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2.
Sci Rep ; 10(1): 4623, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165702

RESUMO

Retinal fundus images are used to detect organ damage from vascular diseases (e.g. diabetes mellitus and hypertension) and screen ocular diseases. We aimed to assess convolutional neural network (CNN) models that predict age and sex from retinal fundus images in normal participants and in participants with underlying systemic vascular-altered status. In addition, we also tried to investigate clues regarding differences between normal ageing and vascular pathologic changes using the CNN models. In this study, we developed CNN age and sex prediction models using 219,302 fundus images from normal participants without hypertension, diabetes mellitus (DM), and any smoking history. The trained models were assessed in four test-sets with 24,366 images from normal participants, 40,659 images from hypertension participants, 14,189 images from DM participants, and 113,510 images from smokers. The CNN model accurately predicted age in normal participants; the correlation between predicted age and chronologic age was R2 = 0.92, and the mean absolute error (MAE) was 3.06 years. MAEs in test-sets with hypertension (3.46 years), DM (3.55 years), and smoking (2.65 years) were similar to that of normal participants; however, R2 values were relatively low (hypertension, R2 = 0.74; DM, R2 = 0.75; smoking, R2 = 0.86). In subgroups with participants over 60 years, the MAEs increased to above 4.0 years and the accuracies declined for all test-sets. Fundus-predicted sex demonstrated acceptable accuracy (area under curve > 0.96) in all test-sets. Retinal fundus images from participants with underlying vascular-altered conditions (hypertension, DM, or smoking) indicated similar MAEs and low coefficients of determination (R2) between the predicted age and chronologic age, thus suggesting that the ageing process and pathologic vascular changes exhibit different features. Our models demonstrate the most improved performance yet and provided clues to the relationship and difference between ageing and pathologic changes from underlying systemic vascular conditions. In the process of fundus change, systemic vascular diseases are thought to have a different effect from ageing. Research in context. Evidence before this study. The human retina and optic disc continuously change with ageing, and they share physiologic or pathologic characteristics with brain and systemic vascular status. As retinal fundus images provide high-resolution in-vivo images of retinal vessels and parenchyma without any invasive procedure, it has been used to screen ocular diseases and has attracted significant attention as a predictive biomarker for cerebral and systemic vascular diseases. Recently, deep neural networks have revolutionised the field of medical image analysis including retinal fundus images and shown reliable results in predicting age, sex, and presence of cardiovascular diseases. Added value of this study. This is the first study demonstrating how a convolutional neural network (CNN) trained using retinal fundus images from normal participants measures the age of participants with underlying vascular conditions such as hypertension, diabetes mellitus (DM), or history of smoking using a large database, SBRIA, which contains 412,026 retinal fundus images from 155,449 participants. Our results indicated that the model accurately predicted age in normal participants, while correlations (coefficient of determination, R2) in test-sets with hypertension, DM, and smoking were relatively low. Additionally, a subgroup analysis indicated that mean absolute errors (MAEs) increased and accuracies declined significantly in subgroups with participants over 60 years of age in both normal participants and participants with vascular-altered conditions. These results suggest that pathologic retinal vascular changes occurring in systemic vascular diseases are different form the changes in spontaneous ageing process, and the ageing process observed in retinal fundus images may saturate at age about 60 years. Implications of all available evidence. Based on this study and previous reports, the CNN could accurately and reliably predict age and sex using retinal fundus images. The fact that retinal changes caused by ageing and systemic vascular diseases occur differently motivates one to understand the retina deeper. Deep learning-based fundus image reading may be a more useful and beneficial tool for screening and diagnosing systemic and ocular diseases after further development.

3.
Ophthalmology ; 127(1): 85-94, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31281057

RESUMO

PURPOSE: To develop and evaluate deep learning models that screen multiple abnormal findings in retinal fundus images. DESIGN: Cross-sectional study. PARTICIPANTS: For the development and testing of deep learning models, 309 786 readings from 103 262 images were used. Two additional external datasets (the Indian Diabetic Retinopathy Image Dataset and e-ophtha) were used for testing. A third external dataset (Messidor) was used for comparison of the models with human experts. METHODS: Macula-centered retinal fundus images from the Seoul National University Bundang Hospital Retina Image Archive, obtained at the health screening center and ophthalmology outpatient clinic at Seoul National University Bundang Hospital, were assessed for 12 major findings (hemorrhage, hard exudate, cotton-wool patch, drusen, membrane, macular hole, myelinated nerve fiber, chorioretinal atrophy or scar, any vascular abnormality, retinal nerve fiber layer defect, glaucomatous disc change, and nonglaucomatous disc change) with their regional information using deep learning algorithms. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve and sensitivity and specificity of the deep learning algorithms at the highest harmonic mean were evaluated and compared with the performance of retina specialists, and visualization of the lesions was qualitatively analyzed. RESULTS: Areas under the receiver operating characteristic curves for all findings were high at 96.2% to 99.9% when tested in the in-house dataset. Lesion heatmaps highlight salient regions effectively in various findings. Areas under the receiver operating characteristic curves for diabetic retinopathy-related findings tested in the Indian Diabetic Retinopathy Image Dataset and e-ophtha dataset were 94.7% to 98.0%. The model demonstrated a performance that rivaled that of human experts, especially in the detection of hemorrhage, hard exudate, membrane, macular hole, myelinated nerve fiber, and glaucomatous disc change. CONCLUSIONS: Our deep learning algorithms with region guidance showed reliable performance for detection of multiple findings in macula-centered retinal fundus images. These interpretable, as well as reliable, classification outputs open the possibility for clinical use as an automated screening system for retinal fundus images.

4.
Retina ; 40(3): 468-476, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30422938

RESUMO

PURPOSE: To study the association between the risk of massive submacular hemorrhage (SMH) and polyp regression after initial treatment of polypoidal choroidal vasculopathy using long-term follow-up data. METHODS: Retrospective study of 223 patients who were diagnosed with polypoidal choroidal vasculopathy and were followed up for up to 11 years. Subjects were categorized into "regression" and "no regression" groups, according to their polyp status after the initial treatment. Kaplan-Meier survival analyses were performed on development of massive SMH. The association between treatment methods and the occurrence of massive SMH was also analyzed. RESULTS: The incidence rates of massive SMH at 3, 6, and 9 years in the "no regression" group were 6.50, 22.59, and 38.03%, respectively, and in the "regression" group were 1.14, 6.47, and 10.92%, respectively (P = 0.005, log-rank test). The hazard ratio of massive SMH was 3.677 for cluster-type polyps and 0.271 for polyp regression after initial treatment. A higher rate of polyp regression was associated with photodynamic therapy (PDT) than anti-VEGF monotherapy (64.4 vs. 33.3%, P < 0.001). Additional anti-VEGF treatments after initial PDT showed lower risk of massive SMH than PDT only. (9.5 vs 38.5%, P = 0.005). CONCLUSION: The long-term risk of massive SMH after initial treatment on polypoidal choroidal vasculopathy is significantly higher in eyes with persistent polyps than those with regressed polyps. Ophthalmologists should pay attention to the risk of massive SMH and the polyp status when treating polypoidal choroidal vasculopathy.

5.
J Korean Med Sci ; 34(48): e306, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31833263

RESUMO

BACKGROUND: Despite the significant disease burden, there is a paucity of data addressing the population-based incidence of acute angle closure glaucoma (AACG). Therefore, we estimated the nationwide, population-based standardized incidence rate of AACG in Korea. METHODS: We conducted a nationwide, population-based, retrospective study using the database of National Health Insurance (NHI) system, which includes the entire Korean population (approximately 50 million people) from 2009 to 2015. We identified patients with incident AACG during the 5-year study period from 2011 to 2015 based on their diagnosis and AACG-related treatments (laser iridotomy and cataract surgery), and estimated age- and gender-standardized incidence rate of AACG during the study period. RESULTS: We identified 11,049 patients (8,022 women, 72.6%) with incident AACG during the 5-year study period. Of these, after excluding 6 patients under 20 years old, 11,043 patients (8,020 women, 72.6%) aged ≥ 20 years were included in the analysis. The average standardized incidence rate during the 5-year study period was 59.95 (95% confidence interval [CI], 58.87-61.03) per 1,000,000 person-years. The incidence rates increased sharply with age and peaked at individuals aged 75-79 years; in men, those peaked at the same age group, however, in women, those peaked at individuals aged 70-74 years. Women has a 2.56 folds higher incidence rate (85.84 [95% CI, 84.03-87.66] per 1,000,000 person-years) than men (33.48 [95% CI, 32.33-34.62] per 1,000,000 person-years). CONCLUSION: The present study provides detailed estimates for AACG incidence according to all age groups and gender through the 5-year study period.

6.
Nanomedicine ; 24: 102141, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31830613

RESUMO

Lysyl oxidase (LOX) is a cell-secreted amine oxidase that crosslinks collagen and elastin in extracellular microenvironment. LOX-traceable nanoparticles (LOXab-NPs) consisting of LOX antibodies (LOXab) and paclitaxel, can accumulate at high concentrations at radiation-treated target sites, as a tumor-targeting drug carrier for chemotherapy. Tumor-targeting and anticancer effects of PLGA based LOXab-NPs in vitro and in vivo were evaluated at radiation-targeted site. In the in vivo A549 lung carcinoma xenograft model, we showed highly specific tumor targeting (above 7.0 times higher) of LOXab-NPs on irradiated tumors. Notably, systemically administered NPs delayed tumor growth, reducing tumor volumes by more than 2 times compared with non-irradiated groups (222% vs. >500%) over 2 weeks. Radiotropic LOXab-NPs can serve as chemotherapeutic vehicles for combined targeted chemo-radiotherapy in clinical oncology.

7.
Sci Rep ; 9(1): 19684, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31873097

RESUMO

In the case of two-dimensional gradient index cavities designed by the conformal transformation optics, we propose a boundary integral equation method for the calculation of resonant mode functions by employing a fictitious space which is reciprocally equivalent to the physical space. Using the Green's function of the interior region of the uniform index cavity in the fictitious space, resonant mode functions and their far-field distributions in the physical space can be obtained. As a verification, resonant modes in limaçon-shaped transformation cavities were calculated and mode patterns and far-field intensity distributions were compared with those of the same modes obtained from the finite element method.

8.
Bioinformatics ; 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31841142

RESUMO

MOTIVATION: Glycan microarrays are capable of illuminating the interactions of glycan-binding proteins (GBPs) against hundreds of defined glycan structures, and have revolutionized the investigations of protein-carbohydrate interactions underlying numerous critical biological activities. However, it is difficult to interpret microarray data and identify structural determinants promoting glycan binding to GBPs due to the ambiguity in microarray fluorescence intensity and complexity in branched glycan structures. To facilitate analysis of glycan microarray data alongside protein structure, we have built the glycan microarray database (GlyMDB), a web-based resource including a searchable database of glycan microarray samples and a toolset for data/structure analysis. RESULTS: The current GlyMDB provides data visualization and glycan-binding motif discovery for 5,203 glycan microarray samples collected from the Consortium for Functional Glycomics. The unique feature of GlyMDB is to link microarray data to PDB structures. The GlyMDB provides different options for database query, and allows users to upload their microarray data for analysis. After search or upload is complete, users can choose the criterion for binder vs. non-binder classification. They can view the signal intensity graph including the binder/non-binder threshold followed by a list of glycan binding motifs. One can also compare the fluorescence intensity data from two different microarray samples. A protein sequence-based search is performed using BLAST to match microarray data with all available PDB structures containing glycans. The glycan ligand information is displayed, and links are provided for structural visualization and redirection to other modules in GlycanStructure.ORG for further investigation of glycan binding sites and glycan structures. AVAILABILITY AND IMPLEMENTATION: http://www.glycanstructure.org/glymdb. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

9.
PLoS One ; 14(11): e0225322, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31725805

RESUMO

We investigated the presence of cerebral small vessel disease (SVD) in patients with nonarteritic anterior ischemic optic neuropathy (NAION) compared to control subjects without NAION to identify the association between NAION and cerebral SVD. We retrospectively reviewed the cases of 63 patients with NAION and 2749 control subjects without any neurologic and ocular diseases including NAION who underwent careful medical interviews, ophthalmic examinations, and magnetic resonance imaging (MRI) studies of the brain. We assessed and compared the degree of cerebral SVD on the MRIs. The patients with NAION presented with cerebral SVD more frequently than controls (68% versus 37%, respectively, p<0.001), which was also observed after adjusting for age, sex, comorbid conditions including hypertension, diabetes, and dyslipidemia, and smoking using the standardized mortality ratio (68% vs. 37%, p<0.001). A multivariate logistic regression analysis showed that the odds of cerebral SVD were 4.86 (95% CI, 2.10 to 11.24, p<0.001) times higher in patients with NAION than in the controls. We found that there was an association between cerebral SVD and NAION even after adjusting for age, sex, and medical histories. Clinicians should consider brain MRI scans in patients with NAION to prevent neurological impairment after cerebral SVD.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31717624

RESUMO

The association between visual impairment and higher mortality remains unclear. In addition, evidence is lacking on the interaction between visual function and physical activity on mortality. We used data of individuals with no disability or with visual impairment among those who participated in the National Health Screening Program in Korea in 2009 or 2010. We constructed Cox proportional hazard models adjusted for potential confounders to evaluate the independent association between visual impairment and mortality. More severe visual impairment was associated with higher all-cause mortality (p-value for trend = 0.03) and mortality due to cardiovascular diseases (p-value for trend = 0.02) and that due to other diseases (p-value for trend = 0.01). We found an interaction on an additive scale between visual impairment and no physical activity on all-cause mortality (relative excess risk due to interaction = 1.34, 95% confidence interval: 0.37, 2.30, p-value = 0.01). When we stratified the study population by physical activity, the association between visual impairment and mortality was only found among individuals who did not engage in regular physical activity (p-value for trend = 0.01). We found an independent association between visual impairment and mortality and modification of this association by physical activity.

11.
BMC Health Serv Res ; 19(1): 828, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31718629

RESUMO

BACKGROUND: The exudative age-related macular degeneration (AMD) causes considerable healthcare costs for patients and healthcare system, which are expected to grow as the population ages. The objective of this study was to assess the incremental economic burden of exudative AMD by comparing total healthcare costs between the exudative AMD group and non-AMD group to understand economic burden related to exudative AMD. METHODS: This retrospective cohort study used the National Health Insurance Service database including the entire Korean population. Exudative AMD group included individuals with at least one claim for ranibizumab and one claim using the registration code for exudative AMD (V201). Non-AMD group was defined as individuals without any claims regarding the diagnostic code of H35.3 or ranibizumab. The exudative AMD group and non-AMD group were matched using a propensity-score model. Incremental healthcare resource utilization and healthcare costs were measured during a one-year follow-up by employing econometric models: ordinary least squares (OLS) with log transformation and heteroscedastic retransformation; and generalized linear model (GLM) with a log link function and gamma distribution. RESULTS: A total of 7119 exudative AMD patients were matched to 7119 non-AMD patients. The number of outpatient visits was higher in the exudative AMD group (P-value < 0.0001), while the length of hospitalization was shorter in exudative AMD group (P-value < 0.0001). Exudative AMD patients had total costs 2.13 times (95%CI, 2.08-2.17) greater than non-AMD group using OLS, and total costs 4.06 times (95%CI, 3.82-4.31) greater than non-AMD group using GLM. Annual incremental total costs were estimated as $5519 (OLS) and $3699 (GLM). CONCLUSIONS: Exudative AMD was associated with significantly increased healthcare costs compared to the non-AMD group. Attention is needed to manage the socioeconomic burden of exudative AMD.


Assuntos
Efeitos Psicossociais da Doença , Custos de Cuidados de Saúde , Degeneração Macular/economia , Degeneração Macular/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Bases de Dados Factuais , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Projetos de Pesquisa , Estudos Retrospectivos
12.
J Am Chem Soc ; 141(49): 19389-19396, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31773957

RESUMO

Two-photon fluorescence microscopy has become an indispensable technique for cellular imaging. Whereas most two-photon fluorescent probes rely on well-known fluorophores, here we report a new fluorophore for bioimaging, namely azulene. A chemodosimeter, comprising a boronate ester receptor motif conjugated to an appropriately substituted azulene, is shown to be an effective two-photon fluorescent probe for reactive oxygen species, showing good cell penetration, high selectivity for peroxynitrite, no cytotoxicity, and excellent photostability.

13.
J Glaucoma ; 28(12): 1067-1073, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31633620

RESUMO

PRECIS: The association between primary open-angle glaucoma (POAG) and subsequent development of chronic kidney disease (CKD) was investigated using a nationwide, population-based, retrospective cohort in South Korea. POAG increases the risk of subsequent CKD development. PURPOSE: The purpose of this study was to investigate the risk of subsequent CKD development in patients with POAG. METHODS: In this nationwide, population-based longitudinal cohort, 1,025,340 beneficiaries in the 2002-2013 Korean National Health Insurance database were included. We identified patients with incident POAG and evaluated the risk of subsequent CKD development using diagnostic codes from the database after 2-year wash-out periods. We applied time-varying covariate Cox regression analyses to determine the effect of POAG on the development of CKD: Model 1 included only POAG as a time-varying covariate; Model 2 included Model 1 and demographic information; and Model 3 included Model 2, comorbidity, comedication, and the Charlson Comorbidity Index score. RESULTS: The fixed cohort included 478,303 eligible subjects, and of these subjects, 1749 suffered incident POAG, and 3157 developed CKD. POAG was associated with an increased risk of CKD development [hazard ratio (HR)=7.63; 95% confidence interval (CI), 5.89-9.87] in Model 1; HR=3.54 (95% CI, 2.73-4.58) in Model 2; and HR=2.90 (95% CI, 2.24-3.76) in Model 3]. CONCLUSION: POAG increased the risk of subsequent CKD in the general population, suggesting that POAG and CKD might share a common pathogenic mechanism.

14.
Transplant Proc ; 51(8): 2575-2581, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31474451

RESUMO

BACKGROUND: This study aimed to investigate the outcomes of kidney transplantation (KT) from deceased acute kidney injury (AKI) donors and analyzed the factors affecting these outcomes. METHODS: All patients who underwent KT from deceased donors at our institution from 1998 to 2016 were retrospectively reviewed. Recipients were divided into the AKI and non-AKI donor groups. We analyzed delayed graft function (DGF), serum creatinine levels at 1 month and 1 year after KT, cold ischemia time, donors' initial and terminal serum creatinine levels, Kidney Donor Profile Index, and patient and graft survival in each group. RESULTS: Of 181 recipients, 30 received kidneys from 21 AKI donors, whereas the remaining 151 received kidneys from donors without AKI. DGF more frequently developed in the AKI donor group than in the non-AKI donor group (40% vs 7.28%; P = .001). Allograft functions at 1 month and 1 year after KT did not differ between the AKI and non-AKI donor groups (1 month: P = .469; 1 year: P = .691). Factors affecting DGF were recipient weight and donor AKI. Recipient factors affecting graft function at 1 year were recipient height, length of hospital stay, serum creatinine levels at 1 month and 6 months, and biopsy-proven acute rejection. Older donor age was the only donor factor that affected graft function at 1 year. CONCLUSION: KT from deceased AKI donors showed a higher DGF rate but favorable patient and graft survival and graft functions. Donor AKI and recipient weight affected DGF, and only older donor age affected graft function at 1 year.


Assuntos
Lesão Renal Aguda , Função Retardada do Enxerto/epidemiologia , Função Retardada do Enxerto/etiologia , Transplante de Rim/métodos , Doadores de Tecidos , Adulto , Fatores Etários , Feminino , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante Homólogo , Transplantes/fisiopatologia
15.
Biol Pharm Bull ; 42(9): 1562-1568, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474716

RESUMO

Chronopharmacology is the study of the varying responses of drugs to changes in biological timing and endogenous periodicities. The dipeptidyl peptidase-4 inhibitor sitagliptin is a globally prescribed anti-hyperglycemic drug. Although dipeptidyl peptidase-4 inhibitors are usually administered once, the specific intake time is generally not mentioned. Therefore, this study aimed at investigating the diurnal effects of sitagliptin-induced anti-hyperglycemia in high-fat diet (HFD)-induced obesity in mice. Five-week-old male C57BL/6J mice were fed normal (control) diet or HFD for 10 weeks. During the last 2 weeks, the mice were administered saline or sitagliptin (10 mg/kg, per os) in the light or dark phase, respectively. At the end of the experiment, the mice were euthanized after an 18 h fasting period, and plasma and tissue samples (liver, kidney, and epididymal white adipose tissues) were collected, or the oral glucose tolerance test was performed. Sitagliptin administration in the light phase significantly decreased plasma glucose levels, insulin levels, hepatic steatosis, and restored the glucose tolerance compared with the HFD group. In contrast, these parameters remained unchanged in the dark phase-treated mice. Our data therefore suggests that sitagliptin portrays definite chronopharmacology, which may provide valuable information on the importance of drug administration timing for maximum pharmacological effects.


Assuntos
Cronoterapia Farmacológica , Hiperglicemia/prevenção & controle , Hipoglicemiantes/administração & dosagem , Obesidade/tratamento farmacológico , Fosfato de Sitagliptina/administração & dosagem , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Animais , Glicemia/análise , Dieta Hiperlipídica , Modelos Animais de Doenças , Glucose/metabolismo , Hiperglicemia/metabolismo , Hipoglicemiantes/uso terapêutico , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Obesidade/sangue , Tamanho do Órgão/efeitos dos fármacos , Fosfato de Sitagliptina/uso terapêutico
16.
Biomed Res Int ; 2019: 5357241, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31485442

RESUMO

Objectives: To investigate the mechanism of rhegmatogenous retinal detachment (RRD) in young and elderly Korean patients based on the results of axial length distribution. Subjects/Methods: We retrospectively reviewed the medical records of 1599 patients with RRD who had bilateral axial length data examined at one center between 2003 and 2018. Axial lengths were measured using ultrasound or IOLMaster500. The frequency of RRD and axial length distribution according to age groups were investigated. Results: Patients with RRD displayed a bimodal distribution across ages with two age groups showing the highest peak at 55-59 years and a second peak at 25-29 years of age. The mean axial length was significantly longer in patients younger than 50 years old than that in patients ≥ 50 years old (26.18 ± 1.86 mm vs. 24.55 ± 1.67 mm, respectively, p < 0.001). The percentage of patients with high myopia (axial length ≥ 26 mm) in patients < 50 years old was higher than that in those ≥ 50 years old (51.9% vs. 15.0%, respectively, p < 0.001; odds ratio, 6.11; 95% confidence interval, 4.83 to 7.74). Conclusions: We found a difference in the prevalence of myopia between young and elderly patients with RRD, which corresponds to a bimodal distribution of RRD incidence in East Asian countries. Our data indicate that myopia or high myopia-induced early vitreous detachment appears to be a major mechanism of occurrence of RRD in young East Asian patients, while senile vitreous liquefaction and detachment is the main mechanism of RRD in elderly patients.


Assuntos
Miopia/epidemiologia , Descolamento Retiniano/epidemiologia , Adulto , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , República da Coreia/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Acuidade Visual/fisiologia
17.
Comput Methods Programs Biomed ; 178: 237-246, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31416552

RESUMO

BACKGROUND AND OBJECTIVE: Retinal fundus images are widely used to diagnose retinal diseases and can potentially be used for early diagnosis and prevention of chronic vascular diseases and diabetes. While various automatic retinal vessel segmentation methods using deep learning have been proposed, they are mostly based on common CNN structures developed for other tasks such as classification. METHODS: We present a novel and simple multi-scale convolutional neural network (CNN) structure for retinal vessel segmentation. We first provide a theoretical analysis of existing multi-scale structures based on signal processing. In previous structures, multi-scale representations are achieved through downsampling by subsampling and decimation. By incorporating scale-space theory, we propose a simple yet effective multi-scale structure for CNNs using upsampling, which we term scale-space approximated CNN (SSANet). Based on further analysis of the effects of the SSA structure within a CNN, we also incorporate residual blocks, resulting in a multi-scale CNN that outperforms current state-of-the-art methods. RESULTS: Quantitative evaluations are presented as the area-under-curve (AUC) of the receiver operating characteristic (ROC) curve and the precision-recall curve, as well as accuracy, for four publicly available datasets, namely DRIVE, STARE, CHASE_DB1, and HRF. For the CHASE_DB1 set, the SSANet achieves state-of-the-art AUC value of 0.9916 for the ROC curve. An ablative analysis is presented to analyze the contribution of different components of the SSANet to the performance improvement. CONCLUSIONS: The proposed retinal SSANet achieves state-of-the-art or comparable accuracy across publicly available datasets, especially improving segmentation for thin vessels, vessel junctions, and central vessel reflexes.


Assuntos
Doenças Retinianas/diagnóstico por imagem , Vasos Retinianos/diagnóstico por imagem , Algoritmos , Área Sob a Curva , Aprendizado Profundo , Reações Falso-Positivas , Fundo de Olho , Humanos , Processamento de Imagem Assistida por Computador , Distribuição Normal , Curva ROC , Processamento de Sinais Assistido por Computador
18.
Obes Res Clin Pract ; 13(5): 505-510, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31466832

RESUMO

Chronopharmacology is the study of the varying responses of drugs to changes in biological timing and endogenous periodicities. The selective sodium-glucose cotransporter 2 inhibitor, dapagliflozin, is a globally prescribed antihyperglycemic drug. Although dapagliflozin is usually administered once a day, the specific intake time is generally not mentioned. Therefore, this study aimed at investigating the diurnal effects of dapagliflozin on high-fat diet (HFD)-induced obesity in mice. Five-week-old male C57BL/6J mice were fed a normal (control) diet or HFD for 10 weeks. During the last 2 weeks, the mice were administered olive oil/ethanol emulsion or dapagliflozin (1mg/kg, p.o.) in the light or dark phase. At the end of the experiment, the mice were euthanized after an 18h fasting period, and plasma and tissue samples (epididymal white adipose tissues, liver, and kidney) were collected. Dapagliflozin administration in the light phase significantly decreased plasma glucose levels, insulin levels, adipose adipokines, and decreased the size of adipocytes, compared with the HFD group. In contrast, these parameters remained unchanged in the mice treated during the dark phase. Our data therefore suggests that dapagliflozin portrays definite chronopharmacology, which may provide valuable information on the importance of drug administration timing for maximal pharmacological effects.

19.
Am J Ophthalmol ; 207: 343-350, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31415735

RESUMO

PURPOSE: To determine whether the development of nonarteritic anterior ischemic optic neuropathy (NAION) is increased after receiving cataract surgery in a large general population. DESIGN: Nationwide, population-based, retrospective cohort study. METHODS: Setting: A 12-year nationwide, population-based, retrospective cohort study including 1,025,340 beneficiaries in the 2002-2013 Korean National Health Insurance Service database. PATIENTS: We identified 40,356 patients who had undergone cataract surgery and matched non-cataract surgery controls (1:2) using estimated propensity scores in reference to age, sex, demographics, comorbidities, and co-medications. OBSERVATIONS: Kaplan-Meier curves and Cox proportional hazard models were generated to determine the risk of developing NAION in the cataract surgery group compared to the non-cataract surgery group. MAIN OUTCOME MEASURES: Effect (hazard ratio [HR]) of cataract surgery on NAION development. RESULTS: The 10-year incidence probability of NAION was 0.70% (95% confidence interval [CI], 0.55%-0.86%) in the cataract surgery group and 0.27% (95% CI, 0.25%-0.29%) in the non-cataract surgery group (P < .0001, log-rank test). The cataract surgery group had an increased risk of developing NAION compared to the non-cataract surgery group (HR = 1.80; 95% CIs, 1.46-2.21) even after adjusting for demographics, comorbidities, Charlson comorbidity index, and co-medications. CONCLUSION: Our results suggest that patients undergoing cataract surgery have an increased risk of NAION.

20.
Anal Chem ; 91(14): 9246-9250, 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31265245

RESUMO

γ-Glutamyltransferase (GGT) plays a role in cleaving the γ-glutamyl bond of glutathione. The GGT is known to be overexpressed in some tumors and has been recognized as a potential biomarker for malignant tumors. Colon cancer is one of the most common cancers worldwide; however, there is no quantitative method for detecting cancer cells in human colon tissues. In this study, we report a ratiometric two-photon probe for GGT that can be applied in human colon tissues. The probe (Probe 2) showed high fluorescence efficiency, marked fluorescence changes, excellent kinetics, and selectivity for the GGT in live colon cells. Additionally, we obtained ratiometric two-photon microscopy images of GGT activity in human colon tissue. We used this method to compare normal and cancer tissues based on their ratio values; the ratio value was higher in cancer tissue than in normal tissue. This study provides a method for quantitative analysis of GGT, particularly in human colon cancer, which will be useful for studying GGT-related diseases and diagnosing colon cancer.

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