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Biomedical subjects

T C Tan

Publications and source records attributed to T C Tan.

At least 37 records · Page 2Linked to original sources
PubMed1996

MR imaging of articular cartilage in the ankle: comparison of available imaging sequences and methods of measurement in cadavers.

OBJECTIVE: To assess hyaline cartilage of cadaveric ankles using different magnetic resonance (MR) imaging techniques and various methods of measurement. DESIGN AND PATIENTS: Cartilage thicknesses of the talus and tibia were measured in ten cadaveric ankles by naked eye and by digitized image analysis from MR images of fat-suppressed T1-weighted gradient recalled (FS-SPGR), sequences and pulsed transfer saturation sequences with (FS-STS) and without fat-suppression (STS); these measurements were compared with those derived from direct inspection of cadaveric sections. The accuracy and precision errors were evaluated statistically for each imaging technique as well as measuring method. Contrast-to-noise ratios of cartilage versus joint fluid and marrow were compared for each of the imaging sequences. RESULTS: Statistically, measurements from FS-SPGR images were associated with the smallest estimation error. Precision error of measurements derived from digitized image analysis was found to be smaller than that derived from naked eye measurements. Cartilage thickness measurements in images from STS and FS-STS sequences revealed larger errors in both accuracy and precision. Inter-observer variance was larger in naked eye assessment of the cartilage. Contrast-to-noise ratio of cartilage versus joint fluid and marrow was higher with FS-SPGR than with FS-STS or STS sequences. CONCLUSION: Of the sequences and measurement techniques studied, the FS-SPGR sequence combined with the use of digitized image analysis provides the most accurate method for the assessment of ankle hyaline cartilage.

Aged↗
PubMed1996

Measuring quality of life in different cultures: translation of the Functional Living Index for Cancer (FLIC) into Chinese and Malay in Singapore.

Quality-of-life assessment has become an accepted method of evaluation in clinical medicine. The technique is based on a patient's self-assessment of physical, psychological, and social function, as well as the effects of distressing physical symptoms. The most important aspect of quality-of-life assessment is that it brings into focus a patient-centred view of health outcome, which is broader than the physiologic measures which predominate in Western medicine. Strategies for the development and use of assessment questionnaires have evolved over the past 15 years, and numerous questionnaires have been created. Most originate in Western societies, with English as the most common language of development. Adapting such questionnaires for use in other language and cultural settings is an imprecise practice. Language translation and equivalent cultural meaning must both be addressed. This paper reports on the language translation process and results for the Functional Living Index for Cancer (FLIC) as translated into Chinese and Malay in Singapore. We employed a step-wise process beginning with translation/back translation, followed by structured pilot field trials and population sampling. Taped versions of the questionnaire were devised to meet illiteracy problems in the sample population. Paired comparisons of the Chinese and Malay versions of individual questions with their English counterparts show good correlations and similar means most of the time. Factor analysis on a population sample of 246 (112 Chinese, 35 Malay and 98 English speaking) with cancers of minimal, extensive or palliative extent is convergent with that obtained on a North American population. However, a separate analysis of the Chinese questionnaires showed some differences in factor pattern. Specific language and cultural translation difficulties are discussed. Of note is the predicted significant decrease in total FLIC scores with extent of disease within each of the language preference populations, which provides some evidence for the validity for each language version in the Singapore culture(s). Thus, the FLIC translations into Malay and Chinese in Singapore can be considered for use in local trials, subject to ongoing evaluation.

Activities of Daily Living↗
PubMed1995

An analysis of risk factors for the prediction of shoulder dystocia in 16,471 consecutive births.

This paper is a univariate analysis of the demographic, antepartum and intrapartum risk factors in a series of 16,471 consecutive deliveries in a tertiary obstetric and gynaecological unit in Singapore. In total, 12,229 term vaginal cephalic deliveries with 77 cases of shoulder dystocia were entered into the study for analysis. The incidence of shoulder dystocia was found to be 0.63% of all term vaginal cephalic deliveries. There is a direct relationship between increasing infant birthweight and incidence of shoulder dystocia. The critical birthweight for the prediction of shoulder dystocia is 3600 g. In order of decreasing relative risks, the factors which appear to be predictive of shoulder dystocia are a birthweight in excess of 3600 g, diabetes in pregnancy, lower social class, of Indian origin, maternal weight in excess of 70 kg, parity more than 4, and the use of oxytocics during labour. The local birthweight distribution is very different from the West. A policy for elective caesarean section for birthweights in excess of 4000 g (97% tile) would prevent 44% of shoulder dystocias, increase the caesarean section rate by 2% and half the perinatal mortality among births with shoulder dystocia.

Adult↗
PubMed1994

Effects of pre-conditioning and microbial composition on the sensing efficacy of a BOD biosensor.

Sensitivity and the linear range of BOD measurement of a microbial BOD sensor using a mixed cell population of Bacillus subtilis and Bacillus licheniformis 7B depend significantly on the proportion of the two microorganisms and on the cell population immobilized on the biofilm. Optimum characteristics were obtained with equal proportion of the two microorganisms and an immobilized cell population of not less than 10(8) in the biofilm. Pre-conditioning of newly installed biofilm was best carried out in high BOD solutions and the time required to fully activate the microbial system decreased with increasing cell population. Fully activated biofilm remained stable and gave reproducible results for over 200 measurements covering a time period of more than 2 months. The technique of cell immobilization used in the present study provided a close control of the population and composition of the two microorganisms in the biofilm. Consistent and reproducible quality biofilms can therefore be produced for the preparation of the microbial BOD sensor.

Bacillus↗
PubMed1994

Selectivity enhancement of an immobilized apple powder enzymatic sensor for dopamine.

An enzymatic dopamine sensor was prepared by covering the gas membrane of a dissolved oxygen probe with a polycarbonate membrane in which pretreated apple fines were immobilized, followed by another polycarbonate membrane precoated with a Nafion film on the outside. The cationic exchange property of the Nafion film and its preclusion of the anionic interferents from entering the biofilm resulted in significant enhancement of the sensor selectivity and the linear calibration range for dopamine. However, the additional diffusion resistance introduced by the Nafion film diminished the sensor response or sensitivity and increased the response and baseline recovery times for a given dopamine concentration. Nevertheless, the exclusion of the various interferents and the reduced concentration of the solutes in the biofilm reduced contamination and deactivation of the enzymes, resulting in better sensor stability, reproducibility and service life.

Biosensing Techniques↗
PubMed1994

Condom use negotiation among sex workers in Singapore: findings from qualitative research.

Following an earlier study of 806 sex workers in Singapore in which they were found to succeed only half the time in getting clients to use condoms, a qualitative investigation was conducted on 40 sex workers to explore their perceived barriers and approaches in negotiating condom use with clients. Five different patterns of condom use were identified: successful, unsuccessful, misinformed, passive and uninterested. The successful negotiators used several practical approaches to secure clients' compliance. Unsuccessful negotiators experienced problems such as inability to resist clients' pressure or respond to their queries. The misinformed group believed that regular clients were safe. The passive group did not negotiate condom use due to their perceptions of lack of support from peers and brothel keepers, and the uninterested group was apathetic with fatalistic perceptions of AIDS. The in-depth interviews with successful negotiators provided relevant, specific and practical information which could be disseminated to their peers to develop their negotiation skills. This qualitative study also provided useful insights on condom use negotiation and highlighted the need for comprehensive interventions which should not only aim at developing sex workers' negotiation skills but also at gathering support from brothel keepers to facilitate behaviour change, and public education directed at clients to increase condom use.

Adult↗
PubMed1994

The medical, social, and functional profile of Parkinson's disease patients.

The study looked at the medical, social, and functional aspects of 34 patients with idiopathic Parkinson's Disease (PD). Eighty-five percent were above 55 years and 35% were over 70 years. Twenty-four (71%) were males. Most patients had Stage II disease. Overall functional state of the patient correlated closely with the stage of Parkinson's disease. Patients were likely to be dependent if their disease severity was stage III or more. Eighteen (53%) patients would require a carer to be present at least part of the day and 3 (9%) patients would require a carer most of the time. Domestic chores such as meal preparation, housework, and shopping were also affected in most of those who were previously active in these tasks. Ten patients had given up work due to their Parkinson's disease. The lack of knowledge of the disease was shown both in the carers and the patients. Twenty-nine of the patients had no knowledge of the disease, and only one carer had superficial knowledge of the disease. The major social problems associated with the disease were loss of social contact, behavioural problems, family members under strain and communication problems within the family. Since Parkinson's Disease is a chronic illness, with associated disabilities, it is important that the physician should aim for a multidisciplinary approach. Patient and carer education should be given emphasis, and the many everyday functional problems addressed. Advice on life-style management and aids to overcome disabilities may help improve quality of life of the patient and reduce carer's stress.

Activities of Daily Living↗
PubMed1992

Sudden unexplained death syndrome. A review and update.

Sudden unexplained death syndrome (SUDS) among young healthy Thai construction workers in Singapore has been given much publicity recently. From May 1982 to July 1990, 226 SUDS were reported among them. In this article we review and compare studies on SUDS in the United States and South-east Asia. So far, studies to identify the causal factors have been inconclusive and they cannot explain the male preponderance and occurrence of death during sleep. Current hypotheses about the cause of SUDS have included stress, genetic factors, dietary deficiency (particularly thiamine), potassium deficiency, melioidosis and sleep disorders. The following areas are suggested for further research: epidemiological investigations on SUDS at its source; in-depth case studies of families with and without SUDS; role of dietary factors, biochemical studies with respect to thiamine, pyruvate and potassium metabolism in the victims and susceptibles; and histopathological studies of cases and controls.

Adolescent↗
PubMed1992

Sero-prevalence of hepatitis B infection among dental professionals.

Dental employees in government institutions in a State in Peninsular Malaysia were screened for exposure to hepatitis B virus (HBV) in 1989. Almost all (96.8%) of the 217 employees responded. One quarter (24.8%) was positive for at least one serological markers to HBV; 2.4% had hepatitis B surface antigen (HBsAg) and 22.4% had anti-body to HBsAg (anti-HBs). The presence of HBsAg was unrelated to age, sex, ethnicity, geographical locality and occupations of the subjects. The prevalence of anti-HBs increased with age and was highest for ethnic Chinese (53.6%), followed by Indians (25%), compared to Malays (14.9%) (p less than 0.001) and were increased among dentists (53.1%) and assistant nurses (33.3%). The overall prevalence of HBsAg and anti-HBs were similar to the situation in the community. However, dentists and their chairside assistant nurses, with a higher proportion of Chinese, had higher anti-HBs prevalences compared with that of the general population.

Adult↗
PubMed1991

Personality, disability and acne in college students.

The relationship between acne, personality and disability was examined in a sample of 101 junior college students in Singapore. The clinical severity of their acne was assessed using a Acne Severity Grading Scale. The disability as perceived by the individual, was evaluated using the Acne Disability Index. Our data showed that there was no difference in personality, assessed by Eysenck Personality Questionnaire, between students with mild acne (Grades 0 and 2) and those with severe acne (Grades 4, 6 and 8). Personality influences the individual's perception of disability. Students with acne who were concerned about their facial appearance were more emotional and less tough-minded than those who were not. Otherwise, there was little disability resulting from the disease.

Acne Vulgaris↗
PubMed1991

Using role-play to teach consultation skills--the Singapore experience.

Role-play by students has been adopted as a teaching method for learning consultational skills during a primary health care posting for fourth year medical students in the National University of Singapore. This article describes the construction of the framework used, and reports on its evaluation by both the students and their teachers. The overall response to the session by the students was positive. Suggestions were then solicited to make refinements to enhance its efficacy as a teaching tool.

Communication↗
PubMed1990

Birth-weight of newborns to Chinese women subsequent to a previous abortion.

The mean birth-weight of firstborns of women was significantly higher when there was a previous abortion. The increase was 73.5 and 119.4 g in newborns of women with an induced and a spontaneous abortion respectively. This trend of significant increased birth-weight among firstborns of women with either a previous induced or spontaneous abortion continued for male infants, in recent migrants, and in subjects aged 20-24 and 30-34 years. Stepwise logistic regression analyses showed that a history of an induced or a spontaneous abortion increased the birth-weight of the firstborns, while short maternal stature and female newborn were associated with decreased birth-weight. For low birth-weight, a previous abortion was not selected into the regression models but short maternal stature and female newborns continue to contribute to low birth-weight. Prematurity and mean gestation were found not to be associated with previous abortion using logistic regression analyses.

Abortion, Induced↗
PubMed1984

Mortality from nasopharyngeal carcinoma and occupation in men in Hong Kong from 1976-81.

A study of deaths from Nasopharyngeal Carcinoma (NPC) among males in Hong Kong from the years 1976 to 1981 was conducted. Variations in NPC mortality among different occupational groups were investigated. The average death rate from NPC among males was 14 per 100,000 in the past ten years which is among the highest in the world. Comparisons using age specific mortality rates and direct age standardized mortality rates between occupational groups revealed increasingly high mortality in agricultural and fishery occupations (p less than 0.01), and being lowest among administrative occupations (p less than 0.05). The ten highest proportional mortality ratios for occupations were calculated and showed significantly high ratios among fishermen, plumbers, welders and fitters. The paper reviewed and discussed the possible reasons for these findings.

Adolescent↗
PubMed1984

A study of work injuries in eight Asian countries.

This study is based on a survey conducted in Hong Kong, Indonesia, Korea, Malaysia, the Philippines, Singapore, Sri Lanka and Thailand on occupational injuries during the years 1975-1980. The number of work accidents have risen rapidly during this period in all of the 8 countries studied. In the case of Thailand, the total number of work injuries increased four fold from 1975-1978, whereas, in Singapore it has almost doubled in 6 years. The number of permanent disablement nearly trebled in Korea, and the Philippines for the year 1967-1980. The largest percentage of accidents are lost-time injuries in all of the 8 countries. Thailand had a three fold increase in lost-time injuries whilst in Hong Kong the figure doubled. Six out of the 8 countries indicated that the building construction industry had the largest number of fatal accidents, followed by the manufacturing industry.

Accidents, Occupational↗