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Lam RPK, Hung KKC, Lui CT, Kwok WS, Lam WWT, Lau EHY, Sridhar S, Ng PYT, Cheng CH, Tsang TC, Tsui MSH, Graham CA, Rainer TH. Early sepsis care with the National Early Warning Score 2-guided Sepsis Hour-1 Bundle in the emergency department: hybrid type 1 effectiveness-implementation pilot stepped wedge randomised controlled trial (NEWS-1 TRIPS) protocol. BMJ Open 2024; 14:e080676. [PMID: 38307529 PMCID: PMC10836386 DOI: 10.1136/bmjopen-2023-080676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 01/24/2024] [Indexed: 02/04/2024] Open
Abstract
INTRODUCTION Early sepsis treatment in the emergency department (ED) is crucial to improve patient survival. Despite international promulgation, the uptake of the Surviving Sepsis Campaign (SSC) Hour-1 Bundle (lactate measurement, blood culture, broad-spectrum antibiotics, 30 mL/kg crystalloid for hypotension/lactate ≥4 mmol/L and vasopressors for hypotension during/after fluid resuscitation within 1 hour of sepsis recognition) is low across healthcare settings. Delays in sepsis recognition and a lack of high-quality evidence hinder its implementation. We propose a novel sepsis care model (National Early Warning Score, NEWS-1 care), in which the SSC Hour-1 Bundle is triggered objectively by a high NEWS-2 (≥5). This study aims to determine the feasibility of a full-scale type 1 hybrid effectiveness-implementation trial on the NEWS-1 care in multiple EDs. METHODS AND ANALYSIS We will conduct a pilot type 1 hybrid trial and prospectively recruit 200 patients from 4 public EDs in Hong Kong cluster randomised in a stepped wedge design over 10 months. All study sites will start with an initial period of standard care and switch in random order at 2-month intervals to the NEWS-1 care unidirectionally. The implementation evaluation will employ mixed methods guided by the Reach, Effectiveness, Adoption, Implementation and Maintenance framework, which includes qualitative and quantitative data from focus group interviews, staff survey and clinical record reviews. We will analyse the 14 feasibility outcomes as progression criteria to a full-scale trial, including trial acceptability to patients and staff, patient and staff recruitment rates, accuracy of sepsis screening, protocol adherence, accessibility to follow-up data, safety and preliminary clinical impacts of the NEWS1 care, using descriptive statistics. ETHICS AND DISSEMINATION The institutional review boards of all study sites approved this study. This study will establish the feasibility of a full-scale hybrid trial. We will disseminate the findings through peer-reviewed publications, conference presentations and educational activities. TRIAL REGISTRATION NUMBER NCT05731349.
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Affiliation(s)
- Rex Pui Kin Lam
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Accident and Emergency Department, Queen Mary Hospital, Hospital Authority, Hong Kong, China
| | - Kevin Kei Ching Hung
- Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong, China
- Accident and Emergency Department, Prince of Wales Hospital, Hospital Authority, Hong Kong, China
| | - Chun Tat Lui
- Accident and Emergency Department, Tuen Mun Hospital, Hospital Authority, Hong Kong, China
| | - Wai Shing Kwok
- Accident and Emergency Department, Pamela Youde Nethersole Eastern Hospital, Hospital Authority, Hong Kong, China
| | - Wendy Wing Tak Lam
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Eric Ho Yin Lau
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Siddharth Sridhar
- Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Peter Yau Tak Ng
- Accident and Emergency Department, Tuen Mun Hospital, Hospital Authority, Hong Kong, China
| | - Chi Hung Cheng
- Accident and Emergency Department, Prince of Wales Hospital, Hospital Authority, Hong Kong, China
| | - Tat Chi Tsang
- Accident and Emergency Department, Queen Mary Hospital, Hospital Authority, Hong Kong, China
| | - Matthew Sik Hon Tsui
- Accident and Emergency Department, Queen Mary Hospital, Hospital Authority, Hong Kong, China
| | - Colin Alexander Graham
- Accident and Emergency Medicine Academic Unit, The Chinese University of Hong Kong, Hong Kong, China
- Accident and Emergency Department, Prince of Wales Hospital, Hospital Authority, Hong Kong, China
| | - Timothy Hudson Rainer
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
- Accident and Emergency Department, Queen Mary Hospital, Hospital Authority, Hong Kong, China
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Wong BPK, Lam RPK, Ip CYT, Chan HC, Zhao L, Lau MCK, Tsang TC, Tsui MSH, Rainer TH. Applying artificial neural network in predicting sepsis mortality in the emergency department based on clinical features and complete blood count parameters. Sci Rep 2023; 13:21463. [PMID: 38052864 PMCID: PMC10698015 DOI: 10.1038/s41598-023-48797-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 11/30/2023] [Indexed: 12/07/2023] Open
Abstract
A complete blood count (CBC) is routinely ordered for emergency department (ED) patients with infections. Certain parameters, such as the neutrophil-to-lymphocyte ratio (NLR), might have prognostic value. We aimed to evaluate the prognostic value of the presenting CBC parameters combined with clinical variables in predicting 30-day mortality in adult ED patients with infections using an artificial neural network (ANN). We conducted a retrospective study of ED patients with infections between 17 December 2021 and 16 February 2022. Clinical variables and CBC parameters were collected from patient records, with NLR, monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) calculated. We determined the discriminatory performance using the area under the receiver operating characteristic curve (AUROC) and performed a 70/30 random data split and supervised ANN machine learning. We analyzed 558 patients, of whom 144 (25.8%) had sepsis and 60 (10.8%) died at 30 days. The AUROCs of NLR, MLR, PLR, and their sum were 0.644 (95% CI 0.573-0.716), 0.555 (95% CI 0.482-0.628), 0.606 (95% CI 0.529-0.682), and 0.610 (95% CI 0.534-0.686), respectively. The ANN model based on twelve variables including clinical variables, hemoglobin, red cell distribution width, NLR, and PLR achieved an AUROC of 0.811 in the testing dataset.
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Affiliation(s)
- Beata Pui Kwan Wong
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Rex Pui Kin Lam
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
| | - Carrie Yuen Ting Ip
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Ho Ching Chan
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Lingyun Zhao
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Michael Chun Kai Lau
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Tat Chi Tsang
- Accident and Emergency Department, Queen Mary Hospital, Hospital Authority, Hong Kong Special Administrative Region, China
| | - Matthew Sik Hon Tsui
- Accident and Emergency Department, Queen Mary Hospital, Hospital Authority, Hong Kong Special Administrative Region, China
| | - Timothy Hudson Rainer
- Department of Emergency Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
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Yan VKC, Wan EYF, Ye X, Mok AHY, Lai FTT, Chui CSL, Li X, Wong CKH, Li PH, Ma T, Qin S, Wong VKC, Tsang TC, Tsui SH, Chui WCM, Cowling BJ, Leung GM, Lau CS, Wong ICK, Chan EWY. Effectiveness of BNT162b2 and CoronaVac vaccinations against mortality and severe complications after SARS-CoV-2 Omicron BA.2 infection: a case-control study. Emerg Microbes Infect 2022; 11:2304-2314. [PMID: 35980089 PMCID: PMC9553171 DOI: 10.1080/22221751.2022.2114854] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Data regarding protection against mortality and severe complications after Omicron BA.2 infection with CoronaVac and BNT162b2 vaccines remains limited. We conducted a case–control study to evaluate the risk of severe complications and mortality following 1–3 doses of CoronaVac and BNT162b2 using electronic health records database. Cases were adults with their first COVID-19-related mortality or severe complications between 1 January and 31 March 2022, matched with up-to 10 controls by age, sex, index date, and Charlson Comorbidity Index. Vaccine effectiveness against COVID-19-related mortality and severe complications by type and number of doses was estimated using conditional logistic regression adjusted for comorbidities and medications. Vaccine effectiveness (95% CI) against COVID-19-related mortality after two doses of BNT162b2 and CoronaVac were 90.7% (88.6–92.3) and 74.8% (72.5–76.9) in those aged ≥65, 87.6% (81.4–91.8) and 80.7% (72.8–86.3) in those aged 50–64, 86.6% (71.0–93.8) and 82.7% (56.5–93.1) in those aged 18–50. Vaccine effectiveness against severe complications after two doses of BNT162b2 and CoronaVac were 82.1% (74.6–87.3) and 58.9% (50.3–66.1) in those aged ≥65, 83.0% (69.6–90.5) and 67.1% (47.1–79.6) in those aged 50–64, 78.3% (60.8–88.0) and 77.8% (49.6–90.2) in those aged 18–50. Further risk reduction with the third dose was observed especially in those aged ≥65 years, with vaccine effectiveness of 98.0% (96.5–98.9) for BNT162b2 and 95.5% (93.7–96.8) for CoronaVac against mortality, 90.8% (83.4–94.9) and 88.0% (80.8–92.5) against severe complications. Both CoronaVac and BNT162b2 vaccination were effective against COVID-19-related mortality and severe complications amidst the Omicron BA.2 pandemic, and risks decreased further with the third dose.
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Affiliation(s)
- Vincent Ka Chun Yan
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Eric Yuk Fai Wan
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,Laboratory of Data Discovery for Health (D24H), Hong Kong Science and Technology Park, Hong Kong China.,Department of Family Medicine and Primary Care, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Xuxiao Ye
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Anna Hoi Ying Mok
- Department of Family Medicine and Primary Care, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Francisco Tsz Tsun Lai
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China
| | - Celine Sze Ling Chui
- Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China.,School of Nursing, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Xue Li
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China.,Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Carlos King Ho Wong
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China.,Department of Family Medicine and Primary Care, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Philip Hei Li
- Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Tiantian Ma
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China
| | - Simon Qin
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China
| | | | - Tat Chi Tsang
- Department of Accident and Emergency, Queen Mary Hospital, Hong Kong China
| | - Sik Hon Tsui
- Department of Accident and Emergency, Queen Mary Hospital, Hong Kong China
| | | | - Benjamin John Cowling
- Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China.,World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Gabriel Matthew Leung
- Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China.,World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Chak Sing Lau
- Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China
| | - Ian Chi Kei Wong
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China.,Research Department of Practice and Policy, School of Pharmacy, University College London, London, United Kingdom.,Aston Pharmacy School, Aston University, Birmingham, B4 7ET, UK.,Department of Pharmacy, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - Esther Wai Yin Chan
- Centre for Safe Medication Practice and research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong China.,Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong China.,Department of Pharmacy, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
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Leung WCY, Teo KC, Kwok WM, Lam LHC, Choi OMY, Tse MMY, Lui WM, Tsang TC, Tsang ACO. Pre-hospital stroke screening and notification of patients with reperfusion-eligible acute ischaemic stroke using modified Face Arm Speech Time test. Hong Kong Med J 2020; 26:479-485. [PMID: 33284132 DOI: 10.12809/hkmj208552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES To investigate the effects of pre-hospital stroke screening and notification on reperfusion therapy for patients with acute ischaemic stroke. METHODS Pre-hospital stroke screening criteria were established based on a modified version of the Face Arm Speech Time (FAST) test. Screening was performed during ambulance transport by emergency medical service (EMS) personnel who completed a 2-hour training session on stroke screening. Temporal trends affecting acute ischaemic stroke investigation and intervention were compared before and after implementation of the pre-hospital screening. RESULTS From July 2018 to October 2019, 298 patients with suspected stroke were screened by EMS personnel during ambulance transport prior to hospital arrival. Of these 298 patients, 213 fulfilled the screening criteria, 166 were diagnosed with acute stroke, and 32 received reperfusion therapy. The onset-to-door time was shortened by more than 1.5 hours (100.6 min vs 197.6 min, P<0.001). The door-to-computed tomography time (25.6 min vs 32.0 min, P=0.021), door-to-needle time (49.2 min vs 70.1 min, P=0.003), and door-to-groin puncture time for intra-arterial mechanical thrombectomy (126.7 min vs 168.6 min, P=0.04) were significantly shortened after implementation of the pre-hospital screening and notification, compared with historical control data of patients admitted from January 2018 to June 2018, before implementation of the screening system. CONCLUSION Implementation of pre-hospital stroke screening using criteria based on a modified version of the FAST test, together with pre-arrival notification, significantly shortened the door-to-reperfusion therapy time for patients with ischaemic stroke. Pre-hospital stroke screening during ambulance transport by EMS personnel who complete a 2-hour focused training session is effective for identifying reperfusion-eligible patients with stroke.
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Affiliation(s)
- W C Y Leung
- Division of Neurology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong
| | - K C Teo
- Division of Neurology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong
| | - W M Kwok
- Department of Accident and Emergency, Queen Mary Hospital, Hong Kong
| | - L H C Lam
- Hong Kong Division, Ambulance Command, Hong Kong Fire Services Department, Hong Kong
| | - O M Y Choi
- Division of Neurosurgery, Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Hong Kong
| | - M M Y Tse
- Division of Neurology, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong
| | - W M Lui
- Division of Neurosurgery, Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Hong Kong
| | - T C Tsang
- Department of Accident and Emergency, Queen Mary Hospital, Hong Kong
| | - A C O Tsang
- Division of Neurosurgery, Department of Surgery, Queen Mary Hospital, The University of Hong Kong, Hong Kong
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Lam RPK, Wong RTM, Lau EHY, Wong KW, Cheung ACK, Chaang VK, Chen L, Tsang TC, Chan TK, Chee PPY, Ko FHF, Leung CS, Yang SM. Injury patterns of mass casualty incidents involving high-speed passenger ferries presenting to accident and emergency departments in Hong Kong: a retrospective review. Injury 2020; 51:252-259. [PMID: 31836173 DOI: 10.1016/j.injury.2019.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 12/01/2019] [Indexed: 02/02/2023]
Abstract
BACKGROUND Accidents involving high-speed passenger ferries have the potential to cause mass-casualty incidents (MCIs), yet there is a lack of relevant studies available to inform hospital disaster preparedness planning. OBJECTIVE The objective was to study the injury patterns and outcomes of MCI victims involved in high-speed passenger ferry accidents in Hong Kong waters. METHODS A retrospective study was conducted from 1 January 2005 to 31 December 2015. All MCIs involving high-speed passenger ferries were captured from the Marine Department of Hong Kong. Victims of all age who were sent to the accident and emergency departments (A&Es) of seven public hospitals around Victoria Harbour, including three trauma centres, were identified from electronic disaster registries of the study hospitals. Data on injury patterns and outcomes were extracted from medical records with the Injury Severity Score (ISS) calculated for each victim. The Kruskal-Wallis test was used to compare medians of the ISS across different mechanisms of injury. Multivariable logistic regression was performed to identify independent predictors for major trauma (ISS≥16). RESULTS During the study period, eight MCIs involving high-speed passenger ferries were reported and 512 victims (median age: 44 years, age range: 2-85 years) were sent to the study hospitals. The A&E triage categories were Cat 1, 3.1%; Cat 2, 4.3%; Cat 3, 19.3%; Cat 4, 72.9%; and Cat 5, 0.4%, respectively. The median ISS was 1.0 (interquartile range: 1.0-2.0). Fourteen victims (2.7%) had an ISS≥16 and age was the only independent predictor for major trauma (OR 1.06, p = 0.025, 95% CI 1.01-1.11). Trauma call was activated at A&E for 11 victims. In total, 100 victims (19.5%) were admitted to the study hospitals, including 19 (3.5%) and 15 (2.9%) who required surgery and intensive care unit stay, respectively. Eleven victims (2.1%) died, mostly due to drowning. CONCLUSION MCIs involving high-speed passenger ferries can result in a sudden surge in demand for both A&E and in-patient care, though the majority of victims may have minor injuries. Better access to lifejackets and mandatory seatbelt use may help to reduce injuries and deaths.
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Affiliation(s)
- Rex Pui Kin Lam
- Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China; Accident and Emergency Department, Queen Mary Hospital, Hong Kong Special Administrative Region, China; Accident and Emergency Department, Pamela Youde Nethersole Eastern Hospital, Hong Kong Special Administrative Region, China.
| | - Ronald Tat Ming Wong
- Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Eric Ho Yin Lau
- School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Kin Wa Wong
- Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China; Accident and Emergency Department, Pamela Youde Nethersole Eastern Hospital, Hong Kong Special Administrative Region, China
| | - Arthur Chi Kin Cheung
- Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Vi Ka Chaang
- Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Lujie Chen
- Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Tat Chi Tsang
- Accident and Emergency Department, Queen Mary Hospital, Hong Kong Special Administrative Region, China
| | - Tak Kuen Chan
- Accident and Emergency Department, Ruttonjee Hospital, Hong Kong Special Administrative Region, China
| | - Peter Pay Yun Chee
- Accident and Emergency Department, St John Hospital, Hong Kong Special Administrative Region, China
| | - Frank Hiu Fai Ko
- Accident and Emergency Department, Queen Elizabeth Hospital, Hong Kong Special Administrative Region, China
| | - Chin San Leung
- Accident and Emergency Department, Princess Margaret Hospital, Hong Kong Special Administrative Region, China
| | - Siu Ming Yang
- Accident and Emergency Department, Kwong Wah Hospital, Hong Kong Special Administrative Region, China
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Cheung KS, Leung LP, Siu YC, Tsang TC, Tsui MSH, Tam CC, Chan RHW. Prehospital electrocardiogram shortens ischaemic time in patients with ST-segment elevation myocardial infarction. Hong Kong Med J 2019; 25:356-362. [PMID: 31619577 DOI: 10.12809/hkmj197995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION Total ischaemic time should be shortened as much as possible in patients with ST-segment elevation myocardial infarction (STEMI). This study evaluated whether prehospital 12-lead electrocardiogram (ECG) could shorten system delay in STEMI management. METHODS From November 2015 to November 2017, 15 ambulances equipped with X Series Monitor/ Defibrillator (Zoll Medical Corporation) were used in the catchment area of Queen Mary Hospital, Hong Kong. Prehospital ECG was performed for patients with chest pain; the data were tele-transmitted to attending emergency physicians at the Accident and Emergency Department (AED) for rapid assessment. Data from patients with STEMI who were transported by these 15 ambulances were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or who used self-arranged transport. RESULTS Data were analysed from 197 patients with STEMI. The median patient delay for activation of the emergency response system was 90 minutes; 12% of patients experienced a delay of >12 hours. There was a significant difference in delay between patients transported by ambulance and those who used self-arranged transport (P<0.001). For system delay, the use of prehospital ECG shortened the median time from ambulance on scene to first ECG (P<0.001). When performed upon ambulance on scene, prehospital ECG was available 5 minutes earlier than if performed in ambulance compartment before departure. Use of prehospital ECG significantly shortened AED door-to-triage time, AED door-to-first AED ECG time, AED door-to-physician consultation time, and length of stay in the AED (P<0.001 for all comparisons). CONCLUSION Prehospital ECG shortened ischaemic time prior to hospital admission.
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Affiliation(s)
- K S Cheung
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - L P Leung
- Emergency Medicine Unit, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Y C Siu
- Fire and Ambulance Services Academy, Hong Kong Fire Services Department, Tseung Kwan O, Hong Kong
| | - T C Tsang
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - M S H Tsui
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - C C Tam
- Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - R H W Chan
- Division of Cardiology, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong
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Cheung KS, Leung LP, Siu YC, Tsang TC, Tsui MS, Tam CC, Chan RH. Prehospital 12-lead electrocardiogram for patients with chest pain: a pilot study. Hong Kong Med J 2018; 24:484-491. [PMID: 30262677 DOI: 10.12809/hkmj177135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION After ST-segment elevation myocardial infarction (STEMI), it is vital to shorten reperfusion time. This study examined data from a pilot project to shorten the door-to-balloon (D2B) time by using prehospital 12-lead electrocardiogram (ECG). METHODS Fifteen ambulances equipped with X Series® Monitor/Defibrillator (Zoll Medical Corporation) were deployed to the catchment area of Queen Mary Hospital, Hong Kong, from November 2015 to December 2016. For patients with chest pain, prehospital 12-lead ECG was performed and tele-transmitted to attending physicians at the accident and emergency department for immediate interpretation. The on-call cardiologist was called before patient arrival if STEMI was suspected. Data from this group of patients with STEMI were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or by self-arranged transport. RESULTS From 841 patients with chest pain, 731 gave verbal consent and prehospital ECG was performed and transmitted. Of these, 25 patients with clinically diagnosed STEMI required emergency coronary angiogram with or without primary percutaneous coronary intervention. The mean D2B time for these 25 patients (93 minutes) was significantly shorter (P=0.003) than that for 58 patients with STEMI transported by ambulances without prehospital ECG (112 minutes) and that for 41 patients with STEMI with self-arranged transport (138 minutes). However, shorter reperfusion time was only recorded during daytime hours (08:00-17:59). No statistically significant difference in 30-day mortality was found. CONCLUSION Prehospital ECG is technologically feasible in Hong Kong and shortens the D2B time. However, shorter reperfusion time was only recorded during daytime hours.
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Affiliation(s)
- K S Cheung
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - L P Leung
- Emergency Medicine Unit, The Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - Y C Siu
- Medical Director, Fire and Ambulance Services Academy, Hong Kong Fire Services Department, Hong Kong
| | - T C Tsang
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - M Sh Tsui
- Department of Accident and Emergency, Queen Mary Hospital, Pokfulam, Hong Kong
| | - C C Tam
- Department of Medicine, Queen Mary Hospital, Pokfulam, Hong Kong
| | - R Hw Chan
- Honorary Consultant Cardiologist, Hong Kong Sanatorium Hospital, Happy Valley, Hong Kong
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Abstract
SummaryA single base pair variation in the coding sequence of
coagulation factor IX produces a protein polymorphism detectable with monoclonal antibodies and a restriction fragment length polymorphism (RFLP). This allows carrier and prenatal diagnoses in 48% of Caucasian families segregating for haemophilia B. However, this RFLP cannot be detected by standard Southern blotting, while the antibody assay may grve equivocal results in some females and can only allow prenatal diagnoses on second trimester fetal blood samples. We show that, using the polymerase chain reaction, the polymorphic DNA segment can be amplified and directly tested for the presence of the alternative sequences by a non-radioactive procedure that has the advantage of speed (1–2 days), partial automation and applicability to first trimester diagnoses. We also show that the method gives results on a single drop of dried blood.
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Affiliation(s)
- T C Tsang
- The Paediatric Research Unit, Division of Medical and Molecular Genetics, United Medical and Dental Schools of Guy’s and St Thomas’s Hospitals, Guy’s Hospital Tower, London, United Kingdom
| | - D R Bentley
- The Paediatric Research Unit, Division of Medical and Molecular Genetics, United Medical and Dental Schools of Guy’s and St Thomas’s Hospitals, Guy’s Hospital Tower, London, United Kingdom
| | - I M Nilsson
- The Department of Coagulation, University Hospital, Malmö, Sweden
| | - F Giannelli
- The Paediatric Research Unit, Division of Medical and Molecular Genetics, United Medical and Dental Schools of Guy’s and St Thomas’s Hospitals, Guy’s Hospital Tower, London, United Kingdom
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9
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Cheung KS, Wong HT, Leung LP, Tsang TC, Leung GKK. Diagnostic accuracy of Focused Abdominal Sonography for Trauma in blunt abdominal trauma patients in a trauma centre of Hong Kong. Chin J Traumatol 2016; 15:273-8. [PMID: 23069097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE Focused Abdominal Sono-graphy for Trauma (FAST) is widely used for the detection of intraperitoneal free fluids in patients suffering from blunt abdominal trauma (BAT). This study aimed at assessing the diagnostic accuracy of this investigation in a designated trauma centre. METHODS This was a retrospective study of BAT patients over a 6 year period seen in a trauma centre in Hong Kong. FAST findings were compared with laparotomy, abdominal computed tomography or autopsy findings, which served as the gold standard for presence of intraperitoneal free fluids. The patients who did not have FAST or gold standard confirmatory test performed, had preexisting peritoneal fluid, died at resuscitation or had imcomplete documentation of FAST findings were excluded. The performance of FAST was expressed as sensitivity, specificity, predictive values (PV), likelihood ratios (LR) and accuracy. RESULTS FAST was performed in 302 patients and 153 of them were included in this analysis. The sensitivity, specificity, positive PV, negative PV, positive LR, negative LR and accuracy for FAST were respectively 50.0%, 97.3%, 87.0%, 84.6%, 18.8, 0.5 and 85.0%. FAST was found to be more sensitive in less severely injured patients and more specific in more severely injured patients. CONCLUSION FAST is a reliable investigation in the initial assessment of BAT patients. The diagnostic values of FAST could be affected by the severity of injury and staff training is needed to further enhance its effective use. Key words: Laparotomy; Autopsy; Tomography, X-ray computed; Tomography, spiral computed; Ultrasonography.
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Affiliation(s)
- Kent Shek Cheung
- Department of Accident and Emergency, Queen Mary Hospital, 102 Pokfulam Road, Pokfulam, Hong Kong, China
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10
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Luo P, Reed BD, Tsang TC, Harris DT, Flavell RA. A self-augmenting gene expression cassette for enhanced and sustained transgene expression in the presence of proinflammatory cytokines. DNA Cell Biol 2007; 25:659-67. [PMID: 17184167 DOI: 10.1089/dna.2006.25.659] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Viral promoters can yield high gene expression levels yet tend to be attenuated in vivo by host proinflammatory cytokines. Prolonged transgene expression can be obtained using constitutive cellular promoters. However, levels of transgene expression driven by cellular promoters are insufficient for effective therapy. We designed a novel self-augmenting gene expression cassette in which the transgene product can induce an endogenous transcription factor to enhance the activity of a weak cellular promoter driving its expression. Using the cellular major histocompatibility complex class I (H-2K(b)) promoter to drive the interferon (IFN-gamma) cytokine gene, we show that the H-2K(b) promoter, although exhibiting much lower basal activity, yields higher IFN-gamma production than the CMV promoter 2 days after transfection. IFN-gamma expression driven by the H-2K(b) promoter also lasts longer than that driven by the cytomegalovirus promoter. Our data demonstrate that the self-augmenting strategy provides a promising approach to achieve high and sustained transgene expression in vivo.
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Affiliation(s)
- P Luo
- Department of Immunology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
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11
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Luo P, Tsang TC, He X, Gonzalez-Pena V, Jaramillo M, Takeuchi C, Harris DT. Novel amplifier expression vectors producing higher levels of IL-2 led to slower tumor growth and longer survival in vivo. DNA Cell Biol 2006; 24:595-604. [PMID: 16153160 DOI: 10.1089/dna.2005.24.595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Sufficient levels of gene expression are required for effective gene therapy. One of the major obstacles in gene therapy is the low transgene expression obtained from currently available vector systems. To address this issue, we employed a transcriptional amplifier strategy in a single construct to enhance transgene expression. In the amplifier vectors (pHi-1 and pHi-2), the strong CMV promoter was used to drive a transcriptional factor, Tat, which could transactivate a second promoter (HIV1 LTR or HIV2 LTR) located in the same construct driving the gene of interest. Using the human interleukin-2 (IL-2) cytokine gene, our data showed that the pHi-1/2 amplifier vectors could produce significantly higher IL-2 levels in human lung cancer cells (A549) and breast cancer cells (MCF-7) than that obtained by directly using the CMV promoter alone. Injection of pHi-2-IL-2-modified Lewis Lung (LL/2) tumor clones led to significantly slower tumor growth and longer survival in mice compared to those injected with either CMV promoter driven IL-2 clones or the parental tumor cells. Our results demonstrated that the transcriptional amplifier-based expression cassettes could be very useful in applications where high levels of gene expression are difficult to achieve.
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Affiliation(s)
- P Luo
- Gene Therapy Group, Department of Microbiology and Immunology, University of Arizona, Tucson, 85724, USA.
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12
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Luo P, Tsang TC, Takeuchi C, Dekker J, Badowski M, Harris DT. High-efficiency cloning system for versatile adaptation of DNA fragments. Biotechniques 2002; 33:738, 740, 742. [PMID: 12398178 DOI: 10.2144/02334bm04] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- P Luo
- Dept of Microbiology and Immunology, University of Arizona, Tucson 85721, USA.
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Abstract
The objectives of this study were to quantity and compare the activities of a minimal heat shock (HS) promoter and other promoters used in gene therapy applications, and to identify strategies to amplify the heat inducibility of therapeutic genes. Human tumour cells were transiently or stably transfected with the HS promoter driving expression of reporter genes. HS promoter activity was induced transiently, with maximum activity 16-24 h after HS, and was dependent on temperature. The activity of the minimal HS promoter was similar, after 42 degrees C HS for 1 h, to that of the cytomegalovirus (CMV) promoter. To determine if the HS promoter could be used to activate a second conditional promoter, cells were transiently transfected with vectors containing both the HS and human immunodeficiency virus type 1 (HIV1) promoters. When the IL-2 gene was placed downstream of the HIV1 promoter. IL-2 production was temperature-independent. The addition of the HIV tat gene downstream of the HS promoter caused IL-2 to be induced more than 3 fold after a single 42 degrees C HS. These data indicate that the minimal HS promoter, following activation by clinically attainable temperatures (< or = 42 degrees C), can drive expression of therapeutic genes at levels comparable to the CMV promoter and be used in conjunction with a second conditional promoter to drive temperature-dependent, gene expression.
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Affiliation(s)
- E W Gerner
- Department of Radiation Oncology, Cancer Biology Section, Arizona Cancer Center, The University of Arizona, Tucson 85724, USA.
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14
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Tsang TC, Brailey JL, Vasanwala FH, Wu RS, Liu F, Clark PR, Meade-Tollin L, Luznick L, Stopeck AT, Akporiaye ET, Harris DT. Construction of new amplifier expression vectors for high levels of IL-2 gene expression. Int J Mol Med 2000; 5:295-300. [PMID: 10677573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
The success of IL-2 gene therapy in cancer is in part dependent on the development of high level IL-2 gene expression vectors. Currently, expression vectors based on the human cytomegalovirus (CMV) promoter give the highest levels of expression. We have attempted to construct new IL-2 expression vectors to test whether gene expression can be further increased. The first approach was to use the new SR-alpha promoter to control IL-2 gene expression. The second approach was to combine the Tat transcription activator gene and the HIV 1 and 2 promoters in the same construct so that the levels of gene expression can be amplified. Transient transfection results using the human colon cancer cell line SW480 showed that the SR-alpha promoter yields similar levels of activity as the CMV promoter. However, the HIV 1 and 2 promoter-based amplifier constructs produced 11 and 28 times more secreted IL-2 than the CMV promoter control. The augmented activity of the amplifier constructs was dependent on the presence of the Tat gene and the transcriptional units must be placed in the same orientation. Reducing the size of the vectors by elimination of the neomycin selectable marker did not increase the activity of the constructs.
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Affiliation(s)
- T C Tsang
- Department of Microbiology, University of Arizona College of Medicine, Arizona Cancer Center, Tucson, AZ 85724, USA
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15
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Tsang TC, Brailey JL, Vasanwala FH, Wu RS, Liu F, Clark PR, Meade-Tollin L, Luznick L, Stopeck AT, Akporiaye ET, Harris DT. Construction of new amplifier expression vectors for high levels of IL-2 gene expression. Int J Mol Med 2000. [DOI: 10.3892/ijmm.5.3.295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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16
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Meade-Tollin LC, Boukamp P, Fusenig NE, Bowen CP, Tsang TC, Bowden GT. Differential expression of matrix metalloproteinases in activated c-ras-Ha-transfected immortalized human keratinocytes. Br J Cancer 1998; 77:724-30. [PMID: 9514050 PMCID: PMC2149968 DOI: 10.1038/bjc.1998.119] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Elevated expression of matrix metalloproteinases (MMPs), a family of secreted proteinases that degrade matrix components of basement membranes and connective tissues, is strongly correlated with malignant expression in various human epithelial cancers and epithelial cancer cell lines. We have tested whether elevated levels of MMP expression are also associated with malignant progression in human cutaneous squamous cell carcinoma. Constitutive levels of expression of steady-state mRNA and of secreted protein encoded by three MMP genes (matrilysin, gelatinases A and B) were compared in a unique in vitro model of human skin carcinogenesis. This model is composed of the parental immortalized non-tumorigenic human keratinocyte line (HaCaT), and three activated c-Harvey-ras-oncogene transfected variants (A-4, I-7 and II-4). Although clone A-4 is non-tumorigenic, clones I-7 and II-4 exhibit benign and malignant tumorigenic phenotypes, respectively, after subcutaneous injection into athymic nude mice. Northern blot, Western blot, and zymogram analyses revealed three MMP-specific patterns of expression. Constitutive matrilysin mRNA expression was markedly increased in the I-7 cells compared with HaCaT, A-4 or II-4 cells. Secreted promatrilysin was distinctly increased in the tumorigenic I-7 and II-4 cells compared with the non-tumorigenic HaCaT and A-4 cells. Gelatinase A mRNA and secreted gelatinase A protein levels were increased in each transfectant compared with HaCaT. Both active and inactive forms of gelatinase A were detected. Gelatinase B transcripts were not detected, but an EDTA-inhibitable gelatinase activity comigrating with gelatinase B was moderately enhanced in both tumorigenic variants compared with the non-tumorigenic cells. Because promatrilysin and 92-kDa gelatinase secretion were increased in both benign and malignant tumorigenic cells, and not related to invasiveness in this model, it is concluded that enhanced constitutive expression of these two MMPs is associated with acquisition of the tumorigenic phenotype, before acquisition of the malignant phenotype.
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Affiliation(s)
- L C Meade-Tollin
- University of Arizona, Arizona Cancer Center, Department of Radiation Oncology, Tucson 85724, USA
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17
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Tsang TC, Harris DT, Akporiaye ET, Chu RS, Brailey J, Liu F, Vasanwala FH, Schluter SF, Hersh EM. Mammalian expression vector with two multiple cloning sites for expression of two foreign genes. Biotechniques 1997; 22:68. [PMID: 8994649 DOI: 10.2144/97221bm13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Affiliation(s)
- T C Tsang
- Department of Microbiology and Immunology, University of Arizona, Tucson 85721, USA
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18
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Tsang TC, Harris DT, Akporiaye ET, Schluter SF, Bowden GT, Hersh EM. Simple method for adapting DNA fragments and PCR products to all of the commonly used restriction sites. Biotechniques 1996; 20:51-2. [PMID: 8770406 DOI: 10.2144/96201bm11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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19
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Schmidt AM, Mora R, Cao R, Yan SD, Brett J, Ramakrishnan R, Tsang TC, Simionescu M, Stern D. The endothelial cell binding site for advanced glycation end products consists of a complex: an integral membrane protein and a lactoferrin-like polypeptide. J Biol Chem 1994; 269:9882-8. [PMID: 8144581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Advanced glycation end products (AGEs), formed as the result of the extended interaction of proteins with ketoses, modulate central properties of endothelial cells and mononuclear phagocytes by interacting with a cell surface binding site comprised of a novel integral membrane protein (receptor for AGE = RAGE) and a lactoferrin-like polypeptide (LF-L), the latter having sequence identity to lactoferrin (LF). To further understand this cellular binding site, the interaction of RAGE with LF-L and LF was characterized. By ligand blotting and a solid state competitive binding assay, 125I-LF-L and 125I-LF bound to RAGE immobilized on nitrocellulose membranes or polypropylene tubes in a time-dependent and reversible manner, demonstrating a high affinity component with Kd approximately 100 pM. The interaction of 125I-LF-L and 125I-LF with RAGE was independent of iron in LF and was competed by addition of an excess of unlabeled carboxyl-terminal portion of LF. Cross-linking studies with purified 125I-LF-L and RAGE, in the presence of disuccinimidyl suberate, showed a new, slowly migrating band, corresponding to a complex of RAGE and LF-L, and cross-linking on mouse aortic endothelial cells showed two new slowly migrating bands on immunoblotting visualized with both anti-RAGE IgG and anti-LF-L IgG. These data lead us to propose that the endothelial cell surface binding site for AGEs consists of LF-L bound noncovalently to RAGE anchored in the cell membrane.
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Affiliation(s)
- A M Schmidt
- Department of Physiology, Columbia University, College of Physicians and Surgeons, New York, New York 10032
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20
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Tsang TC, Chu YW, Powell MB, Kittelson J, Meade-Tollin L, Hendrix MJ, Bowden GT. v-jun oncogene suppresses both phorbol ester-induced cell invasion and stromelysin gene expression in a mouse papilloma cell line. Cancer Res 1994; 54:882-6. [PMID: 8313375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The viral jun (v-jun) oncogene encodes a transcription factor that can participate in the transactivation of genes through the AP-1 complex. Evidence indicates that the ability of v-jun to transform cells and stimulate transcription depends on the cell type. We have asked whether expression of the v-jun gene in benign tumor forming mouse keratinocytes that already express an activated c-rasHa oncogene would cause malignant progression. Our results showed that the v-jun transfection did not result in malignant progression; instead, we made the unexpected observation that the ability of these cells to invade reconstituted basement membrane matrix (in vitro) in response to the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate, was suppressed. This phenomenon could, in part, be explained by the suppression of the induction by phorbol ester of expression of the metalloproteinase, stromelysin (transin). Of interest was the finding that 12-O-tetradecanoylphorbol-13-acetate induction of other cellular genes known to be regulated by AP-1 was not inhibited in the benign tumor cells expressing v-jun.
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Affiliation(s)
- T C Tsang
- Department of Radiation Oncology, College of Medicine, University of Arizona, Tucson 85724
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21
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Abstract
The 70 kDa family of heat-shock proteins (hsp 70s and hsc 70s) can facilitate protein transport to several organelles. This process is thought to involve electrostatic interactions between hsp 70s and the cellular protein targeting sequences. Analysis of the highly conserved structural and functional properties of the hsp 70 family indicated that they may cross-link cellular proteins to the actin microfilament network. Direct experimental support for this hypothesis was provided by the finding that hsp 70 is constitutively bound to actin through hydrophobic interactions. The cross-linker model may provide an explanation for the mechanism by which the cytoskeletal matrix could mediate various cellular processes.
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Affiliation(s)
- T C Tsang
- Department of Microbiology and Immunology, College of Medicine, University of Arizona, Tucson 85724
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22
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Larigan JD, Tsang TC, Rumberger JM, Burns DK. Characterization of cDNA and genomic sequences encoding rabbit ELAM-1: conservation of structure and functional interactions with leukocytes. DNA Cell Biol 1992; 11:149-62. [PMID: 1372169 DOI: 10.1089/dna.1992.11.149] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Endothelial leukocyte adhesion molecule-1 (ELAM-1) is a cytokine-inducible endothelial cell surface glycoprotein involved in the adherence of neutrophils. ELAM-1 belongs to the selectin family of cell-surface molecules characterized by the general structure of an amino-terminal lectin domain followed by an epidermal growth factor domain, a variable number of complement regulatory elements, a single transmembrane sequence, and a short cytoplasmic tail. To study the in vivo regulation and expression of ELAM-1, we have isolated a complementary DNA (cDNA) clone encoding the rabbit homolog of human ELAM-1. The nucleotide sequence of the rabbit cDNA as well as its deduced amino acid sequence display extensive conservation compared to the human sequences. Rabbit ELAM-1 contains the characteristic protein domain organization of the selectin gene family and shares 74% amino acid identity with its human counterpart. However, rabbit ELAM-1 contains five complement regulatory elements whereas the human protein has six of these elements. Characterization of the genomic sequence encoding rabbit ELAM-1 indicated that individual extracellular protein domains are encoded by distinct exons. The genomic organization of rabbit ELAM-1 parallels that found for the human ELAM-1 gene and is similar to the pattern observed for other selectin family members (GMP-140, Lam-1), consistent with the hypothesis that the selectins evolved by duplication and rearrangement of individual exons. COS cells transiently expressing the rabbit ELAM-1 cDNA mediate the adhesion of rabbit and human polymorphonuclear leukocytes and are recognized by antibodies prepared against the human protein. Our results suggest that the specificity of molecular interaction between ELAM-1 and its ligand is highly conserved.
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Affiliation(s)
- J D Larigan
- Department of Molecular Genetics, Hoffmann-La Roche Inc., Roche Research Center, Nutley, NJ 07110
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23
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Metz CN, Zhang YY, Guo Y, Tsang TC, Kochan JP, Altszuler N, Davitz MA. Production of the glycosylphosphatidylinositol-specific phospholipase D by the islets of Langerhans. J Biol Chem 1991; 266:17733-6. [PMID: 1833386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A large number of diverse cell surface proteins are anchored to the cell membrane by a glycosylphosphatidylinositol (GPI) anchor. One proposed function for the GPI anchor is that it facilitates the release of the protein from the cell by acting as a target for anchor-specific phospholipases. We and others have discovered that mammalian plasma contains a GPI-specific phospholipase D (GPI-PLD) (Cardoso de Almeida, M. L., Turner, M. J., Stambuk, B. V., and Schenkman, S. (1988) Biochem, Biophys. Res. Commun. 150, 476-482; Davitz, M. A., Hereld, D., Shak, S., Krakow, J., Englund, P. T., and Nussenzweig, V. (1987) Science 238, 81-84; Low, M. G., and Prasad, A. R. S. (1988) Proc. Natl. Acad. Sci. U. S. A. 85, 980-984). Because the GPI-PLD recognizes a conserved portion of the anchor, all GPI-anchored proteins are potential substrates for the enzyme. We demonstrate in this communication the production of the plasma GPI-PLD by the islets of Langerhans. GPI-PLD enzymatic activity was found in dog pancreatic microsomes, but not pancreatic juice. Both the pancreatic and plasma enzymes were divalent cation-dependent and had identical substrate specificities. Purified murine islets of Langerhans, as well as alpha and beta cells, contained and released GPI-PLD activity. A GPI-PLD DNA fragment was amplified by polymerase chain reaction from a normal human islet cDNA library; the amplified fragment hybridized with the GPI-PLD cDNA clone. These findings represent the first demonstration of the production of the plasma GPI-PLD by a specific tissue site as well as cell type.
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Affiliation(s)
- C N Metz
- Department of Pathology, New York University School of Medicine, New York 10016
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24
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Scallon BJ, Fung WJ, Tsang TC, Li S, Kado-Fong H, Huang KS, Kochan JP. Primary structure and functional activity of a phosphatidylinositol-glycan-specific phospholipase D. Science 1991; 252:446-8. [PMID: 2017684 DOI: 10.1126/science.2017684] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A phosphatidylinositol-glycan-specific phospholipase D (PI-G PLD) that specifically hydrolyzes the inositol phosphate linkage in proteins anchored by phosphatidylinositol-glycans (PI-Gs) has recently been purified from human and bovine sera. The primary structure of bovine PI-G PLD has now been determined and the functional activity of the enzyme has been studied. Expression of PI-G PLD complementary DNA in COS cells produced a protein that specifically hydrolyzed the inositol phosphate linkage of the PI-G anchor. Cotransfection of PI-G PLD with a PI-G-anchored protein resulted in the secretion of the PI-G-anchored protein. The results suggest that the expression of PI-G PLD may influence the expression and location of PI-G-anchored proteins.
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Affiliation(s)
- B J Scallon
- Department of Molecular/Cellular Biology and Biochemistry, Hoffmann-La Roche, Inc., Nutley, NJ 07110
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25
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Tsang TC, Bentley DR, Nilsson IM, Giannelli F. The use of DNA amplification for genetic counselling related diagnosis in haemophilia B. Thromb Haemost 1989; 61:343-7. [PMID: 2572072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A single base pair variation in the coding sequence of coagulation factor IX produces a protein polymorphism detectable with monoclonal antibodies and a restriction fragment length polymorphism (RFLP). This allows carrier and prenatal diagnoses in 48% of Caucasian families segregating for haemophilia B. However, this RFLP cannot be detected by standard Southern blotting, while the antibody assay may give equivocal results in some females and can only allow prenatal diagnoses on second trimester fetal blood samples. We show that, using the polymerase chain reaction, the polymorphic DNA segment can be amplified and directly tested for the presence of the alternative sequences by a non-radioactive procedure that has the advantage of speed (1-2 days), partial automation and applicability to first trimester diagnoses. We also show that the method gives results on a single drop of dried blood.
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Affiliation(s)
- T C Tsang
- Paediatric Research Unit, United Medical School of Guy's Hospital, London, United Kingdom
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Abstract
A novel factor IX gene mutation (factor IX London 2) has been characterized. This causes severe crm+ haemophilia B as the patient's plasma shows normal factor IX antigen level and less than 1% clotting activity. Sequence analysis of the entire cloned coding and promoter regions revealed a single point mutation: a G----A transition at position 31,119. This region of the patient's DNA was amplified in vitro by the polymerase chain reaction and the nucleotide change was confirmed by direct sequencing of the amplified products. The mutation results in the substitution of the arginine at position 333 by glutamine. This arginine residue is absolutely conserved in the catalytic domain of normal human and bovine factor IX, X and prothrombin. The substitution by glutamine causes the loss of a positive charge from the surface of the factor IX London 2 protein. This mutation pinpoints a previously unknown, functionally critical feature of factor IX which may be involved in substrate or co-factor binding.
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Affiliation(s)
- T C Tsang
- Division of Medical and Molecular Genetics, UMDS, London, UK
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27
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Affiliation(s)
- T C Tsang
- Paediatric Research Unit, UMDS, Guy's Hospital, London, UK
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