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Biomedical subjects

C C Tan

Publications and source records attributed to C C Tan.

At least 19 recordsLinked to original sources
PubMed2005

Epidemiology of pterygium on a tropical island in the Riau Archipelago.

OBJECTIVES: To describe the epidemiology of pterygium among residents of an island in Indonesia and to examine the roles of age and gender as determinants of bilaterality and severity of the disease. METHODS: Voluntary eye screening on Pulau Jaloh, Riau Archipelago, Indonesia. Gender difference was tested using the chi2 test. The difference in age between subjects with and without disease was tested using unpaired Student's t-test. Odds ratio (relative risk) for gender was calculated using logistic regression model with adjustment for age. RESULTS: Of the 550 inhabitants, 477 (86.7%) responded to the eye screening. The overall prevalence rate of pterygium was 17.0%. Out of 211, 48 male (22.7%) and 33 out of 266 female subjects (12.4%) had the disorder, with the gender difference being statistically significant. Adjusted for age, the risk of disease was 3.1-fold higher among the males. In all, 71.6% of subjects with pterygium had bilateral disease. Subjects with pterygium were significantly older, their mean age being 42.9 years compared to 18.7 years among those without disease. The prevalence rates in male subjects increased from age 20 to reach a plateau of 63.6% at age 35 and remained stable thereafter. In the female subjects, the rates also increased with age, albeit at a slower rate, from age 20 to reach a plateau of 46.7% at age 55 and remained stable thereafter. CONCLUSIONS: There is a high prevalence rate of pterygium among the study subjects, with the rates increasing rapidly with age.

Adolescent↗
PubMed2005

Hypertension, antihypertensive agents and outcomes following renal transplantation.

UNLABELLED: Hypertension is common following renal transplantation and adversely affects graft and patient survival. However, strategies for antihypertensive drug therapy and target blood pressure have not been clearly defined. AIM: To assess the influence of achieved blood pressure and antihypertension drug therapy on graft and patient survival with the aim of identifying targets and event rates for future intervention studies. METHODS: We undertook a longitudinal follow up study of 634 renal transplant patients. Patients were surveyed in December 1994 and followed up after 102 months. Blood pressure (BP) was determined from the mean of three clinic readings and antihypertensive drug therapy recorded. RESULTS: Complete follow up data were available for analysis on 622 patients (57.2% male; mean age: 45.2 +/- 13.0 yr. There were 158 (25.4%) deaths and 115 (18.5%) death-censored graft failures. Lower systolic and diastolic blood pressure were associated with better graft survival in the Kaplan-Meier analysis. Univariate analysis showed serum creatinine (HR 1.012, p < 0.001), duration of renal replacement therapy (HR 0.946, p = 0.012), age (HR 0.979, p = 0.014) and pulse pressure (HR 1.017, p = 0.044) to be predictors of graft survival with serum creatinine and duration of renal replacement therapy as the only significant factors in the multivariate analysis. Lower systolic and pulse pressure were associated with better patient survival in the Kaplan-Meier analysis. Age (HR) 1.062, p < 0.0001), serum creatinine (HR 1.002, p = 0.021), diabetes (HR 3.371, p < 0.0001), and pulse pressure (HR 1.013, p = 0.036) were significant predictors of patient survival in the univariate and multivariate analysis. Patient survival was reduced with increasing number of antihypertensives (p < 0.05), as was graft survival (p < 0.05). Reduced patient and graft survival were seen in patients prescribed calcium channel antagonists (p < 0.01). There was no increased patient mortality in those patients on beta-blockers or angiotensin converting enzyme (ACE) inhibitors. CONCLUSION: Hypertension is a risk factor, which remains despite the use of anti-hypertensives, for reduced patient and graft survival. The risk was not significant when blood pressure was entered together with serum creatinine in the multivariate analysis. Beta-blockers may have a beneficial effect on cardiovascular mortality, and ACE inhibitors a beneficial effect on both patient and graft survival. There is a pressing need for interventional studies to assess the impact of blood pressure targets on patient and graft survival and the effect of individual agents on these outcomes.

Adrenergic beta-Antagonists↗
PubMed2004

Mandatory temperature monitoring in schools during SARS.

During the SARS outbreak, temperature monitoring was mandatory for all Singapore schoolchildren. None of the Singapore children with SARS were detected through school temperature screening. However, temperature monitoring procedures have a powerful psychological effect of reassuring parents and the public that schools are safe during a SARS outbreak.

Adolescent↗
PubMed2004

Percutaneous dilational tracheostomy--a 3 year experience in a general hospital in Malaysia.

All percutaneous tracheostomies performed in the general intensive care unit (ICU), Hospital Sultanah Aminah, Johor Bahru, Malaysia, from July 1999 to June 2002 were studied. The tracheostomies were performed as an elective bedside technique in the ICU. A total of 352 percutaneous tracheostomies were performed. Eighty-eight percent of the tracheostomies were completed within 15 minutes. The most common complication was bleeding which occurred in 52 patients (14.7%). The rest of the complications encountered were:- transient hypoxia twelve (3.4%), inability/ difficulty to insert tracheostomy tube eight (2.3%), false passage four (1.1%), transient hypotension two (0.6%), pneumothorax two (0.6%), peristomal infection two (0.6%), subcutaneous emphysema one (0.3%), cuff rupture one (0.3%), oesophageal cannulation one (0.3%), and granuloma formation one (0.3%). Conversion to conventional tracheostomies were performed on 7 patients (2%). There was one unfortunate death related to percutaneous tracheostomy. In conclusion, percutaneous dilational tracheostomy can be used safely to manage the airway of critically ill patients.

Adolescent↗
PubMed2002

National disease management plans for key chronic non-communicable diseases in Singapore.

In Singapore, chronic, non-communicable diseases, namely coronary heart disease, stroke and cancer, account for more than 60% of all deaths and a high burden of disability and healthcare expenditure. The burden of these diseases is likely to rise with our rapidly ageing population and changing lifestyles, and will present profound challenges to our healthcare delivery and financing systems over the next 20 to 30 years. The containment and optimal management of these conditions require a strong emphasis on patient education and the development of integrated models of healthcare delivery in place of the present uncoordinated, compartmentalised way of delivering healthcare. To meet these challenges, the Ministry of Health's major thrusts are disease control measures which focus mainly on primary prevention; and disease management, which coordinates the national effort to reduce the incidence of these key diseases and their predisposing factors and to ameliorate their long-term impact by optimising control to reduce mortality, morbidity and complications, and improving functional status through rehabilitation. The key initiatives include restructuring of the public sector healthcare institutions into two clusters, each comprising a network of primary health care polyclinics, regional hospitals and tertiary institutions. The functional integration of these healthcare elements within each cluster under a common senior administrative and professional management, and the development of common clinical IT systems will greatly facilitate the implementation of disease management programmes. Secondly, the Ministry is establishing National Disease Registries in coronary heart disease, cancer, stroke, myopia and kidney failure, which will be valuable sources of clinical and outcomes data. Thirdly, in partnership with expert groups, national committees and professional agencies, the Ministry will produce clinical practice guidelines which will assist doctors and healthcare professionals to better manage important aspects of the key diseases. Finally, the Ministry has committed funds to support selected National Disease Management programmes, illustrated by the disease management plan for asthma.

Chronic Disease↗
PubMed2002

Prevention and control of non-communicable diseases in Singapore: a review of national health promotion programmes.

The epidemiological transition in Singapore from infectious to chronic, non-communicable diseases created different challenges for our public health system. The population-based strategy is adopted in primary prevention, through the promotion of a healthy lifestyle--smoking cessation, physical activity, eating right and managing stress. Complementing this are measures to detect chronic conditions early through screening and optimal treatment of the disease. While improvements were seen in the common risk factors of smoking and physical inactivity, prevalence of measurable risk factors like hypertension increased between 1992 and 1998. In 2000, the Ministry of Health initiated a series of national disease management plans for major disease conditions affecting Singaporeans. This approach uses a comprehensive and systematic approach to integrate the various components, with identification of responsible parties to ensure successful implementation of initiatives. Chronic diseases will remain prevalent as our society rapidly ages. Close monitoring of our initiatives in disease management will provide information on the long-term efficacy of such strategies.

Chronic Disease↗
PubMed2000

An audit of percutaneous endoscopic gastrostomy in a general hospital in Singapore.

OBJECTIVE: We conducted an audit on 50 percutaneous endoscopic gastrostomies (PEGs) performed by physician endoscopists from January 1996 up to November 1997. DESIGN: A retrospective cohort study was conducted. RESULTS: The mean age of the patients was 68.5 years (range 20-101) and the main indications were cerebrovascular accident in 40 (80%), neurological dysphagia in six (12%) and head injury in three (6%). The interval between the diagnosis of dysphagia and PEG was > 60 days in 19 patients (38%), 31-60 days in eight (16%) and < or = 30 days in 23 (46%). The commonest reason for PEG insertion was intolerance to nasogastric tube in 49 patients (98%). Twelve patients had antibiotics given concurrently for other infections and two had antibiotics given specifically to cover PEG insertion. There was evidence of post-PEG infection in two of 14 patients given antibiotics (14%) and in 14 of 36 patients not given antibiotics (39%). By Cox regression, the adjusted relative risk of infection in patients receiving antibiotics versus those not receiving was 0.6927 (95% CI 0.3396-1.4130; not significant). The 30-day mortality was 7/48 patients (15%), with two patients lost to follow-up before 30 days. There were no deaths directly attributable to PEG. CONCLUSIONS: PEG is still not adequately requested by doctors for patients needing enteral feeding for more than 30 days. The use of antibiotics in this retrospective cohort study failed to show any benefit in reducing the rate of infective complications.

Adult↗
PubMed2000

Pyogenic liver abscess--a tropical centre's experience in management with review of current literature.

AIM OF STUDY: To perform a retrospective study, with the help of literature review, of the management of patients with pyogenic liver abscess in a general hospital. METHOD: A retrospective study of 73 consecutive patients treated atTanTock Seng Hospital between January 1994 and December 1997 was conducted to determine the demographic, clinical, laboratory, radiological and microbiological characteristics of these patients, as well as the management strategies employed. RESULTS: Liver abscess was more common in males, occurring more frequently in the right hepatic lobe. Most patients presented with non-specific clinical and biochemical features. A raised alkaline phosphatase level was the most common biochemical abnormality found in about two-thirds of patients. Ultrasonography was not as sensitive as computed tomographic scans in detecting abscesses. Klebsiella pneumoniae was the most common etiological agent detected in cultures of blood and abscess aspirates. All patients were treated with intravenous antibiotics. Twenty-two (30%) needed percutaneous catheter drainage and five (7%) required surgical management. There was no hospital mortality in our series. Prolonged hospitalisation was associated with advanced age, degree of loculation within the abscess, concomitant diabetes mellitus and Klebsiella septicaemia. CONCLUSION: Pyogenic liver abscesses require a high index of suspicion for early diagnosis. When appropriate therapy in the form of antibiotics in combination with percutaenous drainage or surgery is administered, mortality is very low. However, significant morbidity is still a problem, particularly in the elderly, diabetic patient.

Adolescent↗
PubMed1999

Genotype/phenotype correlations in X-linked dominant Charcot-Marie-Tooth disease.

We have studied the relationship between genotype, clinical phenotype, and pathology in 13 families with dominant X-linked Charcot-Marie-Tooth (CMT) neuropathy. Connexin32 (Cx32) gene mutations were spread throughout the coding region and included eight missense mutations, one 8-bp deletion/4-bp insertion frame shifting mutation, two nonsense mutations, and one deletion of the entire coding sequence. One hundred sixteen affected CMTX patients (53 males and 63 females) and 63 unaffected, at-risk individuals were compared by neurological and electrophysiological examinations and analyzed by gender; nerve biopsies were available from seven index cases. It was found that mutations within all regions of the Cx32 gene coding sequence caused an identical clinical phenotype. Male CMTX patients were affected more severely and showed an age-dependent progression of clinical signs and of the pathology; there was, however, variability in the severity of disease expression, irrespective of age, among males within families of defined genotype. All but 10% of female CMTX patients had only mild signs. Motor nerve conduction velocities were moderately slowed (median nerve MNCV: males 34.5 +/- 6.2 m/sec; females 45.8 +/- 7.3 m/sec), and motor and sensory nerve amplitudes were reduced (median nerve CMAP: males 3.7 +/- 3.7 mV; females 7.8 +/- 3.4 mV), with electromyographic evidence of chronic denervation. Differences were significant between gender and between affected and unaffected individuals. In agreement with the electrophysiological observations, pathological studies showed evidence of paranodal demyelination and of a length-related axonal degeneration in motor and sensory nerve fibers. Correlations between genotype and clinical phenotype suggested that missense mutations located within the second transmembrane domain and/or cytoplasmic loop might be associated with milder clinical phenotype, and therefore might be less disruptive of connexin32 gap junction function. Missense, chain-terminating, or deletion mutations in all other locations of the connexin32 protein caused severe forms of CMTX and disease onset in the first decade. Observed variability of disease severity among males within kinships suggests the influence of other modifying factors.

Charcot-Marie-Tooth Disease↗
PubMed1999

Peptic ulcer and gastritis in uraemia, with particular reference to the effect of Helicobacter pylori infection.

AIMS: To determine: (i) the prevalence of histological gastritis and peptic ulcer; and (ii) the clinical features of peptic ulcer, in patients with end-stage renal failure. METHODS: Upper endoscopy was performed by a single observer in 268 patients with end-stage renal failure over a 6-year period. Gastric histology and Helicobacter pylori status were studied in 40 consecutive subjects in whom there were no contraindications for gastric biopsy and who had not used antibacterial drugs in the preceding 4 weeks. As there are only limited data for healthy volunteers in Singapore, 33 age-, sex- and race-matched patients with functional dyspepsia from an earlier drug trial and 18 healthy volunteers who were not age-matched were used as controls. The clinical features of 43 consecutive uraemic patients with peptic ulcer were compared with those of 118 consecutive non-uraemic peptic ulcer patients seen by the same author. RESULTS: Among uraemic patients, histological gastritis was less common, compared with healthy volunteers and functional dyspepsia patients. Helicobacter pylori infection as assessed by histology was also less common among uraemic patients compared with functional dyspepsia patients, but the difference was not statistically significant on serological assessment. Uraemic patients with ulcer had an equal sex ratio, in contrast to a male preponderance among peptic ulcer patients with normal renal function. Uraemic patients with ulcer were more likely to be pain-free, to present with haemorrhage, to have multiple ulcers and postbulbar duodenal ulcers, but were less likely to have H. pylori infection. Among uraemic subjects, the prevalence of H. pylori infection was similar whether or not peptic ulcer was present. CONCLUSIONS: The prevalence of histological gastritis was lower in uraemic patients when compared with patients with functional dyspepsia and healthy volunteers. Peptic ulcers in uraemic subjects have different clinical characteristics from peptic ulcer in non-uraemic subjects.

Adolescent↗
PubMed1999

Weils' syndrome and concomitant hepatitis B infection.

Leptospirosis is a ubiquitous, spirochetal zoonosis which presents with a broad clinical spectrum. Weil's syndrome, characterised by jaundice, renal failure and bleeding manifestations is the most severe form. A high index of suspicion for the diagnosis is required to institute therapy promptly. We describe a case of serologically confirmed Weil's syndrome with concomitant hepatitis B infection.

Adult↗
PubMed1999

Cost effectiveness evaluation of the Ministry of Health Malaysia dialysis programme.

We determine the cost effectiveness of centre and home haemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD) and intermittent peritoneal dialysis (IPD) treatment in the Ministry of Health (MOH) programme. The viewpoint taken for this evaluation is that of MOH. Cost categories identified were capital cost, dialysis operational cost, medical cost and general hospital cost. Cost estimates were mostly based on actual resource utilisation. Life years saved were estimated based on Dialysis Registry data on 2480 HD and 732 CAPD patients. Overall, the cost-effectiveness ratio (CER) of centre HD was RM21620/life year saved. Those of home HD, CAPD and IPD were RM23375, RM30469 and RM36016 respectively. Sensitivity analyses did not change the ranking of the CER. We conclude the MOH dialysis programme was cost-effective, and among the various dialysis modalities centre HD was the most cost-effective.

Adult↗
PubMed1999

Outcome assessment of the Ministry of Health Malaysia dialysis programme.

We describe the outcomes on haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) provided by the Ministry of Health (MOH). The assessment was based on data from the Malaysian Dialysis Registry on 2480 HD and 732 CAPD patients who commenced dialysis between 1980 and 1996. Young patients (age < 40) have remarkable long term survival (life expectancies of 16 years on HD, 18 years on CAPD). Adjusting for background mortality, relative survival of older patients was as good as younger ones. Diabetics did poorly. 52% of HD and 26% of CAPD patients were employed in 1996. 71% of HD patients scored 10(normal) on QL index (a measure of quality of life) while 60% of CAPD patients have similar score. Differences in rehabilitation and QL index scores by age, gender and diabetes were also observed. Outcomes of dialysis in the MOH programme are reassuring.

Adult↗
PubMed1998

Genetic relationship of populations in China.

Despite the fact that the continuity of morphology of fossil specimens of modern humans found in China has repeatedly challenged the Out-of-Africa hypothesis, Chinese populations are underrepresented in genetic studies. Genetic profiles of 28 populations sampled in China supported the distinction between southern and northern populations, while the latter are biphyletic. Linguistic boundaries are often transgressed across language families studied, reflecting substantial gene flow between populations. Nevertheless, genetic evidence does not support an independent origin of Homo sapiens in China. The phylogeny also suggested that it is more likely that ancestors of the populations currently residing in East Asia entered from Southeast Asia.

Animals↗
PubMed1998

Laser therapy combined with brachytherapy for the palliation of malignant dysphagia.

BACKGROUND/AIM OF STUDY: Laser therapy is effective in relieving malignant dysphagia, but repeated treatments at 4 to 6 week intervals are usually required. This prospective randomised trial is designed to determine if addition of brachytherapy offers any advantages over laser therapy alone. METHODS: Patients with inoperable carcinoma of the oesophagus were randomised to receive either endoscopic Nd:YAG laser therapy alone, or laser followed by brachytherapy. Patients who developed worsening dysphagia during follow-up were offered further treatment as appropriate. RESULTS: Fourteen patients were randomised to receive laser only, and 12 to receive laser followed by brachytherapy. Of these 12, one was lost to follow-up and four did not receive brachytherapy because they were unfit, had extension into the cardia or had mainly extrinsic compression. These 4 are included on an 'intention-to-treat' basis. The mean therapeutic interval for the brachytherapy group was significantly longer, 83 days compared to 36 days for the laser group (p = 0.026). There were no differences in the degree of dysphagia relief, number of endoscopic procedures or survival times. CONCLUSION: The preliminary results of this trial suggest that brachytherapy in addition to laser therapy prolongs the first therapeutic interval. However, no long-term advantages have been shown.

Aged↗