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Biomedical subjects

C S Lau

Publications and source records attributed to C S Lau.

At least 19 recordsLinked to original sources
PubMed2007

Ganoderma lucidum polysaccharide peptide reduced the production of proinflammatory cytokines in activated rheumatoid synovial fibroblast.

The aim of the current study was to elucidate the potential therapeutic effect of Ganoderma lucidum polysaccharide peptide (GL-PP) in rheumatoid arthritis (RA). The effects of GL-PP on cell proliferation and cytokine production were studied in RA synovial fibroblasts (RASF). GL-PP significantly inhibited the proliferation of RASF. Following the incubation with GL-PP, production of interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1 in RASF were significantly increased as expressed as percentage change from basal values. However, the actual effects were minimal due to the low basal values. When RASF were activated by IL-1beta or lipopolysaccharides, IL-8 and MCP-1 production increased many folds. GL-PP significantly suppressed their productions. The inhibitory effects of GL-PP on cytokine production in RASF were at least in part, by inhibiting the nuclear factor-kappa B (NF-kappaB) transcription pathway. Our results demonstrated that GL-PP had the unique ability to modulate cytokine production in RASF and warrants further investigation into its mechanism of action.

Arthritis, Rheumatoid↗
PubMed2006

Non-tuberculous mycobacterial infection in patients with systemic lupus erythematosus.

OBJECTIVES: Patients with systemic lupus erythematosus (SLE) are susceptible to opportunistic infections. To examine the clinical manifestations of non-tuberculous mycobacterial (NTM) infections with those of Mycobacterium tuberculosis (MTB) infections in SLE patients. METHODS: Medical records of a cohort of 725 SLE patients were reviewed for previous NTM infections. Demographic characteristics, predisposing factors and clinical outcomes were compared with patients who had previous MTB infections (n = 39). RESULTS: Eleven (nine female and two male) cases were identified (prevalence 1.5%). The mean +/- S.D. age at the time of infection was 42.8 +/- 13.9 yrs, 9.3 +/- 5.8 yrs after the onset of SLE. The mean +/- S.D. time taken from onset of symptoms to the diagnosis of NTM infection was 5.7 +/- 7.2 months. Sites of involvement included skin and soft tissue (n = 8), chest (n = 2) and disseminated infection (n = 1). NTM infections were more likely to involve extrapulmonary sites (P = 0.006), presented in patients with longer lupus disease duration (P < 0.001), occurred in older patients (P < 0.001) and in those who had a higher cumulative dose of prednisolone (P = 0.01) than MTB infections. Using a stepwise logistic regression, disease duration was found to be the only independent predictive factor (P = 0.005) for NTM infections. Ten (25.6%) patients with MTB infections but none of the patients with NTM infections presented concomitantly at the onset of SLE (P = 0.09). There were no differences in the recurrence rate (P = 0.64) and frequency of disseminated infections (P = 0.40) between NTM and MTB infections. CONCLUSIONS: NTM infections tended to develop in SLE patients later in their disease course than MTB infections. A high index of suspicion is required for its diagnosis.

Adult↗
PubMed2006

Report on the second Asia Autoimmunity Forum 3-5 March 2006, Hong Kong.

On March 3-5, 2006, The HK Society of Rheumatology, University of Hong Kong and Singapore National Arthritis Foundation organized the second Asia Autoimmunity Forum (AAF) in Hong Kong which was attended by over 200 delegates from around Asia. More than 20 invited international and regional experts in the field of autoimmune rheumatic diseases spoke on topics including the pathogenetic mechanisms, clinical aspects and novel therapeutic approaches of autoimmune rheumatic diseases. There were 8 plenary lectures and 4 symposia and the AAF provided an excellent avenue to promote the co-ordination and knowledge exchange in the area of autoimmune rheumatic diseases in Asia.

Animals↗
PubMed2006

Adrenomedullin--a potential disease activity marker and suppressor of nephritis activity in systemic lupus erythematosus.

OBJECTIVES: To investigate whether plasma adrenomedullin (AM) level is elevated in lupus nephritis and to examine if plasma AM level is correlated with systemic lupus erythematosus (SLE) disease activity and severity of lupus nephritis after multivariate adjustment. METHODS: Consecutive SLE patients and healthy volunteers of age >/=16 were recruited from the rheumatology clinics of two hospitals in Hong Kong. SLE patients with nephritis fulfilled the American College of Rheumatology criteria for renal involvement and had percutaneous renal biopsy performed. Subjects were divided into three groups: (i) SLE patients with nephritis, (ii) SLE patients without nephritis and (iii) normal controls. The demographic and clinical variables were compared between these groups of patients and plasma AM level was determined by radioimmunoassay. Factors associated with plasma AM level were explored by regression analysis with adjustment of confounding factors. RESULTS: Sixty SLE patients (39 with nephritis and 21 without) and 23 normal subjects were studied. The plasma AM level of SLE patients was significantly higher than that of normal controls. SLE patients with nephritis had significantly higher plasma AM level than those without nephritis and normal controls (P<0.001). In regression analysis, proteinuria was negatively associated with plasma AM level (P=0.006) whereas SLE disease activity index was positively associated with plasma AM level after multivariate adjustment (P=0.002). CONCLUSIONS: Plasma AM is elevated in lupus nephritis, which correlates with lupus disease activity. It is negatively associated with urine protein excretion although it is unrelated to the type of renal pathology per se. Plasma AM may play a role to suppress the activity of lupus nephritis.

Adrenomedullin↗
PubMed2006

Ethnic and geographical differences in systemic lupus erythematosus: an overview.

Systemic lupus erythematosus (SLE) is one of the most heterogeneous autoimmune disorders known. There is production of a variety of autoantibodies and patients present with a wide range of symptoms due to multiple organ involvement by the disease process. The underlying cause is not fully understood but it may involve genetic and environmental factors. It is interesting to note that while SLE is found worldwide, it is more commonly found in some countries, and within a country certain ethnic groups appear to be more susceptible to develop this condition than others. Additionally, the presentation and course of SLE appear highly variable between patients of different ethnic origins. For example, African-Americans and Orientals are believed to have a more severe disease than Caucasian whites. But are these ethnic and geographical differences real? If yes, they may provide investigators insight into the underlying pathoaetiology of this condition and pave the way to future research directions in lupus.

Anemia, Hemolytic, Autoimmune↗
PubMed2006

Necrotizing fasciitis in rheumatic diseases.

Necrotizing fasciitis is an uncommon but life-threatening complication in immunocompromised hosts. We reported four patients with rheumatic diseases complicated by necrotizing fasciitis and reviewed 14 others from literature search. Most patients were on corticosteroid treatment. Septic shock, disseminated intravascular coagulopathy and acute renal deterioration were common giving rise to an overall mortality rate of 27.8%. Septic arthritis may also complicate the condition. Statistical analysis on the series showed the lack of major surgical debridement as the only risk factor associated with increased mortality (RR 7.5, 95% CI 2.1-27.3, P = 0.01). Timely debridement of necrotic tissue is important for reducing mortality.

Adult↗
PubMed2005

Effects of prenatal perfluorooctane sulfonate (PFOS) exposure on lung maturation in the perinatal rat.

BACKGROUND: Perfluorooctane sulfonate (PFOS), found widely in wildlife and humans, is environmentally and metabolically stable. Environmental PFOS may be from its use as a surfactant, hydrolysis of perfluorooctanesulfonyl fluoride, and degradation of N-alkyl-perfluorooctanesulfonamide compounds formerly used in numerous applications. Prenatal exposure to PFOS in rodents causes neonatal mortality; treatment on gestation days (GD) 19-20 is sufficient to induce neonatal death in rats. Affected pups are born alive but present with labored breathing. Their lungs are pale and often do not expand fully on perfusion. METHODS: Pregnant Sprague-Dawley rats received 0, 25, or 50 mg/kg/day PFOS/K+ orally on GD 19-20. Lungs from GD 21 fetuses and neonates were prepared for histology and morphometry. Rescue experiments included co-administration of dexamethasone or retinyl palmitate with PFOS. Pulmonary surfactant was investigated with mass spectrometry in GD 21 amniotic fluid and neonatal lungs. Microarray analysis was carried out on PND 0 lungs. RESULTS: Histologically, alveolar walls were thicker in lungs of PFOS-exposed newborns compared to controls. The ratio of solid tissue:small airway was increased, suggesting immaturity. Rescue studies were ineffective. Phospholipid concentrations and molecular speciation were unaffected by PFOS. No changes in markers of alveolar differentiation were detected by microarray analysis. CONCLUSIONS: Morphometric changes in lungs of PFOS exposed neonates were suggestive of immaturity, but the failure of rescue agents and normal pulmonary surfactant profile indicate that the labored respiration and mortality observed in PFOS-treated neonates was not due to lung immaturity.

Alkanesulfonic Acids↗
PubMed2004

Translation and validation of Arthritis Impact Measurement Scales 2 into Chinese: CAIMS2.

OBJECTIVE: To evaluate the validity, reliability, and cultural relevance of the Arthritis Impact Measurement Scales 2 (AIMS2) as a health assessment tool for Chinese-speaking patients with arthritis. METHODS: The cultural relevance, language equivalency, and content validity of the AIMS2, Chinese version (CAIMS2) were evaluated by an expert panel. Measurement performance was tested on 240 subjects (rheumatoid arthritis = 81, osteoarthritis = 77, healthy = 82). Subjects (n = 175) were retested within 2 weeks for testing of reliability. RESULTS: Three items were modified and 2 items were added, as suggested by the expert panel. Interitem reliability was satisfactory (intraclass correlation coefficient 0.8552-0.9594). Test-retest reliability of the CAIMS2 subscales ranged from 0.770 to 0.952 in subjects in whom the CAIMS2 was self administered. Significant score differences between patients with arthritis and healthy subjects were found in all 12 subscales, except for the support from family and friends and tension subscales. CAIMS2 subscale scores correlated with clinical and laboratory measures of disease activity and patients' perceived quality of life as measured using the Chinese version of the World Health Organization Quality of Life instrument. CONCLUSION: Empirical data support CAIMS2 is a valid and reliable health status measure for Chinese speaking patients with arthritis.

Activities of Daily Living↗
PubMed2004

In vitro study of regulation of IL-6 production in bronchiectasis.

Persistent airway inflammation is an important pathogenetic factor in bronchiectasis, and interleukin (IL)-6 is among the mediators implicated in regulation of inflammation in bronchiectatic airways. We postulated that airway secretion with its constituents of cytokines and enzymes would provide an environment for perpetuation of inflammation in vivo. We aimed to determine the action of sputum from patients with bronchiectasis on IL-6 production from cultured normal human bronchial epithelial (NHBE) cells and its modulation by anti-inflammatory drugs in vitro. Cultures of NHBE cells were tested with (i) sputum of bronchiectatic patients, (ii) anti-tumor necrosis factor-alpha (TNF-alpha) pre-treated sputum, or (iii) recombinant human (rh)-TNF-alpha. Alternatively, NHBE cells were incubated with one of the anti-inflammatory drugs before treatment with sputum or rh-TNF-alpha. IL-6 produced into the medium was assayed by ELISA. Sputum in bronchiectasis stimulated IL-6 production from NHBE cells by 1.9 times. This was largely attributable to TNF-alpha as pre-incubation of sputum sol with anti-TNF-alpha almost neutralized the sputum effect. Apart from dexamethasone, the other drugs exerted inhibitory effects on IL-6 production. Ibuprofen suppressed sputum-stimulated IL-6 production to levels above control and effect levelled off at 50-100 microg/mi, contrasting the dose-dependent suppression to control level with MK-663 (0.1-10 microg/ml) and to sub-control levels with triptolide (20-1000 ng/ml). Our results support that sputum in bronchiectasis can stimulate IL-6 production from NHBE cells, and TNF-alpha is an important cytokine mediating the process. The suppressive effects observed with ibuprofen, triptolide and MK-663 warrant further study.

Anti-Inflammatory Agents↗
PubMed2004

Association of interleukin-10 promoter polymorphisms with systemic lupus erythematosus.

Several lines of evidence suggest interleukin-10 gene (IL-10) is a candidate gene in susceptibility to systemic lupus erythematosus (SLE). We investigated the association of IL-10 promoter single-nucleotide polymorphisms (SNPs) (-3575T/A, -2849G/A, -2763C/A, -1082A/G, -819T/C and -592A/C) and microsatellites (IL10.R, IL10.G) with SLE in 554 Hong Kong Chinese patients and 708 ethnically matched controls. Six haplotypes (hts) were identified from the SNPs. The genotype distribution of the ht1 (T-C-A-T-A), which is associated with low IL-10 production, was different in patients and controls (P=0.009). The homozygous genotype of non-ht1 was significantly increased in patients (P=0.009, odds ratio (OR)=1.80, 95% CI: 1.15-2.82). The frequency of IL10.G4 of IL10.G was also significantly increased in patients (P=0.017, OR=2.53, 95% CI: 1.18-5.40). We found that the homozygous non-ht1 combined with short allele (CA repeat number < or =21) of IL10.G has a dose-dependent effect on SLE susceptibility: non-ht1/non-ht1 with homozygous short allele showed a higher OR (OR=4.11, 95% CI: 1.27-13.2, P=0.018) of association with SLE than the genotype of non-ht1/non-ht1 with heterozygous short/long allele (OR=2.98, 95% CI: 1.26-7.07, P=0.013) and homozygous long allele (OR=1.05, 95% CI: 0.62-1.78, P=0.848). The frequency of non-ht1 was significantly increased in patients with serositis (P<0.0001, OR=2.42, 95% CI: 1.55-3.80). In conclusion, the high expression promoter genotype is associated with SLE in Chinese.

Adult↗
PubMed2004

Impact of Sjögren's syndrome on oral health-related quality of life in southern Chinese.

The effect of oral symptoms of Sjögren's syndrome (SS) on health-related quality of life is presently uncertain. This study aimed to investigate oral health-related quality of life (OHRQOL) among southern Chinese people with SS. Twenty-six primary SS cases, 25 secondary cases and 29 matched controls took part in this cross-sectional study. Each participant completed a SF-36 questionnaire, the Oral Health Impact Profile and a dry mouth measure, assisted by a trained interviewer. Data on socio-demographic variables were also collected. The dry mouth measure revealed that people with primary and secondary SS had significant problems associated with subjective symptoms of dry mouth generally, and dry mouth when eating and speaking (P < 0.01). Sticky saliva and coughing were also problems in some primary SS cases. OHIP summary and sub-scale scores did not reveal differences in negative impacts between groups. Mean SF-36 sub-scale scores were significantly different between groups (P < 0.05). In physical function, role-physical and general health domains, primary and secondary SS sufferers had lower scores indicating poorer health. Oral symptoms of SS, notably xerostomia, had a negative effect on OHRQOL. Health-related quality of life in general was also impaired in SS sufferers. The OHIP did not appear to discriminate oral problems of concern to SS sufferers.

Adult↗
PubMed2004

Antibodies to mannose binding lectin in patients with systemic lupus erythematosus.

Deficiency of mannose binding lectin (MBL), a C-type lectin with structural similarities to C1q, has been shown to predispose to the development of systemic lupus erythematosus (SLE). Some patients have low serum MBL levels which cannot be explained by either structural gene mutations or promoter polymorphisms. The objective of this study was to detect the presence of autoantibodies against MBL and to evaluate their relationship to serum MBL levels. Anti-MBL antibodies of IgM and IgG classes from consecutive SLE patients (n = 135) and healthy subjects (n = 50) were measured by an in-house ELISA. Using the 90th percentile of controls as a cutoff, more SLE patients [23.7% (32/135)] were found to have IgG anti-MBL antibodies than normal controls [10.0% (5/50)] (P = 0.04). The same trend was observed when ethnicity was taken into account by analysing Caucasians alone (n = 90). IgM anti-MBL antibodies were only found in two SLE patients (2/22, 9.1%) who had no concomitant IgG anti-MBL antibodies. Serum levels of IgG anti-MBL antibodies were found to correlate with serum MBL levels (r = 0.55, P = 0.049). However, the levels of anti-MBL antibodies did not correlate with overall disease activity. Thus the production of anti-MBL antibodies is likely to be a specific antigen-driven process. Its role in lupus pathogenesis remains to be elucidated.

Adult↗
PubMed2003

Effect of treatment of Helicobacter pylori on the prevention of gastroduodenal ulcers in patients receiving long-term NSAIDs: a double-blind, placebo-controlled trial.

BACKGROUND: There is controversy as to whether Helicobacter pylori and non-steroidal anti-inflammatory drugs interact to cause peptic ulcers. AIM: To study whether the eradication of H. pylori in patients on long-term non-steroidal anti-inflammatory drug therapy prevents the development of ulcers. METHODS: Patients infected with H. pylori whilst receiving long-term non-steroidal anti-inflammatory drug therapy, but with no ulcers at baseline endoscopy, were randomized to receive either triple antibiotic therapy (metronidazole 300 mg, clarithromycin 250 mg and amoxicillin 500 mg, given four times daily; n = 70) or placebo (n = 70) for 2 weeks. Non-steroidal anti-inflammatory drugs were continued throughout the study period. Endoscopy was repeated 12 weeks after the end of treatment. The development of ulcers was compared between the two groups. RESULTS: Endoscopy at 12 weeks revealed peptic ulcer development in five [7%; 95% confidence interval (CI), 2-16] of the patients who received triple therapy and in six (9%; 95% CI, 3-18) of those who received placebo (P = 1.00). No significant difference in the development of ulcers was found between patients with persistent H. pylori infection (7/80; 9%; 95% CI, 4-17) and those with the eradication of H. pylori (4/52; 8%; 95% CI, 2-19) (P = 1.00). CONCLUSIONS: The eradication of H. pylori in patients receiving long-term treatment with non-steroidal anti-inflammatory drugs did not prevent ulcer development. However, because the rate of ulcer development was low, a study with a larger sample size is required to confirm this finding.

Adolescent↗