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Biomedical subjects

S C Quek

Publications and source records attributed to S C Quek.

At least 19 recordsLinked to original sources
PubMed2006

The effects of three factor VII polymorphisms on factor VII coagulant levels in healthy Singaporean Chinese, Malay and Indian newborns.

Factor VII (FVII) is an independent risk factor for coronary artery disease. Three polymorphisms of the factor VII gene (F7) were studied in a group of healthy newborns comprising 561 Chinese, 398 Malays and 226 Asian Indians from Singapore. The allele frequencies of 3 polymorphisms (R353Q, Promoter 0/10bp Del/Ins and Intron 7) in the FVII gene were ascertained through genotyping by polymerase chain reaction and restriction digestion of amplified fragments. In Chinese the minor allele frequencies are Q: 0.04, Ins: 0.03, R7: 0.44; Malays, Q: 0.06, Ins: 0.10, R7: 0.41; and Indians, Q: 0.25, Ins: 0.23, R7: 0.43. Strong linkage disequilibrium (Delta > 0.7) is observed between the 0/10 bp and the R353Q sites in all ethnic groups. We conclude that: (i) the prevalence of the minor Q and Ins alleles of the R353Q and 0/10 bp polymorphisms are significantly higher in the Indian newborns than the Chinese and Malays; (ii) the Q allele is significantly associated (p = 0.01) with a lower plasma FVII coagulant level in the Indian and Malay neonates; and this polymorphism explains up to 3.8% of the variance in FVII coagulant levels; (iii) there is no significant difference in allele frequencies of the three polymorphisms between neonates with and without family histories of CAD.

Antigens↗
PubMed2004

Immunosuppressive therapy in acute myocarditis: an 18 year systematic review.

BACKGROUND: Immunosuppressive therapy is reportedly ineffective in adults with acute myocarditis. AIMS: To systematically review the impact of immunosuppressive therapy on the outcome of acute myocarditis in children. METHODS: A literature search for articles published from 1984 to 2003 was conducted with the following keywords: myocarditis, dilated cardiomyopathy, and immunosuppression. The relevant studies were systematically reviewed and comparison of treatment effect was made by calculating the odds ratio (OR) and confidence interval (CI) using the exact method based on the exact discrete reference distribution. RESULTS: Of the 1470 articles found, only nine studies were eligible. The odds for improvement with immunosuppression was between 4.33 (95% CI 0.52 to 52.23) and 2.7 (95% CI 0.59 to 14.21). Addition of a second immunosuppressive agent to prednisolone only proved effective in one randomised controlled trial (OR 0.09, 95% CI 0.01 to 0.52). Heterogeneity of these studies precluded pooled odds ratio. CONCLUSION: Current data suggest that immunosuppressive therapy does not significantly improve outcomes in children with acute myocarditis and there is insufficient evidence for its routine use. However, statistical power to detect a significant difference in the treatment effect may be limited because of the small number of subjects. This, together with problems of diagnosis, varying treatment practices, and a relative lack of evidence based guidelines would support efforts for a large multicentre, randomised controlled trial to better define the role of immunosuppression in acute myocarditis.

Acute Disease↗
PubMed2001

Liver transplantation in a child with severe hypercholesterolaemia in Alagille syndrome.

INTRODUCTION: Liver transplantation is a curative treatment modality in children with end stage liver disease in Alagille syndrome. CLINICAL PICTURE: We report a 3-year-old child with this condition who had severe hypercholesterolaemia, pruritus and extensive xanthomatosis. TREATMENT: Liver transplantation was performed in this patient. OUTCOME: He recovered well with normalisation of his lipid profile. This procedure also resulted in resolution of the disfiguring xanthomatosis.

Alagille Syndrome↗
PubMed2001

A case series of six children with primary pulmonary hypertension.

INTRODUCTION: Primary pulmonary hypertension is an uncommon but serious disease in children. Management is difficult despite recent advances in pharmacotherapy. CLINICAL PICTURE: We reviewed patients with this condition with respect to their presenting symptoms, investigations, treatment and outcome. TREATMENT: These children were treated with individualised combinations of oxygen, diuretics and calcium antagonists. OUTCOME: In our follow-up of 5 children, 4 had died. CONCLUSION: This condition is irreversible and progressive with a high mortality rate. A better understanding of, and research into, the pathogenesis would hopefully lead to the formulation of improved therapeutic strategies for this condition.

Adolescent↗
PubMed2000

Abdominal coarctation and Alagille syndrome.

Structural cardiac defects such as peripheral pulmonary stenosis are well-described in Alagille syndrome (AS), which is transmitted in an autosomal dominant inheritance. The genetic defect, with incomplete penetrance and variable expression, is localized to the short arm of chromosome 20. Abdominal coarctation is an uncommon congenital anomaly, with a spectrum of symptoms that may range from hypertension, intermittent claudication to abdominal pain. The association of abdominal coarctation with AS is rarely described. We report such a patient who also had aberrations of the visceral vascular supply involving the celiac, splenic, and superior mesenteric arteries. The indications to treat the coarctation, and in the context of a patient with AS, in whom liver transplantation may be contemplated at some stage, merit discussion.

Alagille Syndrome↗
PubMed2000

Initial experience of radiofrequency catheter ablation of supraventricular tachycardia in paediatric patients.

INTRODUCTION: The management of supraventricular tachycardia (SVT) in paediatric patients until recently has frequently been pharmacologic therapy, but this approach suffers from the drawbacks of treatment failure, development of drug intolerance and/or side-effects. AIM: In keeping with recent advances in paediatric cardiology, we share our experience with radiofrequency catheter ablation as an alternative and definitive modality of therapy. MATERIALS AND METHOD: 4 young patients with recurrent SVT underwent electrophysiologic study followed by radiofrequency ablation of the accessory pathways. RESULTS: Resolution of symptoms was achieved in all patients and no major complication was encountered. CONCLUSIONS: The ability to ablate permanently the reentrant circuit responsible for SVT has now permitted cure by non-surgical means, and is an important alternative to drug therapy in the management of SVT in children.

Adolescent↗
PubMed2000

A case report on the perinatal management of a 30-week preterm baby with congenital complete heart block.

INTRODUCTION: Congenital complete heart block is an uncommon condition in the newborn, but is known to occur with maternal systemic lupus erythematosus. CLINICAL PICTURE: This paper presents one such baby with complete heart block who was born premature (after a gestation of 30 weeks) and weighing 759 g. TREATMENT: Continuous isoprnaline infusion was initially used to support the baby while her other neonatal problems were treated. A Medtronics VV1 pacemaker was subsequently inserted to maintain a heart rate that would be more physiologically acceptable for the patient. OUTCOME: This baby is currently thriving well, having been followed up for one year. CONCLUSIONS: The management issues, encompassing maternal and neonatal problems, and a review of current literature on this condition are discussed.

Adult↗
PubMed1999

Outcome of surgical closure of doubly committed subarterial ventricular septal defect.

BACKGROUND: From 1986 to March 1997, 128 patients diagnosed to have doubly committed subarterial ventricular septal defects (VSD) were reviewed. Patients with aortic regurgitation (AR), and aortic valve (AV) deformity or a large left-to-right shunt across the VSD were offered operation. Forty-five patients (27 men, 18 women) agreed to surgical closure of their VSDs. METHODS: Thirty-eight patients had VSD closure alone, and 7 had an additional AV repair. Other associated defects corrected at operation were closure of atrial septal defects, closure of other ventricular septal defects, ligation of patent ductus arteriosus, and repair of ruptured sinus Valsalva aneurysm. RESULTS: There was no mortality nor major morbidity associated with operation. In the 26 patients with AR and AV deformity preoperatively, valve repair was performed in 6 patients. The condition of AR improved in 4, and remained unchanged in 22 patients. In the 10 patients with a deformity of the AV and no AR preoperatively, the condition remained unchanged in 5 patients, from whom 1 had valve operation, but progressed in 5 patients postoperatively at a mean follow-up of 6.4 years. In 9 patients with no deformity of the AV and no AR preoperatively, there was no postoperative AR and no progress of valve deformity. CONCLUSIONS: Excellent results were obtained with VSD closure and AV repair. Surgical closure of VSD, if performed before the onset of AV deformity, may prevent progressive AR. If AV repair is performed after the onset of AV deformity, progressive AR may not always be prevented.

Adolescent↗
PubMed1999

Bidirectional cavopulmonary anastomosis.

The Fontan operation has been used to palliate patients with a functional single ventricle. In many such patients the operative risk for a Fontan procedure is high. The bidirectional cavopulmonary anastomosis (BCPA) is a useful intermediate palliative procedure before Fontan correction. It may reduce the deleterious sequelae of chronic hypoxaemia and long-term ventricular overload, thus yielding a more suitable Fontan candidate. We reviewed our experience of 9 patients with univentricular hearts who were at the time of the BCPA not considered suitable candidates for conventional Fontan operation. Two patients had double inlet right ventricle (DIRV) with pulmonary stenosis (PS) and ventricular septal defect (VSD), 2 had univentricular heart, 4 had tricuspid atresia (TA) and hypoplastic right ventricle (RV), 1 patient had atrioventricular septal defect (AVSD) with double outlet right ventricle (DORV) with hypoplastic RV. Two of the 9 patients had bilateral superior vena cavae. All except one had undergone prior palliative operations. The mean age at BCPA was 4.7 years (range 1.5 years to 6 years) and the mean weight at surgery was 15 kg (range 7 to 22 kg). There were no operative deaths. The mean hospitalization stay was 8.5 days (range 5 to 13 days) with a mean follow up of 14 months. Median oxygen saturation improved from 78.7 +/- 6.3% to 85.9 +/- 3.9%. The BCPA is a useful palliative procedure to stage Fontan type reconstruction in selected patients with univentricular hearts.

Anastomosis, Surgical↗