Influence of Ethyl Caproate on the Size of Lipid Vesicles and Yeast Cells.

Ethyl caproate (EC) is a key flavor component of sake. Recently, in sake brewing, an effort has been underway to increase the content of aromatic components such as EC. However, the function of EC in yeast cells remains poorly understood. Therefore, we investigated the effects of EC using cell-sized lipid vesicles. We found that vesicle size decreases in a concentration-dependent manner when EC is contained in lipid vesicles. Furthermore, yeast experiments showed that a strain producing high quantities of EC in its stationary phase decreased in size during EC production. Given caproic acid's (CA) status as the esterification precursor of EC in yeast, we also compared lipid vesicles containing CA with those containing EC. We found that CA vesicles were smaller than EC vesicles of the same concentration. These results suggest that EC production may function apparently to maintain cell size.

Three gene expression vector sets for concurrently expressing multiple genes in Saccharomyces cerevisiae.

Yeast has the potential to be used in bulk-scale fermentative production of fuels and chemicals due to its tolerance for low pH and robustness for autolysis. However, expression of multiple external genes in one host yeast strain is considerably labor-intensive due to the lack of polycistronic transcription. To promote the metabolic engineering of yeast, we generated systematic and convenient genetic engineering tools to express multiple genes in Saccharomyces cerevisiae. We constructed a series of multi-copy and integration vector sets for concurrently expressing two or three genes in S. cerevisiae by embedding three classical promoters. The comparative expression capabilities of the constructed vectors were monitored with green fluorescent protein, and the concurrent expression of genes was monitored with three different fluorescent proteins. Our multiple gene expression tool will be helpful to the advanced construction of genetically engineered yeast strains in a variety of research fields other than metabolic engineering.

Comparison of intubation performance between the King Vision and Macintosh laryngoscopes in novice personnel: a randomized, crossover manikin study.

PURPOSE: The King Vision laryngoscope is a newly developed video laryngoscope. We conducted a simulation study to evaluate the efficacy of the King Vision in novice personnel. METHODS: Thirty-one registered nurses with no previous experience with tracheal intubation were enrolled. Participants made 6 consecutive attempts at intubation of the manikin's trachea with a Macintosh laryngoscope (MAC) and the King Vision with channeled blade (KVC) and non-channeled blade (KVNC) in a randomized cross-over fashion. The Grading Scale of Intubation Difficulty (GSID) was rated on a 5-point scale. RESULTS: Overall median (range) intubation times (sec) were 16.9 (8.0-60.0) with the MAC, 20.5 (7.2-60.0) with the KVC, and 60.0 (11.0-60.0) with the KVNC. The KVNC required significantly longer intubation time compared with the MAC or the KVC (p < 0.001). Success rate with the KVNC was 47.3 %, which was significantly inferior to that with the MAC (91.4 %) or KVC (86.6 %). Median GSID was 2 (range 1-5) with the KVC and 3 (1-4) with the MAC, which were both significantly lower than the 4 (2-5) with the KVNC (p < 0.001). Esophageal intubation with the MAC occurred in 18 of 186 attempts, whereas no incidents of esophageal intubation occurred with the KVC or KVNC. CONCLUSION: The KVC facilitated intubation by novice personnel without incidence of esophageal intubation. However, intubation times, success rates, and GSID scores were similar to the values obtained with the MAC. These findings suggest that the KVC, but not the KVNC, could be used as an alternative device for intubation by novice personnel.

Azimuthal and radial variations in sap flux density and effects on stand-scale transpiration estimates in a Japanese cedar forest.

Understanding radial and azimuthal variation, and tree-to-tree variation, in sap flux density (Fd) as sources of uncertainty is important for estimating transpiration using sap flow techniques. In a Japanese cedar (Cryptomeria japonica D. Don.) forest, Fd was measured at several depths and aspects for 18 trees, using heat dissipation (Granier-type) sensors. We observed considerable azimuthal variation in Fd. The coefficient of variation (CV) calculated from Fd at a depth of 0-20 mm (Fd1) and Fd at a depth of 20-40 mm (Fd2) ranged from 6.7 to 37.6% (mean = 28.3%) and from 19.6 to 62.5% (mean = 34.6%) for the -azimuthal directions. Fd at the north aspect averaged for nine trees, for which azimuthal measurements were made, was -obviously smaller than Fd at the other three aspects (i.e., west, south and east) averaged for the nine trees. Fd1 averaged for the nine trees was significantly larger than Fd2 averaged for the nine trees. The error for stand-scale transpiration (E) estimates caused by ignoring the azimuthal variation was larger than that caused by ignoring the radial variation. The error caused by ignoring tree-to-tree variation was larger than that caused by ignoring both radial and azimuthal variations. Thus, tree-to-tree variation in Fd would be more important than both radial and azimuthal variations in Fd for E estimation. However, Fd for each tree should not be measured at a consistent aspect but should be measured at various aspects to make accurate E estimates and to avoid a risk of error caused by the relationship of Fd to aspect.

Explicit formulas for transmission characteristics of graded-index oval core fibers.

Transmission characteristics of graded-index oval (GIO) core fibers are theoretically analyzed, and basic equations representing the specific properties of the fiber are obtained. Formulas for the propagation constant, the field-profile function, the cutoff condition, and the total number of guided modes are derived in explicit forms. The formula for the change of the Gaussian beam radius as a function of the propagation distance is also given, and the numerical example agrees well with experimental data and agrees completely with that obtained by the beam-propagation method. These explicit expressions are useful for finding optimum structural parameters of GIO fibers to be used in practical fields.

Variable-field aspect-ratio transformer with cascaded graded-index oval-core fibers.

A new configuration is proposed for continuously transforming aspect ratios of field-intensity distributions in optical fibers. The field aspect ratio varies in proportion to the angle between the principal axes of two cascaded graded-index oval-core fibers. The highest aspect-ratio conversion is obtained at an angle of 90 degrees. The conversion effect is numerically and experimentally confirmed, showing that a circular field is successfully transformed into an elliptical one with an aspect ratio as high as 9 at a wavelength of 0.98 microm.

Intravenous alprostadil, an analog of prostaglandin E1, prevents thiamylal-fentanyl-induced bronchoconstriction in humans.

UNLABELLED: Prostaglandin (PG) E(1) relaxes airway smooth muscle in animals. However, no clinical data have been published on the bronchorelaxant effects of IV alprostadil, an analog of PGE(1). We have described experimental thiamylal-fentanyl-induced bronchoconstriction in humans; we now report the effect of IV alprostadil on thiamylal-fentanyl-induced bronchoconstriction. Thirty-two patients were allocated randomly to a control group (n = 16) and alprostadil group (n = 16). Anesthesia was induced with thiamylal 5 mg/kg and vecuronium 0.3 mg/kg and maintained with a continuous infusion of thiamylal 15 mg. kg(-1). h(-1). The lungs of the patients were ventilated with 50% nitrous oxide in oxygen. Twenty minutes after the induction of anesthesia, patients in the control group were given a continuous infusion of normal saline 20 mL/h, and those in the alprostadil group received a continuous infusion of alprostadil 0.2 micro g. kg(-1). min(-1) (20 mL/h), both for 60 min. Both groups were then given fentanyl 5 micro g/kg. Systolic and diastolic arterial blood pressure, heart rate, mean airway resistance (Rawm), expiratory airway resistance (Rawe), and dynamic lung compliance (Cdyn) were measured at the baseline, just before the fentanyl injection (T30), at three consecutive 6-min intervals after fentanyl injection (T36, T42, and T48), and 30 min after fentanyl injection (T60). Baseline Rawm, Rawe, and Cdyn values were comparable between groups. In the control group, both Rawm and Rawe were significantly increased at T36-60, and Cdyn was significantly decreased at T36-60 compared with the baseline. Patients given alprostadil showed no change in Rawm, Rawe, or Cdyn at T36-60. Thus, IV alprostadil seems to have a bronchodilator effect in humans. IMPLICATIONS: IV alprostadil, an analog of prostaglandin E(1), prevents thiamylal-fentanyl-induced bronchoconstriction in humans. This finding suggests that IV alprostadil has a bronchodilator effect.

Effect of prophylactic bronchodilator treatment with intravenous colforsin daropate, a water-soluble forskolin derivative, on airway resistance after tracheal intubation.

BACKGROUND: After induction of anesthesia, lung resistance increases. The authors hypothesized that prophylactic bronchodilator treatment with intravenous colforsin daropate, a water-soluble forskolin derivative, before tracheal intubation would result in decreased lung resistance and increased lung compliance after tracheal intubation when compared with placebo medication. METHODS: Forty-six adult patients were randomized to placebo or colforsin daropate treatment. Patients in the control group received normal saline; patients in the colforsin group received 0.75 microg. kg-1 x min-1 colforsin daropate intravenously until the study ended. Thirty minutes after the study began, the authors administered 5 mg/kg thiamylal and 5 microg/kg fentanyl for induction of general anesthesia and 0.3 mg/kg vecuronium for muscle relaxation. A 15-mg. kg-1. h-1 continuous infusion of thiamylal followed anesthetic induction. Four, 8, 12, and 16 min after tracheal intubation, mean airway resistance (R(awm)), expiratory airway resistance (R(awe)), and dynamic lung compliance (C(dyn)) were measured. RESULTS: Patients in the colforsin group had significantly lower R(awm) and R(awe) and higher C(dyn) after intubation than those in the control group. Differences in R(awm), R(awe), and C(dyn) between the two groups persisted through the final measurement at 16 min. At 4 min after intubation, smokers had a higher R(awm) and a lower C(dyn) than nonsmokers in the control group. After treatment by intravenous colforsin daropate, R(awm), R(awe), and C(dyn) values were similar for smokers and nonsmokers after tracheal intubation. CONCLUSIONS: Prophylactic treatment with colforsin daropate produced lower R(awm) and R(awe) and higher C(dyn) after tracheal intubation when compared with placebo medication. Pretreatment before intubation may be beneficial and advantageous for middle-aged smokers.

Intravenous nicorandil prevents thiamylal-fentanyl-induced bronchoconstriction in humans.

OBJECTIVE: Nicorandil has a hybrid property between nitrates and potassium channel openers and has been reported to cause a concentration-dependent relaxation of isolated guinea pig trachealis. Experimental asthma in a guinea pig model was also inhibited by nicorandil. However, no clinical data on the bronchorelaxant effects of this drug have been published. The aim of this study was to investigate whether intravenous nicorandil prevents thiamylal-fentanyl-induced bronchoconstriction. DESIGN: Double-blind, prospective, placebo-controlled, randomized study. PATIENTS: A total of 36 patients were randomly allocated to two groups: a control group (n = 18) and a nicorandil group (n = 18). INTERVENTIONS: Intravenous administration of nicorandil or a placebo (normal saline). MEASUREMENTS AND MAIN RESULTS: Anesthesia was induced with 5 mg/kg thiamylal and 0.3 mg/kg vecuronium. A continuous infusion of 15 mg x kg(-1) x hr(-1) thiamylal was then used to maintain the anesthesia. Controlled ventilation was maintained, delivering 50% nitrous oxide in oxygen. At 20 mins after the induction of anesthesia, the control group patients were given a 6 mL/hr continuous infusion of normal saline and the nicorandil group patients were given a 6 mg x hr(-1) (6 mL/hr) continuous infusion of nicorandil for 60 mins. At 30 mins after the start of the study, both groups received a 5-microg/kg dose of fentanyl. Systolic and diastolic arterial pressure, heart rate, mean airway resistance, expiratory airway resistance, and dynamic lung compliance were measured for the baseline condition, just before the administration of fentanyl (T30), at three consecutive 6-min intervals after the fentanyl injection (T36, T42, and T48) and 30 mins after the fentanyl injection (T60). Both groups had comparable baseline values for mean airway resistance, expiratory airway resistance, and dynamic lung compliance. In the control group, both mean airway resistance and expiratory airway resistance increased significantly at T36-60, compared with the baseline values, and dynamic lung compliance decreased significantly at T36-60, compared with the baseline value. In the nicorandil group, no changes in mean airway resistance, expiratory airway resistance, or dynamic lung compliance occurred at T36-60. CONCLUSIONS: Our observations suggest that the intravenous administration of nicorandil has a bronchodilator effect in humans.

Oral tizanidine, an alpha2-adrenoceptor agonist, reduces the minimum alveolar concentration of sevoflurane in human adults.

UNLABELLED: Tizanidine, an alpha2-adrenoceptor agonist, has an antinociceptive effect in animals. In humans premedicated with oral tizanidine, the increase in blood pressure associated with laryngoscopy and intubation was attenuated, and the amount of midazolam required for loss of consciousness was significantly reduced. We speculated that the oral administration of tizanidine might reduce the minimum alveolar anesthetic concentration (MAC) of sevoflurane. Fifty-two ASA physical status I-II patients, aged 24-56 yr, were randomly allocated into two groups: a Control group (n = 26) and a Tizanidine group (n = 26). As premedication, the Control group received a placebo, and the Tizanidine group received 4 mg of oral tizanidine 90 min before surgical skin incision. Anesthesia was induced in all patients by using vital capacity rapid inhaled induction with sevoflurane (5%). Loss of consciousness was defined as both the loss of the eyelid reflex and the lack of a response to a verbal command. MAC was determined by a technique adapted from the conventional up-down method for quantal responses. The MAC of sevoflurane was 2.2% +/- 0.2% in the Control group and 1.8% +/- 0.2% in the Tizanidine group (P = 0.0004). The time to loss of consciousness in the Tizanidine group (60.2 +/- 22.5 s) was significantly shorter than that in the Control group (73.7 +/- 26.3 s) (P = 0.03). The oral administration of tizanidine 4 mg successfully reduced the MAC of sevoflurane by 18% in human adults. IMPLICATIONS: Oral tizanidine (4 mg), an alpha2-adrenoceptor agonist, reduces the minimum alveolar concentration of sevoflurane by 18%.

Intravenous verapamil blunts hyperdynamic responses during electroconvulsive therapy without altering seizure activity.

IMPLICATIONS: A dose of 0.1 mg/kg of verapamil, administered immediately before anesthesia, significantly reduces the increase in peak heart rate and mean arterial blood pressure after electroconvulsive therapy. Furthermore, the administration of verapamil does not reduce the duration of the seizure.

Intravenous colforsin daropate, a water-soluble forskolin derivative, prevents thiamylal-fentanyl-induced bronchoconstriction in humans.

OBJECTIVE: Forskolin, a direct activator of adenylate cyclase, can relax airway smooth muscle, similar to other agents that increase intracellular cyclic adenine monophosphate. However, the potential usefulness of forskolin in treating bronchospasm is limited by its poor water solubility. Colforsin daropate is a novel and potent water-soluble forskolin derivative. No clinical data have been published on the bronchorelaxant effects of this drug. The aim of this study was to investigate whether intravenous colforsin daropate prevents thiamylal-fentanyl-induced bronchoconstriction. DESIGN: Double-blind, prospective, placebo-controlled randomized study. SETTING: University teaching hospital. PATIENTS: Thirty-six patients were allocated randomly to two groups: the control group (n = 18) and colforsin daropate group (n = 18). INTERVENTIONS: Intravenous administration of colforsin daropate or placebo (normal saline). MEASUREMENTS AND MAIN RESULTS: Anesthesia was induced with thiamylal 5 mg/kg and vecuronium 0.3 mg/kg. A 15 mg x kg(-1) x hr(-1) continuous infusion of thiamylal followed anesthetic induction. Controlled ventilation was maintained, delivering 50% nitrous oxide in oxygen. Twenty minutes after the induction of anesthesia, the control group patients started to receive 7.5 mL/hr continuous infusion of normal saline, and the colforsin daropate group patients started to receive 0.75 microg x kg(-1) x min(-1) (7.5 mL/hr) continuous infusion of colforsin daropate for 60 min. After that, both groups received fentanyl 5 microg/kg. Systolic and diastolic arterial pressure, heart rate, mean airway resistance (Rawm), expiratory airway resistance (Rawe), and dynamic lung compliance (Cdyn) were measured at the baseline, just before the administration of fentanyl (T30), at three consecutive 6-min intervals after fentanyl injection (T36, T42, and T48) and 30 min after fentanyl injection (T60). At baseline, both groups had comparable Rawm, Rawe, and Cdyn values. In the control group, Rawm increased significantly at T36-60 compared with the baseline, Rawe increased significantly at T36-48 compared with the baseline, and Cdyn decreased significantly at T36-60 compared with the baseline. In the colforsin daropate group, there were no changes in Rawm, Rawe or Cdyn at T36-60. CONCLUSIONS: These observations suggest that intravenous colforsin daropate has a bronchodilator effect in humans.

Blood patch therapy for spontaneous intracranial hypotension: safe performance after epidurography in an unconscious patient.

IMPLICATIONS: Epidurography was useful for identifying the epidural space and determining the likely spread of an epidural blood patch in an unconscious patient with spontaneous intracranial hypotension.