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Biomedical subjects

Y Fukui

Publications and source records attributed to Y Fukui.

588 records · Page 33Linked to original sources
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A fuzzy approach to the rate control in an artificial cardiac pacemaker regulated by respiratory rate and temperature: a preliminary report.

Fuzzy theory was applied to the rate control of a cardiac pacemaker which uses two parameters, respiratory rate and temperature, as the parameters for rate regulation. Using 25 fuzzy reasoning rules derived from five mongrel dogs, the pacing rates in three animals were calculated and compared with the intrinsic heart rates. It is concluded that the fuzzy method is well suited for the rate determination of a multi-parameter rate-responsive cardiac pacemaker.

Algorithms↗
PubMedDate not supplied

[3 fatalities after communal use of methamphetamine].

Two young men and a 17-year-old girl gathered in order to take methamphetamine, the quantity of which remained unknown. After a short time one of the men died on the scene; the other man, who was alcoholized in addition to having taken methamphetamine, fell over a railing from a height of several metres and suffered severe injuries before dying. The girl, who left for home by taxi, collapsed and died in a hospital about 2 hours later. Methamphetamine was detected in the blood of all three people. The autopsy results and the toxicological findings are reported and discussed with reference to the literature data.

Adolescent↗
PubMedDate not supplied

Vitamin D metabolism in biliary atresia: intestinal absorptions of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3.

In children with biliary atresia, defective intestinal absorption of vitamin D and impaired hepatic uptake and 25-hydroxylation of vitamin D lead to a deficiency of vitamin D and rickets. We recently observed severe rickets in a 3-year-old boy with corrected biliary atresia resulting in jaundice, despite oral treatment with 1 alpha-hydroxyvitamin D3 (1 alpha-OHD3) or 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. He had low 25-hydroxyvitamin D (25-OHD) and high 1,25-(OH)2D serum levels. Intramuscular vitamin D2 administration produced radiological and biochemical evidence of recovery. Oral 1,25-(OH)2D3 (0.1 microgram/kg) and 25-OHD3 (10 micrograms/kg) tolerance tests were done to assess the ability to absorb vitamin D and the effectiveness of using these drugs orally. Eleven children with corrected biliary atresia, aged 9 months to 7 years, were studied. In oral 1,25-(OH)2D3 tolerance tests, the increments above the baseline serum levels of 1,25-(OH)2D were 140.7 +/- 27.4 pg/ml in nonjaundiced patients (n = 5). In jaundiced patients (n = 3), 1,25-(OH)2D3 absorption in two patients with high basal 1,25-(OH)2D values was lower than that of nonjaundiced patients; however, the absorption in the third patient with a low basal value was similar to that of nonjaundiced patients. In oral 25-OHD3 tolerance tests, the mean increase of serum 25-OHD was 48.9 +/- 30.6 ng/ml in nonjaundiced patients (n = 5) and 23.7 +/- 9.5 ng/ml in jaundiced patients (n = 4), the peak serum 25-OHD levels being reached 6-12 h after 25-OHD3 loading.(ABSTRACT TRUNCATED AT 250 WORDS)

Biliary Atresia↗
PubMedDate not supplied

Salsolinol in the urine of nonalcoholic individuals after long-term moderate drinking.

Urine samples were collected before breakfast from 94 normal volunteers (41 males and 53 females) aged 25-70 years. Salsolinol (SA) was analyzed by gas chromatography-mass spectrometry (GC/MS), and dopamine, norepinephrine and epinephrine were determined using high performance liquid chromatography (HPLC). SA levels were significantly higher in the urine of male moderate drinkers (MDs) than in male seldom or non drinkers (SNDs). In females, however, a significant difference of urinary SA levels was not observed between MDs and SNDs. There was a sex difference of urinary SA levels among SND subjects, i.e., females showed a higher SA than males. Urinary catecholamines were not significantly altered by long-term moderate alcohol drinking in either sex. There was no correlation between urinary levels of dopamine and SA. These results indicate that urinary SA can be increased by long-term drinking even in normal, not alcoholic subjects.

Acetaldehyde↗
PubMedDate not supplied

Flow visualization evaluation of secondary flow in a centrifugal blood pump.

To design a less hemolytic and more antithrombogenic centrifugal blood pump, secondary flow, i.e., vortex and turbulent flow, must be properly controlled. An irregular stream pattern is a cause of hemolysis, and good wash-out around the shaft minimizes thrombus formation. In this study, flow visualization methods were applied to evaluate secondary flow in a centrifugal blood pump. Correlation with results of in vitro hemolysis tests was investigated. Separation of the stream lines from the vanes and patterns implying the existence of vortices were observed in the impeller that showed high hemolysis. By adjustment of vane angles, these irregular patterns could be minimized, and hemolysis decreased as well. Using a similar technique, the flow pattern at the back of the impeller could be visualized, which enabled further investigation of the effects of secondary flow on thrombus formation. This flow visualization was effective in examining secondary flow patterns.

Animals↗
PubMedDate not supplied

Characteristics of mixed venous oxygen saturation and physical activity as parameters for artificial heart control.

Mixed venous oxygen saturation (SvO2) and physical activity (PhyAc) are practical candidates as parameters of total artificial heart (TAH) control because SvO2 can be measured through a transparent blood pump housing with infrared rays and PhyAc can be calculated from signals of an accelerometer used for rate response pacemakers. Although the methods for measurement of the parameters have already been developed, characteristics of these parameters for TAH control, such as during exercise, are still unclear and were examined in this study. SvO2, cardiac output (CO), and PhyAc were measured as parameters. Multi-stage treadmill exercise tests were performed. Difference values (DVs) from the value at the start of exercise showed better correlation than did absolute values. Correlation coefficients between DV in CO and DV in SvO2 and between DV in CO and PhyAc were high at -0.82 and 0.72, while the time constants for the change of SvO2 and CO to the PhyAc change were 26 and 32 sec. Although the correlation coefficient between the CO and SvO2 was higher than that between CO and PhyAc, PhyAc responded more quickly to the speed change compared with the response of SvO2 and CO. It was concluded that SvO2 and PhyAc were useful parameters with different characteristics for TAH control during exercise.

Animals↗