Biomedical subjects

L K Liem

Publications and source records attributed to L K Liem.

3 recordsLinked to original sources

PubMed1995

The patch clamp technique.

The introduction of the patch clamp technique less than two decades ago revolutionized the study of cellular physiology by providing a high-resolution method of observing the function of individual ionic channels in a variety of normal and pathological cell types. By the use of variations of the basic recording methodology, cellular function and regulation can be studied at a molecular level by observing currents through individual ionic channels. At a cellular level, processes such as signaling, secretion, and synaptic transmission can be examined. In addition, by combining the information from high-resolution electrophysiological recordings obtained by the patch clamp method with modern molecular biological techniques, further insight can be gained into the gene expression and protein structure of ionic channels. Given the ubiquity and importance of ionic channels, it is not surprising that their study has led to a new understanding of the mechanisms of certain disease processes and has given insight into treatments for these diseases. This review gives an historical perspective of the development of the patch clamp technique and an overview of the methodologies currently in use. Examples are shown to illustrate typical uses of the patch clamp technique with emphasis on the variety of recording configurations available and the advantages and drawbacks of each method.

Animals↗

PubMed1994

Phenytoin protects against hypoxia-induced death of cultured hippocampal neurons.

The neuroprotective actions of the anticonvulsant phenytoin (diphenylhydantoin, PHT) were evaluated using 3 week old primary hippocampal cultures derived from 19 day embryonic rat. When added to the culture medium prior to a hypoxic insult, PHT increased neuronal viability two-fold. Doubling extracellular Mg2+ concentration was similarly neuroprotective. In contrast, PHT was unable to protect against hypoxia-induced death in one week old cultures, nor was PHT protective against N-methyl-D-aspartate (NMDA)-induced neurotoxicity in cultures of either age. These findings suggest that non-NMDA receptor mechanisms are important in hypoxia-induced neuronal death, and may have important implications for the treatment of stroke.

Animals↗

PubMed1994

Thoracic epidural abscess.

Twenty-one cases of thoracic spinal epidural abscess occurring over a 10-year period were retrospectively reviewed. Diagnosis was made by MRI or myelography and confirmed in the operative cases. A bacterial agent was isolated in 18 of the cases (86%). When measured, the erythrocyte sedimentation rate was elevated in all cases. Four patients who presented without neurologic deficits remained intact. All patients who presented with neurological deficits underwent surgical intervention in addition to intravenous antibiotics. Of the 15 patients who presented with a paraparesis of less than antigravity strength, five eventually were independent ambulators and continent. A good outcome resulted in 80% of those who underwent decompression within 24 h, as opposed to only 10% of the patients decompressed after 24 h. Good results can be obtained despite severe neurologic compromise when treated by rapid diagnosis and decompression of the spinal canal.

Abscess↗