Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
J Rehabil Med ; 54: jrm00323, 2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-35925030

RESUMO

OBJECTIVE: To assess the effects of exoskeleton robot-assisted passive range of motion for induction training in combination with conventional hand rehabilitation in patients with chronic stroke. DESIGN: Single-cohort feasibility study. SUBJECTS: Chronic stroke with severe upper extremity hemiparesis. METHODS: Thirty sessions of therapy over a period of 10 weeks. Each session started with 30 min robot-assisted passive range of motion for the hand, followed by 30 min conventional hand rehabilitation. The Fugl-Meyer Assessment for upper extremity, arm subscore of Motricity Index, Functional Independence Measure and Fugl-Meyer assessment for sensation (Fugl-Meyer assessment-sensory) were conducted at pre-intervention (pre) and after the 16th (16-post) and 30th (30-post) sessions of interventions. RESULTS: Twelve patients with chronic stroke were recruited. The Fugl-Meyer assessment for upper extremity (16-post vs 30-post, p = 0.011), arm subscore of Motricity Index (pre vs 30-post, p = 0.012) and Functional Independence Measure (pre vs 30-post, p = 0.007; 16- post vs 30-post, p = 0.016) improved significantly after the therapy. However, FMA-sensory did not change significantly. CONCLUSION: Exoskeleton robot-assisted passive range of motion of the hand using an exoskeleton can be considered as an induction therapy before starting conventional therapy for hand rehabilitation in patients with chronic stroke. Further randomized control trials are needed to verify the therapeutic benefits.


Assuntos
Robótica , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Estudos de Viabilidade , Humanos , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Resultado do Tratamento , Extremidade Superior
2.
Med Biol Eng Comput ; 60(1): 151-169, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34783979

RESUMO

The Golgi apparatus and membrane tubules derived from this organelle play essential roles in membrane trafficking in eukaryotic cells. High-resolution live cell imaging is one highly suitable method for studying the molecular mechanisms of dynamics of organelles during membrane trafficking events. Due to the complex morphological changes and dynamic movements of the Golgi apparatus and associated membrane tubules during membrane trafficking, it is challenging to accurately quantify them. In this study, a semi-automated 2D tracking system, 2D-GolgiTrack, has been established for quantifying morphological changes and movements of Golgi elements, specifically encompassing the Golgi apparatus and its associated tubules, the fission and fusion of Golgi tubules, and the kinetics of formation of Golgi tubules and redistribution of the Golgi-associated protein Rab6A to the endoplasmic reticulum. The Golgi apparatus and associated tubules are segmented by a combination of Otsu's method and adaptive local normalization thresholding. Curvilinear skeletons and tips of skeletons of segmented tubules are used for calculating tubule length by the Geodesic method. The k-nearest neighbor is applied to search the possible candidate objects in the next frame and link the correct objects of adjacent frames by a tracking algorithm to calculate changes in morphological features of each Golgi object or tubule, e.g., number, length, shape, branch point and position, and fission or fusion events. Tracked objects are classified into morphological subtypes, and the Track-Map function of morphological evolution visualizes events of fission and fusion. Our 2D-GolgiTrack not only provides tracking results with 95% accuracy, but also maps morphological evolution for fast visual interpretation of the fission and fusion events. Our tracking system is able to characterize key morphological and dynamic features of the Golgi apparatus and associated tubules, enabling biologists to gain a greater understanding of the molecular mechanisms of membrane traffic involving this essential organelle. Graphical Abstract Overview of the semi-automated 2D tracking system. There are two main parts to the system, namely detection and tracking. The workflow process requires a raw sequence of images (a), which is filtered by the Gaussian filter method (c), and threshold intensity (b) to segment elements of Golgi cisternae (d) and tubules (e). Post-processing outputs are binary images of the cisternae area and tubule skeletons. The tubules are classified into three lengths, namely short, medium, and long tubules (f). Outputs of segmentation are calculated as morphological features (g). The tracking processing starts by loading the segmented outputs (h) and key-inputs of direction reference (i; (DR)) and interval setting of the start ((S)) and end ((E)) frame numbers (j). A tubule of interest is selected by the user (k; (GTinterest, S) as the tubule input ((GTIN)) at the current frame ((i = S)). The tracking algorithm tracks and links the correct tubules at each subsequent frame ((i = i + 1)). The locations of tubule tips are determined for detecting tubule branches using the (DR) to identify the direction of tubule growth (l: (1); (GTtipBr, i); Golgi cisternae: white area; Golgi tubule: white skeleton; tubule tips: green dots; branched tubules: two branches due to the (DR) of growth of the simulated tubule moving from left-to-right away from the Golgi cisternae location). According to the position of the (GTIN), five candidates ((GTcandidates, i)) are searched using the k-nearest neighbor method (l: (2)). Matching of tubules between the (GTIN) and those (GTcandidates, i) uses the bounding box technique to check the amount of tubule-overlap based on the tracking conditions (l: (3)). If there is tubule-overlap, the system collects that tubule as the final output ((GTOUT, i)). By contrast, shape (see the Extent feature in Table reftab:1) and distance features are used to generate the tracked output, which has a priority of a minimum of both of these features ((MinDIST, EXTENT)); otherwise, it is from the minimum of the distance ((MinDIST)). Once a loop of the interval track to the last frame is finished ((i = E + 1)), a Track-Map is generated allowing visualization of the morphological pattern of tubule formation and movement, including identification of fission and fusion events (m). Dynamic features are calculated (n). Related outputs are saved, and all features obtained from the detection and tracking processing are exported as MS Excel files (o).


Assuntos
Retículo Endoplasmático , Complexo de Golgi , Cinética , Movimento
3.
Biomed Eng Online ; 18(1): 26, 2019 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-30890177

RESUMO

BACKGROUND: Studies have shown that gait asymmetry and activity limitation can persist several months or years after ankle fracture. However, evidence of gait and trunk movement patterns following ankle fracture during the early rehabilitation period is scarce. Thus, we compared gait patterns and trunk movement during the early phase of rehabilitation between patients with ankle fracture and matched controls. METHODS: Ten patients with ankle fractures, and ten age- and sex-matched healthy controls were prospectively enrolled. An automated infrared-assisted, trunk accelerometer-based gait analysis system was used to measure walking speed, step length, and cadence. The median time of the evaluation following ankle fracture was 4.0 months. Trunk movement intensity was evaluated as acceleration root mean square. Trunk movement symmetry and regularity were analysed using the autocorrelation method. Differences in gait characteristics between the patient and control groups were analysed using the Mann-Whitney U test. Follow-up assessment of falls was performed 24 months after the fracture. The correlations between Lower Extremity Functional Scale (LEFS) scores/falls and gait parameters were evaluated using Spearman's rank correlation coefficient. RESULTS: Walking speed (p = 0.019), step length (p = 0.023), cadence (p = 0.003), and trunk movement intensity in anterior-posterior and vertical axis (p = 0.001, p = 0.003, respectively) were all significantly lower in the ankle fracture group than in the control group. Trunk movement symmetry in vertical direction (p = 0.019) decreased significantly in patients with ankle fractures, whereas between-strides regularity did not differ between groups. LEFS scores were moderately correlated with walking speed (r = 0.60, p = 0.044) and step length (r = 0.68, p = 0.021). During the 24 months after the fracture, 3 falls were reported by 3 patients. Trunk acceleration root mean square ratio in mediolateral axis (r = 0.72, p = 0.018) was highly correlated with future falls. CONCLUSION: During early rehabilitation, patients with ankle fracture may develop trunk movement asymmetry in the vertical direction accompanied with slower walking speed and cadence, and smaller step lengths, which can contribute to muscular imbalances and potential injury. Thus, proper rehabilitation strategies should be employed for these patients.


Assuntos
Fraturas do Tornozelo/fisiopatologia , Marcha , Tronco/fisiologia , Tronco/fisiopatologia , Acidentes por Quedas , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino
4.
Respir Care ; 62(12): 1557-1564, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28974646

RESUMO

BACKGROUND: According to Taiwan's integrated delivery system policy, ventilator-dependent patients are successfully liberated from mechanical ventilation in accordance with step-down care. However, premature discharge affects the 14-d readmission quality index. Therefore, we explored the risk and related factors of subjects liberated from mechanical ventilation who were re-intubated within 14 d. METHODS: This retrospective study analyzed a cohort of ventilator-dependent subjects 17 y of age and older using a population-based database from the Taiwan National Health Research Institutes Database from 2006 to 2010. Chi-square test and logistic regression analyses were used to explore whether subjects liberated from mechanical ventilation were re-intubated within 14 d and to investigate the related factors. RESULTS: A total of 15,840 ventilator-dependent subjects were liberated from mechanical ventilation, and 449 subjects were re-intubated within 14 d; the total re-intubation rate was 2.83%. The factors related to a higher risk of re-intubation were also the reasons for ventilator use, including complications, hospital accreditation level, and the ventilator weaning care stage. A higher risk of re-intubation was identified in subjects with COPD (odds ratio [OR] 1.32, 95% CI 1.02-1.7, P = .035) or pneumonia (OR 1.4, 95% CI 1.07-1.86, P = .02) and in subjects who stayed at a district hospital (OR 3.53, 95% CI 2.48-5.01, P < .001). Liberation from mechanical ventilation in the respiratory care ward and home respiratory care were associated with the highest risk of re-intubation, which was 2.32 times that of ICU subjects (P < .001). CONCLUSIONS: Factors associated with re-intubation within 14 d after ventilator liberation are related to the level and quality of the care setting; thus, to prevent re-intubation, more attention should be paid to higher-risk ventilator-dependent subjects after they are liberated from mechanical ventilation.


Assuntos
Intubação Intratraqueal/estatística & dados numéricos , Readmissão do Paciente/estatística & dados numéricos , Respiração Artificial/estatística & dados numéricos , Insuficiência Respiratória/terapia , Desmame do Respirador/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Bases de Dados Factuais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Qualidade da Assistência à Saúde , Respiração Artificial/métodos , Insuficiência Respiratória/etiologia , Estudos Retrospectivos , Fatores de Risco , Taiwan , Falha de Tratamento , Adulto Jovem
5.
BMC Cancer ; 16: 541, 2016 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-27464553

RESUMO

BACKGROUND: To evaluate whether infrared (IR) imaging findings are associated with prognosis in patients with invasive breast carcinomas. METHODS: This study was approved by the institutional review board of the research ethics committee of our hospital, and all participants gave written informed consent. From March 2005 to June 2007, we enrolled 143 patients with invasive breast cancer that underwent preoperative IR imaging. We used five IR signs to interpret breast IR imaging. Cox proportional hazards model was used to evaluate the effect of IR signs on long-term mortality. RESULTS: During a median follow-up of 2451 days (6.7 years), 31 patients died. Based on the Cox Proportional Hazards Model, IR1 sign (the temperature of cancer site minus that of the contralateral mirror imaging site) was positively associated with mortality in the univariate analysis (overall mortality hazard ratio [HR], 2.29; p = 0.03; disease-specific mortality HR, 2.57; p = 0.04) as well as the multivariate analysis after controlling for clinicopathological factors (overall mortality HR, 3.85; p = 0.01; disease-specific mortality HR, 3.91, p = 0.02). In patients with clinical stage I and II disease, IR1 was also positively associated with mortality (overall mortality HR, 3.76; p = 0.03; disease-specific mortality HR, 4.59; p = 0.03). Among patients with node-negative disease, IR1 and IR5 (asymmetrical thermographic pattern) were associated with mortality (p = 0.04 for both IR1 and IR5, chi-squared test). CONCLUSION: Breast IR findings are associated with mortality in patients with invasive breast carcinomas. The association remained in patients with node-negative disease. TRIAL REGISTRATION: NCT00166998 .


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/mortalidade , Termografia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Estudos de Coortes , Feminino , Humanos , Imageamento Tridimensional , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais
6.
Sensors (Basel) ; 16(8)2016 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-27455281

RESUMO

The aim of this study was to determine the test-retest reliability of an automated infrared-assisted, trunk accelerometer-based gait analysis system for measuring gait parameters of healthy subjects in a hospital. Thirty-five participants (28 of them females; age range, 23-79 years) performed a 5-m walk twice using an accelerometer-based gait analysis system with infrared assist. Measurements of spatiotemporal gait parameters (walking speed, step length, and cadence) and trunk control (gait symmetry, gait regularity, acceleration root mean square (RMS), and acceleration root mean square ratio (RMSR)) were recorded in two separate walking tests conducted 1 week apart. Relative and absolute test-retest reliability was determined by calculating the intra-class correlation coefficient (ICC3,1) and smallest detectable difference (SDD), respectively. The test-retest reliability was excellent for walking speed (ICC = 0.87, 95% confidence interval = 0.74-0.93, SDD = 13.4%), step length (ICC = 0.81, 95% confidence interval = 0.63-0.91, SDD = 12.2%), cadence (ICC = 0.81, 95% confidence interval = 0.63-0.91, SDD = 10.8%), and trunk control (step and stride regularity in anterior-posterior direction, acceleration RMS and acceleration RMSR in medial-lateral direction, and acceleration RMS and stride regularity in vertical direction). An automated infrared-assisted, trunk accelerometer-based gait analysis system is a reliable tool for measuring gait parameters in the hospital environment.


Assuntos
Acelerometria/métodos , Marcha/fisiologia , Monitorização Fisiológica/métodos , Caminhada/fisiologia , Acelerometria/instrumentação , Adulto , Idoso , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/instrumentação , Equilíbrio Postural/fisiologia
7.
Respir Care ; 60(12): 1786-95, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26443020

RESUMO

BACKGROUND: Readmission of mechanically ventilated patients to an ICU within 7 d reflects not only patient safety but also the quality of care of the ICU. This study aimed to investigate the risk and related factors for readmission to an ICU within 7 d in mechanically ventilated subjects. METHODS: A total of 658,452 mechanically ventilated subjects discharged from an ICU whose age was ≥ 17 y old were obtained from the Taiwan National Health Insurance Research Database for the period from January 1, 2005, to December 31, 2011. The study applied a generalized estimating equation logistic regression model to explore whether the mechanically ventilated subjects were readmitted within 7 d or not and the related factors. RESULTS: A total of 29,657 subjects were readmitted to the ICU within 7 d; the total readmission rate was 4.5%. Also, 64.8% of the subjects with the same diagnosis were returned to the ICU within 7 d. Generalized estimating equation logistic regression model results showed that the factors related to higher risk of readmission were male sex, old age, higher comorbidity score, complications (eg, pneumothorax, subcutaneous emphysema, pneumonia, oxygen toxicity, pulmonary embolism, or pulmonary edema), use of a private hospital ICU, ICU stay ≥21 d, transfer to a respiratory care center and respiratory care ward, and subsequent transfer to the regional hospital or district hospital. CONCLUSIONS: The risk and related factors of a mechanically ventilated subject whose age is ≥ 17 y old being readmitted to the ICU within 7 d include subject characteristics, health status, hospital attributes, and the length of ICU stay. Therefore, higher risk subjects should receive attention and assessment before transfer or discharge from the ICU to prevent readmission.


Assuntos
Unidades de Terapia Intensiva/estatística & dados numéricos , Readmissão do Paciente/estatística & dados numéricos , Respiração Artificial/efeitos adversos , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Humanos , Tempo de Internação , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Alta do Paciente/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Taiwan , Fatores de Tempo , Adulto Jovem
8.
Nat Methods ; 11(3): 281-9, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24441936

RESUMO

Particle tracking is of key importance for quantitative analysis of intracellular dynamic processes from time-lapse microscopy image data. Because manually detecting and following large numbers of individual particles is not feasible, automated computational methods have been developed for these tasks by many groups. Aiming to perform an objective comparison of methods, we gathered the community and organized an open competition in which participating teams applied their own methods independently to a commonly defined data set including diverse scenarios. Performance was assessed using commonly defined measures. Although no single method performed best across all scenarios, the results revealed clear differences between the various approaches, leading to notable practical conclusions for users and developers.


Assuntos
Interpretação de Imagem Assistida por Computador , Microscopia de Fluorescência/métodos , Interpretação de Imagem Assistida por Computador/normas , Microscopia de Fluorescência/normas
9.
Respir Care ; 58(4): 676-82, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23050858

RESUMO

OBJECTIVE: The integrated prospective payment program (IPP), which encourages the integrated care of mechanically ventilated patients in order to reduce the heavy utilization of high-cost ICUs, has been implemented by Taiwan's Bureau of National Health Insurance since July 2000. The aim of this study was to assess the impact of this program on weaning, hospital stay, mortality, and cost for patients requiring prolonged mechanical ventilation (PMV). METHODS: A data set of 1,000,000 randomly selected insurance holders from the National Health Research Insurance Database, Taiwan, was retrospectively analyzed. We enrolled 7,967 adult patients (age ≥ 17 y) who required PMV (duration ≥ 21 d) over a 6 year period. RESULTS: There were 3,275 patients on PMV before (1997-1999) and 4,692 patients on PMV after (2001-2003) the IPP implementation. After IPP implementation, PMV was found to be required in patients with a significantly higher age, lower urbanization level, higher income status, and a higher prevalence of neuromuscular disease (P < .001). In-hospital mortality was similar between the 2 periods (17.2% before vs 16.2% after, P = .26), but the weaning rate was significantly lower in the latter period (68.1% vs 64.2%, P < .001). Total hospital stay (75.3 d vs 95.1 d, P < .001) and duration of mechanical ventilation usage (55.8 d vs 71.6 d, P < .001) were both significantly higher after the IPP implementation. Total hospitalization cost in the PMV patients was significantly lower after IPP implementation. CONCLUSIONS: Implementation of the IPP program reduced the total hospitalization cost, increased the duration of mechanical ventilation usage and stay, and reduced the weaning rate in PMV patients.


Assuntos
Cuidados Críticos/organização & administração , Custos de Cuidados de Saúde , Sistema de Pagamento Prospectivo , Respiração Artificial , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Respiração Artificial/economia , Respiração Artificial/mortalidade , Respiração Artificial/estatística & dados numéricos , Estudos Retrospectivos , Fatores Socioeconômicos , Taiwan , Fatores de Tempo
10.
PLoS Comput Biol ; 7(10): e1002212, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21998575

RESUMO

Morphological dynamics of mitochondria is associated with key cellular processes related to aging and neuronal degenerative diseases, but the lack of standard quantification of mitochondrial morphology impedes systematic investigation. This paper presents an automated system for the quantification and classification of mitochondrial morphology. We discovered six morphological subtypes of mitochondria for objective quantification of mitochondrial morphology. These six subtypes are small globules, swollen globules, straight tubules, twisted tubules, branched tubules and loops. The subtyping was derived by applying consensus clustering to a huge collection of more than 200 thousand mitochondrial images extracted from 1422 micrographs of Chinese hamster ovary (CHO) cells treated with different drugs, and was validated by evidence of functional similarity reported in the literature. Quantitative statistics of subtype compositions in cells is useful for correlating drug response and mitochondrial dynamics. Combining the quantitative results with our biochemical studies about the effects of squamocin on CHO cells reveals new roles of Caspases in the regulatory mechanisms of mitochondrial dynamics. This system is not only of value to the mitochondrial field, but also applicable to the investigation of other subcellular organelle morphology.


Assuntos
Caspases/metabolismo , Mitocôndrias/enzimologia , Mitocôndrias/ultraestrutura , Animais , Células CHO , Inibidores de Caspase , Biologia Computacional , Cricetinae , Cricetulus , Inibidores de Cisteína Proteinase/farmacologia , Dimetil Sulfóxido/farmacologia , Furanos/farmacologia , Lactonas/farmacologia , Mitocôndrias/classificação , Mitocôndrias/efeitos dos fármacos , Modelos Biológicos , Oligopeptídeos/farmacologia , Reconhecimento Automatizado de Padrão/estatística & dados numéricos
11.
Acad Radiol ; 18(2): 212-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21126889

RESUMO

RATIONALE AND OBJECTIVES: Evidence on breast infrared (IR) imaging and its association with estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) statuses of breast cancers is limited. The aim of this study was to investigate the association of IR imaging findings and ER, PR, and HER2 status in breast cancers. MATERIALS AND METHODS: A total of 163 women with 171 pathologically proven breast cancers underwent IR imaging of the breast before surgery. Five IR signs were used to score the lesions: IR1, the temperature difference (ΔT) of the lesion site from that of the contralateral mirror image site; IR2, ΔT of the lesion site from that of the adjacent normal breast tissue in the same breast; IR3, abnormal vascular morphologic patterns; IR4, focal bulge or edge sign with back heat at the lesion site; and IR5, asymmetric thermographic pattern between the lesion site and the contralateral breast. The association of different IR signs with ER, PR, and HER2 status was evaluated using Fisher's exact test. RESULTS: IR1 was inversely associated with ER (P = .010) and PR status (P = .039). IR2 was inversely related to PR status (P = .020). IR5 was inversely associated with ER (P = .037) and PR (P = .022) status. No IR sign was associated with HER2 status. Triple-negative (ER-negative, PR-negative, and HER2-negative) cancers tended to show higher IR1 scores compared to other types of cancers (P = .029). CONCLUSION: Breast IR findings were associated with ER and PR status of breast cancers. Triple-negative cancers more frequently featured higher IR1 scores than other types of cancers.


Assuntos
Neoplasias da Mama/diagnóstico , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Termografia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/química , Feminino , Humanos , Pessoa de Meia-Idade
12.
Bioinformatics ; 26(12): i29-37, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20529919

RESUMO

MOTIVATION: High-throughput image-based assay technologies can rapidly produce a large number of cell images for drug screening, but data analysis is still a major bottleneck that limits their utility. Quantifying a wide variety of morphological differences observed in cell images under different drug influences is still a challenging task because the result can be highly sensitive to sampling and noise. RESULTS: We propose a graph-based approach to cell image analysis. We define graph transition energy to quantify morphological differences between image sets. A spectral graph theoretic regularization is applied to transform the feature space based on training examples of extremely different images to calibrate the quantification. Calibration is essential for a practical quantification method because we need to measure the confidence of the quantification. We applied our method to quantify the degree of partial fragmentation of mitochondria in collections of fluorescent cell images. We show that with transformation, the quantification can be more accurate and sensitive than that without transformation. We also show that our method outperforms competing methods, including neighbourhood component analysis and the multi-variate drug profiling method by Loo et al. We illustrate its utility with a study of Annonaceous acetogenins, a family of compounds with drug potential. Our result reveals that squamocin induces more fragmented mitochondria than muricin A. AVAILABILITY: Mitochondrial cell images, their corresponding feature sets (SSLF and WSLF) and the source code of our proposed method are available at http://aiia.iis.sinica.edu.tw/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Estruturas Celulares/ultraestrutura , Biologia Computacional/métodos , Acetogeninas/metabolismo , Calibragem , Interpretação de Imagem Assistida por Computador/métodos , Mitocôndrias/ultraestrutura
13.
Biomed Eng Online ; 9: 3, 2010 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-20055999

RESUMO

BACKGROUND: The study was conducted to investigate the diagnostic performance of infrared (IR) imaging of the breast using an interpretive model derived from a scoring system. METHODS: The study was approved by the Institutional Review Board of our hospital. A total of 276 women (mean age = 50.8 years, SD 11.8) with suspicious findings on mammograms or ultrasound received IR imaging of the breast before excisional biopsy. The interpreting radiologists scored the lesions using a scoring system that combines five IR signs. The ROC (receiver operating characteristic) curve and AUC (area under the ROC curve) were analyzed by the univariate logistic regression model for each IR sign and an age-adjusted multivariate logistic regression model including 5 IR signs. The cut-off values and corresponding sensitivity, specificity, Youden's Index (Index = sensitivity+specificity-1), positive predictive value (PPV), negative predictive value (NPV) were estimated from the age-adjusted multivariate model. The most optimal cut-off value was determined by the one with highest Youden's Index. RESULTS: For the univariate model, the AUC of the ROC curve from five IR signs ranged from 0.557 to 0.701, and the AUC of the ROC from the age-adjusted multivariate model was 0.828. From the ROC derived from the multivariate model, the sensitivity of the most optimal cut-off value would be 72.4% with the corresponding specificity 76.6% (Youden's Index = 0.49), PPV 81.3% and NPV 66.4%. CONCLUSIONS: We established an interpretive age-adjusted multivariate model for IR imaging of the breast. The cut-off values and the corresponding sensitivity and specificity can be inferred from the model in a subpopulation for diagnostic purpose. TRIAL REGISTRATION: NCT00166998.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/fisiopatologia , Mama/fisiopatologia , Interpretação de Imagem Assistida por Computador/métodos , Modelos Biológicos , Termografia/métodos , Temperatura Corporal , Simulação por Computador , Feminino , Humanos , Aumento da Imagem/métodos , Raios Infravermelhos , Pessoa de Meia-Idade , Análise Multivariada , Projetos Piloto , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
BMC Bioinformatics ; 10: 160, 2009 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-19473520

RESUMO

BACKGROUND: Internal ribosomal entry sites (IRESs) provide alternative, cap-independent translation initiation sites in eukaryotic cells. IRES elements are important factors in viral genomes and are also useful tools for bi-cistronic expression vectors. Most existing RNA structure prediction programs are unable to deal with IRES elements. RESULTS: We designed an IRES search system, named IRSS, to obtain better results for IRES prediction. RNA secondary structure prediction and comparison software programs were implemented to construct our two-stage strategy for the IRSS. Two software programs formed the backbone of IRSS: the RNAL fold program, used to predict local RNA secondary structures by minimum free energy method; and the RNA Align program, used to compare predicted structures. After complete viral genome database search, the IRSS have low error rate and up to 72.3% sensitivity in appropriated parameters. CONCLUSION: IRSS is freely available at this website http://140.135.61.9/ires/. In addition, all source codes, precompiled binaries, examples and documentations are downloadable for local execution. This new search approach for IRES elements will provide a useful research tool on IRES related studies.


Assuntos
Simulação por Computador , Internet , Conformação de Ácido Nucleico , RNA Mensageiro/química , RNA Viral/química , Análise de Sequência de RNA/métodos , Software , Sequência de Bases , Análise Discriminante , Genoma Viral , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Viral/genética , Alinhamento de Sequência , Termodinâmica , Interface Usuário-Computador
15.
Microsc Res Tech ; 72(9): 639-49, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19350659

RESUMO

Membrane trafficking is a very important physiological process involved in protein transport, endocytosis, and exocytosis. The functions of vesicles are strongly correlated with various spatial dynamic properties of vesicles, including their types of movements and morphology. Several methods are used to quantify such dynamic properties, but most of them are specific to particular populations of vesicles. We previously developed the so-called PTrack system for quantifying the dynamics of secretory vesicles near the cell surface, which are small and move slowly. To improve the system performance in quantifying large and fast-moving vesicles, we firstly combined morphological filter with two-threshold image processing techniques to locate granules of various sizes. Next, Kalman filtering was used to improve the performance in tracking fast-moving and large granules. Performance evaluation by using simulation image sequences shown that the new system, called PTrack II, yields better tracking accuracy. The tracking system was validated using time-lapse images of insulin granules in betaTC3 cells, which revealed that PTrack II could track better than PTrack, averaged accuracy up to 56%. The overall tracking results indicate that PTrack II is better at tracking vesicles with various dynamic properties, which will facilitate the acquisition of more-complete information on vesicle dynamics.


Assuntos
Microscopia de Fluorescência/instrumentação , Vesículas Secretórias/química , Animais , Linhagem Celular Tumoral , Processamento de Imagem Assistida por Computador , Insulina/metabolismo , Camundongos , Microscopia de Fluorescência/métodos , Transporte Proteico , Vesículas Secretórias/metabolismo
16.
Microsc Res Tech ; 71(4): 305-14, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18069668

RESUMO

Systemic analysis of subcellular protein localization (location proteomics) provides clues for understanding gene functions and physiological condition of the cells. However, recognition of cell images of subcellular structures highly depends on experience and becomes the rate-limiting step when classifying subcellular protein localization. Several research groups have extracted specific numerical features for the recognition of subcellular protein localization, but these recognition systems are restricted to images of single particular cell line acquired by one specific imaging system and not applied to recognize a range of cell image sources. In this study, we establish a single system for automated subcellular structure recognition to identify cell images from various sources. Two different sources of cell images, 317 Vero (http://gfp-cdna.embl.de) and 875 CHO cell images of subcellular structures, were used to train and test the system. When the system was trained by a single source of images, the recognition rate is high and specific to the trained source. The system trained by the CHO cell images gave high average recognition accuracy for CHO cells of 96%, but this was reduced to 46% with Vero images. When we trained the system using a mixture of CHO and Vero cell images, an average accuracy of recognition reached 86.6% for both CHO and Vero cell images. The system can reject images with low confidence and identify the cell images correctly recognized to avoid manual reconfirmation. In summary, we have established a single system that can recognize subcellular protein localizations from two different sources for location-proteomic studies. studies.


Assuntos
Microscopia de Fluorescência/métodos , Reconhecimento Automatizado de Padrão/métodos , Proteínas/metabolismo , Frações Subcelulares/classificação , Frações Subcelulares/ultraestrutura , Algoritmos , Animais , Células CHO , Chlorocebus aethiops , Cricetinae , Cricetulus , Proteínas de Fluorescência Verde/metabolismo , Interpretação de Imagem Assistida por Computador , Frações Subcelulares/metabolismo , Células Vero
17.
Bioinformatics ; 23(24): 3374-81, 2007 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-17956879

RESUMO

MOTIVATION: Determining locations of protein expression is essential to understand protein function. Advances in green fluorescence protein (GFP) fusion proteins and automated fluorescence microscopy allow for rapid acquisition of large collections of protein localization images. Recognition of these cell images requires an automated image analysis system. Approaches taken by previous work concentrated on designing a set of optimal features and then applying standard machine-learning algorithms. In fact, trends of recent advances in machine learning and computer vision can be applied to improve the performance. One trend is the advances in multiclass learning with error-correcting output codes (ECOC). Another trend is the use of a large number of weak detectors with boosting for detecting objects in images of real-world scenes. RESULTS: We take advantage of these advances to propose a new learning algorithm, AdaBoost.ERC, coupled with weak and strong detectors, to improve the performance of automatic recognition of protein subcellular locations in cell images. We prepared two image data sets of CHO and Vero cells and downloaded a HeLa cell image data set in the public domain to evaluate our new method. We show that AdaBoost.ERC outperforms other AdaBoost extensions. We demonstrate the benefit of weak detectors by showing significant performance improvements over classifiers using only strong detectors. We also empirically test our method's capability of generalizing to heterogeneous image collections. Compared with previous work, our method performs reasonably well for the HeLa cell images. AVAILABILITY: CHO and Vero cell images, their corresponding feature sets (SSLF and WSLF), our new learning algorithm, AdaBoost.ERC, and Supplementary Material are available at http://aiia.iis.sinica.edu.tw/


Assuntos
Algoritmos , Inteligência Artificial , Interpretação de Imagem Assistida por Computador/métodos , Microscopia de Fluorescência/métodos , Reconhecimento Automatizado de Padrão/métodos , Proteínas/metabolismo , Frações Subcelulares/metabolismo , Proteínas/ultraestrutura , Frações Subcelulares/ultraestrutura
18.
Microsc Res Tech ; 70(2): 119-34, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17146761

RESUMO

Recent technological improvements have made it possible to examine the dynamics of individual vesicles at a very high temporal and spatial resolution. Quantification of the dynamic properties of secretory vesicles is labor-intensive and therefore it is crucial to develop software to automate the process of analyzing vesicle dynamics. Dual-threshold and binary image conversion were applied to enhance images and define the areas of objects of interest that were to be tracked. The movements, changes in fluorescence intensity, and changes in the area of each tracked object were measured using a new software system named the Protein Tracking system (PTrack). Simulations revealed that the system accurately recognized tracked objects and measured their dynamic properties. Comparison of the results from tracking real time-lapsed images manually with those automatically obtained using PTrack revealed similar patterns for changes in fluorescence intensity and a high accuracy (<89%). According to tracking results, PTrack can distinguish different vesicular organelles that are similar in shape, based on their unique dynamic properties. In conclusion, the novel tracking system, PTrack, should facilitate automated quantification of the dynamic properties of vesicles that are important when classifying vesicular protein locations.


Assuntos
Exocitose/fisiologia , Vesículas Secretórias/fisiologia , Animais , Transporte Biológico Ativo , Proteínas de Fluorescência Verde/metabolismo , Processamento de Imagem Assistida por Computador , Microscopia de Fluorescência/instrumentação , Microscopia de Fluorescência/métodos , Neuropeptídeo Y/metabolismo , Células PC12 , Peroxissomos/fisiologia , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Vesículas Secretórias/ultraestrutura , Proteína rab3A de Ligação ao GTP/metabolismo
19.
IEEE Trans Inf Technol Biomed ; 10(4): 696-704, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17044403

RESUMO

The purpose of this paper is to integrate the technologies of radio frequency identification, global positioning system, global system for mobile communications, and geographic information system (GIS) to construct a stray prevention system for elderly persons suffering from dementia without interfering with their activities of daily livings. We also aim to improve the passive and manpowered way of searching the missing patient with the help of the information technology. Our system provides four monitoring schemes, including indoor residence monitoring, outdoor activity area monitoring, emergency rescue, and remote monitoring modes, and we have developed a service platform to implement these monitoring schemes. The platform consists of a web service server, a database server, a message controller server, and a health-GIS (H-GIS) server. Family members or volunteer workers can identify the real-time positions of missing elderly using mobile phone, PDA, Notebook PC, and various mobile devices through the service platform. System performance and reliability is analyzed. Experiments performed on four different time slots, from three locations, through three mobile telecommunication companies show that the overall transaction time is 34 s and the average deviation of the geographical location is about 8 m. A questionnaire surveyed by 11 users show that eight users are satisfied with the system stability and 10 users would like to carry the locating device themselves, or recommend it to their family members.


Assuntos
Demência/enfermagem , Sistemas de Informação Geográfica/instrumentação , Monitorização Ambulatorial/instrumentação , Cuidados de Enfermagem/métodos , Processamento de Sinais Assistido por Computador/instrumentação , Telemedicina/instrumentação , Telemetria/instrumentação , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Masculino , Monitorização Ambulatorial/métodos , Telemedicina/métodos , Telemetria/métodos , Interface Usuário-Computador
20.
Am J Chin Med ; 34(1): 23-36, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16437736

RESUMO

In this research, heart rate variability (HRV), pulse rate variability (PRV) and human skin conductance (SC) of all acupoints on Heart Meridian were used to evaluate the effects of electrical acupuncture (EA) on acupoint BL15 (Bladder Meridian). Ten healthy volunteers (aged 23 +/- 6) were selected as the control group on the first day, and then used again as the experimental group on the second day. The control group received sham EA during the study, while subjects of the experimental group were stimulated by 2 Hz EA on acupoint BL15 for 10 minutes. Electrocardiogram (ECG), wrist blood pressure pulse meter and skin conductance response (SCR) device were used to measure and analyze HRV, PRV and SCR for the two groups before and after stimulation. From the spectrum analysis of ECG and pulse pressure graph, we found that the EA applied on BL15 could induce a significant increase in the normalized high frequency power (nHFP) component of HRV and PRV, as well as a significant decrease in the normalized low frequency power (nLFP) part (p < 0.05). Moreover, both the heart rate and pulse rate were reduced in the analysis of the time domain of ECG and PRV. Furthermore, most of the SCR values at acupoints were decreased after stimulation. These results also indicate that the stimulation of BL15 by EA could cause relaxation, calmness and reduce feeling of tension or distress.


Assuntos
Resposta Galvânica da Pele , Frequência Cardíaca , Meridianos , Pulso Arterial , Adulto , Eletroacupuntura , Eletrocardiografia , Humanos , Processamento de Sinais Assistido por Computador
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...