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Biomedical subjects

S Y Tan

Publications and source records attributed to S Y Tan.

At least 37 records · Page 2Linked to original sources

QF-PCR-based prenatal detection of aneuploidy in a southeast Asian population.

OBJECTIVES: We have investigated the efficacy of using quantitative fluorescent polymerase chain reaction (QF-PCR) for the prenatal recognition of aneuploidy in chromosomes 13, 18, 21, X and Y. A total of 1115 samples, from mainly southeast Asian patients, were analysed and compared in a blind trial to the results previously obtained cytogenetically. METHODS: A multiplex PCR involving 15 short tandem repeat (STR) sequences was used. The probability of two or more of these markers being informative was calculated, and this required the multiplex PCR to be modified. RESULTS: The QF-PCR and previous cytogenetic results concurred, except for two products of conception (POC). One of these may be a case of complete uniparental disomy that was not recognized cytogenetically. The other was tetraploid, and as such appeared normal using QF-PCR. A mosaic trisomy 18 was correctly identified. The population sample was of a mainly Chinese, ethnic origin, and the allele frequency, size and heterozygosity appeared more restricted than the population groups analysed hitherto. CONCLUSION: The QF-PCR methodology is an efficient cost-effective method of screening for major chromosome aneuploidy, and, for certain referral categories, could be used alone. It also appears to be applicable to patients of different ethnic origins.

Alleles↗

Evaluation of live renal donors with three-dimensional contrast-enhanced magnetic resonance angiography in comparison to catheter angiography.

BACKGROUND: Catheter angiography is traditionally used to determine renal arterial anatomy in live renal donors. Three-dimensional (3D) contrast-enhanced magnetic resonance imaging (MRA) has been suggested as a noninvasive replacement. We assessed the possibility of using MRA in live renal donors in Malaysia. METHODS: Twenty-six consecutive live renal donors were recruited from 2000 to 2002. All potential donors underwent evaluation of the renal arteries using both techniques. Angiographic findings from both modalities were subsequently compared with surgical findings at the time of donor nephrectomy. The total number and diameter of the arteries and the presence of early branching and renal abnormalities were noted. RESULTS: Both angiographic modalities were able to detect multiple renal arteries with catheter angiography having a sensitivity of 100% and MRA a sensitivity of 97%. MRA missed one 1-mm artery due to a low index of suspicion. Renal artery caliber measurements were not significantly different between the two methods. However, both techniques tended to overestimate the caliber of the renal arteries when compared with measurements taken at surgery. Early branching was found in two arteries at the time of surgery, but only one was detected by both techniques. Renal cysts seen on MR were not detected by catheter angiography. CONCLUSIONS: Our findings suggest that noninvasive MRA is a promising substitute for catheter angiography to evaluate the renal arteries of live donors.

Adult↗

Epidemiology and cause of severe acute respiratory syndrome (SARS) in Guangdong, People's Republic of China, in February, 2003.

BACKGROUND: An epidemic of severe acute respiratory syndrome (SARS) has been associated with an outbreak of atypical pneumonia originating in Guangdong Province, People's Republic of China. We aimed to identify the causative agent in the Guangdong outbreak and describe the emergence and spread of the disease within the province. METHODS: We analysed epidemiological information and collected serum and nasopharyngeal aspirates from patients with SARS in Guangdong in mid-February, 2003. We did virus isolation, serological tests, and molecular assays to identify the causative agent. FINDINGS: SARS had been circulating in other cities of Guangdong Province for about 2 months before causing a major outbreak in Guangzhou, the province's capital. A novel coronavirus, SARS coronavirus (CoV), was isolated from specimens from three patients with SARS. Viral antigens were also directly detected in nasopharyngeal aspirates from these patients. 48 of 55 (87%) patients had antibodies to SARS CoV in their convalescent sera. Genetic analysis showed that the SARS CoV isolates from Guangzhou shared the same origin with those in other countries, and had a phylogenetic pathway that matched the spread of SARS to the other parts of the world. INTERPRETATION: SARS CoV is the infectious agent responsible for the epidemic outbreak of SARS in Guangdong. The virus isolated from patients in Guangdong is the prototype of the SARS CoV in other regions and countries.

China↗

Duty to third parties: a new worry for doctors.

The Hawaii Supreme Court ruled on June 10, 2002, that physicians might be liable to non-patient third parties if they fail to warn their patients regarding a medication's adverse effect on driving. Conceivably, this liability may also extend to physicians who fail to inform their patients and/or the Department of Motor Vehicles of medical conditions that affect operating a vehicle safely. Physicians must be cognizant of every medication's impact on driving ability, inform their patients of these adverse effects, and should consider asking their patients to stop driving if the risks are substantial.

Automobile Driving↗