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So HY, Li PKT, Lai PBS, Chan ACL, Chan KKL, Chan TM, Chao DVK, Chiu SN, Chu KM, Ho KY, Lam HSHS, Law CK, Law SW, Ngai CM, Pang FC, Tham CCY, Wu CWY, Leung GKK. Hong Kong Academy of Medicine position paper on postgraduate medical education 2023. Hong Kong Med J 2023; 29:448-452. [PMID: 37710982 DOI: 10.12809/hkmj2310942] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2023] Open
Affiliation(s)
- H Y So
- Educationist, Hong Kong Academy of Medicine / President, The Hong Kong College of Anaesthesiologists, Hong Kong SAR, China
| | - P K T Li
- Vice-President (Education and Examinations), Hong Kong Academy of Medicine, Hong Kong SAR, China
| | - P B S Lai
- Immediate Past Vice-President (Education and Examinations), Hong Kong Academy of Medicine, Hong Kong SAR, China
| | - A C L Chan
- President, The Hong Kong College of Pathologists, Hong Kong SAR, China
| | - K K L Chan
- President, The Hong Kong College of Obstetricians and Gynaecologists, Hong Kong SAR, China
| | - T M Chan
- President, Hong Kong College of Physicians, Hong Kong SAR, China
| | - D V K Chao
- President, The Hong Kong College of Family Physicians, Hong Kong SAR, China
| | - S N Chiu
- President, The Hong Kong College of Psychiatrists, Hong Kong SAR, China
| | - K M Chu
- President, The College of Surgeons of Hong Kong, Hong Kong SAR, China
| | - K Y Ho
- President, The College of Dental Surgeons of Hong Kong, Hong Kong SAR, China
| | - H S H S Lam
- President, Hong Kong College of Paediatricians, Hong Kong SAR, China
| | - C K Law
- President, Hong Kong College of Radiologists, Hong Kong SAR, China
| | - S W Law
- President, The Hong Kong College of Orthopaedic Surgeons, Hong Kong SAR, China
| | - C M Ngai
- President, The Hong Kong College of Otorhinolaryngologists, Hong Kong SAR, China
| | - F C Pang
- President, Hong Kong College of Community Medicine, Hong Kong SAR, China
| | - C C Y Tham
- Immediate Past President, The College of Ophthalmologists of Hong Kong, Hong Kong SAR, China
| | - C W Y Wu
- President, Hong Kong College of Emergency Medicine, Hong Kong SAR, China
| | - G K K Leung
- President, Hong Kong Academy of Medicine, Hong Kong SAR, China
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Vaishnav M, Javed A, Gupta S, Kumar V, Vaishnav P, Kumar A, Salih H, levounis P, NG B, Alkhoori S, Luguercho C, Soghoyan A, Moore E, Lakra V, Aigner M, Wancata J, Ismayilova J, Islam MA, Da Silva AG, Chaimowitz G, Xiaoping W, Okasha T, Meyer-Lindenberg A, Schulze T, NG R, Chiu SN, (Sherry) CKW, Tanra AJ, Park YC, Panteleeva L, Taveras M, Mazaliauskiene R, Sulaiman AHB, Sanchez T, Sedain CP, Sheikh TL, Lien L, Rasool G, Buenaventura R, Gambheera HC, Ranasinghe K, Sartorius N, Charnsil C, Larnaout A, Nakku J, Ashurov Z. Stigma towards mental illness in Asian nations and low-and-middle-income countries, and comparison with high-income countries: A literature review and practice implications. Indian J Psychiatry 2023; 65:995-1011. [PMID: 38108051 PMCID: PMC10725213 DOI: 10.4103/indianjpsychiatry.indianjpsychiatry_667_23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [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: 08/31/2023] [Revised: 09/23/2023] [Accepted: 09/23/2023] [Indexed: 12/19/2023] Open
Abstract
Background Stigma related to mental illness (and its treatment) is prevalent worldwide. This stigma could be at the structural or organizational level, societal level (interpersonal stigma), and the individual level (internalized stigma). Vulnerable populations, for example, gender minorities, children, adolescents, and geriatric populations, are more prone to stigma. The magnitude of stigma and its negative influence is determined by socio-cultural factors and macro (mental health policies, programs) or micro-level factors (societal views, health sectors, or individuals' attitudes towards mentally ill persons). Mental health stigma is associated with more serious psychological problems among the victims, reduced access to mental health care, poor adherence to treatment, and unfavorable outcomes. Although various nationwide and well-established anti-stigma interventions/campaigns exist in high-income countries (HICs) with favorable outcomes, a comprehensive synthesis of literature from the Low- and Middle-Income Countries (LMICs), more so from the Asian continent is lacking. The lack of such literature impedes growth in stigma-related research, including developing anti-stigma interventions. Aim To synthesize the available mental health stigma literature from Asia and LMICs and compare them on the mental health stigma, anti-stigma interventions, and the effectiveness of such interventions from HICs. Materials and Methods PubMed and Google Scholar databases were screened using the following search terms: stigma, prejudice, discrimination, stereotype, perceived stigma, associate stigma (for Stigma), mental health, mental illness, mental disorder psychiatric* (for mental health), and low-and-middle-income countries, LMICs, High-income countries, and Asia, South Asian Association for Regional Cooperation/SAARC (for countries of interest). Bibliographic and grey literature were also performed to obtain the relevant records. Results The anti-stigma interventions in Asia nations and LMICs are generalized (vs. disorder specific), population-based (vs. specific groups, such as patients, caregivers, and health professionals), mostly educative (vs. contact-based or attitude and behavioral-based programs), and lacking in long-term effectiveness data. Government, international/national bodies, professional organizations, and mental health professionals can play a crucial in addressing mental health stigma. Conclusion There is a need for a multi-modal intervention and multi-sectoral coordination to mitigate the mental health stigma. Greater research (nationwide surveys, cultural determinants of stigma, culture-specific anti-stigma interventions) in this area is required.
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Affiliation(s)
- Mrugesh Vaishnav
- Samvedana Group of Hospital and Research Centre, Institute of Psychological and Sexual Research-Samvedana Foundation, Ahmedabad, Gujarat, India
| | - Afzal Javed
- World Psychiatric Association (WPA), Geneva, Switzerland
| | - Snehil Gupta
- Associate Professor, Dept. of Psychiatry, All India Institute of Medical Sciences (AIIMS), Bhopal, Madhya Pradesh, India
| | - Vinay Kumar
- President, Indian Psychiatric Society, Ahmedabad, Gujarat, India
| | | | - Akash Kumar
- Department of Psychiatry, All India Institute of Medical Sciences (AIIMS), Bhopal, India
| | - Hakimullah Salih
- President, Afghanistan National Psychiatrists Association, San Diego, USA
| | | | - Bernardo NG
- Clinical Assistant Professor, Department of Psychiatry, University of California, San Diego, USA
| | - Samia Alkhoori
- Department of Psychiatry, School of Clinical Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | - Cora Luguercho
- President, Association of Argentine Psychiatrists (APSA), Australia
| | | | - Elizabeth Moore
- President of the Royal Australian and New Zealand College of Psychiatrists (RANZCP), Australia
| | - Vinay Lakra
- Divisional Director, Mental Health, Northern Health, Australia
| | - Martin Aigner
- President, Austrian Society for Psychiatry, Psychotherapy and Psychosomatics
| | - Johannes Wancata
- Professor and Chair for Social Psychiatry, Medical University of Vienna, University Campus
| | - Jamila Ismayilova
- The National Mental Health Center of the Ministry of Health of Azerbaijan
| | - Md. Azizul Islam
- President, Bangladesh Association of Psychiatrist, Principal, US-Bangla Medical College
| | | | - Gary Chaimowitz
- Head of Service, Forensic Psychiatry Program, St. Joseph's Healthcare, Hamilton
| | | | - Tarek Okasha
- Professor of Psychiatry, Okasha Institute of Psychiatry, Faculty of Medicine Ain Shams University in Cairo, Egypt
| | | | - Thomas Schulze
- Director of the Institute of Psychiatric Phenomics and Genomics (www.ippg.eu) at the University Hospital of LMU, Munich, Germany
| | | | - SN Chiu
- President, Hong Kong College of Psychiatrists
| | - Chan Kit Wa (Sherry)
- Department of Psychiatry, School of Clinical Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR
| | | | - Yong Chon Park
- Emeritus Professor, Department of Psychiatry, Han Yang University, Seoul, Korea
| | | | - Marisol Taveras
- Department of Mental Health, Dr. Ney Arias Lora Traumatology Hospital, Santo Domingo Norte
| | - Ramune Mazaliauskiene
- Lithuanian Health Sciences University; Lithuanian Health Sciences University Kaunas Hospital
| | | | | | | | | | - Lars Lien
- Department of Health and Social Science, Innlandet University of Applied Science, Elverum, Norway
| | | | - Robert Buenaventura
- Associate Professor II, La Consolacion University Philippines College of Medicine
| | | | | | - Norman Sartorius
- President, Association for the Improvement of Mental Health Programmes (AMH), Geneva, Switzerland
| | - Chawanun Charnsil
- Professor of Psychiatry: Department of Psychiatry, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Amine Larnaout
- Razi Hospital, Faculty of Medicine of Tunis, Tunis El Manar University, Tunisia
| | - Juliet Nakku
- Butabika Hospital and Makerere University, Kampala, Uganda
| | - Zarif Ashurov
- Head of the Psychiatry and Narcology, Department of the Tashkent Medical Academy
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Hsu CY, Wu MH, Chiu SN, Lin MT, Lai LP, Chen WJ, Lin TT, Juang JM. Investigate clinical characteristics and genetic mutations of CPVT patients in Taiwan and risk stratification. Europace 2021. [DOI: 10.1093/europace/euab116.332] [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
Funding Acknowledgements
Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology
Background
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare and lethal arrhythmia in children and young adults. RYR2 mutation accounts for 60% of CPVT patients. While many articles about CPVT are published in the Caucasian population, only a few studies are based on Asian ethnicity. A CPVT scorecard proposed using Caucasian patients is proven effective in reducing the burden of variants of uncertain significance (VUS) of RYR2 mutations is not yet tested in the Asian population.
Purpose
Identify mutations among Taiwanese CPVT patients and compare genetic and clinical results with other ethnicities. We also tested the efficacy of the CPVT scorecard in Taiwanese CPVT patients.
Methods
40 clinically diagnosed CPVT patients and their family members were consecutively enrolled from multi-centers. We compared clinical characteristics and genetic results with other ethnicities, and applied the Caucasian CPVT scorecard to test whether it is applicable in Taiwanese CPVT patients.
Results
This is the first nationwide CPVT cohort in Taiwan. Among the 29 patients with CPVT-related gene mutation, 12 RYR2 variants was identified in our cohort with 5 of them unreported in previous studies. The RYR2 yield rate was 55%, similar to other ethnicities. Exercise-induced symptoms including syncope and cardiac arrest were more severe in Taiwanese CPVT cohort, compared to Japanese and Caucasian cohorts. The CPVT scorecard also successfully reduced the VUS rate for the Taiwanese cohort.
Conclusions
Our study demonstrated genetic difference in CPVT patients across ethnicities, suggesting the importance of genetic testing in Taiwan. The CPVT scorecard is applicable to Taiwanese CPVT patients and is a helpful tool in interpreting genetic test results in clinical practice. Clinical characteristics of the cohort Gender (male, %) 15 (52%) Mean age of onset (years) 18 ± 15 Exercise-related syncope or cardiac arrest (n, %) 23 (79%) Exercise-related cardiac arrest (n, %) 14 (48%) Family history of unexplained sudden cardiac death (n, %) 5 (17%) Heart rate (bpm) 73 ± 16 Exercise stress test or Holter positive (n, %) 14 (48%) Ventricular arrhythmia (n, %) 23 (79%) Beta-blockers only (n, %) 10 (35%) Intracardiac defibrillator implantation (n, %) 15 (52%) CPVT score 6 ± 3
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Affiliation(s)
- CY Hsu
- National Taiwan University, College of Medicine, Taipei, Taiwan
| | - MH Wu
- National Taiwan University Hospital, Taipei, Taiwan
| | - SN Chiu
- National Taiwan University Hospital, Taipei, Taiwan
| | - MT Lin
- National Taiwan University Hospital, Taipei, Taiwan
| | - LP Lai
- National Taiwan University Hospital, Taipei, Taiwan
| | - WJ Chen
- National Taiwan University Hospital, Taipei, Taiwan
| | - TT Lin
- National Taiwan University, College of Medicine, Taipei, Taiwan
| | - JM Juang
- National Taiwan University, College of Medicine, Taipei, Taiwan
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Abstract
The DNA of higher animals replicates by an interesting mechanism. Enzymes recognise specific sites randomly scattered on the molecule and establish a bidirectional process of unwinding and replication from these sites. We investigate the limiting distribution of the completion time for this process by considering related coverage problems investigated by Janson (1983) and Hall (1988).
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Abstract
The double-stranded molecule, DNA, has the unique property of replication and, because of this, it is the central molecule of life. The mechanism of replication for each single strand is intricate, involving enzymes which move along each of the single strands building a complementary copy. At the frontier of this action, the events have a strong stochastic character due to the random location on the DNA of key ‘sites' where copying commences. A model of this process is analysed. The central problem of interest is the mean length of certain ‘islands' of newly replicated DNA developed at the randomly located ‘sites'. These islands, which have been observed experimentally, are called Okazaki fragments.
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Abstract
Is the intersection between an arbitrary but fixed plane and the spatial Poisson Voronoi tessellation a planar Voronoi tessellation? In this paper a negative answer is given to this long-standing question in stochastic geometry. The answer remains negative for the intersection between at-dimensional linear affine space and thed-dimensional Poisson Voronoi tesssellation, where 2 ≦t≦d− 1. Moreover, it is shown that each cell on this intersection is almost surely a non-Voronoi cell.
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Abstract
Seeds are randomly scattered in ℝd according to an m-dependent point process. Each seed has its own potential germination time. From each seed that succeeds in germinating, a spherical inhibited region grows to prohibit germination of any seed with later potential germination time. We show that under certain conditions on the distribution of the potential germination time, the number of germinated seeds in a large region has an asymptotic normal distribution.
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Abstract
Johnson–Mehl tessellations can be considered as the results of spatial birth–growth processes. It is interesting to know when such a birth–growth process is completed within a bounded region. This paper deals with the limiting distributions of the time of completion for various models of Johnson–Mehl tessellations in ℝd and k-dimensional sectional tessellations, where 1 ≦ k < d, by considering asymptotic coverage probabilities of the corresponding Boolean models. Random fractals as the results of birth–growth processes are also discussed in order to show that a birth–growth process does not necessarily lead to a Johnson–Mehl tessellation.
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Cowan R, Chiu SN. Extension of Deltheil's study on random points in a convex quadrilateral. ADV APPL PROBAB 2016. [DOI: 10.1239/aap/1127483751] [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: 11/18/2022]
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Abstract
The mean number of edges of a randomly chosen neighbouring cell of the typical cell in a planar stationary tessellation, under the condition that it has n edges, has been studied by physicists for more than 20 years. Experiments and simulation studies led empirically to the so-called Aboav's law. This law now plays a central role in Rivier's (1993) maximum entropy theory of statistical crystallography. Using Mecke's (1980) Palm method, an exact form of Aboav's law is derived. Results in higher-dimensional cases are also discussed.
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Abstract
This paper introduces a new graph constructed from a point process. The idea is to connect a point with its nearest neighbour, then to the second nearest and continue this process until the point belongs to the interior of the convex hull of these nearest neighbours. The number of such neighbours is called the degree of a point. We derive the distribution of the degree of the typical point in a Poisson process, prove a central limit theorem for the sum of degrees, and propose an edge-corrected estimator of the distribution of the degree that is unbiased for a stationary Poisson process. Simulation studies show that this degree is a useful concept that allows the separation of clustering and repulsive behaviour of point processes.
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Abstract
Consider the following birth-growth model in ℝ. Seeds are born randomly according to an inhomogeneous space-time Poisson process. A newly formed point immediately initiates a bi-directional coverage by sending out a growing branch. Each frontier of a branch moves at a constant speed until it meets an opposing one. New seeds continue to form on the uncovered parts on the line. We are interested in the time until a bounded interval is completely covered. The exact and limiting distributions as the length of interval tends to infinity are obtained for this completion time by considering a related Markov process. Moreover, some strong limit results are also established.
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Zhang SP, Chiu TTW, Chiu SN. Long-term efficacy of electroacupuncture for chronic neck pain: a randomised controlled trial. Hong Kong Med J 2013; 19 Suppl 9:36-39. [PMID: 24473589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
Electroacupuncture is a safe treatment for chronic neck pain. Nonetheless, one month after treatment, improvement of neck pain is similar to that in placebo-treated controls. This suggests that the efficacy may not be due to specific effect of the treatment procedure.
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Affiliation(s)
- S P Zhang
- School of Chinese Medicine, Hong Kong Baptist University
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Chiu SN, Molchanov IS, Quine MP. Maximum likelihood estimation for germination-growth processes with application to neurotransmitters data. J STAT COMPUT SIM 2003. [DOI: 10.1080/0094965031000078855] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Lee KYS, van Hasselt CA, Chiu SN, Cheung DMC. Cantonese tone perception ability of cochlear implant children in comparison with normal-hearing children. Int J Pediatr Otorhinolaryngol 2002; 63:137-47. [PMID: 11955605 DOI: 10.1016/s0165-5876(02)00005-8] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND OBJECTIVE Cantonese is a tone language. A change in the fundamental frequency pattern within the same phonemic segment causes a change in the lexical meaning. The present study examined the Cantonese tone perception ability of cochlear implant children in comparison with normal-hearing children. It was hypothesized that cochlear implant children follow a similar pattern of tone perception development, as do normal children. METHOD 225 normal-hearing and 15 hearing-impaired children with cochlear implants were recruited. The high level (tone 1), high rising (tone 2) and low falling (tone 4) were the target tones examined. The three tones were arranged into tone pairs for identification. Each pair shared exactly the same segmental information but differed only in tones (e.g. /sy/ in tones 1 and 2 meaning 'book' and 'mouse', respectively). Subjects were required to point to the corresponding pictures after the live voice presentations. RESULTS for each tone pair, each subject was awarded a score representing the proportion of stimuli pairs that were correctly discriminated by the subject. The average scores in the normal-hearing and hearing-impaired groups were 0.92 and 0.64, respectively. The normal group had the lowest average score in tone 2/tone 4 (0.87) while the hearing-impaired group performed the worst in tone 1/tone 2 (0.53) perception between the three tone contrasts. CONCLUSIONS the normal-hearing group performed significantly better than the hearing-impaired group in basic Cantonese tone perception. The pattern of tone perception development of cochlear implant children did not seem to follow that of normal children. Contributing factors on the tone perception performance of the cochlear implant children were subject's age, duration of special training, and durations of wearing the hearing aid and the cochlear implant.
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Affiliation(s)
- Kathy Y S Lee
- Division of Otorhinolaryngology, Department of Surgery, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.
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Affiliation(s)
- S. N. Chiu
- Department of Mathematics, Hong Kong Baptist University, Kowloon Tong, Hong Kong,
| | - D. Stoyan
- TU Bergakademie Freiberg, Institut für Stochastik, D‐09596 Freiberg, Germany
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Chiu SN, Wu MH, Wang JK, Lin JH, Chen YS, Hsu RB, Jou NK, Lue HC, Chu SH. Heart transplantation and the Batista operation for children with refractory heart failure. Jpn Circ J 2001; 65:289-93. [PMID: 11316125 DOI: 10.1253/jcj.65.289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Medically refractory heart failure may be present in children with cardiomyopathy (CMP) or complex congenital heart disease (CHD). In adults, the surgical management of this condition is either heart transplantation or the Batista operation. From March 1995 to January 2000, a total of 6 children, aged from 1 to 16 years, with medically refractory heart failure associated with CMP or complex CHD underwent cardiac transplantation and one of them also had the Batista operation as a bridge to transplantation. One of the 6 patients died of intractable sepsis 17 days after the operation, but the other 5 were discharged with satisfactory hemodynamics. Immunosuppressive agents, including azathioprine, cyclosporin or FK-506, were given. One patient experienced moderate acute rejection, but it was controlled by FK-506, OKT-3 and solumedrol. However, another suffered from lymphoproliferative disease 8 months after transplant, but it was controlled by intravenous immunoglubulin, alpha-interferon and acyclovir. Cardiac function during serial follow-up (range, 1 month to 5 years) revealed normal systolic and diastolic function and none received any anticongestive medications. Almost all patients received an oversized donor heart. The left ventricle (LV) mass was remodeled, initially as an decrease and later as an increase. The patient who underwent the Batista operation was discharged 1 month after the operation with an increased LV ejection fraction (from 10% to 22%). She was successfully bridged to heart transplantation 7 months after the Batista operation. The results of cardiac transplantation in growing children are satisfactory and remain the mainstay of surgical treatment for medically refractory heart failure in these patients. However, with a shortage of donor hearts, the Batista operation may be adopted as a bridge to heart transplant with a fair response.
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Affiliation(s)
- S N Chiu
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Republic of China
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Molchanov IS, Chiu SN, Zuyev SA. Design of inhomogeneous materials with given structural properties. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 2000; 62:4544-4552. [PMID: 11088993 DOI: 10.1103/physreve.62.4544] [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] [Subscribe] [Scholar Register] [Received: 05/05/2000] [Indexed: 05/23/2023]
Abstract
We describe a technique applicable to optimize certain quantities associated with the two-phase structure described by a model of penetrable grains. The solution is given in a form of an intensity surface that controls locations of the grains. Particular examples include maximization of the expected phase 2 volume and design of functionally graded materials with a given density profile.
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Affiliation(s)
- IS Molchanov
- Department of Statistics, University of Glasgow, Glasgow G12 8QW, United Kingdom
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Abstract
Seeds are planted on the interval [0, L] at various locations. Each seed has a location x and a potential germination time t epsilon [0, infinity), and it is assumed that the collection of such (x, t) pairs forms a Poisson process in [0, L] x [0, infinity) with intensity measure dxd lambda(t). From each seed that germinates, an inhibiting region grows bidirectionally at rate 2v. These regions inhibit germination of any seed in the region with a later potential germination time. Thus, seeds only germinate in the uninhibited part of [0, L]. We want to estimate lambda on the basis of one or more realizations of the process, the data being the locations and germination times of the germinated seeds. We derive the maximum likelihood estimator of v and a nonparametric estimator of lambda and describe methods of obtaining parametric estimates from it, illustrating these with reference to gamma densities. Simulation results are described and the methods applied to some neurobiological data. An Appendix outlines the S-PLUS code used.
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Affiliation(s)
- S N Chiu
- Department of Mathematics, Hong Kong Baptist University, Kowloon, Hong Kong.
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Ungvari GS, Chiu HF, Lam LC, Pang AH, Chung DW, Li SW, Chiu SN, Lum FC, Leung T. Gradual withdrawal of long-term anticholinergic antiparkinson medication in Chinese patients with chronic schizophrenia. J Clin Psychopharmacol 1999; 19:141-8. [PMID: 10211915 DOI: 10.1097/00004714-199904000-00009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Previous antiparkinson drug withdrawal studies involving white subjects have yielded inconclusive findings, whereas there is a paucity of data concerning Asian patients. A double-blind, placebo-controlled, randomized trial using gradual withdrawal of antiparkinson medication was conducted to evaluate the need for maintenance antiparkinson therapy for clinically stable Chinese patients with chronic schizophrenia. Seventy-five schizophrenic subjects who had received a diagnosis according to DSM-IV who had been ill for at least 5 years and on antipsychotic and antiparkinson medication for a minimum of 2 years entered the study. After baseline assessment, 58 subjects were matched according to age, sex, age at onset, length of illness, dose and length of antipsychotic and antiparkinson medication, and the presence of various extrapyramidal side effects. Randomly assigned dose-reduction and control groups were formed consisting of 29 subjects each. Trihexyphenidyl (THP), the only oral antiparkinson drug used in the study, was reduced by 1 mg every 2 weeks, whereas other psychotropic medication remained unchanged. Monthly assessment was performed using the Brief Psychiatric Rating Scale, Hamilton Rating Scale for Depression, Abnormal Involuntary Movement Scale, Simpson-Angus Scale, Barnes Akathisia Rating Scale, and the Nursing Observation Scale for Inpatient Evaluation-30. Complete withdrawal of THP was possible in 25 (90%) of the 28 subjects who completed the study, whereas considerable dose reduction was achieved in the remaining 3 subjects. There were no significant differences between dose reduction and control groups on any of the rating scales at the completion of the study. Our results suggest that long-term prophylactic administration of antiparkinson medication is unnecessary in the treatment of the majority of Chinese patients with chronic schizophrenia because withdrawal was accomplished without adverse mental or motor effects.
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Affiliation(s)
- G S Ungvari
- Department of Psychiatry, Chinese University of Hong Kong, Hong Kong SAR.
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Chiu SN, Quine MP. Central limit theory for the number of seeds in a growth model in $\bold R\sp d$ with inhomogeneous Poisson arrivals. ANN APPL PROBAB 1997. [DOI: 10.1214/aoap/1034801254] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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