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Chen WJ, Ko IS, Lin CA, Chen CJ, Wu JS, Chan CK. Detection of Anticipatory Dynamics between a Pair of Zebrafish. Entropy (Basel) 2023; 26:13. [PMID: 38275492 DOI: 10.3390/e26010013] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024]
Abstract
Anticipatory dynamics (AD) is unusual in that responses from an information receiver can appear ahead of triggers from the source, and direction of information flow (DIF) is needed to establish causality. Although it is believed that anticipatory dynamics is important for animals' survival, natural examples are rare. Time series (trajectories) from a pair of interacting zebrafish are used to look for the existence of AD in natural systems. In order to obtain the DIF between the two trajectories, we have made use of a special experimental design to designate information source. However, we have also used common statistical tools such as Granger causality and transfer entropy to detect DIF. In our experiments, we found that a majority of the fish pairs do not show any anticipatory behaviors and only a few pairs displayed possible AD. Interestingly, for fish in this latter group, they do not display AD all the time. Our findings suggest that the formation of schooling of fish might not need the help of AD, and new tools are needed in the detection of causality in AD system.
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Affiliation(s)
- Wei-Jie Chen
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan
| | - I-Shih Ko
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan
| | - Chi-An Lin
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan
| | - Chun-Jen Chen
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan
| | - Jiun-Shian Wu
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan
| | - C K Chan
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan
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Yuen SKK, Bower W, Ng CF, Chiu PKF, Teoh JYC, Li CSY, Kwok HSW, Chan CK, Hou SSM. Cross-cultural translation into Chinese and psychometric evaluation of a screening tool for nocturia: the Targeting the individual's Aetiology of Nocturia to Guide Outcomes (TANGO) questionnaire. Hong Kong Med J 2023; 29:311-321. [PMID: 37532669 DOI: 10.12809/hkmj219261] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023] Open
Abstract
INTRODUCTION We conducted translation and psychometric validation of a self-administered, 22-item dichotomous response-based questionnaire to identify nocturia aetiologies and co-morbidities in adult patients. METHODS The Targeting the individual's Aetiology of Nocturia to Guide Outcomes (TANGO) questionnaire was forward- and backward-translated, then finalised using a standardised methodology. The resulting version, a Chinese version of the TANGO [TANGO (CV)], was evaluated for internal consistency, test-retest reliability, content validity, convergent validity, criterion validity, and discriminant validity via responses from 65 participants (46 men and 19 women; mean age, 67 years, range, 50-88), in comparison with other validated questionnaires and a 4-day bladder/sleep diary. RESULTS Only 0.4% of responses were missing; 3% of participants required assistance with comprehension. The Kuder-Richardson Formula 20 (KR-20) coefficient for the whole tool was 0.711. Kappa values for individual domains and the whole tool varied from 0.871 to 0.866, indicating satisfactory test-retest reliability. There was strong agreement between the sum of positive responses to each domain and the whole tool (intra-class correlation coefficient=0.878-1.000). Modest correlations (ρ=0.4-0.6) were detected between the tool and bladder/sleep diary-based parameters for convergent validity. Criterion validity was confirmed for each domain and the whole tool [ρ=0.287-0.687]. In receiver operating characteristic analysis, the tool could distinguish patients (≥2 nocturia episodes/night) from controls (≤1 nocturia episode/night) [Youden's J statistic=0.453, area under the curve=0.818, 95% confidence interval (CI)=0.683-0.953] and patients with significant nocturia distress from patients with mild nocturia distress (Youden's J statistic=0.398, area under the curve=0.729, 95% CI=0.581-0.878). CONCLUSION The TANGO (CV) was formally crossculturally adapted and translated. Its psychometric properties (except sensitivity to change) were validated.
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Affiliation(s)
- S K K Yuen
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - W Bower
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - C F Ng
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - P K F Chiu
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - J Y C Teoh
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - C S Y Li
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - H S W Kwok
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - C K Chan
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - S S M Hou
- SH Ho Urology Centre, Division of Urology, Department of Surgery, The Chinese University of Hong Kong, Hong Kong SAR, China
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Poon DMC, Chan CK, Chan K, Chu WH, Kwong PWK, Lam W, Law KS, Lee EKC, Liu PL, Sze HCK, Wong JHM, Chan ESY. Recommendations for the management of advanced and metastatic renal cell carcinoma: joint consensus statements from the Hong Kong Urological Association and the Hong Kong Society of Uro-Oncology. Hong Kong Med J 2022; 28:475-481. [PMID: 35815480 DOI: 10.12809/hkmj219727] [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: 02/01/2023] Open
Abstract
INTRODUCTION Kidney cancer, primarily renal cell carcinoma (RCC), ranks among the top 10 most common malignancies in the male population of Hong Kong. In 2019, members of two medical societies in Hong Kong formed an expert panel to establish a set of consensus statements for the management of metastatic RCC. On 22 June 2021, the same panel met to review recent evidence and reassess their positions regarding the management of advanced and metastatic RCC, with the aim of providing recommendations for physicians in Hong Kong. PARTICIPANTS The panel included 12 experts (6 clinical oncologists and 6 urologists) who had extensive experience managing patients with RCC in Hong Kong. EVIDENCE The panel reviewed randomised controlled trials, observational studies, systematic reviews/meta-analyses, and international clinical guidelines to address key clinical questions that were identified before the meeting. CONSENSUS PROCESS In total, 15 key clinical questions were identified before the meeting, covering the surgical and systemic treatment of advanced or metastatic clear cell, sarcomatoid, and non-clear cell RCCs. At the meeting, the panellists voted on these questions, then discussed relevant evidence and practical considerations. CONCLUSIONS The treatment landscape for advanced and metastatic RCC continues to evolve. More immune checkpoint inhibitor (ICI)-based combination regimens will be indicated for the treatment of metastatic clear cell RCC. There is increasing evidence concerning the benefit of adjuvant ICI treatment for resected advanced RCC. This article summarises recent evidence and expert insights regarding a series of key clinical questions about the management of advanced and metastatic RCC.
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Affiliation(s)
- D M C Poon
- Hong Kong Society of Uro-Oncology, Hong Kong
| | - C K Chan
- Hong Kong Urological Association, Hong Kong
| | - K Chan
- Hong Kong Society of Uro-Oncology, Hong Kong
| | - W H Chu
- Hong Kong Urological Association, Hong Kong
| | - P W K Kwong
- Hong Kong Society of Uro-Oncology, Hong Kong
| | - W Lam
- Hong Kong Urological Association, Hong Kong
| | - K S Law
- Hong Kong Society of Uro-Oncology, Hong Kong
| | - E K C Lee
- Hong Kong Society of Uro-Oncology, Hong Kong
| | - P L Liu
- Hong Kong Urological Association, Hong Kong
| | - H C K Sze
- Hong Kong Society of Uro-Oncology, Hong Kong
| | - J H M Wong
- Hong Kong Urological Association, Hong Kong
| | - E S Y Chan
- Hong Kong Urological Association, Hong Kong
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Chan CK, Wong RSM, Chan JCM, Chong YK, Au Yeung J, Yung TH. Liver injury associated with the use of health supplement HemoHIM. Hong Kong Med J 2022; 28:413-414. [PMID: 38232970 DOI: 10.12809/hkmj219950] [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: 11/07/2022] Open
Affiliation(s)
- C K Chan
- Hong Kong Poison Information Centre, United Christian Hospital, Hong Kong
| | - R S M Wong
- Prince of Wales Hospital Poison Treatment Centre, Hong Kong
| | - J C M Chan
- Prince of Wales Hospital Poison Treatment Centre, Hong Kong
| | - Y K Chong
- Hospital Authority Toxicology Reference Laboratory, Hong Kong
| | - J Au Yeung
- Hospital Authority Chief Pharmacist's Office, Hong Kong
| | - T H Yung
- Hospital Authority Chief Pharmacist's Office, Hong Kong
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Sun C, Lin KC, Yeung CY, Ching ESC, Huang YT, Lai PY, Chan CK. Revealing directed effective connectivity of cortical neuronal networks from measurements. Phys Rev E 2022; 105:044406. [PMID: 35590680 DOI: 10.1103/physreve.105.044406] [Citation(s) in RCA: 1] [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] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 03/23/2022] [Indexed: 06/15/2023]
Abstract
In the study of biological networks, one of the major challenges is to understand the relationships between network structure and dynamics. In this paper, we model in vitro cortical neuronal cultures as stochastic dynamical systems and apply a method that reconstructs directed networks from dynamics [Ching and Tam, Phys. Rev. E 95, 010301(R) (2017)2470-004510.1103/PhysRevE.95.010301] to reveal directed effective connectivity, namely, the directed links and synaptic weights, of the neuronal cultures from voltage measurements recorded by a multielectrode array. The effective connectivity so obtained reproduces several features of cortical regions in rats and monkeys and has similar network properties as the synaptic network of the nematode Caenorhabditis elegans, whose entire nervous system has been mapped out. The distribution of the incoming degree is bimodal and the distributions of the average incoming and outgoing synaptic strength are non-Gaussian with long tails. The effective connectivity captures different information from the commonly studied functional connectivity, estimated using statistical correlation between spiking activities. The average synaptic strengths of excitatory incoming and outgoing links are found to increase with the spiking activity in the estimated effective connectivity but not in the functional connectivity estimated using the same sets of voltage measurements. These results thus demonstrate that the reconstructed effective connectivity can capture the general properties of synaptic connections and better reveal relationships between network structure and dynamics.
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Affiliation(s)
- Chumin Sun
- Institute of Theoretical Physics and Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - K C Lin
- Institute of Theoretical Physics and Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - C Y Yeung
- Institute of Theoretical Physics and Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Emily S C Ching
- Institute of Theoretical Physics and Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Yu-Ting Huang
- Department of Physics and Center for Complex Systems, National Central University, Chungli, Taiwan 320, ROC
- Institute of Physics, Academia Sinica, Taipei, Taiwan 115, ROC
| | - Pik-Yin Lai
- Department of Physics and Center for Complex Systems, National Central University, Chungli, Taiwan 320, ROC
| | - C K Chan
- Institute of Physics, Academia Sinica, Taipei, Taiwan 115, ROC
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Chan TT, Leung WCY, Chan CK, Lo HKT, Tso WWY, Tsui SH, Chan TSY, Chang RSK. Clinical experience in diagnosis and management of acquired methaemoglobinaemia: a case report and retrospective review. Hong Kong Med J 2021; 27:366-369. [PMID: 34706989 DOI: 10.12809/hkmj209028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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)
- T T Chan
- Accident and Emergency Department, Queen Mary Hospital, Hong Kong
| | - W C Y Leung
- Department of Medicine, Queen Mary Hospital, Hong Kong
| | - C K Chan
- Clinical Toxicology Department, United Christian Hospital, Hong Kong
| | - H K T Lo
- Department of Paediatrics, Kwong Wah Hospital, Hong Kong
| | - W W Y Tso
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong
| | - S H Tsui
- Accident and Emergency Department, Queen Mary Hospital, Hong Kong
| | - T S Y Chan
- Department of Medicine, Queen Mary Hospital, Hong Kong
| | - R S K Chang
- Department of Medicine, Queen Mary Hospital, Hong Kong
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Lin QR, Chou PY, Chan CK. Information synergy in the anticipatory dynamics of a retina. Phys Rev E 2021; 104:034420. [PMID: 34654118 DOI: 10.1103/physreve.104.034420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 09/09/2021] [Indexed: 11/07/2022]
Abstract
Anticipation is the phenomenon in which the response of a system is predictive of the stimulation. The encoding of stochastic light intensity (x) into spikes is investigated in an experiment with retinas from bullfrogs to understand the mechanism of anticipation of a retina. Partial information decomposition of the mutual information between the spike rates and the joint state {x,x[over ̇]} is found to be consistent with the encoding by the linear combination of x and x[over ̇] where x[over ̇] is the rate of change of x. This spike rate encoding form indicates that a retina is capable of anticipation based on the synergistic information generation between x and x[over ̇]. Our results suggest that illusions such as the anticipation studied here during retinal perception can originate from the recombination of information extracted in the retinal network.
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Affiliation(s)
- Qi-Rong Lin
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan.,Department of Physics, National Taiwan University, Taipei 106, Taiwan
| | - Po-Yu Chou
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan.,Department of Physics, National Central University, Taoyuan 320, Taiwan
| | - C K Chan
- Institute of Physics, Academia Sinica, Taipei 115, Taiwan.,Department of Physics, National Central University, Taoyuan 320, Taiwan
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Leung JSL, Poon VYK, Lam TYC, Chan CK, Chiu Y, Chu TY, Fung SKS, Ma WK. Ketamine-associated nephropathy treated with renal transplantation: a case report. Hong Kong Med J 2021; 27:219-221. [PMID: 34168089 DOI: 10.12809/hkmj208588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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)
- J S L Leung
- Department of Surgery, Princess Margaret Hospital, Hong Kong
| | - V Y K Poon
- Department of Surgery, Princess Margaret Hospital, Hong Kong
| | - T Y C Lam
- Department of Surgery, Princess Margaret Hospital, Hong Kong
| | - C K Chan
- Department of Surgery, Princess Margaret Hospital, Hong Kong
| | - Y Chiu
- Department of Surgery, Princess Margaret Hospital, Hong Kong
| | - T Y Chu
- Department of Surgery, Princess Margaret Hospital, Hong Kong
| | - S K S Fung
- Department of Medicine and Geriatrics, Princess Margaret Hospital, Hong Kong
| | - W K Ma
- Department of Surgery, Princess Margaret Hospital, Hong Kong
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Chou PY, Chien JF, Chen KS, Huang YT, Chen CC, Chan CK. Anticipation and negative group delay in a retina. Phys Rev E 2021; 103:L020401. [PMID: 33736006 DOI: 10.1103/physreve.103.l020401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/13/2021] [Indexed: 11/07/2022]
Abstract
The mechanism of negative group delay (NGD) is used to understand the anticipatory capability of a retina. Experiments with retinas from bullfrogs are performed to compare with the predictions of the NGD model. In particular, whole field stochastic stimulations with various autocorrelation times are used to probe anticipatory responses from the retina. We find that the NGD model can reproduce essential features of experimental observations characterized by the cross correlations between the stimulation and the retinal responses. Experiments with dark light pulse stimulations further support the NGD mechanism, with the retina producing time-advanced pulse responses. However, no time-advanced pulse responses are produced by bright pulses. Counterintuitively, the NGD model shows that it is the delay in the system which gives rise to anticipation because of the negative feedback adaptation mechanism.
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Affiliation(s)
- Po-Yu Chou
- Department of Physics, National Central University, Chungli District, Taoyuan 320, Taiwan, Republic of China
| | - Jo-Fan Chien
- Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan, Republic of China
| | - Kevin Sean Chen
- Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan, Republic of China
| | - Yu-Ting Huang
- Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan, Republic of China
| | - Chun-Chung Chen
- Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan, Republic of China
| | - C K Chan
- Department of Physics, National Central University, Chungli District, Taoyuan 320, Taiwan, Republic of China.,Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan, Republic of China
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Teh KH, Ruben JK, Chan CK, Abbas AA. Femoral Neck Non-Union - A Biomechanical Solution with Valgus Sliding Subtrochanteric Osteotomy: A Case Report. Malays Orthop J 2020; 14:134-137. [PMID: 32983389 PMCID: PMC7513664 DOI: 10.5704/moj.2007.022] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Avascular necrosis and non-union are two most dreaded complications of femoral neck fracture fixations. Hip replacement seems to be a simple solution for this complex problem. However, the long-term efficacy of prosthetic replacement in the young population with higher functional demand is still questionable. Femoral head preserving valgus subtrochanteric osteotomies in properly selected cases have strong support from literature. The conventional technique of valgus subtrochanteric osteotomy involves lateral based wedge resection. Alternatively, a simpler sliding oblique subtrochanteric osteotomy without any wedge removal can also be performed. We hereby describe a successful case of sliding subtrochanteric osteotomy with 135° dynamic hip screw (DHS) plate fixation in treating non-union neck of femur fracture in a young gentleman.
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Affiliation(s)
- K H Teh
- Department of Orthopaedic Surgery, Universiti Putra Malaysia, Serdang, Malaysia
| | - J K Ruben
- Department of Orthopaedic Surgery, Hospital Serdang, Kajang, Malaysia
| | - C K Chan
- Department of Orthopaedic Surgery, Mahkota Medical Centre, Malacca, Malaysia
| | - A A Abbas
- Department of Orthopaedic Surgery, University of Malaya, Kuala Lumpur, Malaysia
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Chou PY, Chiang WY, Chan CK, Lai PY. Dynamics of beating cardiac tissue under slow periodic drives. Phys Rev E 2020; 101:012201. [PMID: 32069621 DOI: 10.1103/physreve.101.012201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Indexed: 11/06/2022]
Abstract
Effects of mechanical coupling on cardiac dynamics are studied by monitoring the beating dynamics of a cardiac tissue which is being pulled periodically at a pace slower than its intrinsic beating rate. The tissue is taken from the heart of a bullfrog that includes pacemaker cells. The cardiac tissue beats spontaneously with an almost constant interbeat interval (IBI) when there is no external forcing. On the other hand, the IBI is observed to vary significantly under an external periodic drive. Interestingly, when the period of the external drive is about two times the intrinsic IBI of the tissue without pulling, the IBI as a function of time exhibits a wave packet structure. Our experimental results can be understood theoretically by a phase-coupled model under external driving. In particular, the theoretical prediction of the wave-packet period as a function of the normalized driving period agrees excellently with the observations. Furthermore, the cardiac mechanical coupling constant can be extracted from the experimental data from our model and is found to be insensitive to the external driving period. Implications of our results on cardiac physiology are also discussed.
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Affiliation(s)
- Po-Yu Chou
- Department of Physics, and Center for Complex Systems, National Central University, Chungli District, TaoYuan City 320, Taiwan, Republic of China
| | - Wei-Yin Chiang
- Department of Physics, and Center for Complex Systems, National Central University, Chungli District, TaoYuan City 320, Taiwan, Republic of China
| | - C K Chan
- Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan, Republic of China
| | - Pik-Yin Lai
- Department of Physics, and Center for Complex Systems, National Central University, Chungli District, TaoYuan City 320, Taiwan, Republic of China
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Koh SM, Chan CK, Teo SH, Singh S, Merican A, Ng WM, Abbas A, Kamarul T. Elevated plasma and synovial fluid interleukin-8 and interleukin-18 may be associated with the pathogenesis of knee osteoarthritis. Knee 2020; 27:26-35. [PMID: 31917106 DOI: 10.1016/j.knee.2019.10.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 10/06/2019] [Accepted: 10/31/2019] [Indexed: 02/02/2023]
Abstract
PURPOSE Osteoarthritis (OA) of the knee is a multifactorial degenerative disease typically defined as the 'wear and tear' of articular joint cartilage. However, recent studies suggest that OA is a disease arising from chronic low-grade inflammation. We conducted a study to investigate the relationship between chronic inflammatory mediators present in both the systemic peripheral blood system and localised inflammation in synovial fluid (SF) of OA and non-OA knees; and subsequently made direct comparative analyses to understand the mechanisms that may underpin the processes involved in OA. METHODS 20-Plex proteins were quantified using Human Magnetic Luminex® assay (R&D Systems, USA) from plasma and SF of OA (n = 14) and non-OA (n = 14) patients. Ingenuity Pathway Analysis (IPA) software was used to predict the relationship and possible interaction of molecules pertaining to OA. RESULTS There were significant differences in plasma level for matrix metalloproteinase (MMP)-3, interleukin (IL)-27, IL-8, IL-4, tumour necrosis factor-alpha, MMP-1, IL-15, IL-21, IL-10, and IL-1 beta between the groups, as well as significant differences in SF level for IL-15, IL-8, vascular endothelial growth factor (VEGF), MMP-1, and IL-18. Our predictive OA model demonstrated that toll-like receptor (TLR) 2, macrophage migration inhibitory factor (MIF), TLR4 and IL-1 were the main regulators of IL-1B, IL-4, IL-8, IL-10, IL-15, IL-21, IL-27, MMP-1 and MMP-3 in the plasma system; whilst IL-1B, TLR4, IL-1, and basigin (BSG) were the regulators of IL-4, IL-8, IL-10, IL-15, IL-18, IL-21, IL-27, MMP-1, and MMP-3 in the SF system. CONCLUSION The elevated plasma IL-8 and SF IL-18 may be associated with the pathogenesis of OA via the activation of MMP-3.
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Affiliation(s)
- S M Koh
- Tissue Engineering Group (TEG), Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - C K Chan
- Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - S H Teo
- Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - S Singh
- Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - A Merican
- Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - W M Ng
- Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - A Abbas
- Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - T Kamarul
- Tissue Engineering Group (TEG), Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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Alibekova R, Kadyrzhanuly K, Chan CK, An S, Gusmanov A, Yerubayev Z, Yessimkulova F, Bekisheva A, Ospanova Z, Rakhimova M. The impact of participation in support groups on mental health of parents having children with autism. Eur J Public Health 2019. [DOI: 10.1093/eurpub/ckz186.574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Introduction
Whilst there is accumulated evidence about the high prevalence of stress and mood disorders in parents of children with autism, few studies have shown that participating in parental support groups was associated with less mental health problems. This study was aimed to explore the association of participation in support groups with stress and mood disorders in parents of children with autism in Kazakhstan.
Methods
Participants (n = 146) were recruited to this cross-sectional survey from autism non-governmental organizations and Republican Children’s Rehabilitation Center in Nur-Sultan city during April-December 2018. A 59 item survey consisted of questions on parental socio-demographics, needs, participation in support groups, depression, anxiety and stress (DASS), and Multidimensional Scale of Perceived Social Support (MSPSS). Descriptive, bivariate and multivariate logistic regression analyses were performed in STATA 15.
Results
44.4% of parents reported experiencing stress, and almost half of the sample had elevated depressive (53.7%) and anxiety symptoms (47.4%). 45.3% of participants were members of parental organizations; there were no significant differences in the prevalence of stress and mood disorders among members and non-members of parental support groups. Results of the multivariate logistic regression showed that parents with older autistic children (OR 1.37, p-value 0.001), less family support (OR 0.894, p-value 0.044) and higher income (OR 3.01, p-value 0.025) were more likely to be members of support groups.
Conclusions
These findings indicate the need to increase support groups to under-served populations of Kazakhstan’s families with autistic children. Additional efforts are needed to strengthen the role of support groups in meeting the emotional needs of the parents.
Key messages
Parents of children with autism spectrum disorder experience elevated level of stress and mood disorders; however participation in support groups was not beneficial for relieving parental distress. Further research is warranted to explore the benefits of participation in support groups, and interventions are needed to strengthen the role of support groups in meeting the needs of parents.
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Affiliation(s)
- R Alibekova
- Department of Medicine, School of Medicine, Nazarbayev University, Nursultan, Kazakhstan
| | - K Kadyrzhanuly
- Department of Medicine, School of Medicine, Nazarbayev University, Nursultan, Kazakhstan
| | - C K Chan
- Department of Biomedical Sciences, Nazarbayev University, Nursultan, Kazakhstan
| | - S An
- School of Humanities and Social Sciencies, Nazarbayev University, Nursultan, Kazakhstan
| | - A Gusmanov
- Master of Public Health Program, School of Medicine, Nazarbayev University, Nursultan, Kazakhstan
| | - Z Yerubayev
- Master of Public Health Program, School of Medicine, Nazarbayev University, Nursultan, Kazakhstan
| | - F Yessimkulova
- Master of Public Health Program, School of Medicine, Nazarbayev University, Nursultan, Kazakhstan
| | - A Bekisheva
- Master of Public Health Program, School of Medicine, Nazarbayev University, Nursultan, Kazakhstan
| | - Z Ospanova
- Master of Public Health Program, School of Medicine, Nazarbayev University, Nursultan, Kazakhstan
| | - M Rakhimova
- Master of Public Health Program, School of Medicine, Nazarbayev University, Nursultan, Kazakhstan
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Lun KW, Chan CK, Ip PK, Ma SY, Tsai WW, Wong CS, Wong CH, Wong TW, Yan D. Depression and anxiety among university students in Hong Kong. Hong Kong Med J 2019; 24:466-472. [PMID: 30245480 DOI: 10.12809/hkmj176915] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [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 Entry into tertiary education is a critical juncture where adolescents proceed to adulthood. This study aimed to determine the prevalence of depression and anxiety, and factors associated with such symptoms, among university undergraduate students in Hong Kong. METHODS A cross-sectional questionnaire study was employed. A total of 1200 undergraduate students from eight University Grants Committee-funded universities were invited to complete three sets of questionnaires, including the 9-item patient health questionnaire for screening of depressive symptoms, the 7-item generalised anxiety disorder scale for screening of anxiety symptoms, and a socio-demographic questionnaire. RESULTS Among the valid responses (n=1119) analysed, 767 (68.5%) respondents indicated mild to severe depressive symptoms, which were associated with mild to severe anxiety symptoms. Several lifestyle and psychosocial variables, including regular exercise, self-confidence, satisfaction with academic performance, and optimism towards the future were inversely related with mild to severe depressive symptoms. A total of 599 (54.4%) respondents indicated mild to severe anxiety symptoms, which were associated with level of academic difficulty. Satisfaction with friendship, sleep quality, and self-confidence were inversely associated with mild to severe anxiety symptoms. CONCLUSION More than 50% of respondents expressed some degree of depressive and anxiety symptoms (68.5% and 54.4%, respectively). Approximately 9% of respondents exhibited moderately severe to severe depressive symptoms; 5.8% exhibited severe anxiety symptoms. Respondents reporting regular exercise, higher self-confidence, and better satisfaction with both friendship and academic performance had fewer depressive and anxiety symptoms.
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Affiliation(s)
- K Wc Lun
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - C K Chan
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - P Ky Ip
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - S Yk Ma
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - W W Tsai
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - C S Wong
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | - C Ht Wong
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
| | | | - D Yan
- Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong
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Chan CK, Wong KH, Lee MP, Chan KC, Leung CC, Leung EC, Chan WK, Mak IK. Risk factors associated with 1-year mortality among patients with HIV-associated tuberculosis in areas with intermediate tuberculosis burden and low HIV prevalence. Hong Kong Med J 2019; 24:473-483. [PMID: 30262675 DOI: 10.12809/hkmj187303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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 Data are limited regarding risk factors for mortality among patients with human immunodeficiency virus (HIV)-associated tuberculosis (TB) in areas with low HIV prevalence and intermediate TB burden, such as the Western Pacific region. This study aimed to assess such risk factors in Hong Kong, which has an intermediate TB burden and low HIV prevalence. METHODS We conducted a retrospective cohort analysis of adult patients reported to the Hong Kong TB-HIV Registry between 2006 and 2015. Baseline characteristics were compared with Kaplan-Meier estimates. Cox proportional hazards regression modelling was used to identify factors associated with mortality. RESULTS Of 299 patients studied, 21 (7.0%) died within 12 months of anti-TB treatment (median [interquartile range], 7.5 [3.8-10] months). The median age of death was 54 (interquartile range, 40.5-75.0) years. The cause of death was TB in five and unrelated to TB in the remaining 16. Cox proportional hazards regression showed that older age (adjusted hazard ratio=4.5; 95% confidence interval [CI]=1.4-14.9), history of drug addiction (4.6; 95% CI=1.6-13.0), and low baseline CD4 cell count of <50/μL (2.9; 95% CI=1.1-7.7) were independent risk factors for death within 12 months. CONCLUSION This study complements previous studies by providing information regarding risk factors associated with mortality among patients with HIV-associated TB in areas with intermediate TB burden and low HIV prevalence. The results from our study may guide targeted measures to improve survival in other areas with intermediate TB burden and low HIV prevalence, such as the Western Pacific region.
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Affiliation(s)
- C K Chan
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - K H Wong
- Head Office, Centre for Health Protection, Department of Health, Hong Kong
| | - M P Lee
- Department of Medicine, Queen Elizabeth Hospital, Hospital Authority, Hong Kong
| | - K Cw Chan
- Integrated Treatment Centre, Special Preventive Programme, Centre for Health Protection, Department of Health, Hong Kong
| | - C C Leung
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - E Cc Leung
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - W K Chan
- Integrated Treatment Centre, Special Preventive Programme, Centre for Health Protection, Department of Health, Hong Kong
| | - I Ky Mak
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
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Li AM, Fung CKC, Yu ITS, Goggins WB, Chan GYS, Chan CK, Lau APS, Leung JOS. Associations of wheeze during the first 18 months of life with indoor nitrogen dioxide, formaldehyde, and family history of asthma: a prospective cohort study. Hong Kong Med J 2019; 25 Suppl 3:20-23. [PMID: 30792368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023] Open
Affiliation(s)
- A M Li
- The Chinese University of Hong Kong
| | | | - I T S Yu
- The Chinese University of Hong Kong
| | | | | | - C K Chan
- Hong Kong University of Science and Technology
| | - A P S Lau
- Hong Kong University of Science and Technology
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Abstract
Racemic bupivacaine is the most common local anaesthetic used intrathecally. This prospective, randomized, double-blind study compared the clinical efficacy and motor block of 0.5% levobupivacaine with 0.5% racemic bupivacaine in spinal anaesthesia for urological surgery. The surgery required an upper level of sensory block of at least the tenth thoracic dermatome. Fifty patients were recruited (levobupivacaine group n=24; bupivacaine group n=26). Spinal anaesthesia was achieved with 2.6 ml of study solution injected in the subarachnoid space at the lumbar 3/4 interspace. One patient from the levobupivacaine group was excluded due to technical failure. There were no significant differences between the two groups in the quality of sensory and motor block or in haemodynamic change. Anaesthesia was adequate and patient satisfaction good in all cases. We conclude that 0.5% levobupivacaine can be used as an alternative to 0.5% racemic bupivacaine in spinal anaesthesia for surgery when a sensory block to at least T10 is required.
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Affiliation(s)
- Y Y Lee
- Department of Anaesthesiology and Operating Theatre Services, Kwong Wah Hospital, Hong Kong, S.A.R
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18
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Yee CH, Chan CK, Teoh JYC, Chiu PKF, Wong JHM, Chan ESY, Hou SSM, Ng CF. Survey on prevalence of lower urinary tract symptoms in an Asian population. Hong Kong Med J 2019; 25:13-20. [PMID: 30655460 DOI: 10.12809/hkmj187502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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 Lower urinary tract symptoms (LUTS) have a strong effect on socio-economic and individual quality of life. The aim of the present study was to investigate the prevalence of LUTS in an Asian population. METHODS A telephone survey of individuals aged ≥40 years and of Chinese ethnicity was conducted. The survey included basic demographics, medical and health history, drinking habits, International Prostate Symptom Score, overactive bladder symptom score, Patient Health Questionnaire (PHQ-9) score, and Short Form (SF)-12v2 score. RESULTS From March to May 2017, 18 881 calls were made, of which 1543 fulfilled the inclusion criteria. In the end, 1000 successful respondents were recruited (302 men and 698 women). Age-adjusted prevalence of overactive bladder syndrome was 15.1%. The older the respondent, the more prevalent the storage symptoms and voiding symptoms (storage symptoms: r=0.434, P<0.001; voiding symptom: r=0.190, P<0.001). Presence of hypertension and diabetes were found to be significantly and positively correlated with storage and voiding symptoms. Storage and voiding symptoms were found to affect PHQ-9 scores (storage symptoms: r=0.257, P<0.001; voiding symptoms: r=0.275, P<0.001) and SF-12v2 scores (storage symptoms: r=0.467, P<0.001; voiding symptoms: r=0.335; P<0.001). Nocturia was the most prominent symptom among patients who sought medical help for their LUTS. CONCLUSIONS Lower urinary tract symptoms are common in Asian populations. Both storage and voiding symptoms have a negative impact on mental health and general well-being of individuals.
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Affiliation(s)
- C H Yee
- SH Ho Urology Centre, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - C K Chan
- SH Ho Urology Centre, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - J Y C Teoh
- SH Ho Urology Centre, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - P K F Chiu
- SH Ho Urology Centre, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - J H M Wong
- SH Ho Urology Centre, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - E S Y Chan
- SH Ho Urology Centre, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - S S M Hou
- SH Ho Urology Centre, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - C F Ng
- SH Ho Urology Centre, The Chinese University of Hong Kong, Shatin, Hong Kong
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Reed MJ, Damodarasamy M, Pathan JL, Chan CK, Spiekerman C, Wight TN, Banks WA, Day AJ, Vernon RB, Keene CD. Increased Hyaluronan and TSG-6 in Association with Neuropathologic Changes of Alzheimer's Disease. J Alzheimers Dis 2019; 67:91-102. [PMID: 30507579 PMCID: PMC6398602 DOI: 10.3233/jad-180797] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [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] [Indexed: 01/08/2023]
Abstract
Little is known about the extracellular matrix (ECM) during progression of AD pathology. Brain ECM is abundant in hyaluronan (HA), a non-sulfated glycosaminoglycan synthesized by HA synthases (HAS) 1-3 in a high molecular weight (MW) form that is degraded into lower MW fragments. We hypothesized that pathologic severity of AD is associated with increases in HA and HA-associated ECM molecules. To test this hypothesis, we assessed HA accumulation and size; HA synthases (HAS) 1-3; and the HA-stabilizing hyaladherin, TSG-6 in parietal cortex samples from autopsied research subjects with not AD (CERAD = 0, Braak = 0- II, n = 12-21), intermediate AD (CERAD = 2, Braak = III-IV, n = 13-18), and high AD (CERAD = 3, Braak = V-VI, n = 32-40) neuropathologic change. By histochemistry, HA was associated with deposits of amyloid and tau, and was also found diffusely in brain parenchyma, with overall HA quantity (measured by ELSA) significantly greater in brains with high AD neuropathology. Mean HA MW was similar among the samples. HAS2 and TSG-6 mRNA expression, and TSG-6 protein levels were significantly increased in high AD and both molecules were present in vasculature, NeuN-positive neurons, and Iba1-positive microglia. These results did not change when accounting for gender, advanced age (≥ 90 years versus <90 years), or the clinical diagnosis of dementia. Collectively, our results indicate a positive correlation between HA accumulation and AD neuropathology, and suggest a possible role for HA synthesis and metabolism in AD progression.
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Affiliation(s)
- MJ Reed
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA
| | - M Damodarasamy
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA
| | - JL Pathan
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA
| | - CK Chan
- Matrix Biology Program, Benaroya Research Institute, Virginia Mason, Seattle, WA, USA
| | - C Spiekerman
- Center for Biomedical Statistics, Institute for Translational Health Sciences, University of Washington, Seattle, WA, USA
| | - TN Wight
- Matrix Biology Program, Benaroya Research Institute, Virginia Mason, Seattle, WA, USA
| | - WA Banks
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA
- VA Puget Sound Health Care System, Geriatric Research Education and Clinical Center, Seattle, WA, USA
| | - AJ Day
- Wellcome Trust Centre for Cell-Matrix Research, Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - RB Vernon
- Matrix Biology Program, Benaroya Research Institute, Virginia Mason, Seattle, WA, USA
| | - CD Keene
- Department of Pathology, Division of Neuropathology, University of Washington, Seattle, WA, USA
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Leung EC, Leung CC, Chang KC, Chan CK, Mok TY, Chan KS, Lau KS, Chau CH, Yee WK, Law WS, Lee SN, Au KF, Tai LB, Leung WM. Delayed diagnosis of tuberculosis: risk factors and effect on mortality among older adults in Hong Kong. Hong Kong Med J 2018; 24:361-368. [PMID: 30065120 DOI: 10.12809/hkmj177081] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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
OBJECTIVE To assess the risk factors and effects of delayed diagnosis on tuberculosis (TB) mortality in Hong Kong. METHODS All consecutive patients with TB notified in 2010 were tracked through their clinical records for treatment outcome until 2012. All TB cases notified or confirmed after death were identified for a mortality survey on the timing and causes of death. RESULTS Of 5092 TB cases notified, 1061 (20.9%) died within 2 years of notification; 211 (4.1%) patients died before notification, 683 (13.4%) died within the first year, and 167 (3.3%) died within the second year after notification. Among the 211 cases with TB notified after death, only 30 were certified to have died from TB. However, 52 (24.6%) died from unspecified pneumonia/sepsis possibly related to pulmonary TB. If these cases are counted, the total TB-related deaths increases from 191 to 243. In 82 (33.7%) of these, TB was notified after death. Over 60% of cases in which TB diagnosed after death involved patients aged ≥80 years and a similar proportion had an advance care directive against resuscitation or investigation. Independent factors for TB notified after death included female sex, living in an old age home, drug abuse, malignancy other than lung cancer, sputum TB smear negative, sputum TB culture positive, and chest X-ray not done. CONCLUSIONS High mortality was observed among patients with TB aged ≥80 years. Increased vigilance is warranted to avoid delayed diagnosis and reduce the transmission risk, especially among elderly patients with co-morbidities living in old age homes.
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Affiliation(s)
- E C Leung
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - C C Leung
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - K C Chang
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - C K Chan
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - T Y Mok
- Respiratory Medicine Department, Kowloon Hospital, Homantin, Hong Kong
| | - K S Chan
- Pulmonary Service, Department of Medicine, Haven of Hope Hospital, Tseung Kwan O, Hong Kong
| | - K S Lau
- Respiratory Medicine Department, Ruttonjee Hospital, Wanchai, Hong Kong
| | - C H Chau
- Tuberculosis and Chest Unit, Grantham Hospital, Wong Chuk Hang, Hong Kong
| | - W K Yee
- Department of Medicine and Geriatrics, Kwong Wah Hospital, Hong Kong
| | - W S Law
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - S N Lee
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - K F Au
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - L B Tai
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
| | - W M Leung
- Tuberculosis and Chest Service, Centre for Health Protection, Department of Health, Hong Kong
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Abstract
Purpose To describe the unusual complication of retinal pigment epithelial (RPE) tear after intravitreal ranibizumab (Lucentis®) for subfoveal fibrovascular pigment epithelial detachment (PED) and its effective management. Methods Chart review for case report of RPE tear after ranibizumab. Results An inferior RPE tear was documented by fluorescein angiography, fundus photography, and optical coherence tomography (OCT) 1 month after receiving repeat ranibizumab injection in the right eye of a patient with bilateral subfoveal fibrovascular PED. He had undergone multiple bevacizumab followed by ranibizumab injections for neovascular age-related macular degeneration (AMD) in both eyes, starting 6 months previously. Subsequent antivascular endothelial growth factor (VEGF) therapy improved vision of right eye from 20/200 to 20/40, despite RPE tear. Conclusions RPE tear may form after anti-VEGF therapy, including ranibizumab injection. Further anti-VEGF therapy may preserve or improve vision. To the authors' knowledge, this is first case report of effective suppression of neovascular activity with bevacizumab after an RPE tear following ranibizumab therapy.
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Affiliation(s)
- C K Chan
- Southern California Desert Retina Consultants, Palm Springs, CA 92263, USA.
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22
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Chan CK, Chan YC, Lau FL. A Case of Methanol Poisoning. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790701400206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A 29-year-old male took about 300 ml industrial alcohol in a suicidal attempt. The industrial alcohol was later confirmed to be methanol. He presented to the emergency department 10 hours post-ingestion with an anion gap metabolic acidosis and an osmol gap of 76.7 mOsm/kg. Ethanol infusion was started in the emergency department at 11 hours post-ingestion before the availability of serum methanol level. The clinical diagnosis of toxic alcohol ingestion was based on the history, arterial blood gases results and the presence of a significant osmol gap. The patient was then admitted to the intensive care unit for ethanol therapy and haemodialysis. Prompt initiation of ethanol therapy and the subsequent intensive care prevented the development of life-threatening complications of methanol poisoning in this case.
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Affiliation(s)
| | | | - FL Lau
- United Christian Hospital, Hong Kong Poison Information Centre, 130 Hip Wo Street, Kwun Tong, Kowloon, Hong Kong
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Choi KM, Chan CK, Lau FL. Toxicology Training Unit in Emergency Department Reduces Admission to other Specialties and Hospital Length of Stay. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490791602300601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objective To evaluate the outcome of intoxicated patients presented to Accident and Emergency Department (AED) in Hong Kong with Toxicology Training Unit accreditation and AED without toxicology team. Method A retrospective observational study with data collection from all intoxicated cases reported through Pre-hospital Activated Charcoal Programme, a protocol driven poisoning reporting system, from 1/7/2011 to 30/6/2013 (2 years). Data on basic demographic data (e.g. sex, age), receiving AED, admission rate to other specialty, length of stay in hospital exclude psychiatry ward admission and clinical outcome were collected and analysed. Five AEDs with Toxicology Training Unit (study group) and 7 AEDs without toxicology team (control group) were included. Results A total of 329 intoxicated cases were included in this study. The basic epidemiological data were similar in both groups. There was a significantly lower in hospital admissions in study group (16.9%) than in control group (69.3%; p<0.001) and significant shorter median of hospital stay of 22.1 hours (interquartile range [IQR] 12.8-43.5 hours) in study group compare to 42.7 hours (IQR 20.4-76.1 hours) in control group (p<0.001). Conclusion Our findings show that the establishment of the toxicology training unit can achieve significant reduction in admissions to other specialty and the length of stay in hospital in the management of patients with acute intoxication.
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Abstract
Objective Hot water immersion (HWI) has been proven to be effective for the treatment of pain due to marine envenomation. Our preliminary study by simply measuring the temperature change over time on the hot water in our conventional metal tray method revealed a too rapid fall in water temperature that happened in minutes. The aim of this study was to review the current practice of HWI for patients with marine envenomation in the emergency departments in Hong Kong, and to look for the optimal equipment in performing HWI. Method We first conducted a phone survey to 16 registered nurses or nursing officers from 16 emergency departments of public hospitals in Hong Kong for the current practice of hot water immersion. The second part of our study was an in-vitro experiment done in observation room that a healthy subject immersed a hand into the water bath in metallic tray, sharp box and thermal isolator with and without covering of aluminum foil or plastic foil. The temperature change of the water bath in these containers was serially monitored. Results In our phone survey, 14 respondents used plastic tray or sharp box for hot water immersion. Nine of them claimed that they commonly encountered inadequate wound pain relief and early cooling of the hot water bath. The experiment showed that the water temperature dropped out of optimal range for 5 minutes and 15 minutes in metallic tray and sharp box respectively. The thermal isolator kept the optimal temperature throughout 30 minutes of the study time. Conclusion Our purposed thermal isolator is a safe, practical and effective device for HWI therapy.
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Affiliation(s)
| | - CK Chan
- United Christian Hospital, Hong Kong Poison Information Centre, K3A, 130 Hip Wo Street, Kwun Tong, Kowloon, Hong Kong
| | - ML Tse
- United Christian Hospital, Hong Kong Poison Information Centre, K3A, 130 Hip Wo Street, Kwun Tong, Kowloon, Hong Kong
| | - FL Lau
- United Christian Hospital, Hong Kong Poison Information Centre, K3A, 130 Hip Wo Street, Kwun Tong, Kowloon, Hong Kong
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Ho LY, Chan CK, Chu PS. Patient opinion of lower urinary tract symptoms and their treatment: a cross-sectional survey in Hong Kong public urology clinics. Hong Kong Med J 2017; 23:562-9. [PMID: 29026056 DOI: 10.12809/hkmj166102] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION Lower urinary tract symptoms collectively represent a common condition among ageing men. There are, however, limited data on the frequency of individual symptoms in patients who seek specialist care. We conducted a multinational survey in South-East Asia to evaluate patients' self-reported prevalence, bother, treatment, and treatment satisfaction of four lower urinary tract symptoms namely, urgency, nocturia, slow stream, and post-micturition dribble. This report presents the analysis of the Hong Kong subpopulation. METHODS This cross-sectional survey involved adult men aged over 18 years who attended a urology out-patient clinic because of lower urinary tract symptoms. A structured questionnaire, translated and validated in the local languages, was self-administered by patients. RESULTS Of 1436 respondents surveyed in the region, 225 were from Hong Kong of whom most were aged 56 to 75 years, retired, and had no history of any previous prostate surgery. Overall, the self-reported prevalence of nocturia of at least one void per night was 93% (95% confidence interval, 90%-97%), slow stream 76% (71%-82%), post-micturition dribble 70% (64%-76%), and urgency 50% (43%-56%). Symptoms for which most respondents reported "some" or "a lot" of bother included: nocturia, defined as at least two voids per night (77%), and urgency and post-micturition dribble (73%). Only 39% to 54% of patients had previously received treatment but were not entirely satisfied with it. An understanding of their condition remained suboptimal. CONCLUSIONS In Hong Kong, nocturia emerged as the most prevalent and one of the most bothersome symptoms among men who sought urologist care for lower urinary tract symptoms. Compared with the non-Hong Kong population, Hong Kong respondents tended to be highly symptomatic and bothered. They were, however, less likely to have received treatment and were generally less satisfied with previous treatment.
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Affiliation(s)
- L Y Ho
- Division of Urology, Department of Surgery, Queen Elizabeth Hospital, Jordan, Hong Kong
| | - C K Chan
- Division of Urology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - P Sk Chu
- Division of Urology, Department of Surgery, Tuen Mun Hospital, Tuen Mun, Hong Kong
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Ma KW, Chok KS, Chan CK, Dai WC, Sin SL, Lau FL, Chan SC, Lo CM. Liver transplantation: a life-saving procedure following amatoxin mushroom poisoning. Hong Kong Med J 2017; 23:93-6. [PMID: 28184019 DOI: 10.12809/hkmj154616] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- K W Ma
- Department of Surgery, Queen Mary Hospital, Pokfulam, Hong Kong
| | - K Sh Chok
- Department of Surgery, Queen Mary Hospital, Pokfulam, Hong Kong.,Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong
| | - C K Chan
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
| | - W C Dai
- Department of Surgery, Queen Mary Hospital, Pokfulam, Hong Kong.,Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong
| | - S L Sin
- Department of Surgery, Queen Mary Hospital, Pokfulam, Hong Kong
| | - F L Lau
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
| | - S C Chan
- Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong
| | - C M Lo
- Department of Surgery, Queen Mary Hospital, Pokfulam, Hong Kong.,Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong
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Chan CK, Timothy GF, Yeow CH. Comparison of mean frequency and median frequency in evaluating muscle fiber type selection in varying gait speed across healthy young adult individuals. Annu Int Conf IEEE Eng Med Biol Soc 2017; 2016:1725-1728. [PMID: 28268659 DOI: 10.1109/embc.2016.7591049] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The preferential slow and fast twitches fiber involvement in varying gait speed has not been thoroughly investigated. Attempt to classify fiber type in changing speed should be closely investigated and scrutinized as the histochemical-related experiments are cumbersome and time consuming. In addressing this issue, electromyography (EMG) is utilized to extract the muscle fiber type features by altering the muscle fatigue indices, namely mean frequency (MNF) and median frequency (MDF). Recently, there are no universal indices to determine the muscle type. In this paper, the MNF and MDF are employed in discovering the muscle type variation as the speed changes. Besides drawing the potential of MNF and MDF in unveiling the muscle type, both the parameters are applied to investigate the muscles that are recruited and which muscle type are involved as the gait velocity changes. In this study, six healthy and young participants are recruited, whereby the EMG sensors are placed on twelve lower extremity muscles. The EMG signals are then processed via Matlab software to deduce MNF and MDF. The MNF and MDF are determined from every of the phase gait, namely stance and swing. From the results obtained, it reveals that the superiority of the MNF over the MDF in determining and interpreting the muscle recruitment in both gait phases as the speed increases. The MNF, moreover, is able to show an apparent difference in muscle type selection compared to MDF. Interestingly, it is discovered that as the speed increases from slow to fast, the MNF decreases, which indicates that more muscle fiber type I is recruited. Contrarily, the MNF increases as the speed intensity decreases, which indicates that the distribution of muscle type II is prominent.
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Abstract
Probing a bullfrog retina with spatially uniform light pulses of correlated stochastic intervals, we calculate the mutual information between the spiking output at the ganglion cells measured with multi-electrode array (MEA) and the interval of the stimulus at a time shift later. The time-integrated information from the output about the future stimulus is maximized when the mean interval of the stimulus is within the dynamic range of the well-established anticipative phenomena of omitted-stimulus responses for the retina. The peak position of the mutual information as a function of the time shift is typically negative considering the processing delay of the retina. However, the peak position can become positive for long enough correlation time of the stimulus when the pulse intervals are generated by a Hidden Markovian model (HMM). This is indicative of a predictive behavior of the retina which is possible only when the hidden variable of the HMM can be recovered from the history of the stimulus for a prediction of its future. We verify that stochastic intervals of the same mean, variance, and correlation time do not result in the same predictive behavior of the retina when they are generated by an Ornstein-Uhlenbeck (OU) process, which is strictly Markovian.
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Affiliation(s)
- Kevin Sean Chen
- Institute of Physics, Academia SinicaTaipei, Taiwan.,Department of Life Science, National Taiwan UniversityTaipei, Taiwan
| | | | - C K Chan
- Institute of Physics, Academia SinicaTaipei, Taiwan.,Department of Physics and Center for Complex Systems, National Central UniversityChungli, Taiwan
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Ng CF, Yee CH, Chan CK, Wong HM, Chiu PK, Tsu JH, Teoh JY, Ho KL. Bipolar transurethral vapourisation versus monopolar transurethral resection of prostate: a randomised controlled trial. Hong Kong Med J 2017; 23 Suppl 2:32-34. [PMID: 29938669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023] Open
Affiliation(s)
- C F Ng
- Division of Urology, Department of Surgery, The Chinese University of Hong Kong
| | - C H Yee
- Division of Urology, Department of Surgery, The Chinese University of Hong Kong
| | - C K Chan
- Division of Urology, Department of Surgery, The Chinese University of Hong Kong
| | - H M Wong
- Division of Urology, Department of Surgery, The Chinese University of Hong Kong
| | - P Kf Chiu
- Division of Urology, Department of Surgery, The Chinese University of Hong Kong
| | - J Hl Tsu
- Division of Urology, Department of Surgery, The University of Hong Kong
| | - J Yc Teoh
- Division of Urology, Department of Surgery, The University of Hong Kong
| | - K L Ho
- Division of Urology, Department of Surgery, The University of Hong Kong
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Yu IT, Li AM, Goggins W, Leung JO, Chan GY, Fung CK, Chan CK, Lau AP. Association of wheeze during the first 18 months of life with indoor nitrogen dioxide, formaldehyde, and family history of asthma: a prospective cohort study. Hong Kong Med J 2017; 23 Suppl 2:19-23. [PMID: 29938666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023] Open
Affiliation(s)
- I Ts Yu
- The Chinese University of Hong Kong
| | - A M Li
- The Chinese University of Hong Kong
| | | | | | - G Ys Chan
- The Hong Kong Polytechnic University
| | | | - C K Chan
- Hong Kong University of Science and Technology
| | - A Ps Lau
- Hong Kong University of Science and Technology
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Park KS, Chan CK, Lee GW, Ahn HW, Yoon TR. Outcome of alternative approach to displaced acetabular fractures. Injury 2017; 48:388-393. [PMID: 27914663 DOI: 10.1016/j.injury.2016.11.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 08/30/2016] [Accepted: 11/26/2016] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Anatomical reduction of displaced acetabular fracture is not without its' limitations and complications. This study is conducted to assess clinical and radiological outcomes as well as complications of treating displaced acetabular fractures with emphasis on anatomical reduction in weight-bearing area, mainly the posterior column, and imperfect reduction of the anterior column is acceptable. However, stability of both columns is mandatory. METHODS It was a retrospective study carried out in a Level 1 arthroplasty and trauma centre. 23 patients (17 males, 6 females) with average age of 50.1 years (range, 36-68 years) with displaced acetabular fracture treated with combined incisions and plate-cable systems were included. There were 3 elementary and 18 associated fractures according to Letournel classification. Average follow-up was 23.5 months (range, 12-38.7 months). Mean operation time was 160min (range: 75-320min). Functional scores were evaluated using Harris Hip Score (HHS) whilst reduction was assessed by Matta criteria. Any displacement of reduction, osteoarthritis, heterotopic ossification, and other complications was recorded. RESULT 65.2% (15/23) of the patients obtained excellent HHS and 21.7% (5/23) had good HHS. There were 12 anatomical, 6 imperfect, and 5 poor reductions. No displacement was recorded in final follow-up. Complications documented: three lateral femoral cutaneous nerve injuries, two conversions to total hip arthroplasty, three Brooker stage 1 heterotrophic ossification, one pulmonary embolism and one screw irritation. No incidence of wound breakdown, infection and radiological osteoarthritis was reported. CONCLUSIONS Imperfect reduction of the anterior column provided clinical outcomes that are as good as total anatomical reduction. This approach minimizes soft tissue damage and reduces perioperative morbidities.
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Affiliation(s)
- K S Park
- Center for Joint Disease, Chonnam National University Hwasun Hospital, 160, Ilsim-Ri, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, South Korea
| | - C K Chan
- Center for Joint Disease, Chonnam National University Hwasun Hospital, 160, Ilsim-Ri, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, South Korea; NOCERAL, Department of Orthopaedic Surgery, Faculty of Medicine, University Malaya, 59100 Kuala Lumpur, Malaysia
| | - G W Lee
- Center for Joint Disease, Chonnam National University Hwasun Hospital, 160, Ilsim-Ri, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, South Korea
| | - H W Ahn
- Center for Joint Disease, Chonnam National University Hwasun Hospital, 160, Ilsim-Ri, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, South Korea
| | - T R Yoon
- Center for Joint Disease, Chonnam National University Hwasun Hospital, 160, Ilsim-Ri, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, South Korea.
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Huang CH, Huang YT, Chen CC, Chan CK. Propagation and synchronization of reverberatory bursts in developing cultured networks. J Comput Neurosci 2016; 42:177-185. [PMID: 27942935 DOI: 10.1007/s10827-016-0634-4] [Citation(s) in RCA: 3] [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] [Received: 05/20/2016] [Revised: 11/14/2016] [Accepted: 11/21/2016] [Indexed: 11/30/2022]
Abstract
Developing networks of neural systems can exhibit spontaneous, synchronous activities called neural bursts, which can be important in the organization of functional neural circuits. Before the network matures, the activity level of a burst can reverberate in repeated rise-and-falls in periods of hundreds of milliseconds following an initial wave-like propagation of spiking activity, while the burst itself lasts for seconds. To investigate the spatiotemporal structure of the reverberatory bursts, we culture dissociated, rat cortical neurons on a high-density multi-electrode array to record the dynamics of neural activity over the growth and maturation of the network. We find the synchrony of the spiking significantly reduced following the initial wave and the activities become broadly distributed spatially. The synchrony recovers as the system reverberates until the end of the burst. Using a propagation model we infer the spreading speed of the spiking activity, which increases as the culture ages. We perform computer simulations of the system using a physiological model of spiking networks in two spatial dimensions and find the parameters that reproduce the observed resynchronization of spiking in the bursts. An analysis of the simulated dynamics suggests that the depletion of synaptic resources causes the resynchronization. The spatial propagation dynamics of the simulations match well with observations over the course of a burst and point to an interplay of the synaptic efficacy and the noisy neural self-activation in producing the morphology of the bursts.
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Affiliation(s)
- Chih-Hsu Huang
- Institute of Physics, Academia Sinica, Nangang, Taipei, Taiwan, 115, Republic of China
| | - Yu-Ting Huang
- Institute of Physics, Academia Sinica, Nangang, Taipei, Taiwan, 115, Republic of China.,Department of Physics and Center for Complex Systems, National Central University, Chungli, Taiwan, 320, Republic of China
| | - Chun-Chung Chen
- Institute of Physics, Academia Sinica, Nangang, Taipei, Taiwan, 115, Republic of China.
| | - C K Chan
- Institute of Physics, Academia Sinica, Nangang, Taipei, Taiwan, 115, Republic of China.,Department of Physics and Center for Complex Systems, National Central University, Chungli, Taiwan, 320, Republic of China
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Abstract
Multicentric disappearing bone disease, or Gorham disease, is a rare entity. A middle age woman, presented to us with left sided antalgic gait and severe bony deformity of her left knee. Radiograph revealed massive bone defect of the medial condyle of the left tibia with subluxation of the knee joint. She was scheduled for knee replacement in six months. However, she developed another lesion over the right hip that typically mimicked the disease progression of disappearing bone disease. The right femoral head vanished progressively within three months without significant history of infection or trauma. Subsequent bone biopsy of the right femoral head and left tibia condyle confirmed the diagnosis. Total knee replacement was carried out for her left knee. She remained pain free on her left knee. A year later, after confirming by sequential radiographs that the osteolysis had stopped, total right hip replacement was performed. Five years later, she remained pain free and both the arthroplasties were stable.
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Affiliation(s)
- C K Chan
- NOCERAL, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Petaling Jaya, Malaysia
| | - Razif-Ma Mohamed
- NOCERAL, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Petaling Jaya, Malaysia
| | - A A Azlina
- NOCERAL, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Petaling Jaya, Malaysia
| | - M M Azhar
- NOCERAL, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Petaling Jaya, Malaysia
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Hui AT, Lam YO, Chan CK, Cheung KY, Fung BH, Ng PW. A case of refractory seizure with cognitive impairment due to anti-GABA encephalitis. Hong Kong Med J 2016; 22:509-11. [PMID: 27738301 DOI: 10.12809/hkmj154604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- A Th Hui
- Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
| | - Y O Lam
- Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
| | - C K Chan
- Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
| | - K Y Cheung
- Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
| | - B H Fung
- Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
| | - P W Ng
- Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
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Abstract
INTRODUCTION Mushroom poisoning is a cause of major mortality and morbidity all over the world. Although Hong Kong people consume a lot of mushrooms, there are only a few clinical studies and reviews of local mushroom poisoning. This study aimed to review the clinical characteristics, source, and outcome of mushroom poisoning incidences in Hong Kong. METHODS This descriptive case series review was conducted by the Hong Kong Poison Information Centre and involved all cases of mushroom poisoning reported to the Centre from 1 July 2005 to 30 June 2015. RESULTS Overall, 67 cases of mushroom poisoning were reported. Of these, 60 (90%) cases presented with gastrointestinal symptoms of vomiting, diarrhoea, and abdominal pain. Gastrointestinal symptoms were early onset (<6 hours post-ingestion) and not severe in 53 patients and all recovered after symptomatic treatment and a short duration of hospital care. Gastrointestinal symptoms, however, were of late onset (≥6 hours post-ingestion) in seven patients; these were life-threatening cases of amatoxin poisoning. In all cases, the poisonous mushroom had been picked from the wild. Three cases were imported from other countries, and four collected and consumed the amatoxin-containing mushrooms in Hong Kong. Of the seven cases of amatoxin poisoning, six were critically ill, of whom one died and two required liver transplantation. There was one confirmed case of hallucinogenic mushroom poisoning caused by Tylopilus nigerrimus after consumption of a commercial mushroom product. A number of poisoning incidences involved the consumption of wild-harvested dried porcini purchased in the market. CONCLUSION Most cases of mushroom poisoning in Hong Kong presented with gastrointestinal symptoms and followed a benign course. Life-threatening cases of amatoxin poisoning are occasionally seen. Doctors should consider this diagnosis in patients who present with gastrointestinal symptoms that begin 6 hours or more after mushroom consumption.
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Affiliation(s)
- C K Chan
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
| | - H C Lam
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
| | - S W Chiu
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - M L Tse
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
| | - F L Lau
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
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Chen Y, Phang WM, Mu AKW, Chan CK, Low BS, Sasidharan S, Chan KL. Decreased expression of alpha-2-HS glycoprotein in the sera of rats treated with Eurycoma longifolia extract. Front Pharmacol 2015; 6:211. [PMID: 26441666 PMCID: PMC4585282 DOI: 10.3389/fphar.2015.00211] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Accepted: 09/10/2015] [Indexed: 11/25/2022] Open
Abstract
Eurycoma longifolia is a Malaysian native herb that has been widely used as an aphrodisiac and a remedy for andropause. Although the physiological effects of the plant extract were predicted as a result of the alterations in protein expression, the key protein(s) involved in these alterations are still unclear. In the present study, we have investigated the effect of standardized E. longifolia extract on serum protein expression up to 28 days following oral administration in rats. Serum protein profiles were analyzed by 2-dimensional electrophoresis, and altered proteins were identified via mass spectrometry. We observed that alpha-2-HS glycoprotein (AHS) was significantly decreased in the serum of experimentally treated rats compared to pre-treated animals. Moreover, reduction in AHS was confirmed using competitive enzyme-linked immunosorbent assay. AHS expression is known to be associated with insulin resistance and diabetes. Our data indicated that serum AHS was reduced in rats treated with standardized E. longifolia extract, and therefore form a prelude for further investigation into the effects of this natural extract in animal models involving infertility and diabetes.
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Affiliation(s)
- Yeng Chen
- Department of Oral Biology and Biomedical Sciences, Faculty of Dentistry, University of Malaya Kuala Lumpur, Malaysia ; Oral Cancer Research and Coordinating Centre, Faculty of Dentistry, University of Malaya Kuala Lumpur, Malaysia
| | - Wai-Mei Phang
- Department of Oral Biology and Biomedical Sciences, Faculty of Dentistry, University of Malaya Kuala Lumpur, Malaysia
| | - Alan K-W Mu
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia Selangor, Malaysia
| | - Choon-Keat Chan
- Malaysian Institute of Pharmaceuticals and Nutraceuticals, Ministry of Science, Technology and Innovation Pulau Pinang, Malaysia
| | - Bin-Seng Low
- School of Pharmaceutical Sciences, Universiti Sains Malaysia Pulau Pinang, Malaysia ; School of Medicine, Taylor's University Selangor, Malaysia
| | - Sreenivasan Sasidharan
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia Pulau Pinang, Malaysia
| | - Kit-Lam Chan
- School of Pharmaceutical Sciences, Universiti Sains Malaysia Pulau Pinang, Malaysia
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Cheung K, Ling ZH, Wang DW, Wang Y, Guo H, Lee B, Li YJ, Chan CK. Characterization and source identification of sub-micron particles at the HKUST Supersite in Hong Kong. Sci Total Environ 2015; 527-528:287-296. [PMID: 25965042 DOI: 10.1016/j.scitotenv.2015.04.087] [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] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Revised: 04/16/2015] [Accepted: 04/23/2015] [Indexed: 06/04/2023]
Abstract
Particle size distribution measurements were conducted continuously at a 30-second interval using the Fast Mobility Particle Sizer (FMPS) in August, September, November and December of 2011 at a coastal background site in Hong Kong. Concurrent measurements of CO, NOx, O3, SO2 and volatile organic compounds (VOCs) were used to determine the causes of high particle number concentration (PNC) events. In all sampling months, PNC were usually higher in the evening, likely resulting from the arrival of upwind air pollutants as wind direction changed in the late afternoon. On the more polluted days, the PNC were usually higher around noon, particularly in August, similar to the diurnal trend of O3. The mode diameter at noon was smaller than in other time periods in all sampling months, further highlighting the role of secondary formation at this urban background site. A prolonged period of pollution episode occurred in late August. High PNC resulted from the arrival of pollution laden air from the PRD region or super regions. In December, new particle formation followed by subsequent growth accounted for most of the polluted days. Overall, meteorology was the most important parameter affecting particle concentrations and formation at this Hong Kong background site.
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Affiliation(s)
- K Cheung
- Air Quality Studies, Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China
| | - Z H Ling
- Air Quality Studies, Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China; Department of Atmospheric Sciences, School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China
| | - D W Wang
- Air Quality Studies, Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China
| | - Y Wang
- Air Quality Studies, Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China
| | - H Guo
- Air Quality Studies, Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China.
| | - B Lee
- Division of Environment, Hong Kong University of Science and Technology, Hong Kong, China
| | - Y J Li
- Division of Environment, Hong Kong University of Science and Technology, Hong Kong, China
| | - C K Chan
- Division of Environment, Hong Kong University of Science and Technology, Hong Kong, China; Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Hong Kong, China.
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Yang YJ, Chen CC, Lai PY, Chan CK. Adaptive synchronization and anticipatory dynamical systems. Phys Rev E Stat Nonlin Soft Matter Phys 2015; 92:030701. [PMID: 26465411 DOI: 10.1103/physreve.92.030701] [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] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Indexed: 06/05/2023]
Abstract
Many biological systems can sense periodical variations in a stimulus input and produce well-timed, anticipatory responses after the input is removed. Such systems show memory effects for retaining timing information in the stimulus and cannot be understood from traditional synchronization consideration of passive oscillatory systems. To understand this anticipatory phenomena, we consider oscillators built from excitable systems with the addition of an adaptive dynamics. With such systems, well-timed post-stimulus responses similar to those from experiments can be obtained. Furthermore, a well-known model of working memory is shown to possess similar anticipatory dynamics when the adaptive mechanism is identified with synaptic facilitation. The last finding suggests that this type of oscillator can be common in neuronal systems with plasticity.
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Affiliation(s)
- Ying-Jen Yang
- Institute of Physics, Academia Sinica, Taipei, Taiwan 115, Republic of China
- Department of Physics, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Chun-Chung Chen
- Institute of Physics, Academia Sinica, Taipei, Taiwan 115, Republic of China
| | - Pik-Yin Lai
- Institute of Physics, Academia Sinica, Taipei, Taiwan 115, Republic of China
- Department of Physics and Center for Complex Systems, National Central University, Chungli, Taiwan 320, Republic of China
| | - C K Chan
- Institute of Physics, Academia Sinica, Taipei, Taiwan 115, Republic of China
- Department of Physics and Center for Complex Systems, National Central University, Chungli, Taiwan 320, Republic of China
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Chan STB, Chan CK, Tse ML. Paracetamol overdose in Hong Kong: is the 150-treatment line good enough to cover patients with paracetamol-induced liver injury? Hong Kong Med J 2015; 21:389-93. [PMID: 26234689 DOI: 10.12809/hkmj144481] [Citation(s) in RCA: 3] [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 evaluate the failure rate of the 150-treatment line for paracetamol overdose in Hong Kong, and the impact if the treatment threshold was lowered. SETTING Public hospitals, Hong Kong. PATIENTS All patients with acute paracetamol overdose reported to the Hong Kong Poison Information Centre from 1 January 2011 to 31 December 2013 were studied and analysed for the timed serum paracetamol concentration and their relationship to different treatment lines. Presence of significant liver injury following paracetamol overdose was documented. The potential financial burden of different treatment lines implemented locally was estimated. RESULTS Of 893 patients, 187 (20.9%) had serum paracetamol concentration above the 150-treatment line, 112 (12.5%) had serum paracetamol concentration between the 100- and 150-treatment lines, and 594 (66.5%) had serum paracetamol level below the 100-treatment line. Of the 25 (2.8%) patients who developed significant liver injury, two were between the 100- and 150-treatment lines, and the other two were below the 100-treatment line. The failure rate of the 150-treatment line was 0.45%. Lowering the treatment threshold to the 100-treatment line might lower the failure rate of the treatment nomogram to 0.22% but approximately 37 more patients per year would need to be treated. It would incur an additional annual cost of HK$189 131 (US$24 248), and an additional 1.83 anaphylactoid reactions per year. The number needed-to-treat to potentially reduce one significant liver injury is 112. CONCLUSIONS Lowering the treatment threshold of paracetamol overdose may reduce the treatment-line failure rate. Nonetheless such a decision must be balanced against the excess in treatment complications and health care resources.
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Affiliation(s)
- Simon T B Chan
- Department of Accident and Emergency, United Christian Hospital, Kwun Tong, Hong Kong
| | - C K Chan
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
| | - M L Tse
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
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Abstract
OBJECTIVE To examine the impact of immigrant populations on the epidemiology of tuberculosis in Hong Kong. DESIGN Longitudinal cohort study. SETTING Hong Kong. PARTICIPANTS Socio-demographic and disease characteristics of all tuberculosis notifications in 2006 were captured from the statutory tuberculosis registry and central tuberculosis reference laboratory. Using 2006 By-census population data, indirect sex- and age-standardised incidence ratios by place of birth were calculated. Treatment outcome at 12 months was ascertained from government tuberculosis programme record forms, and tuberculosis relapse was tracked through the notification registry and death registry up to 30 June 2013. RESULTS Moderately higher sex- and age-standardised incidence ratios were observed among various immigrant groups: 1.06 (Mainland China), 2.02 (India, Pakistan, Bangladesh), 1.59 (Philippines, Thailand, Indonesia, Nepal), and 3.11 (Vietnam). Recent Mainland migrants had a lower sex- and age-standardised incidence ratio (0.51 vs 1.09) than those who immigrated 7 years ago or earlier. Age younger than 65 years, birth in the Mainland or the above Asian countries, and previous treatment were independently associated with resistance to isoniazid and/or rifampicin. Older age, birth in the above Asian countries, non-permanent residents, previous history of treatment, and resistance to isoniazid and/or rifampicin were independently associated with poor treatment outcome (other than cure/treatment completion) at 1 year. Birth outside Hong Kong was an independent predictor of relapse following successful completion of treatment (adjusted hazard ratio=1.76; 95% confidence interval, 1.07-2.89; P=0.025). CONCLUSION Immigrants carry with them a higher tuberculosis incidence and/or drug resistance rate from their place of origin. The higher drug resistance rate, poorer treatment outcome, and excess relapse risk raise concern over secondary transmission of drug-resistant tuberculosis within the local community.
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Affiliation(s)
- C C Leung
- Tuberculosis and Chest Service, Department of Health, Wanchai Chest Clinic, 1/F, 99 Kennedy Road, Wanchai, Hong Kong
| | - C K Chan
- Tuberculosis and Chest Service, Department of Health, Wanchai Chest Clinic, 1/F, 99 Kennedy Road, Wanchai, Hong Kong
| | - K C Chang
- Tuberculosis and Chest Service, Department of Health, Wanchai Chest Clinic, 1/F, 99 Kennedy Road, Wanchai, Hong Kong
| | - W S Law
- Tuberculosis and Chest Service, Department of Health, Wanchai Chest Clinic, 1/F, 99 Kennedy Road, Wanchai, Hong Kong
| | - S N Lee
- Tuberculosis and Chest Service, Department of Health, Wanchai Chest Clinic, 1/F, 99 Kennedy Road, Wanchai, Hong Kong
| | - L B Tai
- Tuberculosis and Chest Service, Department of Health, Wanchai Chest Clinic, 1/F, 99 Kennedy Road, Wanchai, Hong Kong
| | - Eric C C Leung
- Tuberculosis and Chest Service, Department of Health, Wanchai Chest Clinic, 1/F, 99 Kennedy Road, Wanchai, Hong Kong
| | - C M Tam
- Tuberculosis and Chest Service, Department of Health, Wanchai Chest Clinic, 1/F, 99 Kennedy Road, Wanchai, Hong Kong
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Chan CK, Abraham P, Sarraf D, Nuthi ASD, Lin SG, McCannel CA. Earlier therapeutic effects associated with high dose (2.0 mg) Ranibizumab for treatment of vascularized pigment epithelial detachments in age-related macular degeneration. Eye (Lond) 2014; 29:80-7. [PMID: 25277305 DOI: 10.1038/eye.2014.233] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 08/21/2014] [Indexed: 11/09/2022] Open
Abstract
SUMMARY STATEMENT Intravitreal high dose (2 mg) ranibizumab may lead to quicker resolution of choroidal neovascularization (CNV) and associated retinal pigment epithelial detachment in eyes with exudative age-related macular degeneration, although it may possibly correlate with RPE tears in certain cases. PURPOSE This prospective study compared the outcomes of 0.5 vs 2.0 mg intravitreal ranibizumab injections (RI) for treating vascularized pigment epithelial detachment (vPED) due to age-related macular degeneration. METHODS Patients with vPED were randomized to receive 2.0 vs 0.5 mg RI monthly for 12 months or for 4 months and then repeated on a pro-re nata basis. Optical coherence tomography, fundus photography, and fluorescein and indocyanine-green angiography were obtained at baseline and subsequent specific intervals. Outcome measures were best-corrected standardized visual acuities, central 1-mm thickness, surface area (SA), greatest linear diameter (GLD), heights (PED and CNV), and amount of subretinal fluid (SRF) and cystoid macular edema (CME). RESULTS Both groups yielded reductions of the central 1-mm thickness, PED and CNV SA and PED height and GLD, SRF, and CME. Vision improvement and reduction in SRF and PED height occurred earlier for eyes receiving the 2.0 mg dose. Cataract progression was similar but RPE tears developed more often with the 2.0 mg dose. CONCLUSIONS There were similar visual and anatomical outcomes at the end of the study; however, the higher dose yielded more rapid reductions and more complete resolution of the PED, although there was possible increased tendency for an RPE tear with the higher dose.
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Affiliation(s)
- C K Chan
- 1] Southern California Desert Retina Consultants, Palm Desert, CA, USA [2] Loma Linda University, Department of Ophthalmology, Loma Linda, CA, USA
| | - P Abraham
- Black Hills Regional Eye Institute, Rapid City, SD, USA
| | - D Sarraf
- Retinal Disorders and Ophthalmic Genetics, Jules Stein Eye Institute, UCLA, Los Angeles, CA, USA
| | - A S D Nuthi
- Southern California Desert Retina Consultants, Palm Desert, CA, USA
| | - S G Lin
- Southern California Desert Retina Consultants, Palm Desert, CA, USA
| | - C A McCannel
- Retinal Disorders and Ophthalmic Genetics, Jules Stein Eye Institute, UCLA, Los Angeles, CA, USA
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Abstract
We describe a case of lead exposure after prolonged intake of ashes from burnt Chinese talismans. A 41-year-old woman presented with elevated blood lead level during screening for treatable causes of progressive weakness in her four limbs, clinically compatible with motor neuron disease. The source of lead exposure was confirmed to be Chinese talismans obtained from a religious practitioner in China. The patient was instructed to burn the Chinese talismans to ashes, and ingest the ashes dissolved in water, daily for about 1 month. Analysis of the Chinese talismans revealed a lead concentration of 17 342 µg/g (ppm).
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Affiliation(s)
- C K Chan
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
| | - C K Ching
- Hospital Authority Toxicology Reference Laboratory, Princess Margaret Hospital, Laichikok, Hong Kong
| | - F L Lau
- Hong Kong Poison Information Centre, United Christian Hospital, Kwun Tong, Hong Kong
| | - H K Lee
- Department of Clinical Pathology, Tuen Mun Hospital, Tuen Mun, Hong Kong
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Song H, Chen CC, Sun JJ, Lai PY, Chan CK. Reconstruction of network structures from repeating spike patterns in simulated bursting dynamics. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 90:012703. [PMID: 25122331 DOI: 10.1103/physreve.90.012703] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Indexed: 06/03/2023]
Abstract
Repeating patterns of spike sequences from a neuronal network have been proposed to be useful in the reconstruction of the network topology. Reverberations in a physiologically realistic model with various physical connection topologies (from random to scale free) have been simulated to study the effectiveness of the pattern-matching method in the reconstruction of network topology from network dynamics. Simulation results show that functional networks reconstructed from repeating spike patterns can be quite different from the original physical networks; even global properties, such as the degree distribution, cannot always be recovered. However, the pattern-matching method can be effective in identifying hubs in the network. Since the form of reverberations is quite different for networks with and without hubs, the form of reverberations together with the reconstruction by repeating spike patterns might provide a reliable method to detect hubs in neuronal cultures.
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Affiliation(s)
- Hao Song
- Institute of Physics, Academia Sinica, Nankang, Taipei, Taiwan 115, Republic of China
| | - Chun-Chung Chen
- Institute of Physics, Academia Sinica, Nankang, Taipei, Taiwan 115, Republic of China
| | - Jyh-Jang Sun
- Neuro-Electronics Research Flanders, Kapeldreef 75, 3001 Leuven, Belgium
| | - Pik-Yin Lai
- Institute of Physics, Academia Sinica, Nankang, Taipei, Taiwan 115, Republic of China and Department of Physics and Center for Complex Systems, National Central University, Chungli, Taiwan 320, Republic of China
| | - C K Chan
- Institute of Physics, Academia Sinica, Nankang, Taipei, Taiwan 115, Republic of China and Department of Physics and Center for Complex Systems, National Central University, Chungli, Taiwan 320, Republic of China
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Lo KY, Chan CK. Characteristics and outcomes of patients with percutaneous coronary intervention for unprotected left main coronary artery disease: a Hong Kong experience. Hong Kong Med J 2014; 20:187-93. [PMID: 24812198 DOI: 10.12809/hkmj134069] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the intermediate-term outcomes of patients with unprotected left main coronary artery stenosis who were treated with percutaneous coronary intervention in Hong Kong. DESIGN Historical cohort. SETTING A regional hospital in Hong Kong. PATIENTS Patients with unprotected left main coronary artery disease undergoing stenting with bare-metal stents or drug-eluting stents between January 2008 and September 2011. MAIN OUTCOME MEASURES Incidence of restenosis and major adverse cardiac and cerebrovascular events including cardiac death, non-fatal myocardial infarction, stroke, and target lesion revascularisation. RESULTS Of the 111 patients included in the study, 86 received drug-eluting stents and 25 received bare-metal stents. Procedural success was achieved in 98.2% of cases. Angiographic follow-up was available in 83.8% of cases and restenosis rate was significantly lower with drug-eluting stents than with bare-metal stents (14.0% vs 40.0%; P=0.004). After a mean clinical follow-up of 26.1 (standard deviation, 12.6) months, the incidences of cardiac death (5.8% vs 16.0%; P=0.191) and non-fatal myocardial infarction (3.5% vs 8.0%; P=0.262) were similar between drug-eluting stents and bare-metal stents. However, the risks of target lesion revascularisation (9.3% vs 32.0%; P=0.001) and major adverse cardiac and cerebrovascular events (19.8% vs 44.0%; P=0.004) were significantly lower with drug-eluting stents than with bare-metal stents. CONCLUSIONS Performing percutaneous coronary intervention for unprotected left main coronary artery disease was safe and feasible in selected patients with high procedural success rate. The incidence of major adverse cardiac and cerebrovascular events in patients receiving drug-eluting stents remains low after intermediate-term follow-up. Compared with bare-metal stents, drug-eluting stents were associated with a lower need for repeating revascularisation without increasing the risk of death or myocardial infarction in patients with unprotected left main coronary artery disease.
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Affiliation(s)
- K Y Lo
- Division of Cardiology, Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
| | - C K Chan
- Division of Cardiology, Department of Medicine and Geriatrics, United Christian Hospital, Kwun Tong, Hong Kong
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Chan CK, Yung SH, Liu MW, Chan KM. THE CHANGE IN LOWER LIMB KINEMATIC AND EMG ACTIVITY OF SPRINTING AFTER SOCCER-SPECIFIC FATIGUE AMONG FEMALE SOCCER PLAYERS. Br J Sports Med 2014. [DOI: 10.1136/bjsports-2014-093494.50] [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: 11/03/2022]
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Chan CK, Wong KH, Leung CC, Tam CM, Chan KCW, Pang KW, Chan WK, Mak IKY. Treatment outcomes after early initiation of antiretroviral therapy for human immunodeficiency virus-associated tuberculosis. Hong Kong Med J 2013; 19:474-83. [PMID: 23926173 DOI: 10.12809/hkmj133937] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To evaluate the optimal timing for initiating antiretroviral therapy in patients with human immunodeficiency virus (HIV)-associated tuberculosis in Hong Kong. DESIGN Historical cohort. SETTING. Tuberculosis and Chest Service and Special Preventive Programme, Public Health Service Branch, Centre for Health Protection, Department of Health, Hong Kong. PATIENTS Consecutive patients with HIV-associated tuberculosis in a territory-wide TB-HIV registry encountered from 1996 to 2009. RESULTS Of the 260 antiretroviral therapy-naïve patients with HIV-associated tuberculosis, 32 (12%) had antiretroviral therapy initiated within 2 months after starting anti-tuberculosis treatment (early antiretroviral therapy). Early antiretroviral therapy was associated with a more favourable outcome (cure or treatment completion without relapse) at 24 months (91% vs 67%; P=0.007) than those with antiretroviral therapy started later or not initiated, and remained an independent predictor of a favourable outcome after adjustment for potential confounders. Adverse effects from anti-tuberculosis drugs tended to occur more frequently in patients with early antiretroviral therapy (13/32 or 41%) compared with the remainder (59/228 or 26%; P=0.08). A significantly higher proportion of patients in the former group experienced immune reconstitution inflammatory syndrome than in the latter group (7/32 or 22% vs 9/228 or 4%; P<0.001). There was no death attributable to immune reconstitution inflammatory syndrome. CONCLUSIONS Early initiation of antiretroviral therapy is associated with more favourable tuberculosis treatment outcomes in patients with HIV-associated tuberculosis with a low CD4 count (<200/µL). Drug co-toxicity and immune reconstitution inflammatory syndrome that may be increased by earlier initiation of antiretroviral therapy does not undermine tuberculosis treatment outcomes to a significant extent.
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Affiliation(s)
- C K Chan
- Tuberculosis and Chest Service, Public Health Service Branch, Centre for Health Protection, Department of Health, Hong Kong
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Wang MX, Li YJ, Lai PY, Chan CK. Model on cell movement, growth, differentiation and de-differentiation: reaction-diffusion equation and wave propagation. Eur Phys J E Soft Matter 2013; 36:65. [PMID: 23807466 DOI: 10.1140/epje/i2013-13065-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 04/17/2013] [Accepted: 06/04/2013] [Indexed: 06/02/2023]
Abstract
We construct a model for cell proliferation with differentiation into different cell types, allowing backward de-differentiation and cell movement. With different cell types labeled by state variables, the model can be formulated in terms of the associated transition probabilities between various states. The cell population densities can be described by coupled reaction-diffusion partial differential equations, allowing steady wavefront propagation solutions. The wavefront profile is calculated analytically for the simple pure growth case (2-states), and analytic expressions for the steady wavefront propagating speeds and population growth rates are obtained for the simpler cases of 2-, 3- and 4-states systems. These analytic results are verified by direct numerical solutions of the reaction-diffusion PDEs. Furthermore, in the absence of de-differentiation, it is found that, as the mobility and/or self-proliferation rate of the down-lineage descendant cells become sufficiently large, the propagation dynamics can switch from a steady propagating wavefront to the interesting situation of propagation of a faster wavefront with a slower waveback. For the case of a non-vanishing de-differentiation probability, the cell growth rate and wavefront propagation speed are both enhanced, and the wavefront speeds can be obtained analytically and confirmed by numerical solution of the reaction-diffusion equations.
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Affiliation(s)
- Mao-Xiang Wang
- Department of Physics, Graduate Institute of Biophysics, and Center for Complex Systems, National Central University, Chungli, Taiwan, 320, ROC
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Sridhar S, Le DM, Mi YC, Sinha S, Lai PY, Chan CK. Suppression of cardiac alternans by alternating-period-feedback stimulations. Phys Rev E Stat Nonlin Soft Matter Phys 2013; 87:042712. [PMID: 23679454 DOI: 10.1103/physreve.87.042712] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/18/2013] [Indexed: 06/02/2023]
Abstract
Alternans response, comprising a sequence of alternating long and short action potential durations in heart tissue, seen during rapid periodic pacing can lead to conduction block resulting in potentially fatal cardiac failure. A method of pacing with feedback control is proposed to reduce the alternans and therefore the probability of subsequent cardiac failure. The reduction is achieved by feedback control using small perturbations of constant magnitude to the original, alternans-generating pacing period T, viz., using sequences of two alternating periods of T+ΔT and T-ΔT, with ΔT<<T. Such a control scheme for alternans suppression is demonstrated experimentally in isolated whole heart experiments. This alternans suppression scheme is further confirmed and investigated in detail by simulations of ion-channel-based cardiac models both for a single cell and in one-dimensional spatially extended systems. The mechanism of the success of our method can be understood in terms of dynamics in phase space, viz., as the state of activity of the cell being confined within a narrow volume of phase space for the duration of control, resulting in extremely diminished variation in successive action potential durations. Our method is much more robust to noise than previous alternans reduction techniques based on fixed point stabilization and should thus be more efficient in terms of experimental implementation, which has implications for clinical treatment for arrhythmia.
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Affiliation(s)
- S Sridhar
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
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