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Biomedical subjects

K K Tan

Publications and source records attributed to K K Tan.

At least 109 records · Page 6Linked to original sources
PubMed1989

Co-administration of ciprofloxacin and cyclosporin: lack of evidence for a pharmacokinetic interaction.

Ciprofloxacin is widely reported to lower theophylline clearance in patients. Since cyclosporin and theophylline are metabolized by cytochrome P-450 enzymes in the human liver, we investigated whether ciprofloxacin could alter the pharmacokinetics of cyclosporin in healthy volunteers. There was no significant difference (P greater than 0.05) in the pharmacokinetic parameters estimated for cyclosporin without and during ciprofloxacin administration. The results of the present study suggest that ciprofloxacin is unlikely to affect the pharmacokinetics of cyclosporin to a clinically important extent at a dosage of 500 mg twice a day.

Adult↗
PubMed1989

Surface of the brain: three-dimensional MR images created with volume rendering.

Image processing and volume rendering have been applied to magnetic resonance (MR) images to produce three-dimensional views of the surface of the brain. Four healthy volunteers and 17 patients with a variety of disorders underwent MR imaging of the head, and these images were processed and subjected to volume rendering. The resulting three-dimensional views depict abnormalities of the brain surface, as well as important landmarks of normal brain surface anatomy such as precentral, postcentral, superior temporal, and inferior frontal gyri, which are difficult to identify on cross-sectional images.

Adult↗
PubMed1989

The brain: integrated three-dimensional display of MR and PET images.

Three patients with intractable epilepsy, two with brain tumors, and one with encephalitis were imaged with magnetic resonance (MR) and positron emission tomography (PET). MR data were used to construct a three-dimensional (3D) computer model of the brain surface depicting the precentral (movement), postcentral (sensation), left inferior frontal (speech), and left superior temporal (hearing) gyri. PET-derived measurements of average surface metabolism were encoded as colors and mapped onto the 3D model by means of a retrospective technique for registering the two scans. The integrated 3D model depicted the location of PET-detected metabolic abnormalities with respect to the gyral anatomy visualized with MR. In each case, the predicted relationships were confirmed intraoperatively by means of inspection of the brain and electroencephalography. Multimodality 3D displays are likely to be particularly valuable for interpreting PET studies of epileptic patients and others with normal MR anatomy.

Brain↗
PubMed1989

Significance of the tuberculin test in Singapore.

The standard tuberculin test used by all Singapore government hospitals and institutions is the intradermal Mantoux test using 1 TU of PPD RT23 with Tween 80, and read 72 hours later. There is almost 100% BCG coverage in Singapore children for many years, and therefore the tuberculin skin reaction must be interpreted with special consideration. Taking 8 mm and above as positive, six month old infants vaccinated at birth gave a positive rate of 42% and a mean reaction size of 5.89 mm. The reaction appeared to wane rapidly and among 6 year old school children the positive rate dropped to 12% and the mean size to 2.38 mm. By the age of 11 years, the children showed a positive rate of 36% and a mean size of 6.27 mm. A further increase is observed in 15 year old children, the positive rate being 88% and mean size 13.28 mm. Among tuberculosis contacts, the positive rate and mean size of the tuberculin reaction are generally higher, especially in the younger age groups. Tuberculosis patients above 15 years old were observed to be practically all positive reactors with a mean size of at least 16 mm.

Adolescent↗
PubMed1985

Intravascular bronchioloalveolar tumour. A 20-year survival.

An unusual case of intravascular bronchioloalveolar tumour in a 40-year-old Chinese woman is reported. The woman has survived 20 years after radiological abnormalities were first noted in her lungs. This slowly progressing endothelial lung tumour has only recently been recognized as a distinct pathological entity.

Adult↗
PubMed1976

Light-induced synchronous conidiation in the fungus Botrytis cinerea.

Botrytis cinerea Pers. ex Fr. in stationary liquid cultures conidiated asynchronously in darkness after 4 days' growth. Synchronous conidiation was induced by irradiating dark-grown cultures with near-ultraviolet light for 12 h. The number of conidia increased very rapidly 10 h after the end of the photo-induction period, and conidiation was completed by the 14th hour. Filter paper cultures of the fungus also showed synchronous conidiation upon irradiation with near-ultraviolet light, but the rapid increase in the number of conidia took place 2 h earlier, conidiation being completed by the 12th hour. Cultures irradiated with blue light, however, produced sterile mycelia and showed complete suppression of conidiation.

Cell Division↗