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S Yokono

Publications and source records attributed to S Yokono.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Efficacy of ring-shape cover in active skin surface warming in neonates--a retrospective comparative study with conventional methods].

UNLABELLED: Prevention of perioperative hypothermia is one of the most essential factor for neonatal anesthesia. Recently the forced-air warming system has been considered the most effective method in preventing perioperative hypothermia in adults, in children, and in infants during maxillofacial operations. However, its use for abdominal or thoracic surgery in neonates has not been examined. In the present study, we studied the effects of the forced-air warmer with a ring-shape cover, and compared this method with the conventional method retrospectively. PATIENTS AND METHODS: Sixteen neonates, 13 for abdominal and 3 for thoracic surgery were anesthetized with oxygen-air (nitrous oxide) sevoflurane (isoflurane or enflurane) in combination with/without fentanyl. They were divided into two groups; one for forced-air warming (F-group), and another for conventional methods (C-group). The patients' mean age, height and weight, the duration of anesthesia, infusion rate (ml.kg-1.hr-1), and urine output did not differ each other. Patients in F-group were placed in the center of the ring-shape cover and received heated air from their surroundings. We did not use any other warming equipment or means except for an artificial nose and a warming mattress. "Medium" heated air (38 degrees C) or unheated, room temperature air were used when necessary. The operating room temperature was kept around 25 degrees C. Patients in the C-group were placed on a warming mattress and under an infrared radiant heater with the room temperature of 30 degrees C. Their extremities were covered with aluminum-foil. Rectal, deep forehead, and deep sole temperatures were monitored throughout anesthesia. RESULTS AND CONCLUSION: In F-group, temperatures were well maintained, while C-group failed to maintain. In F-group, the mean value of base excess at the beginning of the operation was -1.8 mM, but it was restored to normal level without administration of sodium bicarbonate. No complications were found. Thus, compared to conventional methods, the forced-air warming system with a ring-shaped cover is an efficient method for body temperature management in neonatal anesthesia.

Anesthesia, General↗
PubMed1996

[Acute alcoholism after ethanol fixation for ovarian chocolate cyst].

We experienced a case of acute alcoholism after ethanol fixation for ovarian chocolate cyst. A 46 year old female was scheduled for ethanol fixation for ovarian chocolate cyst. Ethanol fixation was performed with 110 ml of 99% ethanol under general anesthesia. Ethanol 70 ml was not removed. After the operation, patient did not emerge from anesthesia within 30 min. Blood alcohol concentration was 232 mg.dl-1. It is important to remove total ethanol used for ethanol fixation in anesthetic management for ethanol fixation for ovarian chocolate cyst.

Alcoholic Intoxication↗
PubMed1996

[Changes of urinary ulinastatin and serum CRP after elective surgery for gastric cancer].

Urinary ulinastatin (UTI) is elevated in various conditions, such as renal disease, myocardial infarction, neoplasm, leukemia and normal pregnancy. The purpose of the present study is to measure the change of UTI after surgery for gastric cancer and to compare with other acute phase reactants. Urine samples were collected from 7 surgical patients. UTI level was measured by radioimmunoassay and corrected by urinary level of creatinine. UTI levels began to increase from the first postoperative day and reached the maximum level on the third postoperative day. The pattern of UTI correlated with that of serum CRP levels. Meanwhile, when patient was in inflammatory condition postoperatively, UTI increased further and its pattern correlated with that of serum CRP levels. These results suggest that UTI is an acute phase reactant and a sensitive marker indicating the degree of inflammatory condition after surgery.

Acute-Phase Proteins↗
PubMed1996

[Postoperative urinary ulinastatin secretion and renal function in hepatectomized patients with and without liver cirrhosis].

We compared ulinastatin secretion into urine with renal function during postoperative period in three groups, hepatectomized group with liver cirrhosis (LC(+), n = 7), hepatectomized group without liver cirrhosis (LC(-), n = 4) and subtotal gastrectomized group with normal liver function (GR, n = 7). In LC(+) group, N-acetyl-beta-D-glucosaminidase (NAG) increased above normal upper limit throughout the postoperative period. Ulinastatin (UTI) also increased but the increase was not remarkable. In LC(-) group, NAG increase but not significantly compared with the preoperative value. UTI increased from 5.8 +/- 3.0 IU.mg x Cr-1 to 30.8 +/- 16.6 IU.mg x Cr-1 and 39.9 +/- 9.0 IU. mg x Cr-1 on the 1st and 3rd postoperative day respectively. In GR group, there was no change in NAG value. UTI on the 3rd postoperative day increased significantly (from 10.0 +/- 7.7 to 75.4 +/- 39.0 IU.mg x Cr-1). A small urinary secretion of UTI and increased NAG during postoperative period in LC(+) group suggest that UTI might play an important role in postoperative renal dysfunction in patients with liver cirrhosis.

Acetylglucosaminidase↗
PubMed1995

[Effects of ulinastatin on renal function after subrenal aortic cross-clamping].

Ten patients who had undergone temporary occlusion of the abdominal aorta below the origin of the renal arteries were studied to evaluate the effect of ulinastatin on the postoperative renal function after abdominal aortic cross-clamping. They were divided into two groups: ulinastatin group (ulinastatin 300,000 units.day-1 during intraoperative and postoperative three days, N = 5), control group (N = 5). In ulinastatin group, the increase of N-acetyl-beta-D-glucosaminidase on the third postoperative day was inhibited and renal function was well maintained. These results suggest that the administration of ulinastatin in perioperative day prevents postoperative renal dysfunction after abdominal aortic cross-clamping.

Acetylglucosaminidase↗
PubMed1995

[A case of beneficial effect of ulinastatin on postoperative renal function in a patient with acute renal failure].

We experienced a case in which ulinastatin may have been beneficial to improve postoperative renal function in a patient with acute renal failure. The patient had acute renal failure with serum Cr of 9.3 mg.dl-1 after nephrectomy. On the 14th postoperative day, he underwent laparotomy under diagnosis of ileus. Administration of ulinastatin, 300,000 units.day-1 for 4 days, increased urine volume and creatine clearance and improved serum Cr level. This case suggests that ulinastatin might exert a beneficial effect on the recovery from renal tubular damage and on the glomerular filtration ratio, with resultant improvement of acute renal failure.

Acute Kidney Injury↗
PubMed1995

[Effects of ulinastatin on postoperative renal function after cardiopulmonary bypass].

The effects of ulinastatin on postoperative renal function after the open cardiac surgery under cardiopulmonary bypass (CPB) were studied. N-acetyl-beta-D-glucosaminidase in urine as a marker of tubular function and serum creatinine rose significantly after CPB in the control group but not in the ulinastatin group. Ulinastatin was considered to be effective in protection of tubular function after CPB. In patient with poor preoperative renal function, ulinastatin prevented the deterioration of postoperative renal function by protecting tubular function.

Acute Kidney Injury↗
PubMed1995

[The support of postoperative renal function by ulinastatin in patients with preoperative renal dysfunction].

The principal perioperative management of patients with renal dysfunction is to prevent postoperative acute renal failure. Therefore, it is crucial to do all possible therapies by which its occurrence is prevented. We experienced three cases in which ulinastatin may have been beneficial to maintain postoperative renal function. The patients had preoperative renal dysfunction with serum Cr between 1.5 and 2.0 mg.dl-1. During the operation and for the three postoperative days, 300,000 units.day-1 of ulinastatin were administered intravenously. After the operation, serum Cr level was not elevated. Urine output and creatinine clearance increased. These three clinical cases suggest that ulinastatin may prevent the deterioration of postoperative renal function in patient with preoperative renal dysfunction.

Acute Kidney Injury↗
PubMed1994

Possible participation of NMDA and glycine receptors but not GABAA receptors in enflurane-induced opisthotonus in mice.

1. We previously reported that volatile anaesthetics produce incidences of a transient opisthotonus in mice, a sign of CNS stimulation. This study was performed to investigate mechanisms by which enflurane-induced opisthotonus (EIO) occurs. 2. The effects of pretreatment of N-methyl-D-aspartate (NMDA) antagonists dizocilpine (MK-801; DIZ) and ketamine (KET), GABAA antagonists picrotoxin (PIC), pentylenetetrazol (PTZ) and glycine antagonist strychnine (STR) on the incidence of EIO were determined. Prior to exposure to 2.0% enflurane in air, male ddN mice were given intraperitoneal injections of 0.2 mL saline (control), 0.5-5.0 mg/kg DIZ, 20-80 mg/kg KET, 2.9 mg/kg PIC, 40.0 mg/kg PTZ and 0.75 mg/kg STR. After the injection, the behavioural state of the mice was observed for 20 min (the pre-enflurane period). During the exposure to enflurane the time for immobilization, that is, anaesthetic induction time (IT), and the incidence of EIO were measured. 3. Dizocilpine (1.0-5.0 mg/kg) and KET (80 mg/kg) significantly (P < 0.01) reduced both the incidence of EIO and IT in a dose-dependent manner. During the pre-enflurane period DIZ produced incidences (5-40%) of transient seizures in a dose-dependent manner, while KET did not induce them at all. The two GABAA antagonists had no detectable effect on the EIO. Strychnine significantly enhanced the EIO. These CNS stimulants resulted in a 3-10% incidence of transient seizure and/or opisthotonus during the pre-enflurane period, but there was no correlation between DIZ-induced seizure and EIO. 4. These results suggest that the EIO is mediated by the NMDA and the STR-sensitive glycine receptors, but not the GABAA receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Anaesthetic mechanism--from molecular to biological aspects.

The mechanism of anaesthesia is still a black box, although many investigators have been concerned about this theme since the 19th century. It is too complex to clarify the mode of anaesthetic action, as a variety of compounds have been adopted as anaesthetics. Hill coefficients calculated from the righting reflex dose-response curve in enflurane, isoflurane sevoflurane and halothane anaesthesia in a certain strain of mice were from 14 to 56. It shows that many factors are related to the mechanisms of anaesthetic actions. In this review, we adduce from our previous studies 2 approaches to study the anaesthetic mechanism. The pharmacogenetical approach is concerned with the mode of genetics in anaesthetic sensitivities in ddN and C57BL, 2 strains of mice and their hybrids, and distributions of neurotransmitters in each mouse brain. The sensitivity rates in enflurane and isoflurane anaesthesia are both 1.4 between ddN and C57BL. The rate is highest compared with precedent data. The F1 males from ddN females x C57BL males had a significantly higher ED50 than F1 males from the reciprocal crosses for both enflurane and isoflurane, indicating that enflurane resistance and isoflurane resistance are controlled by genes on the sex (X) chromosome. In the F2 progeny, we hypothesized that 1 gene was on the X chromosome and another gene was on the autosome. Although there were several differences among ddN, C57BL and their hybrids and several anaesthetics concerning distributions of neurotransmitters, neuropeptide Y, serotonine and methionine-enkephalin in the mouse brain, the relationship to the genetical analysis has been chaotic. The physicochemical approach is concerned with the confirmation of the action site of volatile anaesthetics in phospholipid bilayer membranes. It is suspected from Overton's experiment that the action site is not in the core of lipid bilayer but on the surface of membrane. It was demonstrated by 2 methodologies. Two-dimensional nuclear Overhauser effect spectrum in H1-NMR spectra of dipalmitoyl phosphatidylcholine (DPPC) vesicle membrane in the presence of methoxyflurane revealed from the existence of the cross-peak between the methoxy-proton and the choline methyl-proton that methoxyflurane molecule interacted only to the polar head of lipid membrane at lower temperatures.(ABSTRACT TRUNCATED AT 400 WORDS)

Anesthetics, Inhalation↗
PubMed1993

Strain-differences of sensitivity to volatile anesthetics and their genetic character in mice.

Using loss of the righting reflex, we determined the ED50 values for enflurane, isoflurane, sevoflurane and halothane in white-haired ddN mice and black-haired C57BL mice. The ED50s (Mean +/- SEM) in ddN and C57BL mice for enflurane were 1.65 +/- 0.01 and 1.19 +/- 0.01% atm, for isoflurane 1.02 +/- 0.01 and 0.74 +/- 0.01% atm, for sevoflurane 2.29 +/- 0.03 and 1.95 +/- 0.03% atm, and for halothane 0.97 +/- 0.01 and 0.97 +/- 0.01% atm, respectively. The results indicate that the ddN strain is more resistant to enflurane, isoflurane and sevoflurane than the C57BL strain. The sensitivities to enflurane and isoflurane is F1 progeny of reciprocal crosses between ddN and C57BL mice revealed that in the ddN strain enflurane resistance is an incompletely dominant or polygenic character, isoflurane resistance in ddN strain is an autosomal recessive character and both are controlled by genes on the sex (X) chromosome. Enflurane and isoflurane resistances are controlled by at least 2 genes, one on the X chromosome, and each resistance is controlled by a different genetic mode

Journal Article↗
PubMed1993

Memory facilitation by posttraining exposure to halothane, enflurane, and isoflurane in ddN mice.

The effect of low and high concentrations of halothane, enflurane, and isoflurane on posttraining memory function was studied in male ddN mice. Mice were trained to escape an aversive electric foot shock as an unconditioned stimulus within 3 s after being exposed to light and a buzzer as a conditioned stimulus. Immediately after training (first session: 30 trials), the animals were exposed to halothane, enflurane, or isoflurane for 120 min and then were tested again on the avoidance task (second session: 30 trials) 22 h after cessation of exposure. The performance ratios, [B/A] (i.e., A is the score in the first session, and B the score in the second) were compared between the anesthetized groups and their respective control (nonanesthetized) groups. Mean performance ratios in the control groups ([B/A]c) ranged from 136.8% to 163.9% and those in the anesthetized groups ([B/A]a) ranged from 151.4% to 174.7%. [B/A] in each anesthetized group exceeded [B/A] in its corresponding control group. [B/A]a significantly exceeded [B/A]c by 13.1% in the 1.23 minimum alveolar concentration (MAC) enflurane group (P < 0.05) and by 12.4% in the 0.29 MAC isoflurane group (P < 0.05). These results suggest that posttraining exposure to volatile anesthetics facilitates memory.

Animals↗
PubMed1993

[Effects of ulinastatin on rat renal energy metabolism around ischemia studied by 31P MRS].

The effects of ulinastatin (UTI) on rat renal energy metabolism during ischemia and reperfusion were studied by 31P nuclear magnetic resonance spectroscopy (31P MRS) in vivo. Rat kidney was exposed to ischemia for 30 min by clamping the abdominal aorta above the renal arteries. Pre-ischemic administration of UTI inhibited the decline of intracellular pH (pHi) during ischemia and improved the recovery of renal energy metabolism and pHi after reperfusion. This result suggests that UTI might inhibit anaerobic metabolism during renal ischemia and an improve energy metabolism during reperfusion. 31P MRS provided a unique tool to study intact cellular function continuously in noninvasive fashion, allowing assessment of metabolic function during ischemia and after reperfusion.

Animals↗
PubMed1993

[Beneficial effect of bromocriptine in a patient with malignant syndrome and hepatic dysfunctions].

A 39 year-old male, diagnosed as meningoencephalitis, was admitted because of the development of malignant syndrome. This syndrome appeared to have resulted from anti-psychotic drugs given to relieve excitement and insomnia. As he had hepatic dysfunctions, we could not administer dantrolene further. Therefore, we gave bromocriptine to ameliorate the symptoms such as muscle rigidity or hemodynamic perturbations. Thereafter, the patient gradually became stable in hemodynamics and in other symptoms. In addition, a further deterioration in hepatic functions did not occur with administration of bromocriptine. The case suggests that in patients with malignant syndrome associated with hepatic dysfunctions, bromocriptine could be a first choice as a pharmacological treatment of the syndrome.

Adult↗
PubMed1992

Interactions between volatile anesthetics and dipalmitoyl phosphatidylcholine liposomes as studied by fluorometry with a thiacarbocyanine dye.

The effects of volatile anesthetics on the properties of dipalmitoyl phosphatidylcholine liposome were investigated by fluorescence spectroscopy with a thiacarbocyanine dye (3,3"-dioctadecyl-2,2"-thiacarbocyanine) which is sensitive to the viscosity and the dielectric constant of the environment. Seven volatile anesthetics, halothane, enflurane, isoflurane, methoxyflurane, sevoflurane, diethylether and chloroform were used. All anesthetics decreased the phase transition temperature of the liposome and increased the effective dielectric constant of the water-liposome interface. The increase of the effective dielectric constant was attributed to the release of the hydrated water molecules from the membrane surface. The increment of the effective dielectric constant depended on the thermodynamic activity of anesthetics in the solution, and was not affected seriously by the kind of anesthetics. On the other hand, the degree of the depression of the phase transition temperature depended on the molar concentrations of anesthetics. Considering from the Ferguson's report, which is dealt with the relationship between the physiological effect and the thermodynamic activity, the effect of anesthetics on the effective dielectric constant of the membrane surface is more correlated to the anesthetic action than the effect on the phase transition temperature.

Journal Article↗
PubMed1992

Effects of high pressure on polarity change of the water-liposome interface induced by volatile anesthetics.

The effects of high pressure on the interactions between volatile anesthetics and three kinds of phosphatidyl choline liposomes were investigated by fluorometry, using a thiacarbocyanine dye (3,3"-dioctadecyl-2,2"-thiacarbocyanine) which is sensitive to the environmental viscosity and dielectric constant. Seven general anesthetics, halothane, enflurane, isoflurane, methoxyflurane, sevoflurane, diethylether and chloroform were used. We have previously reported that these anesthetics decreased the phase transition temperature and increased the effective dielectric constant of the water-liposome interface using dipalmitoyl-phosphatidylcholine. In this study, it was confirmed that the effects of anesthetics on the effective dielectric constant were not altered by the use of a gel or liquidcrystal membrane, and were reversed by the application of high pressure (<800 bars). The increase of the effective dielectric constant was attributed to the perturbation of hydrogen bonds at the liposomal interface. High pressure is considered to promote hydration. Our results obtained under high pressure supported previous observations made at ambient pressure, which suggested that the perturbation of hydrogen bonds at the water-liposome interface correlates with the mechanism of anesthesia.

Journal Article↗
PubMed1992

Local anesthetic-sensitive electrodes: preparation of coated-wire electrodes and their basic properties in vitro.

Coated-wire electrodes with local anesthetic (LA) cation-selective membranes were prepared, and their properties in vitro were investigated. Copper wires (0.8-mm diameter) were coated with gel membranes of 110 mg of poly(vinyl chloride), 5 mg of ion pairs of tetraphenylborate anion with LA cation, 100 mg of dioctylphtalate, and 1.5 mL of tetrahydrofuran. This was the composition determined to be most suitable. Their electromotive force relative to an Ag/AgCl electrode was measured in LA solutions. The lidocaine, dibucaine, and mepivacaine electrodes all showed good Nernstian response at 25 degrees C in aqueous solutions in the concentration ranges of 1 x 10(-4) to 1 x 10(-2) mol/L, 4 x 10(-5) to 1 x 10(-2) mol/L, and 5 x 10(-5) to 1 x 10(-2) mol/L, respectively. The response time was within 10 s. The electrode potential decreased as the pH in the solution increased, with a corresponding decrease of the protonated form of LA. The hydrophobic nature of the LA was closely related to the electromotive force and to the selectivity of the electrode toward various LA cations. Dibucaine, the most hydrophobic, had the highest electrode potential. The more hydrophobic the LA of the electrode, the less it is interfered with by other LA molecules. The more hydrophobic the interferent cation, the more it acts on the electrode potential. The electrode system could also measure LA in human plasma at 37 degrees C, although the responsiveness was depressed in the low concentration range owing to binding of LA to the serum protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthetics, Local↗