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Biomedical subjects

Kouichiro Minami

Publications and source records attributed to Kouichiro Minami.

At least 37 records · Page 2Linked to original sources
PubMed2004

[Management of sevoflurane anesthesia for a patient with multiple drug allergies].

There have been several reports on anesthesia for a patient with a history of multiple drug allergies. We present here anesthesia for a 33-year-old woman with histories of multiple drug allergies. She was scheduled to undergo total abdominal hysterectomy. We could not perform preoperative screening of the drugs using a dermal test because of a high risk of anaphylactic shock. Anesthesia was induced and maintained with sevoflurane and nitric oxide. The operation was finished without complications and her postoperative course was uneventful. It is important preoperatively to obtain histories of allergies adequately for recognition of allergens.

Adult↗
PubMed2004

[The airway management using laryngeal mask airway and tracheal fiberscopy in a pediatric patient with tracheal stenosis after tracheostomy].

A 9-year-old boy was scheduled for excision of tracheal granuloma which had developed at the tip of a tracheostomy tube. Instead of a tracheostomy tube, a 4 mm ID tracheal tube was inserted via the tracheostomy beyond the tracheal constriction because of rapid development of respiratory failure. General anesthesia was induced and maintained with sevoflurane and oxygen via the tube, and a size 2.5 laryngeal mask airway (LMA) was inserted without muscle relaxant. Spontaneous respiration remained. Under monitoring by fiberoptic tracheoscopy via the LMA, the tracheal tube was extubated carefully. An 8 Fr. suction tube was indwelled via the tracheostomy beyond the stenosis for oxygen supply. After sealing the tracheostomy, he could breath spontaneously through the LMA. During the excision of tracheal granuloma by holmium:YAG laser, fiberoptic observation was continued via the LMA, and the procedure was performed without any complication. We conclude that the tracheal stenosis can be managed using the LMA, continuous fiberoptic monitoring and additional option of keeping spontaneous ventilation.

Anesthesia, General↗
PubMed2004

[The management of extirpation of chronic expanding hematoma after thoracoplasty in the chest].

A 71-year-old man was scheduled for an extirpation of chronic expanding hematoma (CEH) of his right thorax. He had a history of right thoracoplasty for tuberculosis 37 years previously. He complained of dyspnea that had deteriorated over three months. His inflammatory responses including general fatigue and fever due to chronic empyema remained to be resolved. The chest computed tomography revealed that the CEH remarkably compressed the trachea and the heart resulting in the cause of left mediastinal deviation. General anesthesia was induced with fentanyl and propofol, and maintained with sevoflurane. During general anesthesia, mean central venous pressure (CVP) via the right femoral vein and arterial blood pressure (ABP) via the left radial artery were monitored. Bilateral peripheral vein catheters with 16 G could effectively provide huge amount of transfusion. Although his blood loss was 10,000 ml because of superior vena caval rupture and oozing from pleura, prompt and adequate management of hemodynamics could be maintained using CVP and ABP monitoring. The CEH is known as a specific type of chronic empyema and its extraction would require ingenuity since there are number of factors associated with diagnosis, indication and prevention. Each case is to be evaluated individually and managed carefully.

Aged↗
PubMed2003

Inhibition of the norepinephrine transporter function in cultured bovine adrenal medullary cells by bisphenol A.

We report here the effects of an environmental estrogen, bisphenol A, on norepinephrine (NE) transporter function in cultured bovine adrenal medullary cells. The effects of bisphenol A were compared to those of 17beta-estradiol. Bisphenol A significantly inhibited [3H]NE uptake by the cells in a concentration-dependent manner (1-100 microM). Kinetic analysis revealed that bisphenol A, as well as 17beta-estradiol, noncompetitively inhibited [3H]NE uptake. Bisphenol A and 17beta-estradiol inhibited the specific binding of [3H]desipramine to plasma membranes isolated from bovine adrenal medulla. As shown by Scatchard analysis of [3H]desipramine binding, bisphenol A increased the dissociation constant (K(d)) and decreased the maximal binding (B(max)), indicating a mixed type of inhibition. 17beta-Estradiol increased the K(d) without altering the B(max), thereby indicating competitive inhibition. The present findings suggest that bisphenol A inhibits the function of the NE transporter by acting on a site different from that of 17beta-estradiol in the adrenal medulla and probably in the brain noradrenergic neurons.

Adrenal Medulla↗
PubMed2003

Effects of the intravenously administered anaesthetics ketamine, propofol, and thiamylal on the cortical renal blood flow in rats.

Intravenous anaesthetics such as ketamine, propofol, and thiamylal are widely used, although the direct effects of these anaesthetics on the renal blood flow (RBF) have not been well elucidated. In this study, we examined the effects of bolus and continuous administrations of ketamine, propofol, and thiamylal on cortical RBF and the effects of noradrenaline (NA) on RBF under continuous administration of these anaesthetics. We used laser Doppler flowmetry to measure the effects of bolus injection and continuous infusion of ketamine, propofol, and thiamylal on cortical RBF in male Wistar rats. We also examined the effects of the anaesthetics on mean arterial blood pressure (MAP) and heart rate (HR). Bolus injections of ketamine, propofol, or thiamylal (1-8 mg/kg each, n = 10) at clinically relevant concentrations did not affect MAP, HR, or RBF. Continuous administration of ketamine, propofol, or thiamylal (1-8 mg/kg/h each, n = 10) did not affect MAP, HR or RBF. Exogenous NA (2 microg/kg) caused an increase in MAP and a decrease in RBF and HR. In experiments with continuous infusions of propofol or thiamylal (1-8 mg/kg/h each, n = 10), similar results were observed without infusion of any anaesthetics. However, bolus injection of NA did not result in a decrease in RBF during continuous ketamine infusion (98.8 +/- 6.7% of control, n = 6, p < 0.05), while ketamine did not affect the NA-induced increase in MAP. In conclusion, bolus and continuous administrations of ketamine, propofol, and thiamylal did not affect the RBF. From our present findings, ketamine would be useful for maintaining the RBF.

Anesthetics, Intravenous↗
PubMed2003

A forskolin derivative, colforsin daropate hydrochloride, inhibits rat mesangial cell mitogenesis via the cyclic AMP pathway.

A forskolin derivative, colforsin daropate hydrochloride (CDH), has been introduced as an inotropic agent that acts directly on adenylate cyclase to increase intracellular cyclic AMP (cAMP) levels and ventricular contractility, resulting in positive inotropic activity. We investigated the effects of CDH on rat mesangial cell (MC) proliferation. CDH (10(-7)-10(-5) mol/l) inhibited [(3)H]thymidine incorporation into cultured rat MCs in a concentration-dependent manner. CDH (10(-7)-10(-5) mol/l) also decreased cell numbers in a similar manner, and stimulated cAMP accumulation in MCs in a concentration-dependent manner. A protein kinase A inhibitor, H-89, abolished the inhibitory effects of CDH on MC mitogenesis. These findings suggest that CDH would inhibit the proliferation of rat MCs via the cAMP pathway.

Animals↗
PubMed2003

The preventive effects of mupirocin against nasotracheal intubation-related bacterial carriage.

UNLABELLED: Nasotracheal intubation is often required during dental and maxillofacial surgery. The complications of nasotracheal intubation are well documented, but there have been few systematic attempts to find methods for their prevention. We examined intubation-related carriage of bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), into the trachea and evaluated the effects of topical nasal treatment with mupirocin on intubation-related bacterial colonization. Of 38 patients without mupirocin treatment (nontreatment group), 27 (71.1%) showed general bacterial colonization in the nasal cavities before intubation. MRSA was isolated from 13.2% of the patients in this group. However, 10 of 22 patients (45%) treated with mupirocin (treatment group) showed colonization by general bacteria, and 2 (9%) were MRSA carriers before intubation. After nasal intubation, general bacteria and MRSA were isolated from the endotracheal tube tip in 66.2% and 16.7% of these patients in the nontreatment group, respectively. In contrast, general bacteria were isolated from the endotracheal tube tip in 19.2% of these patients after oral intubation, but no MRSA was detected. However, after nasal intubation, general bacteria were isolated from the endotracheal tube tip in 3 of the patients in the treatment group (23.1%), and no MRSA was detected, whereas no bacteria were isolated from oral intubation tubes. These results indicate that bacteria were carried into the trachea at a more frequent rate by nasal intubation as compared with oral intubation, and nasal treatment with mupirocin eliminated the nasal carriage of S. aureus. Topical nasal treatment with mupirocin before nasal intubation is thus suggested to be effective for preventing carriage of bacteria into the trachea. IMPLICATIONS: We studied the carriage rate of bacteria into the trachea caused by nasal intubation. The bacterial carriage by nasal intubation was more frequent than that by oral intubation, and intranasal administration of mupirocin eliminated the carriage of S. aureus. These results indicate that topical nasal treatment with mupirocin is effective to prevent carriage of bacteria into the trachea.

Administration, Intranasal↗
PubMed2003

The inhibitory effects of ketamine and pentobarbital on substance p receptors expressed in Xenopus oocytes.

UNLABELLED: Substance P receptors (SPR) modulate nociceptive transmission within the spinal cord. The effects of IV anesthetics on SPR are not clear. In this study, we investigated the effects of IV anesthetics on SPR expressed in Xenopus oocytes. We examined the effects of ketamine, pentobarbital, propofol, and tramadol on SP-induced Ca(2+)-activated Cl(-) currents mediated by SPR expressed in Xenopus oocytes using a whole-cell voltage clamp. Ketamine and pentobarbital inhibited the SPR-induced currents at pharmacologically relevant concentrations, but propofol and tramadol had little effect on the currents. We also studied the effects of ketamine and pentobarbital on [(3)H]-SP to SPR. Ketamine and pentobarbital inhibited the specific binding of [(3)H]-SP to SPR expressed in Xenopus oocytes. Scatchard analysis of [(3)H]-SP binding revealed that ketamine and pentobarbital decreased the apparent dissociation constant for binding and maximal binding, indicating noncompetitive inhibition. The protein kinase C (PKC) inhibitor bisindolylmaleimide I did not abolish the inhibitory effects of ketamine and pentobarbital on SP-induced Ca(2+)-activated Cl(-) currents. The results suggest that ketamine and pentobarbital inhibit SPR function. The mechanism of their inhibition on SPR function could not be through activation of the PKC pathway and may be due to noncompetitive displacing the SP binding. IMPLICATIONS: We investigated the effects of IV anesthetics on substance P receptors (SPR) expressed in Xenopus oocytes. Ketamine and pentobarbital inhibit SPR function via noncompetitive displacing SP binding. The findings imply that the inhibition of SPR function by these compounds may play a role in the analgesic effects of these IV anesthetics.

Aluminum Compounds↗
PubMed2003

Sino-atrial block during anesthesia in a patient with breast cancer being treated with the anticancer drug epirubicin.

IMPLICATIONS: Epirubicin, an anticancer drug, causes cardiotoxicity. We reported a case of sino-atrial block during general anesthesia in a woman with breast cancer who had received epirubicin. Anesthesiologists should be aware of the possible occurrence of sino-atrial block with epirubicin, and planting a pacemaker might be considered even in asymptomatic patients.

Anesthesia, General↗
PubMed2003

The inhibitory effects of alphaxalone on M1 and M3 muscarinic receptors expressed in Xenopus oocytes.

UNLABELLED: Alphaxalone is a neurosteroid anesthetic, but its mechanisms of action are not completely understood. Muscarinic receptors are involved in a variety of neuronal functions in the brain and autonomic nervous system, and much attention has been paid to them as targets of anesthetics. In this study, we investigated the effects of alphaxalone on M(1) and M(3) muscarinic receptors using the Xenopus oocyte expression system. Alphaxalone inhibited acetylcholine-induced currents in oocytes expressing M(1) receptors at clinically relevant concentrations. Alphaxalone also suppressed acetylcholine-induced currents in oocytes expressing M(3) receptors. The half-maximal inhibitory concentration values for the inhibition of M(1)- and M(3)-mediated currents were 1.8 +/- 0.6 micro M and 5.3 +/- 1.0 micro M, respectively. GF109203X, a selective protein kinase C inhibitor, had little effect on the inhibition of acetylcholine-induced currents by alphaxalone in oocytes expressing these receptors. Alphaxalone inhibited the specific binding of [(3)H]quinuclidinyl benzilate to oocytes expressing M(1) or M(3) receptors. These findings suggest that alphaxalone at clinically relevant concentrations inhibits the function of M(1) and M(3) receptors through a protein kinase C-independent mechanism by interfering with the [(3)H]quinuclidinyl benzilate binding sites on the receptors. IMPLICATIONS: Alphaxalone, a neurosteroid anesthetic, inhibited the function of muscarinic M(1) and M(3) receptors and the specific binding of [(3)H]quinuclidinyl benzilate ([(3)H]QNB) to oocytes expressing these receptors. These findings suggest that alphaxalone inhibits these receptors by interfering with the QNB binding sites.

Acetylcholine↗
PubMed2002

Up-regulation of noradrenaline transporter in response to prolonged exposure to ketamine.

We previously reported that the intravenous anaesthetic ketamine acutely inhibits the activity of the noradrenaline transporter (NAT) by acting on a site partly overlapping the desipramine binding site. Here we report the effects of a prolonged exposure to ketamine on the functional activity and number of NAT and its mRNA in cultured bovine adrenal medullary cells. Treatment of cells with ketamine (10-1000 microM) for 1-24 h resulted in a transient decrease and subsequent increase in [(3)H]noradrenaline (NA) uptake by the cells. Saturation analysis showed that ketamine (100 microM, 12 h) increased the V(max) value of [(3)H]NA uptake without any change in the K(m) value. Ketamine also increased the specific binding of [(3)H]nisoxetine to plasma membranes isolated from the cells. Scatchard analysis of [(3)H]nisoxetine binding revealed that ketamine increased the B(max) value without altering the K(d) value, suggesting an increase in the number of NAT in the plasma membrane. The stimulatory effect of ketamine on [(3)H]NA uptake was blocked by cycloheximide, an inhibitor of protein synthesis. Treatment of cells with ketamine for 12-24 h enhanced the expression of NAT mRNA. The present findings demonstrated that prolonged exposure to ketamine increases the functional activity of NAT and its mRNA. This may imply that ketamine negatively modulates sympathetic nervous activity through an up-regulation of NAT during long anaesthesia.

Adrenal Medulla↗
PubMed2002

Inhibitory effects of tramadol on nicotinic acetylcholine receptors in adrenal chromaffin cells and in Xenopus oocytes expressing alpha 7 receptors.

1. Tramadol has been used clinically as an analgesic; however, the mechanism of its analgesic effects is still unknown. 2. We used bovine adrenal chromaffin cells to investigate effects of tramadol on catecholamine secretion, nicotine-induced cytosolic Ca(2+) concentration ([Ca(2+)](i)) increases and membrane current changes. We also investigated effects of tramadol on alpha7 nicotinic acetylcholine receptors (AChRs) expressed in Xenopus oocytes. 3. Tramadol concentration-dependently suppressed carbachol-induced catecholamine secretion to 60% and 27% of the control at the concentration of 10 and 100 microM, respectively, whereas it had little effect on veratridine- or high K(+)-induced catecholamine secretion. 4. Tramadol also suppressed nicotine-induced ([Ca(2+)](i)) increases in a concentration-dependent manner. Tramadol inhibited nicotine-induced inward currents, and the inhibition was unaffected by the opioid receptor antagonist naloxone. 5. Tramadol inhibited nicotinic currents carried by alpha7 receptors expressed in Xenopus oocytes. 6. Tramadol inhibited both alpha-bungarotoxin-sensitive and -insensitive nicotinic currents in bovine adrenal chromaffin cells. 7. In conclusion, tramadol inhibits catecholamine secretion partly by inhibiting nicotinic AChR functions in a naloxone-insensitive manner and alpha7 receptors are one of those inhibited by tramadol.

Adrenal Medulla↗
PubMed2002

The inhibitory effects of anesthetics and ethanol on substance P receptors expressed in Xenopus oocytes.

UNLABELLED: The neuropeptide substance P (SP) modulates nociceptive transmission within the spinal cord. SP is unique to a subpopulation of C fibers found within primary afferent nerves. However, the effects of anesthetics on the SP receptor (SPR) are not clear. In this study, we investigated the effects of volatile anesthetics and ethanol on SPR expressed in Xenopus oocytes. We examined the effects of halothane, isoflurane, enflurane, diethyl ether, and ethanol on SP-induced currents mediated by SPR expressed in Xenopus oocytes, by using a whole-cell voltage clamp. All the volatile anesthetics tested, and ethanol, inhibited SPR-induced Ca(2+)-activated Cl(-) currents at pharmacologically relevant concentrations. The protein kinase C inhibitor bisindolylmaleimide I (bisindolylmaleimide) enhanced the SP-induced Cl(-) currents. However, bisindolylmaleimide abolished the inhibitory effects on SPR of the volatile anesthetics examined and of ethanol. These results demonstrate that halothane, isoflurane, enflurane, diethyl ether, and ethanol inhibit the function of SPR and suggest that activation of protein kinase C is involved in the mechanism of action of anesthetics and ethanol on the inhibitory effects of SPR. IMPLICATIONS: We examined the effects of halothane, isoflurane, enflurane, diethyl ether, and ethanol on substance P receptor (SPR) expressed in Xenopus oocytes, by using a whole-cell voltage clamp. All the anesthetics and ethanol inhibited SPR function, and the protein kinase C (PKC) inhibitor abolished these inhibitions. These results suggest that anesthetics and ethanol inhibit SPR function via PKC.

Anesthetics, Inhalation↗