Area under the compound A concentration curve (compound A AUC) analysis.
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Anesthetics, Inhalation↗
Biomedical subjects
H Bito
Publications and source records attributed to H Bito.
[Cervical spine movement during orotracheal intubation using the McCoy laryngoscope compared with the Macintosh and the Miller laryngoscopes].
The movement of cervical spine during orotracheal intubation was compared using the McCoy, Macintosh or Miller laryngoscope blade. Twenty ASA 1-2 patients requiring tracheal intubation were studied. Following induction of anesthesia and obtaining muscle relaxation, the cross-table lateral X-ray was taken before and during laryngoscopy using three types of laryngoscopes. Degree of cervical spine movement was evaluated by measuring the distance between the spinous processes of C1 and the occiput, and the amount of displacement of C1 and C5 against C3 by tracing on each films. The results indicated that delta C1-occiput was larger and delta C1 + C5 smaller with the McCoy laryngoscope compared with the others. The use of the McCoy laryngoscope results in less cervical spine movement during laryngoscopy and therefore should be of particular benefit in the presence of cervical spine instability as well as in the normal patients.
Adolescent↗
[Perioperative management of a patient with severe anemia caused by rare Jr (a-) blood].
We experienced the anesthetic management of a patient with severe anemia as low as 1.8 g.dl-1 of hemoglobin and 6.5 per cent of hematocrit before surgery. His blood had been determined as type B, anti-Jra antibody positive and the proper blood was unavailable. We gave mainly colloid fluids and partially blood products of different blood groups to maintain the circulating volume with monitoring central venous pressure peri-operatively. The operation finished relatively uneventfully and the patient was transferred to the common ward from the intensive care unit on the fifth postoperative day. We conclude that maintaining the patient's circulating volume to avoid shock should be given priority in a case of severe anemia.
Aged↗
[Effects of toborinone on systemic circulation in patients under general anesthesia].
Patients with suppressed systemic circulation under general anesthesia received a 20-minute continuous infusion of toborinone at a rate of 5, 10, or 15 micrograms.kg-1.min-1, and the efficacy and safety of the drug were evaluated. Toborinone increased cardiac index (CI) and stroke volume index (SVI) dose-dependently, with significant increases at 10 and 15 micrograms.kg-1.min-1. An increase in CI was observed from 10 minutes after the start of infusion, with a return to the baseline value at 20-30 minutes after the completion of infusion. Toborinone did not affect heart rate at any dose tested, but the drug tended to decrease mean pulmonary arterial pressure, pulmonary capillary wedge pressure, and right atrial pressure. Mean arterial blood pressure tended to decrease after the start of infusion at all doses tested, and was significantly decreased at 20 minutes after the start of infusion at 10 and 15 micrograms.kg-1.min-1. Systemic vascular resistance and pulmonary vascular resistance decreased at all doses tested. T-wave amplitude on electrocardiaogram (ECG) and oxygen partial pressure in arterial blood decreased at 10 and 15 micrograms.kg-1.min-1. Toborinone increases cardiac output and decreases pre-load and after-load with no effects on heart rate, and, therefore, is thought to be a positive inotropic agent useful in the treatment of circulatory insufficiency. Due care should be exercised to monitor blood pressure, ECG, and arterial blood gas parameters of the patients. The effects of toborinone need to be further investigated in patients with complicated cardiac diseases under general anesthesia and in patients with circulatory insufficiency after surgery, including patients following extracorporeal circulation.
Adult↗
[Assessment of the practice of endotracheal intubation by levering Laryngoscope in teaching of undergraduate medical students].
Twenty-nine inexperienced medical students tried to intubate endotracheal tubes using both levering laryngoscope (McCoy laryngoscope) and Macintosh laryngoscope in adult mannikin the Cormack and Lehane Grade 2. The number of successful intubations by McCoy type was close to those by Macintosh type. Improvement in time necessary from insertion of the laryngoscope to confirmation of placement of the endotracheal tube McCoy type was also close to that by Macintosh type. But the grade of handling difficulty of McCoy type was significantly higher than that of Macintosh type, because Macintosh type was simpler to handle than McCoy type. It was suggested that Macintosh laryngoscope was more useful than McCoy laryngoscope for teaching of inexperienced medical students.
Adult↗
[Which laryngoscope is the most stressful in laryngoscopy; Macintosh, Miller, or McCoy?].
Stress responses during laryngoscopy were compared among the situations using three different laryngoscopes, Macintosh (curved standard blade), Miller (straight blade), or McCoy (levering). Blood pressure, heart rate (in 58 patients) and plasma concentration of catecholamines (in 29 patients) were measured before, during and after laryngoscopy without tracheal intubation. Systolic blood pressure after laryngoscopy was significantly higher in the Miller group than in other two groups. Plasma epinephrine concentrations after laryngoscopy in the McCoy group were lower than other two groups. Heart rate and plasma norepinephrine concentration were not different among the three groups. These results suggest that the stress response during laryngoscopy without intubation is the biggest in using the Miller laryngoscope and the smallest in using the McCoy laryngoscope.
Adolescent↗
CREB phosphorylation and dephosphorylation: a Ca(2+)- and stimulus duration-dependent switch for hippocampal gene expression.
While changes in gene expression are critical for many brain functions, including long-term memory, little is known about the cellular processes that mediate stimulus-transcription coupling at central synapses. In studying the signaling pathways by which synaptic inputs control the phosphorylation state of cyclic AMP-responsive element binding protein (CREB) and determine expression of CRE-regulated genes, we found two important Ca2+/calmodulin (CaM)-regulated mechanisms in hippocampal neurons: a CaM kinase cascade involving nuclear CaMKIV and a calcineurin-dependent regulation of nuclear protein phosphatase 1 activity. Prolongation of the synaptic input on the time scale of minutes, in part by an activity-induced inactivation of calcineurin, greatly extends the period over which phospho-CREB levels are elevated, thus affecting induction of downstream genes.
Calcineurin↗
Platelet-activating factor and somatostatin activate mitogen-activated protein kinase (MAP kinase) and arachidonate release.
Platelet-activating factor (PAF) receptor and somatostatin receptor (SSTR4) were cloned, and their primary structures were identified. They are both highly expressed in the rat hippocampus. When expressed in Chinese hamster ovary cells, these receptors activated mitogen-activated protein (MAP) kinase cascade and phospholipase A2. Arachidonic acid or its derivatives, thus produced by the activation of these receptors may play some roles in synaptic transmission and synaptic plasticity.
Animals↗
Signaling from synapse to nucleus: postsynaptic CREB phosphorylation during multiple forms of hippocampal synaptic plasticity.
Phosphorylation of the transcription factor CREB is thought to be important in processes underlying long-term memory. It is unclear whether CREB phosphorylation can carry information about the sign of changes in synaptic strength, whether CREB pathways are equally activated in neurons receiving or providing synaptic input, or how synapse-to-nucleus communication is mediated. We found that Ca(2+)-dependent nuclear CREB phosphorylation was rapidly evoked by synaptic stimuli including, but not limited to, those that induced potentiation and depression of synaptic strength. In striking contrast, high frequency action potential firing alone failed to trigger CREB phosphorylation. Activation of a submembranous Ca2+ sensor, just beneath sites of Ca2+ entry, appears critical for triggering nuclear CREB phosphorylation via calmodulin and a Ca2+/calmodulin-dependent protein kinase.
Action Potentials↗
Renal and hepatic function in surgical patients after low-flow sevoflurane or isoflurane anesthesia.
The safety of low-flow sevoflurane anesthesia, which produces higher concentrations of toxic compounds, has been questioned. One hundred surgical patients received sevoflurane or isoflurane anesthesia at a total flow rate of 1 L/min. End-tidal CO2 concentrations and inspired and end-tidal anesthetic concentrations were monitored during anesthesia. Pre- and postanesthetic clinical laboratory studies were performed in both groups, and no significant differences were found between groups. In the sevoflurane group, the concentrations of degradation products in the circuit were measured by gas chromatography and the temperature of the CO2 absorbent was also measured. Two degradation products were detected: CF2 = C(CF3-O-CH2F (Compound A) and CH3OCF2CH(CF3)OCH2F (Compound B). The highest measured mean concentration of Compound A was 24.6 +/- 7.2 (13.6-41.3) ppm, and that of Compound B (detected in 12 patients) was 1.5 ppm. In both groups, total bilirubin, direct bilirubin, aspartate aminotransferase, and alanine aminotransferase were increased postoperatively. There was no difference between groups. Low concentrations of Compound A were present in low-flow sevoflurane anesthesia, but no significant differences in clinical laboratory values were observed between low-flow sevoflurane and isoflurane anesthesia.
Adult↗
Synaptic plasticity: A molecular mechanism for metaplasticity.
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Animals↗
Amino-acid sequence and tissue distribution of guinea-pig leukotriene A4 hydrolase.
The guinea-pig leukotriene A4 hydrolase (LTA4H)-encoding cDNA was isolated from a guinea-pig lung cDNA library by cross-hybridization using a human probe. The deduced amino acid (aa) sequence consists of 611 aa (68 756 Da) and contains all twelve internal peptide and N-terminal sequences determined from the purified enzyme from guinea-pig intestine. The aa identity of the guinea-pig enzyme with its human, mouse and rat counterparts was 92.9, 90.5 and 90.4%, respectively. The previously characterized zinc-binding motif and a putative active site were highly conserved, supporting the aminopeptidase activity described for this enzyme. RNA blot analysis demonstrated ubiquitous expression of the LTA4H mRNA.
Amino Acid Sequence↗
Platelet-activating factor receptor.
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Amino Acid Sequence↗
Degradation products of sevoflurane during low-flow anaesthesia.
Low-flow (1 litre min-1) sevoflurane anaesthesia was used in 16 patients undergoing laparoscopic cholecystectomy (group LSC, n = 8) or tympanoplasty (group TP, n = 8), and concentrations of sevoflurane degradation products were measured. Degradation products in the circuit were measured hourly, and end-tidal carbon dioxide concentration, inspired and end-tidal sevoflurane concentrations, and carbon dioxide elimination were monitored. The only degradation product detected was CF2=C(CF3)-O-CH2F (compound A). The mean maximum concentrations of compound A were 21.6 (SEM 1.6) ppm and 19.6 (0.8) ppm in the LSC and TP groups, respectively (ns). The maximum temperatures of soda lime were 46.4 (0.5) degrees C and 44.8 (0.5) degrees C, respectively (P < 0.05). Hourly end-tidal sevoflurane concentrations and concentrations of sevoflurane degradation products were the same for both groups. Carbon dioxide elimination was the same for both groups 1 h after the start of anaesthesia, but was higher in group LSC after 2 h (P < 0.05). Intraperitoneal carbon dioxide insufflation associated with laparoscopic cholecystectomy had no effect on the concentration of sevoflurane degradation products.
Adult↗
Effect of total flow rate on the concentration of degradation products generated by reaction between sevoflurane and soda lime.
We have compared concentrations of degradation products in the circle system during sevoflurane anaesthesia at different fresh gas flows. Twenty-four patients underwent sevoflurane anaesthesia with fresh gas flows of 1 litre min-1 (1L group), 3 litre min-1 (3L group), or 6 litre min-1 (6L group) (n = 8 in each group). During anaesthesia, the concentrations of degradation products were measured every hour, and the temperature of soda lime, end-tidal carbon dioxide concentrations, inspired and end-tidal sevoflurane concentrations, and carbon dioxide elimination were measured. CF2 = C (CF3)-O-CH2F (compound A) was the only degradation product detected. The mean maximum concentration of compound A was 19.7 (SD 4.3) ppm in the 1L group, 8.1 (2.7) ppm in the 3L group and 2.1 (1.0) ppm in the 6L group (P < 0.05). The maximum temperature of soda lime was 44.6 (1.5) degrees C in the 1L group, 37.0 (4.4) degrees C in the 3L group and 29.1 (5.1) degrees C in the 6L group (P < 0.05). There were no significant differences in end-tidal sevoflurane concentration or mean carbon dioxide elimination between the groups. Only compound A was detected following anaesthesia, with higher concentrations observed at lower flow rates.
Adult↗
[Anesthetic management of a patient with microcephaly associated with cerebral atrophy].
We describe the management of a 35-year-old female with microcephaly, cerebral atrophy especially in frontal lobes, dwarfism and severe mental retardation. The patient underwent open reduction of fracture of the humerus neck suffered from traffic accident. Authors could not find any article on the anesthetic management of microcephaly but could locate some about mentally retarded patients claiming the difficulty in anesthetic induction as well as emergence and frequent incidence of convulsions. We anesthetized the patient with modified NLA with nitrous oxide-oxygen and interestingly very small doses of fentanyl (1.7 micrograms.kg-1) were required. The anesthetic and surgical courses were uneventful. The patient emerged immediately with intravenously administered naloxone and flumazenil with no excitement nor convulsion. We conclude that fentanyl is the drug of choice for mentally retarded patient with microcephaly and smaller doses per kg.weight are sufficient for orthopedic surgery.
Adult↗
On the mechanism of cytosolic phospholipase A2 activation in CHO cells carrying somatostatin receptor: wortmannin-sensitive pathway to activate mitogen-activated protein kinase.
We examined the mechanism of arachidonate release induced by somatostatin-14 (SS14) in CHO-K1 cells overexpressing rat hippocampal somatostatin receptor SSTR4. SSTR4 couples to pertussis toxin (PTX)-sensitive G-protein in CHO cells and does not lead to phosphoinositides breakdown or intracellular calcium ([Ca2+]i) mobilization (Bito et al.: J. Biol. Chem. 269, 12722-12730, 1994). SSTR4 activated mitogen-activated protein (MAP) kinase and induced the phosphorylation of 85kDa cytosolic phospholipase A2 (cPLA2), in a PTX-sensitive manner. Furthermore, activations of both MAP kinase and cPLA2 were inhibited by treatment with wortmannin, at almost identical IC50 values. Thus, SSTR4 appears to stimulate MAP kinase and cPLA2 in a Gi-dependent, and through a wortmannin-sensitive pathway. We also showed that stimulation with SS14, in combination with calcium-ionophore, strongly enhanced arachidonate release from these cells.
Androstadienes↗
Activation of mitogen-activated protein kinase and arachidonate release via two G protein-coupled receptors expressed in the rat hippocampus.
Platelet-activating factor and somatostatin receptors, two G protein-coupled receptors expressed in the rat hippocampus, were analyzed for the downstream signaling pathways in Chinese hamster ovary cells stably expressing each receptor. Ligand stimulation to each CHO cell line induced (1) inhibition of forskolin-induced accumulation of cAMP, (2) arachidonate release, and (3) activation of mitogen-activated protein kinase and MAP kinase kinase. In contrast, inositol phosphate breakdown was seen only in the PAF-stimulated CHO cells. The induction of these signals accompanied no detectable Ras activation. Suppression of the signals by pertussis toxin was almost complete for the somatostatin receptor but partial for the PAF receptor, suggesting that the somatostatin receptor couples only with PTX-sensitive G protein, while the PAF receptor couples with both PTX-sensitive and -insensitive G proteins. A model of G protein-mediated signaling pathways was proposed in which the signals from Gi and those from Gq converge at MAP kinase kinase and lead to arachidonate release. The present system using CHO cells is useful for analyzing signaling pathways from G proteins to MAP kinase kinase and will thereby provide clues for understanding the mechanisms underlying the physiological and pathological events mediated by PAF, somatostatin, and other G protein-coupled receptors in the central nervous system and other tissues.
Amino Acid Sequence↗