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Biomedical subjects

D Koh

Publications and source records attributed to D Koh.

At least 37 records · Page 2Linked to original sources
PubMed2002

Pterygium in Indonesia: prevalence, severity and risk factors.

AIM: To determine prevalence rates, severity, and risk factors for pterygium in adults in provincial Indonesia and to validate a clinical grading scheme in a population based setting. METHODS: A population based prevalence survey of 1210 adults aged 21 years and above was conducted in five rural villages and one provincial town in Riau province, Sumatra, Indonesia, an area near to the equator. A one stage household cluster sampling procedure was employed: 100 households were randomly selected from each village or town. Pterygia were graded for severity (T1 to T3, by visibility of episcleral vessels) and the basal and apical extent measured by an ophthalmologist (GG) with a hand held slit lamp. Refraction was measured by hand held autorefractor (Retinomax). Face to face household interviews assessed outdoor activity, occupation, and smoking. The participation rate was 96.7%. RESULTS: The mean age was 36.6 years (SD 13.1), 612 were male. The age adjusted prevalence rate of any pterygium was 10.0% (95% confidence intervals (CI) 8.2 to 11.7) and of bilateral pterygia was 4.1% (95% CI 2.9 to 5.3). There was a significant dose-response relation with age (2.9% (95% CI 0.4 to 5.8) for 21-29 years versus 17.3% (95% CI 10.4 to 24.2) 50 years and above; p for trend <0.001) and occupations with more time outdoors (p for trend = 0.02). This was true for both sexes, all grades of lesion (T1 to T3), and bilateral disease. A multivariate logistic regression model showed pterygium was independently related to increasing age and outdoor activity 10 years earlier. The mean basal diameter = 3.3 mm (SD 1.51, range 0.1-9.5) and extent from limbus = 1.4 mm (SD 1.18, range 0.1-8.0). Higher grade pterygia were larger for basal and apical extent (p for trend <0.001). The presence of pterygium was associated with astigmatism (defined as cylinder at least -0.5 dioptres (D); p <0.001). This association increased with increasing grade of lesion (p for trend <0.001). Median cylinder for those with pterygium (-0.50 D) was greater than for those without (-0.25D), (p <0.001), and increased with higher grade of lesion (p for trend <0.001). For eyes with pterygia, magnitude of astigmatism was associated with greatest extent from the limbus, (p = 0.03), but not basal width (p = 0.99). CONCLUSIONS: There is a high prevalence rate of pterygia in provincial Sumatra. The independent increase with age and past outdoor activity (a surrogate for sun exposure) is consistent with previous findings. Clinical grading of pterygium morphology by the opacity of the lesion was a useful additional marker of severity.

Adult↗
PubMed2002

Prevalence and risk factors associated with dry eye symptoms: a population based study in Indonesia.

AIM: To determine the prevalence and identify associated risk factors for dry eye syndrome in a population in Sumatra, Indonesia. METHODS: A one stage cluster sampling procedure was conducted to randomly select 100 households in each of the five rural villages and one provincial town of the Riau province, Indonesia, from April to June 2001. Interviewers collected demographic, lifestyle, and medical data from 1058 participants aged 21 years or over. Symptoms of dry eye were assessed using a six item validated questionnaire. Presence of one or more of the six dry eye symptoms often or all the time was analysed. Presence of pterygium was documented. RESULTS: Prevalence of one or more of the six dry eye symptoms often or all the time adjusted for age was 27.5% (95% confidence interval (CI) 24.8 to 30.2). After adjusting for all significant variables, independent risk factors for dry eye were pterygium (p<0.001, multivariate odds ratio (OR) 1.8; 95% CI 1.4 to 2.5) and a history of current cigarette smoking (p=0.05, multivariate OR 1.5; 95% CI 1.0 to 2.2). CONCLUSIONS: This population based study provides prevalence rates of dry eye symptoms in a tropical developing nation. From our findings, pterygium is a possible independent risk factor for dry eye symptoms.

Adult↗
PubMed2002

Self perceived work related stress and the relation with salivary IgA and lysozyme among emergency department nurses.

AIMS: To assess and compare the self perceived work related stress among emergency department (ED) and general ward (GW) nurses, and to investigate its relation with salivary IgA and lysozyme. METHODS: One hundred and thirty two of 208 (63.5%) registered female ED and GW nurses participated in the study. A modified mental health professional stress scale (PSS) was used to measure self perceived stress. ELISA methods were used to determine the salivary IgA and lysozyme levels. RESULTS: On PSS, ED nurses had higher scores (mean 1.51) than GW nurses (1.30). The scores of PSS subscales such as organisational structure and processes (OS), lack of resources (RES), and conflict with other professionals (COF) were higher in ED than in GW nurses. ED nurses had lower secretion rates of IgA (geometric mean (GM) 49.1 micro g/min) and lysozyme (GM 20.0 micro g/min) than GW nurses (68.2 micro g/min, 30.5 micro g/min). Significant correlations were observed between PSS and log IgA and lysozyme secretion rates. OS, RES, and COF were correlated with log IgA and lysozyme levels. CONCLUSION: ED nurses, who reported a higher level of professional stress, showed significantly lower secretion rates of salivary IgA and lysozyme compared to GW nurses. Salivary IgA and lysozyme were inversely correlated with self perceived work related stress. As these salivary biomarkers are reflective of the mucosal immunity, results support the inverse relation between stress and mucosal immunity.

Adult↗
PubMed2002

Effluents from a pulp and paper mill: a skin and health survey of children living in upstream and downstream villages.

OBJECTIVES: A health survey of three villages (upstream village Rantau Baru and two downstream villages, Sering and Pelalawan) in the vicinity of a pulp and paper mill along the Kampar river in the province of Riau, Indonesia was conducted to find whether exposure to the effluents from the mill was related to skin conditions and ill health. METHODS: A cross sectional survey was carried out of children living in the three villages. RESULTS: Common skin conditions such as dermatitis, fungal infections, insect bites, and miliaria were found. No significantly increased risk of dermatitis or any illness in general was found with increasing levels of exposure to river water for downstream villages when compared with the upstream village. However, there was an increased risk of diarrhoea in Sering especially with drinking water directly from the river (prevalence rate ratio (PRR) 4.9, 95% confidence interval (95% CI) 0.4 to 63.9). An increased risk was also found within the upstream village Rantau Baru (PRR 2.3, 95% CI 0.9 to 5.8) and downstream village Sering (PRR 1.4, 95% CI 0.4 to 5.2) when children who drank water directly from the river were compared with those who never did. Analysis of the river water also showed physical and chemical variables within the acceptable range except for faecal coliforms (6 MPN/100 ml) found in the sample taken from Sering. CONCLUSIONS: The effluent from the mill is unlikely to be causing skin conditions and ill health. Diarrhoea may be due to faecal coliform contamination of the water because all raw sewerage is deposited in the river. Community health outreach programmes are being implemented based on these findings.

Child↗
PubMed2001

Occupational health in general practice in an industrial area of Singapore.

The aim of this study was to estimate the caseload with regard to the proportion of work-related medical cases in factory workers and to survey knowledge of and attitudes to occupational medicine among doctors in an industrial area in Singapore. To this end, a self-administered questionnaire was given to 74 general practitioners in the industrial district of Jurong in Singapore. Overall, there was an 89.2% response rate. Thirty-three of the 66 respondents were males. Mean age was 40.8 years (range 27-64 years). Twenty-four (36%) had some postgraduate training in occupational medicine (GP-OM) while the rest did not (GP). The caseload for all doctors was similar with regard to the number of adult patients and, more specifically, the number of factory workers seen per day. The majority of doctors (76.6%) felt that <10% of factory workers seen had work-related problems. Most (70%) felt confident in dealing with the occupational problems that arose. However, a large percentage (78% of GPs, 45.8% of GP-OMs) felt that training in occupational medicine was inadequate. This is reflected in the knowledge questions, where GPs did not score as well as GP-OMs. It was concluded that GPs working in this industrial area see a good proportion of factory workers, in a fair number of cases for work-related problems. However, only a third of the GPs are qualified in occupational medicine. These factors highlight the need for more emphasis on occupational medicine training among general practitioners, especially those working in industrial areas.

Adult↗
PubMed2001

Salivary cortisol levels and work-related stress among emergency department nurses.

The objective of this study was to assess and compare the self-perceived work-related stress of emergency department (ED) and general ward (GW) nurses and to assess the relationship between self-perceived stress and salivary cortisol levels in these groups of nurses. Seventy-three female ED (n = 23) and GW (n = 50) nurses from a general hospital completed a self-administered questionnaire. A modified mental health professional stress scale (PSS) was used to measure self-perceived work-related stress. Salivary samples were collected at the start and end of morning shiftwork. An enzyme-linked immunosorbent assay method was used to determine the salivary cortisol concentration (nmol/L). ED nurses perceived that nursing was more stressful (mean, 1.58; 95% confidence interval [CI], 1.35 to 1.81) than did GW nurses (mean, 1.30; 95% CI, 1.18 to 1.40). On the PSS subscales, scores of organizational structure and process, lack of resources, and conflict with other professionals were higher in ED nurses (all P < 0.01). The morning cortisol was significantly lower in ED (geometric mean, 9.10; 95% CI, 6.62 to 12.42 nmol/L) than in GW (geometric mean, 15.45; 95% CI, 11.86 to 20.14 nmol/L) nurses. Log morning salivary cortisol was negatively correlated with PSS (r = -0.255), scores of organizational structure and process, and conflict with other professionals (all P < 0.05). The difference between morning and afternoon cortisol concentration in ED nurses (geometric mean, 6.35; 95% CI 4.14 to 9.93 nmol/L) was lower than in GW nurses (geometric mean, 12.42; 95% CI, 9.38 to 16.28 nmol/L). The log value of the difference correlated marginally with PSS (r = -0.21, P = 0.07) and significantly with scores of organizational structure and process, lack of resources, and conflict with other professionals (all P < 0.05). There was no difference between the two groups in afternoon salivary cortisol level. ED nurses perceived more stress compared with GW nurses. Morning salivary cortisol concentration is better correlated with PSS compared with the morning-afternoon salivary cortisol difference. The result raises the possibility of using a single morning salivary cortisol sample to reflect self-perceived stress.

Adult↗
PubMed2001

Differential expression of Hox A5 in human colon cancer cell differentiation: a quantitative study using real-time RT-PCR.

Fifteen different homeobox genes were identified from normal colon mucosa, untreated COLO 205 and herbimycin A treated COLO 205 cells in a degenerate primer RT-PCR screen. Several of the homeobox genes, including Cdx-1, Cdx-2, Pdx-1 and Hox A5, showed a trend toward differential expression in normal colon mucosa, and undifferentiated COLO 205 cells. Hox A5 was recently shown to suppress growth and induce p53-dependent apoptosis. To determine if Hox A5 was differentially expressed in differentiation of colon epithelial cells, we quantified Hox A5 expression by real-time quantitative RT-PCR. Expression of Hox A5 was 5.3- and 4.8-fold higher in normal colon mucosa compared to COLO 205 and HT-29 cells, respectively, suggesting that Hox A5 expression was higher in differentiated compared to undifferentiated colon epithelial cells. To avoid the complexity of tissue specimens and the influence of individual variation in Hox A5 expression, the effect of differentiation on Hox A5 expression was studied in COLO 205 cells treated with herbimycin A. The quantitative study showed that Hox A5 expression was increased when COLO 205 cells were induced to differentiate. The expression of Hox A5 was about 2-fold higher in the cells treated for 48 h compared to the untreated poorly-differentiated cells. The present study shows that Hox A5 may be involved in intestinal cell differentiation, in addition to its role in apoptosis.

Benzoquinones↗
PubMed2000

A South-East Asian perspective.

In order to discuss the subject of occupational medicine in the next century, changes in the present demographic profile and work activity must be considered first. Only then can the challenges be identified, and appropriate strategies be formulated to respond to them. In the diverse countries of South-East Asia, improved health and work conditions, the advent of new technology, a redistribution of work activity, and an ageing workforce can be expected. Two other factors that have specific impact in the region are the recent financial crisis and the occurrence of an international environmental haze from forest fires. The various countries in South-East Asia, which are in different stages of development, and have different problems and priorities, will respond differently to the demands for occupational health. It is likely that there will be a shift in the focus of current health care activities towards specific work sectors, the recognition of new hazards at work, the identification of newly emerging work related diseases, and an increase in health promotion in the workplace. Hopefully, there will be improved training of health professionals to ensure that there are adequate numbers and that they are well prepared to face these changes. Responsive, appropriate and well enforced labour legislation to protect the health of all workers, and international cooperation in occupational and environmental health are also required. As global and regional economic conditions continue to remain unstable and the impact of the crisis further takes its course, the final effect on occupational health in South-East Asia remains to be seen.

Asia, Southeastern↗
PubMed2000

Ageing and fitness to work.

Ageing workers can be found in almost all occupations. Assessment of fitness to work in these workers is important, as it aims to match their functional capacity (which is reduced compared to younger workers), to the demands of their work (which may remain the same as that for younger workers). This outcome of assessment is influenced by the interaction between functional capacity, state of health, the nature of work, and possibilities for work accommodation. The assessment of functional capacity should include physical, mental and social capacity, as well as assessment of any disability. In addition to clinical or laboratory measurements, several authors have suggested the use of a 'work ability index' for specific occupations as a practical means of selecting the appropriate worker for the job. This index can also be used for monitoring functional capacity. In addition, as for any fitness to work assessment, a good understanding of the nature of the work and the work environment is required, and possibilities for work accommodations considered. While changes in the work environment and working conditions can be made to suit the functional capacity of the ageing worker, the maintenance of functional capacity is another important issue. There is a place for a greater role for disease screening and health promotion for such workers.

Aged↗
PubMed2000

Factors associated with condom use for oral sex among female brothel-based sex workers in Singapore.

BACKGROUND AND OBJECTIVE: The prevalence of oral sex increased from 27.1% in 1992 to 81.1% in 1997, with a concomitant increase in pharyngeal gonorrhea, among female sex workers in Singapore. The extent of condom use for oral sex among them is unknown. GOAL: To determine the prevalence of and factors associated with consistent condom use during oral sex. STUDY DESIGN: A cross-sectional study of 225 women randomly selected from the surveillance scheme register of female brothel-based sex workers with a history of oral sex documented in their medical records. RESULTS: Slightly more than half (56.9%) consistently used condoms for oral sex compared to 97% for vaginal sex. Condom use was significantly higher among middle than high class sex workers (adjusted rate ratio: 1.52, 95% CI: 1.01-2.29) and those with negotiation skills (adjusted rate ratio: 1.95, 95% CI: 1.32-2.07). CONCLUSION: Sex workers should be taught skills to negotiate condom use for oral sex.

Adult↗
PubMed2000

A prospective study on condom slippage and breakage among female brothel-based sex workers in Singapore.

BACKGROUND: Concerns about the effectiveness of condoms in preventing sexually transmitted diseases have been raised. Data are lacking on condom failure and its associated factors among sex workers in Southeast Asia. GOAL: To assess factors associated with condom breakage and slippage. STUDY DESIGN: A prospective study on condom breakage and slippage over a 1-day period was conducted among 219 female brothel-based sex workers in Singapore in 1997. RESULTS: Condom breakage and slippage rates among 1,885 episodes of condom use were 1.2% (95% CI, 0.7-1.8) and 2.1% (95% CI, 1.2-3.0), respectively. After adjusting for intracluster effects and confounders, condom breakage and slippage were significantly associated with duration of sex work and spontaneity of clients to use condoms. CONCLUSION: Condom use among sex workers should be promoted in view of the low failure rates. Strategies to reduce condom breakage and slippage should be directed at sex workers with increased risk of condom failure.

Adult↗
PubMed2000

The prevalence and pattern of contact lens use in a Singapore community.

PURPOSE: We conducted a cross-sectional survey to determine the prevalence, socio-demographic patterns, and characteristics of contact lens use in an electoral community in Singapore. METHODS: One thousand eight hundred fifteen persons aged between 12-55 years from 768 households were surveyed using a standardized pre-tested questionnaire. RESULTS: The percentage of contact lens wearers in the survey populations was 9.0%. Forty-two percent of surveyed individuals were myopes, 21.8% of whom wore contact lenses. Contact lens wearers tended to be young Chinese females with higher level education and incomes. Most wore monthly disposable or daily wear soft contact lenses. Convenience and cosmesis were the main reasons cited for contact lens wear. Optometrists, who prescribed the bulk of contact lenses, were also the most influential in determining consumers' choice of lenses. CONCLUSION: Information gathered in this population-based survey may be used to facilitate national eye-care planning and provide a baseline for comparison with rates of lens wear found in other countries and in future surveys.

Adolescent↗
PubMed2000

A community study of male androgenetic alopecia in Bishan, Singapore.

BACKGROUND: Androgenetic alopecia is the most common form of hair loss. It affects a large number of the local male population, with 1,812 men seeking treatment for hair loss at the sole dermatological tertiary referral centre in Singapore in 1994. The aim of this study was to assess the prevalence of male androgenetic alopecia in the community. METHODS: A questionnaire-based cross-sectional survey with a one-stage sampling method was conducted. Each male was diagnosed clinically and the severity graded according to the Norwood Criteria. The survey area was in Bishan East, a housing estate with 8,004 households. A total of 335 households were selected for the survey. RESULTS: The household response rate was 84%. Within these households, 254 out of 378 men participated in the study (67% response rate). The prevalence of androgenetic alopecia was found to be 63%. The prevalence of the condition increased with age, from 32% among young adults aged 17 to 26 years to 100% among those in their 80s. Proportionately more Indians (87%) were affected compared to Chinese (61%). 81% of the respondents with androgenetic alopecia did not seek help as they did not view it as a problem. Of those seeking treatment, 74% used non-medical methods of unproven effectiveness. CONCLUSION: There is a high prevalence of androgenetic alopecia in the community in Singapore. Age specific prevalence and racial differences correlate well with both Western and local studies respectively.

Adolescent↗
PubMed1999

Phytophotodermatitis due to the application of citrus hystrix as a folk remedy.

We report a case of extensive phytophotodermatitis in a hiker. This was caused by the application of the juice of a member of the Rutaceae family, Citrus hystrix, as a folk remedy to ward off biting insects. Besides the Rutaceae, plants belonging to the families Umbelliferae, Moraceae and Leguminosae also contain psoralens and can cause phytophotodermatitis. In temperate countries, cases are often seen among children playing outdoors during summer, when psoralens are most abundant in wild and garden plants.

Citrus↗
PubMed1999

Are salivary immunoglobulin A and lysozyme biomarkers of stress among nurses?

Salivary immunoglobulin A (IgA) and lysozyme have been studied as possible biomarkers of stress. This study examined the stress levels among female nurses in various units and the relationship between these stress levels and salivary IgA and lysozyme secretion. One hundred ninety-five (43%) of 457 eligible female nurses from surgical wards/operating theaters (SURG), medical wards (MED), and outpatient clinics/day-surgery theaters (OPD) completed a self-administered questionnaire. From this group of 195 nurses, 124 provided a salivary sample accumulated over 5 minutes. Stress levels were assessed with a ten-point Stress Assessment Score (SAS) for Asians and a direct question on perceived life stress. Enzyme-linked immunosorbent assay and lyso-plate methods were used to determine salivary IgA and lysozyme levels. Forty-five percent of SURG, 35% of MED, and 17% of OPD nurses scored at least four points on the SAS. SURG nurses had the lowest IgA secretion (geometric mean; 95% confidence interval [CI]) rates (43 micrograms/min; 36 to 51 micrograms/min). The other groups had significantly higher salivary IgA secretion rates: MED (96 micrograms/min; 80 to 116 micrograms/min) and OPD (77 micrograms/min; 60 to 98 micrograms/min) Findings for salivary lysozyme (microgram/min) were similar; SURG (9 micrograms/min; 6 to 13 micrograms/min) MED (19 micrograms/min; 12 to 28 micrograms/min) and OPD (16 micrograms/min; 9 to 28 micrograms/min). The salivary IgA (Spearman's r = -0.22, P = 0.01) but not the lysozyme (Spearman's r = -0.01, P = 0.9) secretion rate correlated negatively with SAS. Nurses working in various units under different conditions experienced dissimilar levels of stress. Salivary IgA, but not lysozyme, correlated inversely with self-reported levels of stress. It may thus be a potential biomarker in future studies on stress.

Adult↗