Seong-Won Min

Effects of Ethanol on the rat Glutamate excitatory amino acid transporter type 3 expressed in Xenopus oocytes: Role of protein kinase C and phosphatidylinositol 3-kinase

BACKGROUND Glutamate is a major excitatory neurotransmitter in the central nervous system. Glutamate transporters play a critical role in maintaining extracellular glutamate concentrations. We investigated the effects of ethanol on a neuronal glutamate transporter, excitatory amino acid transporter type 3 (EAAT3), and the role of protein kinase C (PKC) and phosphatidylinositol 3-kinase (PI3 K) in mediating these effects. METHODS EAAT3 was expressed in Xenopus oocytes by injection of EAAT3 messenger RNA. By using a two-electrode voltage clamp, membrane currents were recorded after the application of l-glutamate. Responses were quantified by integration of the current trace and reported as microcoulombs. Data are mean +/- SEM. RESULTS Ethanol enhanced EAAT3 activity in a concentration-dependent manner. At 25, 50, 100, and 200 mM of ethanol, the responses were significantly increased compared with control values. Kinetic study demonstrated that ethanol (50 mM) significantly increased Vmax (3.48 +/- 0.2 microC for control versus 4.16 +/- 0.24 microC for ethanol; n = 19; p < 0.05) without a significant change in the Km (65.6 +/- 11.1 microM for control versus 55.8 +/- 9.6 microM for ethanol; n = 19; p > 0.05) of EAAT3 for glutamate. Preincubation of the oocytes with phorbol-12-myristate-13-acetate (PMA) significantly increased EAAT3 activity (0.98 +/- 0.08 muC for control versus 1.28 +/- 0.09 microC for ethanol; n = 19; p < 0.05). However, there was no statistical difference among the responses of EAAT3 to PMA, ethanol, or PMA plus ethanol. Although the PKC inhibitors chelerythrine and staurosporine did not decrease the basal EAAT3 activity, they abolished the enhancement of EAAT3 activity by ethanol. Pretreatment with wortmannin, a PI3 K inhibitor, also abolished the ethanol-enhanced EAAT3 activity. CONCLUSIONS These results suggest that acute ethanol exposure increases EAAT3 activity at clinically relevant concentrations and that PKC and PI3 K may be involved in mediating these ethanol effects.

Power spectral analysis of heart rate variability during acute hypoxia in fetal lambs

Backgrounds.  The aim of the current study was to investigate the changes in the power spectral pattern of the heart rate variability of fetal lambs during acute hypoxia and the possible value of power spectral analysis as a quantitative fetal monitoring method.

Axillary approach versus the infraclavicular approach in ultrasound-guided brachial plexus block: comparison of anesthetic time.

Background With ultrasound guidance, the success rate of brachial plexus block (BPB) is 95-100% and the anesthetic time has become a more important factor than before. Many investigators have compared ultrasound guidance with the nerve stimulation technique, but there are few studies comparing different approaches via the same ultrasound guidance. We compared the axillary BPB with the infraclavicular BPB under ultrasound guidance. Methods Twenty-two ASA physical status I-II patients presenting with elective forearm surgery were prospectively randomized to receive an axillary BPB (group AX) or an infraclavicular BPB (group IC) with ultrasound guidance. Both groups received a total of 20 ml of 1.5% lidocaine with 5 µg/ml epinephrine and 0.1 mEq/ml sodium bicarbonate. Patients were then evaluated for block onset and block performance time was also recorded. Results Group IC demonstrated a reduction in performance time vs. group AX (622 ± 139 sec vs. 789 ± 131 sec, P < 0.05). But, the onset time was longer in group IC than in group AX (7.7 ± 8.8 min vs. 1.4 ± 2.3 min, P < 0.05). All blocks were successful in both groups. Conclusions Under ultrasound guidance, infraclavicular BPB was faster to perform than the axillary approach. But the block onset was slower with the infraclavicular approach.

Intravenous patient-controlled analgesia to manage the postoperative pain in patients undergoing craniotomy

Background This randomized controlled study evaluated the efficacy of intravenous patient-controlled analgesia (IV-PCA) with fentanyl and ketorolac for neurosurgical patients, and compared the effectiveness of IV-PCA with intermittent analgesics injection. Methods The patients undergoing craniotomy were randomly assigned to two groups. Patients of group P (n = 53) received fentanyl (0.2 µg/kg/hr) and ketorolac (0.3 mg/kg/hr) via IV-PCA, and those of group N (n = 53) received intermittent fentanyl or ketorolac injection as needed. Pain was evaluated using a 0-10 visual analogue scale (VAS) at postoperative 1, 4, and 24 hr. The amount of infused analgesic drugs, Glasgow Coma Scale (GCS) score, systolic arterial pressure, heart rate, respiratory rate, and the incidence of nausea and miosis were measured at the same time points. Results Although VAS of pain (VASp) was comparable at postoperative 1 hr (P = 0.168) between the two groups, the group P had significantly lower VASp at postoperative 4 hr (P = 0.007) and 24 hr (P = 0.017). In group P, less analgesic drugs were administered at postoperative 1 hr, and more analgesic drugs were administered at postoperative 24 hr. There were no differences between two groups with respect to nausea, GCS, systolic arterial pressure, and heart rate. IV-PCA did not further incur respiratory depression or miosis. Conclusions IV-PCA with fentanyl and ketorolac after craniotomy is more effective analgesic technique, without adverse events, than the intermittent administration of analgesics.

A short period of inhalation induction with sevoflurane prevents rocuronium-induced withdrawal in children

Background: The aim of this study was to determine whether or not inhalation induction with sevoflurane can prevent the withdrawal movement associated with the injection of rocuronium.

The use of a nasogastric tube to facilitate nasotracheal intubation: a randomised controlled trial

During nasotracheal intubation, the tracheal tube passes through either the upper or lower pathway in the nasal cavity, and it has been reported to be safer that the tracheal tube passes though the lower pathway, just below the inferior turbinate. We evaluated the use of a nasogastric tube as a guide to facilitate tracheal tube passage through the lower pathway, compared with the ‘conventional’ technique (blind insertion of the tracheal tube into the nasal cavity). A total of 60 adult patients undergoing oral and maxillofacial surgery were included in the study. In 20 out of 30 patients (66.7%) with the nasogastric tube‐guided technique, the tracheal tube passed through the lower pathway, compared with 8 out of 30 patients (26.7%) with the ‘conventional’ technique (p = 0.004). Use of the nasogastric tube‐guided technique reduced the incidence and severity of epistaxis (p = 0.027), improved navigability (p = 0.034) and required fewer manipulations (p = 0.001) than the ‘conventional’ technique.

Effects of sevoflurane on neuronal cell damage after severe cerebral ischemia in rats

Background The aim of this study was to investigate the neuroprotective effects of sevoflurane after severe forebrain ischemic injury. We also examined the relationship between the duration of ischemia and neuronal cell death. Methods Male Sprague-Dawley rats (300-380 g) were subjected to 6 (each n = 6) or 10 min (each n = 10) of near-complete forebrain ischemia while anesthetized with either 50 mg/kg of zoletil given intraperitoneally or inhaled sevoflurane (2.3%). Ischemia was induced by bilateral common carotid artery occlusion plus hemorrhagic hypotension (26-30 mmHg). Histologic outcomes were measured 7 days after ischemia in CA1 pyramidal cells of the rat hippocampus. Results The mean percentage of necrotic cells in the hippocampal CA1 area decreased in the sevoflurane group compared to the zoletil group (25% vs. 40% after 6 min ischemia, respectively: P = 0.004 and 44% vs. 54% after 10 min of ischemia, respectively P = 0.03). The percentage of apoptotic cells was similar in all groups. The percentage of necrotic cells in each anesthetic groups was significantly higher in the 10 min ischemia group compared to the 6 min ischemia group (P = 0.004 in the sevoflurane group, P = 0.03 in the zoletil group). Conclusions The present data show that sevoflurane has neuroprotective effects in rats subjected to near-complete cerebral ischemia. Longer duration of ischemia is associated with more neuronal injury when compared to ischemia of shorter duration.

Propofol–ketamine or propofol–remifentanil for deep sedation and analgesia in pediatric patients undergoing burn dressing changes: a randomized clinical trial

In this study, we compared the propofol–ketamine and propofol–remifentanil combinations for deep sedation and analgesia during pediatric burn wound dressing changes.

Effect of coenzyme Q10 on spinal cord ischemia-reperfusion injury

OBJECT Spinal cord ischemia remains a serious complication of thoracoabdominal aortic aneurysm surgery. Coenzyme Q10, a potent antioxidant, has been reported to exert a neuroprotective effect. In the present study, we evaluated the effect of coenzyme Q10 pretreatment on spinal cord ischemia-reperfusion injury. METHODS Male Sprague-Dawley rats were treated with either 300 mg/kg coenzyme Q10 (CoQ10 group, n = 12) or saline (control and sham groups, n = 12 for each group) for 5 days before ischemia. Spinal cord ischemia was induced in the control and CoQ10 groups. Neurological function was assessed using the Basso-Beattie-Bresnahan (BBB) motor rating scale until 7 days after reperfusion, and then the spinal cord was harvested for histopathological examinations and an evaluation of malondialdehyde level. RESULTS On post-reperfusion Day 1, the CoQ10 group showed higher BBB scores compared with those in the control group, although the difference was not significant. However, on Day 2, the CoQ10 group showed a significantly higher BBB score than the control group (14.0 [10.3-15.0] vs 8.0 [5.0-9.8], median [IQR], respectively; p = 0.021), and this trend was maintained until Day 7 (17.5 [16.0-18.0] vs 9.0 [6.5-12.8], respectively; p < 0.001). Compared with the control group, the CoQ10 group had more normal motor neurons (p = 0.003), fewer apoptotic changes (p = 0.003) and a lower level of tissue malondialdehyde (p = 0.024). CONCLUSIONS Pretreatment with 300 mg/kg coenzyme Q10 resulted in significantly improved neurological function and preservation of more normal motor neurons.

Effect of prophylactic benzydamine hydrochloride on postoperative sore throat and hoarseness after tracheal intubation using a double-lumen endobronchial tube: a randomized controlled trial

PurposeWe evaluated the prophylactic effect of benzydamine hydrochloride (BH) spray on postoperative sore throat and hoarseness secondary to intubation with a double-lumen endobronchial tube (DLT).MethodsNinety-two adult patients undergoing thoracic surgery using DLT intubation were studied. The DLT cuff and oropharyngeal cavity were sprayed with normal saline (Group S; n = 46) or BH (Group BH; n = 46) prior to intubation. Postoperative sore throat and hoarseness were evaluated at one, six, and 24 hr after surgery. Sore throat was evaluated using a 0-100 mm visual analogue scale (VAS). Hoarseness was defined as a change in voice quality.ResultsCompared with Group S, postoperative sore throat occurred less frequently in Group BH at one hour (mean difference, 28.3%; 95% confidence interval [CI], 8.7 to 45.1; P = 0.01), at six hours (mean difference, 32.6%; 95% CI, 12.6 to 49.2; P < 0.01), and at 24 hr (mean difference, 28.3%; 95% CI, 9.3 to 44.7; P = 0.01) after surgery. Group BH had lower VAS scores for postoperative sore throat at one hour (mean difference, 12.8; 95% CI, 4.9 to 20.7), at six hours (mean difference, 11.9; 95% CI, 4.8 to 19.1; P < 0.01), and at 24 hr (mean difference, 5.3; 95% CI, 0.9 to 9.7; P = 0.01) after surgery. Hoarseness also occurred less frequently in Group BH at one hour (mean difference, 23.9%; 95% CI, 6.8 to 39.6; P = 0.01), at six hours (mean difference, 23.9%; 95% CI, 7.4 to 39.3; P = 0.01), and at 24 hr (mean difference, 21.7%; 95% CI, 5.5 to 37.0; P = 0.02) after surgery (P < 0.01).ConclusionsProphylactic application of BH to the DLT cuff and oropharyngeal cavity reduces the incidence and severity of postoperative sore throat and the incidence of hoarseness associated with DLT intubation. The trial was registered at the Clinical Research Information Service (KCT0001068).RésuméObjectifNous avons évalué l’effet prophylactique d’un vaporisateur de chlorhydrate de benzydamine (CB) sur les maux de gorge et l’enrouement postopératoires découlant d’une intubation réalisée avec une sonde endobronchique à double lumière (SDL).MéthodeQuatre-vingt-douze patients adultes subissant une chirurgie thoracique et intubés avec une SDL ont pris part à l’étude. Le ballonnet de la SDL et la cavité oropharyngée ont été vaporisés avec du sérum physiologique (groupe S; n = 46) ou du CB (groupe CB; n = 46) avant l’intubation. Les maux de gorge et l’enrouement postopératoires ont été évalués à une, six et 24 heures après la chirurgie. Les maux de gorge ont été évalués à l’aide d’une échelle visuelle analogique (EVA) de 0-100 mm. L’enrouement a été défini comme un changement de la qualité vocale.RésultatsPar rapport au groupe S, les maux de gorge postopératoires étaient moins fréquents dans le groupe CB une heure (différence moyenne, 28,3 %; intervalle de confiance [IC] 95 %, 8,7 à 45,1; P = 0,01), six heures (différence moyenne, 32,6 %; IC 95 %, 12,6 à 49,2; P < 0,01) et 24 heures (différence moyenne, 28,3 %; IC 95 %, 9,3 à 44,7; P = 0,01) après la chirurgie. Les scores du groupe CB sur l’EVA étaient plus bas en matière de maux de gorge postopératoires une heure (différence moyenne, 12,8; IC 95 %, 4,9 à 20,7), six heures (différence moyenne, 11,9; IC 95 %, 4,8 à 19,1; P < 0,01) et 24 heures (différence moyenne, 5,3; IC 95 %, 0,9 à 9,7; P = 0,01) après la chirurgie. L’enrouement était également moins fréquent dans le groupe CB une heure (différence moyenne, 23,9 %; IC 95 %, 6,8 à 39,6; P = 0,01), six heures (différence moyenne, 23,9 %; IC 95 %, 7,4 à 39,3; P < 0,01) et 24 heures (différence moyenne, 21,7 %; IC 95 %, 5,5 à 37,0; P = 0,02) après la chirurgie (P < 0,01).ConclusionL’application prophylactique de CB au ballonnet de la SDL et à la cavité oropharyngée réduit l’incidence et la gravité des maux de gorge postopératoires et l’incidence d’enrouement associées à l’intubation via SDL. Cette étude a été enregistrée au Clinical Research Information Service (KCT0001068).