Biomedical subjects

K C Tam

Publications and source records attributed to K C Tam.

23 records · Page 2Linked to original sources

PubMed1977

Three-dimensional imaging in the position camera using Fourier techniques.

A mathematical algorithm for three-dimensional reconstructions in the positron camera is described. Fouier techniques have been adapted for use in analysing the data from cameras with limited detector configuration. Noise instabilities from random fluctuations in the data are discussed and treated. The technique is tested on a computer-generated phantom and the results are presented. Ways of incorporating the effects of Compton scattering and detector response into the algorithm are discussed. It is concluded that the method is feasible and practical for obtaining accurate reconstructions.

Brain Neoplasms↗

PubMed1976

Acupuncture for several functional disorders. Part I.

This is Part I of a study whose purpose is two-fold, that is, to arrive at a classification of diseases under investigation according to their responsiveness to acupuncture therapy, and to discuss and identify the most effective loci for the diseases investigated. In Part I of this study, over 500 patients afflicted with hyperthyroidism, trigeminal neuralgia or intercostal neuralgia were treated with acupuncture therapy. The results of the treatment, together with the selection of acupuncture loci and the techniques of needle manipulation are reported in detail. Over 80% of the patients were found to have made excellent improvement. The three diseases are therefore classified as diseases on which acupuncture therapy yields excellent results.

Acupuncture Therapy↗

PubMed1975

The effect of acupuncture on essential hypertension.

Twenty-eight patients with essential hypertension were treated with acupuncture therapy. Sixteen showed excellent improvement in terms of the lowering of blood pressure to normal and the disappearance of original symptoms. Eight had moderate improvement and 4 showed no response. The results of treatment seem to indicate that improvement is closely related to the duration of disease and the history of drug treatment. The selection of acupuncture loci and the techniques of needle insertion and manipulation are discussed in detail.

Acupuncture Therapy↗

PubMedDate not supplied

Association behavior of biotinylated and non-biotinylated poly(ethylene oxide)-b-poly(2-(diethylamino)ethyl methacrylate).

Biotinylated and non-biotinylated copolymers of poly(ethylene oxide) (PEO) and poly(2-(diethylamino)ethyl methacrylate) (PDEAEMA) were synthesized by the atom transfer radical polymerization technique. The chemical compositions of the copolymers as determined by NMR are represented by PEO(113)PDEAEMA(70) and biotin-PEO(104)PDEAEMA(93), respectively. The aggregation behavior of these polymers in aqueous solutions at different pHs and ionic strengths was studied using a combination of potentiometric titration, dynamic light scattering, static light scattering, and transmission electron microscopy. Both PEO-b-PDEAEMA and biotin-PEO-b-PDEAEMA diblock copolymers form micelles at high pH with hydrodynamic radii (R(h)) of about 19 and 23 nm, respectively. At low pH, the copolymers are dispersed as unimers in solution with R(h) values of about 6-7 nm. However, at a physiological salt concentration (c(s)) of about 0.16 M NaCl and a pH of 7-8, the copolymers form large loosely packed Gaussian chains, which were not present at the low c(s) of 0.001 M NaCl. The critical micelle concentrations (cmc's) and the cytotoxicities of the copolymers were investigated to determine a suitable polymer concentration range for future biological applications. Both PEO-b-PDEAEMA and biotin-PEO-b-PDEAEMA diblock copolymers possess identical cmc values of about 0.0023 mg/g, while the cytotoxicity test indicated that the copolymers are not toxic up to 0.05 mg/g (>83% cell survival at this concentration).

Animals↗

PubMedDate not supplied

Polymeric nanostructures for drug delivery applications based on Pluronic copolymer systems.

The first part of this article reviewed the applications of nanostructures derived from Pluronic block copolymers that have potentials in the field of biomedical sciences. Pluronic block copolymers are used not only in drug delivery systems but also in gene and cancer therapies. In the second part, the chemical modifications of Pluronic copolymers and their applications in biomedical science were reviewed. Chemical modifications of Pluronic copolymers not only improve the properties of the polymers but they also impart more attractive properties to the block copolymers. The common systems used to modify Pluronic copolymers are polyacrylic acids, polybases, and biodegradable polyesters. Pluronics were also modified at both ends with functional groups to improve the mechanical properties of hydrogels.

Coated Materials, Biocompatible↗