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1.
Mar Pollut Bull ; 197: 115791, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37992542

RESUMEN

We examined long-term response (2008-2017) of the macrobenthos to the Hebei Spirit oil spill that occurred around the Taean coast, Korea, in December 2007. Oil concentrations were below the Korea/US environmental standards as of January 2008. Organic matter, chlorophyll-a, and zooplankton abundance dominated by Noctiluca scintillans were higher after the spill. Macrobenthic diversity recovered to pre-incident (2007) level in 2011. Biomass exceeded that level in 2011 and the increase prolonged for 5 years. Cross-correlation and regression analyses showed that chlorophyll-a at year t and zooplankton abundance at t-2 had a significant relationship with macrobenthic biomass at t (p < 0.05 for both), suggesting the transfer of increased organic matter (transformed from crude oil within the pelagic ecosystem) into the benthic ecosystem. Coastal wetlands around the incident area, vulnerable to oil pollution and slowly remobilizing accumulated oil, seemed to affect pelagic ecosystem processes and the unexpectedly increased and sustained biomass.


Asunto(s)
Contaminación por Petróleo , Petróleo , Contaminación por Petróleo/análisis , Ecosistema , Estudios Longitudinales , Corea (Geográfico) , Clorofila/análisis , Clorofila A/análisis , Petróleo/análisis , República de Corea
2.
Diagnostics (Basel) ; 11(11)2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34829324

RESUMEN

We compared the accuracy of prediction of the response to neoadjuvant chemotherapy (NAC) in osteosarcoma patients between machine learning approaches of whole tumor utilizing fluorine-18fluorodeoxyglucose (18F-FDG) uptake heterogeneity features and a convolutional neural network of the intratumor image region. In 105 patients with osteosarcoma, 18F-FDG positron emission tomography/computed tomography (PET/CT) images were acquired before (baseline PET0) and after NAC (PET1). Patients were divided into responders and non-responders about neoadjuvant chemotherapy. Quantitative 18F-FDG heterogeneity features were calculated using LIFEX version 4.0. Receiver operating characteristic (ROC) curve analysis of 18F-FDG uptake heterogeneity features was used to predict the response to NAC. Machine learning algorithms and 2-dimensional convolutional neural network (2D CNN) deep learning networks were estimated for predicting NAC response with the baseline PET0 images of the 105 patients. ML was performed using the entire tumor image. The accuracy of the 2D CNN prediction model was evaluated using total tumor slices, the center 20 slices, the center 10 slices, and center slice. A total number of 80 patients was used for k-fold validation by five groups with 16 patients. The CNN network test accuracy estimation was performed using 25 patients. The areas under the ROC curves (AUCs) for baseline PET maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), metabolic tumor volume (MTV), and gray level size zone matrix (GLSZM) were 0.532, 0.507, 0.510, and 0.626, respectively. The texture features test accuracy of machine learning by random forest and support vector machine were 0.55 and 0. 54, respectively. The k-fold validation accuracy and validation accuracy were 0.968 ± 0.01 and 0.610 ± 0.04, respectively. The test accuracy of total tumor slices, the center 20 slices, center 10 slices, and center slices were 0.625, 0.616, 0.628, and 0.760, respectively. The prediction model for NAC response with baseline PET0 texture features machine learning estimated a poor outcome, but the 2D CNN network using 18F-FDG baseline PET0 images could predict the treatment response before prior chemotherapy in osteosarcoma. Additionally, using the 2D CNN prediction model using a tumor center slice of 18F-FDG PET images before NAC can help decide whether to perform NAC to treat osteosarcoma patients.

3.
Contrast Media Mol Imaging ; 2019: 3515080, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31427908

RESUMEN

Purpose: Patients with high-grade osteosarcoma undergo several chemotherapy cycles before surgical intervention. Response to chemotherapy, however, is affected by intratumor heterogeneity. In this study, we assessed the ability of a machine learning approach using baseline 18F-fluorodeoxyglucose (18F-FDG) positron emitted tomography (PET) textural features to predict response to chemotherapy in osteosarcoma patients. Materials and Methods: This study included 70 osteosarcoma patients who received neoadjuvant chemotherapy. Quantitative characteristics of the tumors were evaluated by standard uptake value (SUV), total lesion glycolysis (TLG), and metabolic tumor volume (MTV). Tumor heterogeneity was evaluated using textural analysis of 18F-FDG PET scan images. Assessments were performed at baseline and after chemotherapy using 18F-FDG PET; 18F-FDG textural features were evaluated using the Chang-Gung Image Texture Analysis toolbox. To predict the chemotherapy response, several features were chosen using the principal component analysis (PCA) feature selection method. Machine learning was performed using linear support vector machine (SVM), random forest, and gradient boost methods. The ability to predict chemotherapy response was evaluated using the area under the receiver operating characteristic curve (AUC). Results: AUCs of the baseline 18F-FDG features SUVmax, TLG, MTV, 1st entropy, and gray level co-occurrence matrix entropy were 0.553, 0538, 0.536, 0.538, and 0.543, respectively. However, AUCs of the machine learning features linear SVM, random forest, and gradient boost were 0.72, 0.78, and 0.82, respectively. Conclusion: We found that a machine learning approach based on 18F-FDG textural features could predict the chemotherapy response using baseline PET images. This early prediction of the chemotherapy response may aid in determining treatment plans for osteosarcoma patients.


Asunto(s)
Aprendizaje Automático , Osteosarcoma/tratamiento farmacológico , Tomografía de Emisión de Positrones/métodos , Análisis de Componente Principal , Área Bajo la Curva , Monitoreo de Drogas/métodos , Fluorodesoxiglucosa F18 , Humanos , Valor Predictivo de las Pruebas , Máquina de Vectores de Soporte
4.
Mar Pollut Bull ; 119(1): 359-364, 2017 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-28454761

RESUMEN

We bio-monitored the stress of oyster, Crassostrea gigas, for possible long term effects of thermal waste from a power plant. The expression level of its heat shock proteins (HSPs) was measured by real time-reverse transcript PCR along with their density and growth in the field. Oyster size varied in a distance dependent pattern. Physics modeling for evaluation of spreading of the thermal effluent revealed that station A is affected by the thermal effluents abundance, and the size of C. gigas showed a negative relationship with distance to the power plant. The abundance and size of C. gigas were smallest at station A, which was closest to the thermal effluent outlet. The kinetics of changes in the hsp70 and hsp90 mRNA levels in the mantle of C. gigas were also investigated. Regardless of the higher expression level of hsp70 mRNA than hsp90, both hsp70 and hsp90 mRNA levels were significantly higher at station A. The expression levels decreased inversely with distance from the thermal effluent outlet, with expression of hsp70 mRNA at station A being approximately 7-fold higher than at station B and 15-fold higher than at station C. Similarly, expression of hsp90 mRNA at station A was approximately 14-fold higher than at station B and 22-fold higher than at station C. The present findings provide new insights on biological correlation among the growth of individuals and population size and the molecular index in C. gigas following thermal effects.


Asunto(s)
Crassostrea , Monitoreo del Ambiente/métodos , Proteínas de Choque Térmico/metabolismo , Temperatura , Animales , Proteínas HSP70 de Choque Térmico , ARN Mensajero , Estrés Fisiológico
5.
Ann Nucl Med ; 29(2): 157-63, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25358843

RESUMEN

OBJECTIVE: The aim of this study was to evaluate the potential usefulness of (18)F-FDG PET/CT for detecting colorectal carcinoma and adenoma in asymptomatic adults. METHODS: 614 subjects were enrolled in this retrospective study. They underwent both (18)F-FDG PET/CT and colonoscopy in the same day as part of a cancer-screening program. Small focal FDG accumulation along the colorectum on (18)F-FDG PET/CT images were compared with colonoscopy findings. Size of lesion was measured on colonoscopy and histology was determined by biopsy or polypectomy. RESULTS: In 614 (18)F-FDG PET/CT images, 27 foci of FDG uptakes were observed in the colorectal area in 25 subjects. The overall sensitivity and specificity of (18)F-FDG PET/CT were 5.6 and 96.8 %, respectively, but sensitivity to detect lesions larger than or equal to 1 cm was 25.8 %. On the ROC analysis, the optimal cut-off value for differentiating premalignant and malignant lesions from other benign conditions was 5.0 (sensitivity = 50 %, specificity = 88 %, AUC = 0.643). CONCLUSIONS: Colonoscopic evaluation could be recommended by presence of focal colonic FDG uptake on (18)F-FDG PET/CT, especially when SUVmax is over 5.


Asunto(s)
Adenoma/diagnóstico , Enfermedades Asintomáticas , Neoplasias Colorrectales/diagnóstico , Fluorodesoxiglucosa F18 , Imagen Multimodal , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Adenoma/diagnóstico por imagen , Neoplasias Colorrectales/diagnóstico por imagen , Endoscopía Gastrointestinal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Curva ROC , Estudios Retrospectivos
6.
Fish Physiol Biochem ; 40(1): 205-19, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23907526

RESUMEN

This study aimed to better understand the hydromineral regulatory response of the anadromous river pufferfish, Takifugu obscurus, to salinity changes through real-time RT-PCR. After abrupt transfer from 30 or 5 psu to 5 or 30 psu, respectively, we analyzed the mRNA expression of Na⁺/K⁺ ATPase, prolactin receptor, and aquaporin from osmoregulatory organs of the river pufferfish such as gills, kidney, and intestine. Na⁺/K⁺ ATPase showed notable changes in the gills and kidney when salinity was increased. In the gills, the expression level of Na⁺/K⁺ ATPase suddenly increased within a day after abrupt transfer from 5 to 30 psu and then slightly declined within 2 days after exposure. In the kidney, Na⁺/K⁺ ATPase has shown consistently high mRNA expression after the increase in salinity. Expression levels of the prolactin receptor gene increased when environmental salinity decreased. In the intestine, gene expression of the prolactin receptor remained high, even when salinity decreased. To the contrary, there was a steady increase or decrease in mRNA expression in the kidney in response to salinity decrease or increase, respectively. As for aquaporins, aquaporin 1 was mainly expressed in the intestine and kidney, and aquaporin 3 was mainly expressed in the gills and intestine. In the gills, increased expression of aquaporin 3 was found after transfer to lower salinity and in the intestine and kidney, a decrease in salinity followed by an abrupt decrease in aquaporin 1 and aquaporin 3. Contrastingly, the expression of these genes increased in the intestine after transfer to 30 psu. Osmoregulatory genes were expressed in diverse organs, apparently to overcome an influx or exhaust of water or ions. A superior adaptation ability of the river pufferfish to a wide range of salinities is most reasonably due to active osmoregulatory processes mediated by the genes monitored here.


Asunto(s)
Regulación de la Expresión Génica , Osmorregulación , Salinidad , Tetraodontiformes/metabolismo , Animales , Acuaporinas/metabolismo , Receptores de Prolactina/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo
7.
Nucl Med Biol ; 39(7): 977-81, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22483845

RESUMEN

PURPOSE: The purpose of this prospective study was to clarify the value of FLT PET and FET PET for the noninvasive grading and prognosis of newly diagnosed gliomas. MATERIALS AND METHODS: Twenty patients with newly diagnosed gliomas were investigated with FLT and FET PET before surgery. FLT and FET uptakes were assessed by the maximum standardized uptake (SUVmax) of tumor, and the ratio to uptake in the normal brain parenchyma (TNR). All tumors were graded by WHO system. RESULTS: FLT PET detected all 17 high-grade gliomas (HGG) and did not detect all 3 low-grade gliomas (LGG). FET PET detected all 20 HGG and LGG regardless of grading. The average FLT SUVmax in HGG and LGG was 1.51 ± 0.72 and 0.30 ± 0.07, and the average FLT TNR in HGG and LGG was 5.52 ± 3.09 and 1.12 ± 0.14, respectively. The differences of FLT SUVmax and TNR between HGG and LGG were statistically significant (p=0.0069, p=0.0070). The average FET SUVmax in HGG and LGG was 2.68 ± 0.86 and 1.36 ± 0.15, and the average FET TNR in HGG and LGG was 2.31 ± 0.73 and 1.27 ± 0.12, respectively. The differences of FET SUVmax and TNR between HGG and LGG were statistically significant (p=0.0129, p=0.0095). CONCLUSIONS: FET PET has higher sensitivity in detection of gliomas rather than FLT PET, but it seems that FLT PET is better than FET PET for noninvasive grading and predicting prognosis of newly diagnosed gliomas, considering high contrast of FLT and overlap of FET uptakes between HGG and LGG.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Didesoxinucleósidos , Glioma/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Tirosina/análogos & derivados , Adulto , Anciano , Neoplasias Encefálicas/patología , Femenino , Glioma/patología , Humanos , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Pronóstico , Estudios Prospectivos
8.
Nucl Med Mol Imaging ; 44(1): 45-54, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24899937

RESUMEN

PURPOSE: The purpose of this study was to compare the uptakes and diagnostic accuracies between 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) and O-(2-[(18)F]fluoroethyl)-L-tyrosine (FET) PET in patients with a clinical suspicion of having a recurrence of glioma after multimodality treatment. METHODS: Thirty-two patients who underwent FLT and FET PET due to abnormal enhancement on magnetic resonance (MR) images were included. According to surgical confirmation or follow-up results, patients were divided into those with therapy-related benign changes (TRBCs) and those with recurrence. Recurrences were divided again into initial low-grade glioma (LGG) and high-grade glioma (HGG). The uptakes of FLT and FET were compared with the maximum standardized uptake value (SUVmax) and lesion-to-normal ratio (LNR). The diagnostic accuracies were compared via a receiver-operating-characteristic (ROC) curve analysis. RESULTS: The LNRs of FLT in recurrences with initial HGG (8.26 ± 5.02) were significantly higher than those in recurrences with initial LGG (3.43 ± 2.14) and TRBC (1.81 ± 0.60). The LNRs of FET in recurrence with initial HGG (2.70 ± 0.48) and LGG (3.03 ± 1.32) were significantly higher than those in the TRBC (1.60 ± 0.47). The areas under the ROC curve (AUCs) of FLT and FET for initial LGG were 0.768 and 0.893, respectively. The AUCs of FLT and FET for initial HGG were 1.000 and 0.964. However, there were no statistical significances. The results for comparing with SUVmax were the same as those with LNR. CONCLUSIONS: Uptakes of FLT were different according to initial grade in patients with recurrent glioma, but those of FET were not. However, there were no statistical significances in the diagnostic accuracies according to initial grade between the two tracers in this study.

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