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Biomedical subjects

C W Lam

Publications and source records attributed to C W Lam.

At least 73 records · Page 4Linked to original sources
PubMed2000

Dialysate hyaluronan concentration predicts survival but not peritoneal sclerosis in continuous ambulatory peritoneal dialysis.

Hyaluronan is an important component of extracellular matrix and plays a critical role in early phases of wound healing. Peritoneal mesothelium is a major site of hyaluronan production. Serum hyaluronan concentration has been shown to predict survival in maintenance hemodialysis patients. We hypothesize that mesothelial production of hyaluronan during the stable phase of continuous ambulatory peritoneal dialysis (CAPD) predicts the risk of peritoneal adhesion and mortality. We studied peritoneal dialysate effluent (PDE) hyaluronan levels from 116 stable CAPD patients. They were then followed-up for 3 years. During the follow-up period, there were 196 episodes of peritonitis in 78 patients. Tenckhoff catheter was removed in 31 episodes (15.8%). Tenckhoff catheter was reinserted successfully in 12 cases, and CAPD was resumed. Peritoneal adhesion developed in 16 cases. Three patients died before Tenckhoff catheter reinsertion was attempted. There was no difference in stable-phase PDE hyaluronan levels between patients who developed peritoneal adhesion and those who did not (159 +/- 63 versus 227 +/- 194 microgram/L, P = 0.27). Thirty-three patients died during the study period. Patients who died had significantly higher PDE hyaluronan concentration than survivors (272 +/- 194 versus 170 +/- 105 microgram/L, P < 0.01). Univariate analysis showed that increased PDE hyaluronan level was associated with a shorter patient survival (P < 0.001). There was no association between PDE hyaluronan level and serum albumin, protein nitrogen appearance, and percentage of lean body mass. Multivariate analysis confirmed that PDE hyaluronan level, serum albumin, and diabetic state were independent predictors of survival. We conclude that PDE hyaluronan level during stable phase of CAPD does not predict the risk of postperitonitis adhesion. However, it is a strong independent predictor of survival in CAPD patients.

Analysis of Variance↗
PubMed2000

Fat intake in Hong Kong Chinese children.

The people of Hong Kong are experiencing a transition in dietary practices and lifestyle that can be observed in the fat intakes of Hong Kong children as compared with those of their counterparts on mainland China. The studies described here include 1) a longitudinal and observational dietary survey beginning with a cohort of 174 newborns and concluding with 124 children at age 7 y; 2) a biochemical study of serum lipids in relation to dietary fat intake at age 7 y; 3) a chemical fatty acid analysis and comparison of duplicate meals collected from 20 Hong Kong and 20 mainland Chinese children at age 7 y; 4) a dietary assessment of 52 lactoovovegetarian children aged 4-14 y; and 5) a comparison of the growth of all subjects with US National Center for Health Statistics standards. About 30% of the total daily energy intake of Hong Kong Chinese children aged 1-7 y was contributed by fat-much more than that in the traditional Chinese diet. Growth of the children was not impaired, including that of children on the mainland and of those lactoovovegetarians in Hong Kong whose fat intakes were lower. Mean serum cholesterol of Hong Kong Chinese children at age 7 y was 4.59 mmol/L, significantly higher than that of their counterparts on the mainland, 4.16 mmol/L. Foods consumed in Hong Kong had a significantly lower ratio of 18:2 to 14:0. Nutritional deficiency was uncommon. Chinese children in Hong Kong had a dietary fat intake that was both quantitatively and qualitatively different from the traditional Chinese diet.

Adolescent↗
PubMed2000

Analysis of mid-trimester corticotrophin-releasing hormone and alpha-fetoprotein concentrations for predicting pre-eclampsia.

The aims of this study were firstly to examine if corticotrophin-releasing hormone (CRH) concentrations in maternal plasma were significantly elevated in Chinese pregnancies complicated by pre-eclampsia, secondly to assess if this elevation could be detected in the mid-trimester before onset of clinical signs of the disease, and thirdly to evaluate the performance of using maternal CRH and/or alpha-fetoprotein (AFP) concentrations in the mid-trimester for prediction of pre-eclampsia. The first part of this study was tested in a cohort of 39 subjects. The CRH concentrations were significantly elevated in pregnant women complicated by pre-eclampsia. The second and third parts of the study involved a different cohort of 1021 subjects. Both CRH and AFP concentrations in the mid-trimester were significantly elevated in those who subsequently developed pre-eclampsia. However, when used for prediction of pre-eclampsia, neither the CRH nor AFP concentrations alone in the mid-trimester had strong predictive value. Although the combination of both tests improved the detection rate compared to the use of CRH alone, the small increase in the likelihood ratio from 1.9 to 2.6 did not suggest that the combination would be of great clinical value.

Adult↗
PubMed2000

A multicentre study of the early bactericidal activity of anti-tuberculosis drugs.

The early bactericidal activities (EBAs) of 300 mg isoniazid, 18.5 mg isoniazid, 600 mg rifampicin and 800 mg ofloxacin given daily to 262 patients with newly diagnosed pulmonary tuberculosis in Cape Town, Nairobi, Madras and Hong Kong were measured by counting cfu and total acid-fast bacilli in sputum collections taken pre-treatment (S1), at 2 days (S3) and at 5 days (S6). In Cape Town, Nairobi and Madras, the cfu findings suggested that isoniazid produced a massive kill, perhaps of actively growing organisms, during the first 2 days (mean S1-S3 EBAs of 0.636-1.006) but was almost inactive thereafter (mean S3-S6 EBAs of 0.000-0.081), whereas rifampicin maintained moderate activity against slowly growing organisms throughout the 5 days (mean S3-S6 EBAs of 0.242-0.305). This finding suggests that EBAs measured during the 2-5 day interval might be able to assess the sterilizing activity of drugs. Ofloxacin had moderately high mean S1-S3 EBAs of 0.130-0.391. However, in Hong Kong rifampicin appeared to be the most bactericidal drug from the start, possibly because patients had more chronic disease. A method of adjusting the cfu EBAs using total counts was devised which decreased the variability between patients within a treatment group without altering the mean cfu EBA. This resulted in a large gain in precision in Hong Kong, suggesting that their estimates were greatly affected by type II variation, due to dilution of pus by saliva and bronchial secretions, whereas small or no gains were obtained in the other three centres, suggesting that the main cause of variability was type I, due to other factors.

Adult↗
PubMed2000

Elevation of plasma interleukin-18 concentration is correlated with disease activity in systemic lupus erythematosus.

BACKGROUND: Previous studies have indicated that the autoimmune phenomenon might be caused by an imbalance of T-helper cell (Th) cytokines. METHODS: We investigated the plasma concentrations of a novel pro-inflammatory Th1 cytokine, interleukin (IL)-18, and its inducer, IL-12, in patients with systemic lupus erythematosus (SLE) and correlated them with the SLE disease activity index (SLEDAI). Plasma IL-18 and IL-12 concentrations of 40 SLE patients and 18 sex- and age-matched control subjects were measured by enzyme-linked immunosorbent assay. RESULTS: Plasma IL-18 and IL-12 concentrations were significantly higher in SLE patients than in control subjects [median (interquartile range): IL-18, 320.0 pg/ml (164.4-475.6 pg/ml) vs 130.1 pg/ml (57.8-202.4 pg/ml), P<0.001; IL-12, 143.3 pg/ml (39.4-247.2 pg/ml) vs. 84.7 pg/ml (29.3-140.1 pg/ml), P<0.001]. Increases in IL-18 concentration correlated positively and significantly with SLEDAI score (r = 0.449, P = 0.004). CONCLUSION: The novel cytokine IL-18 might play a crucial role in triggering the inflammatory processes in SLE.

Adolescent↗
PubMed2000

Mercury intoxication presenting with tics.

A 5 year old Chinese boy presented with recurrent oral ulceration followed by motor and vocal tics. The Chinese herbal spray he used for his mouth ulcers was found to have a high mercury content. His blood mercury concentration was raised. Isolated tics as the sole presentation of mercury intoxication has not previously been reported.

Child, Preschool↗
PubMed2000

Leptin and metabolic hormones in infants of diabetic mothers.

AIMS: To investigate the effect of maternal diabetes on leptin in term newborns and to determine whether leptin correlates with insulin and its associated biochemical parameters in support of the hypothesis that a functional "adipoinsular axis" might exist at this stage of development. METHODS: A total of 116 term newborns were prospectively enrolled and categorised into three groups: 44 were infants of non-diabetic mothers (control group C); 41 were infants born to mothers with gestational diabetes on dietary treatment (group D); and 31 were infants born to mothers with gestational or pregestational diabetes on insulin treatment (group I). RESULTS: No significant difference in serum leptin was observed between the three groups; the results of the study population were therefore pooled and analysed. Serum leptin correlated significantly with serum insulin, insulin:glucose ratio, birth weight, body length, body mass index, placenta weight, and maternal HbA(1c). Female infants had significantly higher serum leptin than male infants. All parameters except placenta weight and body length remained significantly associated with serum leptin when multivariate stepwise regression analysis was applied. Subgroup analysis revealed a significant correlation between serum leptin and cortisol in group D. CONCLUSIONS: There was no significant difference in serum leptin between infants born to diabetic and non-diabetic mothers, though infants born to mothers requiring insulin treatment had the highest median serum leptin concentrations. The significant association between serum leptin and insulin or insulin:glucose ratio supports the hypothesis that a functional adipoinsular axis might exist in term newborns. Furthermore, the significant correlation between maternal HbA(1c) and circulating leptin of the studied infants suggests that the clinical control of maternal diabetes could affect the regulation of serum leptin in these infants.

Blood Glucose↗
PubMed2000

Leptin and metabolic hormones in preterm newborns.

AIM: To investigate the inter-relation between leptin and other metabolic hormones in preterm and term infants and to explore whether a functional "adipoinsular axis" might exist in preterm newborns. METHODS: A total of 140 preterm and term newborns were prospectively recruited and categorised according to gestation length. Blood samples were taken at 24 hours (day 1), and on day 4-5 of life. RESULTS: Serum leptin, cortisol, free thyroxine, and plasma ACTH on day 1 were significantly higher in term than in preterm infants. The relation between serum leptin and gestation followed a non-linear pattern; the slope of the curve began to increase steeply between 33 and 35 weeks gestation. Serum leptin on day 1 was significantly associated with serum insulin, insulin:glucose ratio, and plasma ACTH in infants less than 34 weeks gestation; serum leptin on day 1 and day 4-5 were significantly correlated with insulin:glucose ratio in infants 34 or more weeks gestation. Significant changes in the pattern of metabolic hormones were observed in the first week of life. Serum insulin and plasma glucose were significantly increased between day 1 and day 4-5; serum leptin was significantly decreased. CONCLUSIONS: The circulating leptin concentration increases markedly after 34 weeks gestation and bears a close temporal relation with the exponential accumulation of body fat mass during that period. The inter-relation between serum leptin and insulin or insulin:glucose ratio before and after 34 weeks gestation indicates that the "adipoinsular axis" is likely to be functional in early (<34 weeks gestation) intrauterine life. The rapid decline in the circulating concentrations of leptin after birth may be of physiological advantage to preterm and term newborns by limiting their body energy expenditure and conserving nutritional reverses for subsequent growth and development.

Adrenocorticotropic Hormone↗
PubMed2000

Sodium salicylate-induced apoptosis of human peripheral blood eosinophils is independent of the activation of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase.

BACKGROUND: It has been shown that the inhibition of eosinophilic apoptosis is an important mechanism for the development of blood and tissue eosinophilia in allergic diseases. Considerable attention has recently been focused on the role played by different intracellular kinase cascades in the control of apoptosis. In the present study, we investigated the effect of sodium salicylate (NaSal), a nonsteroidal anti-inflammatory drug, on mitogen-activated protein kinases (MAPK) and apoptosis of human eosinophils. METHODS: Human blood eosinophils were purified from buffy coat. NaSal-induced apoptosis of eosinophils was assessed by morphological changes and Annexin-V binding assay. Changes of MAPK activity upon treatment with NaSal were measured by kinase activity assay and Western blot. RESULTS: NaSal could induce apoptosis of human blood eosinophils in a dose- and time-dependent manner. It could also activate c-Jun N-terminal kinase (JNK) and p38 MAPK but not extracellular signal-regulated protein kinase (ERK) activity within 1 h. Pretreatment of eosinophils with p38 MAPK and JNK anti-sense (AS) phosphorothioate oligodeoxynucleotides (ODN) or specific p38 MAPK inhibitor SB 203580 did not have any significant effect on NaSal-induced apoptosis. However, ERK AS ODNs could trigger the apoptosis of normal eosinophils. CONCLUSION: There is no direct relationship between the activation of JNK and p38 MAPK pathways and NaSal-induced apoptosis in human peripheral blood eosinophils.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2000

Hydroxychloroquine has no significant effect on lipids and apolipoproteins in Chinese systemic lupus erythematosus patients with mild or inactive disease.

OBJECTIVE: To investigate the effects of hydroxychloroquine (HCQ) in Chinese patients with systemic lupus erythematosus who were either on a low dose of prednisone or not on prednisone. METHODS: 65 consecutive Chinese lupus patients without features of nephritis underwent assessment of the fasting serum lipid profile, including total cholesterol (TC), triglycerides (TG), HDL-cholesteorl (HDL-C), LDL-cholesterol (LDL-C), apolipoprotein A-1 (apo A-1), apolipoprotein B (apo B) and lipoprotein (a) (Lp(a)). RESULTS: 44/65 (67.7%) patients were on HCQ with a dose of 244 +/- 86 mg daily and 34/65 (52.3%) patients were on 4.3 +/- 2.6 mg daily of prednisone. The percentages of patients taking prednisone and the mean dose in those patients receiving this treatment were not different between the groups with or without HCQ treatment. TG tended to be lower in those patients on HCQ (median and interquartile range) (1.0 (0.7-1.4) mmol/L vs 1.2 (0.8 1.6) mmol/L), but there were no significant differences in TC or other lipid parameters including Lp(a) between the 2 groups of patients with or without HCQ treatment. CONCLUSION: HCQ had no significant effect on the serum lipid profile in these lupus patients with mild or inactive disease. This finding probably reflects the low doses of corticosteroid used and a lower background lipid level in this population.

Adult↗
PubMed2000

Elevation of proinflammatory cytokine (IL-18, IL-17, IL-12) and Th2 cytokine (IL-4) concentrations in patients with systemic lupus erythematosus.

Previous studies have indicated that the autoimmune phenomenon might be caused by an imbalance of T helper cell (Th) cytokines. We measured the plasma concentrations of three novel proinflammatory cytokines interleukin (IL)-17, IL-18, IL-12 and a key Th2 cytokine IL-4 in patients with systemic lupus erythematosus (SLE) and correlated the ratio of proinflammatory/Th2 cytokines with SLE disease activity index (SLEDAI). Plasma IL-12, IL-17, IL-18 and IL-4 concentrations of 36 SLE patients and 18 sex- and age-matched control subjects were measured by enzyme linked immunosorbent assay. All were significantly higher in SLE patients than control subjects (IL-12, mean+/-s.d. of 166.7+/-84.5 vs 93.5+/-39.2 pg/ml, P<0.001; IL-17, 76.5+/-45.7 vs 37.6+/-35.3 pg/ml, P=0.002; IL-18, 368.7+/-199. 5 vs 141.1+/-47.1 pg/ml, P<0.001; and IL-4, 27.1+/-15.3 vs 17.3+/-7. 2 pg/ml, P<0.05), and IL-18/IL-4 ratio correlated positively and significantly with SLEDAI score (r=0.435, P=0.006). We propose that SLE is characterized by an elevation of both Th1 and Th2 cytokines: the elevation of proinflammatory cytokine IL-12, IL-17 and IL-18 may trigger the inflammatory process in SLE and the elevation of IL-18/IL-4 ratio suggests an imbalance of cytokine profile to mediate the inflammatory response.

Adolescent↗
PubMed2000

Alpha-fetoprotein variants in a case of pancreatoblastoma.

We describe a 6-year-old boy with histologically confirmed pancreatoblastoma and a markedly elevated serum alpha-fetoprotein (AFP) concentration. Due to local tumour invasion, cytotoxic chemotherapy was given to debulk the tumour before attempting surgical resection. Serial serum AFP concentrations were measured on this patient. During chemotherapy there was a > 95% fall in total AFP. Tumour-specific variants of AFP, detected by isoelectric focusing, also disappeared during chemotherapy but recurred when chemotherapy was withdrawn. It is suggested that although there was no change in overall size of the tumour, as assessed by various imaging techniques, the changes in serological markers may indicate that the treatment did in fact cause considerable tumour necrosis, AFP and its variants may be useful markers of tumour response in patients with pancreatoblastoma. The expression of AFP and its variants in pancreatoblastoma may be related to the embryonic origin of the pancreas.

Antineoplastic Agents↗
PubMed1999

Differentiation of a human eosinophilic leukemic cell line, EoL-1: characterization by the expression of cytokine receptors, adhesion molecules, CD95 and eosinophilic cationic protein (ECP).

Purification of enough eosinophils for the study of allergic inflammation is difficult because eosinophils comprise only a small percentage of circulating leucocytes. A human eosinophilic leukemic cell line, EoL-1, has been considered to be an in vitro eosinophilic model. In the present study, the suitability of EoL-1 cells as an eosinophilic model was further investigated. EoL-1 cells were induced to differentiate by dibutyryl cyclic AMP (dbcAMP). The expression of cell surface cytokines (IL-3, IL-5, GM-CSF) receptors, adhesion molecules (CD49d, CD11b), and CD95 (Fas) was investigated by flow cytometry. Expression of eosinophilic cationic protein (ECP) was determined by fluorescence enzyme immunoassay (FEIA) and reverse transcription-polymerase chain reaction (RT-PCR). EoL-1 cells could be differentiated into eosinophilic vacuole-containing cells by dbcAMP. They were found to express cell surface IL-3 and GM-CSF receptors, CD95 and CD49d. Treatment with dbcAMP could induce the expression of CD11b but decrease the expression of CD95. Anti-CD95 antibody could induce their apoptosis. The differentiation of EoL-1 cells was accompanied by increase in release of ECP into the supernatant and total ECP synthesis. Differentiation of EoL-1 cells also up-regulated the expression of mRNA for ECP and its level was parallel to the total amount of ECP synthesis. By virtue of their expression of haematopoietic cytokines receptors, adhesion molecules, CD95, synthesis and release of ECP, EoL-1 cells are suitable as an in vitro eosinophilic model for studying eosinophilic functions.

Antigens, CD↗