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Biomedical subjects

H K Cho

Publications and source records attributed to H K Cho.

35 records · Page 2Linked to original sources
PubMed1982

Development of a multichannel electrochemical centrifugal analyzer.

A new instrument has been developed that is similar in design and concept to the GeMSAEC centrifugal analyzer (Oak Ridge National Laboratory) except that electrochemical detection is used rather than optical detection. The present version has eight channels, each with its own detector. Problems of speed control and sampling synchronization are greatly minimized from those of a multichannel centrifugal analyzer having a single detector system. All eight sample compartments and polarographic cells are contained in a single Teflon rotor, 7.7 cm in diameter. The working electrodes are planar carbon electrodes. The initial application of the analyzer is in kinetic methods involving the rates of enzyme-catalyzed reactions. The initial system chosen was the glucose oxidase system. When the rotor is spun, the solution moves into the sample cell and up against the planar working electrode. The reaction starts and current is measured as a function of time at a constant applied voltage. The current output from each polarographic circuit is connected to a separate channel of a multiplexed analog-to-digital converter. The analyzer is controlled by a dedicated microcomputer system, which sets the polarographic cell voltages, collects the current-time data, and calculates the results.

Autoanalysis↗
PubMedDate not supplied

Effect of chronic ethanol consumption on selenium status and utilization in rats.

Effects of chronic ingestion of 2 levels of alcohol on selenium (Se) utilization were determined in initially Se-depleted rats. Male weanling rats were fed ad lib a Se deficient (0.012 mg/kg) basal diet for 4 weeks and then were meal-fed low or marginally adequate Se in the form of high Se yeast for 4 weeks. During Se repletion, ethanol, which replaced medium-chain triglycerides in the diet, provided 10 or 20 percent of food energy. The basal diet provided 80% of food energy as well as adequate protein, vitamins and minerals. In rats given adequate Se moderate chronic ethanol consumption did not influence Se absorption or retention, but increasing ethanol level raised Se in liver and whole blood in a linear fashion and in kidney in a quadratic manner. In this rat model measures of Se status were reduced by low Se intake, not chronic moderate ethanol ingestion.

Alcoholism↗
PubMedDate not supplied

Height, an important factor in the latency of somatosensory evoked potentials.

In a study of the relationship between height and the somatosensory evoked potentials (SEPs) in 24 normal individuals, we found significant linear correlations between height and the latencies of major peaks along the pathway in the median, ulnar, and first, third, and fifth digital SEPs. Thus, we conclude that the measured latency should be compared with the expected latency according to the subject's height before it is interpreted as normal or abnormal.

Adolescent↗