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Biomedical subjects

S K Chow

Publications and source records attributed to S K Chow.

At least 19 recordsLinked to original sources
PubMed2006

Dietary calcium and bone mineral density in premenopausal women with systemic lupus erythematosus.

The primary objective of this study was to determine the relationship between dietary calcium intake and bone mineral density (BMD) in premenopausal women with systemic lupus erythematosus (SLE) on corticosteroids (CS). The secondary aim was to identify other risk factors for osteoporosis in these patients. A cross-sectional sample of patients attending the SLE Clinic at a teaching hospital was recruited. BMD was measured using dual-energy X-ray absorptiometry. Daily dietary calcium intake was assessed using a structured validated food frequency questionnaire, in which patients were asked to estimate their food intake based on their recent 2-month dietary habits. Sixty subjects were recruited with a mean age of 33.70+/-8.46 years. The median duration of CS use was 5.5 years (range 0.08-24). The median cumulative dose of steroids was 17.21 g (range 0.16-91.37). The median daily dietary calcium intake was 483 mg (range 78-2101). There was no significant correlation between calcium intake and BMD, even after correcting for CS use. There were also no correlations between BMD and the duration of SLE, cumulative CS use, duration of CS use, smoking, alcohol intake, and SLE disease activity index score. Twenty-eight (46.7%) patients had normal BMD, 28 (46.7%) had osteopenia, and four (6.6%) had osteoporosis. Duration of SLE significantly correlated with cumulative CS dosage. In conclusion, 6.7% of these Asian premenopausal SLE women had osteoporosis and only 46.7% had normal BMD. Daily dietary calcium intake did not correlate with BMD.

Absorptiometry, Photon↗
PubMed2006

Automated microscopy system for mosaic acquisition and processing.

An automatic mosaic acquisition and processing system for a multiphoton microscope is described for imaging large expanses of biological specimens at or near the resolution limit of light microscopy. In a mosaic, a larger image is created from a series of smaller images individually acquired systematically across a specimen. Mosaics allow wide-field views of biological specimens to be acquired without sacrificing resolution, providing detailed views of biological specimens within context. The system is composed of a fast-scanning, multiphoton, confocal microscope fitted with a motorized, high-precision stage and custom-developed software programs for automatic image acquisition, image normalization, image alignment and stitching. Our current capabilities allow us to acquire data sets comprised of thousands to tens of thousands of individual images per mosaic. The large number of individual images involved in creating a single mosaic necessitated software development to automate both the mosaic acquisition and processing steps. In this report, we describe the methods and challenges involved in the routine creation of very large scale mosaics from brain tissue labelled with multiple fluorescent probes.

Journal Article↗
PubMed2004

Nasopharyngeal intraepithelial lesion: latent Epstein-Barr virus infection with malignant potential.

AIMS: To study the morphology and immunohistochemical expression of nasopharyngeal intraepithelial lesions and to understand their place in nasopharyngeal carcinogenesis. METHODS AND RESULTS: Nine cases of nasopharyngeal intraepithelial lesion (NPIL) were diagnosed during nasopharyngeal biopsy screening for nasopharyngeal carcinoma (NPC). Two cases were associated with early invasion. All cases demonstrated specific histological features and consistent positivity on in-situ hybridization for Epstein-Barr virus (EBV)-encoded RNA. Pure NPIL lesions showed low-grade morphology while lesions associated with early invasion were high grade. Immunohistochemical studies showed increased expression of bcl-2 and essentially negative findings for BZLF1 and LMP1. High-grade lesions had relatively stronger expression of bcl-2 and p53. CONCLUSIONS: NPIL harbours latent EBV infection and has malignant potential. Multiple steps are involved in its occurrence and progression. Low-grade and high-grade lesions should be managed differently.

Adult↗
PubMed2003

Cerebral infarction and cerebral salt wasting syndrome in a patient with tuberculous meningoencephalitis.

A 38-year old female with underlying systemic lupus erythematosus was admitted with tuberculous meningoencephalitis. After an initial good response to anti-tuberculous treatment, she developed cerebral infarction and profound hyponatremia. This was due to cerebral salt wasting syndrome, which has only previously been described in 2 cases. The difficulties in diagnosis and management of this case are discussed.

Adult↗
PubMed2003

A case of severe leptospirosis with pancytopaenia.

Pancytopaenia is a rare clinical presentation of severe leptospirosis. We would like to report a case of severe leptospirosis that progressed to pancytopaenia despite initial penicillin therapy. The patient needed a second course of antibiotic with doxycycline to improve his persistent symptoms and cytopaenia. Persistent pancytopaenia in severe leptospirosis and its management were reviewed.

Doxycycline↗
PubMed2002

IgG anti-beta(2) glycoprotein I antibodies in Malaysian patients with antiphospholipid syndrome and systemic lupus erythematosus: prevalence and clinical correlations.

The aim of this study was to investigate the incidence of IgG anticardiolipin antibody (ACL) and IgG anti-beta(2) glycoprotein I antibody (anti-beta2GPI) positivity in patients with primary or secondary antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE), to assess the association between IgG ACL and anti-beta2GPI, and the relationship between the presence of ACL and anti-beta2GPI with the clinical manifestations of APS. IgG ACL and IgG anti-beta2GPI levels were measured in 51 SLE patients, 20 patients with SLE and APS (secondary APS) and 11 primary APS patients using commercially available ELISA kits. Relationships between laboratory data and clinical manifestations of the patients were examined. The incidence of IgG ACL positivity was significantly higher in primary (36.4%) and secondary (40%) APS than in SLE (13.7%) patients (P = 0.02). The incidence of IgG anti-beta2GPI positivity was significantly higher in primary (54.5%) and secondary (35%) APS than in SLE (7.8%) patients (P = 0.0006). Mean levels of IgG ACL and anti-beta2GPI were significantly higher in the primary and secondary APS than in the SLE patients (P = 0.002 for both). A significant relationship was found between IgG ACL and IgG anti-beta2GPI (P = 0.01, R(2) = 0.56). There was a significant correlation between the presence of IgG ACL and a history of thrombosis in the combined primary and secondary APS group, but not in SLE patients. In conclusion, in this study IgG ACL and IgG anti-beta2GPI are closely related and mean levels of IgG ACL and IgG anti-beta2GPI are higher in patients with either primary or secondary APS than in SLE patients.

Adult↗
PubMed2002

HLA-DRB1 genes and susceptibility to rheumatoid arthritis in three ethnic groups from Malaysia.

Worldwide population studies have generally agreed that rheumatoid arthritis (RA) is associated with a group of HLA-DRB1 alleles which share a common amino acid sequence at residues 70-74. This represents the first study to investigate the association of HLA-DRB1 genes with susceptibility to RA amongst Malay, Chinese and Indian ethnic groups in Malaysia. One hundred and thirty three RA patients and one hundred and sixty seven healthy controls were recruited. The HLA-DRB1 alleles were studied using the Phototyping method. The subtypes of HLA-DR4 were detected by "high resolution" PCR-SSP DRB1*04 typing techniques. The prevalence of HLA-DRB1*0405 was significantly higher in Malay patients with RA than in healthy controls (28.9 vs. 8.3%, p = 0.0016, OR = 4.48, 95% CI = 1.26-16.69). Similarly, DRB1*0405 was more common in Chinese RA patients than in controls (30.0 vs. 6.7%, p = 0.0029, OR = 6.00, 95% CI = 1.67-23.48). In addition, DRB1*0901 was a predisposing factor (32.0 vs. 6.7%,p = 0.0015, OR = 6.59, 95% CI = 1.85-25.64) and *0301/04 had a protective role (4.0vs. 25.0%, p = 0.00562, OR = 0.13, 95% CI = 0.02-0.62) in Malaysian Chinese RA. RA in Indians was associated with DRB1*1001 (51.1 vs. 8.5%,p = 0.00002, OR = 11.24, 95% CI = 3.13-44.18). DRB1*0701 (13.3 vs. 42.6%,p = 0.0022, OR = 2.73, 95% CI = 1.40-5.37) may have a protective effect. Therefore, in the Malaysian population, RA is primarily associated with the QRRAA motif, and we suggest that genetic factors play a crucial role in the pathogenesis of RA, compared to environmental factors.

Alleles↗
PubMed2002

Traditional medicine and food supplements in rheumatic diseases.

This was a prospective survey using a standard questionnaire to determine the prevalence of use of oral traditional medicine and food supplements among patients with rheumatic diseases. Among the 141 patients surveyed, we found that 69% of the patients were consuming food supplements, 35% were using traditional medicine and 45% had used traditional medicine at some time or other. Females were more likely to use food supplements (P < 0017); especially among those with higher education (p < 0.036). There was no statistical difference between those who had ever consumed compared to those who never used traditional medicines. The Chinese were more likely than others to be using traditional medicine (p < 0.007). Vitamin C and B were the most commonly used food supplements. More than two thirds of the patients obtained their traditional medicine from non-medical personnel. More than half of them used 2 or more types of traditional medicine for more than two months. Spending on traditional medicine was noted to be modest with 73% spending less than one hundred ringgit a month for their traditional treatment. Doctors need to be aware of the possible interactions between these 'self-medications' and the conventionally prescribed medication.

Adult↗
PubMed2002

Comparison of treatment regimes for lupus nephritis.

The best therapeutic choice in the treatment of lupus nephritis remains open to debate. In addition, there have been little data on the treatment of lupus nephritis in Asian patients. The objective of this study was to look at the response rate and complications of treatment given for lupus nephritis in a group of South East Asian patients with systemic lupus erythematosus (SLE). This was a retrospective, cross-sectional study of 103 patients with lupus nephritis. Detailed analysis was done on 58 patients with Class IV disease. The median time to remission was 12.1 months for azathioprine (AZA), 15.01 months for oral cyclophosphamide (CPM) and 15.25 months for intravenous (i.v.) CPM. The percentage of patients achieving remission after the first course of treatment was 42.9% with AZA, 83.3% with oral CPM and 90.9% with i.v. CPM. Overall, 41/58 (70.7%) of patients went into remission following the first course of treatment. Seventeen (41.5%) subsequently relapsed, requiring a second course of treatment. Fifty-two (50.5%) of all patients had drug-related complications from their treatment. The most frequent complication for the group was amenorrhoea (23.3% of all patients, 40% of those who had CPM previously), which was significantly more frequent in patients given CPM. In conclusion, more patients achieve remission when treated with CPM compared with AZA alone but this is associated with a higher complication rate, especially amenorrhoea.

Adult↗
PubMed2001

Mortality patterns in Malaysian systemic lupus erythematosus patients.

A retrospective analysis of the case records of 494 systemic lupus erythematosus (SLE) patients under follow-up at University Hospital, Kuala Lumpur during 1976-1990 was performed. Overall mortality was 20.2% (100 patients). The causes of death were infection (30%), renal (15%), respiratory (14%), neurological (5%), cardiovascular (7%), other causes (2%) and unknown (27%). Active SLE was a contributing factor in 19% of the deaths. The patients who died had significantly more renal disease, neurological disease, serositis or thrombocytopenia by the end of the first year of disease compared to the survivors. As in other series, infection and active SLE remain important causes of death.

Adult↗
PubMed2000

Amyopathic dermatomyositis and pulmonary fibrosis.

'Amyotrophic dermatomyositis' (ADM) is used to describe a small subgroup of patients with the typical skin rash associated with dermatomyositis but without muscle involvement. Lung involvement in ADM is rare. We report on the management of a patient with ADM associated with pulmonary fibrosis at presentation, and her response to corticosteroid treatment.

Dermatomyositis↗
PubMed2000

The spectrum of ocular involvement in patients with systemic lupus erythematosus without ocular symptoms.

The aim of the study was to determine the spectrum of clinical ocular involvement in patients with inactive systemic lupus erythematosus (SLE) who have no ocular symptoms. Patients with a diagnosis of SLE based on the 1982 revised American College of Rheumatology criteria and with no ocular complaints were recruited from the SLE clinic. Clinical data regarding their systemic disease and disease activity were recorded and a full ophthalmic examination carried out. 52 patients of mixed ethnicity comprising of 75% Chinese, 19% Malays and 6% Indian patients were recruited. Of these, 51 (98%) were female with a mean age of 34+/-11 (range 16-74 y). 16 (31%) patients had dry eyes while corticosteroid induced glaucoma and cataract was detected in 1 (2%) and 7 (14%) patients, respectively. No patients were found to have sight-threatening ocular conditions such as cotton wool spots, vasculitis, optic neuropathy or uveitis. Patients with clinically inactive disease were found not to have sight-threatening ocular diseases that are known to be associated with SLE. Although they have no ocular complaints, nearly one-third of these patients have dry eyes. Ocular examination may be unnecessary when the disease is clinically inactive and in the absence of ocular symptoms.

Adolescent↗
PubMed1998

Primary tuberculous tracheitis.

We report a case of primary tuberculous tracheitis in an otherwise healthy woman who presented with cough and stridor due to diffuse tracheal narrowing by tuberculous pseudomembranous lesion, which resolved completely with antituberculosis chemotherapy.

Antitubercular Agents↗
PubMed1992

Infratemporal pneumatocele arising from maxillary sinus.

Pneumatocele of the infratemporal fossa caused by herniation of air through a break in the wall of the aerated maxillary sinus is rare. Two cases are reported: one arising from a maxillary pneumocele with a defect in the wall of the zygomatic recess and one associated with maxillary radionecrosis with pathological fracture complicated by infection. Computed tomography can clearly demonstrate the extent of the pneumatocele, and can show the maxillary pathology and the causative bony defect in the sinus. Treatment depends on the clinical conditions of the patient, the pathology and the size of the bony defect.

Adult↗
PubMed1989

The Tessier number 9 cleft.

The clinical, radiologic, and operative examination of two patients with the Tessier number 9 cleft has allowed the first complete description of this, the rarest of the rare craniofacial clefts. Soft-tissue disruption extends from the lateral third of the upper eyelid through a distorted lateral end of the eyebrow to the temporal scalp, with an associated hairline indicator. The skeletal disturbance similarly radiates superolaterally from the superolateral orbital rim across the greater wing of the splenoid to the upper squamous temporal. The three-dimensional extent of the bony disruption is associated with distortion of the cranial base and calvaria above.

Abnormalities, Multiple↗
PubMed1988

Primary reconstruction of the mandible after excision of large benign lesions.

Small benign lesions occurring in the mandible, such as dental cysts or adamantinoma, are treated adequately by the dental surgeon using an intraoral approach and curettage (Brånemark et al., 1975). However, larger and recurrent lesions are better treated via the submandibular route (Boyne, 1969). After lesion clearance, the bone gap in the mandible needs to be bridged properly to avoid disabling functional and cosmetic results. This paper describes a modified conventional method of reconstruction which is simple and effective and gives excellent long-term results.

Adolescent↗