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Tai FMT, Lo YC, Chan PL. Aryepiglottic Cyst Developed Hours After Tracheal Intubation Causing Acute Upper Airway Ball-Valve Obstruction: A Case Report. A A Pract 2024; 18:e01756. [PMID: 38498669 DOI: 10.1213/xaa.0000000000001756] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
This is the first case report describing an aryepiglottic cyst resulting in critical airway compromise after an uneventful tracheal intubation. We present the case of a 55-year-old woman who developed acute dyspnea and stridor several hours after the surgery. She was found to have significant upper airway obstruction owing to a large left aryepiglottic cyst with a ball-valve effect.
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Affiliation(s)
- Florence M T Tai
- From the Department of Anaesthesia, Yan Chai Hospital, HKSAR, China
| | - Yat-Ching Lo
- From the Department of Anaesthesia, Yan Chai Hospital, HKSAR, China
| | - Po-Ling Chan
- Department of Ear, Nose and Throat, Prince of Wales Hospital, HKSAR, China
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2
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Hou J, Lam KL, Chiu YT, Kwong KY, Lau HL, Marafa LM, Tsui SKW, Mo IWY, Chan PL. Urban green waste bulking agent is the major source of antimicrobial resistance genes persisted in home compost, not animal manure. Environ Res 2024; 242:117713. [PMID: 38000633 DOI: 10.1016/j.envres.2023.117713] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/27/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023]
Abstract
Urban green waste and food waste are often used as bulking agents to prepare home compost in combination with animal manure in urban horticulture and community gardening. Although it is known that antimicrobial resistance genes (ARGs) persist in home compost, their origins have not been determined. In addition, the factors contributing to ARGs persistence remain unclear. In this study, we aim to (i) characterize the changes in the microbiome and antimicrobial resistome during the composting process of home compost using metagenomics shotgun sequencing, (ii) identify the source of the ARGs persisted in home compost using SourceTracker, and (iii) elucidate the collective effect of compost microbiome and environmental factors, including the physicochemical properties and antibiotics concentration of home compost, in contributing to ARG persistence using Procrustes analysis, co-occurrence network analysis, variation partitioning analysis, and structural equation modeling. SourceTracker analysis indicated that urban green waste bulking agent was the major source of the persisting ARGs in home compost instead of animal manure. Procrustes analysis and co-occurrence network analysis revealed a strong association between microbiome and antimicrobial resistome. Variation partitioning analysis and structural equation modeling suggested that physicochemical properties shaped the antimicrobial resistome directly and indirectly by influencing the microbiome. Our results indicated that the persistence of ARGs in home compost might be due to the succession of microbial species from the urban green waste bulking agent, and the physicochemical properties might have defined the compost environment to shape the microbiome in the compost, thus, in turn, the persisting antimicrobial resistome.
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Affiliation(s)
- Jinpao Hou
- School of Biomedical Sciences, the Chinese University of Hong Kong, Shatin, Hong Kong
| | - K L Lam
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong
| | - Y T Chiu
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong
| | - K Y Kwong
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong
| | - H L Lau
- Department of Geography and Resources Management, the Chinese University of Hong Kong, Shatin, Hong Kong
| | - L M Marafa
- Department of Geography and Resources Management, the Chinese University of Hong Kong, Shatin, Hong Kong
| | - S K W Tsui
- School of Biomedical Sciences, the Chinese University of Hong Kong, Shatin, Hong Kong
| | - I W Y Mo
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong.
| | - P L Chan
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong; Department of Health Sciences, School of Nursing and Health Studies, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong.
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3
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Law MKK, Ma LWY, Lai AYT, Chan PL, Au AKY, Ling YH, Wong WWC. Magseed Localisation of Non-palpable Papillary Lesions: a Pictorial Essay. Hong Kong Journal of Radiology 2022. [DOI: 10.12809/hkjr2217389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- MKK Law
- Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - LWY Ma
- Department of Surgery, Ruttonjee Hospital, Hong Kong
| | - AYT Lai
- Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - PL Chan
- Department of Surgery, Ruttonjee Hospital, Hong Kong
| | - AKY Au
- Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Hong Kong
| | - YH Ling
- Department of Surgery, Ruttonjee Hospital, Hong Kong
| | - WWC Wong
- Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Hong Kong
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Fang G, Chow MCK, Ho JDL, He Z, Wang K, Ng TC, Tsoi JKH, Chan PL, Chang HC, Chan DTM, Liu YH, Holsinger FC, Chan JYK, Kwok KW. Soft robotic manipulator for intraoperative MRI-guided transoral laser microsurgery. Sci Robot 2021; 6:6/57/eabg5575. [PMID: 34408096 DOI: 10.1126/scirobotics.abg5575] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 07/27/2021] [Indexed: 01/14/2023]
Abstract
Magnetic resonance (MR) imaging (MRI) provides compelling features for the guidance of interventional procedures, including high-contrast soft tissue imaging, detailed visualization of physiological changes, and thermometry. Laser-based tumor ablation stands to benefit greatly from MRI guidance because 3D resection margins alongside thermal distributions can be evaluated in real time to protect critical structures while ensuring adequate resection margins. However, few studies have investigated the use of projection-based lasers like those for transoral laser microsurgery, potentially because dexterous laser steering is required at the ablation site, raising substantial challenges in the confined MRI bore and its strong magnetic field. Here, we propose an MR-safe soft robotic system for MRI-guided transoral laser microsurgery. Owing to its miniature size (Ø12 × 100 mm), inherent compliance, and five degrees of freedom, the soft robot ensures zero electromagnetic interference with MRI and enables safe and dexterous operation within the confined oral and pharyngeal cavities. The laser manipulator is rapidly fabricated with hybrid soft and hard structures and is powered by microvolume (<0.004 milliter) fluid flow to enable laser steering with enhanced stiffness and lowered hysteresis. A learning-based controller accommodates the inherent nonlinear robot actuation, which was validated with laser path-following tests. Submillimeter laser steering accuracy was demonstrated with a mean error < 0.20 mm. MRI compatibility testing demonstrated zero observable image artifacts during robot operation. Ex vivo tissue ablation and a cadaveric head-and-neck trial were carried out under MRI, where we employed MR thermometry to monitor the tissue ablation margin and thermal diffusion intraoperatively.
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Affiliation(s)
- Ge Fang
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China
| | - Marco C K Chow
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China
| | - Justin D L Ho
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China
| | - Zhuoliang He
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China
| | - Kui Wang
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China
| | - T C Ng
- Faculty of Dentistry, University of Hong Kong, Hong Kong, China
| | - James K H Tsoi
- Faculty of Dentistry, University of Hong Kong, Hong Kong, China
| | - Po-Ling Chan
- Department of Otorhinolaryngology, Head and Neck Surgery, Chinese University of Hong Kong, Hong Kong, China
| | - Hing-Chiu Chang
- Department of Diagnostic Radiology, University of Hong Kong, Hong Kong, China.,Department of Biomedical Engineering, Chinese University of Hong Kong, Hong Kong, China
| | | | - Yun-Hui Liu
- Department of Mechanical and Automation Engineering, Chinese University of Hong Kong, Hong Kong, China
| | | | - Jason Ying-Kuen Chan
- Department of Otorhinolaryngology, Head and Neck Surgery, Chinese University of Hong Kong, Hong Kong, China.
| | - Ka-Wai Kwok
- Department of Mechanical Engineering, University of Hong Kong, Hong Kong, China.
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5
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Tong HS, Ng YL, Liu Z, Ho JDL, Chan PL, Chan JYK, Kwok KW. Real-to-virtual domain transfer-based depth estimation for real-time 3D annotation in transnasal surgery: a study of annotation accuracy and stability. Int J Comput Assist Radiol Surg 2021; 16:731-739. [PMID: 33786777 PMCID: PMC8134290 DOI: 10.1007/s11548-021-02346-9] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/05/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE Surgical annotation promotes effective communication between medical personnel during surgical procedures. However, existing approaches to 2D annotations are mostly static with respect to a display. In this work, we propose a method to achieve 3D annotations that anchor rigidly and stably to target structures upon camera movement in a transnasal endoscopic surgery setting. METHODS This is accomplished through intra-operative endoscope tracking and monocular depth estimation. A virtual endoscopic environment is utilized to train a supervised depth estimation network. An adversarial network transfers the style from the real endoscopic view to a synthetic-like view for input into the depth estimation network, wherein framewise depth can be obtained in real time. RESULTS (1) Accuracy: Framewise depth was predicted from images captured from within a nasal airway phantom and compared with ground truth, achieving a SSIM value of 0.8310 ± 0.0655. (2) Stability: mean absolute error (MAE) between reference and predicted depth of a target point was 1.1330 ± 0.9957 mm. CONCLUSION Both the accuracy and stability evaluations demonstrated the feasibility and practicality of our proposed method for achieving 3D annotations.
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Affiliation(s)
- Hon-Sing Tong
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Yui-Lun Ng
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Zhiyu Liu
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Justin D L Ho
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Po-Ling Chan
- Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR
| | - Jason Y K Chan
- Department of Otorhinolaryngology, Head and Neck Surgery, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR.
| | - Ka-Wai Kwok
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong.
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Wong VKW, Li T, Law BYK, Ma EDL, Yip NC, Michelangeli F, Law CKM, Zhang MM, Lam KYC, Chan PL, Liu L. Saikosaponin-d, a novel SERCA inhibitor, induces autophagic cell death in apoptosis-defective cells. Cell Death Dis 2013; 4:e720. [PMID: 23846222 PMCID: PMC3730398 DOI: 10.1038/cddis.2013.217] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 11/08/2022]
Abstract
Autophagy is an important cellular process that controls cells in a normal homeostatic state by recycling nutrients to maintain cellular energy levels for cell survival via the turnover of proteins and damaged organelles. However, persistent activation of autophagy can lead to excessive depletion of cellular organelles and essential proteins, leading to caspase-independent autophagic cell death. As such, inducing cell death through this autophagic mechanism could be an alternative approach to the treatment of cancers. Recently, we have identified a novel autophagic inducer, saikosaponin-d (Ssd), from a medicinal plant that induces autophagy in various types of cancer cells through the formation of autophagosomes as measured by GFP-LC3 puncta formation. By computational virtual docking analysis, biochemical assays and advanced live-cell imaging techniques, Ssd was shown to increase cytosolic calcium level via direct inhibition of sarcoplasmic/endoplasmic reticulum Ca(2+) ATPase pump, leading to autophagy induction through the activation of the Ca(2+)/calmodulin-dependent kinase kinase-AMP-activated protein kinase-mammalian target of rapamycin pathway. In addition, Ssd treatment causes the disruption of calcium homeostasis, which induces endoplasmic reticulum stress as well as the unfolded protein responses pathway. Ssd also proved to be a potent cytotoxic agent in apoptosis-defective or apoptosis-resistant mouse embryonic fibroblast cells, which either lack caspases 3, 7 or 8 or had the Bax-Bak double knockout. These results provide a detailed understanding of the mechanism of action of Ssd, as a novel autophagic inducer, which has the potential of being developed into an anti-cancer agent for targeting apoptosis-resistant cancer cells.
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Affiliation(s)
- V KW Wong
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau, China
| | - T Li
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau, China
| | - B YK Law
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau, China
| | - E DL Ma
- Department of Chemistry, Hong Kong Baptist University, Hong Kong, China
| | - N C Yip
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - F Michelangeli
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - C KM Law
- Shum Yiu Foon Shum Bik Chuen Memorial Centre for Cancer and Inflammation Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - M M Zhang
- Shum Yiu Foon Shum Bik Chuen Memorial Centre for Cancer and Inflammation Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - K YC Lam
- Shum Yiu Foon Shum Bik Chuen Memorial Centre for Cancer and Inflammation Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - P L Chan
- Shum Yiu Foon Shum Bik Chuen Memorial Centre for Cancer and Inflammation Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong, China
| | - L Liu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau, China
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Abstract
This is the first detailed characterization of the airborne bacterial profiles in indoor environments. Two restaurants were selected for this study. Fifteen genera of bacteria were isolated from each restaurant and identified by three different bacterial identification systems including MIDI, Biolog and Riboprinter. The dominant bacteria of both restaurants were Gram-positive bacteria in which Micrococcus and Bacillus species were the most abundant. Most bacteria identified were representative species of skin and respiratory tract of human, and soil. Although the bacterial levels in these two restaurants were below the limit of the Hong Kong Indoor Air Quality Objective (HKIAQO) Level 1 standard (i.e., < 500 cfu/m3), the majority of these bacteria were opportunistic pathogens. These results suggested that the identity of airborne bacteria should also be included in the IAQ to ensure there is a safety guideline for the public.
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Affiliation(s)
- P L Chan
- Department of Biology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
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Ma TC, Chan PL, Lawford H, Chua H, Lo WH, Yu PH. Microbial synthesis and characterization of physiochemical properties of polyhydroxyalkanoates (PHAs) produced by bacteria isolated from activated sludge obtained from the municipal wastewater works in Hong Kong. Appl Biochem Biotechnol 2005; 121-124:731-9. [PMID: 15920276] [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: 05/02/2023]
Abstract
The first objective of this study was the measurement of physical properties of P(3HB-co-3HV) copolymers with different (hydroxybutyrate) HB to (hydroxyvalerate) HV ratios produced by Bacillus cereus (TRY2) isolated from activated sludge. The 3HV PHBV copolymers were 0.05, 22.6, 39.2, 54.1, and 69.1 mol%, respectively. The second objective was to study possible waste water treatment and production of PHAs at the same time by B. cereus (TRY2) and Pseudomonas spp. (TOB17) (both were isolated from activated sludge), recombinant Bacillus DH5alpha, and a combination of the above three bacteria. The results were satisfactory; the maximum COD and TOC of the sewage sludge reduced were 53.5% and 67.5%, respectively.
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Affiliation(s)
- Tsz-Chun Ma
- State Key Lab of Chinese Med and Molecular Pharmacology, Shenzen, China
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9
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King AD, Ching ASC, Chan PL, Cheng AYH, Wong PK, Ho SSY, Griffith JF, Lyon DJ, Fung KSC, Choi P, Li CK, Cheng AFB, Ahuja AT. Severe acute respiratory syndrome: avoiding the spread of infection in a radiology department. AJR Am J Roentgenol 2003; 181:25-7. [PMID: 12818824 DOI: 10.2214/ajr.181.1.1810025] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- A D King
- Department of Diagnostic Radiology and Organ Imaging, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong S.A.R. China
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10
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Ho SSY, Chan PL, Wong PK, Antonio GE, Wong KT, Lyon DJ, Fung KSC, Li CK, Cheng AFB, Ahuja AT. Eye of the storm: the roles of a radiology department in the outbreak of severe acute respiratory syndrome. AJR Am J Roentgenol 2003; 181:19-24. [PMID: 12818823 DOI: 10.2214/ajr.181.1.1810019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- S S Y Ho
- Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, 30-32 Ngan Shing St., Shatin, New Territories, Hong Kong, China
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11
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Leung TW, Leung WC, Chan PL, Ho PC. A comparison of the prevalence of domestic violence between patients seeking termination of pregnancy and other general gynecology patients. Int J Gynaecol Obstet 2002; 77:47-54. [PMID: 11929659 DOI: 10.1016/s0020-7292(01)00596-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [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: 10/18/2022]
Abstract
OBJECTIVES (1) To determine and compare the prevalence of domestic violence among abortion-seeking patients with other general gynecology patients; (2) to see if a follow-up interview 6 weeks after abortion can improve the abuse disclosure rate; (3) to see if the abused victims accept direct referral to their gynecologists/social workers for help. METHODS This is a prospective questionnaire survey in a university teaching hospital on patients seeking abortion and an approximately equal number of other general gynecology patients. Participants were interviewed by a designated project nurse in a private setting, using a structured questionnaire (Modified Abuse Assessment Screen Questionnaire) to assess the past and recent history of abuse. The interview was repeated 6 weeks after the abortion for the abortion-seeking group. RESULTS Five hundred and one participants were interviewed, including 245 seeking abortion (TOP group) and 256 other general gynecology patients (non-TOP group). The lifetime prevalence of abuse in the TOP group (27.3%) was significantly higher than the non-TOP group (8.2%) (P<0.001). Repeating the interview 6 weeks after the abortion did not increase the disclosure rate. Most abused victims were unwilling to disclose their information of abuse to their gynecologists or social workers at the time of interview. CONCLUSIONS Domestic violence is a significant problem among the gynecology patients, particularly those seeking abortion. A single interview prior to abortion is adequately effective for screening. However, the most effective and acceptable way of helping these victims needs to be explored further.
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Affiliation(s)
- T W Leung
- Department of Obstetrics & Gynecology, The University of Hong Kong, Queen Mary Hospital, Pokfulam Road, SAR, Hong Kong, PR China.
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12
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Abstract
Degenerative diseases are characterized by a worsening of disease status over time. The rate of deterioration is determined by the natural rate of progression of the disease and by the effect of drug treatments. A goal of drug treatment is to slow disease progression. Drug treatments can be categorized as symptomatic or protective. Symptomatic treatments do not affect the rate of disease progression whereas protective treatments have the ability to slow disease progression down. Many current methods for describing disease progression have two common drawbacks: a linear relationship between time and disease status is assumed, and within- and between-subject variability is ignored. Disease progress models combined with pharmacokinetic pharmacodynamic models and hierarchical random effects statistical models provide insights into understanding the time course and management of degenerative disease.
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Affiliation(s)
- P L Chan
- Division of Pharmacology and Clinical Pharmacology, School of Medicine, University of Auckland, Private Bag 92019, Auckland 1030, New Zealand.
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13
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Abstract
The combined use of a lightwand and the intubating laryngeal mask airway (ILMA) was compared with the use of the ILMA alone to determine whether the combination was a more efficient method of endotracheal intubation. One hundred healthy patients were randomly assigned to two groups. After induction of anaesthesia, Group A patients were intubated blindly through the ILMA while in Group B, intubation was guided by a lightwand. A sequence of standard manoeuvres was followed it attempts at intubation failed. The number of manoeuvres used, the time taken for successful intubation and complications associated with intubation were recorded. Intubations were successful in all patients, but the mean endotracheal intubation time was longer in Group A than in Group B (38.3 +/- 10.4 s versus 26.4 +/- 9.1 s, P < 0.001). The number of patients who needed one or more manoeuvres was significantly higher in Group A than in Group B (76% versus 42%, P = 0.001). We conclude that the lightwand is a useful adjunct in endotracheal intubation through an ILMA.
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Affiliation(s)
- P L Chan
- Department of Anaesthesia and Intensive Care, Tuen Mun Hospital, Tuen Mun, New Territories, Hong Kong, PRC
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14
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Abstract
AIM To determine whether non-anaemic women with gestational diabetes mellitus (GDM) diagnosed in third trimester pregnancy have evidence of increased iron stores compared with matched non-diabetic controls. METHODS In a prospective study, women who had antenatal booking before 20 weeks' gestation and without anaemia or diabetes mellitus were recruited at the time of the oral glucose tolerance test (OGTT) at 28-31 weeks' gestation for the study of serum ferritin, iron and transferrin concentrations. The results were blinded to the managing obstetricians. After delivery, the records were reviewed. The cases diagnosed as GDM were compared with a control group (two controls for each index case matched for parity) selected at random from the at-risk but nondiabetic cases. RESULTS GDM was diagnosed in 97 of the 401 women recruited. Compared with the 194 controls, there was no difference in the weight, body mass index, booking and third trimester haemoglobin, or third trimester red cell indices, but concentrations of serum ferritin, iron, transferrin saturation, and the post-natal haemoglobin were significantly higher. On multiple regression analysis, maternal BMI and the log-transformed ferritin concentration remained significant determinants of the OGTT 2-h glucose value. CONCLUSION The results suggest an association between increased iron stores and glucose intolerance at the third trimester in non-anaemic women. The role of iron excess in the pathogenesis of GDM needs to be examined.
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Affiliation(s)
- T T Lao
- Department of Obstetrics and Gynaecology, The University of Hong Kong, Tsan Yuk Hospital, Hong Kong, PRC
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15
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Abstract
AIMS Paracetamol has a central action for both antipyresis and analgesia. Maximum temperature decrease and peak analgesia are reported at 1-2 h after peak plasma paracetamol concentration. We wished to determine the relationship between plasma and cerebrospinal fluid (CSF) pharmacokinetics in children. METHODS Concentration-time profiles in plasma and CSF after nasogastric paracetamol 40 mg kg(-1) were measured in nine children who had indwelling ventricular drains. Estimation of population pharmacokinetic parameters was made using both a standard two-stage population approach (MKMODEL) and a nonlinear mixed effect model (NONMEM). Results were standardized to a 70 kg person using an allometric power model. RESULTS Both approaches gave similar estimates. NONMEM parameter estimates were clearance 10.21 h(-1) (CV 47%), volume of distribution 67.11 (CV 58%) and absorption rate constant 0.77 h(-1) (CV 49%). Cerebrospinal fluid concentrations lagged behind those of plasma. The equilibration half time was 0.72 h (CV 117%). The CSF/plasma partition coefficient was 1.18 (CV 8%). CONCLUSIONS Higher concentrations in the CSF probably reflect the lower free water volume of plasma. The CSF equilibration half time suggests that CSF kinetics approximate more closely to the effect compartment than plasma, but further time is required for paracetamol to exert its effects. Effect site concentrations equilibrate slowly with plasma. Paracetamol should be given 1-2 h before anticipated pain or fever in children.
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Affiliation(s)
- B J Anderson
- Paediatric Intensive Care Department, Auckland Children's Hospital, New Zealand
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16
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Blais BW, Chan PL, Phillippe LM, Brooks BW, Hayashi S, Yamazaki H. Assay of Salmonella in enrichment cultures of foods, feeds and environmental samples by the polymyxin-cloth enzyme immunoassay. Int J Food Microbiol 1997; 37:183-8. [PMID: 9310853 DOI: 10.1016/s0168-1605(97)00072-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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: 02/05/2023]
Abstract
A variety of foods, animal feeds and environmental samples were analyzed for the presence of Salmonella using the polymyxin-cloth enzyme immunoassay (p-CEIA) system. Salmonella lipopolysaccharide (LPS) antigens were captured from test samples on polymyxin-coated polyester cloth, followed by immunoenzymatic detection of bound antigens using a monoclonal antibody recognizing an LPS common core oligosaccharide. Dairy and egg products, animal feeds and environmental samples from food processing plants were pre-enriched for 24 h, followed by selective enrichment for a further 24 h in either tetrathionate brilliant green (TBG), selenite cystine (SC) or brain-heart infusion broth containing 0.5% yeast extract, 0.5% cholate and 0.3% selenite (BYCS). The samples were assayed by the p-CEIA after each stage of enrichment. After selective enrichment, the p-CEIA gave results which were in complete agreement with the standard culture technique in the analysis of all foods examined. On the other hand, a combination of selective enrichment and the p-CEIA out-performed the Modified Semi-Solid Rappaport Vassiliadis (MSRV) method in screening pre-enrichment cultures of feeds and environmental samples. Use of the new selective medium BYCS prior to performing the p-CEIA gave the highest recovery of Salmonella from feeds and environmental samples.
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Affiliation(s)
- B W Blais
- Laboratory Services Division, Canadian Food Inspection Agency, Ottawa, Ontario, Canada
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17
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Arenson AM, Chan PL, Withers C, Leonhardt C, Kan J, Luong A. Value of standardized gestational age charts for fetuses of first-generation Oriental immigrants to Canada. Can Assoc Radiol J 1995; 46:111-3. [PMID: 7704672] [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: 01/26/2023] Open
Abstract
OBJECTIVE to ascertain if standard gestational age charts can be used to accurately predict the gestational age of fetuses of first-generation Oriental immigrants to Canada. PATIENTS AND METHODS Over a 3-year period, all patients presenting for obstetric ultrasound examinations were invited to participate in the study. The authors recorded biparietal diameter, head circumference, femur length and abdominal circumference for 139 fetuses in the second and third trimesters. A study performed in the first trimester was used as the baseline for gestational age. The data for 126 of the fetuses were complete, and these data were used for the analysis. RESULTS For 77 of the fetuses, both parents were Oriental, and for 49, one or both parents were not Oriental; the latter constituted the control group. A total of 1008 individual measurements were obtained, and of these, all but 14 fell within two standard deviations of the norm, according to standard gestational age charts. Of the abnormal measurements, seven were obtained from five fetuses with Oriental parents, and seven were obtained from six fetuses in the control group. The difference between the two groups in the proportion of measurements falling either above or below two standard deviations from the norm was not statistically significant (Fisher's exact test, p = 0.41694). CONCLUSION The authors conclude that standard gestational age charts can be used to determine gestational age in first-generation Oriental immigrants to Canada.
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Affiliation(s)
- A M Arenson
- Department of Radiological Sciences, Sunnybrook Health Science Centre, North York, ON
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Ploemacher RE, van der Sluijs JP, van Beurden CA, Baert MR, Chan PL. Use of limiting-dilution type long-term marrow cultures in frequency analysis of marrow-repopulating and spleen colony-forming hematopoietic stem cells in the mouse. Blood 1991; 78:2527-33. [PMID: 1824250] [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: 12/28/2022] Open
Abstract
We have developed an in vitro clonal assay of murine hematopoietic precursor cells that form spleen colonies (CFU-S day 12) or produce in vitro clonable progenitors in the marrow (MRA cells) of lethally irradiated mice. The assay is essentially a long-term bone marrow culture in microtiter wells containing marrow-derived stromal "feeders" depleted for hematopoietic activity by irradiation. To test the validity of the assay as a quantitative in vitro stem cell assay, a series of unsorted and physically sorted bone marrow cells were simultaneously assayed in vivo and overlaid on the feeders in a range of concentrations, while frequencies of cells forming hematopoietic clones (cobblestone area forming cells, CAFC) were calculated by means of Poisson statistics. Linear regression analysis of the data showed high correlations between the frequency of CFU-S day 12 and CAFC day 10, and between MRA cells and CAFC day 28. A majority of MRA activity and CAFC day 28 was separable from CFU-S day 12 and CAFC day 10. This correlation study validates the CAFC system as a clonal assay facilitation both the quantitative assessment of a series of subsets in the hematopoietic stem cell hierarchy and the study of single long-term repopulating cells in vitro.
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Affiliation(s)
- R E Ploemacher
- Department of Cell Biology II, Erasmus University, Rotterdam, The Netherlands
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Chan PL, Neale R. Spontaneous rupture of the vaginal vault with small bowel prolapse. Obstet Gynecol 1982; 60:754-6. [PMID: 7145283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Zoglio MA, Huber HE, Koehne G, Chan PL, Carstensen JT. Physical aspects of wet granulations II: factors involved in prolonged and excessive mixing. J Pharm Sci 1976; 65:1205-8. [PMID: 978438 DOI: 10.1002/jps.2600650818] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Evidence is presented that excessive blending in a wet granulation process shifts the packing arrangement of the wet granule, causing it to become dense and nonporous. With prolonged kneading, a large amount of the water-soluble excipients dissolves in the granulating fluid, and these two factors make the drying slower. This result, coupled with the previous finding that a certain time is required to attain an equilibrium size granule, explains why there exists an optimum kneading time for a wet granulation from a mechanical performance point of view.
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Sinclair NR, Lees RK, Chan PL. Interference with antibody-feedback by irradiation, thymus cells, the allogeneic effect, and serum factors. Adv Exp Med Biol 1976; 66:623-33. [PMID: 1083659 DOI: 10.1007/978-1-4613-4355-4_96] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Low doses of irradiation, increased number of T cells, increased T cell activity as in the allogeneic effect, or early activation of an in vitro cell-mediated immune response all confer resistance to antibody feedback. In some of these systems, the resistance is directed against immunosuppression by intact IgG antibody whereas suppression by F(ab')2 antibody is either not changed or increased. These forms of interference with immunosuppression by antibody, are explained in terms of an Fc-dependent model for antibody-feedback regulation.
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Yeung DL, Chan PL. Effects of a progestogen and a sequential type oral contraceptive on plasma vitamin A, vitamin E, cholesterol and triglycerides. Am J Clin Nutr 1975; 28:686-91. [PMID: 1146718 DOI: 10.1093/ajcn/28.7.686] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Fasting blood samples were taken from 13 college students who had never been on oral contraceptives in two menstrual cycles. During the first cycle, the control cycle, each girl donated three blood samples; the first sample was given between days 1 and 5, the second sample between days 13 and 17, and the third sample between days 22 and 26 of the menstrual cycle. In the second menstrual cycle, the experimental cycle, nine girls were given Micronor, a progestogen type oral contraceptive and four girls were given Ortho-Novum SQ, a sequential type oral contraceptive. Four blood samples were obtained from each of the subjects: the first three samples were obtained in the three periods corresponding to those in the control cycle, and the fourth was taken 2 days after the subjects had stopped taking the oral contraceptive. Results showed that estrogen significantly raised plasma vitamin A and triglycerides. The progestogen, at low concentration, had little or no effect on these two lipid materials. At a higher concentration the progestogen enhanced the effect of the estrogen on plasma vitamin A and triglycerides. These effects were extended to at least 2 days after subjects had ceased taking the oral contraceptive. Plasma vitamin E levels in the subjects given Ortho-Novum SQ, were consistently but not statistically higher in the experimental cycle than in the control cycle. The correlation coefficient between vitamin E and triglycerides was statistically significant while those between the vitamin A and vitamin E and between vitamin A and triglycerides were not. Cholesterol was not affected by either Micronor or Ortho-Novum SQ.
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Sinclair NR, Lees RK, Abrahams S, Chan PL, Fagan G, Stiller CR. Regulation of the immune response. X. Antigen-antibody complex inactivation of cells involved in adoptive transfer. J Immunol 1974; 113:1493-500. [PMID: 4608468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Chan PL, Sinclair NR. Regulation of the immune response. VI. Inability of F(ab') 2 antibody to terminate established immune responses and its ability to interfere with IgG antibody-mediated immunosuppression. Immunology 1973; 24:289-301. [PMID: 4576780 PMCID: PMC1423010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Intact IgG antibody can terminate established immune responses, whereas F(ab′)2 antibody cannot do so. The difference between the two antibodies appears to be qualitative. F(ab′)2 antibody, but not pepsin-digested normal serum, can interfere with the suppression and termination of immune responses induced by intact IgG antibody. These results are discussed in terms of the tripartite inactivation model.
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Chan PL, Sinclair NR. Immunologic and virologic properties of chemically and gamma-irradiation-induced thymic lymphomas in mice. J Natl Cancer Inst 1972; 48:1629-40. [PMID: 5066471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Sinclair NR, Lees RK, Chan PL, Khan RH. Regulation of the immune response. II. Further studies on differences in ability of F(ab')2 and 7S antibodies to inhibit an antibody response. Immunology 1970; 19:105-16. [PMID: 4922025 PMCID: PMC1455608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The ability of F(ab′)2 antibody preparations to suppress an immune response is much less than that of intact 7S antibody. The activity possessed by F(ab′)2 preparations withstood repurification procedures, hence contamination with intact 7S antibody is unlikely. Daily or thrice daily injections of antibody did not make equal the suppressive activities of F(ab′)2 and intact antibody, indicating that rapid excretion of F(ab′)2 antibody is not the sole factor involved in the difference in immunosuppressive potency between intact 7S and F(ab′)2 antibody. Some possibilities for distinct differences in the mechanism of the immuno-suppressive action of F(ab′)2 and 7S antibodies are raised and discussed.
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Chun D, Hip JK, Ma HK, Chan PL. Laparoscopic tubal sterilization. IPPF Med Bull 1970; 4:1-3. [PMID: 12275105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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