examine the clinical significance of an area of serous carcinoma (SC) <5%. PATIENTS AND METHODS: Our study included 236 patients with the 2009 International Federation of Obstetrics and Gynecology (FIGO) stage IA grade 1 endometrioid carcinoma (EG1) from multiple hospitals. EG1 patients with an area of SC <5% and those with pure-type EG1 were retrospectively compared. RESULTS: In the multivariate analysis for recurrence, an area of SC <5% was an independent risk factor [hazard ratio (HR)=101.51, p<0.01]. In the multivariate analysis for progression-free survival, an area of SC <5% was identified as a negative prognostic factor (HR=62.43, p<0.01). CONCLUSION: EG1 with an area of SC <5% may be more aggressive than pure-type EG1 at FIGO stage IA.

4.
Artigo em Japonês | MEDLINE | ID: mdl-33473077

RESUMO

BACKGROUND: 18F-florbetapir is an amyloid ß (Aß) -targeted 18F-labeled positron emission tomography (PET) tracer for the clinical diagnosis of Alzheimer's disease. The standardized uptake value ratio (SUVR) serves as a tool with which to differentially diagnose. The present study aimed to cross-validate and compare SUVR derived from Amygo neuro and MIMneuro software. METHODS: We injected 40 individuals with 18F-florbetapir and then acquired PET images from 50 to 60 minutes later. All images were separately normalized to the standard 18F-florbetapir PET template using Amygo neuro and MIMneuro. Volumes of interest (VOIs) were automatically placed on six target regions each in Amygo neuro and MIMneuro. The composite SUVR (cSUVR) and regional SUVR (rSUVR) were calculated from mean values measured in VOI. A cSUVR of>1.10 was defined as representing Aß positivity. Correlation coefficients were calculated in the two types of software. RESULTS: A cSUVR>1.10 was determined by Amygo neuro and MIMneuro in 15 of the 40 individuals. The rSUVR in the posterior cingulate, parietal lobe, precuneus, and temporal lobe significantly differed between Amygo neuro and MIMneuro, whereas the cSUVR did not. The SUVR calculated by the two types of software closely correlated to each other (R=0.89-0.96, P<0.05). CONCLUSIONS: The cSUVR was not different between Amygo neuro and MIMneuro. We suggest that Amygo neuro is comparable to MIMneuro in quantitative analysis using SUVR for 18F-florbetapir imaging, thus facilitating the use of standardized quantitative approaches to amyloid PET imaging.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/metabolismo , Compostos de Anilina , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Etilenoglicóis , Humanos , Tomografia por Emissão de Pósitrons , Software
5.
ACS Chem Neurosci ; 12(4): 746-755, 2021 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-33502174

RESUMO

Histone deacetylase 6 (HDAC6), an enzyme involved in protein degradation, exhibits several unique properties, such as cytoplasmic localization and ubiquitin binding. HDAC6 has emerged as an interesting therapeutic target in the treatment of neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Techniques enabling noninvasive HDAC6 imaging in the brain could enhance understanding of its pathologic role, but development of brain-penetrating radioligands for HDACs imaging by positron emission tomography (PET) remains challenging. Here, we report the synthesis and evaluation of an 18F-labeled tetrahydroquinoline derivative, [18F]2, based on the HDAC6 selective inhibitor SW-100 as a brain HDAC6 imaging radioligand. [18F]2 was synthesized via copper-mediated radiofluorination from an arylboronic precursor, followed by removal of the catalyst by solid-phase extraction and then hydroxamic acid formation. [18F]2 demonstrated good penetration and moderate stability in the mouse brain. In mouse plasma, however, [18F]2 was rapidly metabolized to a corresponding carboxylic acid form. Blocking studies in mice with unlabeled compound 2 and HDAC6 selective inhibitors, including tubastatin A and ACY-775, demonstrated that the HDAC6 inhibitors displaced over 80% of [18F]2 taken up in the brain, indicating selective binding of [18F]2. These results suggest that [18F]2 is a potentially useful PET radioligand for brain HDAC6 imaging.

6.
Clin Nucl Med ; 46(1): e31-e33, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32657879

RESUMO

Three patients with neurological disorders (cerebral infarction, progressive multifocal leukoencephalopathy, and multiple sclerosis) underwent F-THK5351 and C-L-deprenyl PET on the same day to visualize lesions undergoing astrogliosis by measuring MAO-B activity. BPND map and SUV image with F-THK5351 as well as Ki map, Ki/K1 map and SUV image with C-L-deprenyl were created. F-THK5351 BPND maps and SUV images clearly identified the lesions undergoing astrogliosis. C-L-deprenyl Ki/K1 maps were close to F-THK5351 images, but very noisy. Ki maps and SUV images were likely affected by the effect of blood flow. Hence, F-THK5351 is superior to C-L-deprenyl for visualizing lesions undergoing astrogliosis.


Assuntos
Aminopiridinas/metabolismo , Radioisótopos de Carbono , Gliose/diagnóstico por imagem , Monoaminoxidase/metabolismo , Doenças do Sistema Nervoso/complicações , Tomografia por Emissão de Pósitrons , Quinolinas/metabolismo , Selegilina/metabolismo , Feminino , Gliose/complicações , Gliose/metabolismo , Humanos , Ligantes , Masculino
7.
EJNMMI Phys ; 7(1): 70, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33226451

RESUMO

BACKGROUND: Silicon photomultiplier-positron emission tomography (SiPM-PET) has better sensitivity, spatial resolution, and timing resolution than photomultiplier tube (PMT)-PET. The present study aimed to clarify the advantages of SiPM-PET in 18F-fluoro-2-deoxy-D-glucose ([18F]FDG) brain imaging in a head-to-head comparison with PMT-PET in phantom and clinical studies. METHODS: Contrast was calculated from images acquired from a Hoffman 3D brain phantom, and image noise and uniformity were calculated from images acquired from a pool phantom using SiPM- and PMT-PET. Sequential PMT-PET and SiPM-PET [18F]FDG images were acquired over a period of 10 min from 22 controls and 10 patients. All images were separately normalized to a standard [18F]FDG PET template, then the mean standardized uptake values (SUVmean) and Z-score were calculated using MIMneuro and CortexID Suite, respectively. RESULTS: Image contrast, image noise, and uniformity in SiPM-PET changed 19.2, 3.5, and - 40.0% from PMT-PET, respectively. These physical indices of both PET scanners satisfied the criteria for acceptable image quality published by the Japanese Society of Nuclear Medicine of contrast > 55%, CV ≤ 15%, and SD ≤ 0.0249, respectively. Contrast was 70.0% for SiPM-PET without TOF and 59.5% for PMT-PET without TOF. The TOF improved contrast by 3.5% in SiPM-PET. The SUVmean using SiPM-PET was significantly higher than PMT-PET and did not correlate with a time delay. Z-scores were also significantly higher in images acquired from SiPM-PET (except for the bilateral posterior cingulate) than PMT-PET because the peak signal that was extracted by the calculation of Z-score in CortexID Suite was increased. The hypometabolic area in statistical maps was reduced and localized using SiPM-PET. The trend was independent of whether the images were derived from controls or patients. CONCLUSIONS: The improved spatial resolution and sensitivity of SiPM-PET contributed to better image contrast and uniformity in brain [18F]FDG images. The SiPM-PET offers better quality and more accurate quantitation of brain PET images. The SUVmean and Z-scores were higher in SiPM-PET than PMT-PET due to improved PVE. [18F]FDG images acquired using SiPM-PET will help to improve diagnostic outcomes based on statistical image analysis because SiPM-PET would localize the distribution of glucose metabolism on Z-score maps.

9.
Aging (Albany NY) ; 12(19): 19701-19710, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-33024054

RESUMO

Voxel-based morphometry (VBM) analysis of nuclear Magnetic Resonance Imaging (MRI) data allows the identification of medial temporal lobe (MTL) atrophy and is widely used to assist the diagnosis of Alzheimer's disease (AD). However, its reliability in the clinical environment has not yet been confirmed. To determine the credibility of VBM, amyloid positron emission tomography (PET) and VBM studies were compared retrospectively. Patients who underwent Pittsburgh Compound B (PiB) PET were retrospectively recruited. Ninety-seven patients were found to be amyloid negative and 116 were amyloid positive. MTL atrophy in the PiB positive group, as quantified by thin sliced 3D MRI and VBM software, was significantly more severe (p =0.0039) than in the PiB negative group. However, data histogram showed a vast overlap between the two groups. The area under the ROC curve (AUC) was 0.646. MMSE scores of patients in the amyloid negative and positive groups were also significantly different (p = 0.0028), and the AUC was 0.672. Thus, MTL atrophy could not reliably differentiate between amyloid positive and negative patients in a clinical setting, possibly due to the wide array of dementia-type diseases that exist other than AD.

10.
Clin Case Rep ; 8(9): 1651-1658, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32983470

RESUMO

Thigh pain after hip arthroplasty is multifactorial; uncovering its etiology is paramount for optimal treatment. This is the first case where 18F-sodium fluoride positron emission tomography substantially helped in diagnosing the post-hip arthroplasty persistent thigh pain and appropriate treatment selection. This imaging modality warrants further study and more widespread application.

11.
EJNMMI Phys ; 7(1): 56, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32915344

RESUMO

BACKGROUND: The Bayesian penalized likelihood (BPL) algorithm Q.Clear (GE Healthcare) allows fully convergent iterative reconstruction that results in better image quality and quantitative accuracy, while limiting image noise. The present study aimed to optimize BPL reconstruction parameters for 18F-NaF PET/CT images and to determine the feasibility of 18F-NaF PET/CT image acquisition over shorter durations in clinical practice. METHODS: A custom-designed thoracic spine phantom consisting of several inserts, soft tissue, normal spine, and metastatic bone tumor, was scanned using a Discovery MI PET/CT scanner (GE Healthcare). The phantom allows optional adjustment of activity distribution, tumor size, and attenuation. We reconstructed PET images using OSEM + PSF + TOF (2 iterations, 17 subsets, and a 4-mm Gaussian filter), BPL + TOF (ß = 200 to 700), and scan durations of 30-120 s. Signal-to-noise ratios (SNR), contrast, and coefficients of variance (CV) as image quality indicators were calculated, whereas the quantitative measures were recovery coefficients (RC) and RC linearity over a range of activity. We retrospectively analyzed images from five persons without bone metastases (male, n = 1; female, n = 4), then standardized uptake values (SUV), CV, and SNR at the 4th, 5th, and 6th thoracic vertebra were calculated in BPL + TOF (ß = 400) images. RESULTS: The optimal reconstruction parameter of the BPL was ß = 400 when images were acquired at 120 s/bed. At 90 s/bed, the BPL with a ß value of 400 yielded 24% and 18% higher SNR and contrast, respectively, than OSEM (2 iterations; 120 s acquisitions). The BPL was superior to OSEM in terms of RC and the RC linearity over a range of activity, regardless of scan duration. The SUVmax were lower in BPL, than in OSEM. The CV and vertebral SNR in BPL were superior to those in OSEM. CONCLUSIONS: The optimal reconstruction parameters of 18F-NaF PET/CT images acquired over different durations were determined. The BPL can reduce PET acquisition to 90 s/bed in 18F-NaF PET/CT imaging. Our results suggest that BPL (ß = 400) on SiPM-based TOF PET/CT scanner maintained high image quality and quantitative accuracy even for shorter acquisition durations.

12.
J Occup Health ; 62(1): e12159, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32845553

RESUMO

OBJECTIVE: To examine whether the self-monitoring interventions of a mobile health app reduce sedentary behavior in the short and long terms. METHOD: We designed a double-blind randomized control trial. Participants were selected from among the staff of a medical institution and registrants of an online research firm. Forty-nine participants were randomly assigned to either a control group (n = 25) or an intervention group (n = 24). The control group was given only the latest information about sedentary behavior, and the intervention was provided real-time feedback for self-monitoring in addition to the information. These interventions provided for 5 weeks (to measure the short-term effect) and 13 weeks (to measure the long-term effect) via the smartphone app. Measurements were as follows: subjective total sedentary time (SST), objective total sedentary time (OST), mean sedentary bout duration (MSB), and the number of sedentary breaks (SB). Only SST was measured by self-report based on the standardized International Physical Activity Questionnaire and others were measured with the smartphone. RESULTS: No significant results were observed in the short term. In the long term, while no significant results were also observed in objective sedentary behavior (OST, MSB, SB), the significant differences were observed in subjective sedentary behavior (SST, ßint  - ßctrl between baseline and 9/13 weeks; 1.73 and 1.50 h/d, respectively). CONCLUSIONS: Real-time feedback for self-monitoring with smartphone did not significantly affect objective sedentary behavior. However, providing only information about sedentary behavior to users with smartphones may make misperception on the amount of their subjective sedentary behavior.

13.
Ann Nucl Med ; 34(10): 762-771, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32623569

RESUMO

OBJECTIVE: Many advances in PET/CT technology can potentially improve image quality and the ability to detect small lesions. A new digital TOF-PET/CT scanner based on silicon photomultipliers (SiPM) integrated with a Bayesian penalized likelihood (BPL) PET reconstruction algorithm (Q.Clear; GE Healthcare) has been introduced into clinical practice. The present study aimed to quantify the ability of a digital TOF-PET/CT scanner combined with BPL reconstruction to detect small lesions, and to determine the optimal penalization factor (ß) in BPL to accurately detect such lesions. METHODS: All PET data were acquired from a NEMA body phantom using a Discovery MI (DMI) PET/CT system (GE Healthcare). The phantom included six spheres with diameters of 4, 5, 6, 8, 10, and 13 mm, and contained a background activity level of 5.3 kBq/mL, with target-to-background ratios (TBR) of 4:1 and 8:1. Images were reconstructed using a baseline OSEM algorithm, with OSEM + PSF, OSEM + TOF, OSEM + PSF + TOF, and BPL + PSF + TOF (ß: 50-400). The matrix size was 192 × 192 and 384 × 384. Data acquired in 100-min list mode were re-binned into acquisition times ranging from 2 to 100 min. The quantitative accuracy and detectability of small hot spheres were evaluated by physical assessment of a recovery coefficient (RC) and a detectability index (DI), as well as visual assessment of PET images at each acquisition time. RESULTS: The RC and DI of sub-centimeter spheres were improved, because the digital TOF-PET/CT scanner has a larger TOF performance gain due to better timing resolution. The RC and DI were higher with BPL in sub-centimeter spheres, than with other OSEM-based types of reconstruction. The BPL for an 8-mm sphere overestimated uptake due to edge artifact overshoot induced by PSF modeling. The variability of RC and DI for acquisition times and TBR differed considerably according to ß values. The RC for ~ 8-mm spheres were > 1 at ß values between 50 and 100, but were close to 1 at ß value of 200. The visual scores for ß = 200 in BPL were maximal, whereas those for spheres that were ≥ 6 mm exceeded the criterion of 3. CONCLUSION: The BPL in the digital TOF-PET/CT scanner improved the quantitation and detectability of sub-centimeter spheres compared with OSEM-based reconstruction. Optimization of the ß value in BPL might allow the detection of lesions ≤ 6 mm, although detectability depended on the TBR of lesions. A ß value of 200 seemed optimal for detecting sub-centimeter lesions.

14.
BMC Med Imaging ; 20(1): 81, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32664871

RESUMO

BACKGROUND: 18F-THK5351 was recently shown to bind to monoamine oxidase B (MAO-B) with high affinity. MAO-B is highly concentrated in astrocytes and increases during astrogliosis. Therefore, 18F-THK5351 accumulates in lesions undergoing astrogliosis. Cerebral infarction causes astrogliosis, which may be beneficial for repairing and regenerating injured cells and tissues in the lesions. Therefore, monitoring the degree of astrogliosis and stroke symptoms is essential for understanding the roles of astrogliosis in cerebral infarction. CASE PRESENTATION: A 72-year-old man, complaining of total loss of sensation in the left index finger, was diagnosed with acute cerebral infarction, and underwent 18F-THK5351 positron emission tomography (PET) on two occasions after the stroke. The first PET scan performed on day 27 revealed intense uptake in the infarct lesion located around the right precentral and postcentral gyri. However, the second PET scan on day 391 showed that the uptake had diminished significantly. The sensory deficit in the left index finger had improved by 30 and 70% at the times of the first and second PET scans, respectively. CONCLUSIONS: 18F-THK5351 uptake in the infarct lesion evidently changed between days 27 and 391, along with improved sensory deficit in the left index finger. Astrocytes reportedly play a role in restoring neuronal integrity. Therefore, the temporal course of astrogliosis may have been related to improving stroke symptoms in this patient, suggesting that the degree of astrogliosis in the infarct lesion may aid in assessing the prognosis in stroke patients.

15.
Acta Neurochir (Wien) ; 162(10): 2513-2517, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32617679

RESUMO

We report the case of a patient with hypothalamic hamartoma (HH) who was successfully treated with magnetic resonance-guided focused ultrasound (MRgFUS) for ablation as a disconnection surgery. A 26-year-old man with gelastic epilepsy had been diagnosed with HH at 3 years of age, and antiepileptic drugs were administered due to worsening episodes. Magnetic resonance imaging showed a sessile parahypothalamic hamartoma and MRgFUS ablation was performed, creating an oval-shaped lesion at the boundary area of the HH. Dramatic improvements in seizure symptoms were noted, and he was seizure-free on decreased antiepileptic drugs without any adverse events over the 1-year follow-up period.

16.
Ann Nucl Med ; 34(7): 467-475, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32378149

RESUMO

PURPOSE: To investigate the characteristics of patients with moyamoya disease (MMD) who show improvement in their cognitive decline after bypass surgery by analyzing the hemodynamic and metabolic parameters of 15O-gas positron emission tomography (PET). MATERIALS AND METHODS: We retrospectively analyzed adult patients with MMD who were evaluated with PET and cognitive tests before and approximately one year after indirect bypass surgery. The PET parameters of the left Rolandic area were compared between patients who did and did not show improvement in their cognitive decline. RESULTS: Of the 19 patients analyzed, fourteen (74%) showed improvement in either the verbal or performance intelligence quotient (VIQ or PIQ). Three out of four patients with perioperative infarction experienced significant cognitive decline. The preoperative oxygen extraction fraction (OEF) was significantly higher in patients who showed improvement in their cognitive decline in terms of the PIQ than in those patients who did not (P = 0.03). The postoperative increase in the cerebral metabolic rate of oxygen (CMRO2) was significantly higher in patients who showed improvement in their cognitive decline in terms of the VIQ than in those who did not (P = 0.02). CONCLUSION: Adult patients with MMD might show improvement in their cognitive decline after successful indirect bypass surgery if they have a severely increased regional OEF before the surgery and an increased regional CMRO2 after the surgery. CLINICAL TRIAL REGISTRATION: URL: https://www.umin.ac.jp/ctr/. Unique identifier: UMIN000027949.

17.
Alzheimers Dement (N Y) ; 6(1): e12007, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32211510

RESUMO

Introduction: Possession of the apolipoprotein E (APO E) ε4 allele advances amyloid ß (Aß) deposition and symptomatic onset of Alzheimer's disease (AD), whereas its effect on the rate of cognitive decline remained controversial. We examined the effects of APOE ε4 allele on cognition in biomarker-confirmed late mild cognitive impairment (LMCI) and mild AD subjects in the Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI) and North American ADNI (NA-ADNI). Methods: The "early AD" (ie, combined LMCI and mild AD) cohort of 649 subjects from J-ADNI and NA-ADNI were selected based on positivity of Aß confirmed by amyloid positron emission tomography (PET) or cerebrospinal fluid testing. The rates of cognitive decline in the Mini Mental State Examination (MMSE), the Clinical Dementia Rating Sum of Boxes (CDR-SB), and the Alzheimer's Disease Assessment Scale-cognitive subscale 13 (ADAS-Cog) from baseline were examined using mixed-effects model. The effect of ε4 on time to conversion to dementia was also analyzed in LMCI using the Kaplan-Meier estimator and log-rank test. Results: The rates of cognitive decline were not significantly different between ε4 carriers and ε4 non-carriers in the total early AD cohort, which were affected neither by region nor by the number of ε4 alleles. In LMCI, ε4 carriers showed almost the same progression rates as ε4 non-carriers, except for a significantly faster decline in MMSE (P = .0282). Time to conversion to demenita was not significantly different between ε4 carriers and ε4 non-carriers. In ε4-positive mild AD, the rates of decline in MMSE (P = .003) and CDR-SB (P = .0071) were slower than those in ε4 non-carriers. DISCUSSION: The APOE ε4 allele had little effect on the rates of cognitive decline in the overall biomarker-confirmed early AD, regardless of region and number of ε4 alleles, with a slight variability in different clinical stages, the ε4 allele being slightly accelerative in LMCI, while decelerative in mild AD.

18.
Clin Nucl Med ; 45(4): e185-e189, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32049727

RESUMO

BACKGROUND: Brain F-FDG uptake reportedly starts to decline more than 10 years before the onset of cognitive decline in dominantly inherited Alzheimer disease (AD). We compared longitudinal F-FDG images in sporadic AD to aging data from a large sample size to expand the current knowledge of F-FDG reduction for AD progression. METHODS: Participants comprised 2 individuals (subjects A and B at ages 65 and 68 years, respectively) and 107 control subjects (67.9 [SD, 4.9] years). Subject A underwent F-FDG PET a total of 8 times over 9 years from the preclinical to early dementia stages. Subject B underwent F-FDG PET a total of 11 times over 12 years from the preclinical to mild cognitive impairment stages. Control subjects underwent F-FDG PET twice over a mean follow-up period of 7.8 years. After placing the volume of interest on the AD-related hypometabolic regions, the longitudinal F-FDG images were compared among the subjects and control subjects. RESULTS: For the control group, the rate of F-FDG reduction was 2.2% per decade (ie, aging effects). The rates of F-FDG reduction were 9.41% over 9 years and 9.07% over 12 years in subjects A and B, respectively. We estimated that F-FDG uptake started to decrease 4 and 2 years before indications of memory loss in subjects A and B, respectively. CONCLUSIONS: The present study suggests that the time between the beginning of F-FDG reduction and the onset of cognitive decline may be shorter in elderly individuals with AD compared with the recently estimated period in dominantly inherited AD.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Progressão da Doença , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos
19.
Aging Clin Exp Res ; 32(11): 2349-2355, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31953630

RESUMO

BACKGROUND: Influence of cognitive intervention programs on brain activity has not been enough explored. AIMS: The aims of the present study were to clarify changes in brain activity from a cognitive intervention program utilizing the board game "Go" and to examine the relationship between brain activity and the acquisition of Go skills. METHODS: Eighteen community-dwelling older adults were randomly assigned either to an intervention group (IG), in which members attended 12 Go lessons either in groups or individually using tablet computers, or a control group (CG), in which members attended health education lectures unrelated to Go. Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography (PET), cognitive assessments, and Go tests were performed before and after the intervention. RESULTS: The results showed different patterns of regional FDG uptake in both groups: regional cerebral glucose metabolism was significantly increased in the left middle temporal gyrus (MTG) and bilateral putamen (p < 0.01; cluster level) in the IG, and in the left superior frontal gyrus in the CG, (p < 0.01; cluster level). Furthermore, Go test scores were significantly improved in the IG (p < 0.05), and a significant association was observed between changes in Go test scores and glucose metabolism in the left MTG (p < 0.05). CONCLUSIONS AND DISCUSSION: This study indicates that a cognitive intervention program using Go may enhance brain activity. Further studies with larger populations and longer observation periods are needed to clarify the neural mechanisms underlying our Go intervention program.

20.
J Alzheimers Dis ; 73(1): 197-207, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31771066

RESUMO

BACKGROUND: Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) are often misdiagnosed with each other because of similar symptoms including progressive memory loss. The metabolic network topology that describes inter-regional metabolic connections can be generated using fluorodeoxyglucose positron emission tomography (FDG-PET) data with the graph-theoretical method. We hypothesized that different metabolic connectivity underlies the symptoms of AD patients, DLB patients, and cognitively normal (CN) individuals. OBJECTIVE: This study aimed to generate metabolic connectivity using FDG-PET data and assess the network topology to differentiate AD patients, DLB patients, and CN individuals. METHODS: This study included 45 AD patients, 18 DLB patients, and 142 CN controls. We analyzed FDG-PET data using the graph-theoretical method and generated the network topology in AD patients, DLB patients, and CN individuals. We statistically assessed the topology with global and nodal parameters. RESULTS: The whole metabolic network was preserved in CN; however, diffusely decreased connection was found in AD and partially but more deeply decreased connection was observed in DLB. The metabolic topology revealed that the right posterior cingulate and the left transverse temporal gyrus were significantly different between AD and DLB. CONCLUSION: The present findings indicate that metabolic connectivity decreased in both AD and DLB, compared with CN. DLB was characterized restricted but deeper stereotyped network disruption compared with AD. The right posterior cingulate and the left transverse temporal gyrus are significant regions in the metabolic connectivity for differentiating AD from DLB.

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