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Biomedical subjects

K Suwa

Publications and source records attributed to K Suwa.

At least 19 recordsLinked to original sources
PubMed1992

Mechanism of inhibitory action of ketone bodies on the production of reactive oxygen intermediates (ROIS) by polymorphonuclear leukocytes.

We determined an effect of acetoacetic acid (AcAc) and 3-hydroxybutyrate (3-OHB) on the production of reactive oxygen intermediates (ROIs) in polymorphonuclear leukocytes from healthy volunteers. Both AcAc and 3-OHB inhibited the luminol-dependent chemiluminescence (LDCL) activities assessed with initial slope and the inhibition rates were about 42%, 44% respectively by AcAc and 3-OHB when the leukocytes were preincubated with 10 mM AcAc or 3-OHB for 60 minutes. The LDCL activity was reduced by 16% and 42% following the addition of 1mM and 10 mM AcAc. The similar reduction of the LDCL activity was observed in the addition of 3-OHB. Either 3-OHB or AcAc failed to show a significant reduction of myeloperoxidase (MPO) activity. However, both 3-OHB and AcAc dose-dependently inhibited superoxide anion (O2-) production, measured by using cytochrome c. These data provided evidence that both 3-OHB and AcAc suppress neutrophil oxidative metabolism with respect with O2- production.

3-Hydroxybutyric Acid↗
PubMed1992

MPO activity and generation of active O2 species in leukocytes from poorly controlled diabetic patients.

OBJECTIVE: This study was undertaken to determine which part of ROI generation is reduced in the neutrophils from patients with NIDDM. RESEARCH DESIGN AND METHODS: Superoxide anion (O2-) production, LDCL activity in response to opsonized zymosan, and MPO activity were measured in leukocytes of poorly controlled NIDDM patients (FBG greater than 8.89 mM, HbA1 greater than 10%). RESULTS: In diabetic subjects, both O2- production and LDCL activity assessed with initial slope gradient and peak value were significantly reduced. MPO activity was also decreased in diabetic subjects, and there was a significant correlation between HbA1 levels and MPO activity of diabetic subjects. CONCLUSIONS: This study demonstrated that every step in leukocyte ROI generation should be reduced in the leukocytes from poorly controlled diabetic patients.

Adult↗
PubMed1992

[Simulation in anesthesia].

Simulation in anesthesia is reviewed. Its aim includes education/training, analysis of phenomena, explanation or interpretation of phenomena and instrument checks. It deals with pharmacokinetics/pharmacodynamics of inhalational and intravenous agents, respiration and circulation, action and behavior of anesthesiologists and income analysis. Simulations are accomplished mainly by using computers, yet few use physical models or a physical model combined with computers. For writing this review, CD-ROM's of Medline data were used. Problems in searching literatures through this route are discussed. Finally, the problem of the distribution of softwares is also discussed.

Anesthesiology↗
PubMed1992

[Acid-base disorders in anesthesiology and in related fields].

Acid-Base disorders in anesthesia and in related fields were discussed. Four topics were chosen because they are relatively new and attracting attentions. They are 1) Monitoring Petco2 in anesthesia and in Intensive Care, 2) Relationships between newly established laparoscopic surgery and ventilatory impairment/elevation of Paco2, 3) Surgery in which large amount of chloride ion is absorbed, and 4) High venous Pco2 in resuscitation.

Acid-Base Imbalance↗
PubMed1991

[Weaning and chest wall mechanics].

I discussed following four points. 1. Weaning means an increase in energy demand. For successful weaning, stable hemodynamics and good nutrition are mandatory. 2. Success or failure is closely related with the "reserve" factors of the patients, including those discussed in 1. These "reserve" factors may be difficult to evaluate from the spirometry/pulmonary function data only. 3. A dissociative movement between chest wall and abdomen indicates that the weaning is likely to fail. The data, however, are inconclusive. 4. Few occasional patients are successfully weaned by the classical on-off method, after failing to be weaned by the standard IMV. We interpret that the classical on-off method has more elements of training. This point should be taken into consideration and this aspect of training should be pursued for weaning.

Biomechanical Phenomena↗
PubMed1991

[Experience in using personal computers in writing and publishing books].

Experiences in using personal computers in writing and publishing books are presented. Since 1984, I have written 8 books, translated 4, and edited two books, in all of which personal computers/wordprocessors have been somehow involved. Their relationships to computers were; writing using a wordprocessor, drawing graphs and figures by computers, writing books about computers and doing analysis using them, such as acid-base and uptake of inhalational anesthetics. In ten books out of these 14, the printings of text were done electronically from diskettes. This has decreased greatly the work of the author's galley-proof reading. The greatest advantage of the computers/wordprocessors is that they make personal editing possible, thereby compiling materials, writing them into books and improving grammar and wording.

Anesthesiology↗
PubMed1989

Phasic capillary pressure determined by arterial occlusion in intact dog lung lobes.

In six open-chest dogs, electrocardiogram- (ECG) controlled pulmonary arterial occlusion was performed during the control period and during the infusions of serotonin and histamine. A temporal series of instantaneous pulmonary capillary pressure and the longitudinal distributions of vascular resistance and compliance were evaluated in the intact left lower lung lobe. In the control period, we found a significant phasic variation of pulmonary capillary pressure (Pc) with the cardiac cycle. The ratio of arterial to venous resistances (Ra/Rv) was 6:4, and the ratio of arterial to capillary compliances (Ca/Cc) was 1:11. During the infusions of serotonin and histamine, Pc showed similar phasic variations, despite significant hemodynamic changes induced by these agents. Serotonin predominantly increased Ra, whereas histamine predominantly increased Rv. The ratio of Rv to the total resistance decreased significantly from 0.42 to 0.32 during the infusion of serotonin and increased significantly to 0.62 during the infusion of histamine. The data suggest that phasic Pc determined by ECG-controlled arterial occlusion reflects the pulsatility in the pulmonary microvascular bed under control conditions and after alterations of the pulmonary vascular resistance by serotonin and histamine.

Animals↗
PubMed1989

Ventricular premature contraction after repair of tetralogy of Fallot--the influence of postoperative factors, particularly the right ventricular regional wall motion.

The presence and severity of ventricular premature contraction (VPC) in 35 patients with tetralogy of Fallot (TF) were studied, 5 to 10 years after intracardiac repair (ICR), using treadmill exercise testing and 24-hour ambulatory monitoring. VPCs were observed in 24 patients (68.6%). The patients were classified into two groups according to the types of VPCs: group A (23 patients) without VPCs or with VPCs of Lown's grade 1 and group B (12 patients) with VPCs of Lown's grade 2, 3 or 4. Group B patients were found to have significantly higher right to left ventricular peak-systolic pressure ratios and higher right ventricular peak systolic pressures than those of group A. But there were no significant differences between the two groups in operative age, the time lapse between ICR and evaluation, the duration of exercise and so on. Group B patients also showed significantly decreased right ventricular regional wall motions in the right ventricular outflow tracts (ROTs), indicating akinetic or paradoxical movements than group A patients. It is thought that postoperative right ventricular hypertension and the akinetic or paradoxical wall movement of the ROT may have some effect on the genesis of postoperative VPCs after repair of TF.

Cardiac Complexes, Premature↗
PubMed1989

[Analysis of relative cerebral perfusion in ischemic cerebral diseases by single photon emission computed tomography using N-isopropyl-p-[123I]iodoamphetamine].

Semiquantitative analysis of 123I-IMP SPECT enabled to evaluate relative regional cerebral perfusion and redistribution rates. Two parameters were calculated; the relative perfusion rate (RPR) is the ratio of radioactivity on a localized lesion divided by radioactivity on the visual cortex, the redistribution rate (RR) is the ratio of RPR in late images at 3 hrs divided by that in early images at 15 min postinjection. Total of 45 patients with ischemic cerebral diseases were studied. There were 29 males and 16 females with the age ranging from 37 yr to 80 yr. The RPRs were 81.3 +/- 5.1% in TIA (14 cases), 63.6 +/- 10.6% in RIND (8 cases), 64.6 +/- 8.5% in mild infarction (9 cases) and 40.2 +/- 13.8% in severe infarction (14 cases). RPR on the lesion of the severe infarction was extremely low compared to that of TIA, RIND and mild infarction. RPRs of lesions in the mild and severe infarction were reversely correlated to the size of LDA on X-ray CT (p less than 0.01). RPR was well correlated to clinical status of ischemic diseases. The RRs were 1.18 +/- 0.08 in TIA, 1.41 +/- 0.20 in RIND, 1.28 +/- 0.15 in mild infarction and 1.21 +/- 0.31 in severe infarction. The RR of RIND was significantly higher than those of other categorized groups (p less than 0.01). The RR may prove useful as a parameter reflecting tissue viability in cerebral ischemic diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Respiratory emergencies].

Respiratory emergencies were investigated from those occurring during anesthesia, especially with regard to safety measures. Causes included; errors in FiO2, circuit disconnections, and airway difficulties. For FiO2 errors, several specific patterns are known, and a few of those can now be prevented by using specific safety features. The disconnection alarm is not widely used in Japan. Maintaining good airways is not always easy and universally applicable measures are yet to be developed. The availability of fiberoptic bronchoscopes may promote safety in this regard.

Accident Prevention↗
PubMed1989

[Comparison of O2 saturation measurements by oximetry and by gas analysis].

For checking the reliability of pulse oximetry in the operating rooms, we compared values of arterial O2 saturation measured by a blood gas analyzer (SAT) with values monitored by pulse oximetry (SaO2). SaO2's were found to be significantly different from SAT's. The regression equation was SAT = 0.31 X SaO2 + 68.4 and the correlation coefficient was 0.66. P value of paired comparison was 0.0001 indicating that the two sets of values were not equal to each other. When one observer performed a similar study using a high-fidelity pulse oximeter, SaO2's were not different from SAT's. The regression equation in this case was SAT = 0.85 X SaO2 + 15.0 and the correlation coefficient was 0.95. P value of paired comparison was 0.3244. The reliability of pulse oximetry differs from one anesthesiologist to another and depends upon the accuracy of each pulse oximeter. In clinical experiment, using the data by pulse oximetry in operating room is misleading.

Blood Gas Analysis↗
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↗