Physical Properties and Fat Bloom Stability of Compound Chocolates Made with Ternary Fat Blends of Cocoa Butter, 1,3-Dioleoyl-2-stearoyl-triacylglycerol-Fat, and Lauric-Based Cocoa Butter Substitute.

Compound chocolates made of lauric-acid-based cocoa butter substitute (CBS) and cocoa butter (CB) often exhibit serious fat blooms caused by phase separation and polymorphic transformation of CB and CBS triacylglycerols. Herein, we found that the fat bloom of CBS-based chocolates could be completely inhibited by adding fat containing 1,3-dioleoyl-2-stearoyl-triacylglycerol (OSO) to CBS/CB blends. Unlike the CBS/CB chocolates that presented fat blooms within 3 wk under isothermal storage at 15, 20, and 25°C and 15 wk under thermal thawing storage at 15-25°C , no fat blooms appeared in the CBS/CB/OSO compound chocolates under any storage condition up to 6 months. The following key factors are involved in the addition of the OSO fats: the (1) concentration ratio of CB/OSO should be 1/1 such that CB/OSO can form molecular compound crystals and (2) total amount of CB+OSO in the CBS/CB/OSO blends should reach 20%. The solid fat content, hardness, and crystallisation rate of the CBS/CB/OSO blend-based chocolate compound were confirmed to be suitable for chocolate production.

Kinetic Study on Alpha-Form Crystallization of Mixed-Acid Triacylglycerols POP, PPO, and Their Mixture.

The crystallization behavior of the metastable α form of triacylglycerols (TAGs) plays a critical role as a precursor for the crystallization of more stable ß' and ß forms for various applications in food and pharmaceutical products. However, precise analysis of the crystallization kinetics of α has not been performed, likely due to its rapid and complex behavior. This paper presents the observation results of the initial stages of the isothermal crystallization kinetics of α forms of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP), 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (rac-PPO), and molecular compound (MC) crystals of a POP/rac-PPO (1/1) mixture (MCPOP/PPO) using synchrotron radiation time-resolved X-ray diffraction and polarized optical microscopy. In all the TAGs, α crystals with a worm-like morphology started to grow rapidly in the first stage. Then, the α crystals slowly transformed into more stable forms in different manners for different TAG samples. In POP, the conversion was simple, as the α-2 form transformed into γ-3, whereas in rac-PPO, the lamellar distance values of the α-2 form continuously decreased with time and changed into the α-3 form. In the MCPOP/PPO crystals, in contrast, separate crystallization of α-2 of a rac-PPO fraction initially occurred, followed by the crystallization of α-2 of POP, and the two α forms merged into α-2 of MCPOP/PPO. This separate crystallization was caused by large differences in the crystallization kinetics of the α forms of POP and rac-PPO.

Formation and properties of dark chocolate prepared using fat mixtures of cocoa butter and symmetric/asymmetric stearic-oleic mixed-acid triacylglycerols: Impact of molecular compound crystals.

This paper reports an experimental study of the formation and properties of dark chocolate prepared using novel CB alternative fats (CBAs): symmetric (OSatO) and asymmetric (SatSatO) mixed-acid triacylglycerols (TAGs), in which Sat and O represent saturated fatty acids (stearic:S + palmitic:P) and oleic acid moieties, respectively. It was found that the ternary fat mixtures of CB/SatSatO/OSatO with a ratio of CB/(SatSatO + OSatO) of 1:1 formed the most stable ß-form of the double chain length (DCL) structure (ß-2), which revealed sufficient hardness and sharp melting profiles around body temperature without tempering processes. Fat bloom formation was not observed in dark chocolate with CBAs at ratios of CB/SatSatO/OSatO of 50/20/30-50/0/50 during the one-year storage test at temperatures between 15 °C and 30 °C. Overall, the present study has shown that fat mixtures made of CB/SatSatO/OSatO, which are rich in oleic acid moieties, can be employed as a cocoa butter equivalent (CBE) fat without tempering procedures.

Binary Phase Behavior of Saturated-Unsaturated Mixed-Acid Triacylglycerols-A Review.

Most natural lipids contain a complex mixture of individual triacylglycerols (TAGs). An in-depth knowledge of the mixing behavior of TAGs is necessary for the rational design and engineering of food materials. The binary phase diagram of TAGs is a simplified model that can be explored to help foster an understanding of the phase behavior of complex fats and oils. This article reviews recent research on the binary phase behavior of saturated-unsaturated mixed-acid TAGs, with special emphasis on the stearicunsaturated and palmitic-unsaturated diacid TAGs. The occurrence of polymorphic forms and mutual solubility of TAG mixtures are strongly related to the glycerol conformation of the saturated-oleic diacid TAGs; it appears to be most influenced by the chain-length mismatch in saturated-elaidic diacid TAGs. In addition, the polymorphism of pure enantiomers and racemic mixture of chiral TAGs was also reviewed, while the effect of chirality on mixing behavior was discussed.

Phase behavior of binary mixture systems of saturated-unsaturated mixed-acid triacylglycerols: effects of glycerol structures and chain-chain interactions.

We systematically examined the phase behavior of binary mixtures of mixed-acid triacylglycerols (TAGs) containing palmitic and oleic acid moieties 1,3-dioleoyl-2-palmitoyl-glycerol (OPO), 1,2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO), and 1,2-dioleoyl-3-palmitoyl-rac-glycerol (OOP), which are widely present in natural fats and are employed in the food, pharmaceutical, and cosmetic industries. Differential scanning calorimetry and X-ray diffraction methods were applied to observe the mixing behavior of PPO/OPO, OOP/OPO, and PPO/OOP under metastable and stable conditions. The results led to three conclusions: (1) Eutectic behavior was observed in PPO/OPO. (2) Molecular compound (MC) crystals were formed in the mixtures of OOP/OPO and PPO/OOP. (3) However, the MC crystals occurred only under metastable conditions and tended to separate into component TAGs to form eutectic mixture systems after 17 months of incubation. These results were contrary to those of previous studies on 1,3-dipalmitoyl-2-oleoyl glycerol (POP)/OPO and POP/PPO in which the MC crystals were thermodynamically stable. We determined that specific molecular interactions may cause this different phase behavior (stability of POP/OPO and POP/PPO MC crystals and metastability of OOP/OPO and PPO/OOP MC crystals). All results confirm the significant effects of molecular structures of glycerol groups, interactions of fatty acid chains, and polymorphism of the component TAGs on the mixing behavior of mixed-acid TAGs.

Promotional effects of new types of additives on fat crystallization.

We examined the promotional effects of additives on fat crystallization, such as inorganic (talc, carbon nanotube (CNT), and graphite) and organic (theobromine, ellagic acid dihydrate (EAD), and terephthalic acid) materials. The triacylglycerols (TAGs) of trilauroylglycerol (LLL), trimyristoylglycerol (MMM), and tripalmitoylglycerol (PPP) were employed as the fats. The additives (1 wt%) were added to the molten TAGs, and then the mixtures were cooled at a rate of 1°C/min followed by heating at a rate of 5°C/min. The crystallization and melting properties were observed using differential scanning calorimetry, X-ray diffraction, and polarized optical microscope (POM). Consequently, we found that the above six additives remarkably increased the initial temperatures of crystallization (Ti) on cooling without changing the melting temperatures. For example, in the case of LLL, the increases in Ti were 2.6°C (talc), 3.9°C (CNT), 8.1°C (graphite), 1.1°C (theobromine), 2.0°C (EAD), and 6.8°C (terephthalic acid). Very similar effects were observed for the crystallization of MMM and PPP with the six additives. Furthermore, the polymorphs of the first occurring crystals were changed from metastable to more stable forms by many of these additives. The POM observation revealed that the crystallization was initiated at the surfaces of additive particles. This study has shown for the first time that the heterogeneous nucleation of fat crystals can be greatly promoted by new types of additives. Such additives have great potential to promote fat crystallization by not only hydrophobic but also hydrophilic molecular interactions between the fats and additives.

Summary of 15 years experience of awake surgeries for neuroepithelial tumors in tohoku university.

We retrospectively analyzed 15 years experience of awake surgeries for neuroepithelial tumors in Tohoku University. Awake surgeries mostly for language mapping were performed for 42 of 681 newly diagnosed cases (6.2%) and 59 of 985 surgeries including for recurrence (6.0%). When the same histologies and locations as cases resected under awake condition are selected from the parent population treated by radical resection, awake surgeries were most frequently performed for 14 of 55 newly diagnosed cases (25.5%) and 14 of 62 surgeries (22.6%) with grade II gliomas. In the results, 8 of 59 surgeries (13.6%) could not achieve complete language monitoring until the final stage of tumor resection, considered as failed awake surgery. Gross total resection was accomplished in 20 of 42 newly diagnosed cases (47.6%) and 32 of 59 surgeries (54.2%). Mortality rate was 0%. Late severe deficits were observed in 2 of 42 newly diagnosed cases (4.8%) and 3 of 59 surgeries (5.1%). Negative language mapping cases did not suffer severe deficits in both early and late stages. In contrast, high incidence of severe deficits, 3 as early and 2 as late of 8 cases, were identified with failed awake surgery. The overall survival of patients treated by awake surgery compared favorably with those treated without stimulation mapping and with stimulation mapping under general anesthesia. Awake surgery may contribute to improve the outcome of gliomas near eloquent areas by maximizing the tumor resection and minimizing the surgical morbidity.

Crystallization and transformation of polymorphic forms of trioleoyl glycerol and 1,2-dioleoyl-3-rac-linoleoyl glycerol.

This study examined the influence of different thermal treatments on the crystallization and transformation of trioleoyl glycerol (OOO) and 1,2-dioleoyl-3-rac-linoleoyl glycerol (OOL). Two triacylglycerol (TAG) samples were cooled at 0.5-15 °C·min(-1) and heated at 2 and 15 °C·min(-1). The polymorphic characteristics of the two TAGs were analyzed in situ using differential scanning calorimetry, Raman spectroscopy, and synchrotron radiation X-ray diffraction. Multiple polymorphic forms were identified in OOO (α, ß'2, ß'1, ß2, and ß1) and OOL (α, ß'2, and ß'1). Larger quantities of more stable forms (e.g., ß2 and ß1 of OOO and ß'1 of OOL) were obtained when the samples were slowly cooled and heated. In contrast, less stable polymorphs were obtained with increased cooling and heating rates. Polymorphic transformations occurred in either solid-state or melt-mediation and were influenced by heating rates. The results were analyzed by considering the activation energies for crystallization and transformation of stable and less stable polymorphic forms in comparison with previous studies on 1,3-dipalmitoyl-2-oleoyl-glycerol and 1, 3-dioleoyl-2-palmitoyl-glycerol.

Mobilization of the sphenoparietal sinus: a simple technique to preserve prominent frontobasal bridging veins during surgical clipping of anterior communicating artery aneurysms: technical case report.

BACKGROUND AND IMPORTANCE: Bridging veins arising from the frontal base (frontobasal bridging veins, FBBVs) can pose obstacles when performing clipping of anterior communicating artery (ACoA) aneurysms via the pterional approach. Although FBBVs can in general be sacrificed without critical complications to achieve an adequate retraction of the frontal lobe, neurosurgeons sometimes encounter postoperative venous infarction or contusion of the retracted frontal lobe, which may be accounted for by the damage to the venous drainage system. Thus, preservation of intracranial veins is desirable to prevent postoperative venous complications, especially when they are prominent. CLINICAL PRESENTATION: A 66-year-old female patient was revealed to have multiple unruptured aneurysms at the ACoA, bilateral middle cerebral arteries, and the left internal carotid artery. In the first stage of the operation, clipping of the right middle cerebral artery and ACoA aneurysms was performed via a right pterional approach. Because the ACoA aneurysm was located at a high position and projecting posteriorly, a transsylvian "lateral" trajectory was preferred to a subfrontal "anterior" trajectory. Intraoperatively, her FBBV was revealed to be so prominent that the sacrifice would be harmful. Thus, we performed posteriorward displacement of the sphenoparietal sinus extradurally, thereby achieving adequate retraction of the frontal lobe intradurally without sacrificing the FBBV. With this simple technique, the ACoA aneurysm was successfully treated. CONCLUSION: This technique is useful for retracting the frontal lobe sufficiently to enable establishment of an appropriate surgical field for a pterional approach to ACoA aneurysms with prominent FBBVs.

Cardioprotective effects of sarcolemmal and mitochondrial K-ATP channel openers in an experimental model of autoimmune myocarditis. Role of the reduction in calcium overload during acute heart failure.

It has been reported that K-ATP channel openers have a cardioprotective effect in acute ischemia as a pharmacological preconditioning effect. In the present study, the chronic effects of clinical K-ATP channel openers, ie, nicorandil (Nic) and mexiletine (Mex), on cardiac function were evaluated in a rat model of experimental autoimmune myocarditis (EAM). Nicorandil (3 or 10 mg/kg/day) or Mex (10 or 25 mg/kg/day) was administered to the EAM rats, and the effects were compared with those in untreated EAM rats (control EAM) and sham rats without EAM on day 21 (acute phase) or day 60 (chronic phase). In the acute phase, the control EAM rats exhibited a reduced left ventricular ejection fraction (LVEF) and prolonged monophasic action potential duration (MAPD). Neither drug had an affect on the LVEF or degree of myocarditis, but Mex 25 mg suppressed the MAPD prolongation. In the chronic phase, EAM+Nic and EAM+Mex 25 mg exhibited a higher LVEF than the control EAM. Although the control EAM exhibited sustained MAPD prolongation, the other groups showed recovery of the MAPD in the chronic phase. The mitochondorial redox state was lower in the control EAM than in the sham, and EAM+Nic exhibited a similar level of the redox state as the sham in the chronic phase. Nicorandil exhibited a cardioprotective effect through the protection of mitochondrial function. Mexiletine exhibited a cardioprotective effect possibly through a reduction in the calcium overload by shortening the MAPD in the acute phase.

Synchrotron radiation macrobeam and microbeam X-ray diffraction studies of interfacial crystallization of fats in water-in-oil emulsions.

Using macrobeam and microbeam techniques, we performed synchrotron radiation X-ray diffraction (SR-XRD) analyses of fat crystallization in water-in-oil (W/O) emulsion, in combination with DSC and polarized optical microscopic observation. Particular focus was on the crystallization of the fats around water droplets in the W/O emulsion systems using food emulsifiers of polyglycerol polyricinoleate (PGPR) alone (PGPR emulsion), and PGPR and monobehenoylglycerol (MB) (PGPR+MB emulsion). We obtained the following results: (1) macrobeam SR-XRD confirmed that adding MB promoted fat crystallization during cooling, (2) microbeam SR-XRD indicated that the lamellar planes of fat crystals near the water and oil interfaces are arranged almost parallel to the interface planes in both PGPR emulsion and PGPR+MB emulsion, and (3) adding MB resulted in the formation of tiny fat crystals because it promoted crystallization, which occurred both in the bulk oil phase and at the W/O interfaces. The present study is the first to apply microbeam SR-XRD to observe the microscopic features of fat crystallization in W/O emulsion, following fat crystallization in the oil droplets in the oil-in-water (O/W) emulsion (Arima, S.; Ueno, S.; Ogawa, A.; Sato, K. Langmuir 2009, 25, 9777-9784).

Crystallization kinetics of organogels prepared by rice bran wax and vegetable oils.

Rice bran wax (RBX) obtained during rice bran oil purification can form organogels in edible oils. The kinetics of crystallization and the viscous properties of RBX organogels were studied using differential scanning calorimetry (DSC), viscosity changes with varying temperature, hardness measurements by penetrometry, and synchrotron radiation X-ray diffraction (SR-XRD). The organogels were prepared by RBX in concentrations of 1%, 3%, 6%, and 10% on a weight basis in salad oil, olive oil, and camellia oil. The liquid oil type had no significant effect on the melting and crystallization temperatures of the RBX. However, the viscosity and the texture of the organogels differed with liquid oil type, temperature, and RBX concentration. Changes in the viscosity of the RBX organogels were monitored during cooling from 80°C to 20°C. Drastic viscosity changes occurred in accordance with the onset of crystallization in DSC thermographs obtained at a rate of 5°C/min. RBX in the olive oil and camellia oil mixtures had higher viscosity than RBX in the salad oil mixture, which correlates with the hardness obtained in texture measurements at 20°C. SR-XRD was used to clarify the crystal structures of the building blocks of the RBX organogels in salad oil. It was found that the RBX formed crystals with a long spacing of 7.3 ± 1 nm and short spacings of 0.41 ± 1 nm and 0.37 ± 1 nm. The intensity of the long-spacing pattern was remarkably weaker than that of the short-spacing patterns, which demonstrated strong anisotropy in the crystal growth of RBX crystal particles.

Crystallization of fully hydrogenated and interesterified fat and vegetable oil.

Owing to public concern regarding the adverse health effects of trans fatty acids, an alternative technology to trans fats has recently become an important issue. The interesterification of fully hydrogenated vegetable oil and liquid oil blends is one of the most versatile options. This paper reports a physical analysis of high-melting fat (HMF) prepared through the interesterification of fully hydrogenated soybean oil and regular soybean oil, and through fractionation. The thermal and structural properties of the HMF blended with salad oil at a mass ratio of 4:1 (called the HMF blend, hereafter), which was prepared as a model fat blend for margarine, were assessed using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and polarized light microscopy (POM). To observe the polymorphic transformation, all samples were aged after crystallization, and the development of granular crystals during the aging process was observed. We found that the granular crystals are made of SOS/SSO, POS/PSO, and (SOS+POS)/(SSO+PSO) molecular compounds, all of which easily transform into ß form with a double-chain-length structure.

Phase behavior of a binary mixture of 1,3-dipalmitoyl-2-oleoyl-sn-glycerol and 1,3-dioleoyl-2-palmitoyl-sn-glycerol in n-dodecane solution.

The phase behavior of a binary mixture of triacylglycerol (TAG), POP (1,3-dipalmitoyl-2-oleoyl-sn-glycerol), and OPO (1,3-dioleoyl-2-palmitoyl-sn-glycerol) in an organic solvent, n-dodecane, was examined by DSC and synchrotron radiation X-ray diffraction (SR-XRD). In our previous study on POP-OPO mixtures in neat liquid, the formation of molecular compound (MC) crystals of POP/OPO = 50/50 was observed (Minato et al. J. Am. Oil Chem. Soc. 1997, 74, 1213-1220). The purpose of the present study was to determine whether MC is formed in the POP-OPO mixture system in diluted solution when n-dodecane (C(12)) is added to the mixture as a solvent. Two solution systems having weight concentration ratios of POP and OPO to n-dodecane ((POP+OPO):C(12)) of 50:50 (50% solution) and 20:80 (20% solution) were prepared. We found that MC formed at a ratio of POP/OPO = 50/50 in both 50% solution and 20% solution in the stable and metastable states. Differences between the neat liquid and solution systems appeared in two results. In the first, the melting temperatures of MC crystals were lowered from 32.0 degrees C (neat liquid) to 20.4 degrees C (50% solution) and 18.0 degrees C (20% solution). In the second, the beta polymorph of the MC was always observed in the two solutions under the conditions examined in the present study, whereas alpha and beta polymorphs were observed in the neat liquid. These differences were caused by thermodynamic solvent effects. However, we conclude that aliphatic chain-chain interactions through palmitic and oleic acid moieties forming the MC of POP-OPO having a double chain length structure are not disturbed by solute-solvent interactions.

[Effect of remifentanil on intraoperative ECoG--a comparison with sevoflurane].

BACKGROUND: In surgeries for epilepsy, electrocorticography (ECoG) enables tailored resection of the epileptogenic brain and pharmacological stimulation should be employed in surgeries under general anesthesia. To identify the efficacy of continuous remifentanil in surgeries for epilepsy, ECoG findings with remifentanil and those with sevoflurane were compared. METHODS: Sixteen patients with intractable epilepsy were included with institutional ethics committee approval and informed consent. General anesthesia was induced and maintained with sevoflurane, remifentanil and rocuronium. After dural opening, ECoG recordings were obtained before stimulation, with sevoflurane-stimulation (ET-sevoflurane 2.5%) and with remifentanil-stimulation (0.7 microg x kg(-1) x min(-1) for 2 min followed by 0.35 microg x kg(-1) x min(-1)). RESULTS: In 11 of the 16 cases, activation was confirmed with remifentanil and numbers of spikes with remifentanil- and sevoflurane-stimulation were larger than those before stimulation. CONCLUSIONS: There have been some reports on bolus remifentanil on ECoG but not on its continuous infusion. This is the first report of the effect of remifentanil on ECoG as compared to sevoflurane. In this study, continuous infusion of remifentanil showed a stimulating effect on ECoG with the same potency as sevoflurane. Remifentanil may be used as an alternative to sevoflurane.

[Intraoperative neuronavigation system without rigid pin fixation].

OBJECT: Integration of neuronavigation into brain tumor surgery can improve the accuracy and precision of resection, but most neuronavigation systems require rigid pin fixation of the patient's head throughout the operation. We describe use of a noninvasive skull reference tool, which can replace rigid pin fixation in awake craniotomy and pediatric surgery, when standard pin fixation cannot be used. METHODS AND RESULTS: The skull reference tool (BrainLAB, Munich, Germany) is directly attached to the outer skull with a small self-tapping screw. Virtual scanning of the surface of the face and head achieves patient registration in seconds without requiring the use of fiducial markers or head fixation. This procedure improves patient comfort, cooperativeness, and compliance, resulting in better operating procedures. This skull reference tool is available for children younger than 3 years of age, in whom pin fixing is dangerous. Twelve patients underwent awake surgery and four pediatric patients younger than 3 years old underwent five procedures using this skull reference tool in our hospital between January 2005 and December 2008. The method of utilizing this skull reference tool was easy and sufficiently accurate in these patients. CONCLUSION: The use of this skull reference tool provides an accurate and comfortable method of frameless navigation in patients undergoing awake craniotomy and pediatric patients.

[Usefulness of human atrial natriuretic peptide in neurosurgical perioperative management].

PURPOSE: Intensive hypotension is an important technique in neurosurgical perioperative management. However, it could decrease urine volume, and induce fluid retention resulting in cardiac failure. We evaluated the efficacy of human atrial natriuretic peptide (hANP) on diuresis in a hypotensive condition. METHODS: In 245 patients undergoing neurosurgical operations under general anesthesia in our hospital, 26 patients demonstrated a urine volume less than 50 ml/h at 1 hour after the skin incision, despite receiving a large volume of intravenous fluid. In these 26 patients, we administered hANP (0.05 microg/kg/min) continuously, and evaluated the effect of hANP on diuresis in a hypotensive condition. RESULTS: After the administration of hANP, the urine volume increased significantly (p<0.01) from 28.7 to 229.4 (ml/h, mean). The heart rate increased from 66.6 to 71.7 (bpm, mean), whereas the systolic blood pressure decreased from 110.3 to 102.2 (mmHg, mean). The electrocardiogram did not change during the administration of hANP. CONCLUSIONS: Despite the hypotensive condition, hANP showed a strong diuretic effect in our study. In neurosurgical perioperative management, administration of hANP can be a useful tool for a fluid balance in the patient.

[Clinical features and significance of negative motor response in intraoperative language mapping during awake craniotomy].

The negative motor area and anterior and posterior language areas were localized by intraoperative electrical cortical stimulation under the awake condition to evaluate the clinical significance of these areas. Thirty-seven awake craniotomies with language mapping were performed in 36 patients with brain tumors. The negative motor area was determined in 17 cases, and the anterior and posterior language areas were found in 12 and 6 cases, respectively. The negative motor area was located in the precentral gyrus inferior to the orofacial motor area in 16 cases, and in the inferior frontal gyrus anterior to the orofacial motor area in one case. Both the negative motor area and the anterior language area were determined in 8 cases. Anterior language areas in these 8 cases were located anterior and/or inferior to the negative motor areas. The negative motor area is an easily determined, important landmark for intraoperative language mapping.

[Clinical use of remifentanil in neuroanesthesia].

BACKGROUND: Early detection of complications after craniotomies are important and remifentanil may be beneficial for that purpose because of the short and constant context-sensitive half time. To examine the efficacy of remifentanil in neuroanesthesia, we investigated hemodynamic properities and recovery from anesthsia in craniotomies. METHODS: Fifty patients undergoing scheduled neurosurgical procedures were included. Anesthesia was induced and maintained with propofol, vecuronium and fentanyl (group C, 25 cases) or remifentanil (group R, 25 cases). RESULTS: There were no diffirences between the groups in age, sex distribution, procedure, duration of anesthesia, and amount of bleeding. Total dose of propofol was lower in group R (3.4+/-1.0 mg x kg(-1) x hr(-1)) than group C (4.9+/-0.8) (P<0.001). Incidence of hemodynamic changes at tracheal intubation was higher in group C (P<0.01) and bradycardia (HR<45) was more frequent in group R (P<0.001). Recovery time was shorter in group R (12.7+/-4.7 min) than that in group C (20.7+/-7.3) (P<0.001). CONCLUSIONS: Remifentanil is suitable for neuroanesthesia because of the hemodynamic stability and quick recovery from anesthesia.