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Biomedical subjects

K Suwa

Publications and source records attributed to K Suwa.

At least 91 records · Page 5Linked to original sources
PubMed1988

Changes in ambulatory activity and dopamine turnover in streptozotocin-induced diabetic rats.

We have observed the acute effects of streptozotocin (STZ) on ambulatory activity by employing the automatic apparatus for continuous and direct measurement of drinking and ambulation. Ambulatory activity (counts) in the control periods was 298.2 +/- 20.1 in the dark, 35.6 +/- 9.4 in the light, and 343.9 +/- 24.1 over 24 h. After administration of STZ (60 mg/kg, ip), the ambulatory activity gradually decreased [at 3 days: 165.0 +/- 12.3 in the dark (P less than 0.001), 34.0 +/- 10.5 in the light (P = NS), and 199.0 +/- 10.5 over 24 h (P less than 0.001). For determination of statistical significance, values were compared with those at the same time in the control groups. We observed decreased ambulatory activity in STZ-induced diabetic rats during the dark, but not the light, cycle. Moreover, ambulatory activity in STZ-induced diabetic rats gradually decreased, while the blood glucose level rose. Ambulatory activity correlated inversely with blood glucose level (r = -0.76; P less than 0.05). We measured the ratio of dopamine (DA) to 3,4-dihydroxyphenylacetic acid (nanograms per g) in the striatum. The turnover rate of DA was significantly lower in the diabetic rats than in the control group [diabetic, 0.102 +/- 0.003; control, 0.112 +/- 0.001 (mean +/- SE); P less than 0.05]. A negative correlation between the 3,4-dihydroxyphenylacetic acid to DA ratio and blood glucose level was observed (r = -0.693; P less than 0.01). The present study suggests that there are metabolic abnormalities in the striatum dopaminergic neurons of STZ-induced diabetic rats associated with decreased ambulatory activity.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

A computer program for studying blood gases in respiratory care.

We developed a computer program in a style of a game to help study blood gases in respiratory care. The program generates five simulated patients from a pool of 11. The player selects one patient, then the program calculates the patient's condition according to initial condition and selected treatment. Condition of the simulated patient may improve or deteriorate accordingly. Every two hours, the program display the data, requests the diagnosis and asks addition/change of treatment. The program then judges if diagnosis is correct. This process is repeated up to 48 hours. Finally a score and comments are displayed according to the performance of the patient and of the player. Students and young physicians used the original disk 312 times and more than 30 copies are distributed throughout the country. It is useful by itself as a self-teaching tool, but even more useful when combined with verbal teaching by instructors.

Journal Article↗
PubMed1985

Open loop-gain of the CO2 ventilatory control system.

We devised a method of measuring the open-loop gain for CO2-ventilatory feedback control system. The procedure is to gradually increase then decrease the PICO2 while measuring PICO2 and PACO2. We theorized that the gain is delta PICO2/delta PACO2-1. We measured this gain in 11 young healthy subjects and found the value to be 3.24, quite different from what had been reported so far by a conventional method. The conventional method calculates the gain as the ratio of the slope of CO2-response curve(s) over that of metabolic hyperbola. Analysis revealed that the conventional method requires an accurate knowledge of s-value at the very operating point. The assumption that the CO2 response curve is linear down to the operating point is probably the source of error. The open-loop gain for CO2 ventilatory control is in the order of 3, from which we may extrapolate that the slope of CO2-response curve at the operating point is much flatter than the normal value of more than 21/min/mmHg.

Adult↗