Biomedical subjects
J Woo
Publications and source records attributed to J Woo.
Risk factors in non-insulin dependent diabetes mellitus in elderly Chinese in Hong Kong.
The early life environment, 24 h nutrient intake, body mass index, blood pressure and plasma zinc levels among 42 non-insulin dependent diabetic subjects living in sheltered housing were compared to 126 age and sex matched controls from the same community. A high body mass index and systolic blood pressure were the only risk factors. The association with systolic blood pressure was present only among non-obese subjects. No difference in nutrient intake was found. When nutrient intake from all 427 subjects living in sheltered housing was compared to other countries with a higher prevalence of NIDDM, the diet of Chinese subjects consisted of a lower percentage of fat calories and a higher percentage of protein and carbohydrate calories.
Immunosuppressive activity, lymphocyte subset analysis, and acute toxicity of FK-506 in the rat. A comparative and combination study with cyclosporine.
The immunosuppressive and toxic properties of the recently discovered macrolide antibiotic FK506 were examined in comparison and in conjunction with cyclosporine administration in the rat. Male Sprague-Dawley rats were immunized systemically with sheep erythrocytes and received, from the same time, either FK506 (1 mg/kg/day) intramuscularly or CsA (25 mg/kg/day) by gavage, or both drugs in combination. Seven days after immunization, the splenic plaque-forming cell response and circulating antibody titers were reduced greater than 90% in animals receiving either FK506 or CsA and in the drug combination group. These immunosuppressive effects of FK506 and CsA were accompanied by significant increases in the incidences of splenic OX-8+ cells and by corresponding reductions in the W3/25+:OX-8+ ratio. No further changes in T cell populations were observed in animals given both drugs. A progressive monocytosis was found in response to CsA, but not in FK506-treated rats. Increases in plasma urea were observed in FK-506 and drug-combination or CsA-treated rats on day 7, whereas creatinine levels were raised only in the FK-506 groups. Elevated bilirubin levels and alterations in liver enzyme activities were observed in CsA-treated rats by day 4, whereas FK-506 alone produced no similar effects. CsA-treated rats also exhibited elevated blood and urinary glucose levels from day 4. No biochemical evidence of additive drug toxicity was detected. The only histological abnormalities observed were thymic medullary atrophy in all drug-treated animals, together with very minor reductions in bone marrow cellularity in a proportion of those rats given FK-506. These findings show that, at the dosage selected, the powerful immunosuppressive activities of FK-506 were associated with little evidence of acute toxicity and with no indications of additive toxicity with CsA.
Biochemical predictors of short term mortality in elderly residents of chronic care institutions.
A survey of 208 elderly subjects living in four long term care institutions was undertaken over three months to identify nutritional and other variables that could be used to predict mortality during the subsequent three months. There were 58 men (mean age (SD) 75.6 (9.6) years) and 150 women (79.5 (8.4) years). Twenty nine subjects died (12 men and 17 women) within three months of completing the study. Twenty eight out of 57 variables differed significantly between those who died and those who survived. Subjects who died had lower systolic blood pressure, poorer intake of protein calories, lower concentrations of haemoglobin, plasma retinol, zinc, total cholesterol, and higher albumin adjusted plasma calcium concentrations. Stepwise regression analysis identified five variables that predicted mortality: plasma fructosamine; transferrin; glycosylated haemoglobin; prealbumin; and haemoglobin. The sensitivity, specificity, and predictive values of the discriminant function score using 0 as the demarcation between survivors and non-survivors were 75%, 97%, and 95%, respectively. This score could therefore be used to identify those most in need of nutritional support.
Serum vitamin E concentrations in adult-onset spinocerebellar degeneration.
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A comparison of the acute-phase response in middle aged and elderly patients.
The acute phase response in middle aged and elderly patients was compared by measuring the ratio of the peak C-reactive protein to peak creatine kinase level during the three day period after acute myocardial infarction. No difference in ratio was observed between a middle aged group of 14 patients (10.2 +/- 4.0 mean +/- s.e.), and an elderly group of 13 patients (9.1 +/- 1.5). C-reactive protein levels in two groups of middle aged and elderly control patients were similar (10.1 +/- 0.04 mg/l and 11.8 +/- 0.10 mg/l respectively). Production of C-reactive protein does not appear to be impaired in the elderly.
Plasma 25-hydroxyvitamin D concentration in patients with hip fracture in Hong Kong.
The serum concentration of 25-hydroxyvitamin D level and plasma albumin-adjusted calcium, phosphate, and alkaline phosphatase levels were studied in 200 patients with hip fracture (age range 49-93 years) and 427 elderly subjects living in the community (age range 60-90 years). The mean serum 25-hydroxyvitamin D levels in controls were higher than in temperate countries, but the 25-hydroxyvitamin D concentration was significantly lower in the patients than the controls for all sex and age groups. There was little difference in albumin-adjusted calcium and alkaline phosphatase levels, but the phosphate level was higher in the patients than in the controls. None of the patients with a low 25-hydroxyvitamin D level had a blood picture suggestive of osteopathy resulting from vitamin D deficiency or frank osteomalacia. Hip fracture patients with a low 25-hydroxyvitamin D level were much less ambulant and went outdoors much less frequently than hip fracture patients with a normal vitamin D level. A low vitamin D level was a risk factor for hip fracture in Hong Kong Chinese, and may be prevented by frequent outdoor exposure.
Diffusing capacity in healthy elderly Chinese.
Diffusing capacity (DLCO) was measured in 260 healthy subjects aged 60-86 years who were leading an active life in the community. DLCO correlated with body surface area and spirometric indices, and declined with age. It was lower in women, in smokers and in those with chronic bronchitis. Multiple regression equations based on age and body surface area were derived for elderly Chinese men and women. Compared with predicted values based on studies of Caucasians of all ages, those for elderly Chinese men were higher, while those for elderly women were similar. Predicted values for an elderly Chinese population should be derived from equations established from this survey rather than those extrapolated from Caucasians of all ages. DLCO/VA correlated with weight and body surface area but not with height, and declined with age. There was no difference between men and women, and between those with or without symptoms of chronic bronchitis. Predicted values from this study of elderly Chinese were comparable to those derived from Caucasians of all ages. Differences in DLCO values for elderly Chinese compared to Caucasians may be explained by differences in lung volumes rather than ethnic variations in the diffusing characteristics of the alveolar capillary membrane, and by the small numbers of elderly subjects in some of the studies of Caucasian subjects.
Epidemiologic study of Parkinson's disease in Hong Kong.
In our cross-sectional survey of the residents of homes for the elderly in 2 Hong Kong districts--Shatin and Tai Po--we found that 3.4% of the subjects had Parkinson's disease (PD). There was no sex difference in the disease rate. We also conducted a case-control study to determine the associated factors of PD. We found that subjects with residence of long duration in rural areas, with engagement in farming, with previous use of herbicides and pesticides, and with habitual consumption of raw vegetables had a statistically significantly increased risk of PD. This study tends to support the hypothesis that environmental factors directly or indirectly related to agricultural activities are associated with the development of PD.
Hematological indices and the prevalence of anemia in an elderly Chinese population.
Hematological indices were determined in a group of 427 elderly Chinese subjects over 60 years old; reference ranges were established after excluding subjects with hemoglobinopathies or diseases giving rise to anemia and those with values less or greater than 3 SD from the mean. The values were similar to those for elderly Caucasians. All the red cell indices were significantly higher in men than women, possibly reflecting the influence of androgens on bone marrow function. Previously reported age-related decline in hemoglobin, red cell count and hematocrit from studies of all age groups was not seen in men or women above age 60 years, but a fall in platelet count with age, which had not been previously reported, was observed. There were no age-related changes in any other indices. Reference ranges were lower for Hb, MCV, and MCH in men and women, compared to those derived from a study of Chinese of all age groups. The prevalence of anemia due to disease and hemoglobinpathies in this population was 6.4% in men and 6.3% in women.
Immunosuppressive activity, T-cell subset analysis, and acute toxicity of FK-506 in rats.
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Anti-schistosomal activity of cyclosporin A: studies on murine spleen cells and the influence of a cyclosporin antagonist on resistance to infection.
Mice were treated with 5-day courses of cyclosporin A (CsA) around the time of infection with Schistosoma mansoni. Recovery of lung-stage worms 4-8 days post-infection (p.i.) was substantially reduced (80%) and no sexually mature adults were recovered from the hepatic portal system at 7 weeks p.i. Flow cytometric analysis of spleen cells from CsA-treated animals during the period of maximal parasite attrition revealed transient reductions in CD3+ and CD4+ cells and in the CD4+: CD8+ ratio compared with drug vehicle-treated, infected controls. No significant numerical changes in B cells, macrophages or eosinophils were detected relative to vehicle-treated infected mice. Transfer of spleen cells from CsA-treated donors 8 days after infection failed to confer increased resistance to S. mansoni infection on untreated recipients. Moreover, concomitant administration of CsA and an inducer of interleukin-2 production (ADA-202-718) did not interfere with the anti-schistosomal effect of CsA. Despite our incomplete understanding of the in vivo properties of CsA and reports of its paradoxical effects on immune responses, these new data indicate that the influence of CsA in schistosomiasis is unlikely to be mediated by modulation of host cell mediated immunity. This contrasts with certain other anti-parasitic effects of CsA which appear to be mediated by an action on T cells.
Plasma ferritin in an elderly population living in the community.
Plasma ferritin was measured in 420 apparently healthy active elderly subjects living in the community. Mean values were comparable to other published results for elderly subjects. Higher values were obtained in men and in diabetic subjects. Mean values for men and women after exclusion of subjects with diabetes and other diseases were not significantly lower. It is concluded that a) the age-related rise in plasma ferritin observed in other studies represents a physiologic change, with pathologic processes only playing a small part in contributing to the increase, b) reference intervals appropriate to the elderly should be used, and c) plasma ferritin may not be a useful screening test for iron deficiency anemia or hemochromatosis in the elderly.
Some biochemical indices of bone turnover in elderly Chinese.
Biochemical indices of bone turnover were determined in a cluster sample of 427 apparently healthy elderly subjects aged 60 years and over. Plasma calcium concentrations corrected for albumin were not significantly different between elderly men and women, but were higher compared with values in younger Chinese of the same sex. The prevalence of hypercalcemia (greater than 2.75 mmol/L) in the elderly (0.2%) was lower than in Caucasian populations. Plasma phosphate concentrations were higher in women, but lower than in young adults. Plasma alkaline phosphatase activity was higher in women compared with values for men, and higher compared with values for young adults. Plasma 25-hydroxyvitamin D was lower in elderly women than elderly men, but was similar to values in younger subjects. Urinary calcium: creatinine and hydroxyproline: creatinine ratios were higher in women. The values were comparable to those for Caucasian postmenopausal women, suggesting that Chinese elderly subjects had similar bone turnover rates.
Nutritional status of healthy, active, Chinese elderly.
1. Anthropometric indices are presented for 402 healthy Chinese elderly subjects leading an active life in the community in Hong Kong. 2. Women had higher body-mass index (weight/height) and body fat, while fat-free mass, arm-muscle circumference and corrected arm-muscle area were higher in men. Body-mass index, fat-free mass, arm-muscle circumference and corrected arm-muscle area did not decline with age. Total body fat was lower in women aged 75 years and above compared with those aged 60-64 years. 3. All values were lower than those for elderly Caucasians. A different criteria for severe wasting malnutrition among elderly Chinese should be established.
Use of "average of normals" quality control procedure in the detection and resolution of assay discrepancies.
Improved computer technology and imperatives for cost control have made the use of "average of normals" (AVON) procedure an attractive alternative to the more expensive standard quality control programs for clinical laboratory assay monitoring. The authors report the use of a version of the AVON procedure to resolve assay discrepancies with CO2 determination that the traditional quality control program appeared incapable of detecting. Their study suggests that the mean of patients within the reference interval (RI) is a sensitive indicator of accuracy, whereas the percentage of patients within RI is a good indicator of random imprecision.
Adenomyosis uteri: a study of 416 cases.
Adenomyosis was noted in 16% of 2,616 consecutive hysterectomy specimens examined during a 7-year period. Multiparas between the ages of 30 and 50 years were most commonly affected. Abnormal uterine bleeding was the common symptom. Myohyperplasia and leiomyomas were the usual associated lesions. Adenomyosis uteri was seen equally in women of African, Indian and mixed races in this West Indian population.
Spirometry in healthy elderly Chinese.
Forced expiratory volume (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) were measured in healthy subjects (129 men, 210 women) aged 60 years and above who were leading an independent and active life in the community. Women but not men showed an age related decline in FEV1 and FVC. Correlations of FEV1 and FVC with height were weaker than those reported for all age groups. Male ex-smokers had lower FEV1 values than current smokers and non-smokers. Regression equations are derived for men and women for predicting values appropriate to Chinese elderly people. These values are slightly lower than those for white people, but the difference is not as great as in values derived from surveys of all age groups.