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1.
Rev. bras. med. esporte ; 27(4): 381-385, Aug. 2021. tab, graf
Article in English | LILACS | ID: biblio-1288606

ABSTRACT

ABSTRACT Background: Objective: The study of sports biomechanics in sports medicine usually requires a special image analysis system (software) to obtain 3D kinematics data. Taking the swimming project in sports medicine as an example, 3D water images in water have always been relatively complicated and difficult. As light travels in different media, it will refract and reflect. When testing underwater movements, if only a land camera or an underwater camera is used for testing, the error caused by light refraction will be larger, which will affect the accuracy of the test data even more. Methods: Taking breaststroke movement as an example, a three-dimensional measurement method based on the Kwon3D movement analysis system is introduced. This method is different from the simple underwater camera test. It is a three-dimensional test method combining a land camera and an underwater camera. Two underwater cameras and two land cameras were used to simultaneously calibrate the water and underwater space with the same calibration frame in the experiment after analyzing and verifying the accuracy of 3D reconstruction. Results: The comprehensive reconstruction error is small, and the average relative error is less than 1%. Conclusions: The application of three-dimensional image analysis technology of vision systems in sports medicine is reasonable and worth promoting. Level of evidence II; Therapeutic studies - investigation of treatment results.


RESUMO Antecedente: Objetivo: O estudo da biomecânica do esporte na medicina esportiva geralmente requer o uso de um sistema especial de análise de imagens (software) para a obtenção de dados cinemáticos 3D. Tomando o projeto de natação na medicina esportiva como exemplo, a análise de imagens 3D da água na água sempre foi um teste relativamente complicado e difícil. À medida que a luz viaja em diferentes meios, ela refratará e refletirá. Ao testar movimentos subaquáticos, se apenas uma câmera terrestre ou subaquática for usada para o teste, o erro causado pela refração da luz será maior, o que afetará a precisão dos dados de teste ainda mais. Métodos: Tomando o movimento de nado peito como exemplo, um método de medição tridimensional baseado no sistema de análise de movimento Kwon3D é introduzido. Este método é diferente do teste simples de câmera subaquática. É um método de teste tridimensional que combina uma câmera terrestre e uma câmera subaquática. No experimento, duas câmeras subaquáticas e duas câmeras terrestres foram usadas para calibrar simultaneamente a água e o espaço subaquático com o mesmo quadro de calibração. Depois de analisar e verificar a precisão da reconstrução 3D. Resultados: O erro de reconstrução abrangente é pequeno e o erro relativo médio é inferior a 1% Conclusões: A aplicação da tecnologia de análise de imagem tridimensional do sistema de visão na medicina esportiva é razoável e vale a pena promover. Nível de evidência II; Estudos terapêuticos- investigação dos resultados do tratamento.


RESUMEN Antecedente: Objetivo: El estudio de la biomecánica del deporte en la medicina deportiva generalmente requiere el uso de un sistema de análisis de imágenes especial (software) para obtener datos de cinemática 3D. Tomando como ejemplo el proyecto de natación en medicina deportiva, el análisis de imágenes de agua en 3D en el agua siempre ha sido una prueba relativamente complicada y difícil. A medida que la luz viaja en diferentes medios, se refractará y reflejará. Al probar los movimientos bajo el agua, si solo se utiliza una cámara terrestre o una cámara submarina para realizar la prueba, el error causado por la refracción de la luz será mayor, lo que afectará aún más la precisión de los datos de la prueba. Métodos: tomando como ejemplo el movimiento de la brazada, se introduce un método de medición tridimensional basado en el sistema de análisis de movimiento Kwon3D. Este método es diferente de la simple prueba de cámara subacuática. Es un método de prueba tridimensional que combina una cámara terrestre y una cámara submarina. En el experimento, se utilizaron dos cámaras submarinas y dos cámaras terrestres para calibrar simultáneamente el agua y el espacio submarino con el mismo marco de calibración. Después de analizar y verificar la precisión de la reconstrucción 3D. Resultados: el error de reconstrucción integral es pequeño y el error relativo promedio es inferior al 1%. Conclusiones: La aplicación de la tecnología de análisis de imágenes tridimensionales del sistema de visión en la medicina deportiva es razonable y vale la pena promoverla. Nivel de evidencia II; Estudios terapéuticos- investigación de los resultados del tratamiento.


Subject(s)
Humans , Swimming/physiology , Video Recording/methods , Imaging, Three-Dimensional/methods , Biomechanical Phenomena/physiology , Algorithms , Calibration , Water
2.
Rev. Asoc. Odontol. Argent ; 109(1): 28-33, ene.-abr. 2021. tab
Article in Spanish | LILACS | ID: biblio-1280923

ABSTRACT

Objetivo: Describir una experiencia de capacitación de alumnos de grado en la evaluación radiográfica de tratamientos endodónticos realizados ex vivo. Material y métodos: Participaron un docente y 13 alumnos, cada uno de los cuales evaluó radiográficamente 100 tratamientos endodónticos realizados ex vivo para determinar si estos eran correctos o incorrectos. Posteriormente, el mismo docente, en una clase teórica, presentó a los alumnos otras imágenes radiográficas a fin de calibrar qué debería considerarse correcto o incorrecto. Luego fueron proyectadas nuevamente las radiografías de los 100 casos, y los alumnos efectuaron una nueva valoración. Para cada alumno, se determinó la frecuencia de concordancia con el docente en los 100 casos, antes y después de la calibración. Se categorizó cada observación como sin cambio, positiva (precalibración sin concordancia y poscalibración con concordancia) y negativa (precalibración con concordancia y poscalibración sin concordancia). En cada caso se calcularon la frecuencia para cada categoría, la frecuencia de concordancia entre cada alumno y el docente antes y después de la calibración, y la diferencia entre frecuencias. Resultados: La frecuencia absoluta de casos con concordancia alumno/docente sin cambios fue entre 65 y 85; con cambio positivo, entre 14 y 29; y con cambio negativo, entre 1 y 8. La concordancia antes y después de la calibración resultó entre 37% y 79,2%. Conclusión: La calibración mejoró parcialmente la capacitación de los alumnos para la evaluación radiográfica de los tratamientos endodónticos (AU)


Aim: To describe one experience of calibration in the radiographic evaluation of 100 endodontic treatments performed ex vivo in undergraduate students. Material and methods: One professor and 13 undergraduate students participated in this study, who independently radiographically evaluated 100 ex vivo endodontic treatments and determined whether each case was correct or incorrect. Later, the same professor presented a theoretical class to the students with other radiographic images in order to calibrate the difference between correct and incorrect treatments. Then the radiographs of the same 100 cases were projected and the students made a new evaluation. The frequency of agreement with the teacher was determined for each student in the 100 cases before and after the calibration. Each observation was categorized as without change, with positive change (pre-calibration without agreement and post-calibration with agreement) and with negative change (pre-calibration with agreement and post-calibration without agreement). The frequency for each category was calculated for each student. In each of the cases, the frequency of students in which concordances with the teacher were observed before and after calibration, and the difference between both frequencies were calculated. Results: The absolute frequency of cases with agreement of the students/teacher without changes varied between 65 and 85, with a positive change between 14 and 29 and a negative change between 1 and 8. The concordance before and after calibration varied between 37.0% and 79.2%. Conclusion: Calibration partially improved the training of students in radiographic evaluation of endodontic treatments (AU)


Subject(s)
Humans , Male , Female , Root Canal Therapy/statistics & numerical data , Education, Predental , Educational Measurement , Argentina , Schools, Dental , Students, Dental/psychology , Calibration , Radiography, Dental/methods , Tooth, Nonvital/diagnostic imaging , Faculty, Dental
3.
Article in Chinese | WPRIM | ID: wpr-879069

ABSTRACT

Spatial distribution uniformity is the critical quality attribute(CQA) of Ginkgo Leaves Tablets, a variety of big brand traditional Chinese medicine. The evaluation of the spatial distribution uniformity of active pharmaceutical ingredients(APIs) in Ginkgo Leaves Tablets is important in ensuring their stable and controllable quality. In this study, hyperspectral imaging technology was used to construct the spatial distribution map of API concentration based on three prediction models, further to realize the visualization research on the spatial distribution uniformity of Ginkgo Leaves Tablets. The region of interest(ROI) was selected from each Ginkgo Leaves Tablet, with length and width of 50 pixels, and a total of 2 500 pixels. Each pixel had 288 spectral channels, and the number of content prediction data could reach 1×10~5 for a single sample. The results of the three models showed that the Partial Least Squares(PLS) model had the highest prediction accuracy, with calibration set determination coefficient R_(pre)~2 of 0.987, prediction set determination coefficient R_(pre)~2 of 0.942, root mean square error of calibration(RMSEC) of 0.160%, and root mean square error of prediction(RMSEP) of 0.588%. The classical least-squares(CLS) model had a greater prediction error, with the RMSEP of 0.867%. Multivariate Curve Resolution-Alternating Least Square(MCR-ALS) model showed the worst predictive ability among the three models, and it couldn't realize content prediction. Based on the prediction results of PLS and CLS models, the spatial distribution map of APIs concentration was obtained through three-dimensional data reconstruction. Furthermore, histogram method was used to evaluate the spatial distribution uniformity of API. The data showed that the spatial distribution of APIs in Ginkgo Leaves Tablets was relatively uniform. The study explored the feasibility of visualization of spatial distribution of Ginkgo Leaves Tablets based on three models. The results showed that PLS model had the highest prediction accuracy, and MCR-ALS model had the lowest prediction accuracy. The research results could provide a new strategy for the visualization method of quality control of Ginkgo Leaves Tablets.


Subject(s)
Calibration , Ginkgo biloba , Least-Squares Analysis , Medicine, Chinese Traditional , Plant Leaves , Quality Control , Spectroscopy, Near-Infrared , Tablets
4.
Article in Chinese | WPRIM | ID: wpr-828899

ABSTRACT

To explore a method for calculating water equivalent diameter () based on localizer CT images for calculation of the size specific dose estimates (SSDE).GE Revolution CT and LightSpeed VCT were used to scan CT dose index phantoms 16 cm and 32 cm in diameter at the tube voltages of 80, 100 and 120 kV to obtain the axial image and anteroposterior localizer radiograph. According to the definition of CT Hounsfield unit, the axial images were used to calculate the conversion factors that convert the phantom thickness to water equivalent thickness. The gray value of the localizer radiograph and the water equivalent thickness were calibrated with a linear equation, and the parameters of the calibration were used to calculate the water equivalent thickness. The method was verified using 2 CT dose index phantoms and in 22 patients undergoing chest and abdominal CT examination.Comparison of the water equivalent diameter () based on the localizer radiograph and axial image of the 2 phantoms showed that the percentage difference between from the axial images and from the localizer radiograph was below 3%. The trend of variations with location in the two methods was sonsistent. The difference in in intermediate region of interest between the axial image and the localizer radiograph from the 22 patients was below 6.6%. With the mean in the ROI, the maximum percentage difference was 7.5%.Calibration of the gray value of the localizer radiograph and the water equivalent thickness using the axial image and localizer radiograph of CT dose index phantoms allows quick calculation of the SSDE based on the parameters of calibration.


Subject(s)
Calibration , Humans , Phantoms, Imaging , Radiation Dosage , Tomography, X-Ray Computed , Water
5.
Article in Chinese | WPRIM | ID: wpr-827973

ABSTRACT

A rapid analysis method based on ultraviolet-visual(UV-Vis) spectroscopy, near infrared(NIR) spectroscopy and multivariable data analysis was established for quality evaluation of Shengxuebao Mixture. The contents of eight active ingredients of Shengxuebao Mixture including albiflorin, paeoniflorin, 2, 3, 5, 4'-tetra-hydroxy-stilbene-2-O-β-D-glucopyranoside, specnuezhenide,ecliptasaponin D, emodin, calycosin-7-glucoside and astragaloside Ⅳ were simultaneously detected by using this method. HPLC-UV-MS was used as a reference method for determining the contents of these ingredients. Partial least squares(PLS) analysis was implemented as a linear method for multivariate models calibrated between UV spectrum/NIR spectrum and contents of 8 ingredients. Finally, the performance of the model was evaluated by 24 batches of test samples. The results showed that both UV-Vis and NIR models gave a good calibration ability with an R~2 value above 0.9, and the prediction ability was also satisfactory, with an R~2 value higher than 0.83 for UV-Vis model and higher than 0.79 for NIR model. The overall results demonstrate that the established method is accurate, robust and fast, therefore, it can be used for rapid quality evaluation of Shengxuebao Mixture.


Subject(s)
Calibration , Chromatography, High Pressure Liquid , Drugs, Chinese Herbal , Least-Squares Analysis , Mass Spectrometry , Spectroscopy, Near-Infrared
6.
Article in Chinese | WPRIM | ID: wpr-879211

ABSTRACT

Patient-specific volumetric modulated arc therapy (VMAT) quality assurance (QA) process is an important component of the implementation process of clinical radiotherapy. The tolerance limit and action limit of discrepancies between the calculated dose and the delivered radiation dose are the key parts of the VMAT QA processes as recognized by the AAPM TG-218 report, however, there is no unified standard for these two values among radiotherapy centers. In this study, based on the operational recommendations given in the AAPM TG-218 report, treatment site-specific tolerance limits and action limits of gamma pass rate in VMAT QA processes when using ArcCHECK for dose verification were established by statistical process control (SPC) methodology. The tolerance limit and action limit were calculated based on the first 25 in-control VMAT QA for each site. The individual control charts were drawn to continuously monitor the VMAT QA process with 287 VMAT plans and analyze the causes of VMAT QA out of control. The tolerance limits for brain, head and neck, abdomen and pelvic VMAT QA processes were 94.56%, 94.68%, 94.34%, and 92.97%, respectively, and the action limits were 93.82%, 92.54%, 93.23%, and 90.29%, respectively. Except for pelvic, the tolerance limits for the brain, head and neck, and abdomen were close to the universal tolerance limit of TG-218 (95%), and the action limits for all sites were higher than the universal action limit of TG-218 (90%). The out-of-control VMAT QAs were detected by the individual control chart, including one case of head and neck, two of the abdomen and two of the pelvic site. Four of them were affected by the setup error, and one was affected by the calibration of ArcCHECK. The results show that the SPC methodology can effectively monitor the IMRT/VMAT QA processes. Setting treatment site-specific tolerance limits is helpful to investigate the cause of out-of-control VMAT QA.


Subject(s)
Calibration , Humans , Quality Assurance, Health Care , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Radiotherapy, Intensity-Modulated
7.
Article in Chinese | WPRIM | ID: wpr-879208

ABSTRACT

In order to conduct surface monitoring of the three-dimensional spine morphology of the human body in daily life, a spine morphology measuring method using "single camera, multi-view" to construct stereo vision is proposed. The images of the back of the human body with landmarks of spinous process are captured from multiple angles by moving a single camera, and based on the "Zhang Zhengyou calibration method" and the triangulation principle of binocular stereo vision, the spatial conversion matrices corresponding to each other between all images and the 3D coordinates of the landmarks are calculated. Then the spine evaluation angle used to evaluate the spine morphology is further calculated. The tests' results showed that the spine evaluation angle error of this method is within ±3°, and the correlation between the results and the X-ray film Cobb angles is 0.871. The visual detection algorithm used in this paper is non-radioactive, and because only one camera is used in the measurement process and there is no need to pre-set the camera's shooting pose, the operation is simple. The research results of this article can be used in a mobile phone-based intelligent detection system, which will be suitable for the group survey of scoliosis in communities, schools, families and other occasions, as well as for the long-term follow-up of confirmed patients. This will provide a reference for doctors to diagnose the condition, predict the development trend of the condition, and formulate treatment plans.


Subject(s)
Algorithms , Calibration , Humans , Imaging, Three-Dimensional , Scoliosis/diagnostic imaging , Spine/diagnostic imaging , Technology
8.
Yonsei Medical Journal ; : 154-160, 2020.
Article in English | WPRIM | ID: wpr-782196

ABSTRACT

0.05). The area under the receiver operating characteristics curve (AUC) was 0.922 [95% confidence interval (CI) 0.89–0.95]. In external validation, the discrimination was good, with an AUC value of 0.833 (95% CI 0.70–0.92) for this model. Nomogram calibration plots indicated good agreement between the predicted and observed outcomes, exhibiting close approximation between the predicted and observed probability.CONCLUSION: We constructed a scoring model for predicting massive transfusion during cesarean section in women with placenta previa. This model may help in determining the need to prepare an appropriate amount of blood products and the optimal timing of blood transfusion.


Subject(s)
Area Under Curve , Blood Transfusion , Calibration , Cesarean Section , Cohort Studies , Discrimination, Psychological , Early Intervention, Educational , Erythrocytes , Female , Humans , Logistic Models , Maternal Age , Nomograms , Placenta Previa , Placenta , Placentation , Postpartum Hemorrhage , Pregnancy , ROC Curve , Ultrasonography
9.
Medicina (B.Aires) ; 79(6): 438-444, dic. 2019. ilus, graf, tab
Article in English | LILACS | ID: biblio-1056751

ABSTRACT

Cardiovascular disease (CVD) is the leading cause of death in Argentina. Computer simulation models allow to extrapolate evidence to broader populations than the originally studied, over longer timeframes, and to compare different subpopulations. The Cardiovascular Disease Policy Model (CVDPM) is a computer simulation state transition model used to represent and project future CVD mortality and morbidity in the population 35 years-old and older. The objective of this study was to update Argentina’s version of the CVDPM. For this purpose, information from the 2010 National Census, the 2013 National Risk Factor Survey, CESCAS I study, and PrEViSTA study were used to update the dynamics of population size, demographics, and CVD risk factor distributions over time. Model projections were later calibrated by comparing them to actual data on CVD events and mortality in the year 2010 (baseline year) in Argentina. Country statistics for people 35 years-old and older reported for 2010 a total of 41 219 myocardial infarctions (MIs), 58 658 strokes, and 281 710 total deaths. The CVDPM, in turn, predicted 41 265 MIs (difference: 0.11%), 58 584 strokes (difference: 0.13%), and 280 707 total deaths (difference: 0.36%) in the same population. In all cases, the final version of the model predicted the actual number of events with an accuracy superior to 99.5%, and could be used to forecast the changes in CVD incidence and mortality after the implementation of public policies.


La enfermedad cardiovascular (ECV) es la principal causa de muerte en Argentina. Los modelos de simulació;n por computadora permiten extrapolar evidencia a poblaciones más amplias que las originalmente estudiadas, a lo largo de períodos prolongados, y comparar diferentes subpoblaciones. El Cardiovascular Disease Policy Model (CVDPM, por sus siglas en ingló;©s) es un modelo de simulació;n utilizado para representar y proyectar la mortalidad y morbilidad por ECV en la població;n de 35 o más aó;±os. El objetivo de este trabajo fue actualizar la versió;n argentina del CVDPM. Para esto, se utilizó; informació;n del Censo Nacional 2010, la Encuesta Nacional de Factores de Riesgo 2013, el estudio CESCAS I, y el estudio PrEViSTA, para actualizar la dinámica del tamaó;±o de la població;n, sus características demográficas, y la distribució;n de factores de riesgo cardiovasculares a lo largo del tiempo. Las proyecciones del modelo se calibraron comparándolas con informació;n sobre eventos de ECV y mortalidad en el aó;±o 2010 (aó;±o de referencia) en Argentina. Las estadísticas argentinas informaron que en 2010 la població;n de 35 o más aó;±os sufrió; un total de 41 219 infartos de miocardio (IM), 58 658 accidentes cerebrovasculares y 281 710 muertes totales. El CVDPM predijo 41 265 IM (diferencia: 0.11%), 58 584 accidentes cerebrovasculares (diferencia: 0.13%) y 280 707 muertes totales (diferencia: 0.36%). En todos los casos, la versió;n final del modelo predijo el nó;ºmero real de eventos cardiovasculares con una precisió;n superior al 99.5%, pudiendo ser utilizado para pronosticar cambios en la incidencia y mortalidad de ECV debidos de la implementació;n de políticas pó;ºblicas.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Computer Simulation , Cardiovascular Diseases/mortality , Mortality/trends , Risk Assessment/methods , Argentina/epidemiology , Time Factors , Calibration , Sex Factors , Incidence , Reproducibility of Results , Risk Factors , Age Factors , Sex Distribution , Age Distribution , Forecasting
10.
Medicina (B.Aires) ; 79(6): 438-444, dic. 2019. ilus, graf, tab
Article in Spanish | LILACS | ID: biblio-1056750

ABSTRACT

La enfermedad cardiovascular (ECV) es la principal causa de muerte en Argentina. Los modelos de simulació;n por computadora permiten extrapolar evidencia a poblaciones más amplias que las originalmente estudiadas, a lo largo de períodos prolongados, y comparar diferentes subpoblaciones. El Cardiovascular Disease Policy Model (CVDPM, por sus siglas en ingló;©s) es un modelo de simulació;n utilizado para representar y proyectar la mortalidad y morbilidad por ECV en la població;n de 35 o más aó;±os. El objetivo de este trabajo fue actualizar la versió;n argentina del CVDPM. Para esto, se utilizó; informació;n del Censo Nacional 2010, la Encuesta Nacional de Factores de Riesgo 2013, el estudio CESCAS I, y el estudio PrEViSTA, para actualizar la dinámica del tamaó;±o de la població;n, sus características demográficas, y la distribució;n de factores de riesgo cardiovasculares a lo largo del tiempo. Las proyecciones del modelo se calibraron comparándolas con informació;n sobre eventos de ECV y mortalidad en el aó;±o 2010 (aó;±o de referencia) en Argentina. Las estadísticas argentinas informaron que en 2010 la població;n de 35 o más aó;±os sufrió; un total de 41 219 infartos de miocardio (IM), 58 658 accidentes cerebrovasculares y 281 710 muertes totales. El CVDPM predijo 41 265 IM (diferencia: 0.11%), 58 584 accidentes cerebrovasculares (diferencia: 0.13%) y 280 707 muertes totales (diferencia: 0.36%). En todos los casos, la versió;n final del modelo predijo el nó;ºmero real de eventos cardiovasculares con una precisió;n superior al 99.5%, pudiendo ser utilizado para pronosticar cambios en la incidencia y mortalidad de ECV debidos de la implementació;n de políticas pó;ºblicas.


Cardiovascular disease (CVD) is the leading cause of death in Argentina. Computer simulation models allow to extrapolate evidence to broader populations than the originally studied, over longer timeframes, and to compare different subpopulations. The Cardiovascular Disease Policy Model (CVDPM) is a computer simulation state transition model used to represent and project future CVD mortality and morbidity in the population 35 years-old and older. The objective of this study was to update Argentina’s version of the CVDPM. For this purpose, information from the 2010 National Census, the 2013 National Risk Factor Survey, CESCAS I study, and PrEViSTA study were used to update the dynamics of population size, demographics, and CVD risk factor distributions over time. Model projections were later calibrated by comparing them to actual data on CVD events and mortality in the year 2010 (baseline year) in Argentina. Country statistics for people 35 years-old and older reported for 2010 a total of 41 219 myocardial infarctions (MIs), 58 658 strokes, and 281 710 total deaths. The CVDPM, in turn, predicted 41 265 MIs (difference: 0.11%), 58 584 strokes (difference: 0.13%), and 280 707 total deaths (difference: 0.36%) in the same population. In all cases, the final version of the model predicted the actual number of events with an accuracy superior to 99.5%, and could be used to forecast the changes in CVD incidence and mortality after the implementation of public policies.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Computer Simulation , Cardiovascular Diseases/mortality , Mortality/trends , Risk Assessment/methods , Argentina/epidemiology , Time Factors , Calibration , Sex Factors , Incidence , Reproducibility of Results , Risk Factors , Age Factors , Sex Distribution , Age Distribution , Forecasting
11.
Rev. bras. anestesiol ; 69(3): 279-283, May-June 2019. tab, graf
Article in English | LILACS | ID: biblio-1013423

ABSTRACT

Abstract Background: Liver transplantation is the only curative therapeutic modality available for individuals at end-stage liver disease. There is no reliable method of predicting the early postoperative outcome of these patients. The Acute Physiology and Chronic Health Evaluation (APACHE) is a widely used model for predicting hospital survival and benchmarking in critically ill patients. This study evaluated the calibration and discrimination of APACHE IV in the postoperative period of elective liver transplantation in the southern Brazil. Methods: This was a clinical prospective and unicentric cohort study that included 371 adult patients in the immediate postoperative period of elective liver transplantation from January 1, 2012 to December 31, 2016. Results: In this study, liver transplant patients who evolved to hospital death had a significantly higher APACHE IV score (82.7 ± 5.1 vs. 51.0 ± 15.8; p < 0.001) and higher predicted mortality (6.5% [4.4-20.2%] vs. 2.3% [1.4-3.5%]; p < 0.001). The APACHE IV score showed an adequate calibration (Hosmer-Lemeshow - H-L = 11.37; p = 0.181) and good discrimination (Receiver Operator Curve - ROC of 0.797; Confidence Interval 95% - 95% CI 0.713-0.881; p < 0.0001), although Standardized Mortality Ratio (SMR = 2.63), (95% CI 1.66-4.27; p < 0.001) underestimate mortality. Conclusions: In summary, the APACHE IV score showed an acceptable performance for predicting a hospital outcome in the postoperative period of elective liver transplant recipients.


Resumo Introdução: O transplante de fígado é a única modalidade terapêutica curativa disponível para indivíduos com doença hepática terminal. Não há método confiável de prever o resultado pós-operatório imediato desses pacientes. A Avaliação da Gravidade da Doença Crônica e Aguda com bases Fisiológicas (APACHE) é um modelo amplamente usado para prever a sobrevida hospitalar e fazer a avaliação comparativa de pacientes criticamente enfermos. Este estudo avaliou a calibração e discriminação do APACHE IV no pós-operatório de transplante hepático eletivo no sul do Brasil. Métodos: Estudo clínico prospectivo de coorte em centro único que incluiu 371 pacientes adultos no pós-operatório imediato de transplante hepático eletivo de 1 de janeiro de 2012 a 31 de dezembro de 2016. Resultados: Neste estudo, pacientes com transplante hepático que evoluíram para óbito hospitalar obtiveram escore APACHE IV significativamente maior (82,7 ± 5,1 vs. 51,0 ± 15,8; p < 0,001) e mortalidade prevista mais alta (6,5% [4,4% -20,2%] vs 2,3% [1,4% -3,5%], p < 0,001). O escore APACHE IV mostrou uma calibração adequada (Hosmer-Lemeshow - H-L = 11,37; p = 0,181) e boa discriminação (Receiver Operator Curve - ROC de 0,797; intervalo de confiança de 95% - IC 95% 0,713-0,881; p < 0,0001), embora a taxa de mortalidade padronizada (Standardized Mortality Ratio - SMR = 2,63), (IC 95% 1,66-4,27; p < 0,001) subestime a mortalidade. Conclusões: Em resumo, o escore APACHE IV mostrou um desempenho aceitável para predizer um desfecho hospitalar no período pós-operatório de receptores eletivos de transplante hepático.


Subject(s)
Humans , Aged , Liver Transplantation/methods , APACHE , End Stage Liver Disease/surgery , Postoperative Period , Brazil , Calibration , Prospective Studies , Cohort Studies , Liver Transplantation/mortality , Hospital Mortality , End Stage Liver Disease/mortality , Middle Aged
12.
Neumol. pediátr. (En línea) ; 14(1): 41-51, abr. 2019. ilus, graf, tab
Article in Spanish | LILACS | ID: biblio-995742

ABSTRACT

Spirometry is the most commonly used test to evaluate lung function in children and adults. To obtain good quality results, several requirements must be fulfilled: professional capacity of the technician, the quality of the equipment, the patient's collaboration, the use of appropriate reference standards. The purpose of spirometry is to define types of ventilatory alterations of the central and peripheral airways, to evaluate the response to bronchodilators and to guide the presence of restrictive diseases. The new consensus of national and international experts are described, which have been perfecting several aspects of this test.


La espirometría es el examen más comúnmente utilizado para evaluar la función pulmonar en niños y adultos. Para obtener resultados de buena calidad deben cumplirse varios requisitos, desde la capacidad profesional del técnico, calidad de los equipos, colaboración del paciente y utilización de patrones de referencia adecuados. La espirometría tiene como utilidad definir alteraciones ventilatorias obstructivas de vía aérea central y periférica, evaluar respuesta a broncodilatador y orientar al diagnóstico de enfermedades restrictivas. Se describen los nuevos consensos de expertos nacionales e internacionales, los cuales han ido perfeccionando varios aspectos de este examen.


Subject(s)
Humans , Child , Adolescent , Respiratory Physiological Phenomena , Spirometry/standards , Lung Volume Measurements/instrumentation , Quality Control , Reference Values , Spirometry/instrumentation , Calibration , Vital Capacity/physiology , Forced Expiratory Volume/physiology , Maximal Expiratory Flow-Volume Curves , Lung/physiology
13.
Article in English | WPRIM | ID: wpr-719473

ABSTRACT

Cytogenetic dosimetry is useful for evaluating the absorbed dose of ionizing radiation based on analysis of radiation-induced chromosomal aberrations. We created two types of in vitro dose-response calibration curves for dicentric chromosomes (DC) and translocations (TR) induced by X-ray irradiation, using an electron linear accelerator, which is the most frequently used medical device in radiotherapy. We irradiated samples from four healthy Korean individuals and compared the resultant curves between individuals. Aberration yields were studied in a total of 31,800 and 31,725 metaphases for DC and TR, respectively, obtained from 11 X-ray irradiation dose-points (0, 0.05, 0.1, 0.25, 0.5, 0.75, 1, 2, 3, 4, and 5 Gy). The dose-response relationship followed a linear-quadratic equation, Y=C+αD+βD², with the coefficients C=0.0011 for DC and 0.0015 for TR, α=0.0119 for DC and 0.0048 for TR, and β=0.0617 for DC and 0.0237 for TR. Correlation coefficients between irradiation doses and chromosomal aberrations were 0.971 for DC and 0.6 for TR, indicating a very strong and a moderate correlation, respectively. This is the first study implementing cytogenetic dosimetry following exposure to ionizing X-radiation.


Subject(s)
Calibration , Chromosome Aberrations , Cytogenetics , In Vitro Techniques , Particle Accelerators , Radiation, Ionizing , Radiotherapy
14.
Article in English | WPRIM | ID: wpr-742424

ABSTRACT

Apixaban, an inhibitor of direct factor Xa, is used for the treatment of venous thromboembolic events or prevention of stroke. Unlike many other anticoagulant agents, it does not need periodic monitoring. However, monitoring is still required to determine the risk of bleeding due to overdose or surgery. Usually, apixaban concentrations are indirectly quantified using an anti-factor Xa assay. However, this method has a relatively narrow analytical concentration range, poor selectivity, and requires an external calibrator. Therefore, the goal of current study was to establish an analytical method for determining plasma levels of apixaban using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). To this end, apixaban was separated using 2.5 mM ammonium formate (pH 3.0) (A) and 100% methanol containing 0.1% formic acid (B) using the gradient method with a Thermo hypersil GOLD column. The mass detector condition was optimized using the electrospray ionization (ESI) positive mode for apixaban quantification. The developed method showed sufficient linearity (coefficient of determination [r² ≥ 0.997]) at calibration curve ranges. The percentage (%) changes in accuracy, precision, and all stability tests were within 15% of the nominal concentration. Apixaban concentration in plasma from healthy volunteers was quantified using the developed method. The mean maximum plasma concentration (C(max)) was 371.57 ng/mL, and the median time to achieve the C(max) (T(max)) was 4 h after administration of 10 mg apixaban alone. Although the results showed low extraction efficiency (~16%), the reproducibility (% change was within 15% of nominal concentration) was reliable. Therefore, the developed method could be used for clinical pharmacokinetic studies.


Subject(s)
Ammonium Compounds , Anticoagulants , Calibration , Chromatography, Liquid , Factor Xa , Healthy Volunteers , Hemorrhage , Humans , Mass Spectrometry , Methanol , Methods , Plasma , Stroke , Tandem Mass Spectrometry
15.
Gut and Liver ; : 669-682, 2019.
Article in English | WPRIM | ID: wpr-763883

ABSTRACT

BACKGROUND/AIMS: Microvascular invasion (MVI) is an established risk factor for hepatocellular carcinoma (HCC). However, prediction models that specifically focus on the individual prognoses of HCC patients with MVI is lacking. METHODS: A total of 385 HCC patients with MVI were randomly assigned to training and validation cohorts in a 2:1 ratio. The outcomes were disease-free survival (DFS) and overall survival (OS). Prognostic nomograms were established based on the results of multivariate analyses. The concordance index (C-index), calibration plots and Kaplan-Meier curves were employed to evaluate the accuracy, calibration and discriminatory ability of the models. RESULTS: The independent risk factors for both DFS and OS included age, tumor size, tumor number, the presence of gross vascular invasion, and the presence of Glisson's capsule invasion. The platelet-to-lymphocyte ratio was another risk factor for OS. On the basis of these predictors, two nomograms for DFS and OS were constructed. The C-index values of the nomograms for DFS and OS were 0.712 (95% confidence interval [CI], 0.679 to 0.745; p<0.001) and 0.698 (95% CI, 0.657 to 0.739; p<0.001), respectively, in the training cohort and 0.704 (95% CI, 0.650 to 0.708; p<0.001) and 0.673 (95% CI, 0.607 to 0.739; p<0.001), respectively, in the validation cohort. The calibration curves showed optimal agreement between the predicted and observed survival rates. The Kaplan-Meier curves suggested that these two nomograms had satisfactory discriminatory abilities. CONCLUSIONS: These novel predictive models have satisfactory accuracy and discriminatory abilities in predicting the prognosis of HCC patients with MVI after hepatectomy.


Subject(s)
Calibration , Carcinoma, Hepatocellular , Cohort Studies , Disease-Free Survival , Hepatectomy , Humans , Multivariate Analysis , Nomograms , Prognosis , Risk Factors , Survival Rate
16.
Article in English | WPRIM | ID: wpr-739658

ABSTRACT

Ceramide metabolism is known to be an essential etiology for various diseases, such as atopic dermatitis and Gaucher disease. Glucosylceramide synthase (GCS) is a key enzyme for the synthesis of glucosylceramide (GlcCer), which is a main ceramide metabolism pathway in mammalian cells. In this article, we developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to determine GCS activity using synthetic non-natural sphingolipid C8-ceramide as a substrate. The reaction products, C8-GlcCer for GCS, could be separated on a C18 column by reverse-phase high-performance liquid chromatography (HPLC). Quantification was conducted using the multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z 588.6 → 264.4 for C8-GlcCer at positive ionization mode. The calibration curve was established over the range of 0.625–160 ng/mL, and the correlation coefficient was larger than 0.999. This method was successfully applied to detect GCS in the human hepatocellular carcinoma cell line (HepG2 cells) and mouse peripheral blood mononuclear cells. We also evaluated the inhibition degree of a known GCS inhibitor 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) on GCS enzymatic activity and proved that this method could be successfully applied to GCS inhibitor screening of preventive and therapeutic drugs for ceramide metabolism diseases, such as atopic dermatitis and Gaucher disease.


Subject(s)
Animals , Calibration , Carcinoma, Hepatocellular , Cell Line , Chromatography, Liquid , Dermatitis, Atopic , Gaucher Disease , Humans , Mass Screening , Mass Spectrometry , Metabolism , Methods , Mice
17.
Article in English | WPRIM | ID: wpr-739582

ABSTRACT

PURPOSE: Many patients with cytology proven node-positive breast cancer receive a neoadjuvant chemotherapy (NAC) treatment. We developed a nomogram to predict the breast and axillary pathologic complete responses (pCR) in patients with a cytologically proven axillary node positive breast cancer with NAC. METHODS: We selected 995 patients who were diagnosed with an invasive breast cancer and axillary lymph nodes metastasis, and who were treated with NAC followed by a curative surgery at the Samsung Medical Center between January 2007 and December 2014. The baseline patient and tumor characteristics, chemotherapy regimen, and tumor and nodal responses were thoroughly analyzed and reviewed. A nomogram was developed using a binary logistic regression model with a cross validation. RESULTS: Axillary pCR was achieved in 47.3% and breast pCR was achieved in 24.3% of the patients after NAC. In this case, the both pCR was associated with an initial clinical tumor stage, negative progesterone receptor status, positive human epidermal growth factor receptor 2 status, and clinical radiologic nodal responses. A nomogram was developed based on the clinical and statistically significant predictors. It had good discrimination performance (area under the curve [AUC], 0.868; 95% confidence interval, 0.84–0.89) and calibration fit as noted in that case. The cross validation had an average AUC 0.853 (0.837–0.869). CONCLUSION: Our nomogram might help to predict breast and axillary pCRs after NAC in patients with an initially node-positive breast cancer. Minimal surgery might be acceptable in patients for whom the nomogram indicates a high probability of achieving pCRs.


Subject(s)
Area Under Curve , Breast Neoplasms , Breast , Calibration , Discrimination, Psychological , Drug Therapy , Humans , Logistic Models , Lymph Nodes , Neoadjuvant Therapy , Neoplasm Metastasis , Nomograms , Polymerase Chain Reaction , ErbB Receptors , Receptors, Progesterone
18.
Cancer Research and Treatment ; : 1275-1284, 2019.
Article in English | WPRIM | ID: wpr-763232

ABSTRACT

PURPOSE: Predicting lymph node metastasis (LNM) risk is crucial in determining further treatment strategies following endoscopic resection of T1 colorectal cancer (CRC). This study aimed to establish a new prediction model for the risk of LNM in T1 CRC patients. MATERIALS AND METHODS: The development set included 833 patients with T1 CRC who had undergone endoscopic (n=154) or surgical (n=679) resection at the National Cancer Center. The validation set included 722 T1 CRC patients who had undergone endoscopic (n=249) or surgical (n=473) resection at Daehang Hospital. A logistic regression model was used to construct the prediction model. To assess the performance of prediction model, discrimination was evaluated using the receiver operating characteristic (ROC) curves with area under the ROC curve (AUC), and calibration was assessed using the Hosmer-Lemeshow (HL) goodness-of-fit test. RESULTS: Five independent risk factors were determined in the multivariable model, including vascular invasion, high-grade histology, submucosal invasion, budding, and background adenoma. In final prediction model, the performance of the model was good that the AUC was 0.812 (95% confidence interval [CI], 0.770 to 0.855) and the HL chi-squared test statistic was 1.266 (p=0.737). In external validation, the performance was still good that the AUC was 0.771 (95% CI, 0.708 to 0.834) and the p-value of the HL chi-squared test was 0.040. We constructed the nomogram with the final prediction model. CONCLUSION: We presented an externally validated new prediction model for LNM risk in T1 CRC patients, guiding decision making in determining whether additional surgery is required after endoscopic resection of T1 CRC.


Subject(s)
Adenoma , Area Under Curve , Calibration , Colorectal Neoplasms , Decision Making , Discrimination, Psychological , Humans , Logistic Models , Lymph Nodes , Neoplasm Metastasis , Nomograms , Risk Factors , ROC Curve
19.
Cancer Research and Treatment ; : 1464-1478, 2019.
Article in English | WPRIM | ID: wpr-763214

ABSTRACT

PURPOSE: Hepatocellular carcinoma (HCC) is an aggressive disease with high recurrence rate. However, current staging systems were lack of predictive capacity for HCC recurrence. We aimed to develop prognostic nomograms based on inflammation-related markers for HCC patients underwent hepatectomy. MATERIALS AND METHODS: We recruited 889 surgically treated patients from two medical centers. Independent prognostic factors were identified by cox regression analyses. Nomograms for recurrence-free survival (RFS) and overall survival (OS) were established, and validated internally and externally. The performance, discrimination, and calibration of nomograms were assessed, and compared with existed staging systems. RESULTS: Neutrophil to lymphocyte ratio (NLR) and gamma-glutamyl transpeptidase to platelet ratio (GPR) were the two inflammation-related factor that independently correlated with survival. NLR, GPR, international normalized ratio (INR), microvascular invasion, satellite lesions, tumour number, tumour diameter, and macrovascular invasion were used to construct nomogram for RFS while GPR, total bilirubin, INR, α-fetoprotein, microvascular invasion, satellite lesions, tumour diameter, and macrovascular invasion were for OS. In the training cohort, the C-index of nomogram was 0.701 (95% confidence interval [CI], 0.669 to 0.732) for RFS and 0.761 (95% CI, 0.728 to 0.795) for OS. These results received both internal and external validation with C-index of 0.701 (95% CI, 0.647 to 0.755) and 0.707 (95% CI, 0.657 to 0.756) for RFS, and 0.706 (95% CI, 0.640 to 0.772) and 0.708 (95% CI, 0.646 to 0.771) for OS, respectively. The nomograms showed superior accuracy to conventional staging systems (p<0.001). CONCLUSION: The nomograms based on inflammation-related markers are of high efficacy in predicting survival of HCC patients after hepatectomy, which will be valuable in guiding postoperative interventions and follow-ups.


Subject(s)
Bilirubin , Blood Platelets , Calibration , Carcinoma, Hepatocellular , Cohort Studies , Discrimination, Psychological , Follow-Up Studies , gamma-Glutamyltransferase , Hepatectomy , Humans , Inflammation , International Normalized Ratio , Lymphocytes , Neutrophils , Nomograms , Recurrence
20.
Yonsei Medical Journal ; : 1028-1035, 2019.
Article in English | WPRIM | ID: wpr-762057

ABSTRACT

PURPOSE: To validate and update a nomogram for predicting ductal carcinoma in situ (DCIS) upstaging in preoperative biopsy. MATERIALS AND METHODS: Medical records of 444 preoperative DCIS patients were evaluated and used to validate a previous version of the Severance nomogram for predicting DCIS upstaging in preoperative biopsy. Patients were divided into two groups according to the final postoperative pathology. Univariate and multivariate analyses with the chi-square test, Student's t-test, and binary logistic regression method identified new significant variables. The updated nomogram was evaluated with the C-index and Hosmer—Lemeshow goodness of fit test. RESULTS: The area under a receiver operating characteristic curve for comparison with the previous nomogram was 0.48. In postoperative pathology, the pure DCIS and invasive cancer groups comprised 345 and 99 cases, respectively. Approximately 22.3% of patients preoperatively diagnosed with DCIS were upstaged to invasive cancer. Significant variables in the univariate analysis were operation type, human epidermal growth factor receptor 2 overexpression, comedo necrosis, sonographic mass, mammographic mass, preoperative biopsy method, and suspicious microinvasion in preoperative biopsy. In multivariate analysis, operation type, sonographic mass, mammographic mass, and suspicious microinvasion were risk factors for upstaging. The updated model with these variables showed moderate discrimination and was appropriate in the calibration test. CONCLUSION: The previous nomogram did not effectively discriminate upstaging of preoperative DCIS in an independent cohort. An updated version of the nomogram appears to provide more accurate information for predicting preoperative DCIS upstaging.


Subject(s)
Biopsy , Breast Neoplasms , Breast , Calibration , Carcinoma, Ductal , Carcinoma, Intraductal, Noninfiltrating , Cohort Studies , Discrimination, Psychological , Humans , Logistic Models , Medical Records , Methods , Multivariate Analysis , Necrosis , Nomograms , Pathology , ErbB Receptors , Risk Factors , ROC Curve , Ultrasonography
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