Biomedical subjects

E T Koh

Publications and source records attributed to E T Koh.

At least 37 records · Page 2Linked to original sources

PubMed1998

Clinical predictors of nephritis in systemic lupus erythematosus.

We identified clinical predictors of lupus nephritis presenting more than 6 months after the diagnosis of lupus in a cohort of 335 lupus patients. Almost 24% (80/335) of patients developed nephritis more than 6 months after the diagnosis of lupus. Using a Cox proportional hazards model, we found hypertension, thrombocytopaenia and leukopaenia to be associated with lupus nephritis presenting more than 6 months after diagnosis, with adjusted relative risks of 2.5 (95% CI 1.3 to 4.7), 4.3 (95% CI 1.7 to 10.8) and 3.2 (95% CI 1.7 to 6.2) respectively. In this cohort, hypertension, thrombocytopaenia and leukopaenia were associated with lupus nephritis presenting more than 6 months after the diagnosis of lupus.

Adult↗

PubMed1998

Synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome: a brief review of a rare condition.

Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis (SAPHO) syndrome is an osteoarticular-skin syndrome characterised by sterile inflammatory arthro-osteitis of the anterior chest wall. It is associated with various skin conditions including palmoplantar pustulosis, severe acnes and pustular psoriasis. A link between SAPHO syndrome and seronegative spondyloarthropathies has been suggested over the last 10 years. SAPHO syndrome mainly affects young and middle-aged adults. Treatment of SAPHO syndrome remains empirical as the underlying aetiopathogenesis is unclear.

Acne Vulgaris↗

PubMed1998

The effects of ethnicity on disease patterns in 472 Orientals with systemic lupus erythematosus.

OBJECTIVE: To determine the effects of ethnicity on disease manifestations in Oriental patients with systemic lupus erythematosus (SLE) and to describe the risk of developing renal or central nervous system (CNS) involvement with time. METHODS: A retrospective study of 472 patients with SLE seen at the only Rheumatology Unit in Singapore. The effect of ethnicity on selected disease manifestations at diagnosis was assessed after adjusting for demographic variables using multiple logistic regression. The probability of developing selected disease manifestations with time was determined using the Kaplan-Meier product limit method. RESULTS: At diagnosis, Malays had a higher risk of renal or CNS involvement than Chinese (OR 2.26, 95% CI 1.21 to 4.21, and OR 3.07, 95% CI 1.01 to 9.34, respectively), and Indians a lower risk of malar rash and a higher risk of oral ulcers than Chinese (OR 0.30, 95% CI 0.13 to 0.68, and OR 2.90, 95% CI 1.45 to 7.34, respectively). The prevalence of renal or CNS involvement in the entire cohort increased with time, reaching 75.6% (95% CI 66.1% to 85.0%) and 16.7% (95% CI 11.7% to 21.6%), respectively, after 18 years of disease. CONCLUSION: Ethnicity influenced disease manifestations at diagnosis in this cohort of Oriental patients with SLE. Renal or CNS involvement developed in previously unaffected patients up to 18 years after diagnosis, highlighting the need for continued vigilance in patients with lupus.

Adolescent↗

PubMed1998

Cross cultural adaptation and validation of the Chinese Health Assessment Questionnaire for use in rheumatoid arthritis.

OBJECTIVE: The Health Assessment Questionnaire - Disability Index (HAQ), used as a disability and outcome measurement in rheumatoid arthritis (RA), has been validated in several languages, but not in Chinese. Our aim was to validate the Chinese version of HAQ (Chinese-HAQ) to suit the needs of Chinese speaking patients with RA in an Asian setting. METHODS: The original HAQ was modified in the context of Chinese culture and translated into Chinese by 2 translators aware of the objective of the questionnaire. The Chinese HAQ was self-administered by 42 patients with RA during their routine followup visit and one week later. RESULTS: The test-retest reliability assessed using Spearman's correlation coefficient was 0.84. Between dimensions measured in the HAQ, the highest test-retest reliability was observed for walking (Spearman correlation coefficient rs=0.80) and the lowest was for eating (rs=0.54). The internal consistency of the scale using Cronbach's alpha was high at 0.86. In terms of criterion validity, the Chinese-HAQ score was found to correlate well with American College of Rheumatology functional status (rs=0.501, p=0.01). The Chinese-HAQ scores also correlated well with markers of disease activity such as patient's perception of pain measured on a visual analog scale (rs=0.55, p < 0.001), grip strength in mm Hg (rs=-0.55. p < 0.001 ), and physician's assessment of disease activity (rs=0.59, p < 0.001). CONCLUSION: The Chinese HAQ is a reliable and valid instrument for studies measuring disability of patients with RA in Singapore.

Adult↗

PubMed1998

One hundred and seventy cases of childhood-onset rheumatological disease in Singapore.

One hundred and seventy patients with rheumatological disease diagnosed before their 16th birthday and still on follow up were studied retrospectively. They were seen within the last 3 years at KK Women's and Children's Hospital, Tan Tock Seng Hospital, National Skin Centre or Singapore General Hospital. Of these, 89 were still less than 16 years old at the time of study. The majority had systemic lupus erythematosus (51.8%). Many were on long-term follow-up for persistent disease, including renal manifestations (47.7%), neurological manifestations (26.1%) and haemolytic anaemia (15.9%). Photosensitivity and malar rash were more common than in Western studies while arthritis was less common. Anti-phospholipid antibodies were found in children complicated by myocardial infarction, pulmonary hypertension, Raynaud's phenomenon, cerebral and gut lupus. Children with juvenile chronic arthritis comprised 28.8% and juvenile dermatomyositis 10%. The male predominance and lack of uveitis in children with pauciarticular JCA were striking. Rarer conditions included polyarteritis nodosa, scleroderma, rheumatic fever with arthritis, polychondritis and Behcet's disease. Many diseases may first present with a rheumatological complaint. This review of features of local children highlights similarities and differences with Western data. It also provides information for planning long-term care, multidisciplinary clinics, group physiotherapy sessions, educational programmes and support groups.

Adolescent↗

PubMed1998

Congenital sodium diarrhoea in an Indian girl.

We report the case of a newborn Indian girl with congenital sodium diarrhoea (CSD) who presented typically in utero, in whom diagnosis was made from markedly raised stool sodium in the presence of an alkaline stool. Treatment with sodium citrate normalised her metabolic and electrolyte status but resulted in transient uremia necessitating supplementation with sodium bicarbonate instead. She died at 11 weeks old following re-admission in a moribund state with grossly increased abdominal distension. Her fatal outcome in infancy suggests that CSD has a wide spectrum of clinical severity.

Citrates↗

PubMed1997

Mineral trioxide aggregate stimulates a biological response in human osteoblasts.

We report a novel material that appears to stimulate cytokine production in human osteoblasts and allow good adherence of the cells to the material. We have examined cultured osteoblasts (MG-63) in the presence of mineral trioxide aggregate (MTA) as set in moist conditions; secondly, we examined the behavior of these MG-63 cells with respect to cytokine and osteocalcin production and alkaline phosphatase activity. Standard ELISA assays were used for assessment of interleukin (IL)-1 alpha, IL-1 beta, IL-6, macrophage colony stimulating factor (M-CSF), and osteocalcin. Furthermore the levels of alkaline phosphatase were measured to establish the level of differentiation of the cells. Cells without MTA served as controls. Cells also were grown in the presence of polymethylmethacrylate (PMA), the commonly used orthopedic cement. In all dishes cells were seen adhering to the base and MTA at 6 h and had increased to confluence at 144 h. IL-1 alpha (175.1 +/- 32.6 pg/mL), IL-1 beta (154.0 +/- 26.7 pg/mL), and IL-6 (214.7 +/- 21.8 pg/mL) were raised when the cells were grown in the presence of MTA at 144 h, with raised values at all time intervals. M-CSF appeared to be unaffected although the overall value was high (7,045.0 +/- 89.5 pg/mL). In contrast, cells grown in the absence of MTA produced negligible amounts of these cytokines (< pg/mL) as did those cells grown in the presence of PMA. Osteocalcin production increased when cells were grown on MTA from 3.8 +/- 0.87 ng/mL to 19.7 +/- 2.8 ng/mL. No osteocalcin could be detected with PMA. Cells in contact with MTA also appeared to have levels of alkaline phosphatase similar to those reported elsewhere (4.3 +/- 0.21 mumol/mg protein/min). No cells could be found attached to PMA and so no alkaline phosphatase activity could be measured.

Alkaline Phosphatase↗

PubMed1997

SLE mortality in an oriental population.

We analysed the causes of 67 deaths, over a 4 y period, in our oriental population with systemic lupus erythematosus (SLE). The median disease duration was 48 +/- 60.5 months (range 1-250 months). The mean age at diagnosis and death were 30 and 35.1 y respectively. SLE alone accounted for death in 30 patients (44.8%), infection in 27 (40.3%), pulmonary embolism in 5 (7.5%), malignancy in 4 (5.9%) and rheumatic heart disease in 1 (1.5%). The major organ involvement in those with active disease at death were SLE related thrombocytopenia (n = 23/44, 52.3%), nephritis (n = 21/44), 47.7%), cerebral lupus (n = 16/44, 36.4%), and pulmonary haemorrhage (n = 12/44, 27.3%). As in other series, SLE and infection were the principal causes of death in our population. During this 4 y period, there was no late death due to atherosclerosis.

Adolescent↗

PubMed1997

Systemic lupus erythematosus: initial manifestations and clinical features after 10 years of disease.

We studied the initial manifestations and late features in our lupus patients. The clinical data of patients fulfilling the American College of Rheumatology criteria for systemic lupus erythematosus (SLE) were entered prospectively for newly diagnosed patients and cumulatively for those with at least 10 years of disease duration. Ninety-seven Group A (newly diagnosed; 86 females and 11 males; mean age 31 years; 83 Chinese, 11 Malays, and 3 Indians) and 58 Group B (more than 10 years disease duration; 56 females and 2 males; mean age 41 years; 50 Chinese, 5 Malays, and 3 Indians) lupus patients were studied. The commonest clinical features in Group A were: haematological (73%), arthritis (57%), malar rash (43%), renal disorder (31%) and photosensitivity (30%). Group B patients had haematological (78%), malar rash (73%), arthritis (69%), renal disorder (59%) and photosensitivity (33%). Renal disorder was significantly increased over the years (P < 0.001). Hypertension was present in 18% (Group A) and 59% (Group B) (P < 0.00001), diabetes mellitus in 5% (Group A) and 10% (Group B) (P = ns), atherosclerosis in 2% (Group A) and 7% (Group B) (P = ns). Cataract formation was not present in Group A patients but was present in 10% of Group B patients. Renal disorders and morbidity factors like hypertension and cataracts increased significantly over the years. Optimum treatment of lupus patients should therefore include close attention to these factors.

Adolescent↗

PubMed1996

Pulmonary hypertension in systemic sclerosis: an analysis of 17 patients.

A retrospective chart review was carried out on 344 patients with systemic sclerosis (SSc) followed prospectively for the occurrence of pulmonary hypertension (PHT). Seventeen patients (4.9%) were found to have PHT. Eight patients had isolated PHT, while in nine PHT was associated with restrictive lung disease (RLD). The subset with RLD developed PHT earlier, but had longer survival than patients with isolated PHT. Patients with limited scleroderma tend to develop isolated PHT, while in those with diffuse disease PHT is associated with RLD. Irrespective of disease type, PHT in SSc has an extremely poor prognosis with a median survival of 12 months following diagnosis.

Adult↗

PubMed1996

Bone histomorphometry of ovariectomized or orchiectomized rats fed a moderately magnesium-deficient fructose diet and treated with exogenous oestrogen or testosterone.

To investigate the effects of sex hormones on bone histomorphometry, and bone density (BMD), 10 week old ovariectomized (OVX), orchiectomized (ORX), and sham-operated (SHAM) rats fed a moderately magnesium-deficient fructose diet were studied. One third of the OVX and ORX rats were injected with beta-oestradiol-3-benzoate; another third, testosterone cypionate; and the remaining SHAM rats, vehicle only. After 14 weeks, a 24 h urine sample was collected for measurements of calcium, phosphorus and cyclic AMP (cAMP). Blood was collected for determination of calcium, phosphorus, and parathyroid hormone (PTH). Femurs and tibias were removed and weighed. Femurs were used to measure bone areas, mineral contents (BMC), and BMD. Tibias were used for bone histomorphometry (that is, trabecular numbers, thicknesses, % areas and separations). Oestrogen treatment increased serum and urine calcium significantly in both OVX and ORX rats, whereas testosterone decreased serum and urine calcium significantly. Oestrogen decreased urinary cAMP and PTH in both OVX and ORX rats, whereas testosterone treatment increased them significantly. Oestrogen treatment increased BMD, trabecular numbers, thicknesses, and % areas, and decreased bone separations in both OVX and ORX rats. In contrast, testosterone did not increase these bone indices in either OVX or ORX rats; rather, it increased bone separations by decreasing bone strength. Testosterone treatment improved trabecular histomorphometry slightly in OVX rats. The results of the present study are concordant with our previous findings that exogenous oestrogen treatment can prevent osteoporosis in either OVX or ORX rats, whereas exogenous testosterone cannot.

Anabolic Agents↗

PubMed1996

Exogenous oestrogen affects calcium metabolism differently from exogenous testosterone in ovariectomized or orchiectomized rats fed a high fructose diet severely deficient in magnesium.

To investigate interactions between sex hormones, dietary fructose, and a severe magnesium deficiency on calcium metabolism, 10 week old ovariectomized (OVX) female, and orchiectomized (ORX) males rats were studied. The OVX and ORX animals were divided into two groups: one half of the animals in each group was injected with beta-oestradiol-3-benzoate dissolved in sesame oil twice a week; the other half was injected with testosterone cypionate in sesame oil twice a week. All animals were pari-fed a severely magnesium-deficient fructose diet. After a 4 week experimental period, a 24 h urine sample was collected for measurements of cAMP, calcium, magnesium, and phosphorus. Blood was collected for determination of calcium, magnesium, phosphorus, 25-hydroxy- and 1.25-dihydroxycholecalciferol [25(OH)D, 1.25(OH)2D], and parathyroid hormone (PTH). Femurs were used for measurements of bone mineral content (BMC) and density (BMD). Oestrogen treatment produced hypercalcaemia and hypercalciuria, and, further, this was higher in female than in male rats. In contrast, testosterone treatment produced hypocalcaemia and hypocalciuria. Hypocalcaemia in testosterone-treated animals may stimulate secretion of PTH. Testosterone-treated animals had significantly lower BMD than oestrogen-treated animals. High circulating PTH seemed to cause bone loss in the testosterone group. High PTH may stimulate hydroxylation of 25(OH) D to 1.25(OH)2D in the kidneys, and high circulating 1.25(OH)2D would antagonize bone formation. Either endogenous or exogenous oestrogen increased kidney calcification. The study indicates that oestrogen-fructose-magnesium interaction on calcium metabolism was significantly different from that of testosterone.

Anabolic Agents↗

PubMed1996

A comparison of clinical and endoscopic features of bleeding and non-bleeding peptic ulcer in Singapore.

Two hundred and seventy-seven consecutive cases of peptic ulcer patients were compared. Of these, 103 presented with acute gastrointestinal haemorrhage and 174 presented with pain. The median age of those who bled (53 years) was not significantly higher than those who presented with pain (50 years) (P > 0.05). Bleeding peptic ulcer patients, when compared to non-bleeding ulcer patients, tended to present with a past history of gastrointestinal haemorrhage, have ingested non-steroidal anti-inflammatory drugs, and have, at endoscopy, ulcers greater than 1.5 cm in diameter. The site and number of ulcers did not influence the mode of presentation. About 60% of bleeding ulcers were found in the duodenum and this proportion of duodenal ulcers was not significantly different in both groups of patients. Gastric ulcer patients who bled tended to be significantly associated with ingestion of non-steroidal anti-inflammatory drugs. Gender and ethnic distribution, smoking and alcohol ingestion were all not associated with the presentation of haemorrhage.

Adult↗

PubMed1995

Pericardial effusion and vasculitis in a patient with systemic sclerosis.

We describe a case of diffuse scleroderma with a large pericardial effusion, pleural effusions, and subsequent oliguric renal failure. Histology of the pericardium and pleura revealed the presence of leukocytoclastic vasculitis. Pleuropericarditis in systemic sclerosis may occur on the basis of vasculitis. Large pericardial effusions may predispose to subsequent renal failure.

Female↗

PubMed1994

Sexual differences in the magnocellular vasopressinergic system in golden hamsters.

Golden hamsters, as compared to rats, lack several parvicellular vasopressinergic cell groups, particularly sexually dimorphic populations. We decided to test the possibility that magnocellular vasopressinergic neurons are subjected to sexual differences in hamsters, as they are known to display vasopressin (AVP)-dependent sexually dimorphic behaviors. The distribution of magnocellular vasopressinergic neurons was mapped and compared between males and females. Approximately 50% more vasopressin-immunoreactive (AVP-ir) neurons were counted in males within the medial and lateral divisions of the supraoptic nucleus. Furthermore, levels of AVP extracted from the hypothalamus and the pituitary gland were three to four times higher in males than in females. Finally, hypothalamic extracts from a male and a female hypothalamus were fractionated by HPLC and assayed for AVP immunoreactivity. Immunoreactivity from each extract had the same retention time as synthetic AVP standards; and the levels were twice as high in the male. These results support the existence of sexual differences in the magnocellular vasopressinergic system in golden hamsters. These differences appear to be related to previously reported sexual differences in AVP secretion from the neurohypophysis.

Animals↗

PubMed1994

Oestrogen but not testosterone increases bone density in orchiectomized rats more when fed moderately magnesium-deficient fructose than moderately magnesium-deficient cornstarch.

To investigate interactions between circulating sex hormones, dietary fructose and magnesium on bone mineral density and numbers of trabeculae, 10 weeks old orchiectomized and sham-orchiectomized rats were studied. One-third of the orchiectomized animals were injected with beta-oestradiol-3-benzoate twice per week in sesame oil; another one-third, testosterone cypionate; the remaining one-third as well as the sham-orchiectomized animals, sesame oil only. All animals were fed either fructose or cornstarch without added magnesium. After 14 weeks, a 24 h urine sample was collected for measurements of calcium, magnesium, phosphorus, and cAMP. Blood was collected for determinations of calcium, magnesium, phosphorus, 25-monohydroxy and 1,25-dihydroxycholecalciferols, oestrogen, testosterone, and parathyroid hormone. Femurs were used for measurements of bone mineral density, and tibiae, for numbers of trabeculae. Exogenous testosterone interacted with starch and magnesium deficiency to decrease serum calcium concentration significantly, which increased circulating parathyroid hormone. High circulating parathyroid hormone raised urinary cAMP and serum 1,25-dihydroxycholecalciferol. Increased parathyroid hormone, cAMP and 1,25-dihydroxycholecalciferol may be responsible for bone resorption which was noted in reductions of bone mineral density and the numbers of trabeculae in the group. In contrast, exogenous oestrogen interacted with fructose and magnesium deficiency to increase serum calcium concentration which caused a reduction of circulating parathyroid. Low parathyroid hormone, reduced 1,25-dihydroxycholecalciferol and cAMP may explain the increased bone mineral density and the numbers of trabeculae in this group.

Animals↗

PubMed1994

Lipid profiles in patients with systemic lupus erythematosus.

OBJECTIVE: To determine the prevalence of abnormal lipid profiles in 100 consecutive patients with systemic lupus erythematosus (SLE) and the role of potential risk factors. METHODS: Fasting lipid profiles were measured using an enzymatic method. Biodata noted for each patient included age, sex, race, presence of diabetes mellitus, thyroid disease, familial hyperlipidemia, smoking history, presence of nephritis or nephrotic syndrome, lupus activity as measured by the lupus activity criteria count (LACC), duration of SLE, use of antihypertensive agents and the current and cumulative dose of steroids. Statistical analysis was done using PC SAS software. RESULTS: Seventy-three patients had abnormal lipid profiles. Patients with normal and abnormal profiles were comparable in age, sex, race, history of diabetes mellitus, familial hyperlipidemia, and smoking. Abnormal values of total cholesterol (TC), low density lipoprotein (LDL), triglycerides (TG) and TC/high density lipoprotein (HDL) were associated with renal involvement and high dose corticosteroids (> 30 mg prednisolone/day). HDL levels were significantly lower in patients receiving high dose corticosteroids (p < 0.05). In patients with active lupus disease but without renal disease, lipid abnormalities were not observed. CONCLUSION: Abnormal lipid profiles are common in this group of patients with SLE. High dose steroids and the nephrotic syndrome are important contributing factors.

Adult↗

PubMed1994

Late onset lupus: a clinical and immunological study in a predominantly Chinese population.

OBJECTIVE: To compare retrospectively the clinical, laboratory, and immunological features between 50 patients with early and 26 with late onset (> 50 years old) systemic lupus erythematosus (SLE) and to observe differences between our predominantly Chinese and Caucasian patients with late onset SLE. METHODS: Case records of 76 consecutive patients (age: 10-73 years) who attended the rheumatology clinic during the study period were reviewed. Chinese constituted 89.4% of the study population. RESULTS: Compared to the early onset patients, the late onset lupus patients tended to have an insidious onset of disease, lower female predominance and less frequent complaints of fever, alopecia, arthritis, and malar rash at presentation (p < 0.05). Peripheral neuropathy, myalgias, pancytopenia, and elevated liver enzymes were more commonly found in the late onset than in the early onset lupus during followup. Major organ involvement was relatively uncommon in late onset patients. No sex related differences could be demonstrated with respect to the mean age of onset of disease and clinical manifestations. No significant serological differences were detected between the 2 groups. The cause of death in the late onset group was often treatment related. CONCLUSION: Differences in disease manifestations were found between the early and late onset lupus patients. The disease expression in our predominantly Chinese elderly patients with lupus also differs from the Caucasian patients. However, the insidious onset and milder disease in the late onset group is in agreement with other studies.

Adolescent↗