Interleukin-5 Antagonist Monoclonal Antibody Therapy Improves Symptoms and Reduces Steroid Dependence in Eosinophilic Myocarditis Patients

Eosinophilic myocarditis (EM) is a rare disease associated with significant morbidity and mortality. This case series follows the clinical courses of 3 patients with EM. The use of mepolizumab, an anti-interleukin-5 monoclonal antibody, as an adjunctive treatment was associated with stabilization of cardiac function and improved long-term outcomes.

Reversible cardiomyopathy in a patient with chronic myelomonocytic leukemia treated with decitabine/cedazuridine: a case report

BACKGROUND

Hypomethylating agents (HMAs) have shown efficacy in the treatment of hematological malignancies and are indicated for the treatment of chronic myelomonocytic leukemia (CMML). While the HMA decitabine, in its intravenous formulation, has been used since 2006 for the treatment of CMML, use of its oral formulation has been limited by poor bioavailability due to first-pass metabolism by the enzyme cytidine deaminase. The dose of intravenous decitabine is limited by toxicities such as cardiomyopathy and heart failure. Therefore, cedazuridine was developed as an inhibitor of cytidine deaminase. Cedazuridine decreases the first-pass metabolism of oral decitabine allowing therapeutic levels to be achieved at lower doses, and thus, the novel oral combination of cedazuridine with decitabine was developed. While cardiomyopathy and heart failure are well-established adverse effects associated with intravenous decitabine alone, there to our knowledge there have been no documented incidences of reversible cardiomyopathy in the literature or in patients who participated in the phase 2 and phase 3 clinical trials of oral decitabine-cedazuridine.

CASE

This case study presents an 85 year-old Caucasian female with CMML who developed cardiomyopathy and heart failure with reduced ejection fraction after completing 5 cycles of therapy with decitabine/cedazuridine. Furthermore, her symptoms and cardiac function recovered upon discontinuation of the drug.

CONCLUSIONS

We present an occurrence of reversible cardiomyopathy in a patient who completed 5 cycles of decitabine/cedazuridine, an oral combination therapy developed to enhance oral bioavailability of decitabine thereby limiting its adverse effects. As the decitabine/cedazuridine combination therapy rises in popularity due to its convenient oral formulation, more trials are needed to understand the prevalence of cardiomyopathy with this drug and to discover preventative strategies for cardiotoxic effects.

A comparative study of transradial versus transfemoral approach for flow diversion

PURPOSE

Data in neurointerventional literature is extremely limited regarding the safety and efficacy of flow diversion using transradial access (TRA). We aim to demonstrate the safety and efficacy of intracranial aneurysm treatment with the Pipeline Embolization Device (PED) using TRA compared to transfemoral access (TFA).

METHODS

We conducted a retrospective analysis of a prospectively maintained database and identified 79 consecutive patients who underwent neuroendovascular embolization for cerebral aneurysms using the PED from April 2018 through October 2019. Patients were divided into 2 groups: TRA (32 patients) and TFA (47 patients). A comparative analysis was performed between the two groups.

RESULTS

There was no significant difference in postoperative intracranial hemorrhage (p>.99), symptomatic ischemic stroke (p=.512), access site complications (p=.268), or other complications (p=.512). However, there was a significant increase in overall complications (14.9% vs. 0.0%, p=.038) and procedure duration (71.4 min ± 31.2 vs. 58.5 ± 20.3, p=.018) in the TFA group. There was no significant difference in complete occlusion at latest follow-up (19/25, 76.0% vs. 35/40, 87.5%; p=.311), 6-month follow-up (17/23, 73.9% vs. 33/38, 86.8%; p=.303), or 12-month follow-up (8/8, 100.0% vs. 5/6, 83.3%; p=.429). There was also no significant difference in rate of retreatment (p>.99), morbidity (p=.512), mortality (p>.99), latest follow-up (p=.985), or loss of follow-up (p=.298).

CONCLUSIONS

The feasibility and efficacy of flow diversion with the PED via TRA for the treatment of intracranial aneurysms is comparable to TFA. Widespread adoption of this approach may be facilitated by improvements in device navigation and manipulation via radial-specific engineering.

Endovascular Management of Complex Fenestration-Associated Aneurysms: A Single-Institution Retrospective Study and Review of Existing Techniques

BACKGROUND

Aneurysms associated with fenestrations of intracranial arteries are exceptionally rare findings. Management strategies for these aneurysms are not well-defined, especially regarding endovascular treatment. We sought to investigate the strategies and feasibility of endovascular treatment approaches for various fenestration-associated intracranial aneurysms.

METHODS

We performed a retrospective chart review of 2000 aneurysms treated endovascularly, identifying 8 aneurysms located at arterial fenestrations. The technical details and procedural outcomes were reviewed to identify common management approaches, technical nuances, and treatment outcomes.

RESULTS

There were 3 (37.5%) aneurysms associated with fenestrations of the basilar artery or vertebrobasilar junction. All 3 were successfully treated with a previously undescribed coil-assisted flow-diversion technique, resulting in complete obliteration. Three (37.5%) aneurysms were associated with fenestrations of the anterior communicating artery. Of those, 2 were successfully treated with stent-assisted coil embolization and 1 with coil embolization alone. One (12.5%) aneurysm was associated with a fenestration of the paraclinoid internal carotid artery and 1 (12.5%) aneurysm found was at the takeoff of the posterior inferior cerebellar artery at a fenestration of the vertebral artery. Both were successfully treated with coil-assisted flow diversion. There were no permanent procedural complications. Major considerations for endovascular management of these aneurysms were the dominance of fenestration trunks, aneurysms arising from the fenestration apex or a fenestration limb, amenability to flow diversion, and anticipation of vascular remodeling.

CONCLUSIONS

Fenestration-associated aneurysms are very rare. We have identified common factors to help guide decision-making for endovascular approaches and demonstrate successful aneurysm treatment using these methods.

Posterior circulation tandem occlusions: Classification and techniques

BACKGROUND

Posterior circulation tandem occlusions are poorly characterized in current literature. Data regarding endovascular approaches and outcomes in this patient subgroup is extremely limited.

METHODS

We conducted a retrospective analysis of a prospectively maintained database and identified 17 patients with posterior circulation tandem occlusions who underwent mechanical thrombectomy between 2014 and 2019.

RESULTS

Of 17 patients with posterior circulation tandem occlusion, the mean age was 55.76 ± 11.8 with 35.3% female. The mean NIHSS score on presentation was 17.2 ± 9.2. Tissue plasminogen activator was administered in 7 (41.2%) patients, stent-retrievers alone were used in 2 (11.8%), aspiration catheters alone were used in 2 (11.8%), a combination was used 12 (70.6%), and a self-expandable stent in 5 (29.4%). The mean number of device passes was 2.24 ± 2.02, recanalization failure occurred in 4 (23.5%) patients, the mean time from stroke onset to puncture was 6.9 ± 2.4 h, and the mean time from puncture to recanalization was 59.3 ± 26.6 min. Postprocedural symptomatic ICH occurred in 1 (5.9 %) patient, periprocedural ICH/SAH occurred in 2 (11.8%), periprocedural distal emboli occurred in 0 (0%), periprocedural vessel dissection occurred in 1 (5.9%), and periprocedural vessel perforation occurred in 1 (5.9%) patient. TICI score>2b was achieved in 13 (76.5%) patients. An improvement in NIHSS>3 at discharge occurred in 10 (58.8%) patients, and good outcomes (mRS score < 2) occurred in 7 (41.2%). The mean length of stay was 11.6 ± 12.2 days, and the mortality rate was 41.2%.

CONCLUSION

Endovascular intervention with mechanical thrombectomy is safe and feasible in patients with posterior circulation tandem occlusions.

Access Through the Anatomical Snuffbox for Neuroendovascular Procedures: A Single Institution Series

BACKGROUND

Distal transradial catheterization in the anatomic snuffbox is an alternate route of access that has started to gain consideration for neuroendovascular procedures.

OBJECTIVE

To assess the feasibility and outcomes and present our institution's experience in performing neuroendovascular procedures via distal transradial access (dTRA).

METHODS

We conducted a retrospective analysis and identified 120 patients who underwent consecutive neuroendovascular procedures via dTRA in the anatomic snuffbox. Data collection was performed on indication for procedure, sheath size, number of vessels selectively catheterized, fluoroscopy time, procedure duration, radiation exposure, conversion to femoral approach, access site complication, and procedure success.

RESULTS

Of 120 patients with an average age of 54.7 yr ± 14.7, 73 (60.8%) underwent diagnostic angiograms, 38 (31.7%) underwent follow-up angiograms, and 9 (7.5%) underwent therapeutic procedures. The overall mean number of vessels catheterized was 2.5 ± 0.1 per procedure, the mean procedure time was 68.3 min ± 43.4, the mean fluoroscopy time was 10.8 min ± 7.6, the mean contrast dose was 70.6 mL ± 39.1, and the mean radiation exposure was 27 672.2 mGycm2 ± 42 728.4. Successfully completed therapeutic procedures included aneurysm 1 (0.8%), arteriovenous malformation (AVM)/arteriovenous fistula/carotid cavernous fistula 7 (5.8%), and 1 (0.8%) other treatment. Three patients (2.5%) required adjunct transfemoral endovenous access for AVM embolization. Two minor complications (1.67%) were a local wrist hematoma and a radial artery vasospasm without any sequelae.

CONCLUSION

Distal radial artery catheterization in the anatomic snuffbox is a safe and effective access site to perform neuroendovascular procedures. Complications and conversion rate are low making it a safe alternative.

Coil Embolization of Wide-Neck Bifurcation Aneurysms via Shouldering and Framing: A Safe Alternative to Conventional Techniques

OBJECTIVE

Double stent-assisted coiling of wide-neck bifurcation aneurysms (WNBAs) can be technically challenging with high thromboembolic rates. Single stent-assisted coiling (SSAC) decreases procedural complexity and thromboembolic risk but increases risk of coil prolapse and recanalization. In this study, we present our institution's experience with SSAC of WNBA performed via a "shouldering" and "framing" with a single Atlas stent and a spherical 3-dimensional (3D) Stryker coil.

METHODS

A retrospective review of 35 patients who underwent SSAC of WNBA performed via a shouldering and framing with a single Atlas stent and a spherical 3D Stryker coil from 2018 to 2019. Data collection were performed on baseline demographics, clinical presentation, aneurysm characteristics, angiographic and functional outcomes, and perioperative and postoperative complications.

RESULTS

Of 35 patients, the mean age was 59.9 ± 11.6 years and 25/35 (71.4%) were women. The mean aneurysm diameter was 6.3 ± 3.4 mm, the mean neck size was 3.9 ± 1.3 mm, and the mean dome-to-neck ratio was 1.5 ± 0.6. Initial complete/near-complete occlusion was demonstrated in 30/35 (85.7%) patients. On angiographic follow-up at a mean of 6 months, 9/24 (37.5%) patients showed progressive thrombosis, 13/24 (54.2%) showed stable occlusion, and 2/24 (8.5) showed recanalization. Thromboembolic events occurred in 2/35 (5.7%) patients, intraoperative technical complications occurred in 2/35 (5.7%) patients, and access-site complications occurred in 2/35 (5.7%) patients. The were no cases of retreatment, rehemorrhage, or procedural-related permanent morbidity or mortality.

CONCLUSIONS

Coil embolization performed via shouldering with a single Atlas stent and framing with a spherical 3D Stryker coil is a feasible, safe, and effective neuroendovascular treatment for WNBAs.

Pleth variability index predicts hypotension during anesthesia induction

BACKGROUND

The pleth variability index (PVI) is a new algorithm used for automatic estimation of respiratory variations in pulse oximeter waveform amplitude, which might predict fluid responsiveness. Because anesthesia-induced hypotension may be partly related to patient volume status, we speculated that pre-anesthesia PVI would be able to identify high-risk patients for significant blood pressure decrease during anesthesia induction.

METHODS

We measured the PVI, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) in 76 adult healthy patients under light sedation with fentanyl to obtain pre-anesthesia control values. Anesthesia was induced with bolus administrations of 1.8 mg/kg propofol and 0.6 mg/kg rocuronium. During the 3-min period from the start of propofol administration, HR, SBP, DBP, and MAP were measured at 30-s intervals.

RESULTS

HR, SBP, DBP, and MAP were significantly decreased after propofol administration by 8.5%, 33%, 23%, and 26%, respectively, as compared with the pre-anesthesia control values. Linear regression analysis that compared pre-anesthesia PVI with the decrease in MAP yielded an r value of -0.73. Decreases in SBP and DBP were moderately correlated with pre-anesthesia PVI, while HR was not. By classifying PVI >15 as positive, a MAP decrease >25 mmHg could be predicted, with sensitivity, specificity, positive predictive, and negative predictive values of 0.79, 0.71, 0.73, and 0.77, respectively.

CONCLUSION

Pre-anesthesia PVI can predict a decrease in MAP during anesthesia induction with propofol. Its measurement may be useful to identify high-risk patients for developing severe hypotension during anesthesia induction.

Airway problems related to laryngeal mask airway use associated with an undiagnosed epiglottic cyst

This report describes airway management difficulties in a patient with an asymptomatic and undiagnosed epiglottic cyst. Mask ventilation after induction of general anesthesia was uneventful. Insertion of an LMA resulted in inadequate ventilation. Fiberoptic intubation through an intubating LMA was impossible because the LMA pushed the cyst into the laryngeal inlet. Fibreoptic intubation, assisted by the use of a direct laryngoscope without the LMA was uneventful. Preoperative craniocervical scans performed for assessment of other conditions may reveal asymptomatic pathology in the airway.

Relaxing intraoperative natural sound blunts haemodynamic change at the emergence from propofol general anaesthesia and increases the acceptability of anaesthesia to the patient

BACKGROUND

It is known that auditory input, such as comforting music or sound, blunts the human response to surgical stress in conscious patients under regional anaesthesia. As auditory perception has been demonstrated to remain active under general anaesthesia, playing comforting sounds to patients under general anaesthesia might also modulate the response of these patients to surgical stress.

METHODS

Fifty-nine patients scheduled for laparoscopic cholecystectomy were anaesthetized with propofol general anaesthesia in combination with epidural anaesthesia. Natural sounds, chosen preoperatively by each patient as being comforting, were played to 29 patients using headphones during surgery (S group) and the remainder of the patients (n = 30) were fitted with dummy open-type headphones (N group). We compared the haemodynamic change during anaesthesia and the acceptability of anaesthetic practice between the two groups in a randomized double-blind design.

RESULTS

There were no differences in haemodynamics between the S and N groups during surgery. During the emergence from anaesthesia, the mean blood pressure and heart rate gradually increased; both parameters were significantly higher in the N group than in the S group. Postoperatively, patients in the S group perceived the experience of anaesthesia as significantly more acceptable than did those in the N group.

CONCLUSION

These findings indicate that allowing patients comforting background sounds during general anaesthesia may blunt haemodynamic changes upon emergence from general anaesthesia and increase the acceptability of the experience of anaesthesia.

Induction and mechanism of apoptotic cell death by propofol in HL-60 cells

BACKGROUND

Apoptosis (programmed cell death) occurs in various physiological and pathological conditions, exhibits a characteristic mechanism of intracellular sequential reaction and may be involved in determining clinical outcome. The antioxidant activity of propofol (2,6-diisopropylphenol) together with the stimulating effect of protein kinase C suggests that propofol might have the potential to modulate apoptosis. Thus, it is of both clinical interest and biomedical importance to investigate and clarify the effect and mechanism of propofol upon the intracellular reactions underlying apoptotic cell death.

METHODS

The effect of propofol on apoptosis was investigated using cultured human promyelocytic leukemia HL-60 cells. This well-characterized cell line is useful for the study of apoptosis because the various biochemical steps occurring during apoptosis have been well documented.

RESULTS

Treatment of HL-60 cells with propofol resulted in growth inhibition with the formation of apoptotic bodies in a concentration-dependent manner. DNA fragmentation and ladder formation was also observed in a concentration-dependent manner. Propofol treatment resulted in activation of caspase-3, -6, -8 and -9, thereby suggesting that cell surface death receptor activation of the caspase cascade mediates propofol-induced apoptosis with consequent formation of the cleaved product of Bid (a pro-apoptotic Bcl-2 family member protein) and activation of the mitochondrial pathway with cytosolic release of cytochrome c.

CONCLUSION

Propofol may induce apoptosis, which is dependent on the mechanism that activates both the cell surface death receptor pathway and the mitochondrial pathway.

Echocardiographic diagnosis of extrapericardial tamponade due to dilated gastric roll following oesophagectomy

A complication of lower thoracic oesophagectomy for oesophageal carcinoma is reported. Extrapericardial tamponade was caused by a dilated retrosternal gastric roll. Echocardiography was useful for diagnosis. Diagnosis, investigation and management of this unusual but life-threatening complication are discussed. Transthoracic echocardiography is a useful and practical investigation for the evaluation of complications of oesophagectomy.

LIRF, a gene induced during hippocampal long-term potentiation as an immediate-early gene, encodes a novel RING finger protein

We describe here an LTP-induced gene, LIRF, which encodes a novel protein with RING finger and B30.2 domains in its N- and C-terminal portions, respectively. Each domain is encoded by one exon, suggesting that the organization of the gene was generated by exon shuffling. The amino acid sequences of the mouse, rat, and human LIRF proteins are highly conserved and contain a putative PEST sequence. LIRF is an immediate-early gene in hippocampal granule cells, and its expression is upregulated immediately after the induction of long-lasting long-term potentiation at perforant pathway-dentate gyrus synapses and returns to the basal level within 150 min. A heterologously expressed LIRF protein fused to EGFP localizes specifically to the cytoplasm in COS-7 cells. These findings suggest a possible involvement of LIRF in a limited, early phase of synaptic plasticity.

Effect of mild therapeutic hypothermia on phenytoin pharmacokinetics

The authors examined the effect of mild therapeutic hypothermia on phenytoin pharmacokinetics in 14 patients with brain damage. Each patient was given phenytoin during and after mild therapeutic hypothermia. Plasma concentrations of total phenytoin, unbound phenytoin, and 5-(p-hydroxyphenyl)-5-phenylhydantoin (5-p-HPPH), the major metabolite of phenytoin, were measured. Pharmacokinetic parameters during and after mild therapeutic hypothermia were compared. Plasma concentrations of total and unbound phenytoin were significantly higher during hypothermia than after hypothermia. The area under the plasma concentration-time curve (zero to infinity) was increased by 180% and mean residence time was prolonged by 180% during hypothermia compared with the corresponding values after hypothermia. Moreover, the elimination constant (ke) was decreased by 50% and elimination clearance of phenytoin was decreased by 67% during hypothermia compared with the corresponding values after hypothermia. The plasma concentration of 5-p-HPPH was significantly lower during hypothermia than after hypothermia. These findings suggest that phenytoin metabolism is inhibited by mild therapeutic hypothermia.

Analysis of tyrosine phosphorylation-dependent protein-protein interactions in TrkB-mediated intracellular signaling using modified yeast two-hybrid system

Activated receptor tyrosine kinases induce a large number of tyrosine phosphorylation-dependent protein-protein interactions through which they mediate their various ligand-exerted functions including regulation of proliferation, differentiation and survival. TrkB receptor tyrosine kinase activated by binding of brain-derived neurotrophic factor (BDNF) also stimulates various protein interactions in a tyrosine phosphorylation-dependent manner in neuronal cells. To examine tyrosine phosphorylation-dependent interactions stimulated by active TrkB, we developed a modified yeast two-hybrid system, which we call the yeast two-and-a-half-hybrid system. In this system, yeast was engineered to express a tyrosine kinase domain of TrkB as an effector, in addition to two fusion proteins with GAL4 DNA-binding and GAL4 activation domains as bait and prey proteins, respectively. Using this system with Shp2 as the bait, we demonstrated that Shp2 interacts directly with BIT/SHPS-1 (also called SIRP) and Grb2 depending on tyrosine phosphorylation mediated by TrkB. Furthermore, we screened an adult human brain cDNA library with the yeast two-and-a-half-hybrid system in order to identify other Shp2-binding proteins in TrkB-stimulated tyrosine phosphorylation signaling. We found that fibroblast growth factor receptor substrate 2beta (FRS2beta), also called SNT2, interacts with Shp2 dependently on TrkB-mediated tyrosine phosphorylation of FRS2beta/SNT2. Therefore, we show that the two-and-a-half-hybrid system is a powerful tool for studying tyrosine phosphorylation-dependent protein-protein interactions in intracellular signaling pathways stimulated by TrkB receptor tyrosine kinase.

Cytochrome P4502B6 and 2C9 do not metabolize midazolam: kinetic analysis and inhibition study with monoclonal antibodies

We determined the contribution of cytochrome P450 (CYP) isoforms to the metabolism of midazolam by kinetic analysis of human liver microsomes and CYP isoforms and by examining the effect of chemical inhibitors and monoclonal antibodies against CYP isoforms in vitro. Midazolam was metabolized to 1'-hydroxymidazolam (1'-OH MDZ) by human liver microsomes with a Michaelis-Menten constant (Km) of 4.1 (1.0) (mean (SD)) micromol litre(-1) and a maximum rate of metabolism (Vmax) of 5.5 (1.1) nmol min(-1) mg protein(-1) (n = 6). Of the nine representative human liver CYP isoforms, CYP1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4 and 3A5, three (CYP2B6, 3A4 and 3A5) showed midazolam 1'-hydroxylation activity, with Kms of 40.7, 1.7 and 3.0 micromol litre(-1), respectively, and Vmax values of 12.0, 3.3 and 13.2 nmol min(-1) nmol P450(-1), respectively (n = 4). Midazolam 1'-hydroxylation activity of human liver microsomes correlated significantly with testosterone 6beta-hydroxylation activity, a marker of CYP3A activity (r2 = 0.77, P = 0.0001), but not with S-mephenytoin N-demethylation activity, a marker of CYP2B6 activity (r2 < 0.01, P = 0.84) (n = 11). Troleandomycin and orphenadrine, chemical inhibitors of CYP isoforms, inhibited the formation of 1'-OH MDZ by human liver microsomes. Monoclonal antibody against CYP3A4 inhibited the formation of 1'-OH MDZ by 79%, whereas monoclonal antibody against CYP2B6 had no effect on midazolam 1'-hydroxylation by human liver microsomes (n = 5). These results indicate that only CYP3A4, but not CYP2B6 or CYP2C, is involved in the metabolism of midazolam in vitro.

The effects of norepinephrine and prostaglandin E1 on pharmacokinetics of lidocaine in isolated perfused rat liver

We hypothesized that depression of liver function by norepinephrine can be improved by prostaglandin E1. Isolated perfused rat liver was selected as an experimental model, since the flow rate can be regulated in it. Twenty-one rats were randomly allocated to three groups: control, norepinephrine, and norepinephrine and prostaglandin E1 groups. The liver was perfused in a recirculating system at a constant flow rate of 20 ml/min. After administration of two milligrams of lidocaine in each group, lidocaine and monoethylglycinexylidide concentrations in the recirculating system were measured. Lidocaine pharmacokinetics were analyzed using the SAAM II program, including metabolic rate from lidocaine to monoethylglycinexylidide using time-concentration curves. Norepinephrine significantly increased perfusion pressure and the area under the time-concentration curve for lidocaine. Norepinephrine decreased the clearance and the elimination rate constant of lidocaine compared with those in the control group. Although administration of prostaglandin E1 after infusion of norepinephrine did not significantly change perfusion pressure, it significantly (p < 0.05) improved metabolic rate, clearance and the elimination rate constant of lidocaine in the isolated rat liver model.

Involvement of human liver cytochrome P4502B6 in the metabolism of propofol

AIMS

To determine the cytochrome P450 (CYP) isoforms involved in the oxidation of propofol by human liver microsomes.

METHODS

The rate constant calculated from the disappearance of propofol in an incubation mixture with human liver microsomes and recombinant human CYP isoforms was used as a measure of the rate of metabolism of propofol. The correlation of these rate constants with rates of metabolism of CYP isoform-selective substrates by liver microsomes, the effect of CYP isoform-selective chemical inhibitors and monoclonal antibodies on propofol metabolism by liver microsomes, and its metabolism by recombinant human CYP isoforms were examined.

RESULTS

The mean rate constant of propofol metabolism by liver microsomes obtained from six individuals was 4.2 (95% confidence intervals 2.7, 5.7) nmol min(-1) mg(-1) protein. The rate constants of propofol by microsomes were significantly correlated with S-mephenytoin N-demethylation, a marker of CYP2B6 (r = 0.93, P < 0.0001), but not with the metabolic activities of other CYP isoform-selective substrates. Of the chemical inhibitors of CYP isoforms tested, orphenadrine, a CYP2B6 inhibitor, reduced the rate constant of propofol by liver microsomes by 38% (P < 0.05), while other CYP isoform-selective inhibitors had no effects. Of the recombinant CYP isoforms screened, CYP2B6 produced the highest rate constant for propofol metabolism (197 nmol min-1 nmol P450-1). An antibody against CYP2B6 inhibited the disappearance of propofol in liver microsomes by 74%. Antibodies raised against other CYP isoforms had no effect on the metabolism of propofol.

CONCLUSIONS

CYP2B6 is predominantly involved in the oxidation of propofol by human liver microsomes.

Propofol versus midazolam regarding their antioxidant activities

Propofol and midazolam are commonly used as sedatives for critically ill patients. These patients usually suffer from the pathologic effects of oxidative stress, predominantly caused by an imbalance between the generation of reactive oxygen species and the antioxidant defense system. Therefore, the antioxidant activities of propofol and midazolam may be of clinical importance. We investigated the activities of these two sedatives against hydrophilic or lipophilic peroxyl radicals in a homogeneous solution and in the presence of erythrocyte membranes. A chemical analysis of the homogeneous solution revealed that propofol efficiently scavenged hydrophilic peroxyl radicals (50% inhibitory concentration [IC50] = 1.3 x 10(-4) M), whereas midazolam efficiently scavenged lipophilic radicals (IC50 = 1.5 x 10(-5) M). Further, in membrane systems, propofol inhibited the oxidative damage induced by either hydrophilic or lipophilic radicals (IC50 = 1.5 x 10(-5) M for hydrophilic radicals and IC50 = 3.0 x 10(-4) M for lipophilic radicals), whereas midazolam did very little. In previous studies, we demonstrated that antioxidant activity is highly affected by the location and properties of the reaction site. The discrepancy in antioxidant activity between a homogeneous condition and in the presence of membranes can be well explained by this concept, and again emphasizes the importance of membranes in determining antioxidant activity. To further understand the biologic significance of these antioxidant properties, the effect of the two agents on endothelium-dependent relaxation was studied. Application of oxidative stress to aortic rings by treating them with peroxyl radicals led to a significant blockade of acetylcholine-induced relaxation after submaximal contraction with phenylephrine. Propofol pretreatment greatly attenuated the impairment in comparison with midazolam, which agrees with the concept of antioxidant activity in the presence of membranes. The results of the present study suggest that propofol has a greater potential to reduce oxidative stress than midazolam.

A retrospective pilot study of indocyanine green enhanced diode laser photocoagulation for subfoveal choroidal neovascularization associated with age-related macular degeneration

PURPOSE

The effectiveness and limitations of indocyanine green (ICG) enhanced diode laser photocoagulation in treating subfoveal choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD) were investigated retrospectively.

METHODS

Thirty-eight eyes of 37 patients with subfoveal CNV received ICG enhanced diode laser (wavelength, 805 nm) photocoagulation in our preliminary series. Nineteen eyes had classic CNV and the others had occult CNV, which was well-delineated on ICG angiography. The rate of anatomical success and functional outcomes were investigated. Factors prognostic of a final visual acuity of 0.1 or better were analyzed. The follow-up period ranged from 6 to 51 months (mean +/- SD = 26.5 +/- 14.4 months).

RESULTS

Occlusion of CNV was achieved in 35 of 38 eyes (92%), and 7 eyes (18%) showed recurrence, which was occluded by retreatment in all but 1 eye. Ten eyes (26.3%) showed improvement of visual acuity; 16 (42.1%) showed no change; and in 12 eyes (31.6%) visual acuity deteriorated. Factors prognostic of a final visual acuity of 0.1 or better were good preoperative visual acuity (Mann-Whitney U-test, P =.0028), and a relatively short distance between the edge of laser burns and the center of the foveal avascular zone (unpaired t-test, P =.0285).

CONCLUSION

Indocyanine green enhanced photocoagulation achieved a higher anatomical success rate but functional outcomes equal to those with argon or krypton laser photocoagulation. A controlled prospective study is necessary to prove the efficacy of this treatment.

The calcium-independent protein kinase C participates in an early process of CD3/CD28-mediated induction of thymocyte apoptosis

Thymocyte negative selection eliminates self-reactive clones and involves both a T-cell receptor (TCR)/CD3-mediated signal and a costimulatory signal, which can be delivered via CD28. Anti-CD3/anti-CD28-triggered apoptosis in isolated CD4+CD8+ thymocytes in vitro provides a basic model for negative selection. Effects of isoform-selective and non-isoform-selective inhibitors of protein kinase C (PKC) on this apoptotic process suggest that activation of Ca2+-independent PKC isoforms during the first 2-3 hr of culture is essential for inducing apoptosis, and that Ca2+-dependent PKC isoforms may be influential, but not essential, for apoptosis. To assess the CD3/CD28-mediated activation of PKC in the apoptotic process, we prepared CD4+CD8+ thymocytes (without contamination with cells that had received negative or positive selection signals in vivo) by establishing TCR-transgenic mice with RAG-2-deficient and non-selecting major histocompatibility complex (MHC) backgrounds, in addition to a CD4+CD8+ thymocyte-enriched population from normal mice. Translocation of Ca2+-independent PKC from the cytosolic fraction to the particulate fraction of CD4+CD8+ thymocytes was induced by CD3/CD28-mediated stimulation, but not by CD3- or CD28-mediated stimulation alone, and peaked 2 hr after the start of culture. The kinase activity of the translocated Ca2+-independent PKC was dependent on cofactors in vitro, indicating that novel (n)PKC, but not atypical (a)PKC or a proteolytic PKC fragment, was responsible for the activity. Immunoblotting analysis indicated that the nPKC-theta isoform was the major contributor among nPKC isoforms, and that the classical (c)PKC-alpha isoform was the major contributor among cPKC isoforms. These results suggest that activation of nPKC (especially the theta isoform) in CD4+CD8+ thymocytes is involved in a pathway for negative selection.

Interrelation between oxygen tension and nitric oxide in the respiratory system

To understand the relationship between oxygen tension and nitric oxide (NO) function, one animal and two human studies were designed. In the animal study, the effect of NO in inducing the relaxation of aortic specimens was significantly lower by 68% under 480 mm Hg of oxygen tension than under 28 mm Hg, indicating that oxygen tension has an important role in determining the biological effects of NO. In a clinical analysis with nonsmokers (n = 23), the alveolar-to-arterial difference for oxygen (A-aDO(2)) was reciprocally correlated with exhaled NO concentrations (r = 0.53). Because NO concentration in the lower respiratory zone depends partly on the amount of inspirable NO originating in the upper airway, a well-ventilated area, requiring much perfusion, could receive greater amounts of NO than a poorly ventilated one. Thus, the reciprocal relation of A-aDO(2) with the concentration of exhaled NO is not necessarily incompatible with the effect of hypoxic pulmonary vasoconstriction in ventilation-to-perfusion (V'A/Q') imbalance. In our third experiment, with nonsmokers (n = 21), pure oxygen inhalation during mechanical ventilation significantly decreased the concentration of exhaled NO and enhanced A-aDO(2), indicating a relationship between NO and oxygen similar to that observed in the animal experiment. These findings led us to conclude that a positive relation between exhaled NO and blood oxygenation efficiency exists in the respiratory system, and further, that oxygen might affect this relationship. Thus, the relative balance of NO and oxygen concentrations may be another factor for consideration in respiratory function.

Venous blood flow measurement by determination of change in venous hemoglobin saturation

OBJECTIVE

To evaluate a method of measuring venous blood flow in vitro by using the Fick principle and change in saturation of venous blood and to apply the method to the clinical measurement of hepatic blood flow.

DESIGN

Experimental study using an in vitro model and clinical study for critically ill patients.

SETTING

Department of Anesthesiology and Intensive Care Medicine in Osaka City University Medical School.

MODEL

Human blood deoxygenated by bubbling of nitrogen was circulated in a closed circuit at 10-120 mL/min by a roller pump. A fiber optic sensor was attached to the circuit for continuous monitoring of hemoglobin saturation.

PATIENTS

Eight critically ill patients, aged 54.3 +/- 15.1 yrs, were studied.

INTERVENTIONS

Hemoglobin saturation was changed in the in vitro study by the injection of 0.2 mL of oxygenated blood. Signals from the optical fiber were analogue-digital converted and recorded in a computer. In the clinical study, an oximetry catheter was inserted into the inferior vena cava (IVC) via the femoral vein. Arterial blood (10 mL) was drawn from the radial artery, and injected into the IVC. The changes in oxygen saturation in the venous blood were recorded.

MEASUREMENTS AND MAIN RESULTS

Blood flow was calculated using the Fick principle, assuming that all the injected blood passes through the sensor. In vitro estimation of blood flow was well correlated with the actual flow (r2 = .94). IVC blood flow was measured above and below the merging point of the hepatic vein. The difference of the two values was assumed to represent hepatic blood flow. IVC blood flow was calculated by the same method as for the in vitro study. The blood flows in the IVC above and below the anastomosis with the hepatic vein were 2.82 +/-0.56 (SD) Umin and 1.96 +/- 0.61 (SD) L/min. Average estimated hepatic blood flow was 0.86 L/min (range, 0.34-1.75 Umin).

CONCLUSION

We examined the accuracy and reliability of this new method in the present in vitro study. This method may be clinically useful for measuring hepatic blood flow.

[Causes of renal dysfunction during the anhepatic phase in patients for orthotopic liver transplantation and their postoperative renal function]

This study was carried out to clarify causes of renal dysfunction during the anhepatic phase in orthotopic liver transplantation (OLT) with venovenous bypass and to show how the deterioration impacted on postoperative renal function. The 44 consecutive patients with normal preoperative renal function who underwent OLT in Royal Prince Alfred Hospital were classified into two groups according to creatinine clearance (Ccr) during the anhepatic phase. Group 1 consisted of 27 patients whose Ccr levels levels were kept above 60 ml.min-1.m-2 and group 2 consisted of 17 patients under 60 ml.min-1.m-2. In group 2, preoperative International Normalized Ratio for prothrombin was higher and blood transfusion volume before revascularization was significantly lager than group 1. There were significant differences in haemodynamics just before revascularization (mean arterial pressure 95 +/- 14 vs 83 +/- 14 mmHg, pulmonary artery wedge pressure 16 +/- 5 vs 11 +/- 5 mmHg, cardiac index 4.6 +/- 1.3 vs 4.0 +/- 0.9 l.min-1.m-2, group 1 vs group 2, mean +/- SD, P < 0.05). Serum creatinine levels in group 2 were significantly higher postoperatively. It is suggested that bleeding due to insufficient preoperative coagulability caused haemodynamic instability which deteriorated renal function during the anhepatic phase and the deterioration impacted on postoperative renal function.

Area under the plasma concentration-time curve of inorganic fluoride following sevoflurane anesthesia correlates with CYP2E1 mRNA level in mononuclear cells

BACKGROUND

Because the amount of inorganic fluoride released after anesthesia with sevoflurane depends on the dose of administered sevoflurane and cytochrome P450 (CYP) 2E1 activity in the liver, a reliable and noninvasive probe for CYP2E1 would be useful for predicting plasma inorganic fluoride levels after anesthesia. In this study, the authors evaluated the relation between plasma concentration of inorganic fluoride after sevoflurane anesthesia and CYP2E1 mRNA level in mononuclear cells.

METHODS

Twenty patients (American Society of Anesthesiologists physical status I), aged 20-68 yr undergoing body surface surgery with general anesthesia with sevoflurane were enrolled. One milliliter of blood was obtained before administration of sevoflurane and mononuclear cells were obtained. Levels of CYP2E1 mRNA in mononuclear cells were measured by competitive reverse transcription polymerase chain reaction with a specific primer and competitor for CYP2E1 mRNA.

RESULTS

There was a significant correlation between level of CYP2E1 mRNA in mononuclear cells and the area under the plasma concentration-time curve of plasma inorganic fluoride from the beginning of sevoflurane administration to infinity in uninduced and uninhibited patients (r2 = 0.56; P < 0.01).

CONCLUSIONS

Area under the plasma concentration-time curve of inorganic fluoride after sevoflurane anesthesia correlates with CYP2E1 mRNA in mononuclear cells in peripheral blood.

Preoperative epidural morphine using double-catheter technique for esophagectomy

This study was undertaken to determine whether preoperative epidural morphine using double-catheter technique would improve postoperative analgesia in patients undergoing esophagectomy with or without continuous intraoperative epidural lidocaine in a randomized double-blind and controlled manner. Thirty patients undergoing esophagectomy for esophageal cancer received preoperative epidural morphine 2 mg at T 6-7 and 2 mg at L 3-4 through the catheters, respectively. Thereafter, continuous thoracic epidural infusion of either 1% lidocaine (lidocaine group, n = 15) or normal saline solution (control group, n = 15) at 6 ml/h was initiated. After surgery, mean verbal rating scale of pain (0 to 10) at rest was maintained below 4 and pain on deep breathing was maintained mild in all patients in both groups. There was no significant difference in these values between the groups. In conclusion, preoperative epidural morphine using double-catheter technique provided adequate analgesia following esophagectomy. The addition of intraoperative continuous epidural lidocaine did not improve analgesia.

Propofol decreases the clearance of midazolam by inhibiting CYP3A4: an in vivo and in vitro study

OBJECTIVE

To examine the effect of propofol on the pharmacokinetics of midazolam in vivo and to elucidate the mechanism of the pharmacokinetic changes of midazolam by propofol with the use of human liver microsomes and recombinant CYP3A4.

METHODS

In an in vivo, double-blind randomized study, 24 patients received 0.2 mg/kg midazolam and either 2 mg/kg propofol (propofol group) or placebo (placebo group) for induction of anesthesia. In the propofol group, continuous infusion of propofol at 9 mg/kg/h was started immediately after the bolus infusion of propofol and was maintained for an hour. In the placebo group the same dose of soybean emulsion as a placebo was given and infused intravenously for an hour instead of propofol. In an in vitro study the effect of propofol on the metabolism of midazolam was studied with human liver microsomes and recombinant CYP3A4.

RESULTS

In the propofol group the mean clearance of midazolam was decreased by 37% (P = .005) and the mean elimination half-life was prolonged by 61% (P = .04) compared with the placebo group. The mean plasma concentrations of 1'-hydroxymidazolam were lower in the propofol group than in the placebo group at 5, 10, 15, 20, and 30 minutes after midazolam was administered (P < .05). The mean (+/-SD) Michaelis-Menten constant for midazolam 1'-hydroxylation by human liver microsomes was 5.6 +/- 3.3 micromol/L. The formation of 1'-hydroxymidazolam was competitively inhibited by propofol, and the mean inhibition constant was 56.7 +/- 16.6 micromol/L. The mean Michaelis-Menten constant and mean inhibition constant values for midazolam 1'-hydroxylation by recombinant CYP3A4 were 4.0 micromol/L and 61.0 micromol/L, respectively, consistent with the mean values obtained from human liver microsomes.

CONCLUSION

Propofol decreases the clearance of midazolam, and the possible mechanism is the competitive inhibition of hepatic CYP3A4.

Fentanyl inhibits metabolism of midazolam: competitive inhibition of CYP3A4 in vitro

Fentanyl decreases clearance of midazolam administered i.v., but the mechanism remains unclear. To elucidate this mechanism, we have investigated the effect of fentanyl on metabolism of midazolam using human hepatic microsomes and recombinant cytochrome P450 isoforms (n = 6). Midazolam was metabolized to l'-hydroxymidazolam (l'-OH MDZ) by human hepatic microsomes, with a Michaelis-Menten constant (K(m)) of 5.0 (SD 2.7) mumol litre-1. Fentanyl competitively inhibited metabolism of midazolam in human hepatic microsomes, with an inhibition constant (Ki) of 26.8 (12.4) mumol litre-1. Of the seven representative human hepatic P450 isoforms, CYP1A2, 2A6, 2C9, 2C19, 2D6, 2E1 and 3A4, only CYP3A4 catalysed hydroxylation of midazolam, with a K(m) of 3.6 (0.8) mumol liter-1. Fentanyl competitively inhibited metabolism of midazolam to l'-OH MDZ by CYP3A4, with a Ki of 24.2 (6.8) mumol litre-1, comparable with the Ki obtained in human hepatic microsomes. These findings indicate that fentanyl competitively inhibits metabolism of midazolam by CYP3A4.

Oral clonidine to control hypertension after head injury

Clonidine, an alpha2 agonist, was administered through a nasogastric tube for the treatment of hypertension in a head-injury patient with elevated plasma catecholamines. Haemodynamic parameters were stabilized with a reduction in sympathetic nervous activity. The plasma clonidine concentration, measured by radioimmunoassay, rapidly increased following the administration. After cessation of oral administration of clonidine, mean arterial blood pressure gradually increased. So clonidine was again administered orally and good blood pressure control was achieved and no change in consciousness level was observed. Oral clonidine was useful and effective for hypertension in this head injury patient.

Induction of thymocyte apoptosis by Ca2+-independent protein kinase C (nPKC) activation and its regulation by calcineurin activation

Glucocorticoids appear to participate in apoptosis of unselected CD4(+)CD8(+) thymocytes. Activation of Ca2+-independent novel protein kinase C (nPKC) precedes glucocorticoid-induced thymocyte apoptosis, while proper levels of Ca2+-dependent protein kinase C (cPKC) and calcineurin activities contribute to rescue thymocytes. To clarify the role of nPKC in thymocyte apoptosis, murine thymocytes were stimulated with the diterpene diester, ingenol 3, 20-dibenzoate (IDB). IDB induced selective translocation of nPKC-delta, -epsilon, and -theta and PKC-mu from the cytosolic fraction to the particulate fraction and induced morphologically typical apoptosis through de novo synthesis of macromolecules. The apoptosis was also induced by thymeleatoxin, a diterpene ester, at relatively high concentrations that induced translocation of cPKC, nPKC-theta, and PKC-mu. The IDB- or thymeleatoxin-induced death was inhibited by non-isoform-selective PKC inhibitors, but not by their structural analogs with weak PKC-inhibitory activity or the selective inhibitor of cPKC and PKC-mu, Gö 6976. The death was also inhibited by calcium ionophore ionomycin at concentrations within a narrow range. The range corresponded to the concentration range that contributes to the inhibition of glucocorticoid-induced apoptosis. The antiapoptotic effect was canceled by the immunosuppressant FK506 but not by rapamycin. These results indicate that activation of nPKC, especially nPKC-theta, induces apoptosis in thymocytes and that calcineurin activation regulates the apoptosis.

Oral clonidine for sedation and analgesia in a burn patient

Clonidine has both analgesic and sedative actions, and it has been used in a variety of settings as a sedative, or both. We administered oral clonidine with intravenous ketamine to a burn patient to control severe pain. Clonidine produced good analgesia and sedation. In addition, clonidine counterbalanced the sympathetic stimulation of ketamine by virtue of its action in reducing sympathetic outflow. The combination of these two drugs may be useful for burn patients with hypertension or myocardial ischemia.

The pharmacokinetic change of lidocaine by catecholamines using isolated perfused rat liver (IPRL)

We hypothesized that changes in the pharmacokinetics of lidocaine might reveal changes in portal circulation induced by catecholamines. Isolated perfused rat liver (IPRL) was selected as an experimental model, since experimental conditions in this model could be regulated. The liver was perfused with a recirculating system at a constant flow rate of 20 ml/min. Two milligrams of lidocaine was administered along with one of three drugs, dopamine, norepinephrine or adenosine triphosphate. The fractional transfer rate constants, k21 and k12, from medium to liver and liver to medium, respectively, and ke, the elimination rate constant, were calculated using a two-compartment model with the SAAM II program. Curves of decay of lidocaine from the recirculating medium consisted of a fast and a slow component. Norepinephrine and high-dose dopamine significantly increased k12, while low-dose dopamine significantly increased k21 and ke compared with control values. Thus, norepinephrine and high-dose dopamine increased lidocaine transfer rate from liver to medium, while low-dose dopamine increased the transfer rate from medium to liver and the rate of elimination from liver. These findings suggest that norepinephrine and high-dose dopamine inhibit hepatic drug uptake and that low-dose dopamine improves uptake in IPRL.

Elevated methemoglobin in patients with sepsis

BACKGROUND

It has been reported that large amounts of nitric oxide (NO) are released in patients with sepsis. NO is converted to methemoglobin and nitrate. This study was designed to determine whether blood methemoglobin levels were increased in patients with sepsis or septic shock.

METHODS

Forty-five critically ill patients including 8 with sepsis but without shock, 6 with septic shock and 31 non-septic patients were enrolled in the study. For septic and septic shock patients, blood methemoglobin concentrations were measured during sepsis or septic shock and at the time of recovery or just before the onset of sepsis. For the remaining non-septic patients, methemoglobin concentrations were measured at ICU admission and discharge.

RESULTS

Blood methemoglobin levels in the presence of sepsis or septic shock were significantly (P < 0.05) higher than those in non-septic patients and those at recovery or just before the onset of sepsis in both septic and septic shock patients.

CONCLUSIONS

Blood methemoglobin concentration may be useful as a marker of the onset of sepsis or septic shock.

A role of calcineurin in coreceptor regulation during differentiation of Cd4+Cd8+ T cells

The immunosuppressant FK506 inhibits thymocyte positive selection. Calcineurin, a FK506-sensitive Ca2+/calmodulin-dependent protein phosphatase, is presumed to be involved in this event without direct evidence. We have previously shown that moderate stimulation of CD4(+)CD8(+) thymocytes with a combination of the calcium ionophore ionomycin and phorbol myristate acetate mimics positive selection events including downregulation of CD8 expression. Moderate stimulation of a CD4(+)CD8(+) T cell line with the same combination of drugs also induced specific downregulation of CD8 expression. FK506 inhibited the CD8 downregulation in both cell types. The T cell line was transfected with an expression vector encoding an active form of calcineurin. The transfectans remained CD4(+)CD8(+), but became CD4(+)CD8(-) or CD4(+)CD8(low) upon stimulation with phorbol myristate acetate alone. The extent of the CD8 downregulation was correlated with the expression level of the mutant calcineurin. These results suggest that the calcium signal for the CD8 downregulation is mainly delivered through calcineurin activation.

The effects of epidural morphine on cardiac and renal sympathetic nerve activity in alpha-chloralose-anesthetized cats

BACKGROUND

Epidural morphine yields postoperative pain relief and hemodynamic stability. However, the effects of epidural morphine on sympathetic tone are unclear. This study was designed to elucidate the effects of epidural morphine on cardiac (CSNA) and renal (RSNA) sympathetic nerve activity by direct measurement in anesthetized cats.

METHODS

Thirty mongrel cats anesthetized with alpha-chloralose were randomly assigned to one of the following five groups: control (0.2 ml/kg thoracic epidural normal saline; n=5); thoracic epidural morphine (n=9); lumbar epidural morphine (n=6); vagotomized, sinoaortic denervated, thoracic epidural morphine (n=5); or intravenous morphine (n=5). Mean arterial pressure (MAP), heart rate (HR), CSNA, and RSNA were measured 0, 15, 30, 60, 90, and 120 min after saline or morphine (200 microg/kg) administration and 15 min after reversal with 200 microg naloxone given intravenously.

RESULTS

In the control group, no changes in measured variables were found after either thoracic epidural saline or intravenous naloxone. Thoracic and lumbar epidural morphine both significantly reduced MAP, HR, CSNA, and RSNA 30 through 120 min after morphine administration (P < 0.05). These changes were reversed by intravenous naloxone. Changes after thoracic epidural morphine administration in vagotomized, baroreceptor-denervated cats were similar to those in intact cats. Intravenous morphine produced no significant changes except for a decrease in MAP, which was reversed by intravenous naloxone.

CONCLUSION

In contrast to intravenous morphine, thoracic and lumbar epidural morphine both inhibited cardiac and renal sympathetic nerve activity and consequently reduced MAP and HR in alpha-chloralose anesthetized cats.

Comparison of survival-promoting effects of brain-derived neurotrophic factor and neurotrophin-3 on PC12h cells stably expressing TrkB receptor

We obtained two PC12h cell lines, PC-pAB1 and PC-pAB2, stably expressing TrkB receptor and investigated the effects of BDNF and NT-3 in these cell lines. The cells differentiated into neuron-like cells in response to BDNF as well as NGF, neurite extension being more rapid in the former case. These TrkB-expressing cells also extended neurites in response to NT-3, which is a nonpreferred ligand of TrkB. Next, we examined the survival-promoting effects of NGF, BDNF, and NT-3 under apoptotic conditions of oxygen toxicity in naive cells and NGF deprivation in differentiated cells. In both cases, BDNF prevented cell death similarly to NGF. NT-3 prevented cell death induced by oxygen toxicity in naive cells, but not that induced by NGF deprivation in differentiated cells. NT-3 induced the tyrosine phosphorylation of TrkB in naive cells, but not in differentiated cells. These results indicate that NT-3 has survival-promoting effects on naive TrkB-expressing PC12h cells, but not on differentiated cells because of its inability to induce the tyrosine phosphorylation of TrkB.

[A comparison of the incidence of postoperative nausea and vomiting after propofol-fentanyl anesthesia and that after nitrous oxide-isoflurane anesthesia]

We compared the incidence of postoperative nausea and vomiting after total intravenous propofol-fentanyl anesthesia (TIVA group) and that after thiamylal-nitrous oxide-isoflurane anesthesia (GOI group) in 60 ASA physical I and II patients for elective abdominal simple total hysterectomy. When the patients returned to the ward, the incidence of nausea was lower in TIVA group than in GOI group (P < 0.05), but no difference was found in the incidence of vomiting between the two groups. There were no differences in the incidence of nausea and vomiting 6 hours after the operation and on the next morning between the two groups. Postoperative pain scores were similar between the two groups, while total postoperative evaluation scores (nausea, vomiting, pain, fever, and sleep disturbance) were lower in TIVA group (P < 0.05). We conclude that TIVA with propofol-fentanyl reduced the incidence of nausea and improved total evaluation scores in the immediate postoperative period.