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Biomedical subjects

J Woo

Publications and source records attributed to J Woo.

At least 217 records · Page 12Linked to original sources

The differential regulation of insulin-like growth factor (IGF) binding proteins by IGF-I during the life span of the rat.

To evaluate the therapeutic potential of insulin-like growth factor-I (IGF-I) as an anabolic agent during aging, we determined its effects on IGF binding proteins (BPs) in male rats of 2, 8, 16, and 24 months of age. In control animals, a striking increase (143%) in the predominant 39-45 kDa serum IGFBP (BP-3), with little change in serum IGF-I, accompanied the marked deceleration of growth which occurred between 2 and 8 months; the levels of IGF-I and its BPs declined by 15% and 34%, respectively, later in life. Infusion of IGF-I (1.2 mg/kg/day) for 2 weeks produced progressively larger increases in circulating IGF-I with age, from 24% to 95% between 2 and 24 months, consistent with an age-related decrease in exogenous IGF-I clearance. We attributed these results to the large increase in IGFBPs that occurred with maturation, as well as an induction of IGFBP-3 (34-68%) and a larger increase in the 30-34 kDa IGFBP (BP-2; 136-235%) following IGF-I treatment in the older (16-24 months) animals. Anabolic actions of IGF-I, which were seen only in the older rats, included modes increases in weight velocity (5.2 +/- 1.2 g/week), serum phosphorous (20%), and alkaline phosphatase (26%) compared to age-matched controls. In conclusion, differential changes in the relative levels of the different IGFBPs with IGF-I treatment in older animals appeared to profoundly influence both the half-life and tissue accessibility of exogenous IGF-I, thus modulating the potential benefits of IGF-I as an anabolic agent during aging.

Aging↗

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.

Aged↗

Circulating intercellular adhesion molecule-1 (ICAM-1) in autoimmune liver disease and evidence for the production of ICAM-1 by cytokine-stimulated human hepatocytes.

A circulating form of the membrane-bound ICAM-1 (CD54), a ligand for lymphocyte function-associated antigen-1 (LFA-1), has recently been identified in normal human serum. In this study, serum levels of soluble ICAM-1 (sICAM-1) were determined by sandwich ELISA both in normal healthy individuals of both sexes and in subjects with autoimmune liver diseases. Patients with primary biliary cirrhosis (PBC), primary sclerosing cholangitis and chronic active hepatitis (autoimmune) showed significant elevations in sICAM-1 compared with normal healthy subjects. The median level in PBC was approximately seven-fold above normal. Significant elevations in sICAM-1 were also detected, however, in patients with inactive alcoholic cirrhosis, suggesting that impaired liver clearance might at least in part account for the increased serum levels seen in patients with autoimmune liver disease. In patients with PBC, sICAM-1 levels were related to summary assessment of disease severity (Child-Pugh classification) and correlated significantly with serum biochemical indices of liver function, including measures both of cholestasis and liver cell injury. In contrast, serum levels of E-selectin did not differ significantly from healthy controls. Although it has been suggested that peripheral blood mononuclear cells (PBMC) may be a source of sICAM-1, investigation of ICAM-1 gene expression by reverse transcriptase polymerase chain reaction revealed similar basal levels of ICAM-1 message in PBMC of normal individuals and those with active PBC. This suggests that PBMC may not be a significant source of sICAM-1 in this disease. Similar increases in ICAM-1 mRNA expression were found in cultured, concanavalin A (Con A)-stimulated lymphocytes of both PBC patients and controls. Significantly, stimulation of cultured, normal human hepatocytes with proinflammatory cytokines and endotoxin induced cell surface expression of ICAM-1 and the secretion/shedding of sICAM-1 into the hepatocyte culture medium. This new finding suggests that hepatocytes may be an important source of sICAM-1 in autoimmune and other chronic liver diseases. The possible role of sICAM-1 in inflammatory disorders remains to be determined.

Adolescent↗

Hearing preservation in acoustic neuroma surgery.

Hearing conservation in acoustic tumour surgery remains controversial. There have been few previous reports in the British literature. The senior author has managed 24 patients by retrosigmoid surgery with the intention of preserving hearing during the last 9 years. The clinical features, surgical technique and results are discussed with respect to pre-operative selection criteria, and post-operative quality of hearing. Hearing preservation has been achieved in 11 (78.6%) of 14 patients with small or intracanalicular tumours and a mean minimum auditory threshold of 35 dB and 70% speech discrimination, the majority (81.8%) above the 50 dB/50% level. Tumour filing the fundus of the internal auditory canal was found to be a significant adverse prognostic factor as regards successful hearing preservation. Tumour excision was complete in all patients. Nearly 90% of patients had normal facial function, and the remaining 10% grade II function. Associated morbidity was minimal. It is suggested that the potential for hearing conservation should be considered as a factor in the management of patients with small acoustic neuromas.

Adult↗

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.

Aged↗

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↗

Association between serum uric acid and some cardiovascular risk factors in a Chinese population.

The association between serum uric acid concentration and some cardiovascular risk factors was examined in a working Hong Kong Chinese population (mean age 38 years), consisting of 910 men and 603 women. There was no significant age-related rise in serum uric acid concentration. Positive associations were found between serum uric acid concentration and body mass index, waist hip ratio, systolic and diastolic blood pressure, urea, creatinine, protein, glucose (fasting and 2 hours after 75 g oral glucose load), 2 hour insulin, triglycerides, and apolipoprotein B in men. Similar, but fewer, associations were seen in women, with the addition of a positive association with age. In both sexes, serum uric acid was negatively associated with high-density lipoprotein cholesterol. These findings complement the well-known clinical association between gout and cardiovascular and metabolic diseases, such as hypertension, hyperlipidaemia and diabetes mellitus, and suggest that serum uric acid may be a marker for the presence of an adverse cardiovascular risk factor profile.

Adult↗

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.

Aged↗

Pilot study of low-molecular-weight heparin in the treatment of acute ischemic stroke.

BACKGROUND: Our purpose was to assess the feasibility and risk of performing a double-blind placebo-controlled study of low-molecular-weight heparin in the treatment of acute ischemic stroke. SUMMARY OF REPORT: Fifty-five patients were treated within 48 hours of stroke onset. Pretreatment computed tomography was performed to rule out cerebral hemorrhage. Fraxiparine (6000 IU per day) was given subcutaneously for 7 days. No adverse reaction was encountered during the treatment period. At 3 months, 26 patients were independent, 21 moderately disabled, 4 severely disabled, and 4 dead. CONCLUSIONS: It would be safe and practical to conduct a clinical trial on the use of Fraxiparine in the treatment of acute ischemic stroke.

Acute Disease↗

Proofreading performance by disabled adults.

The development of Optical Character Recognition and other data input technologies is providing disabled individuals access to occupations in electronic data processing. Many of these technologies require proofreading of previously captured data for prolonged periods of time. Research using other tasks requiring sustained attention has demonstrated steep performance decrements over time by many functionally impaired populations. Previous investigations have suggested that gains in proofreading performance may be achieved by increasing the error density in the material to be proofread. Thus, the present study was designed to assess the performance of a heterogeneous group of 12 disabled persons on a computerized proofreading tasks. Errors were embedded in alphanumeric code. The subjects included individuals with a broad range of physical or psychological impairments. After extensive training, all subjects participated in a 6-hr. proofreading task. The subjects corrected 96.6% of the errors embedded in 50,000 characters. Error detections were stable across six hours of proofreading. Implications for proofreading in applied settings are discussed.

Adolescent↗

Influence of FK 506 (tacrolimus) on circulating CD4+ T cells expressing CD25 and CD45RA antigens in 19 patients with chronic progressive multiple sclerosis participating in an open label drug safety trial.

We have taken the opportunity of a clinical trial of the potential efficacy and safety of FK 506 (tacrolimus) in chronic progressive multiple sclerosis (MS) to examine the influence of this potent new immunosuppressant on circulating T-lymphocytes in an otherwise healthy non-transplant population. Peripheral blood levels of subsets of CD4+ T lymphocytes expressing the activation molecule interleukin-2 receptor (p55 alpha chain; CD25) or the CD45RA isoform were determined sequentially in 19 patients that were treated continuously with oral FK 506 (starting dose 0.15 mg/kg/day) for 12 months. No significant change in the proportion of circulating CD25+ CD4+ cells was observed over the study period in which the mean trough plasma FK 506 level rose from 0.3 +/- 0.2 to 0.5 +/- 0.4 ng/ml. There was also no significant effect of FK 506 on the percentage of CD45R+ CD4+ cells in the peripheral blood at 12 months compared with pretreatment values. Analysis of a subgroup of 7 patients, who showed a sustained reduction in CD25+ CD4+ cells and a reciprocal increase in CD45RA+ CD4+ cells for at least 6 months after start of treatment, did not reveal any difference in disability at one year compared with the treatment group as a whole. The side effects of FK 506 were mild and the overall degree of disability estimated by the mean Kurtzke expanded disability status scale (EDSS) score or the ambulation index did not deteriorate significantly in the 19 patients studied over the 12 months of FK 506 administration.

Administration, Oral↗

The advance of technology as a prelude to the laboratory of the twenty-first century.

Technological changes in the clinical laboratory are usually driven by the goal of patient care optimization. In the last decade, the trend appeared to be directed at clinical laboratory decentralization. A new generation of analytical instruments, the biosensors, is redirecting laboratory testing closer to the patient, at the bedside, in the physician's office, and by the patient at home. These miniaturized biosensors are easy to operate, require small specimen size, and provide reliable results with rapid TAT. Thus far, bedside testing using biosensor technology appears to offer unique opportunities for earlier availability of clinical laboratory data, decision making, and more specific diagnosis, and faster and more frequent monitoring; these may translate into improved patient care and reduced hospital costs. It is likely that this trend will continue into the twenty-first century. Electrochemical sensors (e.g., for electrolytes, glucose, urea, and hematocrit) and pulse oximetry, having gained clinical acceptance, will probably be the leading instrumentation for bedside testing. Continuous monitoring either by near-infrared sensing technology or with an implantable sensor is valuable in the care of the critically ill patient. Acceptance for clinical use will depend on complete data integration and a favorable cost-benefit ratio.

Biosensing Techniques↗

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↗

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.

Aged↗