35 results on '"Chai, Pei"'
Search Results
2. Fast and accurate generation method of PSF-based system matrix for PET reconstruction
- Author
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Sun, Xiao-Li, Liu, Shuang-Quan, Yun, Ming-Kai, Li, Dao-Wu, Gao, Juan, Li, Mo-Han, Chai, Pei, Tang, Hao-Hui, Zhang, Zhi-Ming, and Wei, Long
- Subjects
Physics - Medical Physics - Abstract
Positional single photon incidence response (P-SPIR) theory is researched in this paper to generate more accurate PSF-contained system matrix simply and quickly. The method has been proved highly effective to improve the spatial resolution by applying to the Eplus-260 primate PET designed by the Institute of High Energy Physics of the Chinese Academy of Sciences(IHEP). Simultaneously, to meet the clinical needs, GPU acceleration is put to use. Basically, P-SPIR theory takes both incidence angle and incidence position by crystal subdivision instead of only incidence angle into consideration based on Geant4 Application for Emission Tomography (GATE). The simulation conforms to the actual response distribution and can be completed rapidly within less than 1s. Furthermore,two-block penetration and normalization of the response probability are raised to fit the reality. With PSF obtained, the homogenization model is analyzed to calculate the spread distribution of bins within a few minutes for system matrix generation. As a reult, The images reconstructed indicate that the P-SPIR method can effectively inhibit the depth of interaction (DOI) effect especially in the field close to the edge of the field of view (FOV). What is more, the method can be promoted to any other PET and the list-mode organization structure high-speedily and efficiently, which substantially reduces the computing cost and ensures the accuracy of system matrix for PET reconstruction., Comment: 6 pages,12 figures
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- 2016
- Full Text
- View/download PDF
3. Comparative analysis of tangential flow filtration and ultracentrifugation, both combined with subsequent size exclusion chromatography, for the isolation of small extracellular vesicles
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Kekoolani S. Visan, Richard J. Lobb, Sunyoung Ham, Luize G. Lima, Carlos Palma, Chai Pei Zhi Edna, Li‐Ying Wu, Harsha Gowda, Keshava K. Datta, Gunter Hartel, Carlos Salomon, and Andreas Möller
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cell culture ,extracellular vesicles ,isolation ,tangential flow filtration ,Cytology ,QH573-671 - Abstract
Abstract Small extracellular vesicles (sEVs) provide major promise for advances in cancer diagnostics, prognostics, and therapeutics, ascribed to their distinctive cargo reflective of pathophysiological status, active involvement in intercellular communication, as well as their ubiquity and stability in bodily fluids. As a result, the field of sEV research has expanded exponentially. Nevertheless, there is a lack of standardisation in methods for sEV isolation from cells grown in serum‐containing media. The majority of researchers use serum‐containing media for sEV harvest and employ ultracentrifugation as the primary isolation method. Ultracentrifugation is inefficient as it is devoid of the capacity to isolate high sEV yields without contamination of non‐sEV materials or disruption of sEV integrity. We comprehensively evaluated a protocol using tangential flow filtration and size exclusion chromatography to isolate sEVs from a variety of human and murine cancer cell lines, including HeLa, MDA‐MB‐231, EO771 and B16F10. We directly compared the performance of traditional ultracentrifugation and tangential flow filtration methods, that had undergone further purification by size exclusion chromatography, in their capacity to separate sEVs, and rigorously characterised sEV properties using multiple quantification devices, protein analyses and both image and nano‐flow cytometry. Ultracentrifugation and tangential flow filtration both enrich consistent sEV populations, with similar size distributions of particles ranging up to 200 nm. However, tangential flow filtration exceeds ultracentrifugation in isolating significantly higher yields of sEVs, making it more suitable for large‐scale research applications. Our results demonstrate that tangential flow filtration is a reliable and robust sEV isolation approach that surpasses ultracentrifugation in yield, reproducibility, time, costs and scalability. These advantages allow for implementation in comprehensive research applications and downstream investigations.
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- 2022
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4. A region segmentation based algorithm for building crystal position lookup table in scintillation detector
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Wang, Hai Peng, Yun, Ming Kai, Liu, Shuang Quan, Fan, Xin, Cao, Xue Xiang, Chai, Pei, and Shan, Bao Ci
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Physics - Instrumentation and Detectors ,I.1.2 - Abstract
In scintillation detector, scintillation crystals are typically made into 2-dimension modular array. The location of incident gamma-ray need be calibrated due to spatial response nonlinearity. Generally, position histograms, the characteristic flood response of scintillation detectors, are used for position calibration. In this paper, a position calibration method based on crystal position lookup table which maps the inaccurate location calculated by Anger logic to the exact hitting crystal position has been proposed, Firstly, position histogram is segmented into disconnected regions. Then crystal marking points are labeled by finding the centroids of regions. Finally, crystal boundaries are determined and crystal position lookup table is generated. The scheme is evaluated by the whole-body PET scanner and breast dedicated SPECT detector developed by Institute of High Energy Physics, Chinese Academy of Sciences. The results demonstrate that the algorithm is accurate, efficient, robust and general purpose., Comment: 9 pages, 10 figures
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- 2014
- Full Text
- View/download PDF
5. Research on law and countermeasures of gas over-limit accident in Yuwu Coal Mine based on mathematical statistics
- Author
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CHAI Pei, YANG Ming, MAO Junrui, LIU Lei
- Subjects
gas over-limit ,control chart method ,coupling analysis ,countermeasure research ,accident-cause ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Gas over-limit is the cause of gas explosion accident. In order to analyze the regularity of gas over-limit accidents, based on the gas over-limit accidents from January 2018 to August 2019 in Yuwu Coal Mine, by using mathematical statistics, we study the frequency, location and duration of early warning of accidents, and the results show that the highest accident rate is in the 01:00-02:00 and 06:00-07:00 time periods, and the overall accident rate is still within the controllable range, and 88% of the accidents occurred in the driving surface; most of the accidents have the characteristics of short duration and low concentration; the accidents are mainly concentrated in the air cylinder replacement operation, coal cutting operation, and drilling operation.
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- 2021
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6. Neuropathology changed by 3- and 6-months low-level PM2.5 inhalation exposure in spontaneously hypertensive rats
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Chuang, Hsiao-Chi, Chen, Hsin-Chang, Chai, Pei-Jui, Liao, Ho-Tang, Wu, Chang-Fu, Chen, Chia-Ling, Jhan, Ming-Kai, Hsieh, Hui-I, Wu, Kuen-Yuh, Chen, Ta-Fu, and Cheng, Tsun-Jen
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- 2020
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7. Significance of Physical Status and Liver Function Reserve for Outcome of Patients with Advanced Hepatocellular Carcinoma Receiving Lenvatinib Treatment
- Author
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Chan, Kun-Ming, primary, Lai, Yin, additional, Hung, Hao-Chien, additional, Lee, Jin-Chiao, additional, Cheng, Chih-Hsien, additional, Wang, Yu-Chao, additional, Wu, Tsung-Han, additional, Lee, Chen-Fang, additional, Wu, Ting-Jung, additional, Chou, Hong-Shiue, additional, Wang, Ching-Ting, additional, Chai, Pei-Mei, additional, Lien, Hsin-Yi, additional, and Lee, Wei-Chen, additional
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- 2023
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8. Similar efficacy and safety between lenvatinib versus atezolizumab plus bevacizumab as the first‐line treatment for unresectable hepatocellular carcinoma
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Su, Chung‐Wei, primary, Teng, Wei, additional, Lin, Po‐Ting, additional, Jeng, Wen‐Juei, additional, Chen, Kuei‐An, additional, Hsieh, Yi‐Chung, additional, Chen, Wei‐Ting, additional, Ho, Ming‐Mo, additional, Hsieh, Chia‐Hsun, additional, Wang, Ching‐Ting, additional, Chai, Pei‐Mei, additional, Lin, Chen‐Chun, additional, Lin, Chun‐Yen, additional, and Lin, Shi‐Ming, additional
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- 2022
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9. Differential Response to Sorafenib Administration for Advanced Hepatocellular Carcinoma
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Huang, Song-Fong, primary, Chong, Sio-Wai, additional, Huang, Chun-Wei, additional, Hsu, Heng-Yuan, additional, Pan, Kuang-Tse, additional, Hung, Chien-Fu, additional, Wu, Tsung-Han, additional, Lee, Chao-Wei, additional, Hsieh, Chia-Hsun, additional, Wang, Ching-Ting, additional, Chai, Pei-Mei, additional, and Yu, Ming-Chin, additional
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- 2022
- Full Text
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10. Comparative analysis of tangential flow filtration and ultracentrifugation, both combined with subsequent size exclusion chromatography, for the isolation of small extracellular vesicles
- Author
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Visan, Kekoolani S., primary, Lobb, Richard J., additional, Ham, Sunyoung, additional, Lima, Luize G., additional, Palma, Carlos, additional, Edna, Chai Pei Zhi, additional, Wu, Li‐Ying, additional, Gowda, Harsha, additional, Datta, Keshava K., additional, Hartel, Gunter, additional, Salomon, Carlos, additional, and Möller, Andreas, additional
- Published
- 2022
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11. Similar efficacy and safety between lenvatinib versus atezolizumab plus bevacizumab as the first‐line treatment for unresectable hepatocellular carcinoma.
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Su, Chung‐Wei, Teng, Wei, Lin, Po‐Ting, Jeng, Wen‐Juei, Chen, Kuei‐An, Hsieh, Yi‐Chung, Chen, Wei‐Ting, Ho, Ming‐Mo, Hsieh, Chia‐Hsun, Wang, Ching‐Ting, Chai, Pei‐Mei, Lin, Chen‐Chun, Lin, Chun‐Yen, and Lin, Shi‐Ming
- Subjects
HEPATOCELLULAR carcinoma ,BEVACIZUMAB ,ATEZOLIZUMAB ,PROGRESSION-free survival ,VIRAL hepatitis - Abstract
Background: Lenvatinib and atezolizumab plus bevacizumab(A + B) have been used for unresectable hepatocellular carcinoma (HCC) as first‐line therapy. Real‐world studies comparison of efficacy and safety in these two regimens are limited, we therefore conduct this study to investigate these issues. Methods: We retrospectively reviewed patients received lenvatinib (n = 46) and A + B (n = 46) as first‐line systemic therapy for unresectable HCC in a tertiary medical center. Objective response rate (ORR), progression free survival (PFS), and overall survival (OS) were evaluated according to modified Response Evaluation Criteria in Solid Tumors (mRECIST). Inverse probability weighting (IPW) was performed for baseline clinical features balance. Results: A total of 92 patients with median age of 63.8 year‐old, 78.3% male, 85.9% viral hepatitis infected, 67.4% BCLC stage C were enrolled. The median treatment and follow‐up duration were 4.7 months and 9.4 months, respectively. There was no significant difference in ORR (26.1% vs. 41.3%, p = 0.1226), PFS (5.9 vs. 5.3 months, p = 0.4066), and OS (not reached vs. not reached, p = 0.7128) between the lenvatinib and A + B groups. After IPW, the results of survival and response rate were also compared. Subgroup analysis suggested that using lenvatinib was not inferior to A + B in regards of PFS, including those with elder, Child‐Pugh class B, beyond up‐to‐seven, or portal vein invasion VP4 patients. Among the lenvatinib treated patients, multivariate analysis showed patients elder than 65‐year‐old was an independent predictor associated with shorter PFS (adjust HR: 2.085[0.914–4.753], p = 0.0213). The incidence rates of adverse events were similar between two groups (76 vs. 63%, p = 0.1740). Both of two regimens had similarly few impact on liver function by comparison of baseline, third month, and sixth month albumin‐bilirubin index and Child‐Pugh score. Conclusions: The efficacy and safety of lenvatinib are similar to A + B as a first‐line systemic therapy for unresectable HCC. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Dynamic Change of Albumin-Bilirubin Score Is Good Predictive Parameter for Prognosis in Chronic Hepatitis C-hepatocellular Carcinoma Patients Receiving Transarterial Chemoembolization
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Lin, Po-Ting, primary, Teng, Wei, additional, Jeng, Wen-Juei, additional, Chen, Wei-Ting, additional, Hsieh, Yi-Chung, additional, Huang, Chien-Hao, additional, Lui, Kar-Wai, additional, Hung, Chen-Fu, additional, Wang, Ching-Ting, additional, Chai, Pei-Mei, additional, Lin, Chen-Chun, additional, Lin, Chun-Yen, additional, Lin, Shi-Ming, additional, and Sheen, I-Shyan, additional
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- 2022
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13. Use of probiotics in clinical practice with special reference to diarrheal diseases: A position statement of the Malaysian Society of Gastroenterology and Hepatology
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Lee, Yeong‐Yeh, primary, Leow, Alex H‐R, additional, Chai, Pei‐Fan, additional, Raja Ali, Raja Affendi, additional, Lee, Way‐Seah, additional, and Goh, Khean‐Lee, additional
- Published
- 2020
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14. Rotavirus genotypes in Malaysia and Universal rotavirus vaccination
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Lee, Way Seah, Ying Lim, Benjamin Tze, Chai, Pei Fan, Kirkwood, Carl D., and Foo Lee, Jimmy Kok
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- 2012
15. Field Deployment Experience of Low-Cost Smart City Air Pollution Monitoring Network
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Lau, Seng-Yong, Chen, Yu-Ting, Chen, Chai-Pei, Wang, Yeuh-Bin, Chang, Shuenn-Chin, Lin, Lung-Chi, and Pao, Chih-Ming
- Subjects
DATA processing & computer science ,ddc:004 - Published
- 2019
16. Development of a PET Insert for simultaneously small animal PET/MRI
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Wang, Yingjie, Zhang, Zhiming, Li, Daowu, Liu, Shuangquan, Wang, Peilin, Feng, Baotong, Chai, Pei, and Wei, Long
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- 2015
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17. A population stereotaxic positron emission tomography brain template for the macaque and its application to ischemic model
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Steven H. Liang, Chai Pei, Hsiao-Ying Wey, Yongjin Tang, Gong Jianxian, Chao Zheng, Shengxiang Liang, Zhangsheng Pan, Xudong Zhao, Zhiqiang Tan, Baoci Shan, Yichao Hu, Lu Wang, Xiaofei Zhang, Jingjie Shang, Hao Xu, and Binbin Nie
- Subjects
Male ,Computer science ,Cognitive Neuroscience ,Population ,Ischemia ,Macaque ,050105 experimental psychology ,Brain Ischemia ,03 medical and health sciences ,Atlases as Topic ,0302 clinical medicine ,Imaging Tool ,Species Specificity ,Neuroimaging ,biology.animal ,Image Processing, Computer-Assisted ,medicine ,T1 weighted ,Animals ,0501 psychology and cognitive sciences ,education ,Brain Mapping ,education.field_of_study ,medicine.diagnostic_test ,biology ,business.industry ,05 social sciences ,Brain atlas ,Brain ,Pattern recognition ,medicine.disease ,Macaca mulatta ,Magnetic Resonance Imaging ,Macaca fascicularis ,Neurology ,Positron emission tomography ,Positron-Emission Tomography ,Female ,Artificial intelligence ,business ,030217 neurology & neurosurgery - Abstract
Purpose Positron emission tomography (PET) is a non-invasive imaging tool for the evaluation of brain function and neuronal activity in normal and diseased conditions with high sensitivity. The macaque monkey serves as a valuable model system in the field of translational medicine, for its phylogenetic proximity to man. To translation of non-human primate neuro-PET studies, an effective and objective data analysis platform for neuro-PET studies is needed. Materials and methods A set of stereotaxic templates of macaque brain, namely the Institute of High Energy Physics & Jinan University Macaque Template (HJT), was constructed by iteratively registration and averaging, based on 30 healthy rhesus monkeys. A brain atlas image was created in HJT space by combining sub-anatomical regions and defining new 88 bilateral functional regions, in which a unique integer was assigned for each sub-anatomical region. Results The HJT comprised a structural MRI T1 weighted image (T1WI) template image, a functional FDG-PET template image, intracranial tissue segmentations accompanied with a digital macaque brain atlas image. It is compatible with various commercially available software tools, such as SPM and PMOD. Data analysis was performed on a stroke model compared with a group of healthy controls to demonstrate the usage of HJT. Conclusion We have constructed a stereotaxic template set of macaque brain named HJT, which standardizes macaque neuroimaging data analysis, supports novel radiotracer development and facilitates translational neuro-disorders research.
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- 2019
18. Use of probiotics in clinical practice with special reference to diarrheal diseases: A position statement of the Malaysian Society of Gastroenterology and Hepatology.
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Lee, Yeong‐Yeh, Leow, Alex H‐R, Chai, Pei‐Fan, Raja Ali, Raja Affendi, Lee, Way‐Seah, and Goh, Khean‐Lee
- Subjects
GASTROENTEROLOGY ,HEPATOLOGY - Abstract
Probiotics comprise a large group of microorganisms, which have different properties and thus confer different benefits. The use of probiotics has shown promising results in the management of diarrheal diseases. While the availability of probiotic products has flourished in the marketplace, there is limited guidance on the selection of probiotics for clinical use. This position paper is aimed at informing clinicians about the proper selection criteria of probiotics based on current evidence on strain‐specific efficacy and safety for the management of diarrheal diseases. Members of the working group discussed issues on probiotic use in clinical practice, which were then drafted into statements. Literature to support or refute the statements were gathered through a search of medical literature from 2011 to 2020. Recommendations were formulated based on the drafted statements and evidence gathered, revised as necessary, and finalized upon agreement of all members. Twelve statements and recommendations were developed covering the areas of quality control in the manufacturing of probiotics, criteria for selection of probiotics, and established evidence for use of probiotics in diarrheal diseases in adults and children. Recommendations for the use of specific probiotic strains in clinical practice were categorized as proven and probable efficacy based on strength of evidence. Robust evidence is available to support the use of probiotics for diarrheal diseases in clinical practice. Based on the results obtained, we strongly advocate the careful evaluation of products, including manufacturing practices, strain‐specific evidence, and contraindications for at‐risk populations when choosing probiotics for use in clinical practice. [ABSTRACT FROM AUTHOR]
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- 2021
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19. Genomic Disruption of FOXL2 in Blepharophimosis-Ptosis-Epicanthus Inversus Syndrome Type 2
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Niu, Bei-Bei, primary, Tang, Ning, additional, Xu, Qin, additional, and Chai, Pei-Wei, additional
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- 2018
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20. Fast and accurate generation method of PSF-based system matrix for PET reconstruction
- Author
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Haohui Tang, Gao Juan, Long Wei, Zhiming Zhang, Liu Shuangquan, Chai Pei, Daowu Li, Xiao-Li Sun, Li Mohan, and Yun Mingkai
- Subjects
Physics ,Point spread function ,Nuclear and High Energy Physics ,Photon ,medicine.diagnostic_test ,010308 nuclear & particles physics ,Monte Carlo method ,FOS: Physical sciences ,Astronomy and Astrophysics ,Image processing ,Iterative reconstruction ,01 natural sciences ,Homogenization (chemistry) ,Physics - Medical Physics ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,0103 physical sciences ,medicine ,Tomography ,Medical Physics (physics.med-ph) ,Instrumentation ,Algorithm ,Emission computed tomography - Abstract
Positional single photon incidence response (P-SPIR) theory is researched in this paper to generate more accurate PSF-contained system matrix simply and quickly. The method has been proved highly effective to improve the spatial resolution by applying to the Eplus-260 primate PET designed by the Institute of High Energy Physics of the Chinese Academy of Sciences(IHEP). Simultaneously, to meet the clinical needs, GPU acceleration is put to use. Basically, P-SPIR theory takes both incidence angle and incidence position by crystal subdivision instead of only incidence angle into consideration based on Geant4 Application for Emission Tomography (GATE). The simulation conforms to the actual response distribution and can be completed rapidly within less than 1s. Furthermore,two-block penetration and normalization of the response probability are raised to fit the reality. With PSF obtained, the homogenization model is analyzed to calculate the spread distribution of bins within a few minutes for system matrix generation. As a reult, The images reconstructed indicate that the P-SPIR method can effectively inhibit the depth of interaction (DOI) effect especially in the field close to the edge of the field of view (FOV). What is more, the method can be promoted to any other PET and the list-mode organization structure high-speedily and efficiently, which substantially reduces the computing cost and ensures the accuracy of system matrix for PET reconstruction., Comment: 6 pages,12 figures
- Published
- 2016
- Full Text
- View/download PDF
21. Development of a PET Insert for simultaneously small animal PET/MRI
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Zhiming Zhang, Long Wei, Wang Yingjie, P. L. Wang, Baotong Feng, Liu Shuangquan, Chai Pei, and Daowu Li
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Radiation ,Materials science ,Coaxial cable ,business.industry ,Detector ,Biomedical Engineering ,Signal ,Imaging phantom ,Lyso ,law.invention ,Silicon photomultiplier ,Optics ,law ,Meeting Abstract ,Electromagnetic shielding ,Radiology, Nuclear Medicine and imaging ,Tomography ,business ,Nuclear medicine ,Instrumentation - Abstract
PET/MR is a new multi-modality imaging system which provide both structural and functional information with good soft tissue imaging ability and no ionizing radiation. In recent years, PET/MR is under major progress because of the development of silicon photomultipliers (SiPM). The goal of this study is to develop a MRI compatible PET insert based on SiPM and LYSO scintillator. The PET system was constituted by the detector ring, electronics and software. The detector ring consists of 16 detector module. The inner diameter of the ring was 151 mm, the external diameter was 216 mm, which was big enough for small animal research, e.g. rat, rabbit and tupaia. The sensor of each module was 2*2 SensL SPMArraySL, coupled with an array of 14 x 14 LYSO crystals, each crystal measuring 2 mm x 2 mm 10 mm. The detector was encapsulated in a copper box for light and magnetic shielding. Resister charge multiplexing circuit was used in the front end electronics. Each detector output 8X and 8Y position signals. One summed timing signal was extracted from the common cathode of all 64 channels. All these signals were transmitted to digital electronic board by a 3 m long coaxial cable from inside of the MR to the outside. Each digital electronic board handled 8 detector modules based on FPGA to obtain the timing, position and energy information of a single event. And then these single events were sent to the coincidence processing board to produce coincidence packets which are prepared for further processing. A 0.2mCi 68Ge line source was used to do the preliminary imaging test. The image was reconstructed by 3D-OSEM algorithm. The initial result proved the system to be feasible as a PET. FDG phantom imaging and simultaneous PET/MR imaging are in progress.
- Published
- 2015
22. A region segmentation based algorithm for building crystal position lookup table in scintillation detector
- Author
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Hai Peng Wang, Shuang Quan Liu, Ming Kai Yun, Xue Xiang Cao, Chai Pei, Bao Ci Shan, and Xin Fan
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Nuclear and High Energy Physics ,Scintillation ,Physics - Instrumentation and Detectors ,Computer science ,Physics::Instrumentation and Detectors ,Detector ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,FOS: Physical sciences ,Centroid ,Astronomy and Astrophysics ,Instrumentation and Detectors (physics.ins-det) ,Scintillator ,I.1.2 ,Position (vector) ,Histogram ,Lookup table ,Calibration ,Instrumentation ,Algorithm - Abstract
In scintillation detector, scintillation crystals are typically made into 2-dimension modular array. The location of incident gamma-ray need be calibrated due to spatial response nonlinearity. Generally, position histograms, the characteristic flood response of scintillation detectors, are used for position calibration. In this paper, a position calibration method based on crystal position lookup table which maps the inaccurate location calculated by Anger logic to the exact hitting crystal position has been proposed, Firstly, position histogram is segmented into disconnected regions. Then crystal marking points are labeled by finding the centroids of regions. Finally, crystal boundaries are determined and crystal position lookup table is generated. The scheme is evaluated by the whole-body PET scanner and breast dedicated SPECT detector developed by Institute of High Energy Physics, Chinese Academy of Sciences. The results demonstrate that the algorithm is accurate, efficient, robust and general purpose., 9 pages, 10 figures
- Published
- 2014
23. Automatic method for tracing regions of interest in rat brain magnetic resonance imaging studies
- Author
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Shujun Zhao, Liu Shuangquan, Jiaojie Hui, Chai Pei, Binbin Nie, Baoci Shan, Juan Gao, Lijing Wang, and Zhijun Zhang
- Subjects
Male ,Models, Anatomic ,Jaccard index ,Computer science ,Image processing ,Tracing ,Hippocampus ,Pattern Recognition, Automated ,Rats, Sprague-Dawley ,Atlas (anatomy) ,Approximation error ,medicine ,Image Processing, Computer-Assisted ,Animals ,Radiology, Nuclear Medicine and imaging ,Brain Mapping ,Electronic Data Processing ,medicine.diagnostic_test ,business.industry ,Brain ,Reproducibility of Results ,Magnetic resonance imaging ,Pattern recognition ,Rat brain ,Magnetic Resonance Imaging ,Rats ,Sprague dawley ,medicine.anatomical_structure ,Female ,Artificial intelligence ,business - Abstract
Purpose To automatically extract regions of interest (ROIs) and simultaneously preserve the anatomical characteristics of each individual, we developed a new atlas-based method utilizing a pair of coregistered brain template and digital atlas. Materials and Methods Unlike the previous atlas-based method, this method treats each individual as the target image, and the template and atlas are each transformed to register with the individual. To evaluate the accuracy of this method we implemented it in extracting the hippocampus from two groups of T2-weighted structural images with different spatial resolutions and a group of T2*-weighted functional images. Furthermore, the results were compared against a manually segmented hippocampus and an atlas-derived hippocampus. Results Jaccard similarity (JS) reached 84.7%–90.5%, and relative error in volume (RV) was 4.8%–12.7%. The consistency observed between the results of the proposed method and manual drawing was therefore considerable. Conclusion We developed a new atlas-based method for ROI extraction that can automatically extract ROI and simultaneously preserve each individual's unique anatomical characteristics. J. Magn. Reson. Imaging 2010;32:830–835. © 2010 Wiley-Liss, Inc.
- Published
- 2010
24. Attenuation correction with region growing method used in the positron emission mammography imaging system
- Author
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Yun Mingkai, Peng-Fei Yin, Chai Pei, Long Wei, Gu Xiaoyue, Fan Xin, Lin Li, Xiao-Li Sun, and Huang Xianchao
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Nuclear and High Energy Physics ,Image quality ,Computer science ,business.industry ,Breast imaging ,Threshold limit value ,FOS: Physical sciences ,Astronomy and Astrophysics ,Pattern recognition ,Image segmentation ,Physics - Medical Physics ,Region growing ,Positron emission mammography ,Segmentation ,Medical Physics (physics.med-ph) ,Artificial intelligence ,business ,Instrumentation ,Correction for attenuation - Abstract
Positron Emission Mammography imaging system (PEMi) is a nuclear medicine diagnosis method dedicated for breast imaging. It provides a better resolution in detection of millimeter-sized breast tumors than whole-body PET. To address the requirement of semi-quantitative analysis with the radiotracer concentration map of the breast, a new attenuation correction method based on three-dimensional seeded region growing image segmentation (3DSRG-AC) solution was developed. The method gives a 3D connected region as the segmentation result instead of image slices. The continuously segmentation property makes this new method free of activity variation of breast tissues. Threshold value chosen is the key point for the segmentation process. The first valley of the grey level histogram of the reconstruction image is set as the lower threshold, which works fine in clinical application. Results show that attenuation correction for PEMi improves the image quality and the quantitative accuracy of radioactivity distribution determination. Attenuation correction also improves the probabilities to detect small and early breast tumors.
- Published
- 2015
25. PET image reconstruction with a system matrix containing point spread function derived from single photon incidence response
- Author
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Wang Hai-Peng, Yun Ming-Kai, Sun Xiao-Li, Cao Xue-Xiang, Liu Bao-dong, Li Daowu, Wang Lu, Fan Xin, Liu Shuang-Quan, Chai Pei, and Wei Long
- Subjects
Point spread function ,Physics ,Photon ,business.industry ,Monte Carlo method ,Physics::Optics ,General Physics and Astronomy ,Image processing ,Iterative reconstruction ,Coincidence ,Matrix (mathematics) ,Optics ,Ordered subset expectation maximization ,business - Abstract
A point spread function (PSF) for the blurring component in positron emission tomography (PET) is studied. The PSF matrix is derived from the single photon incidence response function. A statistical iterative reconstruction (IR) method based on the system matrix containing the PSF is developed. More specifically, the gamma photon incidence upon a crystal array is simulated by Monte Carlo (MC) simulation, and then the single photon incidence response functions are calculated. Subsequently, the single photon incidence response functions are used to compute the coincidence blurring factor according to the physical process of PET coincidence detection. Through weighting the ordinary system matrix response by the coincidence blurring factors, the IR system matrix containing the PSF is finally established. By using this system matrix, the image is reconstructed by an ordered subset expectation maximization (OSEM) algorithm. The experimental results show that the proposed system matrix can substantially improve the image radial resolution, contrast, and noise property. Furthermore, the simulated single gamma-ray incidence response function depends only on the crystal configuration, so the method could be extended to any PET scanner with the same detector crystal configuration.
- Published
- 2015
26. Carica papaya increases regulatory T cells and reduces IFN-ã+ CD4+ T cells in healthy human subjects.
- Author
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Abdullah, Maha, Kandiah, Mirnalini, Vidyadaran, Sharmili, Seow, Heng Fong, Seman, Zainina, Chai, Pei Shin, Loh, Chiew Yee, Chong, Mun Yee, Quay, Huai Wei, Abdullah, Maha, Kandiah, Mirnalini, Vidyadaran, Sharmili, Seow, Heng Fong, Seman, Zainina, Chai, Pei Shin, Loh, Chiew Yee, Chong, Mun Yee, and Quay, Huai Wei
- Abstract
Fruit and vegetables have therapeutic potential as they dampen inflammation, have no known side-effects and as whole foods have prospective additive and synergistic benefits. Th1 (IFN-γ(+) CD4(+))/Th2 (IL-4(+)CD4(+)) T cells play a vital role in mediating inflammatory responses and may be regulated by regulatory T cells (Tregs). Effects of Carica papaya on cells of healthy individuals were determined using flow cytometry methods. Significant down-regulation of IFN-γ(+) CD4(+) (p=0.03, n=13), up-regulation of IL-4(+) CD4(+) (p=0.04, n=13) T cells and up-regulation of CD3(+) CD4(+) CD25(+) CD127(-) (p=0.001, n=15) Tregs were observed after papaya consumption. In vitro cultures showed up-regulation of Tregs in male subjects and was significantly associated with levels of IL-1β in culture supernatants (R(2) =0.608, p=0.04, n=12). Other inflammatory cytokines were significantly suppressed. Papaya consumption may exert an anti-inflammatory response mediated through Tregs and have potential in alleviating inflammatory conditions.
- Published
- 2011
27. In Vitro Immunomodulatory Effects of Selected Fruits and Herbs on Human Peripheral Blood Mononuclear Cells
- Author
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Chai, Pei Shin and Chai, Pei Shin
- Abstract
Although the immune system serves as the defensive mechanism of our body, a weakened or overactive immune system predisposes the body to infection and various other diseases such as cancers, allergies and immune diseases. Due to costs and the growing concerns regarding the side effects of conventional drugs, many patients are seeking alternative treatments. Natural food like fruits, herbs and spices has long been used in folklore remedies to cure many diseases and boost the immune system. In this study, the immunomodulatory effects of papaya (Carica papaya) fruits, mata kucing (Euphoria malaiensis) fruits, dang shen (Codonopsis pilosula) and Pu-erh tea (Camellia sinensis var. assamica)weredetermined using flow cytometry. A culture system using human peripheral blood mononuclear cells (PBMC) was used. High cell viability and increased proliferation of PBMC together with immunophenotyping results showed that the culture system provides a good system to study the subpopulations of PBMC. MTS and tritiated thymidine incorporation assay showed that these extracts have some proliferative effect on PBMC and limited cytotoxicity at the concentrations tested. Immunophenotyping results showed that papaya and mata kucing were able to upregulate the percentage of immune cells such as NK, NKT and monocytes (for papaya). They may also modulate regulatory functions, for example, by increasing Tregs and suppressing inhibitory cytokines such as IL10 (for papaya). Our results demonstrated that these fruits may have potential as immune-booster and regulator, anti allergy, anti cancer and anti inflammatory (papaya) agents. Dang shen and tea showed suppressive effect on proinflammatory cytokine production in cultured PBMC.We also observed stimulatory effect on the percentages of T cells (CD3+), B cells (CD3-19+), NK (CD3-56+), and NKT (CD3+56+) cells which could support their roles as traditional immune boosters. However, these food extracts were also observed to increase activation of i
- Published
- 2010
28. Optical Cache Memory
- Author
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PHYSICAL OPTICS CORP TORRANCE CA, Kuo, Chai-Pei, PHYSICAL OPTICS CORP TORRANCE CA, and Kuo, Chai-Pei
- Abstract
The goal of this effort is to build an Exploratory Development Model (EDM), of an optical cache memory utilizing existing off-the-shelf components to demonstrate system feasibility, key system concepts, and validation of the overall system approach. An optical parallel addressing architecture was identified which utilizes a vector-matrix inner product as the basic frame work for an optical cache memory system. Furthermore, in order to mimic the dynamic memory requisition and updating sequence that is encountered in an electronic system, a polymeric memory material was studied and its performance was tailored to provide long memory persistence, fast writing, fast erasing, and high efficiency.
- Published
- 1991
29. Rotavirus genotypes in Malaysia and Universal rotavirus vaccination.
- Author
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Way Seah Lee, Ying Lim, Benjamin Tze, Chai, Pei Fan, Kirkwood, Carl D., and Lee, Jimmy Kok Foo
- Published
- 2012
- Full Text
- View/download PDF
30. Neuropathology changed by 3- and 6-months low-level PM2.5 inhalation exposure in spontaneously hypertensive rats.
- Author
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Chuang, Hsiao-Chi, Chen, Hsin-Chang, Chai, Pei-Jui, Liao, Ho-Tang, Wu, Chang-Fu, Chen, Chia-Ling, Jhan, Ming-Kai, Hsieh, Hui-I, Wu, Kuen-Yuh, Chen, Ta-Fu, and Cheng, Tsun-Jen
- Subjects
NEUROLOGICAL disorders ,OLFACTORY bulb ,PARTICULATE matter ,HIPPOCAMPUS (Brain) ,HYPERTENSION - Abstract
Background: Epidemiological evidence has linked fine particulate matter (PM
2.5 ) to neurodegenerative diseases; however, the toxicological evidence remains unclear. The objective of this study was to investigate the effects of PM2.5 on neuropathophysiology in a hypertensive animal model. We examined behavioral alterations (Morris water maze), lipid peroxidation (malondialdehyde (MDA)), tau and autophagy expressions, neuron death, and caspase-3 levels after 3 and 6 months of whole-body exposure to urban PM2.5 in spontaneously hypertensive (SH) rats. Results: SH rats were exposed to S-, K-, Si-, and Fe-dominated PM2.5 at 8.6 ± 2.5 and 10.8 ± 3.8 μg/m3 for 3 and 6 months, respectively. We observed no significant alterations in the escape latency, distance moved, mean area crossing, mean time spent, or mean swimming velocity after PM2.5 exposure. Notably, levels of MDA had significantly increased in the olfactory bulb, hippocampus, and cortex after 6 months of PM2.5 exposure (p < 0.05). We observed that 3 months of exposure to PM2.5 caused significantly higher expressions of t-tau and p-tau in the olfactory bulb (p < 0.05) but not in other brain regions. Beclin 1 was overexpressed in the hippocampus with 3 months of PM2.5 exposure, but significantly decreased in the cortex with 6 months exposure to PM2.5 . Neuron numbers had decreased with caspase-3 activation in the cerebellum, hippocampus, and cortex after 6 months of PM2.5 exposure. Conclusions: Chronic exposure to low-level PM2.5 could accelerate the development of neurodegenerative pathologies in subjects with hypertension. [ABSTRACT FROM AUTHOR]- Published
- 2020
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31. Characterization of photoinduced gratings in optical glass fibers.
- Author
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Kuo, Chai-Pei. and Kuo, Chai-Pei.
- Abstract
The properties of photo-induced gratings in germania doped glass fibers were studied. Permanent phase gratings in a fiber core were fabricated by the mixing of two contra propagating waves. Experiments are described and results are presented which show that the strength of a photoinduced grating is strongly dependent on the writing power as well as the laser writing wavelength. A rigorous development of linear coupled mode theory for the contra propagation geometry is given and used to model the experimentally observed grating responses as a function of fine tuning frequency of probing light. Measurements have been done of the amplitude and phase response of the grating structure and compared with theoretical models of uniform and chirped gratings. The theoretically predicted negative group velocity dispersion in fiber grating was observed interferometrically and described in detail. The nonlinear coupled mode theory has been fully implemented in a computer program and some numerical results are given in the second part of this thesis. The dynamics of a pulse propagating in the fiber grating is simulated and the results show its dependence on pulse energy, frequency detuning, and the type of grating geometry. A limitation is found in the dispersion property of a constant amplitude fiber grating so that the pulse compression ratio and the width of a compressible pulse is strictly limited to ≅250 picoseconds.
- Published
- 1988
32. Comparing Lenvatinib/Pembrolizumab with Atezolizumab/Bevacizumab in Unresectable Hepatocellular Carcinoma: A Real-World Experience with Propensity Score Matching Analysis.
- Author
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Hsu YC, Lin PT, Teng W, Hsieh YC, Chen WT, Su CW, Wang CT, Chai PM, Lin CC, Lin CY, and Lin SM
- Abstract
Background: The combination of anti-angiogenic therapy and immune checkpoint inhibitors has revolutionized the management of unresectable hepatocellular carcinoma (uHCC). While an early-phase study demonstrated promising outcomes for lenvatinib plus pembrolizumab (L+P) in treating uHCC, the LEAP-002 trial did not meet its primary endpoint. However, the comparative efficacy between L+P and atezolizumab plus bevacizumab (A+B) as first-line treatment remains a topic of uncertainty. This study aimed to assess the effectiveness and safety of L+P in contrast to A+B among patients diagnosed with uHCC., Methods: We conducted a retrospective analysis of enrolled patients with uHCC who received L+P or A+B as initial systemic treatment at Chang Gung Memorial Hospital from June 2019 to December 2022. The overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR) by modified RECIST were compared., Results: 121 patients were recruited, with 37 receiving L+P and 84 receiving A+B. Among them, 95 (78.5%) patients were BCLC stage C, and 99 (81.8%) patients had viral etiology for HCC, predominantly chronic HBV (68.6%). Both the L+P and the A+B groups demonstrated comparable OS (18.2 months versus 14.6 months, p = 0.35) and PFS (7.3 months versus 8.9 months, p = 0.75). The ORR and DCR were similar. After propensity score matching, the results remained consistent between the matched patients. Treatment-related adverse events of any grade occurred in 30 (81.1%) in the L+P group and 62 (73.8%) in the A+B group., Conclusions: Our findings suggest that L+P and A+B exhibit comparable efficacy and safety profiles in real-world settings.
- Published
- 2024
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33. Locoregional treatment improves overall survival for liver cancer during second-line regorafenib or immune checkpoint inhibitor.
- Author
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Lin PT, Hsu YC, Kao YT, Teng W, Hsieh YC, Chen WT, Su CW, Wang CT, Chai PM, Lin CC, Lin CY, and Lin SM
- Abstract
For advanced hepatocellular carcinoma (HCC), the best second-line treatment after first-line treatment with sorafenib is unclear. This study aimed to compared the efficacy of second-line regorafenib (a tyrosine kinase inhibitor) and immune checkpoint inhibitors (ICIs) in patients with advanced HCC after sorafenib therapy. This retrospective study included 89 patients with HCC treated with sorafenib, and then regorafenib (n = 58) or an ICI (n = 31). Treatment response, overall survival (OS) and progression-free survival (PFS) of the 2 groups were compared, and factors associated with post-treatment mortality or disease progression were evaluated. During follow-up period, compared to regorafenib, treatment with an ICI results in a slight increase in a 20% decrease of AFP (35.7% vs. 31.8%), complete response rate (6.5% vs. 0%), objective response rate (16.1% vs. 6.9%), median overall survival (13.3 vs. 5 months), and median PFS (3.0 vs. 2.6 months). Combined locoregional treatment (LRT) (hazard ratio [HR] = 0.40, 95% confidence interval [CI]: 0.15-0.99) during second-line treatment was associated with a decreased risk of post-treatment mortality. After propensity scoring matching, combined LRT during second-line treatment had longer post-treatment OS than patients without combined LRT. A 20% decrease of AFP (HR = 0.54, 95% CI: 0.31-0.94) was associated with a decreased risk of post-treatment disease progression. In conclusions, second-line treatment with regorafenib or ICI prolongs OS in patients with advanced HCC treated with sorafenib. Combined LRT during second-line treatment is associated with decreased post-treatment mortality. A 20% decrease of AFP level may be predictive of a lower rate of disease progression., Competing Interests: None., (AJCR Copyright © 2024.)
- Published
- 2024
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- View/download PDF
34. Combination of CRAFITY score with Alpha-fetoprotein response predicts a favorable outcome of atezolizumab plus bevacizumab for unresectable hepatocellular carcinoma.
- Author
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Teng W, Lin CC, Su CW, Lin PT, Hsieh YC, Chen WT, Ho MM, Wang CT, Chai PM, Hsieh JC, Lin CY, and Lin SM
- Abstract
Immune checkpoint inhibitors (ICIs) with atezolizumab plus bevacizumab are promising agents for unresectable hepatocellular carcinoma (HCC). We tried to guide the treatment based on recent developed CRAFITY score combining with on-treatment AFP response. Eighty-nine patients who received atezolizumab plus bevacizumab regardless of as a first-line therapy or not for unresectable HCC were enrolled for analyses. Radiologic evaluation was based on modified Response Evaluation Criteria in Solid Tumors (mRECIST). The objective response rate (ORR) and disease control rate (DCR) were 25.0% and 65.5%, respectively. Multivariate analysis showed that low CRAFITY score (AFP<100 ng/ml or CRP<10 mg/l) and satisfactory AFP response at 6 weeks (≥75% decrease or ≤10% increase from baseline) were independent factors determining good overall survival (OS) (hazard ratio [HR]=0.143, P=0.002 & HR=0.337, P=0.031), progression-free survival (PFS) (HR=0.419, P=0.022 & HR=0.429, P=0.025) and good responder (odds ratio [OR]=1.763, P=0.044 & OR=3.881, P=0.011). Patients were further divided into three classes by combination of CRAFITY score and AFP response at 6 weeks [The CAR (CRAFITY score and AFP-Response) classification)]: low CRAFITY score with satisfactory AFP response at 6 weeks (class I), either high CRAFITY score or unsatisfactory AFP response at 6 weeks (class II) and high CRAFITY score together with unsatisfactory AFP response at 6 weeks (class III). ORR was 35.0%, 18.2%, and 0% in class I, II and III patients, respectively (overall P=0.034). Patients in the class I had the best OS and PFS, followed by class II and class III (median OS: not reached vs. 11.1 vs. 4.3 months, log-rank P<0.001; median PFS: 7.9 vs. 6.6 vs. 2.6 months, log-rank P=0.001). Combination CRAFITY score and AFP response at 6 weeks with AUROC predicts OS and tumor response to be 0.809 and 0.798, respectively, better than either CRAFITY score (0.771 & 0.750) or AFP response at 6 weeks (0.725 & 0.680) alone. In conclusions, the CAR classification which combining CRAFITY score and AFP response at 6 weeks provides a practical guidance for atezolizumab plus bevacizumab therapy in unresectable HCC patients., Competing Interests: None., (AJCR Copyright © 2022.)
- Published
- 2022
35. Appropriateness, endoscopic findings and contributive yield of pediatric gastrointestinal endoscopy.
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Lee WS, Zainuddin H, Boey CC, and Chai PF
- Subjects
- Adolescent, Age Factors, Child, Child, Preschool, Colonoscopy, Female, Gastrointestinal Diseases therapy, Humans, Infant, Malaysia, Male, Predictive Value of Tests, Prognosis, Retrospective Studies, Unnecessary Procedures, Endoscopy, Gastrointestinal adverse effects, Gastrointestinal Diseases pathology, Patient Selection
- Abstract
Aim: To determine the predictability of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) and American Society for Gastrointestinal Endoscopy (ASGE) guideline with regard to appropriate endoscopic practice in children, positive endoscopic findings and contributive yield in clinical practice., Methods: This was a descriptive, retrospective analysis, conducted at the Department of Paediatrics, University Malaya Medical Centre, Malaysia. All children who had esophagogastroduodenoscopy (EGD) and colonoscopy from January 2008 to June 2011 were included. An endoscopy was considered appropriate when its indication complied with the NASPGHAN and ASGE guideline. All endoscopic findings were classified as either positive (presence of any endoscopic or histologic abnormality) or negative (no or minor abnormality, normal histology); effecting a positive contributive (a change in therapeutic decisions or prognostic consequences) or non-contributive yield (no therapeutic or prognostic consequences)., Results: Overall, 76% of the 345 procedures (231 EGD alone, 26 colonoscopy alone, 44 combined EGD and colonoscopy) performed in 301 children (median age 7.0 years, range 3 months to 18 years) had a positive endoscopic finding. Based on the NASPGHAN and ASGE guideline, 99.7% of the procedures performed were considered as appropriate. The only inappropriate procedure (0.3%) was in a child who had EGD for assessment of the healing of gastric ulcer following therapy in the absence of any symptoms. The overall positive contributive yield for a change in diagnosis and/or management was 44%. The presence of a positive endoscopic finding was more likely to effect a change in the therapeutic plan than an alteration of the initial diagnosis. A total of 20 (5.8%) adverse events were noted, most were minor and none was fatal., Conclusion: The NASPGHAN and ASGE guideline is more likely to predict a positive endoscopic finding but is less sensitive to effect a change in the initial clinical diagnosis or the subsequent therapeutic plan.
- Published
- 2013
- Full Text
- View/download PDF
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