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Biomedical subjects

T K Lin

Publications and source records attributed to T K Lin.

At least 55 records · Page 3Linked to original sources
PubMed1990

The pattern of diabetes in a primary health care setting in Singapore.

This is a study of Diabetes mellitus and its treatment in a single doctor government primary health care clinic in Singapore. Data was collected on the entire 349 patients with diabetes attending this clinic over a three month period in 1987. We found there was an increasing number of diabetics with age and a substantial proportion was above 70 years of age. Only 7% had their diabetes treated with diet alone and 9.6% were treated with insulin. Most (61%) patients were on tolbutamide, with 17.6% on glibenclamide and 5.9% on chlorpropamide. Hypertension was found in 38% of the diabetic patients but was not associated with increase in age of the patient. The duration of diabetes, but not the age of the patient, was positively associated with the number of drugs taken by the patient (chi-squared, p less than 0.05).

Adolescent↗
PubMed1989

Cysts of the pineal gland. A new clinical entity to be distinguished from tumors of the pineal region.

Thirty-two cases of pineal cyst diagnosed by magnetic resonance imaging (MRI) were reviewed and are described. The pineal cyst was demonstrated to be an area with slightly less intensity than the surrounding tissue and with slightly greater intensity than the CSF on T1-weighted images. On the T2-weighted images this lesion was identified as a high-intensity area with smooth margins and was homogeneous in nature. In three cases presenting with headache, compression of the vein of Galen was identified, and compression of the quadrigeminal plate was demonstrated in five cases. No patients presented with both pineal and quadrigeminal lesions. Of the cases, 63% were not detected by CT scanning alone. There were two cases in which the cyst ruptured and collapsed spontaneously during follow-up. It is emphasized that the presence of this lesion, which was more frequent than previously expected, should be kept in mind when diagnosing pineal tumors and should not be misdiagnosed. Surgery should not be undertaken unless the lesion produces symptoms due to the compression of the quadrigeminal plate, aqueduct, or the vein of Galen.

Adolescent↗
PubMed1978

Functional group contribution of bile salt molecules to partitioning of a quaternary ammonium N,N-dimethyl derivative of propranolol.

A quaternary ammonium N,N-dimethyl derivative of propranolol was extracted from pH 7.4 phosphate buffer into 1-octanol as ion-pairs with 12 different bile salts. The binding number, n, and the extraction constant, Ke, were determined. To obtain group contribution values of the bile salt molecule from the ion-pair extraction data, multiple linear regression analysis by the Free-Wilson technique was applied. The results showed that the fundamental premise of the functional group's contribution to the ion-pair extraction is valid. The functional groups of counterions contribute to the partitioning of the ammonium compound independently and additively in this system.

Bile Acids and Salts↗
PubMed1978

Pericardial angiosarcoma simulating pericardial effusion by echocardiography.

A fast-growing angiosarcoma caused incapacitation of a boy and death in a period of three months. The growth of the tumor was well documented by a series of echocardiograms. The heart was well encased by a thick layer of purplish vascular neoplasm enveloped mostly by thin pericardium, with some additional few foci of extracardiac metastasis. The heart weighed 2,000 gm. It is worthy to note that another cause of an echo-free space may be the presence of a pericardial tumor, rather than pericardial effusion.

Adolescent↗
PubMed1975

Linear relationships between plasma binding and lipophilicity of disopyramide derivatives.

The extent of plasma binding and the partition coefficient of disopyramide and 20 disopyramide derivatives were determined. Structural variations on the four functional groups around the tetrahedral carbon in the disopyramide molecule was found to influence both parameters to varying degrees. Three linear equations were developed to correlate the observed effects, depending on the type of chemical modification. The linear correlation between drug-plasma interaction and lipophilic character was analyzed theoretically. A simple model was derived to relate quantitatively the variation in the extent of plasma binding to the change in lipophilicity of disopyramide derivatives.

Arrhythmias, Cardiac↗
PubMed1975

Solution-solubility dependency of controlled release of drug from polymer matrix: mathematical analysis.

Two types of drug release mechanisms-matrix controlled (Q - t1/2 relationship) and partition controlled (Q - t relationship)-were reported previously. The dependency of the transition between these two processes on the solution solubility of drug is now analyzed. Mathematical expressions are derived to treat the systemic effects of the addition of varying volume fractions of the cosolvent system on the concentration gradients across both the drug depletion zone and hydrodynamic diffusion layer as well as on the partitioning behavior at the polymer-solution interface. The results are in excellent agreement with reported experimental observations.

Delayed-Action Preparations↗
PubMed1975

Binding of metronidazole and its derivatives to plasma proteins: an assessment of drug binding phenomenon.

Metronidazole and four derivatives were studied in vitro to investigate the differences in the extent of their binding to plasma proteins. Modification at the terminal portion of the alkyl side chain resulted in wide differences in the extent of binding. Molecular orbital calculations were performed by the CNDO and MINDO/2 methods to estimate the frontier electron density on the hetero atom at the 3'-position of the alkyl side chain. A linear correlation between the protein binding parameter (loge P) and the frontier electron density (qr) was observed for the binding of this group of trichomonicidal drugs. NMR spectroscopy was used to demonstrate that the alkyl side chain participated in the binding of these compounds to plasma proteins.

Blood Proteins↗