PubMed Health⌕ Search

Biomedical subjects

C M Leung

Publications and source records attributed to C M Leung.

At least 37 records · Page 2Linked to original sources

Huntington's disease in Hong Kong Chinese: epidemiology and clinical picture.

In a territory-wide survey of Huntington's disease (HD) in the Chinese population of Hong Kong, 20 patients from 11 families were identified from 1984 to 1991, giving a low period prevalence of 3.7 per 10(6) population. Six patients had died by 1991, hence the point prevalence was even lower, being 2.5 per 10(6) population. The male to female ratio was 3:1. No paternal transmission effect on the age of onset was observed. Apart from these differences, the clinical and pathological features were similar to those seen in the West.

Adult↗

Reliability, validity and structure of the Chinese Geriatric Depression Scale in a Hong Kong context: a preliminary report.

Depression is one of the commonest psychiatric illness in the elderly. Screening instruments of depression can greatly facilitate its identification in the community, leading to early recognition and diagnosis. The Geriatric Depression Scale was translated into Chinese and its reliability, validity and factor structure examined in a population of Chinese elderly in Hong Kong. One hundred and thirteen normal and 80 depressed elderly subjects were studied and a cut-off score of 15 on the scale was found to be optimal. The scale's reliability and validity was satisfactory and thus it is a promising instrument for screening geriatric depression in Hong Kong.

Aged↗

Prevalence of tardive dyskinesia in samples of elderly people in Hong Kong.

The prevalence of dyskinesia was studied in 4 samples of elderly Chinese people in Hong Kong--a psychogeriatric clinic, a mental hospital, a geriatric day hospital and a senior citizen centre. Research Diagnostic Criteria were used to identify cases of tardive dyskinesia. The overall prevalence of spontaneous dyskinesia was 2.4% and tardive dyskinesia was 25.9%. The rate of spontaneous dyskinesia differs across the study samples and is related to nervous system conditions associated with increased age. On the other hand, the rate of dyskinesia associated with antidepressants may not be significantly different from that of spontaneous dyskinesia.

Aged↗

Evaluation of the Chinese version of the Hospital Anxiety and Depression Scale. A cross-cultural perspective.

The authenticity of the Chinese translation of the Hospital Anxiety and Depression Scale (HAD) was tested in a sample of medical students. The Chinese version demonstrated good agreement with the English original. There was a large difference between the mean anxiety and depression subscores. Factor analysis consistently yielded three factors, suggesting the existence of a somatic factor. It is suggested that a common cut-off point for the subscales of the HAD scale is not advisable and a multidimensional model for mood disorders is more appropriate in a cross-cultural context.

Adult↗

Psychiatric morbidity in a general medical ward. Hong Kong's experience.

The psychiatric morbidity of a general hospital's male medical ward in Hong Kong was studied using a one-stage single-rater method. Medical diagnoses were made according to ICD-9 on 91.5% of patients and 24% were diagnosed with DSM-III. The most common mental disorders included substance use disorder, dementia, and delirium. Of all the patients, 8.5% were not medically diagnosable and 5.3% were given only psychiatric diagnoses, the majority of which were substance use disorders.

Adolescent↗

Huntington's disease in Chinese: a hypothesis of its origin.

The period prevalence (1984-91) of Huntington's disease (HD) in Hong Kong Chinese was 3.7 per million population. HD patients in Mainland China and Hong Kong showed similar hereditary pattern, clinical and pathological features as in the West. Chinese HD patients were male predominant with a younger age of onset and death. Their ancestral origin could be traced mostly to the coastal provinces of China. It is proposed that Chinese HD patients may have a European origin and share the same gene pool as their white counterparts.

China↗

Epidemiology and management of respiratory burns in National Burns Centre, Singapore.

Respiratory burns constitute one of the two leading causes of burns mortality today, the other being infection. When cutaneous burns are complicated by co-existent respiratory or inhalational injury, the mortality remains high in most reported series. We began our prospective study of respiratory burns in 1982 as a multi-disciplinary team effort involving respiratory physicians, anaesthetists and our burns physicians. Between 1982 until February 1990, we treated a total of 240 patients with respiratory burns. During the same period, a total of 4041 patients were admitted to our Burns Centre at Singapore General Hospital. Respiratory burns cases therefore constituted 5.4% of the total burns admissions. In our series, there were 44 deaths out of 240 patients, giving an overall mortality of 18.3%. The average size of burns in the patients who died was 57.4% BSA in Group A patients, 65.0% BSA in Group B and 57.7% BSA in Group C. Our management protocol has gradually evolved over the eight years of the study. Systemic antibiotics and steroids are no longer used routinely. Fiberoptic bronchoscopy is done early in the ward as a bedside procedure once a patient is clinically assessed to have suffered a respiratory burns and repeat bronchoscopic examination done when deemed necessary. An aggressive regime of respiratory support measures with early intubation and PEEP ventilation is recommended.

Adolescent↗

Morbidity and mortality in respiratory burns--a prospective study of 240 cases.

A prospective study of 240 consecutive admissions with respiratory burns over an eight-year period beginning 1982 was carried out at the National Burns Centre, Singapore General Hospital. Diagnosis of respiratory burns was based on clinical criteria and a clinical score was then computed to grade the severity. Investigations included chest x-rays, blood gases, carboxyhaemoglobin level, lung scan and fibreoptic bronchoscopy. Treatment was carried out according to a standard protocol where a policy of early intervention in the form of endotracheal intubation was emphasised. Other respiratory support measures were chest physiotherapy, tracheobronchial suction, mucolytics and bronchoscopic lavage where indicated. We found that respiratory burns was a significant cause of mortality in burns patients. The influence on mortality was most marked in patients with large body surface area burns of more than 40%. Age was also an important determinant of survival with patients older than 50 years faring significantly worse. The routine steroids and prophylactic antibiotics did not influence the survival rate. Carbon monoxide poisoning was not a significant cause of mortality. We achieved an overall mortality rate of 18.3%, with 44 deaths out of 240 patients. The main causes of deaths at post-mortem were bronchopneumonia, septicaemia and extensive burns.

Adolescent↗

Mass ammonia inhalational burns--experience in the management of 12 patients.

Twelve Korean crew members of a deep sea fishing vessel were admitted to the Burns Centre, Singapore General Hospital following exposure to ammonia gas. The injuries sustained were primarily respiratory burns with minor cutaneous and corneal burns. They were divided into three grades of severity based on the admission findings and subsequent clinical course. Management was according to a standard respiratory burns protocol. Eight patients were intubated. Ten of the patients with mild and moderate involvement of the respiratory tract recovered without complication. Of the two patients with severe respiratory burns, one died while another progressed to chronic debilitating airway disease.

Accidents, Occupational↗

Neuroleptic prescription for Chinese schizophrenics in Hong Kong.

There are very few studies on the pattern of neuroleptic prescription for schizophrenics in Asia. 106 schizophrenic patients in a psychiatric unit of a general teaching hospital in Hong Kong were surveyed. The mean daily dose (in chlorpromazine equivalent) was low (568.5mg). The mean daily dose of high potency agents was four times that of low potency agents. A high frequency of use of anticholinergic drugs may indicate that Chinese are more susceptible to acute extrapyramidal side-effects.

Adult↗

Acne as a risk factor for anorexia nervosa in Chinese.

Acne is a highly visible and common skin disorder which is potentially disfiguring and associated with adverse emotional responses in adolescents, who are markedly sensitive to body image changes. Two psychologically vulnerable Chinese girls are reported, in whom traditional health concepts reinforced dieting behaviour, led to weight loss, regression of acne and eventually anorexia nervosa. The intricate interactions of acne, health beliefs, dieting behaviour and eating disorders are discussed.

Achievement↗

Changes in preganglionic sympathetic nerve function following chronic morphine treatment in rats.

1. The effects of acute or chronic morphine treatment on the changes in blood pressure and pulse rate in response to ganglionic stimulation or blockade and to vagal stimulation, and of isolated atria to field stimulation or noradrenaline, were studied. 2. In pithed rats, intravenously injected hexamethonium significantly depressed the blood pressure responses to sympathetic nerve stimulation. The ganglionic blocking effects of hexamethonium were significantly greater in chronically morphine-treated rats, but were not significantly affected by acute morphine administration in naive animals. 3. Intravenous administration of nicotine dose-dependently increased blood pressure and pulse rate. The magnitudes of these changes were not significantly affected by acute or chronic morphine pretreatment. 4. Studies with rat isolated atrial preparations revealed that the changes in atrial contractile rate and force in response to noradrenaline or field stimulation were not influenced by either acute or chronic morphine treatment. 5. Cervical vagal stimulation produced voltage- or frequency-dependent decreases in pulse rate and blood pressure. The responses were not significantly affected by chronic morphine treatment. 6. These findings suggest that the site of the changes in sympathetic function following prolonged exposure to the opiate appears to be on the preganglionic nerve fibres.

Animals↗

Risk factors of suicide among schizophrenics.

This case control study included 74 Chinese schizophrenics (DSM-III criteria) who died of suicide and 74 age- and sex-matched nonsuicide schizophrenics. Sociodemographic variables were unrelated with suicide. Associations were found between suicide and severity of illness (more frequent admissions, higher dose of medication and earlier appointments), history of major depressive episodes and suicidal attempts, last admission for reasons other than schizophrenic symptoms alone, and suicidal ideas on mental state examination. The last 2 factors, together with the maintenance dose of medication, were identified as the most important risk factors by logistic regression analysis.

Adult↗

Arterial catecholamine levels in morphine-treated rats subjected to sympathetic nerve stimulation.

1. The effect of acute or chronic morphine treatment on the changes in arterial noradrenaline and adrenaline levels in response to sympathetic nerve stimulation was studied in rats. 2. Rats which had been chronically treated with morphine in their drinking fluid for 21 days were shown to be morphine-tolerant, as revealed by the tail-immersion test for analgesia. 3. It was found that animals given either acute or chronic morphine treatment had similar basal concentrations of arterial catecholamines to their controls. 4. Sympathetic nerve stimulation produced significant increases in arterial noradrenaline and adrenaline levels in both the control and morphine-treated animals. However, the degree of arterial noradrenaline elevation was significantly less in morphine-tolerant animals. 5. This phenomenon was not observed in acutely morphine-treated rats or at 2 weeks following opiate withdrawal in animals which had been treated previously with morphine for 3 weeks. 6. The findings suggest that chronic morphine treatment in rats not only leads to opiate tolerance but also reduces catecholamine release in response to sympathetic nerve stimulation.

Animals↗

Suicide among Chinese schizophrenics in Hong Kong.

A descriptive study of suicides in 74 Chinese schizophrenic out-patients (43 male) is presented. The mean age at death was 31.3 years. The mean duration of illness was 8.5 years and 50 of the 74 died within ten years of onset of illness. Only five lived alone; 35 were openly employed and 20 were married at the time of death. Twenty had a history of depression, and 27 had attempted suicide previously. More females had been depressed or had attempted suicide than males. Over half were last admitted for reasons other than schizophrenic symptoms alone and ten died within one month of discharge. Eight of 71 patients followed up expressed suicidal ideas at the last psychiatric contact, but only 15 were symptomatic. Jumping was the commonest method used. Analytical studies are needed to identify risk factors in Chinese schizophrenics.

Adult↗

Cardiovascular responses to sympathetic nerve stimulation in morphine-treated rats.

The effects of morphine on the responses of blood pressure and pulse rate to stimulation of sympathetic nerves or to intravenous administration of noradrenaline were studied in female rats which had been treated with either an increasing concentration of morphine sulphate in their drinking fluid (5% sucrose solution), or an acute intraperitoneal injection of morphine. Sympathetic nerve excitation was effected by electrical stimulation of the thoracic segments of the spinal cord in pithed rats. Both sympathetic nerve stimulation and noradrenaline produced dose-dependent changes in blood pressure and pulse rate in naive rats and in the sucrose-drinking controls. Animals which had been chronically treated with morphine in their drinking fluid for 21 days showed significantly less intense responses to sympathetic nerve stimulation. However, these decreased responses were not observed in rats given acute treatment with morphine. Chronic treatment with morphine did not significantly influence the changes in blood pressure or pulse rate induced by noradrenaline. These findings suggest that chronic treatment with morphine lessens the cardiovascular responses to stimulation of peripheral sympathetic nerves in rats. The mechanism is not clear, but it seems unlikely to be due to changes in the sensitivity, or perhaps the number, of adrenoceptors.

Animals↗