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1.
J Vitreoretin Dis ; 4(2): 157-162, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-37008379

RESUMEN

Purpose: This report describes the development of focal choroidal excavation (FCE) and recurrent central serous chorioretinopathy (CSCR) following the treatment of choroidal neovascularization (CNV) years earlier. Methods: A case report is presented. Results: A 30-year-old man previously treated for an active CNV returned several years later with subacute metamorphopsia. Optical coherence tomography and angiography demonstrated no recurrence of the CNV but instead found an FCE and associated CSCR in its place. Conclusion: Longitudinal follow-up with multimodal imaging demonstrated FCE with recurrent CSCR as possible sequelae of treated CNV.

2.
Bioinspir Biomim ; 12(2): 026008, 2017 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-28084219

RESUMEN

The growth of leading-edge vortices (LEV) on analogous flapping and rotating profiles has been investigated experimentally. Three time-varying cases were considered: a two-dimensional reference case with a spanwise-uniform angle-of-attack variation α; a case with increasing α towards the profile tip (similar to flapping flyers); and a case with increasing α towards the profile root (similar to rotor blades experiencing an axial gust). It has been shown that the time-varying spanwise angle-of-attack gradient produces a vorticity gradient, which, in combination with spanwise flow, results in a redistribution of circulation along the profile. Specifically, when replicating the angle-of-attack gradient characteristic of a rotor experiencing an axial gust, the spanwise-vorticity gradient is aligned such that circulation increases within the measurement domain. This in turn increases the local LEV growth rate, which is suggestive of force augmentation on the blade. Reversing the relative alignment of the spanwise-vorticity gradient and spanwise flow, thereby replicating that arrangement found in a flapping flyer, was found to reduce local circulation. From this, we can conclude that spanwise flow can be arranged to vary LEV growth to prolong lift augmentation and reduce the unsteadiness of cyclic loads.


Asunto(s)
Aviación/instrumentación , Materiales Biomiméticos , Vuelo Animal/fisiología , Robótica , Rotación , Alas de Animales/fisiología , Aceleración , Animales , Fenómenos Biomecánicos , Modelos Biológicos
3.
Epidemiol Infect ; 144(6): 1248-56, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26538070

RESUMEN

Hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) is becoming increasingly established in Asian hospitals. The primary aim of this study was to decompose the risk factors for HA-MRSA based on conceptual clinical pathways. The secondary aim was to show the amount of effect attributable to antibiotic exposure and total length of stay before outcome (LBO) so that institutions can manage at-risk patients accordingly. A case-control study consisting of 1200 inpatients was conducted in a large tertiary hospital in Singapore between January and December 2006. Results from the generalized structural equation model (GSEM) show that LBO [adjusted odds ratio (aOR) 14·9, 95% confidence interval (CI) 8·7-25·5], prior hospitalization (aOR 6·2, 95% CI 3·3-11·5), and cumulative antibiotic exposure (aOR 3·5, 95% CI 2·3-5·3), directly affected HA-MRSA acquisition. LBO accounted for the majority of the effects due to age (100%), immunosuppression (67%), and surgery (96%), and to a lesser extent for male gender (22%). Our model enabled us to account and quantify effects of intermediaries. LBO was found to be an important mediator of age, immunosuppression and surgery on MRSA infection. Traditional regression approaches will not only give different conclusions but also underestimate the effects. Hospitals should minimize the hospital stay when possible to reduce the risk of MRSA.


Asunto(s)
Infección Hospitalaria/epidemiología , Tiempo de Internación , Staphylococcus aureus Resistente a Meticilina/fisiología , Infecciones Estafilocócicas/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Infección Hospitalaria/microbiología , Femenino , Humanos , Masculino , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Persona de Mediana Edad , Factores de Riesgo , Singapur/epidemiología , Infecciones Estafilocócicas/microbiología
4.
Med Teach ; 32(3): e120-6, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20218827

RESUMEN

BACKGROUND: Many doctors experience psychological ill health. Interns are known to be particularly vulnerable. AIM: To examine the level of depression, anxiety and stress in interns in Hong Kong, as well as the causes and how they cope. METHODS: A questionnaire was designed based on the themes identified in three focus groups of medical graduates of Year 2004 of the University of Hong Kong. The 21-item Depression, Anxiety and Stress Scale (DASS 21) was also administered. All 155 graduates of the same year were invited to participate with a response rate of 63%. RESULTS: Percentages of respondents with abnormal levels of depression, anxiety and stress were 35.8%, 35.4% and 29.2%, respectively. Frequent calls during night shift, long working hours and heavy workload constituted the most significant stressors. Factor analysis of the stressors showed that seven factors could explain 68% of the total variance: multidisciplinary team working issues, clinical difficulties, job seeking and employment, workload issues, ethical and interpersonal issues, adjustment to job rotation and performance appraisal. Holidays, peers and sleep offered the most significant relief. CONCLUSION: Interns experience considerable depression, anxiety and stress. The source of stress is multi-faceted, but workload is the most significant stressor. Peer support groups may relief stress.


Asunto(s)
Adaptación Psicológica , Ansiedad/epidemiología , Depresión/epidemiología , Internado y Residencia/estadística & datos numéricos , Estrés Psicológico/complicaciones , Adulto , Ansiedad/etiología , Recolección de Datos , Depresión/etiología , Femenino , Grupos Focales , Hong Kong/epidemiología , Humanos , Masculino , Psicometría , Investigación Cualitativa , Encuestas y Cuestionarios , Tolerancia al Trabajo Programado , Carga de Trabajo , Adulto Joven
5.
East Asian Arch Psychiatry ; 20(4): 155-62, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22348923

RESUMEN

OBJECTIVES: To explore the preparedness of medical students towards advance directives and related end-of-life issues, and to examine background factors such as knowledge, attitudes, and experience concerning advance directives and related end-of-life issues. METHODS: In 2007, 448 medical students in years 3 to 5 were surveyed at the Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong. Their knowledge, attitudes, and experiences of advance directives and related end-of-life issues, and their self-perceived preparedness to discuss these matters with patients were evaluated. RESULTS: A total of 220 (49%) of the eligible students responded, of whom 79% supported the use of advance directives. Only 65 (30%) students were certain of what advance directives meant and 198 (90%) students felt that their knowledge of advance directives was inadequate. Also, 197 (90%) students felt unprepared about advance directives and end-of-life issues. Factors associated with positive attitude towards advance directives included religion and knowledge. No factors were found to be associated with self-perceived preparedness towards advance directives or end-of-life issues. CONCLUSIONS: Most of the medical students surveyed demonstrated a positive attitude towards advance directives and recognised the importance of advance directives. However, they felt that they were unprepared and lacking in knowledge and experience of advance directives and end-of-life issues. Wider range and more depth of education is needed to better equip medical students for future practice.

6.
Psychol Med ; 38(6): 877-85, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17949516

RESUMEN

BACKGROUND: Diffusion tensor imaging (DTI) can be used to investigate cerebral structural connectivity in never-medicated individuals with first-episode schizophrenia. METHOD: Subjects with first-episode schizophrenia according to DSM-IV-R who had never been exposed to antipsychotic medication (n=25) and healthy controls (n=26) were recruited. Groups were matched for age, gender, best parental socio-economic status and ethnicity. All subjects underwent DTI and structural magnetic resonance imaging (MRI) scans. Voxel-based analysis was performed to investigate brain regions where fractional anisotropy (FA) values differed significantly between groups. A confirmatory region-of-interest (ROI) analysis of FA scores was performed in which regions were placed blind to group membership. RESULTS: In patients, FA values significantly lower than those in healthy controls were located in the left fronto-occipital fasciculus, left inferior longitudinal fasciculus, white matter adjacent to right precuneus, splenium of corpus callosum, right posterior limb of internal capsule, white matter adjacent to right substantia nigra, and left cerebral peduncle. ROI analysis of the corpus callosum confirmed that the patient group had significantly lower mean FA values than the controls in the splenium but not in the genu. The intra-class correlation coefficient (ICC) for independent ROI measurements was 0.90 (genu) and 0.90 (splenium). There were no regions where FA values were significantly higher in the patients than in the healthy controls. CONCLUSIONS: Widespread structural dysconnectivity, including the subcortical region, is already present in neuroleptic-naive patients in their first episode of illness.


Asunto(s)
Encéfalo/fisiopatología , Imagen de Difusión por Resonancia Magnética , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Red Nerviosa/fisiopatología , Esquizofrenia/fisiopatología , Psicología del Esquizofrénico , Adulto , Anisotropía , Encéfalo/patología , Dominancia Cerebral/fisiología , Femenino , Humanos , Masculino , Red Nerviosa/patología , Escalas de Valoración Psiquiátrica , Esquizofrenia/diagnóstico
7.
Med Teach ; 29(9): 984-6, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18158678

RESUMEN

BACKGROUND: Psychological morbidity is commonly found in medical students. AIMS: The Mental Health Support Group (MSG), a student-initiated and student-run web-based peer support service aims to provide mental health information, e mail counseling and an online forum for medical students. METHODS: The development process of MSG is described in the paper with presentation of preliminary evaluation results. RESULTS: Preliminary evaluation shows promising results. Student members of MSG acquired valuable skills in counseling, communication, webpage design and maintenance of an online forum. CONCLUSIONS: Future challenges include succession issues, strategies to keep up the momentum, enhancement of publicity and further diversification of service to meet the needs of our students.


Asunto(s)
Información de Salud al Consumidor/métodos , Promoción de la Salud/métodos , Salud Mental , Estudiantes de Medicina/psicología , Información de Salud al Consumidor/tendencias , Femenino , Hong Kong , Humanos , Internet , Masculino , Trastornos Mentales/psicología , Grupo Paritario , Evaluación de Programas y Proyectos de Salud , Factores Sexuales , Apoyo Social , Estrés Psicológico/psicología , Encuestas y Cuestionarios
8.
J Med Ethics ; 31(5): 262-5, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15863680

RESUMEN

The practice of covertly administering medication is controversial. Although condemned by some as overly paternalistic, others have suggested that it may be acceptable if patients have permanent mental incapacity and refuse needed treatment. Ethical, legal, and clinical considerations become more complex when the mental incapacity is temporary and when the medication actually serves to restore autonomy. We discuss these issues in the context of a young man with schizophrenia. His mother had been giving him antipsychotic medication covertly in his soup. Should the doctor continue to provide a prescription, thus allowing this to continue? We discuss this case based on the "four principles" ethical framework, addressing the conflict between autonomy and beneficence/non-maleficence, the role of antipsychotics as an autonomy restoring agent, truth telling and the balance between individual versus family autonomy.


Asunto(s)
Antipsicóticos/administración & dosificación , Ética Médica , Alimentos , Esquizofrenia/tratamiento farmacológico , Administración Oral , Adulto , Beneficencia , Cuidadores , Humanos , Masculino , Competencia Mental , Paternalismo , Autonomía Personal , Relaciones Médico-Paciente
9.
Med Teach ; 27(8): 715-9, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16451893

RESUMEN

There has been much recent attention on psychological well-being and pastoral care for medical students. This study examines psychological morbidity (depression, anxiety and stress) in Hong Kong medical students, as well as their concerns, coping mechanisms and their help-seeking. Medical students in Hong Kong reported a higher level of psychological morbidity as compared with other tertiary education students. Their main concerns include examinations, stress, career, adjusting to the new medical curriculum and commitment to the course. The coping skills adopted were largely adaptive. Maladaptive coping skills like 'denial', 'self-blame' and 'behavioural disengagement' were highly correlated with depression, anxiety and stress scores. Most of the students concerned wanted support services that were specifically tailored to their needs and at least partly provided by people who had been through medical training themselves. The faculty at the University of Hong Kong is establishing a Programme for Effective Transition and Student Support (PETSS) to provide a multi-faceted support system for its medical students. The findings in this study help to ensure that the services provided will be relevant, accessible and acceptable to the students.


Asunto(s)
Satisfacción Personal , Estudiantes de Medicina/psicología , Adaptación Psicológica , Adolescente , Adulto , Estudios Transversales , Femenino , Hong Kong , Humanos , Masculino , Cuidado Pastoral
10.
Hong Kong Med J ; 9(4): 284-9, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12904617

RESUMEN

A person's decision-making capacity is pivotal when a doctor determines whether a person has the ability to make his or her own decisions, and thus it has major clinical, ethical, and legal significance, especially in Hong Kong, where the Mental Health Ordinance has introduced Guardianship provisions and provisions for the treatment of mentally incapacitated persons. This paper examines the legal concept of decision-making capacity and its clinical assessment within the local context. It is important for doctors to be aware of the legal mechanisms under which both urgent and non-urgent treatment can be given to mentally incapacitated persons, provided that the treatment is necessary and given in the best interests of the patient.


Asunto(s)
Consentimiento Informado/legislación & jurisprudencia , Competencia Mental/legislación & jurisprudencia , Salud Mental , Evaluación de Necesidades , Adulto , Anciano , Algoritmos , Toma de Decisiones , Femenino , Hong Kong , Humanos , Consentimiento Informado/psicología , Tutores Legales/legislación & jurisprudencia , Masculino , Competencia Mental/psicología , Persona de Mediana Edad , Guías de Práctica Clínica como Asunto , Negativa del Paciente al Tratamiento/legislación & jurisprudencia , Negativa del Paciente al Tratamiento/psicología
11.
J Med Ethics ; 27(6): 393-7, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11731603

RESUMEN

With advances in genetic technology, there are increasing concerns about the way in which genetic information may be abused, particularly in people at increased genetic risk of developing certain disorders. In a recent case in Hong Kong, the court ruled that it was unlawful for the civil service to discriminate in employment, for the sake of public safety, against people with a family history of mental illness. The plaintiffs showed no signs of any mental health problems and no genetic testing was performed. This was the first case concerning genetic discrimination in common law jurisdictions, therefore the court's judgment has implications for how genetic discrimination cases may be considered in the future. The court considered it inappropriate to apply population statistics or lifetime risks to individuals while examining fitness for work. It recommended an individualised assessment of specific risks within the job, relative to other risks posed by that workplace.


Asunto(s)
Personas con Discapacidad/legislación & jurisprudencia , Empleo/legislación & jurisprudencia , Prejuicio , Esquizofrenia/genética , Adulto , Hong Kong , Humanos , Solicitud de Empleo , Perfil Laboral , Masculino , Medición de Riesgo , Lugar de Trabajo/legislación & jurisprudencia
13.
Clin Exp Ophthalmol ; 29(3): 188-92, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11446466

RESUMEN

Animal models, in vitro assays and pilot clinical studies suggest that intravitreal triamcinolone acetonide may be useful in the treatment of age-related macular degeneration. The present case study reports the effect of intravitreal triamcinolone acetonide injection on a subretinal neovascular lesion, microglial morphology and quantitative expression of MHC-II antigens. Triamcinolone acetonide significantly decreased MHC-II expression consistent with immunocytochemical observations which revealed condensed microglial morphology. The modulation of subretinal oedema and microglial morphology correlates with in vitro observations suggesting that downregulation of inflammatory markers and endothelial cell permeability are significant features of the mode of action of triamcinolone acetonide.


Asunto(s)
Neovascularización Coroidal/tratamiento farmacológico , Glucocorticoides/uso terapéutico , Antígenos HLA-DR/metabolismo , Degeneración Macular/tratamiento farmacológico , Microglía/patología , Triamcinolona Acetonida/uso terapéutico , Anciano , Anciano de 80 o más Años , Neovascularización Coroidal/metabolismo , Neovascularización Coroidal/patología , Regulación hacia Abajo , Femenino , Angiografía con Fluoresceína , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Inmunohistoquímica , Inyecciones , Degeneración Macular/metabolismo , Degeneración Macular/patología , Microglía/metabolismo , Microscopía Confocal , Cuerpo Vítreo
15.
J Exp Biol ; 204(Pt 3): 575-83, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11171308

RESUMEN

Previous studies have shown that, during search flight in bats, wingbeat, respiration and echolocation are synchronised in a 1:1 relationship. An efficiently integrated locomotor-respiratory system enables bats to produce intense echolocation signals at little or no cost above that required for flight. In this study, we investigated the coupling of wingbeat with echolocation in the laboratory during approach flight in soprano pipistrelles (Pipistrellus pygmaeus) using high-speed digital video at 250 and 500 frames s(-)(1). We found that soprano pipistrelles most commonly produce single or double pulses per wingbeat. Single pulses per wingbeat occurred in two alternative positions: immediately before the end of the upstroke or after the start of the downstroke. Double pulses per wingbeat were emitted in the same wingbeat positions on the upstroke and the downstroke, as in single pulses per wingbeat. We suggest that, during approach flight, the coupling of more than one echolocation signal with a single wingbeat and expiratory cycle allows echolocation to remain energetically economic. When soprano pipistrelles approached a Perspex disc target, an increase in mean repetition rate was achieved by producing an extra pulse per wingbeat. Finally, we hypothesise that the bat's approach to potentially interesting targets in the same horizontal plane as it's flight path, i.e. during flapping flight, may be characterised by the production of double pulses per wingbeat, resulting in a unique pattern of echolocation pulse intervals.


Asunto(s)
Conducta Animal/fisiología , Quirópteros/fisiología , Ecolocación/fisiología , Animales
16.
Psychol Med ; 30(2): 295-306, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10824650

RESUMEN

BACKGROUND: Based on the developing clinical and legal literature, and using the framework adopted in draft legislation, capacity to make a valid decision about a clinically required blood test was investigated in three groups of people with a 'mental disability' (i.e. mental illness (chronic schizophrenia), 'learning disability' ('mental retardation', or intellectual or developmental disability), or, dementia) and a fourth, comparison group. METHODS: The three 'mental disability' groups (N = 20 in the 'learning disability' group, N = 21 in each of the other two groups) were recruited through the relevant local clinical services; and through a phlebotomy clinic for the 'general population' comparison group (N = 20). The decision-making task was progressively simplified by presenting the relevant information as separate elements and modifying the assessment of capacity so that responding became gradually less dependent on expressive verbal ability. RESULTS: Compared with the 'general population' group, capacity to make the particular decision was significantly more impaired in the 'learning disability' and 'dementia' groups. Importantly, however, it was not more impaired among the 'mental illness' group. All the groups benefited as the decision-making task was simplified, but at different stages. In each of the 'mental disability' groups, one participant benefited only when responding did not require any expensive verbal ability. CONCLUSIONS: Consistent with current views, capacity reflected an interaction between the decision-maker and the demands of the decision-making task. The findings have implications for the way in which decisions about health care interventions are sought from people with a 'mental disability'. The methodology may be extended to assess capacity to make other legally-significant decisions.


Asunto(s)
Consentimiento Informado/legislación & jurisprudencia , Competencia Mental/legislación & jurisprudencia , Personas con Discapacidades Mentales/legislación & jurisprudencia , Adolescente , Adulto , Recolección de Muestras de Sangre , Demencia/diagnóstico , Demencia/psicología , Inglaterra , Humanos , Discapacidad Intelectual/diagnóstico , Discapacidad Intelectual/psicología , Persona de Mediana Edad , Personas con Discapacidades Mentales/psicología , Esquizofrenia/diagnóstico , Psicología del Esquizofrénico
20.
Postgrad Med ; 106(4): 21, 1999 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-10533502
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