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1.
Oncology ; 101(5): 343-348, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36889294

RESUMO

BACKGROUND: Proteasome inhibitors (PIs) are standard treatments for multiple myeloma (MM). The risk of cardiac adverse events (CAEs) with PIs has been documented with bortezomib and carfilzomib; however, only a few studies have been reported on ixazomib. Furthermore, the effects of concomitant medications including dexamethasone and lenalidomide remain unclear. OBJECTIVES: This study aimed to determine the safety signals of adverse events related to CAEs, the effect of concomitant medications, the time to the occurrence of CAEs, and the incidence of fatal clinical outcomes after the occurrence of CAEs for three PIs using the US Pharmacovigilance database. METHODS: We examined 1,567,240 cases of 231 drugs registered as anticancer drugs in the US Food and Drug Administration Adverse Event Reporting System (FAERS) database from January 1997 to March 2021. We compared the odds of developing CAEs between patients who received PIs and those who received non-PI anticancer drugs. RESULTS: Bortezomib treatment resulted in significantly higher reporting odds ratios (RORs) for cardiac failure, cardiac failure congestive, and atrial fibrillation. Carfilzomib treatment resulted in significantly higher RORs for cardiac failure, congestive cardiac failure, atrial fibrillation, and QT prolonged. However, no adverse event CAE signals were observed with ixazomib treatment. A signal was detected for the safety of cardiac failure with bortezomib or carfilzomib, regardless of the presence or absence of concomitant medications. Safety signals for cardiac failure congestive with bortezomib and for cardiac failure congestive, atrial fibrillation, and QT prolonged with carfilzomib were observed only with dexamethasone combination therapy. Co-administration of lenalidomide and its derivatives did not affect the safety of bortezomib and carfilzomib. CONCLUSION: We identified CAE safety signals for bortezomib and carfilzomib exposure when compared with 231 other anticancer agents. The safety signal for developing cardiac failure for both the drugs did not differ between patients with and without concomitantly administered medications.


Assuntos
Antineoplásicos , Fibrilação Atrial , Insuficiência Cardíaca , Mieloma Múltiplo , Humanos , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Proteassoma/efeitos adversos , Bortezomib/efeitos adversos , Lenalidomida/uso terapêutico , Fibrilação Atrial/induzido quimicamente , Fibrilação Atrial/tratamento farmacológico , Antineoplásicos/efeitos adversos , Dexametasona/efeitos adversos , Insuficiência Cardíaca/induzido quimicamente , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
2.
Eur Radiol ; 33(5): 3253-3265, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36973431

RESUMO

OBJECTIVES: To evaluate the image quality of deep learning-based reconstruction (DLR), model-based (MBIR), and hybrid iterative reconstruction (HIR) algorithms for lower-dose (LD) unenhanced head CT and compare it with those of standard-dose (STD) HIR images. METHODS: This retrospective study included 114 patients who underwent unenhanced head CT using the STD (n = 57) or LD (n = 57) protocol on a 320-row CT. STD images were reconstructed with HIR; LD images were reconstructed with HIR (LD-HIR), MBIR (LD-MBIR), and DLR (LD-DLR). The image noise, gray and white matter (GM-WM) contrast, and contrast-to-noise ratio (CNR) at the basal ganglia and posterior fossa levels were quantified. The noise magnitude, noise texture, GM-WM contrast, image sharpness, streak artifact, and subjective acceptability were independently scored by three radiologists (1 = worst, 5 = best). The lesion conspicuity of LD-HIR, LD-MBIR, and LD-DLR was ranked through side-by-side assessments (1 = worst, 3 = best). Reconstruction times of three algorithms were measured. RESULTS: The effective dose of LD was 25% lower than that of STD. Lower image noise, higher GM-WM contrast, and higher CNR were observed in LD-DLR and LD-MBIR than those in STD (all, p ≤ 0.035). Compared with STD, the noise texture, image sharpness, and subjective acceptability were inferior for LD-MBIR and superior for LD-DLR (all, p < 0.001). The lesion conspicuity of LD-DLR (2.9 ± 0.2) was higher than that of HIR (1.2 ± 0.3) and MBIR (1.8 ± 0.4) (all, p < 0.001). Reconstruction times of HIR, MBIR, and DLR were 11 ± 1, 319 ± 17, and 24 ± 1 s, respectively. CONCLUSION: DLR can enhance the image quality of head CT while preserving low radiation dose level and short reconstruction time. KEY POINTS: • For unenhanced head CT, DLR reduced the image noise and improved the GM-WM contrast and lesion delineation without sacrificing the natural noise texture and image sharpness relative to HIR. • The subjective and objective image quality of DLR was better than that of HIR even at 25% reduced dose without considerably increasing the image reconstruction times (24 s vs. 11 s). • Despite the strong noise reduction and improved GM-WM contrast performance, MBIR degraded the noise texture, sharpness, and subjective acceptance with prolonged reconstruction times relative to HIR, potentially hampering its feasibility.


Assuntos
Interpretação de Imagem Radiográfica Assistida por Computador , Tomografia Computadorizada por Raios X , Humanos , Algoritmos , Aprendizado Profundo , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Cabeça/diagnóstico por imagem
3.
AJR Am J Roentgenol ; 219(2): 315-324, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35195431

RESUMO

BACKGROUND. Deep learning-based reconstruction (DLR) may facilitate CT radiation dose reduction, but a paucity of literature has compared lower-dose DLR images with standard-dose iterative reconstruction (IR) images or explored application of DLR to low-tube-voltage scanning in children. OBJECTIVE. The purpose of this study was to assess whether DLR can be used to reduce radiation dose while maintaining diagnostic image quality in comparison with hybrid IR (HIR) and model-based IR (MBIR) for low-tube-voltage pediatric CT. METHODS. This retrospective study included children 6 years old or younger who underwent contrast-enhanced 80-kVp CT with a standard-dose or lower-dose protocol. Standard images were reconstructed with HIR, and lower-dose images were reconstructed with HIR, MBIR, and DLR. Size-specific dose estimate (SSDE) was calculated for both protocols. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were quantified. Two radiologists independently evaluated noise magnitude, noise texture, streak artifact, edge sharpness, and overall quality. Interreader agreement was assessed, and mean values were calculated. To evaluate task-based object detection performance, a phantom was imaged with 80-kVp CT at six doses (SSDE, 0.6-5.3 mGy). Detectability index (d') was calculated from the noise power spectrum and task-based transfer function. Reconstruction methods were compared. RESULTS. Sixty-five children (mean age, 25.0 ± 25.2 months) who underwent CT with standard- (n = 31) or lower-dose (n = 34) protocol were included. SSDE was 54% lower for the lower-dose than for the standard-dose group (1.9 ± 0.4 vs 4.1 ± 0.8 mGy). Lower-dose DLR and MBIR yielded lower image noise and higher SNR and CNR than standard-dose HIR (p < .05). Interobserver agreement on subjective features ranged from a kappa coefficient of 0.68 to 0.78. The readers subjectively scored noise texture, edge sharpness, and overall quality lower for lower-dose MBIR than for standard-dose HIR (p < .001), though higher for lower-dose DLR than for standard-dose HIR (p < .001). In the phantom, DLR provided higher d' than HIR and MBIR at each dose. Object detectability was greater for 2.0-mGy DLR than for 4.0-mGy HIR for low-contrast (3.67 vs 3.57) and high-contrast (1.20 vs 1.04) objects. CONCLUSION. Compared with IR algorithms, DLR results in substantial dose reduction with preserved or even improved image quality for low-tube-voltage pediatric CT. CLINICAL IMPACT. Use of DLR at 80 kVp allows greater dose reduction for pediatric CT than do current IR techniques.


Assuntos
Aprendizado Profundo , Interpretação de Imagem Radiográfica Assistida por Computador , Algoritmos , Criança , Pré-Escolar , Redução da Medicação , Humanos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
4.
Radiographics ; 41(7): 1936-1953, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34597178

RESUMO

Optimizing the CT acquisition parameters to obtain diagnostic image quality at the lowest possible radiation dose is crucial in the radiosensitive pediatric population. The image quality of low-dose CT can be severely degraded by increased image noise with filtered back projection (FBP) reconstruction. Iterative reconstruction (IR) techniques partially resolve the trade-off relationship between noise and radiation dose but still suffer from degraded noise texture and low-contrast detectability at considerably low-dose settings. Furthermore, sophisticated model-based IR usually requires a long reconstruction time, which restricts its clinical usability. With recent advances in artificial intelligence technology, deep learning-based reconstruction (DLR) has been introduced to overcome the limitations of the FBP and IR approaches and is currently available clinically. DLR incorporates convolutional neural networks-which comprise multiple layers of mathematical equations-into the image reconstruction process to reduce image noise, improve spatial resolution, and preserve preferable noise texture in the CT images. For DLR development, numerous network parameters are iteratively optimized through an extensive learning process to discriminate true attenuation from noise by using low-dose training and high-dose teaching image data. After rigorous validations of network generalizability, the DLR engine can be used to generate high-quality images from low-dose projection data in a short reconstruction time in a clinical environment. Application of the DLR technique allows substantial dose reduction in pediatric CT performed for various clinical indications while preserving the diagnostic image quality. The authors present an overview of the basic concept, technical principles, and image characteristics of DLR and its clinical feasibility for low-dose pediatric CT. ©RSNA, 2021.


Assuntos
Aprendizado Profundo , Algoritmos , Inteligência Artificial , Criança , Humanos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Tomografia Computadorizada por Raios X
5.
Artigo em Japonês | MEDLINE | ID: mdl-30662030

RESUMO

To simplify a procedure of the observer study with Ura's method of Scheffé's paired comparison and to improve experimental accuracy, we developed a software package to automatically analyze observer study data obtained by using a computer interface developed specially for the ROC observer study. Simulated low-dose CT images were used to demonstrate practical utility of this proposed method with a software package, in terms of a statistical analysis of the change of noise property due to the change of exposure dose. Six radiological technologists were participated in this observer study and compared each of six sample images selected at lower lung and liver slices with dose levels of 100, 80, 60, 40, 20, 10% per case. In the statistical analysis, the average psychological measures were highly correlated with the dose levels (lower lungs: R=0.95, liver: R=0.99). In addition, there were statistically significant differences in all combination of dose levels in liver slices. In conclusion, we demonstrated practical utility of this proposed method in terms of simplification of experimental procedure and the consistency of the analytic results.


Assuntos
Processamento de Imagem Assistida por Computador , Software , Tomografia Computadorizada por Raios X , Análise por Pareamento , Variações Dependentes do Observador , Doses de Radiação
6.
Phys Eng Sci Med ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38884668

RESUMO

This study aimed to evaluate the impact of radiation dose and focal spot size on the image quality of super-resolution deep-learning reconstruction (SR-DLR) in comparison with iterative reconstruction (IR) and normal-resolution DLR (NR-DLR) algorithms for cardiac CT. Catphan-700 phantom was scanned on a 320-row scanner at six radiation doses (small and large focal spots at 1.4-4.3 and 5.8-8.8 mGy, respectively). Images were reconstructed using hybrid-IR, model-based-IR, NR-DLR, and SR-DLR algorithms. Noise properties were evaluated through plotting noise power spectrum (NPS). Spatial resolution was quantified with task-based transfer function (TTF); Polystyrene, Delrin, and Bone-50% inserts were used for low-, intermediate, and high-contrast spatial resolution. The detectability index (d') was calculated. Image noise, noise texture, edge sharpness of low- and intermediate-contrast objects, delineation of fine high-contrast objects, and overall quality of four reconstructions were visually ranked. Results indicated that among four reconstructions, SR-DLR yielded the lowest noise magnitude and NPS peak, as well as the highest average NPS frequency, TTF50%, d' values, and visual rank at each radiation dose. For all reconstructions, the intermediate- to high-contrast spatial resolution was maximized at 4.3 mGy, while the lowest noise magnitude and highest d' were attained at 8.8 mGy. SR-DLR at 4.3 mGy exhibited superior noise performance, intermediate- to high-contrast spatial resolution, d' values, and visual rank compared to the other reconstructions at 8.8 mGy. Therefore, SR-DLR may yield superior diagnostic image quality and facilitate radiation dose reduction compared to the other reconstructions, particularly when combined with small focal spot scanning.

7.
Acad Radiol ; 30(3): 431-440, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35738988

RESUMO

RATIONALE AND OBJECTIVES: To evaluate the image properties of lung-specialized deep-learning-based reconstruction (DLR) and its applicability in ultralow-dose CT (ULDCT) relative to hybrid- (HIR) and model-based iterative-reconstructions (MBIR). MATERIALS AND METHODS: An anthropomorphic chest phantom was scanned on a 320-row scanner at 50-mA (low-dose-CT 1 [LDCT-1]), 25-mA (LDCT-2), and 10-mA (ULDCT). LDCT were reconstructed with HIR; ULDCT images were reconstructed with HIR (ULDCT-HIR), MBIR (ULDCT-MBIR), and DLR (ULDCT-DLR). Image noise and contrast-to-noise ratio (CNR) were quantified. With the LDCT images as reference standards, ULDCT image qualities were subjectively scored on a 5-point scale (1 = substantially inferior to LDCT-2, 3 = comparable to LDCT-2, 5 = comparable to LDCT-1). For task-based image quality analyses, a physical evaluation phantom was scanned at seven doses to achieve the noise levels equivalent to chest phantom; noise power spectrum (NPS) and task-based transfer function (TTF) were evaluated. Clinical ULDCT (10-mA) images obtained in 14 nonobese patients were reconstructed with HIR, MBIR, and DLR; the subjective acceptability was ranked. RESULTS: Image noise was lower and CNR was higher in ULDCT-DLR and ULDCT-MBIR than in LDCT-1, LDCT-2, and ULDCT-HIR (p < 0.01). The overall quality of ULDCT-DLR was higher than of ULDCT-HIR and ULDCT-MBIR (p < 0.01), and almost comparable with that of LDCT-2 (mean score: 3.4 ± 0.5). DLR yielded the highest NPS peak frequency and TTF50% for high-contrast object. In clinical ULDCT images, the subjective acceptability of DLR was higher than of HIR and MBIR (p < 0.01). CONCLUSION: DLR optimized for lung CT improves image quality and provides possible greater dose optimization opportunity than HIR and MBIR.


Assuntos
Aprendizado Profundo , Humanos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Pulmão/diagnóstico por imagem , Algoritmos
8.
Yakugaku Zasshi ; 142(4): 341-344, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-35370189

RESUMO

Nowadays, medical big data has been developed and made available in a variety of fields such as epidemiology and pharmacovigilance. Spontaneous reporting databases are one category of medical big data and that has been adequate for analysing events related to side effects that rarely occur in general practice. These data are freely available in several countries. In Japan, the Pharmaceuticals and Medical Devices Agency has developed the Japanese Adverse Drug Event Report (JADER), and the Food and Drug Administration (FDA) developed the FDA Adverse Events Reporting System (FAERS) in the United States. Since the release of these medical big data, many researchers in academic and research setting have accessed them, but it is still difficult for many medical professionals to analyse these data due to costs and operation of requisite statistical software. In this section, we give some tips to study spontaneous reporting databases resulting from our learning experiences.


Assuntos
Sistemas de Notificação de Reações Adversas a Medicamentos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Humanos , Farmacovigilância , Software , Estados Unidos/epidemiologia , United States Food and Drug Administration
9.
Eur J Radiol ; 151: 110280, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35381567

RESUMO

PURPOSE: This clinical and phantom study aimed to evaluate the impact of deep learning-based reconstruction (DLR) on image quality and its radiation dose optimization capability for multiphase hepatic CT relative to hybrid iterative reconstruction (HIR). METHODS: Task-based image quality was assessed with a physical evaluation phantom; the high- and low-contrast detectability of HIR and DLR images were computed from the noise power spectrum and task-based transfer function at five different size-specific dose estimate (SSDE) values in the range 5.3 to 18.0-mGy. For the clinical study, images of 73 patients who had undergone multiphase hepatic CT under both standard-dose (STD) and lower-dose (LD) examination protocols within a time interval of about four-months on average, were retrospectively examined. STD images were reconstructed with HIR, while LD with HIR (LD-HIR) and DLR (LD-DLR). SSDE, quantitative image noise, and contrast-to-noise ratio (CNR) were compared between protocols. The noise magnitude, noise texture, streak artifact, image sharpness, interface smoothness, and overall image quality were subjectively rated by two independent radiologists. RESULTS: In phantom study, the high- and low-contrast detectability of DLR images obtained at 5.3-mGy and 7.3-mGy, respectively, were slightly higher than those obtained with HIR at the STD protocol dose (18.0-mGy). In clinical study, LD-DLR yielded lower image noise, higher CNR, and higher subjective scores for all evaluation criteria than STD (all, p ≤ 0.05), despite having 52.8% lower SSDE (8.0 ± 2.5 vs. 16.8 ± 3.4-mGy). CONCLUSIONS: DLR improved the subjective and objective image quality of multiphase hepatic CT compared with HIR techniques, even at approximately half the radiation dose.


Assuntos
Aprendizado Profundo , Infecções Sexualmente Transmissíveis , Algoritmos , Humanos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
10.
Phys Med ; 83: 46-51, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33706150

RESUMO

PURPOSE: To generate pseudo low monoenergetic CT images of the abdomen from 120-kVp CT images with cGAN. MATERIALS AND METHODS: We retrospectively included 48 patients who underwent contrast-enhanced abdominal CT using dual-energy CT. We reconstructed paired data sets of 120 kVp CT images and virtual low monoenergetic (55-keV) CT images. cGAN was prepared to generate pseudo 55-keV CT images from 120-kVp CT images. The pseudo 55 keV CT images in epoch 10, 50, 100, and 500 were compared to the 55 keV images generated using peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM). RESULTS: The PSNRs were 28.0, 28.5, 28.6, and 28.8 at epochs 10, 50, 100, and 500, respectively. The SSIM was approximately constant from epochs 50 to 500. CONCLUSION: Pseudo low monoenergetic abdominal CT images were generated from 120-kVp CT images using cGAN, and the images had good quality similar to that of monochromatic images obtained with DECT software.


Assuntos
Abdome , Tomografia Computadorizada por Raios X , Humanos , Interpretação de Imagem Radiográfica Assistida por Computador , Estudos Retrospectivos , Razão Sinal-Ruído , Tomógrafos Computadorizados
11.
Acad Radiol ; 28(5): e119-e126, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-32402786

RESUMO

RATIONALE AND OBJECTIVES: To clarify the accuracy of two measurement methods for myocardial extracellular volume (ECV) quantification (ie, the standard subtraction method [ECVsub] and the dual-energy iodine method [ECViodine]) with the use of cardiac CT in comparison to cardiac magnetic resonance imaging (CMR) as a reference standard. MATERIALS AND METHODS: Equilibrium phase cardiac images of 21 patients were acquired with a dual-layer spectral detector CT and CMR, and the images were retrospectively analyzed. CT-ECV was calculated using ECVsub and ECViodine. The correlation between the ECV values measured by each method was assessed. Bland-Altman analysis was used to identify systematic errors and to determine the limits of agreement between the CT-ECV and CMR-ECV values. Root mean squared errors and residual values for the ECVsub and ECViodine were also assessed. RESULTS: The correlations between ECVsub and ECViodine for both septal and global measurement were r = 0.95 (p < 0.01) and 0.91 (p < 0.01), respectively, while those between the mean ECVsub and CMR-ECV were r = 0.90 (septal, p < 0.01) and 0.84 (global, p < 0.01), and those between ECViodine and CMR-ECV were r = 0.94 (septal, p < 0.01) and 0.95 (global, p < 0.01). Bland-Altman plots showed lower 95% limits of agreement between ECViodine and CMR-ECV compared with that between ECVsub and CMR-ECV in both septal and global measurement. The root mean squared error of ECVsub was higher than that of ECViodine. The mean residual value of ECVsub was significantly higher than that of ECViodine. CONCLUSION: ECViodine yielded more accurate myocardial ECV quantification than ECVsub, and provided a comparable ECV value to that obtained by CMR.


Assuntos
Iodo , Meios de Contraste , Humanos , Imageamento por Ressonância Magnética , Imagem Cinética por Ressonância Magnética , Miocárdio , Valor Preditivo dos Testes , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
12.
Mod Rheumatol ; 20(3): 238-43, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20143119

RESUMO

We prospectively compared the anti-inflammatory and antidyslipidemic effects of fenofibrate and statins in rheumatoid arthritis (RA) patients. Forty-four RA patients [male (M) = 7, female (F) = 37] with dyslipidemia were enrolled in this 6-month study and randomly allocated to the fenofibrate (2 M + 21 F = 23) or statins (5 M + 16 F = 21) group. We measured blood chemistry (serum lipid profile, sugar, urate, and gamma-glutamyl transpeptidase) and blood pressure 2 h after breakfast. Visual analog scale (VAS), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and prednisolone (PSL) dosage were also recorded immediately before and after the study. Fenofibrate, but not statins, significantly decreased serum levels of total cholesterol, low-density lipoprotein-cholesterol, and triglycerides (all p < 0.05). A significant improvement in VAS was observed in both the fenofibrate group (49.1 +/- 24.7 --> 14.7 +/- 11.2; p < 0.0001) and the statins group (47.4 +/- 29.7 --> 20.2 +/- 16.5; p < 0.001). PSL dosage significantly decreased only in the fenofibrate group (3.58 +/- 2.68 --> 2.00 +/- 2.22 mg/day; p < 0.01). Significant correlation was observed between VAS and CRP in the fenofibrate group (p < 0.05). Fenofibrate showed more anti-inflammatory and antidyslipidemic activity than statins in RA.


Assuntos
Artrite Reumatoide/tratamento farmacológico , Dislipidemias/tratamento farmacológico , Fenofibrato/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Inflamação/tratamento farmacológico , Idoso , Artrite Reumatoide/sangue , Artrite Reumatoide/complicações , Dislipidemias/sangue , Dislipidemias/complicações , Feminino , Humanos , Hipolipemiantes/uso terapêutico , Inflamação/sangue , Inflamação/complicações , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estatísticas não Paramétricas , Resultado do Tratamento
13.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 66(11): 1467-73, 2010 Nov 20.
Artigo em Japonês | MEDLINE | ID: mdl-21099177

RESUMO

Selection of the signal is one of the major factors in a receiver operating characteristic (ROC) study for evaluating the diagnostic accuracy of medical imaging systems. We investigated the effect of signal selections in ROC studies which were applied to evaluate a difference between the two systems. Each of 50 positive and 50 negative images obtained with and without two different types of phantom signals, but with the same background noise and two different digital imaging systems, were used as case samples. We assumed that two different types of phantom signal could be related to image resolution and graininess, respectively. We employed two systems which were assumed to have advantages in resolution and graininess, respectively. Twelve observers participated in this ROC study, which aimed to compare two parameter settings in computed radiography systems. A statistical significance test considering case and reader variations was conducted for each of the ROC data sets with two different signals. As results, p values obtained in the statistical significance test were varied by changing the type of signal even if the same observer group participated and the same two different systems were compared (p value = 0.0003 and 0.0944). In conclusion, it was suggested that the selection of phantom signal for an ROC study could lead to different conclusions if the type of phantom signal was not matched to the purpose of the ROC study.


Assuntos
Curva ROC , Intensificação de Imagem Radiográfica , Interpretação Estatística de Dados , Humanos , Imagens de Fantasmas
14.
J Radiat Res ; 50(3): 253-9, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19398855

RESUMO

Werner syndrome (WS) is an autosomal recessive disease characterized by premature aging and caused by mutations of the WRN gene mapped at 8p12. To examine functional complementation of WS phenotypes, we introduced a normal human chromosome 8 into a strain of WS fibroblasts (WS3RGB) immortalized by expressing a human telomerase reverse transcriptase subunit (hTERT) gene. Here, we demonstrate that the abnormal WS phenotypes including cellular sensitivities to 4-nitroquinoline-1-oxide (4NQO) and hydroxy urea (HU), and chromosomal radiosensitivity at G(2) phase are corrected by expression of the WRN gene mediated by introducing a chromosome 8. This indicates that those multiple abnormal WS phenotypes are derived from a primary, but not secondary, defect in the WRN gene.


Assuntos
Cromossomos Humanos Par 8/genética , Fibroblastos , Fenótipo , Telomerase/metabolismo , Síndrome de Werner/genética , 4-Nitroquinolina-1-Óxido/farmacologia , Animais , Western Blotting , Linhagem Celular Transformada , Exodesoxirribonucleases/genética , Exodesoxirribonucleases/metabolismo , Fase G2 , Expressão Gênica , Humanos , Camundongos , Mutação , RecQ Helicases/genética , RecQ Helicases/metabolismo , Helicase da Síndrome de Werner
15.
Artigo em Inglês | MEDLINE | ID: mdl-30858980

RESUMO

BACKGROUND: There have been debates about the association between the administration of glucocorticoids and the development of acute pancreatitis, since many anecdotal cases of this adverse event were affected either by concomitant diseases (such as systemic lupus erythematosus, SLE) that may develop acute pancreatitis without glucocorticoid treatment or by co-administered drugs with high risk for the event. The aim of the present study was to explore whether disproportionally elevated signals of developing acute pancreatitis may be detected in patients receiving glucocorticoids as compared those receiving other drugs. METHODS: We retrieved spontaneously reported cases of acute pancreatitis and clinically related adverse events (target events) from the US Food and Drug Administration Adverse Event Reporting System (FAERS) using 18 preferred terms (PTs). Target drugs studied were cortisol, cortisone, prednisolone, methylprednisolone, triamcinolone, dexamethasone, and betamethasone. After cleaning the data, we calculated reporting odds ratios (RORs) and 95% confidence intervals (CIs) of acute pancreatitis in patients who received one of the glucocorticoids. RORs were calculated for each glucocorticoid using all reported cases irrespective of reporters' judgement about the contribution of the target drugs to events [i.e., primary suspected medication (PS), secondary suspected medication (SS), concomitant medication (C) and interacting (I)] and using cases with higher certainty of contribution (PS and SS), separately. When the lower limit of 95% CI of a ROR signal exceeded 1.0, the signal was considered statistically significant. RESULTS: The RORs (95% CIs) calculated using all reported cases (PS, SS, C, and I) for cortisol (1.68; 1.43-1.98), prednisolone (1.33; 1.19-1.47), methylprednisolone (1.77; 1.55-2.02) were significant, whereas those for other target drugs were insignificant. Using the cases in which target drugs were considered to contribute the events with higher certainty (PS or SS), RORs for prednisolone (1.31; 1.10-1.55), methylprednisolone (1.62; 1.30-2.01), and dexamethasone (1.27; 1.10-1.47) were considered significant, whereas those for others were insignificant. Regarding the performance of PTs for detecting signals (RORs) associated with acute pancreatitis from FAERS database, "pancreatitis acute" gave RORs with higher significance than others, whereas more specific PTs, "haemorrhagic necrotic pancreatitis", "ischaemic pancreatitis", "pancreatic necrosis" and "pancreatitis necrotising", gave RORs with greater magnitude. CONCLUSION: The present study demonstrated that the overrepresentation of signals for acute pancreatitis may be detected for prednisolone, methylprednisolone, and some others in the FAERS database.(372 words).

16.
Intern Med ; 58(1): 109-113, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30146558

RESUMO

Werner syndrome (WS) confers a high risk of the development of neoplasias, including hematological malignancies, and curative treatment for these malignancies is difficult to achieve. A 44-year-old man with myelodysplastic syndrome was admitted to our hospital. He was diagnosed with mutation-proven WS. He underwent cord blood transplantation (CBT) following fludarabine, busulfan, and melphalan administration. A chimerism analysis of his marrow blood on day 62 showed a donor pattern >95%, which confirmed engraftment. The patient lived for 15 months while maintaining remission of MDS without treatment-related toxicity. Our case shows that CBT can be a treatment modality for WS patients with hematological malignancies.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical , Síndromes Mielodisplásicas/terapia , Síndrome de Werner/terapia , Adulto , Antineoplásicos/uso terapêutico , Humanos , Masculino , Síndromes Mielodisplásicas/etiologia , Transplante Homólogo , Resultado do Tratamento , Síndrome de Werner/complicações
17.
Cancer Sci ; 99(5): 843-8, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18312465

RESUMO

Werner syndrome (WS) is an autosomal recessive genetic disorder causing premature aging, and WRN has been identified as the causative gene of WS. The product of the WRN gene (WRN) acts as a DNA helicase with exonuclease activity, and data have accumulated showing that the WRN gene strongly participates in carcinogenesis: (1) the normal WRN gene likely participates in the immortalization of B-lymphoblastoid cell lines through telomeric crisis caused by telomere shortening, (2) a much higher incidence of rare cancers occurs in WS patients than in other kinds of patients, and (3) levels of WRN expressed in virus-transformed cells and cancer cells are usually markedly up-regulated and are inversely correlated with the sensitivity of these cells against various genotoxins, including camptothecin. In this paper, we review the events that show a close correlation of the WRN gene and WRN with carcinogenesis and their underlying molecular mechanisms.


Assuntos
DNA Helicases/metabolismo , Exodesoxirribonucleases/metabolismo , Mutagênicos/toxicidade , Neoplasias/genética , RecQ Helicases/metabolismo , Transformação Celular Neoplásica , Instabilidade Cromossômica , DNA Helicases/genética , Reparo do DNA , Exodesoxirribonucleases/genética , Humanos , Modelos Biológicos , Mutação , Neoplasias/enzimologia , RecQ Helicases/genética , Telômero/metabolismo , Síndrome de Werner/genética , Síndrome de Werner/metabolismo , Helicase da Síndrome de Werner
18.
FEBS Lett ; 582(17): 2479-83, 2008 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-18588880

RESUMO

Caloric restriction (CR) is known to promote longevity in various species. Sirtuin-mediated deacetylation has been shown to be related to the promotion of longevity in some species. Here, we show that CR of rats led to an increase in the level of Werner syndrome protein (WRN), a recognized DNA repair protein. In addition, CR simultaneously increased the level of SIRT1, a mammalian sirtuin. In HEK293T cells, sirtuin inhibitors decreased the WRN level, and this effect was suppressed by proteasomal inhibitors. Furthermore, we found a decrease in the WRN level in Sirt1-deficient mice. These results indicate that sirtuin-mediated deacetylation stabilizes WRN. STRUCTURED SUMMARY:


Assuntos
Restrição Calórica , Exodesoxirribonucleases/metabolismo , RecQ Helicases/metabolismo , Sirtuínas/metabolismo , Acetilação , Animais , Inibidores Enzimáticos/farmacologia , Estabilidade Enzimática , Humanos , Fígado/enzimologia , Camundongos , Camundongos Mutantes , Complexo de Endopeptidases do Proteassoma/metabolismo , Ratos , Sirtuína 1 , Sirtuínas/antagonistas & inibidores , Sirtuínas/genética , Helicase da Síndrome de Werner
19.
Intractable Rare Dis Res ; 7(4): 229-235, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30560014

RESUMO

A series of our "inflammageing" study examining serum samples from a maximum of 217 healthy Japanese individuals aged between 1 and 100 years and mutation-proven 40 patients with Werner syndrome (WS) indicated normal aging-associated elevations of highly sensitive CRP (hsCRP) and matrix metalloproteinase-9 (MMP-9). To further study the contribution of environmental factors such as persistent herpes viral infection to inflammageing, IgG antibodies against varicella/zoster virus (VZV) and cytomegalovirus (CMV) were examined in the same serum samples as has been done for hsCRP and MMP-9 analyses. The mean levels of serum IgG viral antibodies were comparable between normal (mean ± SE: 31.0 ± 4.3 unit) and WS (38.6 ± 7.6) for CMV, and between normal (42.0 ± 12.2) and WS (29.8 ± 3.8) for VZV, respectively. Significant associations of aging with IgG anti-CMV antibody were in normal aging (p = 0.023) and WS (p = 0.037), but not with IgG VZV in both conditions. Aging-associated change of IgG anti-CMV antibody titer in WS increased significantly (1.32 times higher) compared with normal aging (p = 0.037). IgG anti-CMV level was significantly elevated in the male gender than female in both conditions (p = 0.006). Elevated hsCRP level was significantly associated with IgG anti-CMV (p = 0.016) and IgG anti-VZV (p = 0.008) antibodies in normal aging, but not in WS. Serum MMP-9 was significantly associated with IgG anti-CMV level (p = 0.0002) in normal aging, but not in WS. Persistent herpes viral infection may constitute a part of "inflammageing" in normal aging and WS.

20.
Magn Reson Med Sci ; 17(1): 35-41, 2018 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-28515409

RESUMO

PURPOSE: To evaluate the effect of a composite radiofrequency (RF) pulse on saturation recovery (SR) myocardial T1 mapping using a 3T MR system. MATERIALS AND METHODS: Phantom and in vivo studies were performed with a clinical 3T MR scanner. Accuracy and reproducibility of the SR T1 mapping using conventional and composite RF pulses were first compared in phantom experiments. An in vivo study was performed of 10 healthy volunteers who were imaged with conventional and composite RF pulse methods twice each. In vivo reproducibility of myocardial T1 value and the inter-segment variability were assessed. RESULTS: The phantom study revealed significant differences in the mean T1 values between the two methods, and the reproducibility for the composite RF pulse was significantly smaller than that for the conventional RF pulse. For both methods, the correlations of the reference and measured T1 values were excellent (r2 = 0.97 and 0.98 for conventional and composite RF pulses, respectively). The in vivo study showed that the mean T1 value for composite RF pulse was slightly lower than that for conventional RF pulse, but this difference was not significant (P = 0.06). The inter-segment variability for the composite RF pulse was significantly smaller than that for conventional RF pulse (P < 0.01). Inter-scan correlations of T1 measurements of the first and second scans were highly and weakly correlated to composite RF pulses (r = 0.83 and 0.29, respectively). CONCLUSION: SR T1 mapping using composite RF pulse provides accurate quantification of T1 values and can lessen measurement variability and enable reproducible T1 measurements.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Miocárdio/patologia , Ondas de Rádio , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Reprodutibilidade dos Testes
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