Variations in ocular biometry in an adult Chinese population in Singapore: the Tanjong Pagar Survey.
(49/1776)
PURPOSE: To describe the variation in ocular biometry in adult Chinese individuals in Singapore. METHODS: This study was a population-based, cross-sectional survey of adult Chinese persons aged 40 to 81 years residing in Tanjong Pagar district, Singapore. Axial ocular dimensions, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and vitreous chamber depth (VCD) were measured using an A-scan ultrasound device. Corneal curvature (CC) and noncycloplegic refraction were measured with an autorefractor, with refraction further refined subjectively. Lens nuclear opacity (NO) was graded clinically using the modified Lens Opacity Classification System III (LOCS III) score. RESULTS: A total of 1717 subjects were eligible for the survey, of whom 1232 (71.8%) participated. Biometric and refraction data were available for 1004 (58.5%) phakic subjects. The AL, ACD, LT, VCD, CC, and LOCS III scores were 23.23 +/- 1.17 mm, 2.90 +/- 0.44 mm, 4.75 +/- 0.47 mm, 15.58 +/- 1.11 mm, 7.65 +/- 0.27 mm, and 3.2 +/- 0.9 (mean +/- SD), respectively. On average, people aged 40 to 49 years, when compared with those 70 to 81 years, had longer ALs (mean difference, +0.58 mm), deeper ACDs (+0.52 mm), longer VCDs (+0.72 mm), but thinner lenses (-0.70 mm) and less severe NO (-1.7 LOCS III score). CCs did not vary significantly with age. After controlling for age, women had shorter ALs and VCDs, shallower ACDs, but thicker lenses and steeper CCs than men. The variation in noncycloplegic refraction with age was nonlinear. Among people aged 40 to 59 years, a higher prevalence of hyperopia was seen in older compared with younger persons (on average, a difference of +1.3 D for every 10-year difference in age, P: < 0.001), explained principally by shorter AL (and VCD) in older persons. Among those 60 to 81 years, this pattern was not obvious (a difference of -0.03 D for every 10-year difference in age, P: = 0.12), as NO became an additional determinant of refraction, with greater degrees of NO in older person's driving refraction in the "minus" direction. CONCLUSIONS: Ocular dimensions vary with age and gender in adult Chinese persons in Singapore. The variation in noncycloplegic refraction in people 40 years and older may be explained by differences in axial lengths (principally vitreous chamber depths) between older and younger persons and, from 60 years onwards, differences in lens nuclear opacification as well. (+info)
Genetic, dietary, and other lifestyle determinants of plasma homocysteine concentrations in middle-aged and older Chinese men and women in Singapore.
(50/1776)
BACKGROUND: Epidemiologic studies have identified the plasma homocysteine concentration as a risk factor for atherothrombotic vascular disease. There is little information on the distributions and determinants of homocysteine concentrations in Asian populations. OBJECTIVE: The present study was designed to examine the relations between genetic and lifestyle factors and plasma homocysteine concentrations among Chinese in Singapore. DESIGN: Plasma total homocysteine, folate, vitamin B-12, and vitamin B-6 concentrations and genetic variation at the methylenetetrahydrofolate reductase (MTHFR) locus were measured in 486 Chinese men and women aged 45-74 y in Singapore. Data on dietary and other lifestyle factors were collected in face-to-face interviews. RESULTS: Men had higher plasma concentrations of total homocysteine than women (P = 0.0001). Age was positively associated with plasma homocysteine in both sexes (P for trend = 0.0001). Plasma concentrations of folate, vitamin B-12, and vitamin B-6 were inversely associated with homocysteine concentrations. Among individuals with low plasma folate, those possessing 2 copies of MTHFR mutant alleles had significantly higher homocysteine concentrations than did those with > or = 1 copy of the wild-type allele. Cigarette smoking, daily coffee consumption, and physical inactivity were positively related to plasma homocysteine concentrations in both sexes (P < 0.05). However, these associations disappeared after adjustment for plasma folate concentrations. CONCLUSIONS: Age, sex, plasma folate, vitamin B-12 and B-6 concentrations, and MTHFR genotype are independent determinants of plasma homocysteine in middle-aged and older Chinese in Singapore. These factors combined could account for up to 40% of the total variation in homocysteine concentrations in this Asian population. (+info)
Singapore focuses its life science strategy on humans.
(51/1776)
The tiny island has invested heavily in life sciences as a linchpin of its future economy. But initial enthusiasm for a broad-based approach has switched to a focus on human healthcare, reports Kenneth Lee. (+info)
Determination of the complete nucleotide sequences of RNA1 and RNA2 from greasy grouper (Epinephelus tauvina) nervous necrosis virus, Singapore strain.
(52/1776)
The complete nucleotide sequences of RNA1 and RNA2 from greasy grouper (Epinephelus tauvina) nervous necrosis virus (GGNNV), Singapore strain, were determined. 5' RACE and RNA ligation were used to obtain the complete nucleotide sequences of the 5' and 3' non-coding regions (NCRs). GGNNV RNA1 was determined to be 3103 nt long, containing an ORF of 982 aa, while GGNNV RNA2 was determined to be 1433 nt long, containing an ORF of 338 aa. Both GGNNV RNAs are longer than those of other published betanodavirus sequences and the additional nucleotides were located within the NCRs. Analysis of GGNNV RNA2 revealed that it is closely related to red-spotted grouper nervous necrosis virus and that both grouper viruses share the same neutralization epitope. Predicted domains for six RNA-dependent RNA polymerase motifs and two putative ORFs (proteins B1 and B2) were confirmed by sequence analysis of GGNNV RNA1. (+info)
Characteristics of cataracts in the Chinese Singaporean.
(53/1776)
PURPOSE: To conduct an epidemiological survey of cataracts and examine the characteristics of lens opacities in Chinese Singaporeans. The results are then compared with those from two similar surveys previously done in Japan in Noto Area, Honshu, and Amami, Kyushu, respectively. SUBJECTS AND METHODS: 468 subjects of > or = 50 years of age, who responded to the invitation to participate, were examined. Examination principally included photo-documentation of the anterior and posterior segments of both eyes. Evaluation and grading of lens opacities were done using graphical analysis of Scheimpflug and retro-illumination images. Inter-group comparisons were based on statistical analysis of cataract prevalence and distribution. RESULTS: The prevalence of clear lenses decreased with aging with no significant difference between males and females--a finding common to Singapore and the two Japanese study groups. The prevalence of cataracts (or lens opacities of Grade II and above) in 60-79 year-old Singapore subjects was significantly higher than Noto and Amami subjects in the same age group. Further, cortical opacity was the main type in Singapore subjects in their 50s and which was significantly higher than Noto subjects of the same age group. In all age groups, the distribution and prevalence of both nuclear and subcapsular types in the Singapore group were higher than the two Japanese study groups. CONCLUSIONS: Cataracts in Chinese Singaporeans are characterized by a high prevalence of nuclear opacities which was generally seen in tropics and sub-tropics. Our study also suggested the involvement of solar-UV in cortical cataracts as well as that of additional risk factors, such as environmental temperature and race, in nuclear and subcapsular cataract formation. (+info)
Cytochrome P4501A2 (CYP1A2) activity and lung cancer risk: a preliminary study among Chinese women in Singapore.
(54/1776)
There is increasing evidence for the role of heterocyclic and other arylamines in carcinogenesis, including lung carcinogenesis. Chinese women have a high rate of lung cancer despite a low smoking prevalence, and studies in this population may provide useful information on risk factors other than smoking. Hepatic CYP1A2 and NAT2 are involved in the metabolism of carcinogenic arylamines, and NAT2 also catalyzes the detoxification pathway for these compounds. In this study, we examined the effect of CYP1A2 activity using a urinary caffeine metabolic ratio assay for 54 Chinese women with newly diagnosed lung cancer (including 28 adenocarcinomas) and 174 hospital controls. Among them, NAT2 genotype was available for 47 cases and 98 controls. There was no effect of CYP1A2 activity on overall risk of lung cancer in the study population [odds ratio (OR) 0.8, 95% confidence interval (CI) 0.4-1.6, adjusted for age at diagnosis, smoking and cruciferous vegetable intake]. For adenocarcinomas, the OR was 1.5, 95% CI 0.6-3.4. After further adjustment for NAT2 acetylator genotype, the OR for adenocarcinoma was 1.8 (95% CI 0.7-4.8). When the combined NAT2/CYP1A2 status was examined, women with slow NAT2 and rapid CYP1A2 activity were at highest risk (adjusted OR 6.9, 95% CI 1.3-37.6) relative to women with rapid NAT2 and slow CYP1A2 activity, for lung adenocarcinoma. While larger studies are needed to confirm or refute these results, they are consistent with a role for heterocyclic arylamines in lung carcinogenesis in this primarily non-smoking population. (+info)
Ethnic differences in anthropometry among adult Singaporean Chinese, Malays and Indians, and their effects on lung volumes.
(55/1776)
When standing height (StndHt) cannot be assessed, arm span (AS) or sitting height (SitHt) has been used as surrogate variables for prediction of StndHt in adult caucasians and blacks. We examined (1) the relationship between StndHt, AS and SitHt among adult Chinese, Malays and Indians; and (2) whether anthropometry could explain the ethnic differences in lung volumes (as StndHt-adjusted lung volumes are known to differ significantly: Chinese > Malays > Indians). We recruited 1250 consecutive outpatients aged 20-90 years. Prediction equations of StndHt (with AS, SitHt, weight, age as predictors) for each subgroup of race and sex were formulated with multiple linear regressions. Equations with both AS and SitHt as predictors had the best goodness of fit (SEE = 2.37-2.85 cm, adjusted R2 = 0.67-0.87), as compared to equations with either AS (SEE = 3.00-3.91 cm, adjusted R2 = 0.58-0.80) or SitHt alone (SEE = 3.48-4.00 cm, adjusted R2 = 0.45-0.76). GLM general factorial analyses found that age- and weight-adjusted SitHt-to-StndHt ratios differed significantly among Chinese (0.539), Malays (0.529) and Indians (0.518). This paralleled the ethnic differences in lung volumes. The equations with both AS and SitHt as predictors provide the most accurate estimate of StndHt. Ethnic differences in upper body segment length may explain in part the lung volume differences. (+info)
The relationship between ocular dimensions and refraction with adult stature: the Tanjong Pagar Survey.
(56/1776)
PURPOSE: To describe the association of ocular dimensions and refraction with adult stature. METHODS: This was a population-based cross-sectional survey of adult Chinese aged 40 to 81 years residing in the Tanjong Pagar district in SINGAPORE: As part of the examination, ocular dimensions, including axial length, anterior chamber depth, lens thickness, and vitreous chamber depth, were measured using an A-mode ultrasound device. Corneal radius and refraction were determined with an autorefractor, with refraction further refined subjectively. Height (in meters) and weight (in kilograms) were measured using a standardized protocol, and body mass index (BMI) was calculated as weight divided by the square of the height (kilograms per square meter). RESULTS: Data on ocular biometry, refraction, height, and weight were available on 951 (55.4%) participants with phakic eyes. After controlling for age, sex, education, occupation, housing type, income, and weight, it was found that taller persons were more likely to have longer axial lengths (+0.23 mm longer axial length, for every 0.10 m difference in height), deeper anterior chambers (+0.07 mm), thinner lenses (-0.09 mm), longer vitreous chambers (+0.26 mm), and flatter corneas (+0.09 mm longer corneal radius), although refractions were similar. In contrast, heavier persons tended to have more hyperopic refractions (+0.22 D for every 10 kg difference in weight, +0.56 D for every 10 kg/m(2) difference in BMI) but similar ocular dimensions. CONCLUSIONS: Adult height is independently related to ocular dimensions, but does not appear to influence refraction. Thus, although taller persons are more likely to have longer globes, they also tend to have deeper anterior chambers, thinner lenses, and flatter corneas. Conversely, weight is independently related to refraction, although the exact biometric component responsible for this association is not apparent. (+info)