Sediment texture and nutrients of Arasalar estuary, Karaikkal, south-east coast of India.

Sediment samples were collected for texture, composition and nutrient such as organic carbon, total nitrogen and total phosphorus for a period of two years from three stations in Arasalar estuary. The sediment temperature, pH and nutrients were higher during summer season and lower during monsoon season. At station 1, sediment texture was loamy sand during summer and premonsoon season. At station 2, clay type soil was recorded. Whereas, at station 3, clay was observed in summer and premonsoon and then it shifted to sandy loam type soil during monsoon. Sediment nutrients were lower than that of values of various ecosystem of India.

Freshwater lakes--a potential source for aquaculture activities--a model study on Perumal Lake, Cuddalore, Tamil Nadu.

The freshwater Perumal lake located at Cuddalore was assessed for its suitability and potential for aquaculture practices. Various hydrobiological parameters determined reveals that the various physicochemical characteristics are with in normal range of values. The DO level, BOD and COD values determined in the lake revealed the consequences of community activities and pollution possibilities. The primary productivity data revealed maximum productivity during March which infer that the lake is unaffected by anthropogenic disturbance and community contamination. The bacterial count remained higher during the monsoon periods, which characterize profuse rainfall and storm water discharge into the lake. The microfauna includes zooplankter such as cladocerans, copepods, rotifers and ostracods. Benthos include carps, catfishes, mullets and prawns. The above study revealed that the various parameters in the lake conform to the levels suited for freshwater fish culture and represents a resource for scientific management.

Obstructive sleep apnea syndrome in obese Singapore children.

We set out to determine the prevalence of obstructive sleep apnea syndrome (OSAS) among obese Singapore school children and identify risk factors for OSAS. This study was designed as a prospective study in three phases. Parents completed a questionnaire with regards to sleep and daytime symptoms in Phase 1. Children suspected to have OSAS based on the questionnaire and all with a percent ideal body weight (IBW) >/=180 were called for clinic visits in Phase 2. All whose percent IBW >/=180 and those in whom the physicians strongly suspected OSAS were subjected to a polysomnogram in phase 3. The children were recruited from the School Health Nutritional Clinic for obese children. The investigations were carried out at Tan Tock Seng Hospital. In all, 3,671 children were screened with the questionnaire. Of these, 146 were selected to undergo polysomnography. Twenty-six had abnormal sleep studies with apnea/hypoxia indices (AHIs) >5/hr. The significant clinical feature which correlated with OSAS was sleep sitting up (P = 0.005). The risk is higher in morbidly obese (IBW >/=180), with a prevalence of 13.3% (8/60), than in less obese children (IBW <180). One in eight (12.5%) of these children was asymptomatic and would have been missed based on the questionnaire. Presence of adenotonsillar hypertrophy led to increased risk of OSAS. The prevalence of OSAS was 0.7% (26/3,671) among the obese schoolchildren in Singapore, which is similar to the prevalence reported by others. Using discriminant analysis, the estimated prevalence increased to 5.7%. In the morbidly obese (IBW >/=180), the prevalence rate is higher at 13.3%.

Idiopathic scoliosis. Prevalence and ethnic distribution in Singapore schoolchildren.

Routine examination for spinal deformity as part of a school health screening programme was introduced in Singapore in 1981. The three different ethnic groups included in the study provided figures for the prevalence of idiopathic scoliosis in an Asian population. A three-tier system of examination was used and a total of 110744 children in three age groups were studied. In those aged 6 to 7 years the prevalence was 0.12%. The prevalence in those aged 11 to 12 years was 1.7% for girls and 0.4% for boys, a ratio of 3.2 to 1. In girls aged 16 to 17 years the prevalence was 3.1%. In the latter two age groups there was a significantly higher prevalence in Chinese girls as compared with Malay and Indian girls. The optimal age for school screening seemed to be 11 to 12 years, but repeated examinations may be worthwhile.

Biological monitoring of human exposure to environmental lead in Singapore.

An epidemiological survey was conducted in 1990-91 to determine the personal and environmental factors in Singapore which may affect blood lead levels. A total of 1,408 children and adults aged from 6 months to over 50 years were interviewed and their blood samples obtained for analysis using atomic absorption spectroscopy. Overall, the geometric mean blood lead level of the population surveyed was 76.6 micrograms/l. Multivariate analyses revealed that significant variations in blood lead concentrations were related, in decreasing order of importance, to: sex, age, active and passive smoking, exposure to traffic, and exposure to recent paintwork. The consumption of alcohol and traditional medicines were found not to be significant determinants. To reduce the environmental lead problem in Singapore, unleaded petrol has been introduced and control of lead additive in paints is being considered. The national anti-smoking programme should further contribute to an overall reduction in the blood lead level of the population.

Clinical, endocrinologic, and ultrasonographic features of polycystic ovary syndrome in Singaporean adolescents.

The study sought to evaluate the clinical, endocrinologic, and ultrasonographic features in 150 Singaporean adolescent girls with polycystic ovary syndrome (PCOS) before and after treatment, which was composed primarily of a combined hormone therapy of estrogen and cyproterone acetate. The patients' ages ranged from 12 to 22 years with the majority between 15 and 18 years of age. Most of these girls were seen between their third and fifth gynecologic year. A considerable proportion of them had matured early, experiencing menarche between 9 and 12 years of age. Tanner staging was normal except for a greater proportion at higher stages for pubic and axillary hair, most likely a reflection of the substantial degree of androgenization commonly found in subjects with PCOS. All 150 patients presented with menstrual disorders including secondary amenorrhea, menarche only, anovulatory uterine bleeding, oligomenorrhea, and primary amenorrhea. The majority had normal body weight; 10% to 27% were either underweight or overweight, respectively. On ultrasound, patients presented with enlarged ovaries; enlargement was more pronounced in the right ovary with dense stroma and multiple subcapsular cysts. Many subjects had elevated androgen, luteinizing hormone (LH), and LH/ follicle-stimulating hormone (FSH) levels. Although characteristic of PCOS, FSH levels were either low or normal. Prolactin, estradiol, dehydroepiandrosterone sulfate (DHEAS), and androstenedione were generally normal. A substantial proportion of the study group had elevated cortisol levels. It was noted that adolescent girls with PCOS responded well to treatment; more than 60% showed improvement in cycle profiles following at least 1 year of treatment. Our current opinion is that adolescents with PCOS should be managed early, and that treatment should include medical correction of any hormonal or body-weight imbalance and include psychologic intervention when necessary.

A 3-year study on the effect of RGP contact lenses on myopic children.

AIM AND BACKGROUND: Recent studies in the West have shown that rigid gas-permeable (RGP) contact lenses can control the progress of myopia in children. These studies were done on Caucasian children, whose myopias are less rapidly progressive than those which we see in Singaporean children. This three-year study was started in 1993, with the following objectives: 1. To verify whether RGP contact lenses can control the progress of myopia in Singaporean children. 2. If so, to investigate the mechanism by which the lenses control myopia; whether by corneal flattening or by reducing the growth of the axial length. 3. If so, to assess if the effects are permanent, by discontinuing lens wear. MATERIALS AND METHODS: The study was carried out at the Eye Clinic of the School Health Service. Enough school children were referred to the clinic from the various schools to achieve about 100 children wearing contact lenses. Past studies showed that the drop-out rate would be 50%, as there is no cosmetic motivation in 10 year-old children to wear contact lenses. The successful wearers were those who had parental encouragement and support. RESULTS: The results show that there was a suppression of the progress of myopia in children wearing the lenses as compared to their counterparts wearing spectacles. However, only in ten eyes was there arrest of the myopia. For the lenses to be effective, they needed to be worn regularly for about eight hours a day. Reasons for the drop-outs included lack of motivation, lens intolerance and simply being too busy with the school curriculum. Discontinuance of lens wear for more than 2 months had minimal effect on the refraction, indicating that the controlling effect was not due purely to corneal change. CONCLUSION: It is recommended that more studies be done to confirm the findings of this study. Children with rapidly progressive myopia can wear rigid gas-permeable contact lenses to reduce the progression.

The incidence of IDDM in Singapore children.

OBJECTIVE: To determine the incidence of insulin dependent diabetes mellitus (IDDM) in children 0-12 years of age in Singapore, which has a population of 2.9 million. METHODS: The primary source was a 2-year phone and mail survey of doctors in the government and government restructured hospitals and the private sector. The secondary source was the membership records of the Diabetes Society of Singapore. RESULTS: Using the capture-recapture method, ascertainment was assessed to be 92.2% complete. The age standardised incidence rate was 2.46 per 100,000 children 0-12 years old, for the period 1992-1994 (95% confidence interval: 2.16-2.75). The data seemed to indicate a rising incidence of IDDM in this population, being 1.4/100,000 in 1992, 2.4/100,000 in 1993 and 3.8/100,000 in 1994. The male: female ratio is 1:1.85. There was seasonal variation with fewer cases from July to October and more from November to May. Five percent of patients had a first degree relative with IDDM. Malays appeared to have a lower incidence (1.23/100,000) compared to the Chinese (2.25/100,000) and the Indians (5.78/100,000). CONCLUSIONS: The incidence of IDDM in Singapore children is similar to that reported for Hong Kong and Japan, but higher than that for Shanghai. The female preponderance is similar to that seen in other Asian population. The data suggests a rising incidence of IDDM in Singapore and differences in incidence between the Malays, Chinese and Indians, but further observations are needed.

The epidemiology of obesity: a review.

Obesity is a major public health problem worldwide contributing to increased morbidity and mortality. There are several indices of obesity which include body mass index, waist-hip circumference ratio and skinfold thickness. The prevalence of obesity varies from 7% in France to 32.8% in Brazil. However, the comparison of obesity across different countries is difficult as there are different age structures of the population, measurement techniques are not the same and surveys may not be population-based. Trends in developed and developing countries suggest that the rates of obesity are increasing. This rising trend may be contributed by factors such as low levels of physical activity, high calorie intake and long hours of watching television. Cohort and cross-sectional studies have shown that obesity may be linked to an increased risk of coronary heart disease, hypertension, diabetes mellitus and gallstones. There is also a positive association between obesity and cancer. The mortality of obese adults, adolescents and children is higher than that of the general population. Multi-prolonged intervention strategies are needed to prevent obesity and its associated complications.

Incidence of head injury: lasting effects among college students and working adults in the general population.

224 (21%) of 1067 persons in a nonclinical population surveyed had one or more head injuries resulting in unconsciousness. They had a total of 306 head injuries with 113 (31%) of them resulting in lasting neurological effects. Both in a pilot project and in the main study, headache was the most commonly reported of an array of symptoms that are essentially a postconcussion syndrome.

A novel (TG)n(GA)m repeat polymorphism 254 bp downstream of the mast cell chymase (CMA1) gene is associated with atopic asthma and total serum IgE levels.

The gene for mast cell chymase (CMA1) is an ideal candidate for investigating genetic predisposition to atopic asthma, as it is an important mediator of inflammation and remodeling in the asthmatic lung. Various studies have examined the association between -1903 G/A polymorphism and allergic phenotypes, but inconsistent results have been obtained. We investigated the association of this SNP and a novel (TG)(n)(GA)(m) repeat polymorphism (accession no. BV210164) 254 bp downstream of the gene with asthma and its associated traits in a case-control study in two independent cohorts recruited from the Indian population. A significant association was observed for the (TG)(n)(GA)(m) repeat with asthma (p<0.05) in both the cohorts. Although no association was observed for the -1903 G/A SNP with asthma, a significant association was observed between the genotypes and serum IgE levels (p=0.003 and 0.0004 for cohort A and B). When haplotypes were compared between patients and controls, the haplotype G_43 was found at higher frequency in controls (p=0.05). Also, on comparing major haplotypes (>5%) with respect to log total serum IgE levels, a significant difference was obtained (p=0.018 and p=0.046 for cohorts A and B). These results suggest that the CMA1 gene contributes to asthma susceptibility and may be involved in regulating IgE levels in atopic asthma.

Benign familial infantile epilepsy.

We report 23 subjects with afebrile seizures. The subjects, from 11 families, were between the ages of 3 and 19 months and had normal neurodevelopmental status, a normal interictal electroencephalogram, a family history of similar seizures, and an excellent prognosis. Benign familial infantile epilepsy is a clinical syndrome that may be more common than is presently recognized.

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.

Direct spinal curvature digitization in scoliosis screening--a comparative study with Moiré contourgraphy.

The forward bending test, widely used in scoliosis screening, is associated with high false-positive rates. We postulate that direct surface measurement of the spinal curvature by digitization of the spinous processes used in combination with the forward bending test could increase the predictive value of detecting scoliosis without sacrificing sensitivity. Sixty consecutive patients referred from a school screening program were included in this study. All had moiré contourgraphy, spinous process digitization, and erect frontal radiographs of the spine. The number of false positives from the forward bending test was 35. Moiré contourgraphy did not reduce the number of false positives significantly. A posterior spinal deformity of 10 degrees or more predicted scoliosis in all patients, with 15 false-positive readings. Direct measurement of the spinal curvature by spinous process digitization can be an effective second-stage screening tool for scoliosis in centers where all the screened positives are referred to a single center.

Social class distribution of obese Chinese children.

Four hundred and eighty four obese Chinese children who were defined obese by a relative weight of more than 120% of standard weight-for-height had their social status evaluated. The social class of each child was arbitrarily determined according to the father's occupation. The distribution of obese children in various social levels was compared with that of the working population in Singapore. Significantly greater proportions of children were in the upper and middle social classes compared with the general working population. Such trends may be related to the increased affluence of the society and the accompanying changes in life-styles and eating habits, and will influence measures in health education and control of childhood obesity in the future.