2009

Khadem-Ansari MH, Rasmi Y, Rahimi-Pour A, Jafarzadeh M
Correspondence: Dr Yousef Rasmi, rasmiy@umsu.ac.ir

ABSTRACT
Introduction The aim of this study was to investigate the relationship between serum apolipoprotein A-I (apoA-I) and apolipoprotein B (apoB) and the severity of coronary artery stenosis.
Methods This case-control study was carried out on 106 patients who underwent angiography and 100 healthy controls. ApoA-I and apoB as well as the serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), triglyceride and low-density lipoprotein cholesterol (LDL-C) levels were measured. Very low-density lipoprotein cholesterol levels and the LDL-C/HDL-C ratio were calculated.
Results In an Iranian population with coronary artery disease (79 men and 27 women, aged 53 +/- 8.5 years), the increased levels of apoA-I and apoB were correlated with the number of involved vessels and the severity of coronary lesions. However, no significant correlation was found between the serum values of lipids as well as other lipoproteins and the number of vessels involved and the severity of coronary lesions.
Conclusion ApoA-I and apoB are indicated as risk factors for cardiovascular and, possibly, cerebrovascular diseases. From this study, it may be concluded that apoA-I and apoB serum concentration levels are independent risk factors for coronary atherosclerosis in the Iranian population. It also demonstrates a direct relationship between the severity of coronary atherosclerosis and the number of lesions in the involved vessels. It can be regarded as an index for the relationship of apoA-I and apoB to the early, still clinically asymptomatic, steps of the pathogenesis of coronary disease.

Keywords: apolipoprotein, cardiovascular disease, coronary artery disease, coronary artery stenosis
Singapore Med J 2009; 50(6): 610-613

Abdullah WZ, Idris SZ, Bashkar S, Hassan R
Correspondence: Dr Wan Zaidah Abdullah, wzaidah@kb.usm.my

ABSTRACT
Introduction The fibrinolytic system plays an important role in normal haemostasis and endothelial function. This study was conducted to compare three fibrinolytic markers, i.e. plasminogen, tissue-plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) between acute stroke and stable non-stroke patients and to investigate the clinical significance of these markers.
Methods A prospective study was done for a one-year period upon obtaining ethical approval from the local institution. 106 non-stroke individuals from general outpatient clinics (control group) and 51 acute stroke patients were selected. All subjects were tested for t-PA and PAI-1 levels using the enzyme immunoassay technique (Biopool TintElize®) and for plasminogen level by colorimetric assay (HemosILTM). They were followed up over a period of three months for survival and neurological recovery.
Results Only the mean t-PA level was significantly higher in acute stroke patients compared to the control group, including after adjusting for confounders (using ANCOVA). There was no statistical association between the three fibrinolytic markers and the age, gender, stroke subtypes, number of risk factors, functional impairment, survival and neurological recovery. We observed that all the eight patients who died within one month of stroke onset had high levels of t-PA. An association between high t-PA antigen and acute stroke was found during a cerebrovascular event with a 4.6-fold odds ratio compared to non-stroke controls.
Conclusion High t-PA antigen in acute stroke patients probably indicates a poor prognosis. Its value as a marker for monitoring and prognostication needs to be evaluated as a routine clinical practice.

Keywords: acute stroke, plasminogen, plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA)
Singapore Med J 2009; 50(6): 604-609

Agarwal R, Aggarwal AN, Gupta D
Correspondence: Dr Ritesh Agarwal, riteshpgi@gmail.com

ABSTRACT
Introduction Noninvasive ventilation (NIV) with continuous positive airway pressure (CPAP) has been shown to decrease endotracheal intubation and mortality in patients with acute cardiogenic pulmonary oedema (ACPE). The Three Interventions in Cardiogenic Pulmonary Oedema showed no advantage of NIV over standard medical therapy. This meta-analysis is an update on the efficacy and safety of two different forms of NIV (noninvasive pressure support ventilation [NIPSV] vs. CPAP) in patients with ACPE.
Methods We searched the MEDLINE and EMBASE databases for randomised clinical trials published from 1980 to 2008 that have compared NIPSV and CPAP in patients with ACPE. We calculated the odds ratio (OR) with 95 percent confidence intervals (CI) and pooled the results using three different statistical models (fixed effects, random effects and exact method).
Results Ten studies (577 and 576 in the CPAP and NIPSV groups, respectively) met our inclusion criteria. NIPSV performed similar to CPAP in decreasing the intubation rates (OR 0.8; 95 percent CI 0.43–1.49), hospital mortality (OR 1.08; 95 percent CI 0.76–1.54) and the occurrence of myocardial infarction (OR 0.8; 95 percent CI 0.36–1.76). The results were similar when pooling the data with any of the three statistical methods and stratifying for the type of pressure therapy (fixed vs. variable) except for myocardial infarction, which was more frequent in the fixed pressure NIPSV arm (OR 5.06; 95 percent CI 1.66–15.44).
Conclusion NIPSV appears to be as safe and efficacious as CPAP, if titrated rather than fixed pressures are employed.

Keywords: acute cardiogenic pulmonary oedema, continuous positive airway pressure, intratracheal intubation, noninvasive pressure support ventilation, noninvasive ventilation, pulmonary oedema, positive-pressure respiration, respiratory insufficiency
Singapore Med J 2009; 50(6): 595-603

Tan KK, Nalachandran S, Chia KH
Correspondence: Dr Ker-Kan Tan, kerkan@gmail.com

ABSTRACT
Introduction Endovenous lasertherapy (EVLT) is one of the many minimally-invasive procedures that have been developed in recent years for the treatment of varicose veins. We present our single centre experience of 169 patients who underwent EVLT.
Methods All patients who underwent EVLT since its introduction in our institution were included in our series.
Results A total of 270 incompetent long saphenous veins in 169 patients were ablated by EVLT from February 2006 to January 2008. Bilateral EVLT was performed in 101 (59.8 percent) patients, with the remaining 68 (40.2 percent) undergoing unilateral EVLT. The mean age of the patients was 54 (range 19–78) years and there were 112 (66.3 percent) women. The majority of our patients (63.3 percent) had symptoms for more than five years. The symptoms included lower limb cramps and aches (47.9 percent) as well as lower limb swelling (16.6 percent). The median follow-up was six months. Complications from our series included numbness over the affected lower limbs (10.7 percent) and skin pigmentation (4.1 percent). Only 2.4 percent of patients had recurrence after one year.
Conclusion Early results with EVLT have been impressive, and this study has reaffirmed the safety and effectiveness of EVLT in the treatment of varicose veins.

Keywords: endovenous laser therapy, long saphenous veins, varicose veins
Singapore Med J 2009; 50(6): 591-594

Tan KBL, Yeo GSH
Correspondence: Dr George S H Yeo, mfm93b@pacific.net.sg

ABSTRACT
Introduction Turner syndrome is the most common sex chromosomal abnormality in female foetuses, and is associated with a high proportion of cardiac anomalies. The aim of this study was to look at the incidence, demographical data and epidemiological pattern of Turner syndrome in Singapore from 1999 to 2004 and to examine the birth defects associated with this condition, specifically with reference to cardiac defects.
Methods Data on Turner syndrome cases born in 1999–2004 were retrieved from the National Birth Defects Registry (NBDR) and analysed. Data on congenital cardiac defect cases notified to the NBDR in the same time period were also retrieved and compared with the Turner syndrome cases.
Results There were a total of 101 cases of Turner syndrome in the six-year period from 1999–2004, yielding an overall incidence of 0.85 per 1,000 female live births, or one in 1,180 female live births. The incidence was lowest among Indians (0.38 per 1,000) compared to Malays (0.72 per 1,000) and Chinese (0.90 per 1,000). 75 cases (74.3 percent) had the 45,X karyotype, while the other 26 cases (25.7 percent) were mosaics. The mean maternal age for 45, X was lower (32.2 years, range 22–42) compared to mosaics (34.5 years, range 27–40). 19.8 percent (20/101) were live births, 38.6 percent (39/101) were terminated pregnancies and 41.6 percent (42/101) were spontaneous miscarriages. 13.9 percent of Turner syndrome babies had cardiac defects compared to 1.2 percent in the general population (p-value is less than 0.0001). Major cardiac defects found among Turner syndrome babies compared to the general population included the coarctation of the aorta (5.9 percent compared to 0.03 percent, p-value is less than 0.0001), atrial septal defects (3.0 percent compared to 0.6 percent, p-value is 0.006), a hypoplastic left heart (2.0 percent compared to 0.05 percent, p-value is less than 0.0001), aortic hypoplasia (3.0 percent compared to 0.01 percent, p-value is less than 0.0001) and dextrocardia (1.0 percent compared to 0.02 percent, p-value is 0.0002).
Conclusion Cardiac defects, particularly left-sided ones, are significantly more common among Turner syndrome foetuses. The true incidence of this syndrome is likely to be higher than that quoted in this study, and can only be solved when a complete screening of an entire population has been performed.

Keywords: birth defects, cardiac defects, foetal defects, mosaicism, Turner syndrome
Singapore Med J 2009; 50(6): 587-590

Tan KBL, Fook-Chong SMC, Lee SL, Tan LK
Correspondence: Dr Kenny BL Tan, kennytan@nus.edu.sg

ABSTRACT
Introduction The aim of this study was to establish reference values of peak systolic blood flow velocity measurement in the foetal middle cerebral artery (MCA-PSV) in the local Asian obstetric population and to compare our reference ranges with those of previously-published studies.
Methods 329 normal pregnant women attending the outpatient antenatal clinics of the Department of Obstetrics and Gynaecology in the Singapore General Hospital underwent Doppler ultrasonography at least once between 16 and 40 weeks’ gestation. The blood flow velocity recordings from the foetal middle cerebral artery were obtained. New reference ranges were constructed by regressing each parameter on gestational age.
Results New reference ranges for foetal middle cerebral artery with gestation were constructed for an Asian population. Our reference curves were compared with that of a previously-constructed one.
Conclusion MCA-PSV increases with advancing gestational age. There appear to be differences between Asian and non-Asian reference ranges for MCA-PSV.

Keywords: anaemia, foetal anaemia, foetal middle cerebral artery, peak systolic blood flow velocity, prenatal ultrasonography
Singapore Med J 2009; 50(6): 584-586

Liang M, Lye DC, Chen MI, Chow A, Krishnan P, Seow E, Leo YS
Correspondence: Dr David C Lye, david_lye@ttsh.com.sg

ABSTRACT
Introduction Since late March 2009, a novel influenza H1N1 strain emerged in humans in Mexico and the United States. It has rapidly spread to many countries on different continents, prompting unprecedented activation of pandemic preparedness plans. Singapore has adopted a containment strategy with active screening of febrile travellers with respiratory symptoms from affected countries since April 27, 2009.
Methods All cases with new influenza A (H1N1) confirmed on polymerase chain reaction assay on combined nasal and throat swabs and who were admitted to the Communicable Disease Centre, were included in a prospective evaluation of clinical characteristics of new influenza A (H1N1).
Results From May 26 to June 3, 2009, there were ten patients with a mean age of 27.6 years, seven of whom were female. All but one travelled from the United States, six of whom travelled from New York; the last one travelled from the Philippines. Clinical illness developed within a mean of 1.4 days after arrival in Singapore, and presentation to the emergency department at a mean of 2.7 days from illness onset. Fever occurred in 90 percent, cough 70 percent, coryza 40 percent, sore throat and myalgia/arthralgia 30 percent; none had diarrhoea. The fever lasted a mean of 2.1 days. All were treated with oseltamivir. The clinical course was uncomplicated in all cases.
Conclusion Clinical features of new influenza A (H1N1) appeared mild, and ran an uncomplicated course in immunocompetent patients.

Keywords: containment, H1N1 virus, influenza A virus, pandemic, swine influenza
Singapore Med J 2009; 50(6): 581-583

Hospital Influenza Workgroup (Singapore)
Correspondence: Dr Hsu Li Yang, mdchly@nus.edu.sg

ABSTRACT
The recent emergence and global spread of a novel strain of influenza A (H1N1) virus has resulted in the first influenza pandemic of the 21st century. With its rapid spread to more than 70 countries within three months, governments are faced with the challenge of either containing or mitigating this influenza pandemic. The aim of this paper is to provide evidence-based consensus recommendations in the areas of infection control, antiviral treatment, chemoprophylaxis, antibiotic stockpiling and vaccination to guide decision-making for clinicians and administrators within the Singapore context. As the transmissibility and virulence of this new influenza A (H1N1) virus may evolve over time, we have tailored our recommendations according to several potential scenarios of viral virulence and transmissibility.

Keywords: antibiotic stockpile, chemoprophylaxis, H1N1 virus, infection control, influenza A virus, influenza epidemic, pandemic, vaccination
Singapore Med J 2009; 50(6): 567-580

Peh WCG, Ng KH
Correspondence: Prof Wilfred CG Peh, smj.editor@sma.org.sg

ABSTRACT
All persons designated as authors of a scientific manuscript should qualify for authorship, and all those who qualify should be listed. Each author should have participated sufficiently in the work to take public responsibility for appropriate portions of the content,and have made substantial intellectual contribution to the submitted manuscript. All contributors who do not meet the criteria for authorship should be listed in the acknowledgements section. Ghost authors are undesirable while professional medical writers are helpful to authors who are not native English speakers, have language difficulties, or lack training or expertise in medical writing.

Keywords: acknowledgements, authorship, ghost authors, medical writing, professional medical writers, scientific paper
Singapore Med J 2009; 50(6): 563-566

Raghavan P, Pathmanathan G, Talwar I
Correspondence: Dr Raghavan Pathmanathan, ramapithecus@usa.net

ABSTRACT
This paper surveys the opinions expressed in the recent literature on the origins of the anatomically modern Homo sapiens, and reviews the evidence from cranial and dental morphology argued by proponents of opposing views to support their case. It also critically analyses problems facing the interpretation of the evidence in arriving at a definitive conclusion to the debate.

Keywords: cranial morphology, dental morphology, Eve theory, Homo sapiens, human evolution, modern Homo sapiens, multiregional continuity, Out-of-Africa theory
Singapore Med J 2009; 50(6): 556-562