Retraction notice to "Recoveries of post-tetanic twitch and train-of-four responses after administration of vecuronium with different inhalation anaesthetics and neuroleptanaesthesia" [Br J Anaesth 1993; 70: 402-404].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Statistical analysis suggests that the data may be fabricated. Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings. Additionally, the Japanese Society of Anesthesiologists has recommended retraction of this article: http://www.anesth.or.jp/english/pdf/news20170925.pdf.

Retraction notice to "Relationship between post-tetanic twitch and single twitch response after administration of vecuronium" [Br J Anaesth 1993; 71: 443-444].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings.

Retraction notice to "Post-tetanic burst: a new monitoring method for intense neuromuscular block" [Br J Anaesth 1995; 74: 293-295].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Statistical analysis suggests that the data may be fabricated. Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings.

Retraction notice to "Post-tetanic count and single twitch height at the onset of reflex movement after administration of vecuronium under different types of anaesthesia" [Br J Anaesth 1994; 72: 688-690].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings.

Retraction notice to "Effect of tetanic stimulation on subsequent train-of-four responses at various levels of vecuronium-induced neuromuscular block" [Br J Anaesth 1994; 73: 416-417].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings.

Heme oxygenase-1 expression in oral squamous cell carcinoma as involved in lymph node metastasis.

Thirty-eight oral squamous cell carcinomas (SCCs) were semi-quantitatively analyzed by immunohistochemical staining, and the relation between heme oxygenase-1 (HO-1) expression and the clinical status were correlated. High immunostaining of HO-1 was detected in lymph node metastasis negative groups (P = 0.0018) and in well-differentiated SCCs (P = 0.0016). There were no significant correlations between heme oxygenase-1 expression and other factors, such as size of the tumor, staging, age and sex. These findings further support the proposition that high heme oxygenase-1 expression in oral SCCs can be useful in identifying patients at low risk of lymph node metastasis.

Inhaled nitric oxide improved the outcome of severe right ventricular failure caused by lipopolysaccharide administration.

OBJECTIVE: To evaluate the efficacy of nitric oxide (NO) inhalation against endotoxin-induced lung injury. DESIGN: Randomized prospective short-term study. SETTING: University school of Medicine Laboratory. INTERVENTIONS: Animal experiment (using 16 Japanese white rabbits). The animals inhaled NO at a concentration of 10 ppm. MEASUREMENTS AND RESULTS: The rabbits were randomly divided into the NO inhaling group (n = 7) and the control group (n = 9). Both groups received continuous infusion of 1200 mcg lipopolysaccharide (LPS) and the NO group inhaled 10 ppm NO during the LPS administration. In the control group, severe right ventricular (RV) failure was observed at 30-90 min of LPS infusion, and 4 of 9 animals died within 90 min of LPS infusion. In the NO group, none of the animals died and the early phase hemodynamic deterioration was milder than in the control group. But pulmonary gas exchange was not significantly different between the two groups throughout the study. At the end of the study there were no significant differences in any parameters of the surviving animals between the two groups. CONCLUSION: Although an improvement of pulmonary gas exchange was not demonstrated, NO inhalation (10 ppm) improved the outcome of severe RV failure caused by LPS infusion.

Chromatographic determination of free lidocaine and its active metabolites in plasma from patients under epidural anesthesia.

OBJECTIVE: We developed a simple and selective assay method for simultaneous determination of free lidocaine (LDC) and its active metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX) in plasma, by using high-performance liquid chromatography (HPLC). The method was applied to the plasma concentration monitoring in continuous epidural anesthesia with LDC. MATERIALS AND METHODS: Free fraction was separated from plasma by using an ultrafiltration technique. Free and total LDC, MEGX and GX in plasma were analyzed by HPLC equipped with ordinary octadecylsilyl silica (ODS) column and ultraviolet (UV) detector. PATIENTS: Five male patients with cancer who received epidural injection of 1.5% LDC for 5 hours in elective thoracic surgery, were enrolled to determine the plasma levels of total and free LDC, MEGX and GX. RESULTS AND DISCUSSION: The calibration curve for free LDC, MEGX and GX were linear at the concentration of 25 to 1,000 ng ml(-1) (r = 0.9998 - 0.9999). The recoveries for LDC, MEGX and GX from plasma water were ranged 73.2-89.1%. The coefficient variations for intra- and inter-day assay for LDC, MEGX and GX were less than 4.1%. The detection limit ofeach drug was 20 ng ml(-1). Plasma-free MEGX after 180 min epidural injection was higher than free LDC, even though the total concentration of MEGX was 4 times lower than that of LDC. The percentages of free fraction for LDC, MEGX and GX were 11.7, 48.5 and 78.3% after 5-hour epidural administration of LDC. Since the free fraction of MEGX and GX increases and exceeds the concentration of free LDC during continuous epidural anesthesia, accumulation of these toxic metabolites should be carefully monitored as well as LDC. CONCLUSION: The present method is a reliable technique and can be applied to monitoring free LDC, MEGX and GX, which provide us beneficial information as to the LDC metabolism and toxicity.

The formalin test: effects of formalin concentration and short-term halothane inhalation.

BACKGROUND AND OBJECTIVES: In order to evaluate the effects of formalin concentration and inhalational anesthetics in formalin tests, we injected 5 concentrations of formalin into awake and anesthetized rats and investigated their behavior and the c-fos immunoreactivity of their spinal cords. METHODS: Sixty adult male Sprague-Dawley rats were divided into 10 experimental groups. Each rat was either manually restrained or subdued through several minutes of 2% to 2.5% halothane inhalation, and then 1 of 5 concentrations of 0%, 5%, 10%, 27%, or 100% formalin (0%, 1.85%, 3.7%, 10%, or 37% formaldehyde solutions) was injected into its rear paw. Nociceptive behaviors were checked for 1 hour, 6 times for each 5-minute period. Two hours after the formalin injections, the rats were killed and c-fos immunoreactivity was measured. RESULTS: Typical responses were observed in the 5% and 10% formalin (1.85% and 3.7% formaldehyde) groups, and nociceptive behaviors were lower in the 27% and 100% formalin (10% and 37% formaldehyde) groups. The number of c-fos-positive cells increased as the formalin concentration increased. Halothane inhalation affected the results of both the behavior and the c-fos immunoreactivity, especially in the 10% formalin (3.7% formaldehyde) group. CONCLUSIONS: It is desirable to describe both formalin and formaldehyde concentrations simultaneously and to do formalin tests without inhalational anesthetics.

Plasma lidocaine, monoethylglycinexylidide, and glycinexylidide concentrations after epidural administration in geriatric patients.

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the effect of age on the pharmacokinetics of lidocaine after epidural administration. METHODS: Two percent lidocaine with epinephrine (5 microg/mL) was administered in two different age groups: an adult group (age 42 +/- 6 years, n = 10) and an elderly group (age 77 +/- 4 years, n = 10). Concentrations of lidocaine and its active metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX), were measured in plasma samples obtained after 15, 30, 45, 60, 90, 120, 150, and 180 minutes of administration using high-performance liquid chromatography with ultraviolet detection. RESULTS: No significant differences in plasma concentrations of lidocaine and its metabolites were observed between the two groups during the 3 hours of study. However, the elderly group showed significantly longer mean residence times (MRTs) and lower plasma clearance of lidocaine during the period compared with the adult group (P < .05). Plasma concentration ratios of MEGX/lidocaine were significantly lower in the elderly group after 2 hours of lidocaine administration (P < .05). CONCLUSIONS: The increase in plasma lidocaine concentration after epidural anesthesia in elderly patients was not as high as anticipated. However, the elderly patients showed longer MRTs, lower clearance, and lower ratios of MEGX/lidocaine than did the adult (middle-age) patients.

Plasma concentrations of lidocaine and its principal metabolites during continuous epidural infusion of lidocaine with or without epinephrine.

BACKGROUND AND OBJECTIVES: The purpose of this study was to evaluate the effect of epinephrine on the absorption of lidocaine and the accumulation of active metabolites of lidocaine during continuous epidural anesthesia. METHODS: Lidocaine was administered as an initial bolus of 5 mg/kg of 2% lidocaine solution followed by continuous infusion at 2.5 mg/kg/h. Patients in group I (n = 10) received lidocaine alone and patients in group II (n = 10) received lidocaine + epinephrine (5 pg/mL). Concentrations of lidocaine and its active metabolites, monoethylglycinexylidide (MEGX) and glycinexylidide (GX), were measured in plasma samples obtained after 15 minutes, 30 minutes, and 1, 2, and 3 hours of infusion using high-performance liquid chromatography with ultraviolet detection. RESULTS: Plasma lidocaine concentrations were higher in group I for the first 30 minutes; however, after 1 hour the levels were the same. Plasma MEGX and GX increased continuously in both groups. MEGX levels the were significantly higher in group I, but there was no significant difference in the sum of lidocaine + MEGX after 2 hours. There was no significant difference in GX levels between the two groups. CONCLUSIONS: With respect to continuous epidural administration, addition of epinephrine to lidocaine solutions is ineffective after 2 hours for reducing the potential for systemic toxicity, because the sum of the plasma concentrations of lidocaine and its principal active metabolite, MEGX, are unaffected.

Studies on radiopaque composites containing ZrO2-SiO2 fillers prepared by the sol-gel process.

Radiopacity can facilitate diagnostic observations adjacent to dental composites. To produce radiopaque SiO2-based fillers, ZrO2-SiO2 powders containing up to 45wt% ZrO2 were manufactured by the sol-gel process. The radiopacity of experimental composites containing Bis-GMA+TEGDMA+CQ+DMAEMA monomer mixture (25 wt%) and ZrO2-SiO2 fillers (75 wt%) was evaluated and compared to that of human enamel and two commercial composites with different radiopacity. It became evident that the radiopacity of the experimental composites increased linearly with zirconium content and could match that of the control materials, while the composite containing 15wt% ZrO2-85wt% SiO2 filler possessed radiopacity analogous to that of human enamel. It was demonstrated here that the radiopacity of the composites could be precisely controlled by adjusting the ZrO2 content in ZrO2-SiO2 fillers. These radiopacity-adjustable composites have the potential to be very useful filling materials by enabling dentists to accurately distinguish secondary caries adjacent to the composite restorations.

Combination of granisetron and droperidol in the prevention of nausea and vomiting after middle ear surgery.

STUDY OBJECTIVES: To evaluate the efficacy and safety of granisetron-droperidol combination for the prevention of postoperative nausea and vomiting (PONV) after middle ear surgery. DESIGN: Prospective, randomized, double-blind study. SETTING: University hospital. PATIENTS: 150 ASA physical status I patients (108 females, 42 males) scheduled for elective middle ear surgery. INTERVENTIONS: Patients received granisetron 40 micrograms/kg (n = 50), droperidol 20 micrograms/kg (n = 50), or granisetron 40 micrograms/kg plus droperidol 20 micrograms/kg (n = 50) intravenously immediately before induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: A standard general anesthetic technique and postoperative analgesia were used throughout the study. A complete response, defined as no PONV and no need for another rescue antiemetic, from 0 to 3 hours after anesthesia occurred in 78%, 56%, and 94% of patients who had received granisetron, droperidol, and granisetron plus droperidol, respectively. The corresponding incidence between 3 and 24 hours after anesthesia was 80%, 52% and 94%. Thus, a complete response within the first 24-hour postanesthetic period was greater in patients receiving granisetron-droperidol combination than in those receiving granisetron alone or droperidol alone (p < 0.05). No clinically adverse events were observed in any of the groups. CONCLUSIONS: A combination of granisetron and droperidol is more effective than droperidol or granisetron alone for the prevention of PONV after middle ear surgery.

Effects of oral clonidine premedication on side effects of intravenous ketamine anesthesia: a randomized, double-blind, placebo-controlled study.

STUDY OBJECTIVE: To determine the effects of oral clonidine premedication on hemodynamic changes during the entire course of ketamine anesthesia and incidence of postoperative adverse reactions. DESIGN: Randomized, prospective, double-blind, placebo-controlled study. SETTING: Department of Anesthesiology, University of Tsukuba Hospital, Ibaraki, Japan. PATIENTS: 39 ASA physical status I and II patients undergoing superficial surgeries. INTERVENTIONS: Placebo, clonidine 2.5 micrograms/kg, and clonidine 5 micrograms/kg groups received respective doses of oral clonidine 90 minutes prior to surgery. Anesthesia was induced with ketamine 2 mg/kg intravenously (i.v.), trachea was intubated, and anesthesia was maintained with 67% nitrous oxide, oxygen, and supplemental ketamine (1 mg/kg) when systolic blood pressure and heart rate (HR) exceeded 180 mmHg and 100 bpm, respectively. MEASUREMENTS AND MAIN RESULTS: In the clonidine 2.5 micrograms/kg group, HR response to tracheal intubation was significantly less, while in the clonidine 5 micrograms/kg group both mean arterial pressure and HR responses were significantly suppressed, compared with the placebo group. Intraoperative coefficients of variations of HR were significantly less in both clonidine groups than the placebo group. Incidence of nightmare and degree of salivation were significantly less in the clonidine 5 micrograms/kg group than in the placebo group. CONCLUSION: Oral clonidine 2.5 micrograms/kg and clonidine 5 micrograms/kg attenuates cardiostimulatory effects, while clonidine 5 micrograms/kg was associated with reduced incidence and severity of nightmare and salivation attributable to i.v. ketamine.

Hardness and fracture toughness of commercial core composite resins.

One important mechanical property of core composite resins is fracture toughness, KIC, which expresses serviceability in the oral cavity, such as the resistance to marginal fracture. KIC values of eight commercial core composite resins were examined by the single-edge notched-beam (S.E.N.B.) method. Two composites containing about 80 wt% Si3N4 fillers exhibited both the highest KIC value of around 2.0 MN.m-3/2 and the highest hardness value. The other six composites containing 66 to 86 wt% SiO2-based fillers had KIC values of around 1.2 to 2.0 MN.m-3/2, and there was a tendency toward higher KIC values as hardness increased. It was speculated that the clinical acceptability of core composite resins could be broadened, if dental clinicians selected composites with higher KIC values.

[Preparation and clinical evaluation of orally-disintegrating clonidine hydrochloride tablets for preanesthetic medication].

Orally-disintegrating tablets of clonidine hydrochloride, an alpha 2-adrenergic agonist, were prepared by the method of drying an aqueous suspension. The suspension was prepared using powdered lactose, and the composition ratio was 2:1 (powdered lactose: 0.048% clonidine hydrochloride solution). The suspension was dried under 4 +/- 1 degrees C (72 +/- 15% R.H.). We obtained tablets containing clonidine hydrochloride (40 micrograms/tablet). Physical properties of the tablets were as follows: hardness was 4.0 kgf, and disintegration time was 41.7 s (in vitro). In the clinical use, 8 patients, aged 1-2 year and weighing 9-11 kg, received approximately 4 micrograms/kg body weight as clonidine hydrochloride. The tablet was administered 90 min before entering the operating room. All patients were willing to accept the tablet. The quality of separation from parents, sedation and a mask acceptance were excellent on all patients. These results suggest that the orally-disintegrating tablet of clonidine hydrochloride was useful in a clinical situation for the preanesthetic medication of pediatric patients aged 1-2 year.

[The effect of high frequency jet ventilation on intracranial pressure in the patients with severe head injury].

The effect of high frequency jet ventilation (HFJV) on intracranial pressure (ICP) in the series of seven patients with severe head injury was studied. These patients received mechanical ventilation for respiratory failure accompanied with neural damage or circulatory shock and for ICP control by decreasing PaCO2. ICP was measured continuously by subarachnoid catheter method connected to Gould P-50 strain-gage transducer and controlled by hyperventilation and/or osmotic diuretics during acute phase. Arterial pressure, central venous pressure and intratracheal pressure were measured continuously in the same way. Arterial blood gases were analysed by BG-I of Technicon Co. Ltd. At the weaning from respirator, two methods were applied. One was conventional IMV (with PEEP) and/or CPAP by using IMV mode of Servo 900 respirator or T-piece together with PEEP valve and another was new-fashioned HFJV. Mean intratracheal pressure (mPit) was fixed at 0 mmHg (control value), 5, 10 and 15mmHg in both methods by adjusting PEEP valve or driving pressure of HFJV. The result is that in the same patients ICP was significantly lower during HFJV than IMV/CPAP when mPit was 5 and 10mmHg. Only three cases having been studied at 15mmHg of mPit because circulatory condition would not permit it, significant difference of ICP between HFJV and IMV/CPAP was not detected. PaCO2, being suspected to be the cause of lower ICP of HFJV group, was studied too. But blood gas analysis showed no significant difference neither PaCO2 nor PaO2. The fluctuation of CVP reflecting the change of intrathracic pressure was smaller in HFJV group than in IMV/CPAP group.(ABSTRACT TRUNCATED AT 250 WORDS)

[Some practical problems and several methodological trials in continuous intracranial pressure monitoring].

The continuous intracranial pressure monitoring has been widely applied in intensive or critical care, but there are various kinds of methods for its monitoring at present. One hundred and forty-one cases mostly with severe head injury were subject to the intracranial pressure recordings in the critical care ward in Department of Emergency Medicine, University of Tokyo Hospital, from October, 1980 through May, 1983, and in Neurosurgical Unit, Showa General Hospital, in April and May, 1984. The authors made several methodological trials for the monitorings in them and compared with one another from the aspect of clinical practice. The subarachnoid catheter was inserted into the subarachnoid or sometimes into the subdural spaces by way of the burr hole in 112 cases and proved not to demonstrate in some cases the intracranial pressure waves clearly due to so called damping phenomenon but to indicate the reliable values, or trustworthy mean pressures in all the cases except for impending brain dead patients with swollen hemispheres and least cerebrospinal fluid remained in intracranial subarachnoid spaces. The ventricular fluid pressure was monitored in nine cases and was most dependable as well as the subarachnoid pressure. The ventricular cannulation and its maintenance were, however, difficult when the ventricles were compressed or deviated, which were often experienced in acute severe head injury and also in impending brain death just because of the same above mentioned reasons. These demerits were attempted to be conqured with epidural pressure monitorings such as the fiberoptic sensor (Ladd) in 17 cases, the intracranial catheter tip pressure transducer (Gaeltec) in nine cases and the sensor of bioimplantable polymer (Plastimed) in three cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Ketamine infusion therapy for refractory neuralgia in spinal disease: report of two cases].

We report two cases of refractory pain in a spinal disease. One case was a 60-year-old male who presented intractable pain in bilateral upper extremities after anterior fusion (C5/6, 6/7) for cervical spondylosis. The other was a 63-year-old female who also had intractable pain in the left anterio-lateral chest wall with no remarkable past history. Both cases were refractory to nonsteroidal anti-inflammatory drugs (NSAIDs) or minor tranquilizer or local anesthesia with bupivacaine. However, their pain was significantly relieved by the intravenous administration of a test dose (5mg) of ketamine which is a noncompetitive blocker of N-methyl-D-aspartate (NMDA) receptors. As for case 1, the effect of the injection of the test dose lasted, so continuing infusion therapy of ketamine was cancelled. In case 2, recurrence of the pain was recognized gradually. She underwent continuing infusion therapy of 2mg/kg of ketamine, and it brought about continued pain relief. We conclude that ketamine infusion therapy should also be considered for therapy of refractory neuralgia in spinal disease.