PubMed HealthSearch

Biomedical subjects

T H Lam

Publications and source records attributed to T H Lam.

At least 19 recordsLinked to original sources

Pickled vegetables in the aetiology of oesophageal cancer in Hong Kong Chinese.

Oesophageal cancer is common in Chinese populations, but individual-based epidemiological studies have provided little explanation. A case control study with 400 cases and 1598 controls (800 hospital and 798 general practice) was conducted among Hong Kong Chinese. In multivariate analyses, statistically significant effects on risk were detected for several potentially preventable exposures with high attributable risks (ARs). These included preference for consuming drinks or soups at high temperature (AR = 14%), infrequent consumption of green leafy vegetables (AR = 15%) and citrus fruits (AR = 26%), ingestion of pickled vegetables (AR = 29%), tobacco smoking (AR = 44%), and alcohol drinking (AR = 48%). On the assumption of multiplicative risk, the combined AR due to these exposures was 89%. This is the first case control study to show an association between pickled vegetable consumption and oesophageal cancer risk. The finding considerably strengthens the evidence for carcinogenicity of N-nitroso compounds in man and helps to explain the very high risk among Chinese.

Aged

Dysbaric osteonecrosis in a compressed air tunnelling project in Hong Kong.

In the largest compressed air tunnelling project using the Blackpool Decompression Tables in Hong Kong, 912 men had radiological examination of major joints and 12 definite and 30 suspected cases of dysbaric osteonecrosis were detected by the compressed air physician. Distribution of the lesions was symmetrical and 43.1 per cent were juxta-articular. All the cases were asymptomatic. The infrequent occurrence of osteonecrosis in Hong Kong in general and in this project in particular suggests that the Blackpool Tables were relatively effective in preventing the disease. Definite and suspected cases were pooled together for the study of risk factors for osteonecrosis. Logistic regression analysis showed that the number of bends ever experienced, number of hours worked in the present contract, age and obesity were important independent risk factors. Because of the impossibility of a suitably long follow-up for all workers, the prevalence of osteonecrosis may be under-reported in Hong Kong.

Adult

Studies on the respiratory health of primary school children in urban communities of Hong Kong.

The first stage of a 2-year survey of respiratory morbidity in primary school children was conducted in two districts of Hong Kong in April/May 1989. One group (2009) of children was from Kwai Tsing District, which had high levels of exhaust emission from factories. The other group (1837) was from Southern District where atmospheric pollution was considered to be relatively low. After adjustment for gender, age, socioeconomic factors, child smoking and exposure to parental smoking, the prevalence ratios of sore throat, evening cough, cough for more than 3 months, morning phlegm and wheezing were found to be significantly higher in Kwai Tsing. The difference between the districts is likely to be related to the environmental air quality. The study, which is continuing, will provide the basis for an evaluation of the impact of new low sulphur fuel regulations introduced in July 1990.

Acute Disease

Contact dermatitis due to topical treatment with garlic in Hong Kong.

Contact dermatitis due to garlic is usually due to handling of garlic for cooking. Among the Chinese, garlic is also used as a form of topical medicament. 8 patients developed contact dermatitis after rubbing the cut end of a fresh garlic bulb onto the skin to treat fungal and other infections at the groin, neck, lower limb, hand or face. The distribution and morphology of the lesions were different from the classical form as described in the literature. Repeated open application tests with fresh garlic were all positive and patch tests with garlic extract were all negative. 5 controls tested by repeated open application with fresh garlic juice were also positive and patch tests in 10 controls with garlic extract were also negative. The results confirmed that the contact dermatitis was due to irritation. The patients were treated successfully with topical fluorinated steroid. For prevention, the practice of direct application of fresh garlic onto the skin for treating infections should be discouraged.

Administration, Cutaneous

Smoking among young doctors in Hong Kong: a message to medical educators.

A survey was conducted using a self-administered questionnaire to examine the smoking habits, attitudes and practices of 151 doctors in their pre-registration year. The response rate was 88%. Over 80% of the respondents had never smoked. Less than 7% of the men smoked daily and none of the women smoked. Despite a very low smoking rate among the respondents, there were shortcomings in attitudes and practices. The study demonstrated that even in a place like Hong Kong, where the social climate on smoking is already changing in a healthy direction, significant deficiencies in our graduates can still arise if teaching on smoking and its control is undertaken in an uncoordinated manner. We argue that a specific course on the important aspects of smoking and health should be introduced into all undergraduate curricula. This is of special importance in countries where smoking is one the increase and where governmental actions on smoking control are inadequate in comparison with the marketing efforts of powerful multinational tobacco companies. Considering the magnitude of smoking as a global health problem, it is the very least that medical educators should do in combating this pandemic.

Adult

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

Patch testing of 11 common herbal topical medicaments in Hong Kong.

11 common herbal topical medicaments in Hong Kong were selected for patch testing to study whether they could cause skin reactions under occlusive conditions. These included White Flower Oil, Hung Far Oil, Kwan Loong Medicated Oil, Tiger Oil, Jaminton Oil, Bee Brand Oil, Tiger Balm, Au Kah Chuen Skin Lotions, Mopiko Ointment, OronineH Ointment and Mentholatum. The former 7 were traditional Chinese herbal medicaments, the last one was made in USA and the remaining 2 were Japanese products. 20 patients were patch tested with the 11 medicaments. Hung Far Oil caused mild to moderately severe irritation in 8 patients; White Flower Oil, Jaminton Oil and Tiger Balm caused mild irritation in 1 to 3 patients; and the rest showed no positive reactions at all. With the exception of Hung Far Oil, all the other medicaments should be safe when applied openly. For Hung Far Oil, additional warning as to its irritant properties and the proper method for its application should be provided for the protection of its users.

Administration, Cutaneous

Patch testing in Hong Kong.

The acceptability and value of patch testing in Hong Kong was studied in 56 cases of suspected dermatitis (CD), 26 cases of endogenous eczema (EE) and 30 cases of unclassified eczema (UE), selected systematically: all those suspected of having CD and 1 in 3 of the others. 81.3% of the 112 patients selected accepted the test. The main reasons for refusal were inconvenience and lack of time for the readings. Of the 91 tested, in 88 they were successfully completed. In 39 patients, the results were negative, while 49 patients reacted to 1 or more allergens. The 2 commonest sensitizers were fragrance-mix (15 patients) and nickel sulphate (14 patients). The "usefulness" of patch testing was defined as it causing the initial clinical diagnosis to be changed. The test was found to be "useful" in 10 cases (21.3%) of those diagnosed as CD in 2 respects: (a) changing the diagnosis from irritant to allergic CD (6 cases) and (b) changing the diagnosis from CD to a suspected substance, to CD to another unsuspected substance (4 cases). For EE and UE, the initial diagnosis was changed to allergic CD in 3 (18.7%) and 7 (28.0%) cases, respectively.

Climate

Smoking among medical students in Hong Kong.

A survey was conducted among two classes of medical students (N = 293) at the University of Hong Kong to study their smoking habits and knowledge of and attitudes toward smoking. The response rate was 97.3%. There was only one daily smoker (0.4%) and 21 occasional smokers (7.4%). While the respondents regarded health and self-discipline as the main reasons for not smoking, the social taboo against smoking among young people might have also deterred this educated elite from smoking. Many of them failed to identify the major causal role of smoking in smoking related diseases. The potential of prevention in encountering a smoking patient seen for reasons unrelated to smoking was not fully realised. There was disagreement in the banning of cigarette advertising and in increasing the price of tobacco products. In the face of aggressive marketing by the tobacco industry in the Asia-Pacific region, every undergraduate medical curriculum should include organized instruction on smoking and its control.

Adult

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

Analysis of some individual risk factors for decompression sickness in Hong Kong.

Individual risk factors for decompression sickness (DCS) were studied in 932 men who had worked for 12 shifts or more at maximum working pressure (MWP) of 1 bar or above in a compressed air tunneling project in Hong Kong. Two dependent variables were used: presence or absence of bends and number of bends experienced by a man. Three hundred and fifty-six men (38.2%) had one or more bends. Univariate analysis showed that many variables were associated with presence or absence of bends. Logistic regression showed that the best equation included five independent variables: MWP, number of exposures, past number of bends, job (being a miner), and Quetelet Index (or Body Mass Index). The number of bends was also associated with many variables. Stepwise multiple regression revealed five important independent variables: ethnicity, MWP, Quetelet Index, number of exposures, and past number of bends. Obesity and past number of bends were therefore important risk factors for DCS after taking into account MWP and number of exposures. The age effect observed in univariate analysis could be due to obesity. Miners and Japanese had higher risks of DCS, probably due to their strenuous labor.

Adult