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1.
Sensors (Basel) ; 23(20)2023 Oct 21.
Article in English | MEDLINE | ID: mdl-37896715

ABSTRACT

Hyperspectral imagers, or imaging spectrometers, are used in many remote sensing environmental studies in fields such as agriculture, forestry, geology, and hydrology. In recent years, compact hyperspectral imagers were developed using commercial-off-the-shelf components, but there are not yet any off-the-shelf data acquisition systems on the market to deploy them. The lack of a self-contained data acquisition system with navigation sensors is a challenge that needs to be overcome to successfully deploy these sensors on remote platforms such as drones and aircraft. Our work is the first successful attempt to deploy an entirely open-source system that is able to collect hyperspectral and navigation data concurrently for direct georeferencing. In this paper, we describe a low-cost, lightweight, and deployable data acquisition device for the open-source hyperspectral imager (OpenHSI). We utilised commercial-off-the-shelf hardware and open-source software to create a compact data acquisition device that can be easily transported and deployed. The device includes a microcontroller and a custom-designed PCB board to interface with ancillary sensors and a Raspberry Pi 4B/NVIDIA Jetson. We demonstrated our data acquisition system on a Matrice M600 drone at a beach in Sydney, Australia, collecting timestamped hyperspectral, navigation, and orientation data in parallel. Using the navigation and orientation data, the hyperspectral data were georeferenced. While the entire system including the pushbroom hyperspectral imager and housing weighed 735 g, it was designed to be easy to assemble and modify. This low-cost, customisable, deployable data acquisition system provides a cost-effective solution for the remote sensing of hyperspectral data for everyone.

2.
Malays Orthop J ; 17(1): 142-148, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37064641

ABSTRACT

Introduction: Current literature reports varied significance of ulnar styloid fractures (USF) associated with distal radius fractures. Our study assesses the role of ulnar styloid fractures and fragment size in surgically managed distal radius fractures. Materials and methods: We reviewed patients who underwent surgical fixation of distal radius fractures between January 2004 to June 2006. Patients were divided into those with (Group 1) and without (Group 0) USFs. Post-operative radiographic parameters, clinical outcomes and overall wrist function were analysed. Outcomes included ulnar-sided wrist pain, extensor carpi ulnaris (ECU) tendinitis, triangular fibrocartilage complex (TFCC) grind test, distal radioulnar joint (DRUJ) instability and pain. Overall wrist function was assessed with range of motion and Disabilities of the Arm, Shoulder and Hand (DASH) score. Results: Our study cohort included 31 males and 23 females, and 38.9% of these patients had concomitant USFs. There was no difference in terms of demographic data and fracture configuration between groups. Radiographic parameters were similar, except for palmar tilt, which was significantly higher in Group 1 (4.6º vs 9.4º, p=0.047). At 24 months, there were no differences in clinical outcomes and overall wrist function. A sub-group analysis showed that mean USF fragment size was larger in patients with a positive TFCC grind test (3.9mm vs 7.3mm, p=0.033). Conclusion: The presence of USFs in surgically managed distal radius fractures does not compromise clinical and functional outcome. Similarly, the size of USFs does not impact clinical and functional outcome but is associated with the presence of a positive TFCC grind test.

3.
Hong Kong Med J ; 28(6): 447-456, 2022 12.
Article in English | MEDLINE | ID: mdl-36423912

ABSTRACT

INTRODUCTION: This retrospective study was conducted to identify the characteristics of paediatric high-grade osteosarcoma and define its prognostic factors. METHODS: We identified paediatric patients (aged <19 years at diagnosis) diagnosed with high-grade osteosarcoma from 1 January 2009 to 31 December 2018 in two hospitals in Hong Kong, then retrospectively evaluated their medical records to identify prognostic factors. RESULTS: In total, 52 patients were included in this study (22 girls, 42.3%). Femoral tumour was the most common form of osteosarcoma. Most patients (78.8%) had localised disease at diagnosis. The lung was the most common site of metastasis. Almost half (n=23, 46.9%) of the patients showed a good response to chemotherapy (ie, chemonecrosis >90%). Most patients (n=40, 80%) underwent limb-salvage surgery. The event-free survival and overall survival rates were 55.8% and 71.2%, respectively. Prognostic factors independently associated with poor event-free survival and poor overall survival were the presence of metastasis at diagnosis, poor tumour chemonecrosis, and the need for amputation. CONCLUSION: This multicentre review of paediatric high-grade osteosarcoma showed that the baseline patient demographics, event-free survival, and overall survival in Hong Kong were similar to previous findings in other countries. Patients with metastatic disease at diagnosis and poor chemonecrosis had worse survival outcomes. Molecular analyses of genetic abnormalities may help to identify targeted therapies in future studies.


Subject(s)
Bone Neoplasms , Osteosarcoma , Female , Child , Humans , Retrospective Studies , Bone Neoplasms/pathology , Prognosis , Osteosarcoma/drug therapy , Osteosarcoma/pathology , Survival Rate
4.
Ann Oncol ; 33(8): 794-803, 2022 08.
Article in English | MEDLINE | ID: mdl-35491007

ABSTRACT

BACKGROUND: Quantitative measurement of plasma Epstein-Barr virus (EBV) DNA by real-time PCR at the end of primary treatment is a robust prognostic marker for nasopharyngeal carcinoma (NPC) patients. However, up to 40% of patients who would later develop disease recurrence had undetectable post-treatment plasma EBV DNA. Targeted sequencing for the entire EBV genome potentially allows a more comprehensive and unbiased detection of plasma EBV DNA and enables the use of other parameters such as fragment size as biomarkers. Hence, we explored if plasma EBV DNA sequencing might allow more accurate prognostication of NPC patients. PATIENTS AND METHODS: Plasma samples collected from 769 patients with stage IIB-IVB NPC at 6-8 weeks after radiotherapy were analysed using targeted sequencing for EBV DNA. RESULTS: The sensitivities of the PCR-based analysis, at a cut-off of any detectable levels of plasma EBV DNA, for prediction of local and distant recurrences were 42.3% and 85.3%, respectively. The sequencing-based analysis (involving quantitation and size profiling) achieved better performance for both local and distant recurrences than PCR. Using a cut-off of the proportion of plasma EBV DNA deduced by sequencing at 0.01%, the sensitivities of the sequencing-based analysis for local and distant recurrences were 88.5% and 97.1%, with the resultant negative predictive values of 99.1% and 99.4%, respectively. Among patients with undetectable EBV DNA on quantitative PCR, sequencing could further define a subgroup that enjoyed superior survival outcomes based on the proportion of plasma EBV DNA, with a 5-year progression-free survival (PFS) approaching 90%. On multivariate analysis, sequencing-based quantitative level of plasma EBV DNA was the independent prognostic factor with the highest hazard ratio for prediction of overall survival and PFS. CONCLUSION: NPC prognostication using post-treatment plasma EBV DNA could be enhanced through sequencing.


Subject(s)
Epstein-Barr Virus Infections , Nasopharyngeal Neoplasms , DNA, Viral/genetics , Herpesvirus 4, Human/genetics , Humans , Nasopharyngeal Carcinoma/pathology , Nasopharyngeal Carcinoma/therapy , Nasopharyngeal Neoplasms/genetics , Nasopharyngeal Neoplasms/pathology , Nasopharyngeal Neoplasms/therapy , Neoplasm Recurrence, Local/genetics , Prognosis , Real-Time Polymerase Chain Reaction , Risk Assessment
7.
Med J Malaysia ; 76(4): 565, 2021 07.
Article in English | MEDLINE | ID: mdl-34305119

ABSTRACT

No abstract provided.


Subject(s)
Electrocardiography , Smartphone , Humans
8.
Trop Biomed ; 38(2): 143-148, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-34172703

ABSTRACT

Normocyte binding protein Xa (NBPXa) has been implied to play a significant role in parasite invasion of human erythrocytes. Previous phylogenetic studies have reported the existence of three types of NBPXa for Plasmodium knowlesi (PkNBPXa). PkNBPXa region II (PkNBPXaII) of type 1, type 2 and type 3 were expressed on mammalian cell surface and interacted with human and macaque (Macaca fascicularis) erythrocytes. The binding activities of PkNBPXaII towards human and macaque erythrocytes were evaluated using erythrocyte-binding assay (EBA). Three parameters were evaluated to achieve the optimal protein expression of PkNBPXaII and erythrocyte binding activity in EBA: types of mammalian cells, post transfection time and erythrocyte incubation time. COS-7, HEK-293, and CHO-K1 cells showed successful expression of PkNBPXaII, despite the protein expression is weak compared to the positive control. COS-7 was used in EBA. All three types of PkNBPXaII showed rosette formation with macaque erythrocytes but not with human erythrocytes. Future studies to enhance the PkNBPXaII expression on surface of mammalian cells is indeed needed in order to elucidate the specific role of PkNBPXaII in erythrocytes invasion.


Subject(s)
Erythrocytes/parasitology , Membrane Proteins/metabolism , Plasmodium knowlesi , Protozoan Proteins/metabolism , Animals , Antigens, Protozoan , CHO Cells , COS Cells , Chlorocebus aethiops , Cricetulus , Erythrocytes/metabolism , HEK293 Cells , Humans , Membrane Proteins/genetics , Phylogeny , Plasmodium knowlesi/genetics , Plasmodium knowlesi/metabolism , Protein Binding , Protozoan Proteins/genetics
9.
Tropical Biomedicine ; : 143-148, 2021.
Article in English | WPRIM (Western Pacific) | ID: wpr-904658

ABSTRACT

@# Normocyte binding protein Xa (NBPXa) has been implied to play a significant role in parasite invasion of human erythrocytes. Previous phylogenetic studies have reported the existence of three types of NBPXa for Plasmodium knowlesi (PkNBPXa). PkNBPXa region II (PkNBPXaII) of type 1, type 2 and type 3 were expressed on mammalian cell surface and interacted with human and macaque (Macaca fascicularis) erythrocytes. The binding activities of PkNBPXaII towards human and macaque erythrocytes were evaluated using erythrocyte-binding assay (EBA). Three parameters were evaluated to achieve the optimal protein expression of PkNBPXaII and erythrocyte binding activity in EBA: types of mammalian cells, post transfection time and erythrocyte incubation time. COS-7, HEK-293, and CHO-K1 cells showed successful expression of PkNBPXaII, despite the protein expression is weak compared to the positive control. COS-7 was used in EBA. All three types of PkNBPXaII showed rosette formation with macaque erythrocytes but not with human erythrocytes. Future studies to enhance the PkNBPXaII expression on surface of mammalian cells is indeed needed in order to elucidate the specific role of PkNBPXaII in erythrocytes invasion.

11.
Ann Oncol ; 31(6): 769-779, 2020 06.
Article in English | MEDLINE | ID: mdl-32217076

ABSTRACT

BACKGROUND: After curative radiotherapy (RT) or chemoradiation (CRT), there is no validated tool to accurately identify patients for adjuvant therapy in nasopharyngeal carcinoma (NPC). Post-RT circulating plasma Epstein-Barr virus (EBV) DNA can detect minimal residual disease and is associated with recurrence and survival independent of TNM (tumor-lymph node-metastasis) stage. We aimed to develop and validate a risk model for stratification of NPC patients after completion of RT/CRT to observation or adjuvant therapy. PATIENTS AND METHODS: The prospective multicenter 0502 EBV DNA screening cohort (Hong Kong NPC Study Group 0502 trial) enrolled from 2006 to 2015 (n = 745) was used for model development. For internal validation, we pooled independent patient cohorts from prospective clinical studies enrolled from 1997 to 2006 (n = 340). For external validation, we used retrospective cohort of NPC patients treated at Sun Yat-sen University Cancer Center from 2009 to 2012 (n = 837). Eligible patients had histologically confirmed NPC of Union for International Cancer Control (UICC) 7th Edition stage II-IVB who completed curative RT/CRT with or without neoadjuvant chemotherapy, had post-RT EBV DNA tested within 120 days after RT and received no adjuvant therapy. The primary end point was overall survival (OS). We used recursive-partitioning analysis (RPA) to classify patients into groups of low, intermediate, and high risk of death. RESULTS: Combining post-RT EBV DNA level (0, 1-49, 50-499, and ≥500 copies/ml) and TNM stage (II, III, IVAB), RPA model classified patients into low-, intermediate-, and high-risk groups with 5-year OS of 89.4%, 78.5% and 37.2%, respectively. The RPA low-risk group had comparable OS to TNM stage II (5-year OS 88.5%) but identified more patients (64.8% versus stage II 28.1%) that could potentially be spared adjuvant therapy toxicity. The RPA model (c-index 0.712) showed better risk discrimination than either the TNM stage (0.604) or post-RT EBV DNA alone (0.675) with improved calibration and consistence. These results were validated in both internal and external cohorts. CONCLUSION: Combining post-RT EBV DNA and TNM stage improved risk stratification in NPC.


Subject(s)
Epstein-Barr Virus Infections , Nasopharyngeal Neoplasms , DNA, Viral/genetics , Epstein-Barr Virus Infections/pathology , Herpesvirus 4, Human/genetics , Humans , Nasopharyngeal Carcinoma/therapy , Nasopharyngeal Neoplasms/radiotherapy , Neoplasm Recurrence, Local , Neoplasm Staging , Plasma , Prognosis , Prospective Studies , Retrospective Studies , Risk Assessment
13.
AMIA Annu Symp Proc ; 2020: 1190-1199, 2020.
Article in English | MEDLINE | ID: mdl-33936495

ABSTRACT

Chest radiographs are the most common diagnostic exam in emergency rooms and intensive care units today. Recently, a number of researchers have begun working on large chest X-ray datasets to develop deep learning models for recognition of a handful of coarse finding classes such as opacities, masses and nodules. In this paper, we focus on extracting and learning fine-grained labels for chest X-ray images. Specifically we develop a new method of extracting fine-grained labels from radiology reports by combining vocabulary-driven concept extraction with phrasal grouping in dependency parse trees for association of modifiers with findings. A total of457finegrained labels depicting the largest spectrum of findings to date were selected and sufficiently large datasets acquired to train a new deep learning model designed for fine-grained classification. We show results that indicate a highly accurate label extraction process and a reliable learning of fine-grained labels. The resulting network, to our knowledge, is the first to recognize fine-grained descriptions offindings in images covering over nine modifiers including laterality, location, severity, size and appearance.


Subject(s)
Diagnosis, Computer-Assisted/methods , Machine Learning , Neural Networks, Computer , Radiographic Image Interpretation, Computer-Assisted/methods , Radiography, Thoracic/methods , Deep Learning , Humans , Pattern Recognition, Automated , Thorax/diagnostic imaging
15.
Clin Oncol (R Coll Radiol) ; 31(2): e11-e20, 2019 02.
Article in English | MEDLINE | ID: mdl-30454940

ABSTRACT

AIMS: Recently published international guidelines recommended using the stimulated thyroglobulin (sTg) post-radioactive iodine (RAI) ablation, in conjunction with tumour stage, as a risk stratification factor. The choice of cut-off values for sTg, namely 1 and 10 ng/ml, was, however, largely based on the functional sensitivities of the assays used, with relatively few published data addressing the prognostic impact of alternative cut-off values. Our study aims to provide data on the prognostic value of sTg at different levels of sensitivities and specificities. MATERIALS AND METHODS: We conducted a retrospective review of all adult cases of differentiated thyroid carcinoma receiving RAI ablation at our centre from 2008 to 2010. All patients had sTg measured at around 6 months post-ablation. The functional sensitivity of our assay was 0.5 ng/ml. The outcome was adverse clinical event, defined as cancer-related death, persistent macroscopic disease demonstrable on imaging (including radioisotope scan) and/or receiving further treatment for persistent or recurrent disease. A receiver operating characteristic (ROC) analysis was carried out. RESULTS: We identified 140 patients treated in the review period, with 106 of them suitable for further analysis. The reasons for exclusion included the presence of anti-thyroglobulin antibodies and medullary or anaplastic histological subtypes. Most (54.7%) had intermediate-risk disease as per the American Thyroid Association classification (2009). The median follow-up duration was 6.4 years; the minimum, excluding deaths, was 5.0 years. ROC analysis showed that the optimal cut-off value of sTg for predicting adverse clinical events was >1.0 ng/ml, associated with a sensitivity of 90.9%, a specificity of 81.0%, a positive predictive value of 55.6% and a negative predictive value of 97.1%. CONCLUSION: Based on ROC analysis of sensitivities and specificities, our data showed that a post-ablation sTg value of 1 ng/ml is the optimal cut-off in prognostication of adverse clinical events.


Subject(s)
Thyroglobulin/therapeutic use , Thyroid Neoplasms/blood , Thyroid Neoplasms/diagnosis , Adult , Aged , Female , Humans , Male , Middle Aged , Prognosis , Retrospective Studies , Risk Factors , Thyroglobulin/pharmacology , Thyroid Neoplasms/pathology
17.
N Z Med J ; 129(1431): 51-8, 2016 Mar 11.
Article in English | MEDLINE | ID: mdl-27005874

ABSTRACT

AIMS: To explore health problems and the accessing of health services by frequent legal high users under an interim regulated legal market in central Auckland. METHOD: Frequent legal high users (monthly+) were recruited from outside eight randomly-selected, licensed, legal high stores in central Auckland from 23 April-7 May, 2014. Eligible participants were emailed a unique invitation to complete an on-line survey; 105 completed the survey. RESULTS: Twenty-seven percent had suffered mental illness during their lifetimes. Eighty percent used synthetic cannabinoids (SC), and 20% 'party pills'. Forty-seven percent of SC users used daily or more often. Other drugs used included alcohol (80%), cannabis (59%), 'ecstasy' (18%) and methamphetamine (15%). Fifty-eight percent of SC users were classified as SC dependent. The most common problems reported from SC use were: insomnia (29%); 'vomiting/nausea' (25%); 'short temper/agitation' (21%); 'anxiety' (21%); 'strange thoughts' (16%); and 'heart palpitations' (14%). The health services most commonly accessed by SC users were: a 'doctor/GP' (9%); 'counsellor' (9%); 'DrugHelp/MethHelp' websites (7%); 'Alcohol & Drug Helpline' (4%); 'ambulance' (3%); 'A&E' (3%); and hospitalisation (3%). CONCLUSIONS: Frequent use of interim licensed SC products was associated with health problems, including dependency. Further research is required to determine the health risks of these products.


Subject(s)
Anxiety/epidemiology , Cannabinoids , Drug and Narcotic Control , Health Services/statistics & numerical data , Illicit Drugs/legislation & jurisprudence , Nausea/epidemiology , Seizures/epidemiology , Substance-Related Disorders/epidemiology , Vomiting/epidemiology , Adolescent , Adult , Female , Help-Seeking Behavior , Humans , Male , Mental Disorders/epidemiology , Middle Aged , New Zealand/epidemiology , Self Report , Suicidal Ideation , Weight Loss , Young Adult
18.
Eur J Vasc Endovasc Surg ; 51(3): 441-51, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26684597

ABSTRACT

BACKGROUND: Simulation training in endovascular surgery provides opportunities for trainees to practice and learn from non-patient based experience. Several types of endovascular simulators are available commercially. Previous studies on endovascular simulation training can be categorized into trials in which only a simulator was used when measuring performance metrics or "trials within simulation"; patient specific procedure rehearsals; and randomized, controlled trials (RCTs) or translational studies. OBJECTIVES: To examine whether endovascular simulation training can improve surgeon techniques and patient outcomes in real clinical settings. METHODS: A literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. All searches were done via PubMed and Embase. Review articles, and papers that were not related to endovascular surgery and not within the scope of interest were excluded. References of review articles were further screened according to the exclusion criteria. RESULTS: In total, 909 records were identified and 290 duplicates were removed. Thirty-one were included in the qualitative analysis. Twenty-three were trials within simulation and most of them found statistically significant improvements in procedure time, fluoroscopy time, and contrast volume. Five were patient specific procedure rehearsals and showed that simulation significantly affected the fluoroscopy angle and improved performance metrics. Three were RCTs and revealed mainly positive results on a Global Rating Scale and procedure specific rating scale. CONCLUSIONS: Contemporary evidence shows that performance metrics within endovascular simulations improve with simulation training. Successful translation to in vivo situations is observed in patient specific procedure rehearsals and RCTs on real procedures. However, there is no level I evidence to show that predictive validity of simulation can definitively improve patient outcomes. Current literature supports the idea that there is a beneficial role of simulation in endovascular training. Future studies are needed to confirm the efficacy of simulation in endovascular surgical training and to see if simulation is superior to traditional training in the operating theatre.


Subject(s)
Computer Simulation , Education, Medical, Continuing/methods , Endovascular Procedures/education , Clinical Competence , Humans
19.
Comput Aided Surg ; 20(1): 14-23, 2015.
Article in English | MEDLINE | ID: mdl-26290317

ABSTRACT

Resection of a pelvic tumor is challenging because of its complex three-dimensional (3D) anatomy and deep-seated location with nearby vital structures. The resection is technically demanding if a custom implant is used for reconstruction of the bone defect as the surgeon needs to ensure the resection margin is sufficiently wide and the orientation of intended resection planes must match that of the custom implant. We describe a novel workflow of performing a partial acetabular resection in a patient with pelvic chondrosarcoma and reconstruction with a custom pelvic implant in a one-step operation. A multi-planar bone resection was virtually planned. A computer-aided design implant that both matched the bone defect and biomechanically evaluated was prefabricated with 3D printing technology. The 3D-printed patient-specific instruments (PSIs) were used to reproduce the same planned resection. The histology of the tumor specimen showed a clear resection margin. The errors of the achieved resection and implant position were deviating (1-4 mm) from the planned. The patient could walk unaided with a good hip function. No tumor recurrence and implant loosening were noted at 11 months after surgery. The use of this novel CT-based method for surgical planning, the engineering software for implant design and validation, together with 3D printing technology for implant and PSI fabrication makes it possible to generate a personalized, biomechanically evaluated implant for accurate reconstruction after a pelvic tumor resection in a one-step operation. Further study in a larger population is needed to assess the clinical efficacy of the workflow in complex bone tumor surgery.


Subject(s)
Bone Neoplasms/surgery , Imaging, Three-Dimensional/methods , Orthopedic Procedures/methods , Pelvic Bones/surgery , Printing, Three-Dimensional , Prostheses and Implants , Surgery, Computer-Assisted/methods , Aged , Biomechanical Phenomena , Bone Neoplasms/diagnosis , Computer-Aided Design , Humans , Magnetic Resonance Imaging , Male , Prosthesis Design , Tomography, X-Ray Computed
20.
Hong Kong Med J ; 21(1): 69-72, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25686705

ABSTRACT

Xanthogranulomatous inflammation is a rare pathological condition most frequently detected in the kidney and gallbladder. Reported herein is a case of xanthogranulomatous inflammation in a 51-year-old male presenting as a mass-forming lesion in the terminal ileum with mucosal ulceration. Diagnostic laparoscopy followed by ileocecectomy was performed due to intra-operative suspicion of carcinoma of appendix. This is a report of the condition involving the terminal ileum with mucosal ulceration and full-thickness involvement of bowel wall which are uncommon features of xanthogranulomatous inflammation in previously reported lower gastro-intestinal tract lesions.


Subject(s)
Granuloma/pathology , Ileitis/pathology , Xanthomatosis/pathology , Diagnosis, Differential , Humans , Male , Middle Aged
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