Search PubMed⌕ Search

Biomedical subjects

J S Tay

Publications and source records attributed to J S Tay.

At least 73 records · Page 4Linked to original sources
PubMed1991

Assessment of ventricular septal defect by colour flow mapping.

The purpose of this study was to evaluate the usefulness of colour flow mapping (CFM) in the diagnosis and classification of congenital ventricular septal defect (VSD) and in the confirmation of spontaneous and surgical closure. Between August 1988 and March 1990, a total of 102 patients with isolated VSD (82 preoperative and 20 postoperative), age ranging from one day to 14 years, were subjected to 176 echocardiographic examinations. Sequential cross sectional imaging and CFM were the main modalities of assessment with conventional Doppler interrogation for quantitative measurements. In the preoperative group, there were 56 (68.3%) perimembranous (pm) VSD, 14 (17.1%) muscular (m) VSD and 12 (14.6%) doubly committed subarterial (dcsa) VSD. Ventricular septal defect was detected by CFM only in 88.9% of m/VSD, 57.6% of dcsa/VSD and 11.8% of pm/VSD (p less than 0.01). Spontaneous closure rate was highest in m/VSD (28.6%) followed by pm/VSD (8.9%) (p = 0.05). None of the dcsa/VSD closed as assessed by CFM. In the postoperative group, CFM served to quickly confirm complete closure without residual left to right shunt in 20 patients. In addition, CFM was useful in the assessment of haemodynamics and flow directed Doppler interrogation. Hence, CFM is a useful adjunct to cross sectional imaging in the assessment of children with isolated VSD.

Adolescent↗
PubMed1990

Genetic studies among the Nagas and Hmars of eastern India.

A total of 148 Nagas (65 urban and 83 rural) and 81 Hmars from northeastern India were tested for 15 blood genetic markers. Both the Nagas and Hmars lacked haemoglobin variants and G6PD deficiency and had a high frequency of PGDC. This may be attributed to selective pressures operating at these loci. Genetic distance estimates using 41 alleles at 11 polymorphic loci showed appreciable heterogeneity between the urban and rural Nagas that were in line with the differences in gene frequencies. Considerable genetic admixture of the urban Nagas from the Hmar and other neighbouring populations is evident. The Nagas were found to be quite distant from the mainland Han Chinese and Malays as well as from the Bengalis and Oraons. However, they appear to be related to the Hmar and Lepcha. Evidence supporting the ethnohistoric origin of the Nagas from China or the South Seas is lacking.

Alleles↗
PubMed1990

Sonographic screening for renal tract anomalies associated with congenital heart disease.

The incidence of structural renal tract abnormalities in 109 children with documented congenital heart disease (CHD) was studied using real-time sonography. In these children, 11.9% had associated urologic anomalies, which included hydronephrosis, duplication, ectopia, agenesis, and dysplasia of kidneys. Children with associated extracardiac anomalies had a significantly higher incidence of renal tract anomalies (39.1%) compared to those with isolated CHD (4.7%). Therefore, sonographic screening of the renal tract should be performed routinely in patients with CHD, especially in those with multiple congenital defects.

Abnormalities, Multiple↗
PubMed1990

Acute glomerulonephritis--changing patterns in Singapore children.

This study compared the pattern of acute glomerulonephritis (AGN), a disease known to be influenced by socioeconomic and environmental factors, in children 12 years and under, for the years 1971 and 1985. All children admitted to the four major paediatric departments with haematuria and at least two of the following (oedema, hypertension or oliguria) had an initial diagnosis of AGN. A sample population from one unit from 1980 to 1984 showed that over 70% of these children had evidence of a post-streptococcal aetiology. In 1971, 411 children were admitted with AGN, as compared with only 58 in 1985. The age-sex-race standardized rates for 1971 and 1985 were 0.632 and 0.023/1,000 children 12 years and under, respectively (P less than 0.001). The mean age of presentation was lower in 1971. Over this period, Singapore saw a threefold rise in the gross national product, accompanied by rapid urbanization. On analysis of the housing pattern, only 31% of the children lived in high-rise apartments in 1971, in contrast with 86% in 1985 (P less than 0.001). The majority of non-apartment dwellers had homes in rural districts. From an epidemiological perspective, factors which could have led to the highly significant decline in prevalence of AGN in Singapore children included improvement in the socioeconomic status and health care system, and urbanization of the country.

Acute Disease↗
PubMed1990

The distribution of some serum protein and red cell enzyme polymorphisms in the Koch ethnic group of West Bengal, India.

Three populations (Poliya, Deshi, and Tiyor) of the Koch ethnic group have been studied for the distribution of three serum protein and four red cell enzyme polymorphisms. There was no significant difference in the allelic frequencies of these systems in the three populations of the Koch ethnic group. The overall gene frequencies were as follows: Hp1, 0.21; Gc1F, 0.34; Gc1S, 0.36; Gc2, 0.30; TfC1, 0.66; TfC2, 0.26; TfC3, 0.001; TfD, 0.06; GLO1, 0.21; PGI2, 0.04; AK2, 0.01; PGM1+, 0.80; PGM1-, 0.06; PGM2+, 0.11 and PGM2-, 0.02. The phenotypic distribution at all the loci was at Hardy-Weinberg equilibrium.

Adenylate Kinase↗
PubMed1990

Transferrin subtypes and spontaneous abortion in a Chinese population.

A series of Chinese newborns of consecutive normal vaginal deliveries were investigated for the distribution of serum transferrin subtypes by polyacrylamide gel iso-electric focusing at pH 3.5-9.5. Newborns whose mothers had a history of previous spontaneous abortion (n = 189) had a significantly higher frequency of the C2 variant and the C2 gene compared to those (n = 864) without a history of spontaneous abortion. There was no significant difference in the frequency of transferrin alleles between newborns with normal and low birth weight (n = 147).

Abortion, Habitual↗
PubMed1990

Restriction fragment length polymorphism (RFLP) at the DNF15S2 locus in three ethnic groups of Singapore.

Three different ethnic groups from Singapore comprising 79 Chinese, 34 Malays and 23 Indians of Dravidian origin, were investigated for the HindIII RFLP at the DNF15S2 locus. The three populations had very similar allele frequencies and the frequency of rarer(S) allele was significantly (p less than 0.01) lower (0.21) in these ethnic groups compared to that in Caucasians (0.41). The phenotypic distributions were at Hardy-Weinberg equilibrium.

China↗
PubMed1990

Kawasaki disease. Some recent studies on pathogenetic mechanisms.

Kawasaki disease is diagnosed with increasing frequency in countries outside Japan. It has attracted widespread interest because of the possibility of coronary aneurysms and sudden death in the patients. While advances in treatment have been achieved, and in particular, the value of intravenous gamma-globulin therapy, the etiology of the disease is still uncertain. This paper is a brief review of some recent studies which have shed light on the pathogenesis of the disease. Studies from animal models and information from immunological abnormalities, platelet immune complex interactions and coagulation abnormalities point to the importance of immunoregulatory mechanisms in pathogenesis. Evidence so far do not support a major role for genetic factors.

Animals↗
PubMed1990

Percutaneous transluminal balloon valvuloplasty: the treatment of choice for congenital valvar pulmonary stenosis.

Forty-eight children with suspected isolated pulmonary valvar stenosis were evaluated clinically and echocardiographically between January 1987 and December 1988. Fourteen patients with significant transpulmonary peak systolic pressure gradient greater than 30 mmHg on continuous-wave Doppler interrogation were subjected to right heart catheterisation. Percutaneous transluminal balloon valvuloplasty was performed in 11 of these patients with peak systolic pressure gradient than 40 mmHg across the pulmonary valve at cardiac catheterisation. Satisfactory reduction of systolic right ventricular pressure (110 +/- 43 to 46 +/- 17 mmHg, p less than 0.001) and peak systolic pressure gradient across pulmonary valve (92 +/- 44 to 27 +/- 16 mmHg, p less than 0.001), were achieved in all cases. The reduction of peak systolic pressure gradient (64 +/- 37 mmHg, range = 29-158 mmHg), was positively correlated with the initial right ventricular systolic pressure (r = 0.92, p less than 0.0002). There was no significant complication in this series and all patients were discharged the day after the procedure. Percutaneous transluminal balloon valvuloplasty is effective and safe. It should be the treatment of choice for significant valvar pulmonary stenosis in children.

Cardiac Catheterization↗
PubMed1989

Inbreeding effects on average heterozygosity in the Sudan.

In the first series, the average heterozygosity based on ten polymorphic loci (Rhesus, MN, P, and Kell blood groups; haemoglobin; serum haptoglobin; transferrin; red cell acid phosphatase, phosphoglucomutase-1 and glyoxalase-1) was determined among the offspring of unrelated (n = 328) and related (first-cousin) matings (n = 466) in the Sudan. The estimated average heterozygosity was found to be the same in the offspring of the first-cousin and unrelated parents (0.3628 +/- 0.0584 and 0.3697 +/- 0.0581, respectively). In the second series, the average heterozygosity at five polymorphic loci (Rhesus blood group, haemoglobin, serum haptoglobin and transferrin and red cell acid phosphatase) was estimated in several tribes with variable levels of inbreeding coefficients. The estimated average heterozygosity varied from 0.14 +/- 0.09 to 0.37 +/- 0.08 in different tribes with varying degrees of inbreeding coefficients (alpha x 10(5) of 967-3,904). However there was no significant correlation between the level of parental inbreeding with either average heterozygosity or deviation from the Hardy-Weinberg equilibrium in the offspring.

Blood Group Antigens↗
PubMed1989

Kawasaki syndrome in Chinese children.

A retrospective analysis of the clinical features and outcome of 39 Chinese children with Kawasaki syndrome was made. The mean age of onset was 2.7 years (range: 0.2-13 years). The male:female ratio was 2.9:1. One child presented with nephrotic syndrome. This renal manifestation has not been described in Kawasaki disease. Ten (32%) out of 31 patients were found to have coronary aneurysms by cross-sectional echocardiography. The only significant risk factor detected in this group of patients was anaemia (P less than 0.007). There was one (2.5%) death from acute myocardial infarction and the rest of the patients were clinically well with a mean follow-up period of 1 year (mean: 5-40 days). This study indicates that there is a high incidence of coronary aneurysm complicating Kawasaki syndrome in Chinese comparable with that reported in Japanese children.

Child, Preschool↗
PubMed1989

Detection of cardiac problems among school children by health screening.

A study was undertaken to assess the types of cardiac diseases and dysrhythmias in a healthy population of 651,794 school children who underwent general health screening between January 1981 to December 1986. Congenital heart lesions were diagnosed in 1159 (0.18 per cent), the majority being mitral valve prolapse (MVP; 0.08 per cent), small ventricular septal defects (VSD; 0.04 per cent), mild pulmonary stenosis (PS; 0.03 per cent), and small atrial septal defects (ASD; 0.02 per cent). Other lesions detected were patent ductus arteriosus (PDA), coarctation of aorta (CoA), Fallot's Tetralogy (FT) and total anomalous pulmonary venous drainage (TAPVD). Of these, five had surgical closure of ASD, eight and ligation of PDA, and one had correction for TAPVD. Cardiac dysrhythmias were seen in 350 patients; consisting of premature ventricular contractions (PVC) in 186, right bundle branch block (RBBB) in 132, atrial ectopics (AE) in 17, sinus node dysfunction in five, atrioventricular (AV) block in seven, Wolff-Parkinson-White (WPW) syndrome in two, and paroxysmal atrial tachycardia (PAT) in one boy. Associated congenital heart lesions were found in 110 patients. The cardiac screening programme has resulted in a significant detection of cardiac abnormalities among apparently healthy school children. Early detection of cardiac disease has resulted in early remedial measures to be taken and thus improved cardiological care.

Arrhythmias, Cardiac↗
PubMed1989

Nephrotic syndrome in Kawasaki disease.

Renal manifestations in Kawasaki disease are rare, and nephrotic syndrome in this disorder has not been described previously. We report a 3 month old infant with Kawasaki disease, presenting with nephrotic syndrome which responded to steroid therapy. The patient, however, developed coronary aneurysms and died of acute myocardial infarction.

Acute Disease↗
PubMed1989

Distribution of plasma alpha-1-B-glycoprotein phenotypes in several Mongoloid populations of East Asia.

The distribution of plasma alpha 1B-glycoprotein (alpha 1B) phenotypes was determined by a simple method of two-dimensional electrophoresis followed by protein staining in a group of 1,154 individuals from 8 Mongoloid populations of East Asia. The sample comprised 581 Chinese from different localities (Singapore: 204; Taiwan: 150; Fujien and Hopeh provinces of eastern China: 146 and 81), 155 Koreans, 155 Filipinos, 152 Thais and 111 Malays. Altogether, 6 different alpha 1B phenotypes (1-1, 1-2, 2-2, 1-3, 2-3, and 1-6) were observed. The alpha 1B allele frequencies were very similar in all of the populations. The frequency of A1B*1 varied from 0.89 to 0.91 and that of A1B*2 from 0.08 to 0.10. The A1B*3 allele, reported previously only in American blacks, was observed with a frequency range of 0.003-0.01 in 3 of the Chinese populations, in Koreans and in Malays. A new alpha 1B allele (A1B*6) was observed in 2 Chinese individuals.

Adult↗
PubMed1989

Cardiac arrhythmias in paediatric practice.

Clinical data of patients with cardiac arrhythmias managed between May 1986 and March 1988 were reviewed to determine their mode of presentation and clinical course. Of the 5,768 admissions, 62 (1.07%) patients had arrhythmias. During the same period, 21 patients were managed as outpatients with 13 being new referrals. Thirty-eight patients had undergone corrective cardiac procedures, 8 others had congenital heart lesions, 3 were associated with acquired cardiac pathology and the remaining had isolated arrhythmias. The cardiac arrhythmias were: right bundle branch block 36, premature atrial and ventricular contractions 15, supraventricular tachycardia (SVT) 15, atrioventricular (AV) block 7, sinus bradycardia 3, atrial fibrillation 2, ventricular tachycardia and fibrillation 2, Wolff-Parkinson-White syndrome without SVT 2, bradytachyarrhythmia 1. There were 3 patients with foetal SVT, one persisting till day 1. High grade AV block occurred in 2 patients post-surgically and needed pacing. Only 2 others were symptomatic. Other than the 38 patients who underwent corrective procedures (2 had balloon valvuloplasty for pulmonary stenosis), 8 others had structural heart disease. There was 1 sudden death and 5 died from their primary heart disease.

Adolescent↗