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Biomedical subjects

J Woo

Publications and source records attributed to J Woo.

At least 145 records · Page 8Linked to original sources
PubMed1997

Randomised trial of eradication of Helicobacter pylori before non-steroidal anti-inflammatory drug therapy to prevent peptic ulcers.

BACKGROUND: Helicobacter pylori infection is common in patients with peptic ulcers caused by the use of non-steroidal anti-inflammatory drugs (NSAIDs). But the pathogenic role of H pylori in this disease is controversial. We studied the efficacy of eradication of H pylori in the prevention of NSAID-induced peptic ulcers. METHODS: We recruited patients with musculoskeletal pain who required NSAID treatment. None of the patients had previous exposure to NSAID therapy. Patients who had H pylori infection but no pre-existing ulcers on endoscopy were randomly allocated naproxen alone (750 mg daily) for 8 weeks or a 1-week course of triple therapy (bismuth subcitrate 120 mg, tetracycline 500 mg, metronidazole 400 mg, each given orally four times daily) before administration of naproxen (750 mg daily). Endoscopy was repeated after 8 weeks of naproxen treatment or when naproxen treatment was stopped early because of bleeding or intractable dyspepsia. All endoscopic examinations were done by one endoscopist who was unaware of treatment assignment. The primary endpoint was the cumulative rate of gastric and duodenal ulcers. FINDINGS: 202 patients underwent endoscopic screening for enrolment in the trial, and 100 eligible patients were randomly assigned treatment. 92 patients completed the trial (47 in the naproxen group, 45 in the triple-therapy group). At 8 weeks, H pylori had been eradicated from no patients in the naproxen group and 40 (89%) in the triple-therapy group (p < 0.001). 12 (26%) naproxen-group patients developed ulcers: five had ulcer pain and one developed ulcer bleeding. Only three (7%) patients on triple therapy had ulcers, and two of these patients had failure of H pylori eradication (p = 0.01). Thus, 12 (26%) patients with persistent H pylori infection but only one (3%) with successful H pylori eradication developed ulcers with naproxen (p = 0.002). INTERPRETATION: Eradication of H pylori before NSAID therapy reduces the occurrence of NSAID-induced peptic ulcers.

Anti-Bacterial Agents↗
PubMed1997

Plasma total antioxidant capacity in an adult Hong Kong Chinese population.

OBJECTIVES: To examine plasma total antioxidant capacity (TAOC) in a Chinese population with a lower incidence of cardiovascular disease compared with Caucasian populations, in relation to dietary intake, age, sex, and the presence of cardiovascular diseases. DESIGN AND METHODS: As part of a randomized territory-wide survey stratified by sex and 10-year age groups; 728 subjects (367 men, 361 women) were recruited. Dietary intake assessment was by a food frequency questionnaire; plasma TAOC was estimated by the ABTS method. RESULTS: The TAOC values were normally distributed, the mean +/- SD being 1.78 +/- 0.18 mmol/L. The mean value was higher in men compared with women, inspite of a lower dietary intake of vitamins A and C per 1000 kcal in the former. Subjects who consumed water spinach twice or more a week had higher mean levels. No difference in mean levels was observed between those with and without hypertension or cardiovascular disease. CONCLUSION: Measurement of plasma TAOC as a risk factor in epidemiological studies of cardiovascular diseases may have limited use, since TAOC include substances associated with a protective effect as well as increased risk.

Adult↗
PubMed1997

Monoclonal antibody to the HLA class I alpha 3 domain inhibits T cell activation and prolongs cardiac allograft survival in HLA-transgenic mice.

Antibodies recognizing MHC class I molecules expressed on the surface of T cells have been shown to inhibit T cell responses in vitro. These findings suggested that therapy with such an antibody may prevent rejection and promote graft acceptance. We therefore tested the effect of an anti-HLA class I alpha 3 domain antibody (TP25.99) in vivo using transgenic C57BL/6 mice expressing HLA-B2705. Flow cytometric analysis confirmed the binding of TP25.99 to normal human peripheral blood lymphocytes and to mouse spleen cells, bone marrow cells and thymocytes isolated from hemizygous (+/-) transgenic littermates but not from homozygous (-/-) littermates. TP25.99 inhibited OKT-3-induced, but not PMA+ionomycin-induced, proliferation of human peripheral blood lymphocyte as well as anti-CD3 or Con A-induced proliferation of HLA+ mouse T cells. Both intact monoclonal antibody TP25.99 and TP25.99 Fab inhibited T cell proliferation. Reduced proliferation was associated with suppressed production of interleukin-2 as measured by ELISA. The efficacy of TP25.99 Fab in vivo was evaluated in a heart allograft model. Antibody therapy of (H-2h, B2705+) transgenic recipients of allogeneic Balb/c (H-2d) heart grafts prolonged graft survival significantly (MST = 19.8 +/- 6.4, p = 0.003) compared to treated (H-2b, B2705-) (MST = 9.17 +/- 2.2) or untreated (H-2b, B2705+) (MST = 10.0 +/- 2.8) transgenic recipients. This demonstrates that immunomodulation through anti-HLA class I antibody therapy can lead to prolongation of graft survival.

Animals↗
PubMed1997

Dietary practices and lipid intake in relation to plasma lipid profile in Hong Kong Chinese.

OBJECTIVE: To study dietary lipid intake and plasma lipid profile of the Hong Kong Chinese population as part of a territory wide survey on cardiovascular risk factors. DESIGN: Randomised age and sex stratified survey. SUBJECTS: 1010 subjects aged 25-74 y (500 men, 510 women). MEASUREMENTS: A food frequency method with food tables compiled for Hong Kong was used for nutrient quantitation, while a separate questionnaire was used to examine dietary practices. Plasma lipid profile was estimated using standard laboratory methods. RESULTS: Total calorie, fat, saturated fatty acid (SFA), poly- and mono-unsaturated fatty acid (PUFA and MUFA), and cholesterol intake were higher in men; however when adjusted for caloric intake no difference was observed. Men had lower intake of PUFA as percentage of total energy had a higher Hegsted Score compared with women. Subjects consuming beans twice or more per week had lower total cholesterol and LDL-cholesterol concentrations. Overall, the population dietary intake was close to the ideal for cardiovascular health: percentage fat not greater than 30% of the total calorie intake, saturated fat intake not greater than 10% of calories, and cholesterol less than 180 mg/1000 Kcal. CONCLUSION: The dietary pattern for Hong Kong Chinese appear to be satisfactory with respect to cardiovascular health.

Adult↗
PubMed1997

The reliability of upper limb anthropometry in older Chinese people.

OBJECTIVE: To evaluate the validity of the Durnin-Womersley equations and to derive our local predictive equations for body fat from upper limb skinfold thicknesses in older Chinese people in Hong Kong. To evaluate the validity of mid-arm circumference and corrected arm muscle area in predicting lean tissue mass in the same population. DESIGN: Comparison of fat percentages predicted by Durnin-Womersley (D-W) equations with those estimated by Dual energy X ray absorptiometry (DXA). Predictive equations derived from regression between upper limb skinfold thicknesses and fat percentages estimated by DXA were similarly evaluated in internal and external validation groups. Mid-arm circumference (MAC) and corrected arm muscle area (CAMA) were correlated with the limb lean tissue mass, body lean tissue mass and fat percentage. SUBJECTS: 354 female and 263 male, apparently well, community dwelling subjects, aged 69-82 y; of which 40 subjects of each sex were randomly selected from the study population for internal validation of the local predictive equations; 60 female and 33 male hospital medical outpatients, aged 61-87 y, were recruited for external validation. MEASUREMENTS: Triceps and biceps skinfold thicknesses, mid-arm circumference, body mass index, fat percentages, limb and whole body lean tissue masses estimated by Hologic QDR-2000 bone densitometer. RESULTS: Fat percentages calculated by D-W equations were significantly different from those estimated by DXA (average difference -2.4 (s.d. 4.8)% and +2.1 (5.2)% in females and males respectively). The corresponding differences for our local predictive equations were not significant (-0.9 (4.7)% and -0.5 (5.0)% in females and males respectively). There was a trend of under-estimation of body fat with increasing fatness. In the hospital medical outpatients, there was a significant difference between fat percentages predicted by our equation and those by DXA in female (-2.9(5.3)%), but not in male (+0.3(4.3)%) subjects. In males, MAC correlated with limb and body lean tissue masses as well as with fat percentage (r = 0.60, 0.68, 0.65 respectively). CAMA correlated similarly well with lean tissue masses but was more independent of fat percentage (r = 0.61, 0.65, 0.44 respectively). In females, both MAC and CAMA correlated poorly with limb and body lean tissue masses. Moreover, MAC correlated well with fat percentage (r = 0.80). CONCLUSION: Upper limb skinfold thicknesses measurement is a valid means of predicting body fat in older Chinese people. Local predictive equations were more reliable that D-W equations. They were, however, subject to errors at the extreme ends of body fatness and in the presence of disease. In older females, MAC and CAMA were not reliable in predicting lean tissue mass, but MAC could be used to predict fat percentages. In older males, CAMA was more reliable than MAC in predicting lean tissue mass.

Absorptiometry, Photon↗
PubMed1997

Simple anthropometric indexes and cardiovascular risk factors in Chinese.

OBJECTIVE: Obesity is a major public health problem due to its associations with multiple cardiovascular risk factors. Although there are sophisticated methods, such as imaging, to document total body fat and its distributions, anthropometric measurements remain important in clinical practice. We examined the relationships between cardiovascular risk factors and the three commonest anthropometric measurements for obesity, body mass index (BMI), waist-hip ratio (WHR) and waist circumference (WC), in Hong Kong Chinese subjects. DESIGN AND SETTING: The data are obtained from a prevalence survey for glucose intolerance and lipid abnormality in a representative Hong Kong Chinese working population. All employees from a public utility company and a regional hospital were invited to participate. SUBJECTS: There were 1513 subjects (910 men and 603 women, mean age +/- s.e.m.: 37.5 +/- 0.2 y). All of them had no significant past medical history. MEASUREMENTS: BMI, WHR and WC of the 1513 subjects were assessed for their relationships with various cardiovascular risk factors. These include blood pressure, fasting and 2 h plasma glucose and insulin, glycated haemoglobin, total cholesterol, triglyceride, high density and low density lipoprotein cholesterol, and urine albumin concentration. RESULTS: After age adjustment, all three anthropometric indexes were significantly correlated with the major cardiovascular risk factors in both men and women. When BMI, WHR and WC were analysed according to quartiles, there was a significant trend for blood pressure, plasma triglyceride, fasting and 2 h plasma glucose and insulin to increase, and high density lipoprotein cholesterol to decrease, with increasing obesity after adjustment for age and smoking. Using stepwise regression analysis with the three indexes as independent variables, most of the variance in blood pressure, plasma lipid, insulin, glucose and urinary albumin concentration were explained either by WC or WHR. In women, BMI was the main explanatory variable for reduced high density lipoprotein cholesterol. CONCLUSIONS: In Hong Kong Chinese, BMI, WHR and WC provide important information in assessing cardiovascular risks. In men, central adiposity as reflected by WC and to some extent, WHR, explained most of the variance in blood pressure, plasma glucose, lipid, insulin and albuminuria. In women, all three indexes reflecting general and central obesity contribute to the variance in these risk factors.

Adult↗
PubMed1997

Predictors of mobility decline: the Hong Kong old-old study.

BACKGROUND: Old age is often accompanied by functional decline and loss of autonomy. This longitudinal study examines the factors associated with mobility decline among a Chinese elderly cohort aged 70 years and above. METHODS: Analyses were carried out on data collected from 1,483 elderly subjects who were functionally mobile at baseline and survived the 18-month follow-up period. The outcome variable "mobility decline" was measured using the Barthel Activities of Daily Living Scale, which accesses subjects' ability to be independent in walking a distance of 50 meters and/or moving up and downstairs during the 18-month follow-up interview. RESULTS: Multivariate backward stepwise logistic regression analysis revealed that the following baseline characteristics were independently associated with mobility decline during the follow-up period: increasing age (OR 1.4, 95% CI 1.2-1.6 for every 5-year increase in age), no formal level of education (OR 1.9, 95% CI 1.0-3.9), no current practice of exercise (OR 2.1, 95% CI 1.4-3.1), symptoms of palpitation (OR 1.7, 95% CI 1.1-2.8), body mass index [weight (kg)/height (m)2] below 20 (OR 1.7, 95% CI 1.1-2.6), and slow gait velocity (OR 1.12, 95% CI 1.09-1.16 per second increase in gait time). There was also significant association between the experience of falls during follow-up and mobility decline (OR = 2.9, 95% CI = 1.9-4.5). CONCLUSION: Low body weight, lack of exercise, and falls during the follow-up period might serve as markers as to which subjects are at risk for mobility decline.

Accidental Falls↗
PubMed1997

Attitudes toward life-sustaining treatment of older persons in Hong Kong.

OBJECTIVES: There have been few studies of the attitudes of older Asians toward life-sustaining therapy. This paper presents the knowledge of and attitudes toward cardiopulmonary resuscitation (CPR) and life support in a group of subjects in Hong Kong. DESIGN: Cross-sectional, descriptive study. PARTICIPANTS: Of the 543 subjects, 382 were old-age home residents and 161 were in-patients of geriatric wards. MEASUREMENTS: Sociodemographic data, functional ability (using the Barthel Index), self-perceived health scale, knowledge of life-sustaining procedures, and subjects' preferences for such treatments were studied. They were also asked to give the most important reason for wanting or declining CPR, and to indicate who they believe should be the decision-maker(s) regarding whether they should receive life-sustaining treatment. RESULTS: Approximately 80% of old-age home residents and 60% of hospitalized patients had no knowledge of life-sustaining therapy. The success rate of CPR was overestimated by older subjects, and most wished to be resuscitated. However, up to 20% changed their minds and declined CPR after they knew the true outcome of the procedure. Half of the subjects wanted life support. Univariate analysis found that advanced age and not having a spouse were associated significantly with CPR preference, whereas subjects' knowledge was associated with preference for life support. Multivariate analysis revealed that advanced age, not having a spouse, and female sex were independently associated with a tendency to decline CPR. A considerable proportion of older people wished to be involved in decision-making regarding life-sustaining treatment. CONCLUSION: Knowledge of life-sustaining procedures was poor among older people in Hong Kong compared with their counterparts in western countries. Although most older subjects wanted CPR, a number of them changed their minds after they knew the poor outcome. Therefore, older patients should be given more information about life-sustaining therapy and encouraged to take part in their treatment plans.

Activities of Daily Living↗
PubMed1997

An estimate of chronic disease burden and some economic consequences among the elderly Hong Kong population.

OBJECTIVES: To estimate the burden of chronic disease for an elderly Chinese population aged 70 years and over, and to illustrate the use of this information in estimating the economic consequences of disease burden using stroke as an example. PARTICIPANTS: A total of 1902 subjects recruited by random sampling of the old age and disability allowance schemes, which cover over 90% of the Hong Kong elderly population, stratified by sex and five year age groups from age 70 years onwards. METHOD: Information was collected on 10 medical conditions at baseline: arthritis, hypertension, cardiac disease, stroke, chronic obstructive airways disease, peptic ulcer, diabetes mellitus, osteoporotic fracture, malignancy, and dementia. A follow up survey was carried out after 18 months to determine the occurrence of new disease and the number with disease who had died. Disease burden is calculated as the number with disease at baseline plus the number developing new disease minus the number who had died. RESULTS: Disease burden figures were highest for arthritis, hypertension, cardiac disease, and peptic ulcer, and were higher in the 70-79 age group than the 80+ age group for some diseases. For stroke, the economic cost based on a population projection for 2001 was estimated to be around HK$1,900,000,000, or US$250 million. CONCLUSION: Information on the burden of chronic disease is important. It enables the economic consequences to be estimated so that strategies can be developed to prevent diseases with high costs and known effective preventive methods.

Age Distribution↗
PubMed1997

Avoidable attendance at accident and emergency by the elderly in Hong Kong.

Twenty per cent of Accident and Emergency department attendance by the elderly in a regional hospital in Hong Kong were deemed 'avoidable' by the attending doctors. The 'avoidable' attendants were younger and physically more independent than the appropriate attendants, and more of them were illiterate. Half of them attended the Accident and Emergency department for somatic complaints. Strategies to reduce these 'avoidable' attendances should be formulated.

Aged↗
PubMed1997

Outcome after stroke rehabilitation in Hong Kong.

OBJECTIVE: To determine the outcome of patients discharged to the community after stroke rehabilitation. METHODS: One hundred and eighty-five consecutive patients discharged after stroke rehabilitation were enrolled for follow-up 12 months after discharge from a hospital in Hong Kong. A telephone interview to determine disability and place of residence was conducted. Disability was assessed by the Barthel Index and ratings of activities of daily living and mobility on a 4-point scale. RESULTS: One hundred and thirty-one patients or their carers were contacted (70.1%). This comprised 19 patients (10.3%) who died and 112 patients or their carers (60.5%) who were interviewed. Fifty-four patients (29.2%) were lost to follow-up. Comparison of the patients contacted and those lost to follow-up did not detect membership bias. Median Barthel Index of the surviving patients who were contacted rose from 90.0 (interquartile range 78.75-100.0) at discharge to 100.0 (interquartile range 85.0-100.0) at 12 months. Ratings of activities of daily living and mobility were maintained, with significant improvement in toileting. After rehabilitation 77.3% of the patients were discharged home and there was no significant change in residence at 12 months. Elderly patients (> or = 70 years old) had higher rates of institutionalization after hospital discharge and more disability although they achieved similar gains in Barthel Index and had similar lengths of hospital stay compared to younger patients. CONCLUSIONS: These results suggest that stroke patients were able to maintain their gains achieved during inpatient rehabilitation up to one year after discharge from hospital.

Activities of Daily Living↗
PubMed1997

Growth hormone response to the hypothalamic somatostatinergic activity in acromegalic patients.

Oral glucose administration suppresses the TRH-induced TSH response by enhancing the hypothalamic somatostatinergic activity (HSA). We assessed the HSA in 13 acromegalic patients by measuring glucose-induced suppression of TRH-stimulated TSH secretion. The HSA showed wide variation with up to 64% suppression. The mean HSA of the patients (25 +/- 6%) did not differ from that in normal young men (19 +/- 4%) in our previous study. Six patients had normal or low HSA, and the other 7 patients had high HSA. The mean TRH-stimulated TSH levels of the patients with normal or low HSA was significantly lower than that of the patients with high HSA (5.13 +/- 0.10 vs. 11.30 +/- 2.80 mU/L). The HSA did not relate to sex, age, tumor size, basal GH levels, the paradoxical responses to TRH and GnRH, octreotide response, or the gsp oncogene. In the combined glucose-TRH test, glucose pretreatment completely suppressed the paradoxical increase in GH level at 30 min in 4 patients. However, it could suppress the paradoxical GH response by only 6-51% in the other 5 patients who also showed the paradoxical response in TRH test. The tumor diameter of patients with good response to the HSA was significantly larger than that of the patients with poor response (31 +/- 5 vs. 14 +/- 2 mm) as was the tumor grade (3.3 +/- 0.3 vs. 1.7 +/- 0.2). This study supports the idea that a reduction of HSA is not a primary cause of acromegaly, and the HSA seems to increase to suppress the autonomous secretion of GH from the pituitary adenomas. HSA as well as the response of tumors to HSA do not determine tumor growth.

Acromegaly↗
PubMed1997

The dopamine transporter gene and Parkinson's disease in a Chinese population.

We studied a variable number tandem repeat polymorphism within the dopamine transporter gene (DAT) for an association with Parkinson's disease in a Chinese population. Five alleles were detected, consisting of 6, 8, 9, 10, and 11 copies of the 40 base pair repeat sequence. The 10-copy allele was most common, accounting for 90% of alleles. There were no significant differences between the patients and the control subjects in the distribution frequencies of the alleles or genotypes. Therefore, this polymorphism is not associated with Parkinson's disease in Chinese populations.

Aged↗
PubMed1997

Dichotomizing stroke outcomes based on self-reported dependency.

Patients participating in a clinical trial of stroke therapy were assessed 3 months after randomization using the Barthel Index, the Modified Rankin Scale, questions on activities of daily living, and extent of recovery. Those who needed help in performing the activities of daily living and had not recovered completely were classified as dependent. Self-reported dependency had a sensitivity of 94% and specificity of 80% against the Barthel Index dichotomized at 16 or below, or a sensitivity of 85% and specificity of 87% against the Modified Rankin Scale dichotomized at 2 or above.

Activities of Daily Living↗
PubMed1997

Fasting plasma glucose as a screening test for diabetes and its relationship with cardiovascular risk factors in Hong Kong Chinese.

OBJECTIVE: To evaluate the use of fasting plasma glucose (FPG) in the diagnosis of diabetes and the relationship between FPG and various cardiovascular risk factors in a community-based Hong Kong Chinese population. RESEARCH DESIGN AND METHODS: The results of 1,470 oral glucose tolerance tests from a prevalence survey for glucose intolerance and lipid abnormality in a Hong Kong Chinese working population were examined. Our previous report showed that an FPG of 5.7 mmol/l corresponded to a 2-h plasma glucose (PG) of 11.1 mmol/l, and we used this value as a cutoff value and examined the relationship between FPG and various cardiovascular risk factors in nondiabetic subjects. RESULTS: An FPG cutoff value of 7.8 mmol/l gave a sensitivity of 20.0% and a specificity of 100% in the diagnosis of diabetes (defined as 2-h PG > or = 11.1 mmol/l). We divided the non-diabetic subjects (FPG < 7.8 mmol/l and 2-h PG < 11.1 mmol/l) into two groups: subjects with FPG < 5.7 mmol/l and those with FPG > or = 5.7 mmol/l and < 7.8 mmol/l. Subjects in the latter group were older, had higher blood pressure, BMI, waist-to-hip ratio, 2-h PG, fasting and 2-h insulin, fasting serum triglyceride, VLDL cholesterol, apolipoprotein B, and urinary albumin concentrations, as well as lower plasma HDL cholesterol and HDL2 cholesterol concentrations. CONCLUSIONS: These findings suggest that an FPG cutoff value of 7.8 mmol/l, as recommended by the World Health Organization, was too high when applied to Chinese populations. As in the case of hyperlipidemia, plasma glucose concentration should be viewed as a continuum in terms of its relationship with cardiovascular risk.

Adult↗
PubMed1997

Invasive streptococcal infections. Report of four cases occurring in Trinidad.

Many countries are reporting a resurgence of virulent streptococcal strains but there is little information from the Caribbean. Four cases of severe invasive streptococcal infections, three of them fatal, are reported. The portal of entry was infected scabatic lesions in one patient and infected mosquito bites in another patient who developed cellulitis and gangrene; but no portal of entry was detected in the other patients. Group A beta haemolytic Streptococcus (GAS) was isolated from the blood of three patients, one of them GAS M type 3, which had the genome for streptococcal pyrogenic exotoxins A (SPeA) and B (SPeB). GAS M type 72, which had the genome for SPeB and SPeC, were isolated from the tissues (but not from the blood) of the patient who developed cellulitis and who was the sole survivor. Physicians in the Caribbean must be alerted to the presence of these virulent streptococcal strains, and must be prepared to manage serious invasive disease.

Adult↗