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Biomedical subjects

K L Khoo

Publications and source records attributed to K L Khoo.

At least 19 recordsLinked to original sources
PubMed2004

Pulmonary hypereosinophilia.

INTRODUCTION: Eosinophilic lung diseases are a diverse group of pulmonary disorders linked by the common finding of increased eosinophilia in blood and/or tissue. They usually present to the clinician as pulmonary infiltrates with eosinophilia for which the differential diagnoses is fairly broad. CLINICAL PICTURE: Three patients presented with subacute cough, pulmonary infiltrates and a markedly elevated eosinophil count >1.5 x 109/L. Each case exemplifies its clinical peculiarities and pearls and illustrates the diversity in this group of disorders. TREATMENT: A common theme in the approach to its management is excluding infection before proceeding with therapy, often with steroids. OUTCOME: There is often a dramatic response to steroid therapy with resolution of symptoms and chest radiographic findings. CONCLUSION: The arbitrary label of "pulmonary hypereosinophilia" enables the differential diagnoses to be narrowed to the 4 main categories of infections with parasites or fungus, the Churg-Strauss syndrome, chronic eosinophilic pneumonia and the idiopathic hypereosinophilic syndrome.

Adult↗
PubMed2003

Lipids and coronary heart disease in Asia.

In Western countries, it has been shown that coronary heart disease (CHD) is related to high serum total cholesterol (TC) levels. In less developed continents such as Asia and Africa, serum lipid levels are low and CHD incidence is much lower as compared with Western countries. With growing urbanization and industrialization in Asia, it has been shown that there is a concomitant rise in the level of serum TC and with it a rise in CHD. In all the Asian countries, serum TC levels are also higher in the urban compared with the rural population. Singapore, the only Asian country which is 100% urbanized since 1980, showed a rise of serum TC similar to that seen in the US and UK from the 1950s to the 1980s followed thereafter by a fall. This is reflected in the trend (rise followed by a fall) of CHD morbidity and mortality as well. In spite of a declining trend in serum TC level, CHD morbidity and mortality are still high in Singapore and comparable to the Western countries. The rest of the Asian countries show a different pattern from Singapore. In general, there is still a rising trend in serum TC level and in CHD mortality in most Asian countries. However, Japan is considered an exception in having a decreasing CHD mortality in spite of an increasing trend in serum TC. This may be attributed to a better control of other CHD risk factors such as hypertension and smoking. The rising trend in serum TC level remains a cause for concern, as this will emerge as a major problem for CHD morbidity and mortality in the future.

Asia, Southeastern↗
PubMed2000

Low-density lipoprotein receptor gene mutations in a Southeast Asian population with familial hypercholesterolemia.

The aim of this study was to detect mutations in the genes coding for the low-density lipoprotein receptor and apolipoprotein B in patients of Southeast Asian origin with clinically diagnosed familial hypercholesterolemia (FH) and to relate these findings with the observed lower incidence of coronary heart disease in this part of the world. A total of 86 unrelated patients with FH were selected on clinical grounds, and complete DNA analysis of the low-density lipoprotein (LDL)-receptor and apolipoprotein B (apoB) genes by DGGE and DNA-sequencing was performed. In the majority (73%) of the cohort studied, no mutations could be detected, even after extensive analysis of the LDL-receptor and apoB genes. However, the 22 patients with a mutation had significantly more xanthomas and a higher incidence of coronary heart disease and levels of low-density lipoproteins were also significantly different. There was no correlation between the type of the mutation and lipoprotein levels or clinical signs of atherosclerosis. The fact that the majority of the FH patients studied had no detectable mutation and that this group had a significant milder phenotype, suggests the presence of a third gene in the Southeast Asian population, predominantly leading to a disorder resembling a milder form of FH. A similar, but less frequent, trait has recently been described in a number of European families.

Adult↗
PubMed2000

Endobronchial mass in a patient with Burkholderia pseudomallei infection.

INTRODUCTION: Burkholderia pseudomallei infection, the great mimicker of infectious diseases, has protean clinical manifestations. CLINICAL PICTURE: A 37-year-old man who presented with community-acquired pneumonia affecting the right upper lobe had unremitting fever. Bronchoscopy showed an endobronchial mass in the right upper lobe bronchus. TREATMENT: Intravenous ceftriaxone and oral erythromycin, with empiric antituberculous treatment added later. This was subsequently switched to intravenous ceftazidime and oral doxycycline after the diagnosis was made. OUTCOME: There was resolution of the endobronchial mass. CONCLUSION: This case illustrates a unique and unreported presentation of melioidosis.

Adult↗
PubMed2000

Genetic causes of familial hypercholesterolaemia in a Malaysian population.

A total of 86 unrelated Malaysian patients with familial hypercholesterolaemia (FH) were studied for mutations in their low-density lipoprotein receptor (LDL-R) gene. Amongst them, 23 had a LDL-R gene mutation, while none having an Apolipoprotein B-3500 (Apo B-3500) mutation. Patients with the LDL-R gene defect appeared to have a higher level of low-density lipoprotein cholesterol (LDL-C), an increased incidence of xanthomas and coronary heart disease (CHD), but no relationships were found between the type of LDL-R gene mutations and their lipid levels or clinical signs of CHD. In contrast to Western data, our findings seemed to indicate a predominance of mutations in the ligand binding domain and an absence of Apo B-3500 gene mutation. The latter finding may offer a genetic basis as to why Asian patients with familial hypercholesterolaemia have lower LDL-C levels and less premature CHD than their Western counterparts.

Adult↗
PubMed2000

Blood pressure, body mass index, heart rate and levels of blood cholesterol and glucose of volunteers during National Heart Weeks, 1995-1997.

The paper presents the results of a health screening programme conducted in 10 major centers in Malaysia--Kuala Lumpur, Penang, Ipoh, Johor Bahru, Alor Star, Kuala Terengganu, Malacca, Kota Bahru, Kuching and Kota Kinabalu during the National Heart Weeks, 1995-1997. There were 6,858 participants of both sexes aged between 6 years to 81 years old. The parameters involved in the screening programme were body mass index, blood pressure, heart rate, cholesterol and glucose. The following are the results of the study:- 1. The mean and standard deviation for the body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), total cholesterol (TC) and non fasting (random) blood glucose (GL) of the volunteers studied were 24.3 +/- 4.0 kg/m2, 128.3 +/- 21.1 mmHg, 79.6 +/- 11.9 mmHg, 77.2 +/- 12.1 bpm, 5.33 +/- 1.37 mmol/l and 5.11 +/- 1.97 mmol/l respectively. 2. There was a rising trend for BMI, SBP, DBP, TC and GL with age. The HR was higher in the younger age group of those below 20 years. Males tended to have higher mean values than females except for HR which was similar in both sexes. 3. The Malays, Chinese and Indians seemed to have closely similar mean values for SBP, DBP and HR but the Indians possessed the highest BMI (25.62 +/- 3.90 kg/m2), TC (5.61 +/- 1.48 mmol/l) and GL (5.41 +/- 2.43 mmol/l) among the three major ethnic groups. While the Ibans had highest TC (6.07 + 1.09 mmol/l), their GL level was the lowest (4.76 +/- 1.15 mmol/l). The Kadazans had the lowest TC level (4.94 +/- 1.39 mmol/l) among all the ethnic groups. 4. Among the participants screened, 31.9% were overweight (BMI > or = 25), 7.6% were obese (BMI > or = 30); 26.8% had raised SBP (> or = 140 mmHg) and 19.3% had raised DBP (> or = 90 mmHg); 13.6% of the participants had increased HR (> or = 90 bpm), 22% had raised TC (> or = 6.20 mmol/l) and 2% had raised GL (> or = 11.00 mmol/l). There was a higher prevalence for abnormal values with increasing age until between the ages of 60 or 70 years, when the values began to fall. 5. Age was positively correlated with SBP (r = 0.41***, df = 4351), DBP (r = 0.27***, df = 4351), TC (r = 0.22***, df = 3303) and GL (r = 0.16***, df = 2442) but negatively correlated with HR (r = -0.13***, df = 4351). The BMI was positively correlated with SBP (r = 0.29***, df = 2769), DBP (r = 0.31***, df = 2769), TC (r = 0.16***, df = 2137) and GL (r = 0.11**, df = 1637) but there was no correlation with HR (r = 0.03NS, df = 2771). The SBP and DBP were highly correlated with each other (r = 0.75***, df = 4351) and they also showed highly significant positive correlation (r = 0.08***-0.13***, df = 2441-3301) with TC and GL. TC was positively correlated with GL (r = 0.05* df = 2319) but only at the 5% probability level.

Adolescent↗
PubMed1999

Rapid mycobacterial tuberculosis detection in bronchoalveolar lavage samples by polymerase chain reaction in patients with upper lobe infiltrates and bronchiectasis.

In areas where tuberculosis is endemic, a positive sputum acid-fast bacilli (AFB) smear is frequently regarded as almost diagnostic of pulmonary tuberculosis (PTB). The main problem arises when the AFB smear is negative. The main aim of this study was to determine the clinical utility of rapid mycobacterial tuberculosis (MTB) detection in bronchoalveolar lavage (BAL) samples by polymerase chain reaction (PCR) in 52 patients who underwent diagnostic bronchoscopy for suspected PTB. These patients had either upper lobe infiltrates (n = 31) or bronchiectasis (n = 21). Mycobacterial culture is usually used as the gold standard of diagnosis. We chose to define active PTB based on positive mycobacterial cultures and/or histological evidence of caseous necrosis and AFB, and/or when there was clinical plus radiological improvement following therapy. We compared AFB smear, respiratory mycobacterial culture, BAL PCR for MTB and clinical active PTB. Four patients who were smear and culture negative had clinical and radiological clearance following anti-tuberculous therapy showing that using mycobacterial culture as a gold standard may have its limitations. When Kappa (a chance-corrected measure of agreement) was calculated for acid-fast bacilli smear and BAL PCR against our definition of active PTB, it was 0.28 (fair agreement) and 0.73 (substantial agreement), respectively. BAL PCR gave a sensitivity, specificity, positive and negative predictive values of 66.7%, 100%, 100% and 88%, respectively, for the group with upper lobe infiltrates. We also demonstrated that BAL for PCR has a good concordance with the final diagnosis of active tuberculosis.

Adult↗
PubMed1999

Ethnicity, obstructive sleep apnoea and ischaemic heart disease.

We studied the relationship between different ethnic groups, obstructive sleep apnoea (OSA) and ischaemic heart disease. Four hundred and thirty-two inpatients from the medical wards were interviewed. Limited overnight sleep studies were done in 129 of those who had habitual snoring, daytime sleepiness based on an Epworth sleepiness scale of 8 or more, or a large neck size of 40 cm or more. There were 315 Chinese (72.9%), 67 Malays (15.5%), 43 Indians (10%) and 3 from other races (1.4%). The prevalence of OSA was 19.7%, 30% and 12% among the Chinese, Malays and Indians, respectively. The prevalence ratio for OSA was 1.52 in Malays using Chinese patients as the baseline (P = 0.07). The median neck circumference was 37 cm in both racial groups. The median body mass index was 22.7 kg/m2 in Chinese compared to 23.6 kg/m2 in Malays. The median apnoea-hypopnoea index was 22.7, 19.0 and 26.9 events/hour among the Chinese, Malays and Indians, respectively. OSA was independently associated with the prevalence of IHD (adjusted prevalence ratio 1.68; 95% CI: 1.15, 2.46; P = 0.009). The prevalence of ischaemic heart disease (IHD) was 31%, 24% and 28% in Chinese, Malays and Indians, respectively. The prevalence ratio for IHD in Malays compared to Chinese was 0.77. After adjusting for OSA, there was an even greater reduction in the risk of IHD (adjusted prevalence ratio 0.70). This suggests that OSA is a confounder in the relationship between race and ischaemic heart disease.

Adult↗
PubMed1999

Patients' knowledge and attitude towards treatment and control of hypertension: a nation-wide telephone survey conducted in Malaysia.

The telephone survey of 2,526 hypertensive subjects showed 94% of the respondents were aware of the importance in controlling hypertension. Among these 504 were not on anti-hypertensive medication while the majority of 2,022 were currently on anti-hypertensive medication. Of those who were not on medication, 80% (n = 403) were found non-hypertensive on follow-up. The remaining 20% (n = 101) were confirmed hypertensive and were offered medication. However, 38 subjects refused to take medication and 63 subjects complied with medication but subsequently gave up. The main reasons for giving up medication included lack of motivation (38%), doctors' advice (20%), side effects (19%) and concern of side effects (10%). Of 2,022 hypertensive respondents who were currently on medication, almost half (44%, n = 890) required a change of medication due to side effects (40%, n = 356) or the blood pressure not controlled with the previous medication (33%, n = 294). Despite the change in medication, 42% (n = 150) still continued to suffer from some form of side effects. The information obtained from this survey suggested it is important to recommend some strategies to improve patient compliance. These strategies comprise of motivating the patient, improving medication with less side effects, improving potency and efficiency of medication, and reduction of cost in medication. In addition, convenient blood pressure monitoring such as home blood pressure monitoring is also encouraged.

Adult↗
PubMed1998

Aetiology and outcome of severe community-acquired pneumonia in Singapore.

The aim of this study was to determine the aetiology and outcome of severe community-acquired pneumonia, and to assess whether the existing guidelines for initial antimicrobial therapy are being applied. The records of 57 consecutive nonimmunocompromised patients admitted to the medical intensive care unit (ICU) between January 1989 and May 1993 with this diagnosis were reviewed. The microbiological data, chest radiographic changes and outcome were analysed. Nine (16%) of the 57 patients had pulmonary tuberculosis. When these patients were excluded from further analysis, a microbiological diagnosis was made in 41 (72%) cases. The most commonest pathogens were Burkholderia pseudomallei (n=10), Klebsiella spp. (n=5) and Staphylococcus aureus (n=5), Mycoplasma pneumoniae (n=4) and Streptococcus pneumoniae (n=2) were less common. This microbiological spectrum was quite different from that in the West, where the incidence of S. pneumoniae was higher. Also, when pulmonary tuberculosis was excluded, the mortality (67%) was much higher than that in other series. This was attributed to the high incidence of unrecognized B. pseudomallei infection, which is associated with a very high mortality in the region under study. In addition to applying published guidelines on severe community-acquired pneumonia, the endemicity of certain organisms such as Mycobacterium tuberculosis and Burkholderia pseudomallei in different geographical regions needs to be considered when choosing initial empirical antimicrobial therapy.

Adolescent↗
PubMed1998

Malaria requiring intensive care.

We studied 24 consecutive adult patients with malaria who required intensive care between 1 January 1994 and 31 December 1997. This was out of a total of 256 patients hospitalised at the Singapore General Hospital with malaria during these 4 years. Our aim was to characterise the type and severity, clinical features, complications, treatment and outcome of adult patients with malaria who required intensive care. In addition, we compared the actual and predicted mortality based on the Acute Physiology and Chronic Health Evaluation II (APACHE II) score. The travel history, prophylaxis, duration of fever before receiving treatment, type of malaria and severity, clinical data, complications, APACHE II score, treatment and outcome were analysed. Most cases were imported by locals travelling overseas or foreigners infected with the parasite elsewhere. Four patients had vivax malaria and 20 patients had severe falciparum malaria. All but 1 patient received transfusion with blood products and 6 patients with severe falciparum malaria had exchange transfusions. Complications were restricted to infection with P. falciparum: 9 patients required acute dialysis and 8 required mechanical ventilation. Three patients died giving a mortality of 15% for severe falciparum malaria. The overall mortality of patients with malaria was 1.2%. The mortality of patients with malaria requiring intensive care was 12.5% as compared with a predicted mortality of 18.7% based on the APACHE II prognostication system.

APACHE↗
PubMed1997

Serum lipids and their relationship with other coronary risk factors in healthy subjects in a city clinic.

Over a thousand subjects who visited a city private medical clinic for health screening and advice were examined for their lipid profile and other cardiovascular risk factors. The mean TC, TG, LDL-C and HDL-C were 5.43, 1.45, 3.61 and 1.15 mmol/l. Their derived ratios viz, TC:HDL-C and LDL:HDL-C were 5.11 and 3.43 respectively. The prevalence of hyperlipidaemia was moderately high. Of the subjects studied 58.5% had elevated serum cholesterol, 14.8% had raised triglycerides, 64.9% had raised LDL-C and 20.8% had low HDL-C. Male subjects generally showed higher mean values and abnormality frequency in TC, TG, LDL-C, TC:HDL-C and LDL:HDL-C as compared to female subjects. Although significant ethnic differences were not detected for certain lipid parameters (e.g. TC, TG and HDL-C), the Indians appeared to have higher mean lipid values (except HDL-C), and higher percentage abnormality for all the lipid parameters as compared to the Chinese and the Malays. In correlation studies, the following lipid parameters:- TC versus TG, LDL-C, TC:HDL-C; TG versus TC:HDL-C and LDL:HDL-C; LDL-C versus TC:HDL-C and LDL:HDL-C; were positively correlated. On the other hand, TC versus HDL-C, TG versus HDL-C, LDL-C and HDL-C, and HDL-C versus TC:HDL-C and LDL:HDL-C were negatively correlated. The coronary risk factors which generally showed positive correlations with lipid parameters were BMI and blood pressure. Positive correlations were also recorded between fasting blood glucose and TG; uric acid with TG, TC:HDL-C and LDL:HDL-C. In contrast, risk factors of negative correlations were observed between HDL-C and the coronary risk factors of BMI, diastolic blood pressure and uric acid. Smoking showed raised per cent lipid abnormality for TG, HDL-C, TC:HDL-C and LDL:HDL-C. Alcohol consumption also increased the mean level and abnormality frequency for TG. The implication of this investigation is discussed.

Adolescent↗
PubMed1997

Health status of senior civil servants in Kuala Lumpur.

733 senior civil servants comprising 520 males and 213 females with a mean age of 44 years (range 25-56 years) were screened for their health status. The sample population comprised of 67.9% Malays, 22.5% Chinese, 9.1% Indians and 0.4% other ethnic origins. The subjects' medical histories were recorded and a full medical examination including anthropometric measurements (weight, height, waist and hip circumference), blood biochemistry and urine analysis, chest X-ray and electrocardiograms were done. The results obtained showed that 36.0% of the study population were overweight with 6.5% being obese. Of this 32.0% had central obesity. 15.2% of the subjects had systolic hypertension (systolic BP > or = 140 mmHg) whilst 27.6% had diastolic hypertension (diastolic BP > or = 90 mmHg). Hyperlipidaemia was common, with 75.2% subjects having raised cholesterol, 19.9% raised triglycerides, 50.2% raised LDL-C, 74.6% raised TC:HDL-C and 26.6% raised LDL:HDL-C. An elevated blood glucose was found in 8.4% subjects, whilst urine sugar was detected in only 2.6%, and a raised uric acid was found in 2.8% subjects. The prevalence of hypertension, raised blood glucose and hyperlipidaemia increased with age with more males affected than females. Although hypercholesterolaemia appeared more frequently amongst the Malays, the Indians, by comparison had the highest prevalence for a raised LDL:HDL-C ratio, a reflection of the increase in LDL-C and a concomitant decrease in HDL-C. The latter findings indicate that the Indians are at greater risk for the development of coronary heart disease than the Chinese and Malays. In addition, the mean levels of serum cholesterol found in this study seemed to have exceeded the levels found in populations in the industrialised countries such as the USA. There is thus an urgent need for more public health campaigns aimed at the reduction and control of such coronary risk factors.

Adult↗
PubMed1997

Denaturing gradient-gel electrophoresis screening of familial defective apolipoprotein B-100 in a mixed Asian cohort: two cases of arginine3500-->tryptophan mutation associated with a unique haplotype.

The Arg-to-Trp substitution at codon 3500 in the apolipoprotein (apo) B-100 gene is established as a cause of familial defective apo B-100 (FDB), a functional mutation, resulting in reduced LDL receptor binding and manifest hypercholesterolemia. In a search for similar mutations in 163 Malaysians, we screened the putative receptor-binding region (codons 3456-3553) of the apo B-100 gene by PCR amplification and denaturing gradient-gel electrophoresis. Four single-base mutations were detected and confirmed by DNA sequencing. Two females, a Chinese and a Malay, had the same CGG3500-->TGG mutation, resulting in an Arg3500-to-Trp substitution. This is the second published report of such an independent mutation involving the same codon as the established Arg3500-to-Gln mutation. The two other mutations detected, CTT3517-->CTG and GCC3527-->GCT, resulted in degenerate codons with no amino acid substitutions. All four mutations were associated with a unique apo B haplotype, different from those found in Caucasian FDB patients but concurring with that previously reported for two other Asians with FDB.

Adolescent↗
PubMed1997

Current concepts in ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is a common problem in the intensive care unit (ICU). It is associated with a distinct spectrum of pathogens and its pathogenesis involves microaspiration of oropharyngeal organisms. Clinical and radiographic criteria have been shown to be unreliable in diagnosing VAP, and it remains a challenge for intensivists to utilise the array of diagnostic procedures at their disposal to optimise diagnostic accuracy (improve specificity) and guide in therapy. These procedures and guided antibiotic therapy may not always improve the outcome and therefore simple preventive measures should be employed to reduce the incidence.

Humans↗
PubMed1991

Cardiovascular mortality in Peninsular Malaysia: 1950-1989.

Mortality statistics of Peninsular Malaysia for the period 1950-1989 have been studied in relation to cardiovascular diseases, with particular emphasis on coronary heart disease as an important cause of death. It was observed that among six major disease groups reviewed, cardiovascular diseases which occupied third place as a cause of death in 1950 emerged as the number one killer during the 1970s and has remained so since (with exception in 1980). In contrast, infectious diseases which ranked first in 1950 dropped to fourth position in 1980. Between 1960 and 1980, mortality due to cardiovascular diseases was higher in males than in females. This tendency became less apparent during 1985-1989. With reference to race, the incidence of cardiovascular deaths was highest in Indians followed by Chinese and Malays. Among the specific cardiovascular diseases, coronary heart and cerebrovascular diseases accounted for the main causes of mortality. Mortality due to coronary heart disease has increased by more than three fold over the last 40 years and is still rising. However, mortality incidence due to rheumatic heart disease and hypertension decreased during the same period. In 1965, mortality due to coronary heart disease was highest in the 55-59 age group. In recent years (1985 to 1989), it shifted to the older age group (i.e. 65-69). There was a tendency for higher mortality due to coronary heart disease in males compared to females. Indians had a higher mortality due to coronary heart disease than Chinese and Malays.

Age Factors↗