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C Tashiro

Publications and source records attributed to C Tashiro.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of mass-labeled [13C14]-decabromodiphenylethane and its use as a surrogate standard in the analysis of sewage sludge samples.

Very little data is available about the presence of the brominated flame retardant, DBDPE, in the environment. This study reports the characterization of [(13)C(14)]-decabromodiphenylethane and the use of this surrogate standard to positively identify and quantify the presence of DBDPE in sewage sludge samples. The large difference in response factors between BDE-209 and DBDPE predicates the use of [(13)C(14)]-decabromodiphenylethane as a surrogate standard to improve the accuracy when determining the levels of DBDPE in environmental samples.

Bromobenzenes↗
PubMed2001

The effects of uterine and umbilical blood flows on the transfer of propofol across the human placenta during in vitro perfusion.

UNLABELLED: The safety of using propofol in parturients is controversial, and little information is available on the factors that influence the placental transfer of propofol. In this study, we investigated the effects of uterine and umbilical blood flows on the placental transfer of propofol by using the dually perfused human placental cotyledon. Placental transfer was evaluated on the basis of the placental clearances at various uterine and umbilical flow rates. The placental transfer of propofol was significantly facilitated by the increased uterine flow rates over the range from 7.5 to 25 mL/min. The placental clearances of propofol were also dependent on the umbilical flow rates over the range from 0.5 to 4.0 mL/min. In contrast, the placental transfer of antipyrine was flow dependent when the umbilical flow rate was <2.0 mL/min and became permeability limited when it was >2.0 mL/min. No differences in either maternal or fetal venous concentrations of propofol were observed as umbilical flow rates varied from 0.5 to 4.0 mL/min, suggesting that an equilibration across the placenta occurs at low flow rates. These results indicate that fetal uptake of propofol can be profoundly altered by the changes in both uterine and umbilical blood flows observed in various pathophysiologic conditions and that lipid solubility greatly influences placental transfer of drugs. IMPLICATIONS: Uterine and umbilical blood flows are determinant features in controlling the placental transfer of propofol, and, therefore, changes in these variables would significantly affect the extent of fetal exposure to propofol.

Adult↗
PubMed2001

[Introduction and clinical evaluation of a new non-invasive cardiac output monitor (NICO) based on Fick partial CO2 rebreathing method].

A newly developed non-invasive monitor, NICO (Novametrix Medical Systems Inc.), measures cardiac output based on changes in respiratory CO2 concentration caused by a brief period of rebreathing. By applying modified form of the CO2 Fick principle, cardiac output is calculated. We determined the accuracy and precision of this technique (RBCO) by comparing it with continuous thermodilution technique (TDCCO) and pulse dye densitometry technique (PDD). The overall difference between RBCO and TDCCO(n = 46) was -0.21 +/- 1.43 (bias +/- 2 SD)l.min-1. On the other hand, the overall difference between RBCO and PDD (n = 53) was -0.1 +/- 2.04 (bias +/- 2 SD)l.min-1. The degree of accuracy of RBCO was thought to be the same as those of TDCCO and PDD. We expect that NICO will be a useful cardiac output monitor in any method of general anesthesia in which PA catheterization is difficult or not indicated.

Anesthesia, General↗
PubMed2001

[Low dose intrathecal morphine and postoperative pain relief in elderly patients].

Patient (ASA PS I-III, mean age 68 +/- 14 yr) who had undergone lower extremity surgery under spinal anesthesia were studied to determine the effect of intrathecal administration of morphine 0.1 mg on intra- and postoperative pain relief and its side effects. They were randomly divided into control (C) and intrathecal morphine (M) groups (n = 25, respectively) and received 10 mg tetracaine in 4 ml of a quarter saline with 7.5 micrograms epinephrine. Incidence of intraoperative tourniquet pain was significantly lower in M group (36.8%) than in C group (64.3%). Postoperative pain was examined in terms of the duration until the first supplemental analgesic within 24 hr. The mean duration was 7.0 +/- 4.3 hr in the control group, but 11 patients in the M group needed it within 24 hr (18.1 +/- 6.8 hr, excluding 6 patients who did not receive analgesic). Although incidences of postoperative nausea, vomiting, and itching were higher in M group than in C group, none required antiemetic or naloxone. Both groups showed no difference in postoperative respiratory depression measured by apnea monitor (Eden Trace II, Mallinkrodt Japan, Tokyo). The results suggest that a low dose of intrathecal morphine is effective on postoperative 24 hr pain relief in elderly patients and that its side effects are negligible.

Aged↗
PubMed2001

[Evaluation of postoperative pain relief by infiltration of bupivacaine or epidural block after laparoscopic cholecystectomy].

We compared the analgesic effect of bupivacaine infiltration into surgical wounds with that of epidural block after laparoscopic cholecystectomy (LC). Forty-five patients (ASA physical status I-II) for LC were randomized into three groups (n = 15 in each group). Patients received only general anesthesia (Group C), received infiltration of 0.5% bupivacaine into the surgical wound before surgery combined with general anesthesia (Group L), or received epidural anesthesia combined with general anesthesia (Group E). Postoperative pain was assessed using visual analogue scale (scale: 0-10) at 1, 2, 6 and 12 hours after the operation, the need for additional supplemental analgesics, and the cost of anesthesia. Visual analogue scale in Group C at 1, 2, or 6 hours was significantly greater than that of Group L and E. The number of patients who needed supplemental analgesics was 9 in Group C, 5 in Group L, and 2 in Group E. The cost of pharmaceutical and anesthetic practice of Group E was more expensive than Group L and C. In conclusion, infiltration of bupivacaine combined with general anesthesia is an effective and economical method of postoperative pain relief.

Anesthesia, Epidural↗
PubMed2000

Effects of protein binding on the placental transfer of propofol in the human dually perfused cotyledon in vitro.

The placental transfer of propofol was investigated using the in vitro dually perfused cotyledon model of the human placenta, and the effects of protein binding in the foetal perfusate were examined. Both maternal and foetal circulations were perfused in a single-pass mode and > 30 min of stabilization was allowed before adding propofol and antipyrine to the maternal perfusate. The placental clearances of propofol were significantly increased by the augmented albumin concentrations in the foetal perfusate (1.68 (SD 0.68), 3.08 (1.55), 4.79 (1.76), 5.75 (1.89) and 7.03 (1.46) ml h-1 g-1 at the albumin concentrations of 4.4, 11, 22, 33 and 44 g litre-1, respectively). Although the total propofol concentration in the foetal vein increased significantly with increasing albumin concentration, the concentration of free propofol remained unchanged. These results indicate that binding to foetal albumin is a determining feature in the control of the placental transfer of propofol, and that the pharmacological effects of propofol on the foetus can be expected to be fairly constant and predictable from the maternal propofol concentration.

Albumins↗
PubMed2000

Pulmonary disposition of propofol in surgical patients.

BACKGROUND: The lungs have been mentioned as a possible site contributing to the extrahepatic clearance of propofol. The objective of the present study was to clarify the pulmonary disposition of propofol directly in human lungs by investigating both the first-pass uptake and pulmonary extraction at pseudo-steady state. METHODS: Nine patients were enrolled in the first-pass uptake study. Propofol (5 mg) and indocyanine green (ICG; 15 mg) were simultaneously administered via a central venous catheter within 1 s, and sequential arterial blood samples were obtained from the radial artery at 1-s intervals up to 45 s. Eleven patients were included in the infusion study, and propofol was infused via the jugular vein at a rate of 50 microgram. kg-1. min-1. Blood samples were simultaneously collected from pulmonary and radial arteries up to 60 min. RESULTS: A pronounced difference in the dilution curves between propofol and ICG was observed, and 28.4 +/- 11.6% (mean +/- SD) of propofol was taken up during the single passage through the human lung. The mean pulmonary transit time of propofol (31.3 +/- 6.0 s) was significantly longer than that of ICG (22.4 +/- 2.7 s; P < 0.01), indicating that some of the propofol trapped by lungs returned to the circulation by back diffusion. In the constant infusion study, no significant differences were observed with the plasma concentrations of propofol between pulmonary and radial arteries except for that at 2 min. The area under the curve of pulmonary and radial arterial concentration curves to 60 min were 59.1 +/- 14.8 and 56.8 +/- 12.5 microg. ml-1. min-1, respectively. No significant difference was observed with the area under the curve, suggesting that metabolism was not involved in the pulmonary uptake in human lungs. CONCLUSIONS: Most of the propofol that undergoes pulmonary uptake during the first pass was released back to the circulation by back diffusion. Metabolism was not involved in the pulmonary uptake in human lungs.

Anesthesia, General↗
PubMed2000

[Iatrogenic extrapleural hematoma].

We encountered a rare case of complications at the time of central venous catheterization due to extrapleural hematoma. A 71-year-old woman was scheduled to undergo subtotal gastrectomy. After introduction of general anesthesia, a CVP catheter was inserted from the right jugular vein, but it was removed intraoperatively, because of poor dropping of the infusion fluid. A few minutes later, the blood pressure started to decrease. We considered that this symptom was derived from the surgical procedure, and rapid blood transfusion associated with administration of a vasopressor was performed. Postoperative chest X ray revealed poorly delineated right lung field, and hemothorax was suspected. However thoracic drainage resulted in an extremely small amount of blood-like fluid. The abnormal defect in the right pulmonary field was found to be an extrapleural hematoma by thoracic CT on the first postoperative day. The hematoma was reduced by subsequent management in 7 days, and the patient was discharged from the ICU without any further complications.

Aged↗
PubMed2000

[Fluid management after off-pump CABG in a patient receiving preoperative continuous ambulatory peritoneal dialysis].

Perioperative management of off-pump CABG in a patient receiving continuous ambulatory peritoneal dialysis (CAPD) was reported. Prior to the procedure, we considered that postoperative management could be performed by CAPD alone in the case of off-pump CABG. However, due to an unexpected increase in the circulating blood volume and dilution of blood after surgery, congestive cardiac failure developed and active dehydration was required for 3 days after the operation using CHDF and HD. Despite this treatment, the central venous pressure and the cardiothoracic ratio in the chest X-ray were elevated, and a state of volume overload continued. However, cardiac contractility was not disturbed as shown by echocardiography. A possible cause of this condition was that body fluid had accumulated in the third space such as the peritoneum and intestine due to long-term use of CAPD before surgery, and the fluid was mobilized after surgery.

Aged↗
PubMed2000

[Recurrent abnormal motion of the lower legs during the recovery from spinal anesthesia].

A 33-yr-old pregnant woman developed recurrent motor-ataxia-like abnormal motion of the lower legs during the recovery from spinal anesthesia with hyperbaric tetracaine for repeated cesarean section. This symptom was thought to be due to the disturbance of coordination associated with the loss of positional sensation because deep sensory blockade seemed to be stronger and longer than motor blockade. The etiology of this abnormal motion could not be explained clearly, but her anatomical structure of the spine and her sensitivity to local anesthetic may have been related to this phenomenon.

Adult↗
PubMed1999

Improved oxygen delivery to the fetus during cesarean section under sevoflurane anesthesia with 100% oxygen.

PURPOSE: To assess the potential benefits of sevoflurane with 100% oxygen in cesarean section in terms of oxygen delivery to the fetus, neonatal depression, and uterine contractility. METHODS: Thirty-six patients undergoing elective cesarean section were enrolled. After thiamylal induction, 0.7% sevoflurane-60% nitrous oxide-40% oxygen anesthesia was administered in group G1 (n = 9), and 1.7% sevoflurane-100% oxygen anesthesia was administered in group G2 (n = 9). Spinal anesthesia under oxygen nasal prong was used in group SP (n = 18). RESULTS: At delivery, the PO(2) values in the maternal artery and the umbilical vein and artery (MA, UV, UA) of group G2 (474 +/- 50, 43 +/- 9, 32 +/- 9 mmHg, respectively) were significantly greater than those in groups G1 (228 +/- 46, 31 +/- 4, 23 +/- 5 mmHg, respectively) and SP (147 +/- 21, 30 +/- 7, 18 +/- 7 mmHg, respectively). The SO(2) in the UA of group G2 (56 +/- 17 %) was also greater than that in groups G1 (34 +/- 10 %) and SP (32 +/- 10 %). The sevoflurane concentrations at delivery in the MA, UV, and UA in group G2 were almost threefold higher than those in group G1, whereas all the newborns in the three groups had Apgar scores of 8 or more at 5 min, and the intraoperative blood loss did not differ among the groups. CONCLUSION: Sevoflurane anesthesia with 100% oxygen in elective cesarean delivery improves oxygen delivery to the fetus without severe neonatal depression, prolonged uterine relaxation, or increased blood loss.

Journal Article↗
PubMed1998

The effects of temperature and pressure on the thermodynamic activity of anesthetics.

Anesthetic potency is often expressed by volume percent or partial pressure in the gas phase, concentrations in the aqueous phase, etc. However. these values do not represent the anesthetic activity at the action sites. Because the activity at the action sites is difficult to obtain. Ferguson (Ferguson, J., 1939. Proc. R. Soc. Lond. B 127 387-404) defined the thermodynamic activity, which is the ratio between the anesthetizing partial pressure and the vapor pressure of the pure anesthetic at the same temperature. This paper discusses the effects of temperature and pressure on the thermodynamic activity of anesthetics. It also discusses the limitations of the Meyer-Overton rule.

Anesthetics↗
PubMed1998

Effects of halothane, ketamine and nitrous oxide on dynorphin mRNA expression in dorsal horn neurons after peripheral tissue injury.

Peripheral tissue injury is known to induce changes in gene expression in spinal neurons and result in a prolonged alteration of neuronal excitability. The purpose of this study was to examine the effect of halothane on the dynorphin mRNA expression in spinal dorsal horn neurons after peripheral tissue injury by formalin injection and compare the effect to that of ketamine and nitrous oxide. Male Sprague-Dawley rats were anesthetized with 1.3% halothane, ketamine, or 67% nitrous oxide. Fifteen minutes after induction of anesthesia, rats received an intraplantar injection of 150 microliter 5% formalin into the unilateral hindpaw. General anesthesia was maintained for 8 h, and the expression of preprodynorphin (PPD) and preproenkephalin (PPE) mRNAs in the spinal cord (L4-5) was examined by in situ hybridization. The degree of edema of the inflamed foot was not different among the three anesthesia groups and the control (no anesthesia) group. The number of neurons expressing PPD mRNA dramatically increased in the superficial dorsal horn ipsilateral to the formalin injection in the control group compared to the contralateral side. The number of neurons labeled for PPD mRNA in the halothane group was significantly less than the control group. However, the number of PPD mRNA-expressing neurons in both the ketamine and nitrous oxide groups was significantly less than the halothane group. The expression of PPE mRNA was not influenced by these anesthetics. These data indicate that the suppressive effect of halothane anesthesia on the induction of PPD mRNA in dorsal horn neurons was smaller than those of ketamine and nitrous oxide, suggesting an important supplemental way to control the alteration of gene expression in spinal neurons for clinical settings.

Anesthetics, General↗