Biomedical subjects

S C Ho

Publications and source records attributed to S C Ho.

At least 109 records · Page 6Linked to original sources

PubMed1994

Risk factor change in older persons, a perspective from Hong Kong: weight change and mortality.

BACKGROUND: The influence of anthropometric measurements on mortality and longevity has been of interest to a number of investigators. However, although such measurements are not stable over time, few studies have attempted to account for such changes in longitudinal studies. The present study attempts to examine the relationship between weight change and mortality outcome. METHODS: The research was based on a longitudinal study of a cohort of 1,056 Hong Kong Chinese men and women aged 70 and above. Among the 476 nonsmoking women at baseline, 374 with weight measurements both at baseline and at 24 months follow-up were included in the study. Proportional hazards analysis with adjustments for age and other physical and social factors was used to estimate the relative risk of mortality of the higher body mass index groups in relation to the lowest body mass index group and between the weight change groups. RESULTS: Women belonging to the middle tertile of body mass index distribution had the lowest mortality. Those with a weight loss of more than 2 kg over the first 24 months follow-up had five times the risk of mortality at 40 months, even after adjusting for health and social conditions and baseline body mass index. CONCLUSION: The results suggest that both the initial body weight and weight change during the follow-up period are important considerations in the study of the association between body weight and mortality.

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PubMed1994

The prevalence of depressive symptoms and predisposing factors in an elderly Chinese population.

In a survey of elderly Chinese aged 70 years and over living in Hong Kong selected by stratified random sampling, the prevalence of depression was determined using the 15-item Geriatric Depression Scale using a cut-off point of 8 (sensitivity 96.3% and specificity 87.5% for this population). Subjects with moderate to severe cognitive impairment (CAPE I/O score < or = 7) were excluded. There were 877 men and 734 women. The adjusted overall prevalence for this population was 29.2% for men and 41.1% for women. The prevalence increased with age in men and was higher in women than in men. Univariate analysis identified many factors in the following areas that were associated with depression: socioeconomic characteristics, functional ability, physical health and social support. Stepwise logistic regression identified 16 factors predictive of depression: socioeconomic characteristics, such as borderline living expenses and dissatisfaction with living arrangement; poor social support, such as absence of an informal carer when ill, few relatives to turn to, and infrequent contact with neighbours and friends; functional disability, as indicated by a Barthel Index < 15, urinary incontinence and inability to do housework; and poor physical health--poor self perceived health, poor vision, difficulty with chewing, history of mental illness, frequent hospital admissions and increased level of symptoms such as poor memory, constipation and dizziness. Some of these factors may be amenable to intervention, and such measures may be important in reducing the high prevalence of depression in elderly people.

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PubMed1994

Age and marital status are major factors associated with institutionalisation in elderly Hong Kong Chinese.

STUDY OBJECTIVE: To determine the need for long term institutional care for elderly Chinese living in Hong Kong and factors associated with institutional living. DESIGN: Survey by interviewer administered questionnaire of a stratified random sample of all recipients of old age or disability allowance covering 90% of the population. SETTING: Survey performed in Hong Kong, a city on the south coast of China with an area of 1070 km2 and approximately six million people. PARTICIPANTS: A total of 2032 subjects aged 70 years and over (999 men, 1033 women) participated. MAIN RESULTS: Overall, 16% of the elderly live in institutions. The percentage is higher in women and in the older age group (81% for those aged 80 years and over). After adjusting for age and sex, the following factors were positively associated with institutionalisation: poor cognitive function, measures of functional disability, poor vision, Parkinson's disease, stroke, and past fractures. Multivariate analysis identified age and marital status as associated factors with the highest odds ratio (13.6 and 7.1 respectively), followed by various disability indicators. CONCLUSION: The survey shows that requirements for long term care places are unlikely to be much affected by preventive measures, and would need to increase by about 30% by 2000 to cope with the projected increase in the number of elderly aged 70 years and over. Measures to provide sufficient trained personnel and policy for regulation of standards should be made.

Activities of Daily Living↗

PubMed1994

Prevalence of cognitive impairment and associated factors among elderly Hong Kong Chinese aged 70 years and over.

The prevalence of cognitive impairment was determined in a random age- and sex-stratified sample of 2,011 elderly Hong Kong Chinese, aged 70 years and over, consisting of subjects living in the community and in institutions. The Information/Orientation Section of the Clifton Assessment Procedure was used as the screening instrument using a cutoff point of 7. The overall age-adjusted prevalence was 5% for men and 22% for women, and 15% for both sexes combined. Univariate analysis identified the following associated factors in order of magnitude of the odds ratio: age; history of Parkinson's disease; functional disability; female sex; low educational level; low social class; history of stroke, and low monthly income. Other diseases, such as heart disease, hypertension, chronic lung diseases or diabetes, were not associated factors. In multivariate analysis, all the above factors remained significant with the exception of a history of stroke. The prevalence figures are comparable to other Caucasian and Chinese studies, and the associated factors identified suggest that there may be room for prevention.

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PubMed1994

Musculoskeletal complaints and associated consequences in elderly Chinese aged 70 years and over.

OBJECTIVE: To determine the prevalence and sites of musculoskeletal complaints and some associated health consequences among elderly Chinese. METHODS: A random sample of all subjects aged 70 years and over stratified by age and sex. Information collected by questionnaire at an interview. RESULTS: Nineteen to 41% of subjects complained of pain at various sites restricting activities, with a higher prevalence for women. The most common 4 sites involved in order of frequency were knee, upper back, ankle/foot, and shoulder. Back pain increased with age in men to reach the same frequency as women in the 90+ age group. Between 6 to 10% of men and 9 to 14% of women used nonsteroidal antiinflammatory drugs. Pain limiting activities were associated with a lower Barthel index, use of walking aids, increased frequency of doctor consultations, sleep disturbance, and higher depressive symptom scores. CONCLUSION: Prevention of conditions resulting in musculoskeletal complaints would be important in the promotion of healthy active life expectancy in the elderly.

Age Factors↗

PubMed1993

Cardiovascular symptoms, electrocardiographic abnormalities, and associated risk factors in an elderly Chinese population.

The aim of this study was to determine the prevalence of angina and possible infarct (WHO cardiovascular questionnaire) and electrocardiographic abnormalities (Minnesota Coding) in elderly Chinese subjects aged 70+ years living in Hong Kong, and the association with some cardiovascular risk factors. A subsample of 197 subjects (96 men, 101 women) selected according to geographical area from a territory-wide health survey consisting of 2032 elderly subjects selected by an age and sex stratified random sampling method was studied. Overall, 7% of men and 9% of women had symptoms suggestive of angina, while 6% of men and 4% of women had symptoms suggestive of possible infarct. There were fewer symptoms in the 80+ age group. Forty-two percent of men and 35% of women had normal electrocardiograms. The prevalence of probable ischaemic heart disease (using the Whitehall Criteria) was 6% for men and 7% for women, while the figures for possible disease were 23% and 25%, respectively. The percentage with abnormalities increased with age. The prevalence of coronary heart disease defined by the presence of symptoms, a history of known disease plus use of medication, and electrocardiographic abnormalities suggestive of probable disease, was 26% for men and 27% for women. These findings were comparable with studies in elderly Caucasian populations. Only a higher socioeconomic grouping and lower HDL cholesterol were identified as associated risk factors. It is concluded that the prevalence of coronary heart disease in the elderly Chinese population in Hong Kong is at least as high in Caucasian populations, and few modifiable risk factors were identified in the elderly aged 70 years and over.

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PubMed1993

Carbohydrate binding activities of Bradyrhizobium japonicum: unipolar localization of the lectin BJ38 on the bacterial cell surface.

A polyclonal antiserum generated against the Bradyrhizobium japonicum lectin BJ38 was characterized to be specifically directed against the protein. Treatment of B. japonicum cells with this antiserum and subsequent visualization with transmission electron microscopy and both conventional and confocal fluorescence microscopy revealed BJ38 at only one pole of the bacterium. BJ38 appeared to be organized in a tuft-like mass, separated from the bacterial outer membrane. BJ38 localization was coincident with the attachment site for (i) homotypic agglutination to other B. japonicum cells, (ii) adhesion to the cultured soybean cell line SB-1, and (iii) adsorption to Sepharose beads covalently derivatized with lactose. In contrast, the plant lectin soybean agglutinin labeled the bacteria at the pole distant from the bacterial attachment site. These results indicate that the topological distribution of BJ38 is consistent with a suggested role for this bacterial lectin in the polar binding of B. japonicum to other cells and surfaces.

Antibodies↗

PubMed1993

Double-negative (L3T4-, Lyt2-) thymocytes of autoimmune lpr/lpr mice are resistant to down-regulation of DNA synthesis by a thymic stromal cell product.

The murine autosomal recessive gene, lpr, induces a progressive lymphadenopathy and lupus-like autoimmune syndrome characterized by the accumulation of immature, dull Thy 1.2+, TCR+, L3T4-/Lyt 2- (double-negative, DN) T cells in peripheral lymphoid organs. Previous studies demonstrated that the thymic microenvironment is required for the generation of the abnormal, peripheral DN T cells, while a more recent report linked the lpr gene defect with a failure of thymocytes to express a functional form of the Fas antigen, which mediates apoptosis. Thus, the lpr gene defect apparently prevents lpr thymocytes from responding to the ordered sequence of differentiation and proliferation signals involved in normal thymocyte maturation and selection. We compared the responses of thymocytes from C57BL/6 +/+ (normal) and congenic C57BL/6 lpr/lpr (lpr) mice to a thymic stromal cell product which down-regulates DNA synthesis in vitro. The results indicate that (a) thymic stromal cells from lpr mice produce a factor that can down-regulate DNA synthesis as efficiently as that from normal mice, even at an age when massive lymphadenopathy is present, (b) mitogen-stimulated thymocytes of normal, but not lpr, mice are sensitive to the inhibitory factor, (c) normal DN thymocytes are the cellular target of the inhibitory factor, which acts at some postmembrane receptor-ligand binding event during mitogen-stimulated proliferation, and (d) IL-4-dependent DN thymocyte proliferation seems to be the main target of the inhibitory factor.

Animals↗

PubMed1993

Lipids, lipoproteins and other coronary risk factors in Chinese male survivors of myocardial infarction.

OBJECTIVE: To assess the importance of an abnormal lipid profile as a risk factor in relation to non-biochemical risk factors, and to define the risk levels for lipid, lipoprotein and apolipoprotein in a Chinese population. PATIENTS AND METHODS: Serum lipids, lipoproteins, apolipoproteins and other cardiovascular risk factors were studied in 89 Chinese men 3 months after acute myocardial infarction and 56 controls. RESULTS: Cases had higher mean total cholesterol (TC), LDL- and VLDL-cholesterol, triglycerides and apolipoprotein B (Apo B), and lower mean HDL-cholesterol and apolipoprotein AI (Apo AI). Mean BMI was also higher, as was the prevalence of smokers and subjects with a history of hypertension. In univariate analysis, the odds ratios for TG > or = 1.6 mmol/l, LDL-cholesterol > or = 4.1 mmol/l, VLDL-cholesterol > or = 0.73 mmol/l, Apo B > or = 104 mg/dl were of the same order of magnitude as being a current smoker, having a BMI > or = 24.3 kg/m2, and a history of hypertension. High HDL-cholesterol (> or = 1.39 mmol/l) and Apo AI (> or = 139 mg/dl) were protective factors. The odds ratios for successively higher quartile values of cholesterol were not statistically significant. Multiple logistic regression identified smoking habit, history of hypertension, obesity, high Apo B and low Apo AI concentrations as independent risk factors for myocardial infarction. CONCLUSIONS: In a Chinese population, low serum Apo AI and high Apo B are risk factors for myocardial infarction of a comparable magnitude to smoking, hypertension and obesity.

Apolipoprotein A-I↗

PubMed1993

Dietary electrolytes and urinary natriuretic factors.

We examined the relationship between the excretion of electrolytes (sodium, potassium and calcium), dopamine and digoxin-like immunoreactive substance in 41 young healthy female subjects (age 18-23 years) in order to study the interaction of electrolyte intake on dopamine and digoxin-like immunoreactive substance--factors which have been postulated to have a pathogenic role in hypertension. Sodium excretion was significantly correlated with dopamine excretion (r = 0.545, P < 0.0005) and digoxin-like immunoreactive substance (r = 0.359, P < 0.02). There was also a significant correlation between calcium and digoxin-like immunoreactive substance (r = 0.345, P < 0.03). Stepwise multiple regression analysis further confirmed that sodium is the only contributor to dopamine excretion and calcium is the only contributor to digoxin-like immunoreactive substance (r2 = 0.114). We conclude that in young healthy subjects dopamine excretion is determined partly by sodium intake and that the excretion of digoxin-like immunoreactive substance is independent of sodium intake.

Adolescent↗

PubMed1993

A longitudinal study of the determinants of bone mass in Chinese women aged 21 to 40. I. Baseline association of anthropometric measurements with bone mineral density.

The bone mineral density of the lumbar spine (L2 to L4) and neck of the femur of 293 Chinese women aged 21 to 40 years was measured using a dual x-ray densitometer. The participants were recruited from subjects registered with the University Family Medicine Clinic in Hong Kong. Our cross-sectional data showed that maximal bone mass occurs in the early 30s. Both the spine and hip bone masses were observed to decline at a rate of around 1% per annum from the early 30s onward. Body weight, lean body mass, and body fatness were significantly associated with the mineral density of the spinal and femoral bones after or around the attainment of peak bone mass, while no correlation of these data was observed in the younger age group (20 to 28 years). Other factors may play a more important role than body mass in influencing bone mineral density before attainment of peak bone mass.

Absorptiometry, Photon↗

PubMed1993

Sunlight exposure, antioxidant status, and cataract in Hong Kong fishermen.

STUDY OBJECTIVES: The aim was to test whether cataract is associated with higher lifetime exposure to sunlight, and whether antioxidants protect against cataract. DESIGN: This was a cross sectional survey of eye disease, with assessment of antioxidant status in a subgroup. SETTING: Hong Kong fishing communities in 1989. PARTICIPANTS: 685 men and women aged 55 to 74 years old were included in the study, of whom 367 (54%) attended hospital for detailed examination. MEASUREMENTS AND MAIN RESULTS: At a mobile clinic visual acuity and lens opacities were assessed, and using a questionnaire, occupational history and lifetime exposure to sunlight. At hospital ophthalmic measurements were repeated and blood was taken for measurement of plasma vitamin C, vitamin E, and total carotenoids, and red cell activities of glucose-6-phosphate dehydrogenase, glutathione peroxidase, superoxide dismutase, and catalase. Higher grades of cataract (particularly nuclear cataract) tended to be more common in subjects with the most sun exposure, although not to the point of statistical significance. In contrast to earlier studies, no association was found with antioxidant status. CONCLUSIONS: The findings give some support to the hypothesis that sunlight causes cataract. The absence of a relation to antioxidant status may be because blood levels of antioxidants at one point in time do not adequately reflect a subject's past metabolic state, and particularly the past activity of antioxidants in the lens.

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PubMed1993

Lipid profile in the Chinese old-old: comparison with younger age groups and relationship with some cardiovascular risk factors and presence of diseases.

In a health survey of 2,032 elderly Hong Kong Chinese aged 70 years and over selected by stratified random sampling, a subset of 199 subjects (96 M, 103 F) were selected for a study of their lipid profile. No age and sex differences were observed in mean total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride concentrations in this subgroup. Compared with values from younger Chinese subjects from a previous survey, TC and LDL-C showed an age-related rise up till about 60 years, followed by a gradual decline. HDL-C concentrations showed little variation with age. Nonagenarians had a LDL/HDL ratio similar to subjects in the < 24 age group and lower than male subjects in the age 35-64 age group. HDL-C was lower in those with heart disease or hypertension. Other lipid parameters were not influenced by the presence of other chronic diseases, self-perceived health status, or cognitive impairment. TC was positively associated with the Barthel Index, a measure of functional ability. Positive associations between obesity indices and diastolic blood pressure, and TC, LDL-C, and triglycerides were present.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Hip fracture rates in Hong Kong and the United States, 1988 through 1989.

OBJECTIVES: Prior studies have suggested that hip fracture rates are substantially lower in Asian countries than in the United States. However, comparisons have been limited by unavailability of recent data, differences in case definition, lack of data from similar time periods, and small sample sizes. This study sought to examine trends by age and sex, with separate statistics for those aged 85 or older. METHODS: Hospital discharge data were used to obtain hip fracture incidence in Hong Kong and the United States from 1988 through 1989. RESULTS: Within each population, women had higher hip fracture rates than men. Fracture rates in the United States were significantly higher for both sexes than rates in Hong Kong. For persons over the age of 80, rates of hip fracture among White US males exceeded those for Hong Kong women. Inclusion of transferred cases in hip fracture rates minimized differences between the countries. CONCLUSIONS: Despite increasing hip fracture rates in Hong Kong, those rates are still substantially lower than the rates in the United States. Identifying factors responsible for this variation may prove useful in the search for preventive strategies.

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PubMed1993

Potassium intake and urinary calcium excretion in healthy subjects.

Potassium depletion increases and potassium supplementation decreases urinary calcium excretion. To determine whether these experimental observations have any significance in healthy free living subjects, we measured 24 h urinary calcium, sodium, potassium and serum parathyroid hormone (PTH) in 142 healthy young (aged 18-40 years) female Chinese subjects. Sodium excretion and potassium excretion were positively correlated with calcium excretion (r = 0.494, p < 0.0001 and r = 0.181, p = 0.031, respectively). However stepwise multiple regression analysis showed that only urinary sodium excretion contributed to the excretion of calcium. We conclude that in free living subjects potassium intake has little effect on calcium excretion.

Adolescent↗

PubMed1992

Catalytic properties of X-prolyl dipeptidyl aminopeptidase from Lactococcus lactis subsp. cremoris nTR.

An X-prolyl dipeptidyl aminopeptidase (X-PDAP; EC 3.4.14.5) was identified to be loosely bound on the inner cell membrane fraction of Lactococcus lactis subsp. cremoris nTR. The biosynthesis of X-PDAP was continuously increased before the late-log growth phase of the bacteria. Both Gly-Pro-pNA and Ala-Ala-pNA were hydrolyzed by X-PDAP; the kcat/Km value of the former was about 10-fold that of the latter. The Ki of X-Pro and Pro-X were more specific to X-PDAP than those of X-Ala. The enzyme splitting a dipeptide sequentially from beta-casomorphin as a model catalytic pattern was identified and some properties of the enzyme were further characterized.

Amino Acid Sequence↗

PubMed1992

Interrelationships between urinary sodium, calcium, hydroxyproline and serum PTH in healthy subjects.

The effect of sodium intake on the excretion of calcium, hydroxyproline (OHP) and serum parathyroid hormone (PTH) was examined. When seven healthy males increased their sodium intake by 200 mmol/day, excretion of calcium increased by 1.70 mmol/day and that of OHP by 27%. Serum PTH, however, did not increase significantly. In a cross-sectional study of 334 healthy female subjects there were strong positive correlations between fasting urinary sodium/creatinine (Na/Cr) and calcium/creatinine (Ca/Cr) ratios (r = 0.573) and between Na/Cr and urinary OHP/Cr ratios (r = 0.246). Serum PTH was negatively correlated with Na/Cr ratio (r = -0.161). We conclude that an increase in dietary sodium causes calciuria and an increase in hydroxyproline excretion. The results do not support the hypothesis that this is mediated by PTH.

Adult↗

PubMed1992

Blood pressure and 40 month mortality in elderly Chinese subjects aged 70 years and over.

The association between blood pressure and 4 year mortality was examined in a cohort of 970 Chinese subjects aged 70 years and above. After adjusting for age, sex, body mass index, smoking habit, place of residence, and the presence of heart or chronic lung diseases, a U-shaped association between blood pressure and mortality was observed, the risks of mortality among subjects in the extreme quartiles being twice as high as those in the middle quartiles. Subjects with the lowest systolic blood pressure quartile also had a higher risk of developing functional limitations.

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