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Biomedical subjects

J Woo

Publications and source records attributed to J Woo.

At least 127 records · Page 7Linked to original sources
PubMed1998

Bone mineral density and body composition in patients with airflow obstruction--the role of inhaled steroid therapy, disease and lifestyle.

BACKGROUND: Inhaled steroid therapy has been shown to be associated with low bone mineral density (BMD) in asthmatic patients, but its effect in men has not been specifically studied; and the relative importance of therapy, disease and lifestyle leading to low BMD has not been investigated. OBJECTIVES: The study was designed to compare BMD in women and men who had airflow obstruction (asthma or COAD with or without inhaled steroid therapy) with normal controls. The role of inhaled steroid treatment, disease severity and lifestyle was studied among patients. METHODS: One hundred and fourty-four patients (106 on inhaled steroids and 38 not on inhaled steroids) and 212 age-matched controls were studied. Body composition and BMD (at the total body, hip and spine) were measured by dual-X-ray densitometry (DEXA). Forced expiratory volume (FEV1) was measured in patients. A validated questionnaire was administered to measure lifestyle factors. RESULTS: The body mass indices (BMI) (P < 0.001) and percentage of body fat (P < 0.001) were higher among female patients on inhaled steroids than controls. However, the BMD of the total body (P < 0.05) and spine (P < 0.001) were significantly lower in premenopausal and postmenopausal women than controls, respectively (P < 0.005). The BMD at the spine (P<0.01) and hip (P < 0.01) in male patients were significantly lower than the controls. By multiple regression, age and use of inhaled steroid was negatively associated with BMD at the hip (P < 0.01), but not at the spine (P>0.05). Cigarette smoking was associated with significantly lower BMD at the femoral neck (P < 0.05), and a low dietary calcium intake was associated with lower BMD at the spine (P<0.05). In women, use of inhaled steroid was not associated with significantly lower BMD. CONCLUSION: Men who had asthma and/or COAD had lower BMD, and this was not attributable entirely to steroid use. Cigarette smoking and a low dietary calcium intake may partially account for this difference. The difference in BMD between female patients and controls, even in those taking inhaled steroid, was small.

Absorptiometry, Photon↗
PubMed1998

Nutritional status of elderly Chinese vegetarians.

AIM: To study the nutritional status of elderly Chinese vegetarians. SUBJECTS AND METHOD: Dietary intake (using the 24-h recall method), anthropometric indices and some nutritional laboratory parameters were studied in 131 elderly Chinese vegetarian women with a mean age of 81 years. Data from age- and sex-matched omnivore subjects from previous elderly surveys were used for comparison. RESULTS: Total energy, fat and protein calorie, thiamine, riboflavin and niacin intakes were lower in vegetarians than in non-vegetarians, while carbohydrate calorie, calcium, potassium, retinol equivalent and ascorbic acid intakes were higher. The 25th, 50th and 75th percentile for total body fat were lower and those for corrected arm muscle area were higher in vegetarians. Both urinary Na/Cr and K/Cr ratios were higher but the Na/K ratio was similar to that in non-vegetarians, as were mean systolic and diastolic blood pressures. Serum total cholesterol was lower, while serum triglyceride concentration was similar. The mean haemoglobin level was lower in vegetarians, the prevalence of anaemia being 30%, with deficiencies in B12 and/or iron accounting for 64% of the anaemia, compared with only 30% in non-vegetarians. Serum B12 concentration below the reference range occurred in 54% of the vegetarian subjects. Vegetarians also had a lower prevalence of a history of ischaemic heart disease; however, the prevalence of smoking was also lower. CONCLUSION: While the Chinese vegetarian diet may result in a favourable risk-factor profile for ischaemic heart disease, it is deficient in many B vitamins and gives rise to a high frequency of nutritional anaemias.

Aged↗
PubMed1998

Impact of chronic diseases on functional limitations in elderly Chinese aged 70 years and over: a cross-sectional and longitudinal survey.

OBJECTIVE: To examine the association of some common medical conditions with functional limitation in elderly Chinese aged 70 years and over, to estimate the percentage of disability attributable to individual diseases, and to attempt to identify predisposing factors by documenting the development of functional limitation over an 18-month period in those subjects with a particular disease who were independent initially. SUBJECTS AND METHODS: The cross-sectional data set consisted of 2,032 (999 M, 1,033 F) subjects aged 70 years and over recruited by random sampling (stratified by age and sex) of all recipients of old-age and disability allowance, which covers over 90% of the elderly population. Information regarding medical condition and functional assessment of ten basic activities of daily living using the Barthel Index were obtained by personal interviews and physical assessment of the respondents at their places of residence. The longitudinal data set consisted of 1,334 subjects with no functional limitation at baseline who were alive after 18 months. Functional status was reassessed. RESULTS: After adjusting for age and sex, diseases associated with severe functional limitation (Barthel Index < 15) were dementia, stroke, Parkinson's disease, and fractures. Those associated with mild to moderate functional limitation (Barthel Index 15-19) were the same, with the addition of asthma and diabetes mellitus. The attributable fraction for severe limitation was highest for stroke, dementia, and fractures. Stroke and arthritis were identified as diseases predisposing to mild to moderate functional limitation over an 18-month period among those subjects who were independent initially. CONCLUSION: Stroke, dementia, and fractures were the main chronic diseases associated with severe functional limitation in elderly Hong Kong Chinese. Attempts to reduce the disability burden in this population should target these diseases.

Age Distribution↗
PubMed1998

Nutrition and osteoporosis.

Nutritional factors have a significant influence on the cause of osteoporosis. Calcium supplementation may be particularly effective in populations with a low calcium diet. Supplementations of 500 mg/d may produce about 4% gain in skeletal calcium in adolescents. Supplementations of 800 mg/d may prevent bone loss in postmenopausal women. The results of clinical trials also suggested that such supplementation may prevent hip and vertebral fractures in the elderly. The largest effect of calcium supplementation occurs in the first year of treatment, whereas sustained effects are not proven. Vitamin D supplementation may be particularly useful in vitamin D-deficient elderly. In this group, hip fractures may be prevented by vitamin D administration. Urinary sodium excretion is correlated with urinary calcium excretion in humans, and a direct effect of high sodium intake on loss at the hip has been demonstrated. Observational epidemiologic studies suggested a negative effect of a high protein intake on bone density, although there are no results from clinical trials to support this view. Dietary fiber, phytate, oxalate, and caffeine intake may have a small negative effect on calcium absorption.

Age Factors↗
PubMed1998

Effect of nimodipine on memory after cerebral infarction.

OBJECTIVES: Epidemiological studies indicate widespread memory impairment in patients with stroke in the early post-ictal stage. Nimodipine may have psychopharmacological properties and may improve memory. We conducted a single-blind randomized controlled trial to determine whether nimodipine given 7-14 days after cerebral infarction improved memory. MATERIAL AND METHODS: One hundred patients with acute cerebral infarction were consecutively enrolled between D7 to D14. After stratification, patients were randomized to receive oral nimodipine 90 mg daily for 12 weeks, or no drug. Independent assessors administered Mini-Mental State Examination (MMSE) and Fuld Object-Memory Evaluation (FOME) at baseline, 6 weeks, and 12 weeks. RESULTS: Patients receiving nimodipine showed greater improvement in FOME mean scores at 12 weeks (P=0.0334), and also in FOME score change across time (P=0.0283). Patients with severe disability who received nimodipine also showed greater MMSE score change across time (P=0.0495). CONCLUSION: Nimodipine given 7-14 days after cerebral infarction for 3 months results in memory improvement.

Aged↗
PubMed1998

Dietary intake and practices in the Hong Kong Chinese population.

OBJECTIVES: To examine dietary intake and practices of the adult Hong Kong Chinese population to provide a basis for future public health recommendations with regard to prevention of certain chronic diseases such as cardiovascular disease, hypertension, and osteoporosis. PARTICIPANTS: Age and sex stratified random sample of the Hong Kong Chinese population aged 25 to 74 years (500 men, 510 women). METHOD: A food frequency method over a one week period was used for nutrient quantification, and a separate questionnaire was used for assessment of dietary habits. Information was obtained by interview. RESULTS: Men had higher intakes of energy and higher nutrient density of vitamin D, monounsaturated fatty acids and cholesterol, but lower nutrient density of protein, many vitamins, calcium, iron, copper, and polyunsaturated fatty acids. There was an age related decrease in energy intake and other nutrients except for vitamin C, sodium, potassium, and percentage of total calorie from carbohydrate, which all increased with age. Approximately 50% of the population had a cholesterol intake of < or = 300 mg; 60% had a fat intake < or = 30% of total energy; and 85% had a percentage of energy from saturated fats < or = 10%; criteria considered desirable for cardiovascular health. Seventy eight per cent of the population had sodium intake values in the range shown to be associated with the age related rise in blood pressure with age. Mean calcium intake was lower than the FAO/WHO recommendations. The awareness of the value of wholemeal bread and polyunsaturated fat spreads was lower in this population compared with that in Australia. There was a marked difference in types of cooking oil compared with Singaporeans, the latter using more coconut/palm/mixed vegetable oils. CONCLUSION: Although the current intake pattern for cardiovascular health for fat, saturated fatty acid, and cholesterol fall within the recommended range for over 50% of the population, follow up surveys to monitor the pattern would be needed. Decreasing salt consumption, increasing calcium intake, and increasing the awareness of the health value of fibre may all be beneficial in the context of chronic disease prevention.

Adult↗
PubMed1998

Genetic and environmental risk factors for Parkinson's disease in a Chinese population.

An epidemiological study of the environmental and genetic factors as well as the possible interplay between them was conducted among 215 patients with Parkinson's disease and 313 controls in a Chinese population in Hong Kong. In univariate analysis, a regular tea drinking habit was found to be a protective factor, which had not been reported before. Smoking (a protective factor), family history, duration of pesticide exposure (in years) in farming and pesticide exposure during farming in women (both risk factors) have been reported previously. In multivariate analysis, current smoking reached borderline significance at the 5% level and the variables, years exposed to pesticides and family history were significant at the 10% level. By contrast with the common occurrence of polymorphism of the CYP2D6 gene (a gene involved with xenobiotic metabolism) in white people, it is very rare in China and is not thought to be a significant factor contributing to Parkinson's disease in Chinese people.

Aged↗
PubMed1998

Cardiovascular risk factors and 18-month mortality and morbidity in an elderly Chinese population aged 70 years and over.

OBJECTIVE: To determine the influence of some cardiovascular risk factors (hypertension, diabetes mellitus, smoking habit, physical activity, obesity, adverse lipid profile) in elderly Chinese aged 70 years and over, on overall mortality and morbidity from stroke and ischaemic heart disease. DESIGN: Longitudinal study relating 18-month outcome to baseline values. SUBJECTS: 2,032 subjects (999 men, 1,033 women), mean age 80 years, recruited by random sampling of the Old Age and Disability Allowance Schemes, which covers 90% of the Hong Kong elderly subjects, stratified by sex and 5-year age groups from 70 years onwards. METHODS: At baseline, subjects were visited by interviewers to collect information regarding medical conditions, smoking habit, physical activity, and to measure their height, weight, skinfold thickness, and waist/hip ratio. A follow-up survey was carried out 18 months later to establish the development of any new stroke or ischaemic heart disease, and to note any deaths and the cause of such deaths from death certification. RESULTS: In multivariate analysis overall mortality was negatively associated with body mass index and participation in physical activity, after adjusting for age and sex. Death from stroke was associated with a higher systolic blood pressure at baseline. Among survivors, the only significant associations observed were a negative association between body mass index and the development of heart disease, and a positive association between systolic blood pressure and development of stroke. CONCLUSIONS: Few associations between cardiovascular risk factors and morbidity and mortality were demonstrated in elderly Chinese with a mean age of 80 years. The only modifiable risk factor appears to be systolic blood pressure.

Aged↗
PubMed1998

The reproducibility and usefulness of the oral glucose tolerance test in screening for diabetes and other cardiovascular risk factors.

We examined the reproducibility of oral glucose tolerance tests (OGTT) using the World Health Organization criterion in 212 Chinese subjects (male 149, female 63) who underwent two 75 g OGTTs within a 6-week period. The overall reproducibility was 65.6% (139/212) of which 74 subjects had normal glucose tolerance, 24 had diabetes and 41 had impaired glucose tolerance (IGT) on two occasions. The subjects were divided into three groups [group 1: normal OGTTs on both occasions (n = 74); group 2: one abnormal OGTT (either diabetes or IGT (n = 51); group 3: 2 abnormal OGTTs (n = 87)]. Subjects in group 1 were younger, had lower blood pressure, body mass index (BMI), waist-to-hip ratio (WHR), fasting and 2 h plasma insulin levels, triglyceride, very-low density lipoprotein and apolipoprotein-B concentrations than both groups 2 and 3. Group 2 had similar characteristics as group 3 except for a lower glycated haemoglobin (HbA1c), fasting and 2 h plasma glucose during the two OGTTs. With receiver operating characteristic curve (ROC) analysis, a HbA1c of 5.3% gave an optimal sensitivity of 70.7% and specificity of 74.3% to predict diabetes as defined by a 2 h plasma glucose value > or = 11.1 mmol/L in the first OGTT. Of the 212 subjects, 73 had HbA1c > or = 5.3%. The reproducibility of OGTT was 56.2% for these 73 subjects. With ROC analysis, a BMI of 25 kg/m2 gave an optimal sensitivity of 53.7% and specificity of 56.7% to predict diabetes. For the 36 subjects with BMI > or = 25 kg/m2, the reproducibility of OGTT was 58.3%. Similarly, for the 140 subjects with WHR > or = 0.9, the reproducibility of OGTT was 57.9%. These findings confirmed the poor reproducibility of OGTT which was not improved even amongst subjects with high HbA1c, BMI or WHR. Furthermore, subjects with one abnormal OGTT, whether reproducible or not, had a higher cardiovascular risk profile compared to subjects who had two normal OGTTs.

Adult↗
PubMed1998

Pain in Chinese cancer patients under palliative care.

Over a 4-month period, 218 Chinese patients with advanced cancer were admitted to a palliative care unit in Hong Kong. Ninety-five (44%) of them had pain. Of these 95, 70 (mean age 61.7 years) were evaluated with the visual analogue scale (VAS) and the numerical rating scale (NRS). Forty-two per cent of the 70 patients were illiterate. Eighty-three per cent had metastases. Eighty-seven per cent had pain due to the disease process. Forty-nine per cent had more than one pain, 54% had moderate pain and 20% had severe pain. The most common primary tumour was lung cancer. NRS scores strongly correlated with corresponding VAS scores, suggesting that NRS can routinely be used for pain intensity assessment in the Chinese. The study also showed that 64% of these patients with pain had moderate to severe disabilities to the basic activity of daily living, although there was no correlation between the severity of pain and the severity of disability.

Adult↗
PubMed1998

Use of the 1997 American Diabetes Association diagnostic criteria for diabetes in a Hong Kong Chinese population.

OBJECTIVE: Recently, the American Diabetes Association (ADA) has proposed revised diagnostic criteria for diabetes. Lowering of the fasting plasma glucose (FPG) cutoff value is intended to reduce the discrepancy with the 2-h plasma glucose (PG) cutoff value and to encourage the use of FPG. We have applied these new criteria to data collected from a population-based prevalence survey in Hong Kong Chinese subjects of working age. RESEARCH DESIGN AND METHODS: The results of 1,513 oral glucose tolerance tests (OGTTs) from a previously published prevalence survey of glucose intolerance and cardiovascular risk factors in a Hong Kong Chinese working population were reexamined using the new criteria. Of the 1,513 subjects, 27 had a known history of diabetes. Of the remaining 1,486 subjects, 228 were also selected randomly for a second OGTT without prior knowledge of the result of the first test. RESULTS: After exclusion of the 27 subjects with a known history of diabetes, the crude prevalence of diabetes was 2.83% (n = 42) when the World Health Organization's (WHO) criteria were applied. When the criterion of FPG > or = 7.0 mmol/l was used, as recommended by the ADA, the prevalence of diabetes was 1.41% (n = 21). Twenty-nine subjects (1.95%) with FPG < 7.0 mmol/l had a 2-h PG > or = 11.1 mmol/l. Eight subjects (0.53%), previously without a diagnosis of diabetes according to the WHO criteria (FPG < 7.8 mmol/l and 2-h PG < 11.1 mmol/l), had FPG between 7.0 and 7.8 mmol/l and were classified as having diabetes by the ADA criteria. This classification gave a net change of -1.42% in the prevalence of diabetes between the use of FPG > or = 7.0 mmol/l alone and the use of WHO criteria. Among the 1,486 subjects with no known history of diabetes, those classified as having diabetes according to the ADA FPG criterion alone had higher HbA1c and fructosamine levels than diabetic subjects defined by the WHO criteria. Of the 228 subjects for whom two FPG measurements were available, those who had consistent definitions (diabetes, impaired fasting glucose, normal fasting glucose) on both occasions were considered to have reproducible tests, giving an overall reproducibility of 90.8% (207 of 228). CONCLUSIONS: Compared with the WHO criteria, the use of FPG to diagnose diabetes, as recommended by the ADA, was a more reproducible test and identified those subjects who had a greater degree of hyperglycemia. Although lowering of the cutoff value from 7.8 to 7.0 mmol/l increased the number of diagnoses among subjects with low FPG, the omission of the 2-h PG would lead to fewer subjects having their diabetes diagnosed.

Adolescent↗
PubMed1998

Features for a B-ISDN telemedicine system and its application.

Telemedicine technology is emerging as a new way of medical practice. It will provide more cooperative activity between departments and more comfortable access for disabled patients home. We developed two types of telemedicine system: a telediagnosis system and a home care system. Our telemedicine application is aimed to be run on the broadband-integrated services digital network (B-ISDN). The legacy network is also considered. The user interface is designed to help doctors to communicate easily. The key elements of telemedicine systems are user friendly interface, medical multimedia database design highly refined display technique.

Computer Communication Networks↗
PubMed1998

Nutrition and health issues in the general Hong Kong population.

In Hong Kong, the chronic diseases that lead to mortality and morbidity, and contribute to disability include cardiovascular diseases, cancer, hypertension, osteoporosis, and diabetes mellitus. The role of nutrition as a risk factor for the development of these diseases has been described elsewhere. For the older population, adequate nutrition is important to maintain health, particularly with regard to the effect of nutrition on immunocompetence. Nutritional surveys of the general adult population show that although the intake pattern for cardiovascular health is good, follow-up surveys to monitor the pattern are needed. In the context of chronic disease prevention, decreasing salt consumption, increasing calcium intake, and increasing the awareness of the health value of fibre may all be beneficial actions. Educational efforts should be directed particularly at those with lower levels of education, since the poorly educated have been shown to have a less healthy diet and a greater prevalence of overweight individuals. Among the elderly, evidence of undernutrition has been documented in institutional settings and is associated with increased mortality. The diet of those residing in vegetarian homes has been shown to be deficient in many B vitamins, which results in a high frequency of nutritional anaemias. To help achieve an optimal nutritional status, nutrition screening programmes should become an integral part of the development of quality care programmes for institutions responsible for care of the elderly.

Journal Article↗
PubMed1998

Osteoporosis---is it really preventable?

Osteoporosis is a major public health problem in Hong Kong. For instance, in 1995, a total of 3783 hip fractures occurred, with an associated acute care cost of HK$150 million. Thirty percent of elderly women in Hong Kong are known to have one or more vertebral fractures. The main risk factors for osteoporotic fracture in the Hong Kong Chinese population include a low dietary calcium intake, an inactive lifestyle, smoking, and frequent falls. Prevention for high-risk individuals involves the bone mineral density measurement followed by drug treatment. In a population-based approach, the entire population is targeted for the removal of risk factors. Osteoporosis in Hong Kong is potentially preventable, provided that the medical profession and the public can be motivated to participate, and adequate resources allocated for its prevention and treatment.

Journal Article↗
PubMed1997

Immunosuppression by D-isomers of HLA class I heavy chain (amino acid 75 to 84)-derived peptides is independent of binding to HSC70.

BACKGROUND: Peptides derived from the class I heavy chain were shown to modulate immune responses in vitro and in vivo. A peptide derived from HLA-B2702 (2702.75-84) inhibited differentiation of cytotoxic T cells as well as T cell and natural killer cell-mediated cytotoxicity in vitro. Peptide-mediated immunomodulation seemed to be independent of the MHC proteins expressed by responder and stimulator cells. In vivo studies in rodents demonstrated prolongation of heart and skin allograft survival after peptide therapy. Here, the correlation between the peptide's biological activity and its amino acid sequence was analyzed using peptides derived from amino acid 75-84 of several mouse, rat, and human MHC class I proteins as well as peptides with single amino acid substitutions in the 2702.75-84 sequence. METHODS: Peptides consisting of both L- and D-amino acids were tested for inhibition of murine and human T cell-mediated and lymphokine-activated killer cell-mediated cytotoxicity, binding to hsc70, and prolongation of heart allograft survival in vivo. RESULTS: Replacement of glutamic acid residue (E) at position 75 with valine (V) resulted in a peptide [2702.75-84(E>V)] with increased in vitro and in vivo activity but unchanged affinity for hsc70. Surprisingly, both L- and D-isomers of 2702.75-84 and 2702.75-84(E>V) inhibited cytotoxic cells in vitro and prolonged heart allograft survival in vivo. However, as expected, the peptides consisting of D-amino acids did not bind to hsc70. CONCLUSION: Assuming that both D- and L-isomers modulate immune responses by similar mechanisms, these results suggest that the peptides' effect is independent of binding to hsc70.

Adenosine Triphosphatases↗
PubMed1997

The effect of age on cardiovascular risk factors in Chinese women.

Chinese women traditionally have a low incidence of coronary heart disease. However, information on cardiovascular risk factors in this population are relatively scarce. We examined these risk factors in 601 Hong Kong Chinese women (age+/-SEM, 38.5+/-0.4 years; range, 18-66 years) stratified into four age groups (group 1, < or =30 years; group 2, 31-40 years; group 3, 41-50 years; group 4, > or =51 years). Increasing age in Chinese women was associated with increased body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, fasting plasma total cholesterol, triglyceride, low-density lipoprotein, apolipoprotein B, fasting and 2-h plasma glucose, glycated haemoglobin, fasting plasma insulin and urate concentrations. After adjustment for body mass index, waist-to-hip ratio and smoking, all these age-related associations remained statistically significant except for fasting plasma insulin concentration. There was a progressive increase with age in the prevalence of glucose intolerance, hypertension, dyslipidaemia and obesity. These prevalence rates further increased in subjects aged 51 years (the mean menopausal age in Asian women) or above. These findings suggest that age had an important and independent effect on cardiovascular risk in Chinese women and that, as in Caucasians, the onset of menopause might further increase this risk.

Adolescent↗