Biomedical subjects

W Ueda

Publications and source records attributed to W Ueda.

At least 55 records · Page 3Linked to original sources

PubMed1991

[The CO2 absorption capacity and color indication of a newly developed soda lime (Wakolime)].

The CO2 absorption capacity and the color change of ethyl violet (color indicator) of Wakolime A (newer type). Wakolime (older type), and Sorb 800 were studied under the clinical anesthetic condition. A two chamber canister was filled with soda lime and anesthetic gas flowed upward through the canister at the rate of 4 ml.min-1. The wall temperature of each chamber was measured with surface temperature sensing device. After 30 hours of use, the colored soda lime in the first chamber was examined with a color analyzer. The change of wall temperature indicated that the CO2 absorption capacity of Sorb 800 was the largest and that of Wakolime was the smallest among the three. The indicator color of both Wakolime A and Sorb 800 was clearer and of more vivid violet than that of Wakolime, which was dull and grayish. These results indicated that Wakolime A is superior in the CO2 absorption capacity and color indication to Wakolime.

Absorption↗

PubMed1991

[Convenient and useful computer software for the anesthesiologist].

Convenient and useful computer software for the anesthesiologist to draw figures for presentation, or to perform statistical analysis were presented. Each software is selected in the condition that it does not need special optional hardware, and processes the data quickly even with an old type computer, and also that even a computer beginner can easily operate it. The presented software are as follows: 1) Silhouette (drawing figures), 2) NEO (drawing figures), 3) Graph note (drawing figures), 4) Chart up science (drawing figures), 5) Z's word JG (making slide manuscripts) and 6) Biostat (doing statistical analysis).

Anesthesiology↗

PubMed1991

[The hemodynamic and metabolic changes following tourniquet release during halothane anesthesia].

We measured the hemodynamic and metabolic changes following the release of lower limb tourniquet during halothane anesthesia, and discussed the cause of reduction in the blood pressure and the effective method for prevention. Cardiac index decreased transiently following the release, and gradually increased afterward. Systemic vascular resistance index decreased continuously and progressively until 10 minutes after the release. These results indicate that the causative factors of reduction in the blood pressure are temporary decrease in cardiac output and subsequent decrease in systemic vascular resistance. In mixed venous blood, pH decreased, PCO2 increased and HCO3- remained unchanged after the release. It seems that pH reduction was chiefly caused by the increase in PO2. Thus, the preventive method for reduction in the blood pressure following the tourniquet release may be as follows; 1) intravenous fluid loading, 2) hyperventilation, 3) elevation of lower limb, 4) lightning the anesthesia, and 5) finally giving vasopressors.

Anesthesia, Inhalation↗

PubMed1991

[Determination of fentanyl concentrations in the blood with the application of high performance liquid chromatography].

We developed a method to determine the blood concentration of fentanyl by using reverse phase partition liquid chromatography. The extract rate of fentanyl from blood 10 ml was 79 +/- 2%, and the minimum detective concentration of fentanyl was 158 pg.ml-1. These performances are sufficient to determine the blood concentration of fentanyl in clinical anesthesia.

Anesthesiology↗

PubMed1990

Halothane enhances the phosphorylation of H1 histone and rat brain cytoplasmic proteins by protein kinase C.

The effect of halothane, a typical volatile anesthetic, on the calcium- and phospholipid-dependent protein kinase (PKC), which is one of the key enzymes of membrane signal transduction, was examined. PKC was partially purified from the cerebral tissue of male Wistar rats. Halothane increased PKC-mediated phosphorylation of calf thymus H1 histone in the presence or absence of phorbol ester or diolein, and also increased phosphorylation of the rat brain cytosolic proteins (47 kDa and 80 kDa). A similar but slight increase in H1 histone phosphorylation was observed with isoflurane and enflurane, less lipid soluble volatile anesthetics. These findings suggest that halothane may increase PKC-mediated phosphorylation by the modification of phospholipid membrane and affect membrane signal transduction of the nerve cell under the anesthetic state.

Animals↗

PubMed1990

Halothane impairs the bioenergetic functions of isolated rat liver mitochondria.

The effect of halothane, a potent and popular volatile anesthetic, on isolated rat liver mitochondria was examined. Halothane inhibited state 3 and dinitrophenol-induced uncoupled respiration with NAD(+)-linked substrates, but not with FAD-linked substrates, and did not affect the oxidation-reduction state of mitochondrial cytochromes. Moreover, halothane increased state 4 respiration and ATPase activity and decreased the extra-mitochrondrial pH change coupled to ATP synthesis. These results indicate that halothane impairs mitochondrial ATP production by interfering with both the electron transport from NAD+ to FAD and the coupling of oxidative phosphorylation. Halothane only slightly affected the membrane potential, which is commonly dissipated by typical classical uncouplers. Moreover, halothane inhibited both ATP-driven and respiration-driven Ca2+ accumulation in mitochondria and stimulated Ca2+ release from mitochondrial stores at concentrations higher than those at which it inhibited ATP production. These findings indicate that the uncoupling action of halothane is not classical. During halothane anesthesia, these mitochondrial abnormalities may contribute to hepatocyte dysfunctions.

Adenosine Triphosphatases↗

PubMed1990

Lidocaine inhibits stimulation-coupled responses of neutrophils and protein kinase C activity.

The effects of lidocaine, a local anesthetic, on various stimulation-coupled responses of neutrophils were studied. Superoxide generation, generation of chemiluminescence, depolarization of membrane potential and transitional increase in intracellular Ca2+ were inhibited by lidocaine in a concentration dependent manner. Lidocaine also inhibited Ca(2+)-activated phospholipid-dependent protein kinase (PKC) in the presence of various concentrations of Ca2+, phosphatidylserine and dioleoylglycerol. For the inhibition of all these stimulation-coupled responses, a similar order of the lidocaine concentration was needed. As in the case of dibucaine (Mori, T., Takai, Y., Minakuchi, R., Yu, B. and Nishizuka, Y., J. Biol. Chem. 255:8378-8380, 1980), lidocaine inhibited PKC activity in a manner competitive with phosphatidylserine. Lidocaine also inhibited the phosphorylation of 47 kDa neutrophil cytosplasmic protein, a phosphorylated protein required for NADPH oxidase activation. Thus, the cellular membrane phospholipid may be one of the target sites of lidocaine for the inhibitory action on the various stimulation-coupled responses of neutrophils, and these effects of lidocaine may correlate with its inhibitory action on PKC activity.

Animals↗

PubMed1990

[Liquid crystal thermography; a reliable method for detecting soda lime exhaustion].

The dynamic and functional state of soda lime can be more precisely assessed by measuring changes in wall temperatures of the absorption chambers rather than observing color change of the soda lime granules. We demonstrated in this report that the liquid crystal thermometer is an inexpensive and reliable measuring device for this purpose.

Anesthesiology↗

PubMed1990

[Effect of isoflurane and enflurane on ICG-clearance].

We performed ICG-test (indo-cyanine green test) during surgery to study the effect of isoflurane and enflurane on ICG clearance in human. When the systolic arterial pressure (SAP) was maintained at 70% of the preoperative base line value, a significant decrease in ICG clearance occurred in the patients who received enflurane. Isoflurane, on the contrary, did not cause such a decrease in the ICG clearance. We conclude that isoflurane may restore either the blood flow to the liver or the liver function and the liver may remove ICG from the blood much better under isoflurane than under enflurane.

Adult↗

PubMed1990

[Let's study pharmacokinetics related to anesthesiology by using computer graphics: inhalation anesthetics].

The pharmacokinetics of inhalation anesthetics has been out of public interest for 20 years. Partition coefficient or solubility of anesthetic, an important determinant of uptake and distribution of inhaled anesthetics, may be the only remains of the pharmacokinetics of inhaled anesthetics. There still, however, are a few evidences which can not be explained by partition coefficient of anesthetic. The authors applied three compartment model to the rise of the blood concentration of anesthetics, i.e., nitrous oxide, enflurane, halothane, and diethyl ether. We revealed that the change in the blood anesthetic concentration may be related to the size of compartments and their time constants. The size of compartments and their time constants may be determined by interaction of partition coefficient of anesthetic and blood distribution to the tissues which may be different with different anesthetic, and may also be different when the blood concentration of anesthetic is different.

Anesthesia, Inhalation↗

PubMed1990

[Anesthetic care of a patient intoxicated with thinner].

This is a report of a 28 year old male who underwent emergency laparotomy. He had a history of asthma and chronic abuse of thinner (toluene), and he stabbed himself after acute intoxication by the drug. Anesthesia was induced and maintained by halothane and oxygen. Vecuronium was used for muscle relaxation. Abnormal EKG was seen during perioperative period: A-V dissociation and incomplete RBBB. After emergence from anesthesia, so called "flash back" phenomenon was observed but this was controlled by diazepam. Since the chronic abuse of toluene causes organic changes in many vital organs, we must take special precautions when we anesthetize a patient with thinner intoxication: (1) toluene has a negative inotropic effect and also delays the S-A and A-V conduction rate, which may potentiate the cardiac effect of inhalation anesthetics; (2) toluene causes liver damages; and (3) the patient may experience "flash back" phenomenon.

Adult↗

PubMed1990

[Interaction of halothane and PGE1 on ICG excretion].

We performed ICG-test during surgery to study the effect of halothane on ICG excretion in humans. We also evaluated the effect of PGE1 on ICG excretion concomitantly used during halothane anesthesia. A significant decrease in ICG clearance occurred in the patients who received only halothane to reduce the systolic arterial pressure (SAP) to 70% of the preoperative value. The reduction in SAP induced by PGE1 together with halothane, however, did not decrease the ICG clearance rate. We conclude that halothane may decrease the hepatic blood flow, but PGE1 may neutralize the effect of halothane, and maintain the hepatic blood flow in man.

Adult↗

PubMed1989

Hemodynamic effect of epidurally administered epinephrine in middle-aged and elderly patients.

The circulatory effects of epinephrine, added to local anesthetic, during epidural analgesia were compared between middle-aged (52-65 years) and elderly (75-82 years) patients undergoing transurethral resection of the prostate. We used 10 ml of 1.5% lidocaine with or without 1:200,000 epinephrine. The plasma epinephrine concentration peaked 5-10 min after the injection in the patients who received epinephrine with anesthetic. There was no significant difference in the plasma epinephrine concentration between the two age groups. Epinephrine caused a significant increase in the heart rate and a significant reduction in the diastolic arterial pressure in both age groups. A significant reduction of the systolic arterial pressure, however, occurred only in the middle-aged patients. Neither the plasma concentration of endogenous epinephrine, heart rate nor arterial pressure changed significantly in the patients who received plain lidocaine. We conclude that the increase in the heart rate and decrease in the diastolic arterial pressure induced by epinephrine when added to an analgesic may not be influenced by advancing age. In contrast, the reduction in the systolic arterial pressure caused by epinephrine may become less pronounced with age.

Aged↗

PubMed1989

Heat generation as an index of exhaustion of soda lime.

The wall temperatures of the absorptive chambers of a divided soda lime canister were measured in 70 patients to determine the relationship between the difference in temperature of the two chambers and CO2 passage through the first chamber. CO2 passage through the first chamber was detected when the temperature of the second chamber became equal to that of the first. A significant correlation (R = 0.94; P less than 0.001) was found between the magnitude of CO2 passage through the first chamber and the difference in temperature between the chambers. When the maximal absorptive capacity of soda lime was reached, the pH of the surface of soda lime granules was still too high to change the indicator color. Exhaustion of soda lime is more reliably recognized by measuring wall temperatures of the chambers than by observing color change of the soda lime granules.

Adsorption↗

PubMed1989

[Let's study pharmacokinetics related to anesthesiology by using computer graphics: intravenous drugs].

The pharmacokinetics of intravenous drugs used during anesthesia provides us important information for patients' care. The pharmacokinetic data are usually shown in a graphic expression together with numerical values. The numerical values are only convenient for investigators in exchanging their knowledge and information. The graphic data contain, however, whole and real information obtained in a pharmacokinetic study. The authors demonstrated a way to derive information from graphic data, which is practically applicable for patients' care. We also showed a way to calculate numerical values from graphic data by using "graphnote" by Fukutake Pub. Co. We believe that our manual way to calculate numerical values from graphic data, with an aid of computer graphics combined with scientific calculator, helps us to understand the invisible processes performed inside "a black box" or a computer installed with a commercially available soft ware for the pharmacokinetics.

Anesthesia, Intravenous↗

PubMed1989

[Let's study exponential function related to anesthesiology by using computer graphics--Part I: Wash-out exponential function].

A computer simulation is used to analyze physical or biophysical changes related to anesthesiology mostly by computer oriented experts. Recent development in a personal computer and its program, however, has made it possible for more anesthesiologists to have an experience of computer analysis. For example, graphic expression of exponential functions can easily be obtained by using a computer program, such as "Graphnote" by Fukutake Pub. Co. In this literature, the author first explained the wash-out exponential function. Then estimation of changes in the hematocrit and serum protein concentration associated with blood loss during surgery was given as an example of biophysical phenomena related to anesthesiology, to which the wash-out exponential function is applicable for mathematical simulation. Besides, the author demonstrated the way to draw exponential function curves by using "Graphnote", so that the readers can express the curves by themselves.

Anesthesia↗

PubMed1989

[Let's study exponential function related to anesthesiology by using computer graphics--Part II: Wash-in exponential function].

The author first explained the wash-in exponential function. Then mathematically simulated changes in the concentration of inhalation anesthetic inside a breathing circle during induction of anesthesia were shown as a physical model related to anesthesiology to explain the idea of wash-in exponential function. Effect of the flow rate and concentration of anesthetic delivered to a breathing circle on the changes in the anesthetic concentration inhaled by patients was calculated and graphed by using a computer program developed for science education. The author also stressed the importance of graphic expression in understanding various physical or biophysical phenomena related to anesthesiology.

Anesthesia, Closed-Circuit↗

PubMed1988

Halothane, an inhalation anesthetic, activates protein kinase C and superoxide generation by neutrophils.

The rate of superoxide generation of guinea pig intraperitoneal neutrophils by a chemotactic peptide or 12-O-tetradecanoylphorbol-13-acetate (TPA) was increased by 2-bromo-2-chloro-1,1,1,-trifluoroethane (halothane), an inhalation anesthetic. This increase was inhibited by 1-(5-isoquinolinesulfonyl)methylpiperazine dihydrochloride (H-7), a specific inhibitor of Ca2+- and phospholipid-dependent protein kinase C (PKC). Halothane was found to significantly activate partially purified PKC. The activation required phosphatidylserine (PS) and Ca2+. Dioleoylglycerol- or TPA-activated PKC activity was further increased by halothane. The cytoplasmic proteins of guinea pig neutrophils phosphorylated by halothane-activated PKC were similar to those phosphorylated by PMA-activated PKC. The phosphorylation of a 48 kDa protein, a phosphorylated protein required for NADPH oxidase activation, was also increased by halothane. These data suggest that the increase of superoxide production by halothane is correlated with its activation of PKC.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗