Dental findings and intravenous sedation in a patient with Potocki-Lupski syndrome: A case report

AIMS

Potocki-Lupski syndrome (PTLS), which is caused by the partial duplication of the short arm of autosome 17, is characterized by feeding difficulties associated with muscle hypotonia and dysphagia in infancy, followed by growth retardation and low body weight in later stages. Speech and motor developmental disorders are observed in childhood, accompanied by autism spectrum disorders in several cases. Other disorders include dental and skeletal abnormalities, and associated sleep apnea. Herein, we describe the first case of dental evaluation and treatment under intravenous sedation in a patient with PTLS.

METHODS

A 13-year-old boy with PTLS and intellectual disability was referred for the treatment of dental caries. Routine intraoral examination and dental treatment were not feasible. As the patient had no muscle hypotonia, dysphagia, or severe growth delay, intraoral examination and dental treatment were successfully performed under intravenous sedation. No incidence of intraoral airway obstruction or aspiration was reported. The patient was followed-up post-operatively.

CONCLUSION

PTLS, a newly identified syndrome, is associated with cardiovascular abnormalities, dysphagia, failure to thrive, and sleep apnea, which are potential risk factors for sedation. This case report highlights the importance of facial and oral findings in determining the risks of difficulties in airway management.

Factors associated with transient bradycardia during local anesthesia administration to the oral cavity under intravenous sedation: A retrospective cohort study

Background/purpose

The possibility of triggering the trigeminocardiac reflex (TCR) during oral surgery is considerably lower than that during other surgeries. A reduced heart rate (HR) of ≥20% from baseline is usually considered a diagnostical criterion for the TCR. Our automated anesthesia charting system often revealed cases of slight transient HR decrease during sedation. We aimed to explore its incidence and associated factors during local anesthesia administration under intravenous sedation.

Materials and methods

This study analyzed the data of 2636 cases that received infiltration anesthesia under intravenous sedation from 2008 to 2010 and had vital signs recorded using an automated anesthesia charting system. Especially, data concerning the average HR before anesthesia and the minimum HR between the initiation and end of anesthesia from anesthetic records were extracted. Moreover, data regarding patients' medical history and unusual reactions during dental treatment were collected. Multivariate logistic regression analysis was performed to identify factors associated with transient bradycardia (TB).

Results

TB occurred in 472 patients (17.9%); no patient developed hypotension or any associated symptoms, suggesting that intravenous sedation was effective in stabilizing vital signs. The factors associated with TB were younger age, gag reflex, and allergy to local anesthetics. There were no differences in sex, patient history, or dose of sedatives between patients with TB and those without TB.

Conclusion

The incidence of TB during infiltration anesthesia under sedation was found to be higher than that previously reported. Additionally, young age and gag reflex were identified as factors associated with bradycardia development.

Combined Use of a Gum Elastic Bougie and Video Laryngoscopy for Intubating a Patient With an Unexpected Laryngeal Papilloma

This is a case report of a 75-year-old man scheduled for apical resection and cystectomy of odontogenic cysts involving both maxillary central incisors who presented with a previously unknown laryngeal mass that was discovered prior to intubation. Following induction and easy mask ventilation, direct laryngoscopy revealed a large mass on the right side of the glottis that impeded passage of a standard oral endotracheal tube. Successful atraumatic intubation was performed with the combination of a video laryngoscope (King Vision, Ambu Inc, Ballerup, Denmark) and a gum elastic bougie (GEB). Although a GEB may not be used routinely for tracheal intubation, it facilitated smooth advancement of the endotracheal tube without damaging the laryngeal mass when used in combination with video laryngoscopy.

Oral management of a patient with down syndrome and agammaglobulinemia: a case report

Background

Down syndrome is characterized by a variety of dysmorphic features and congenital malformations, such as congenital heart disease, gastrointestinal disease, and other conditions like leukemia and autoimmune disorders. Patients with Down syndrome are highly prone to respiratory tract infections, which might be fatal to them. However, there are only few available data on patients diagnosed with Down syndrome and agammaglobulinemia. In this report, we describe a case of successful prevention of post-dental treatment complications (e.g., pneumonia and other bacterial infections) in a patient with Down syndrome and agammaglobulinemia.

Case presentation

A 43-year-old man with Down syndrome, untreated agammaglobulinemia, and a history of recurrent pneumonia, was referred to our clinic for tooth mobility. To reduce the risk of post-operative infections, gammaglobulin treatment and prophylactic administration of antibiotics was scheduled before the dental procedure. Furthermore, the dental treatment, which included a filling and extractions, was conducted under general anesthesia and with the supervision of a hematologist. The dental procedures were successfully performed without any post-operative infection, and the patient is undergoing follow-up care.

Conclusions

The purpose of this case report was to recommend a close liaison between physicians and dentists who may encounter a similar case, and to emphasize the importance of improving oral health of immunodeficient patients to prevent infections caused by oral microbial flora.

Dorsal Root Ganglia Homeobox downregulation in primary sensory neurons contributes to neuropathic pain in rats

Transcriptional changes in primary sensory neurons are involved in initiation and maintenance of neuropathic pain. However, the transcription factors in primary sensory neurons responsible for neuropathic pain are not fully understood. Dorsal Root Ganglia Homeobox (DRGX) is a paired-like homeodomain transcription factor necessary for the development of nociceptive primary sensory neurons during the early postnatal period. However, roles for DRGX after development are largely unknown. Here, we report that DRGX downregulation in primary sensory neurons as a result of post-developmental nerve injury contributes to neuropathic pain in rats. DRGX expression was decreased in nuclei of small and medium primary sensory neurons after spinal nerve ligation. DRGX downregulation by transduction of a short hairpin RNA with an adeno-associated viral vector induced mechanical allodynia and thermal hyperalgesia. In contrast, DRGX overexpression in primary sensory neurons suppressed neuropathic pain. DRGX regulated matrix metalloproteinase-9 (MMP-9) and prostaglandin E receptor 2 mRNA expression in the DRG. MMP-9 inhibitor attenuated DRGX downregulation-induced pain. These results suggest that DRGX downregulation after development contributes to neuropathic pain through transcriptional modulation of pain-related genes in primary sensory neurons.

Interfacial interaction of anesthetic lidocaine and mesoporous silica nanoparticles in aqueous solutions and its release properties

Lidocaine has been used as a local anesthetic by injection. The controlled release of lidocaine loaded into nanospheres is necessary to reduce the onset time of the anesthetic effect or increase the anesthetic analgesia duration. In this study, mesoporous silica nanoparticles (MSNs) with a large specific surface area were prepared by a sol-gel method, and the interfacial interaction between MSNs and lidocaine positively charged in aqueous solutions at different concentrations was investigated by adsorption tests, Fourier-transformed infrared spectroscopy, thermogravimetry-differential thermal analysis, and Brunauer-Emmett-Teller (BET) measurements. The electrostatic interaction between Si-OH on MSNs and lidocaine-NH⁺ was of importance for the adsorption phenomenon in aqueous solutions, indicating the monolayer adsorption of lidocaine. BET measurements also supported the decrease of pore volumes, and the hysteresis loop of the isotherm curve was not closed since the condensation of lidocaine in the mesopores formed micropores of less than 1.5 nm in size. The release profiles in phosphate buffered saline containing calcium and magnesium ions showed a rapid and higher release of lidocaine compared with that in phosphate buffered saline without divalent cations. The released lidocaine concentrations were sufficient for the expression of the anesthetic effect in dental anesthesia.

Alternating Current Iontophoresis for Control of Postoperative Pain

Control of early postoperative pain entails the use of various medications including acetaminophen, nonsteroidal anti-inflammatory drugs, selective cyclooxygenase-2 inhibitors, tramadol, and opioids. However, these medications should be carefully administered in patients with aspirin-exacerbated respiratory disease because some medications may trigger adverse reactions after maxillofacial surgeries. The goal of postoperative pain control in patients with aspirin-exacerbated respiratory disease is to eliminate pain without complications. Local anesthesia is an efficient tool for the control of postoperative pain after maxillofacial surgeries. We utilized a transdermal drug delivery system, iontophoresis by alternating current, in order to develop an alternative technique for administering local anesthetic to control postoperative pain in 2 patients with aspirin-exacerbated respiratory disease. A visual analogue scale was used to objectively measure the severity of pain. A 55-year-old woman who underwent mandibular wisdom tooth extraction and an 18-year-old woman who underwent sagittal split ramus osteotomy of the mandible both complained of pain multiple times. After application of iontophoresis, the visual analogue scale score was reduced to zero and postoperative pain could be controlled. There were no adverse events such as bronchospasm or skin irritation after the application of iontophoresis by alternating current.

Difficult Nasal Intubation Using Airway Scope® for a Child With Large Tumor

We report a case of difficult nasal intubation utilizing a Pentax-Airway scope^® AWS-100. A 4-month-old female with a rapidly growing melanotic neuroectodermal tumor was scheduled for resection under general anesthesia. The tumor was a large rubbery mass located in the middle of the mandible. For nasal intubation using the AWS, guidance of the tube toward the glottis was attempted using pediatric Magill forceps. Although we could hold the tube with the Magill forceps, it was difficult to insert the tube into the trachea due to the limited space in her hypopharynx. We then used a standard laryngoscope with a Miller straight blade for direct visual laryngoscopy and successfully intubated the patient with the aid of the pediatric Magill forceps. We often experience difficulty navigating a nasal endotracheal tube toward the glottis even when a clear glottic view is obtained with video laryngoscopes, especially in children with a small oropharyngeal space. However, some reports have been shown that video laryngoscopes are useful for intubation of the difficult airway and causes less stress to the upper airway than direct visual laryngoscopy. Video laryngoscopy can be an excellent way to provide nasal intubation in some but not all children.

The Effect of Adding Midazolam to Propofol Intravenous Sedation to Suppress Gag Reflex During Dental Treatment

We retrospectively investigated the efficacy and safety of propofol administration alone and in combination with midazolam for gag reflex suppression during dental treatment under intravenous sedation. We included 56 patients with an overactive gag reflex who were to undergo dental treatment under intravenous sedation. They were divided into propofol (P group, n = 22) and midazolam with propofol (MP group, n = 34) groups. The P group received propofol alone, while the MP group received midazolam (0.04 mg/kg) prior to target-controlled infusion (TCI) of propofol (titrated for adequate sedation). The patients' anesthetic records were evaluated for vital sign changes, adverse cardiovascular or respiratory event frequency, the number of forced treatment interruptions, and the TCI-predicted cerebral propofol concentration at gag reflex suppression (posterior tongue stimulation with a dental mirror). No significant differences were observed between the 2 groups preoperatively. There were no cases of forced interruptions or significant respiratory compromise in either group. Cardiovascular adverse event frequency was lower in the MP group than in the P group (all p < .05). Our results suggest that propofol, when combined with midazolam, minimized cardiovascular effects compared with propofol alone when used to suppress the gag reflex in patients during dental treatment under intravenous sedation.

Perioperative Management of a Patient With Cornelia de Lange Syndrome and Tetralogy of Fallot

This is a case report of a 21-year-old male patient with Cornelia de Lange syndrome (CdL) and unrepaired tetralogy of Fallot scheduled for dental treatment under general anesthesia. Anticipated dental care consisted of restorative treatment and extractions. Surgical correction of the patient's congenital cardiac abnormalities had not occurred by the time of dental treatment. As such, the developed anesthetic plan included the following goals: prevention of any anoxic episodes or spell and preparation for difficult airway management due to micrognathia secondary to CdL. To help ensure adequacy of oxygenation during induction, the normal anesthetic face mask was specially modified with a hole to permit use of the fiberoptic scope during induction and intubation. With preoperative consultation involving a cardiologist as well as the use of the modified mask, general anesthesia was safely administered without any complications.

New method for postoperative pain relief using a combination of noxious and non-noxious stimuli after impacted wisdom tooth extraction

Although in clinical dentistry the major method used for pain relief is oral administration of analgesics, alternative methods are available, such as transcutaneous electrical nerve stimulation (TENS), acupuncture, vibration and conditioned pain modulation (CPM), formerly termed diffuse noxious inhibitory control. The aim of the present study was to investigate the combined effects of non-noxious (TENS) and noxious (CPM) stimuli on postoperative pain after extraction of an impacted wisdom tooth. The study involved 44 patients who were scheduled to undergo impacted wisdom tooth extraction. The patients were randomly allocated into four groups: noxious stimuli, non-noxious stimuli, combined noxious and non-noxious stimuli, and a sham group. On the day after tooth extraction, stimulation procedures for pain relief were performed and changes in the level of perceived pain were scored using a visual analog scale (VAS). The combination of non-noxious and noxious stimuli decreased the VAS scores by 63.7%, indicating a more potent analgesic effect than that in the non-noxious, noxious, and sham groups. This method of analgesia using a combination of non-noxious and noxious stimuli can be applied to patients who are unable to tolerate analgesics, such as those with allergy, hypersensitivity or digestive disorders, and those who are pregnant.

Treatment of oral cancers during pregnancy: a case-based discussion

Background

Malignancies occur in approximately 1:1000 pregnancies; the most common being breast (46%) and hematological (18%) malignancies. Oral cancers account for only 2% of all cancers in pregnant women, and there are no standard guidelines for the treatment of oral cancer during pregnancy.

Methods

Between 2007 and 2014, our department managed 1109 patients with oral cancers; four (0.4%) had tongue carcinomas during pregnancy. These cases were retrospectively reviewed.

Results

The four women were aged 29–39 (median 32.5) years. Two underwent partial glossectomy at 39 and 40 weeks’ gestation, respectively, one received radiotherapy at 17 weeks’ gestation, and one underwent supraomohyoid neck dissection and hemi-glossectomy with a forearm flap reconstruction.

Conclusion

In addition to tumor factors, the wishes of the patient and her family, gestational age, and fetal and maternal conditions are important factors in deciding on a treatment protocol. Moreover, treatment decisions require multidisciplinary approach.

Oral and maxillofacial surgery in patients undergoing dialysis for advanced renal disease: report of five cases

BACKGROUND

Perioperativemanagement of hemodialysis patients involves many difficulties. High mortality rate and circulatory or respiratory complications in these patients were reported. However, in such reports, there is no concrete information of perioperative management in hemodialysis patients to prevent surgical complications and successful outcomes.

CASE PRESENTATION

We retrospectively reviewed the cases of 5 hemodialysis patients who underwent oral surgery under general anesthesia between January 2005 and December 2017. Primary disease was oral squamous cell carcinoma (SCC) in 4 patients and mandibular ameloblastoma in 1 patient. Partial resection was performed in 2 cases, neck dissection in 1 case. Two cases underwent surgery including vascularized reconstruction. The patients were dialyzed the day before and after surgery for the control of fluid and electrolyte status. Patients received intraoperative and postoperative intravenous infusion of potassium-free solution at 20-40 mL/h. Erythropoiesis-stimulating agents (ESAs) were used on the day of hemodialysis during hospitalization. Nafamostat mesilate as an anticoagulant during hemodialysis were used from postoperative day (POD)1 to 7. From POD 1 to 10, cephalosporin as prophylactic antibiotics is adjusted to quarter from half the initial dose. The resuming time of oral intake was similar to that of other oral surgery patients without kidney disease. The daily intake limits of protein, salt and liquid were managed during hospitalization and no cases suffered from malnutrition. No cardiorespiratory complications occurred during the perioperative period. In a case of vascularized osteocutaneous scapular flap reconstruction, grafted scapular bone survived and scapular cutaneous flap necrotized. Necrotic tissue was debrided and split thickness skin was successfully used to cover the grafted scapular bone.

CONCLUSIONS

Postoperative better result could be achieved if adequate perioperative management specific to hemodialysis patients is carried out. Vascularized flap reconstruction at oral and maxillofacial region in hemodialysis patients is beneficial treatment. Even if the first flap has wound complication secondary flap reconstruction is success and aesthetically better results could be achieved by the strict wound management and debridement.

Methemoglobinemia should be suspected when oxygen saturation apparently decreases after prilocaine infiltration during intravenous sedation

During intravenous sedation, a decrease in SpO2 is usually the result of respiratory failure. However, we experienced a case with SpO2 decrease that was caused by methemoglobinemia in prilocaine infiltration anesthesia during sedation. This indicates that methemoglobinemia should be considered if low SpO2 is sustained unrelated to sedation level.

Hypoesthesia associated with mandibular movement after sagittal split ramus osteotomy

PURPOSE

This retrospective study investigated the relationship between the degree of neurosensory disturbance (NSD) and mandibular movement distance after sagittal split ramus osteotomy (SSRO) and assessed sensory recovery.

METHODS

Lower lip hypoesthesia was evaluated at 1 week, 1 month, and 2 months after SSRO in 38 patients categorized according to the distance of mandibular movement: S group (0-7 mm; n = 17, 4 males and 13 females) and L group (7-14 mm; n = 21, 7 males, 14 females). Symptoms were evaluated by visual analog scale (VAS), tactile-threshold (SW) test, static 2-point discrimination (s-2PD) test, and current perception threshold (CPT) test.

RESULTS

The two groups did not differ significantly in gender and age. The Aβ fiber results of the CPT test differed significantly between the groups at 1 week and 1 month postsurgery (P < 0.05). There were no significant differences between the groups throughout the period in terms of VAS, SW, s-2PD, Aδ fiber, and C fiber of CPT.

CONCLUSIONS

Post-SSRO, the incidence of NSD in terms of tactile sensation may be greater in the L group early postoperatively. This may assist surgeons in explaining postoperative hypoesthesia to patients preoperatively.

Modafinil enhances alerting-related brain activity in attention networks

RATIONALE

Modafinil is a wake-promoting agent and has been reported to be effective in improving attention in patients with attentional disturbance. However, neural substrates underlying the modafinil effects on attention are not fully understood.

OBJECTIVES

We employed a functional magnetic resonance imaging (fMRI) study with the attention network test (ANT) task in healthy adults and examined which networks of attention are mainly affected by modafinil and which neural substrates are responsible for the drug effects.

METHODS

We used a randomized placebo-controlled within-subjects cross-over design. Twenty-three healthy adults participated in two series of an fMRI study, taking either a placebo or modafinil. The participants performed the ANT task, which is designed to measure three distinct attentional networks, alerting, orienting, and executive control, during the fMRI scanning. The effects of modafinil on behavioral performance and regional brain activity were analyzed.

RESULTS

We found that modafinil enhanced alerting performance and showed greater alerting network activity in the left middle and inferior occipital gyri as compared with the placebo. The brain activations in the occipital regions were positively correlated with alerting performance.

CONCLUSIONS

Modafinil enhanced alerting performance and increased activation in the occipital lobe in the alerting network possibly relevant to noradrenergic activity during the ANT task. The present study may provide a rationale for the treatment of patients with distinct symptoms of impaired attention.

<Original Article>Drug delivery and transmission of lidocaine using iontophoresis in combination with direct and alternating currents

The present study investigates how effectively lidocaine ions are transported across a cellophane membrane through the application of either a direct current (DC) or alternating current (AC). The cellophane membrane was set on a parallelplate- type acrylic cell with platinum electrodes at both ends, filled with a donor cell of a 1 % aqueous solution of lidocaine and a receptor cell with distilled water. Lidocaine concentrations were measured for 60 min while the following voltages were applied, with changes every 10 min: 3 V DC and 7.5 V sine wave AC; frequency at 1 kHz. As a result, lidocaine concentrations in the receptor cell increased in a time-dependent manner. Significant increases in lidocaine concentrations were observed in groups where the voltage combination consisted of DC 30 min/AC 30 min, DC 50 min/AC 10 min, DC 60 min and AC 10 min/DC 50 min, compared with the passive diffusion group or in groups where voltage application was performed for 20, 30 , 40, 50 and 60 min. Significant increases were also observed in groups where the voltage combination consisted of A C 6 0 min, D C 10 min/AC 5 0 min, AC 3 0 min/ DC 30 min and AC 50 min/DC 10 min, compared with the passive diffusion group or in groups where voltage application was performed for 40, 50 and 60 min. These results suggest that lidocaine was delivered more rapidly with DC than with AC, and that its ions are transported faster when voltage is switched from DC to AC than from AC to DC, which is presumably due to the contribution of electrorepulsion by DC voltage application and the vibration energy infiltration mechanism owning to AC. Iontophoresis in combination with DC and AC was found to enable highly efficient drug delivery that shares the benefits of both forms of current application.

Correlation Between Body Movements and Salivary Secretion During Sedation

During dental sedation, control of the cough reflex is crucial for a safe and smooth procedure. Accumulated saliva is one of the predisposing factors for coughing. Body movements during dental sedation appear to enhance salivation. Therefore, the aim of this study was to investigate the difference in salivary secretion between the with-movements state and the without-movements state during sedation. Salivary weight for 1 min was measured 3 times in 27 patients with intellectual disability during dental treatment under deep sedation with midazolam and propofol. The observed variables were body movements, bispectral index (BIS), and predicted propofol effect-site concentration. A total of 81 measurements were classified into the with-movements state (n = 39; ie, measurements during which body movements were observed) or the without-movements state (n = 42; ie, measurements during which no body movements were observed). The median salivary weight was significantly smaller in the without-movements state compared with the with-movements state (0.03 vs 0.11 g, P < .0001). The BIS was significantly lower in the without-movements state. There was no significant difference in the predicted propofol effect-site concentration between the 2 states. Significant correlation was observed between salivary weight and BIS in the with-movements state (r = 0.44, P = .004). The findings indicate that salivary secretion decreased according to deep sedation. Furthermore, immobility also reduced salivary secretion. We concluded that one reason that immobility is beneficial is because of the resulting decreased salivary secretion during dental treatment under deep sedation.

An analysis of green discoloration of urine caused by propofol infusion

BACKGROUND

Propofol is a short-acting, intravenous sedative-hypnotic agent that is widely used for the induction and maintenance of general anesthesia and sedation. An uncommon adverse effect of propofol is green discoloration of the urine, which has been reported not only under general anesthesia but also with sedation. Although it is assumed that the phenolic derivatives of propofol can cause green discoloration of the urine, the actual origin remains unknown. The aim of this report was to identify the origin of the green discoloration of the urine using liquid chromatography-mass spectrometry (LC-MS).

CLINICAL FEATURES

The patient, a 51-year-old man, was scheduled for his oral surgery under general anesthesia using propofol. Postoperatively, the color of his urine was observed to be green. We compared and analyzed both the green urine and the normal urine using LC-MS.

CONCLUSION

We experienced a case of a patient with green discoloration of the urine after general anesthesia using propofol. Although LC-MS analysis showed 2 unique peaks in the green urine at 490 and 590 nm, obvious causes were not revealed.

NGF is Induced by Lidocaine in Human Skin Fibroblast Cells In Vitro

We incubated skin fibroblasts with various concentrations of lidocaine for 3, 24, and 48 hours and found that the NGF mRNA expression levels significantly increased after incubation for 3 hours, indicating that the incubation for 3 hours activated the signaling that induce the NGF mRNA expression.

Enhancement of Analgesic Effect by Combination of Non-Noxious Stimulation and Noxious Stimulation in Humans

The aim of the this study was to investigate the combined effects of heterosegmental non-noxious and noxious stimulation on electrically induced tooth pain. The late component of somatosensory-evoked potentials (SEP), induced by electrical tooth stimulation and pain intensity, were examined under electrical stimulation to forearms. Noxious, non-noxious, and combined non-noxious and noxious electrical stimulation were applied to median nerves on the forearms. Four experimental sessions (ie, control session, combined non-noxious and noxious stimulation session, non-noxious stimulation session, and noxious stimulation session were performed for each subject at each 10-minute interval for 30 minutes. The amplitudes of the SEP and VAS scores in the combined stimulation session decreased significantly compared with those in the control session and the reduction rates were 51.1% (13.4 μV) and 41.0% (23.5 mm), respectively. These results show that the combined stimulation has a more potent analgesic effect than that of either the non-noxious or the noxious stimulation. It is suggested that a potent analgesia was produced by an activated central mechanism, including endogenous opioid and descending pain inhibitory systems due to combined non-noxious and noxious stimulation.

Modafinil augments brain activation associated with reward anticipation in the nucleus accumbens

RATIONALE

The nucleus accumbens (NAc) works as a key brain structure of the reward system, in which reward-related neural activity is well correlated with dopamine release from mesolimbic dopaminergic neurons.

OBJECTIVES

Since modafinil can modulate dopaminergic transmission through re-uptake inhibition of dopamine, we investigated whether modafinil affects the reward-related brain activity in the NAc in healthy subjects.

METHODS

Twenty healthy participants underwent two series of functional magnetic resonance imaging while performing monetary incentive delay task in which they were cued to anticipate and respond to a rapidly presented target to gain or avoid losing varying amounts of money, under modafinil or placebo condition. Blood oxygenation-level dependent (BOLD) activation signals during gain and loss anticipations were analyzed in the NAc as an a priori region of interest as well as the whole brain.

RESULTS

Modafinil significantly changed subjective feelings toward positive ones. The activation of BOLD signals was observed during gain anticipation under the placebo and modafinil conditions in the left and bilateral NAc, respectively. The modafinil condition showed significantly higher BOLD signal change at the highest gain (+¥500) cue compared to the placebo condition.

CONCLUSIONS

The present study showed that modafinil affects reward processing in the NAc in healthy subjects through enhancing more positive anticipation, and it may provide a basis for the use of this drug for treating anhedonia observed in psychiatric disorders.

Evaluation of calcium alginate gel as electrode material for alternating current iontophoresis of lidocaine using excised rat skin

Iontophoresis (IOP) is a noninvasive method of delivering medication transcutaneously through the skin. The electrodes used in this method should tightly fit to rough and irregular surfaces and be biologically safe, easy to handle and prepare, and cost-effective. To satisfy these requirements, calcium alginate gel can be a candidate electrode for IOP. Using calcium alginate gel electrodes, we examined whether lidocaine can be effectively transported across an excised rat skin by squarewave alternating current (AC) application. A squarewave AC with either a 70% or 80% duty cycle was continuously applied to 0.5% calcium alginate gel electrodes containing 10% lidocaine at 10 V and 1 kHz for 60 min. Lidocaine concentration was measured using a spectrophotometer and the temperature of the gel was determined. The lidocaine concentrations for AC-IOP at the 70% and 80% duty cycles were significantly higher than that without AC-IOP. Furthermore, the group with the 80% duty cycle showed higher lidocaine concentrations than the group with the 70% duty cycle. The temperatures of all the groups were lower than 28 °C throughout the procedure. In conclusion, the calcium alginate gel can be used as a possible matrix for IOP electrodes.

Efficacy of lidocaine lontophoresis using either alternating or direct current in hairless rats

The aim of this study was to determine transport of lidocaine ions through a hairless rat skin in vivo and to compare the efficacy of alternating current (AC) with that of direct current (DC) iontophoresis (IOP). We measured the concentration of lidocaine transported through a cellophane membrane or a hairless rat dorsal skin applying either AC-IOP or DC-IOP. The results revealed that lidocaine concentration increased in a time-dependent manner in vitro in both DC-IOP and AC-IOP. However, the in vivo study showed different tendencies in lidocaine concentration. In the DCIOP group, lidocaine concentration reached its maximum 20 min after current application and then decreased rapidly; the AC-IOP group showed an increase in lidocaine concentration in a time-dependent manner. There were no side effects such as electrical burns in the rats. In conclusion, AC can be applied for long periods and DC for short periods, or their application time can be appropriately scheduled. Our study also suggests the mechanism by which voltage waveforms affect the skin when applied by IOP. In the future, these findings will be a solid foundation for developing various kinds of medical equipment such as scheduled drug delivery system that can easily deliver various types of drug.

[Anesthetic management for children undergoing magnetic resonance imaging (MRI) at Department of Anesthesia and ICU, National Center for Child Health and Development (NCCHD)]

We present here anesthetic management for children undergoing MRI at the Department of Anesthesia in NCCHD. Remaining motionless in the scanner of MRI is extremely important for data integrity because motion will blur the image. In patients who cannot remain still and in small children, general anesthesia or sedation is required for MRI. The MRI room is different from the conventional operating room as follows; the MRI machine emits the large sound continuously: the MRI room is the powerful magnetic field and the generation of radio frequency emissions necessitate the use of special equipment to provide continuous patient monitoring: the temperature in the MRI room is kept at 23 degrees to maintain the MRI machine: the patients positioned at the restricted area during the MRI scanning are hard to be accessed. We describe two cases of anesthetic management for children undergoing MRI by using propofol and in these cases we found that it should be better to follow the conventional setting for general anesthesia including monitoring system. Some hospitals encountered with serious complications such as cardiac arrest during MRI scanning under general anesthesia/sedation. MRI scanning under general anesthesia/sedation has a high risk due to the environment, indicating that we should be careful about the safety of the patients.

Risk factors with intravenous sedation for patients with disabilities

The purpose of this study was to identify the risk factors associated with low peripheral oxygen saturation (SpO2) and delayed recovery of dental patients with disabilities after intravenous sedation. A total of 1213 patients with disabilities were retrospectively investigated with respect to demographic parameters and sedation conditions. Multivariate logistic analyses were conducted for patients with an SpO2 <90% and a recovery period of >60 minutes to identify the risk factors for poor sedation conditions. A significant odds ratio related to decreased SpO2 was observed for age, sex, midazolam and propofol levels, concurrent use of nitrous oxide, cerebral palsy, Down syndrome, and mental retardation. The most problematic patients were those diagnosed with Down syndrome (odds ratio, 3.003-7.978; 95% confidence interval; P < .001). Decision tree analysis showed an increased risk of decreased SpO2 in males with Down syndrome or after administration of >0.493 mg/kg propofol in combination with midazolam. An increased risk of delayed awakening was seen in patients aged less than 21 years and in males administered >0.032 mg/kg of midazolam. Intravenous sedation for dental patients with disabilities, particularly those with cerebral palsy, Down syndrome, or mental retardation, increases the risk of decreased SpO2. In addition, delayed recovery is expected after midazolam administration.

A comparison of dexmedetomidine sedation with and without midazolam for dental implant surgery

Dexmedetomidine (DEX) has a minimal respiratory depressive effect, which is beneficial for dentistry; however, it has the disadvantage of permitting an intraoperative arousal response such that the patient appears to be suddenly no longer sedated, and it has a variable amnestic effect. Since midazolam (MDZ) in an appropriate dose has a profound amnesic effect, we investigated whether additional MDZ compensates for the disadvantage of DEX and enables a better quality of sedation. Forty-three subjects were randomly divided into 4 groups. In group 1, MDZ (0.02 mg/kg) was administered intravenously, followed by a dose of 0.01 mg/kg every 45 minutes. After the first dose of MDZ, preloading with DEX (2 µg/kg/h for 10 minutes) was started and maintained with a dosage of 0.5 µg/kg/h. In group 2, MDZ was infused in the same manner as in group 1, followed by preloading with DEX (1 µg/kg/h for 10 minutes) and maintenance (0.3 µg/kg/h). In group 3, MDZ was infused 0.03 mg/kg, and a dose of 0.01 mg/kg was given every 30 minutes; DEX was administered at the same as in group 2. In group 4, DEX was infused using the same method as in group 1 without MDZ. The sedation levels, amnesia, and patient satisfaction were also investigated. Group 2 had a lower sedation level and a poor evaluation during the first half of the operation. Group 4 did not exhibit an amnesic effect at the beginning of the operation. An evaluation of the degree of patient satisfaction did not reveal any differences among the groups. Optimal sedation was achieved through the combined use of MDZ (0.02 mg/kg with the addition of 0.01 mg/kg every 45 minutes) and DEX (2 µg/kg/h for 10 minutes followed by 0.5 µg/kg/h).

Heterogeneous electrophysiological and morphological properties of neurons in the mouse medial amygdala in vitro

Neurons in the medial nucleus of the amygdala (MeA) play a key role in the innate maternal, reproductive, defensive, and social behaviors. However, it is unclear how activation of the vomeronasal system leads to the behavioral outputs that are associated with pheromones. Here, we characterized the electrophysiological and morphological properties of MeA neurons using whole-cell recordings in mice slice preparations. Biocytin labeling revealed that MeA neurons possessed bipolar to multipolar cell bodies and dendritic fields covering projection areas from the accessory olfactory bulb. In 70% of recorded MeA neurons, monosynaptic excitatory postsynaptic currents (EPSCs) were evoked from the accessory olfactory bulb afferent in which the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate component was dominant and was rarely followed by the N-methyl-d-aspartic acid component. Norepinephrine increased the frequency of spontaneous inhibitory postsynaptic currents in some neurons, whereas α-methyl-5-hydroxytryptamine increased spontaneous EPSCs in other neurons. Morphologically and physiologically, heterogeneous MeA neurons appear likely to produce multiplex outputs of instinctive behaviors.

In vitro evaluation of calcium alginate gels as matrix for iontophoresis electrodes

Calcium alginate gel has some unique properties, such as the capability to keep the drugs, bioadhesiveness, safety, and low cost. The purpose of this study is to determine whether calcium alginate gel can be used as a matrix of electrodes for iontophoresis (IOP). We measured the concentration of lidocaine transported from calcium alginate gels with various concentrations of alginic acid using an in vitro experimental cell with square-wave alternating current (AC) application. Temperature and pH changes were also determined during AC-IOP. The results revealed that lidocaine was released from calcium alginate gels at concentrations nearly 1.71-fold larger at 5 V, 60 min after AC application than in the case of passive diffusion. Lidocaine transport depended on the alginic acid concentration in the gels. Although there were slight increases in temperature and pH, chemical and thermal burns were not severe enough to be a concern. In conclusion, the calcium alginate gel can be used as a possible matrix for IOP electrodes.

The relation between the duty cycle and anesthetic effect in lidocaine iontophoresis using alternating current

We assessed the effect of the duty cycle on the anesthetic effect during lidocaine alternating current (AC) iontophoresis. A solution of 2% lidocaine was delivered to the medial antecubital skin for 20 minutes using AC iontophoresis with a duty cycle of 60%, 70%, or 80%. The von Frey test was then performed to evaluate the anesthetic effect. In the groups treated with a duty cycle of 80% or 70% the touch thresholds (TT) were significantly elevated from 0 minutes to 30 minutes and from 0 minutes to 20 minutes. TT were significantly elevated at 0 minutes in the group treated with a 60% duty cycle. The anesthetic effect was significantly enhanced in a duty cycle-dependent manner.

General anesthesia for a patient with deletion 6q syndrome in addition to laryngomalacia undergoing dental treatment

Chromosome 6 deletions are very rare (1,2), and deletion 6q syndrome is clinically characterized by mental and/or neuromotor retardation and microcephaly (3). Other alterations frequently observed are decreased biparietal diameter, hypertelorism, hypotelorism, absent eyebrows, prominent eyes with ptosis, receding chin, dysmorphic ears, large extremities, prominent nasal bridge, long philtrum, epicthus, strabismus, and micrognathia (3-5). Laryngomalacia is the most common congenital laryngeal anomaly and the most frequent cause of stridor in infants (6-11). We report the case of a 14-year-old male patient with both deletion 6q syndrome and laryngomalacia, who we treated for multiple dental caries. He had a medical history of tracheotomy at age 11 years for laryngomalacia, and has suffered from epileptic attacks and aspiration pneumonia over the last 2 and 6 years, respectively. Since he was mentally retarded and in a poor respiratory state, dental treatment under general anesthesia was scheduled in our hospital. General anesthesia was induced and maintained using 30% nitrous oxide and 1-3% sevoflurane in oxygen through the tracheotomy tube. Pre- and intraoperative endotracheal suction improved the condition of both lungs markedly and the procedures were uneventful and completed in 2 h and 58 min.

Monitoring of vital signs during dental care

Advances in medicine have greatly increased the survival of patients with severe health problems and have significantly prolonged life in elderly individuals with systemic disorders. Concomitant advances in dentistry and evolving societal expectations regarding dental health and function have likewise ensured that these patients are increasingly retaining their teeth and/or seeking dental care. The administration of local anaesthetics and the performance of extensive dental procedures may cause stress and systemic disturbances in such patients. In order to avoid potentially serious reactions, dentists are obligated to monitor continuously their medically challenged patients. Monitoring provides three important benefits. First, it helps the dentist detect acute medical emergencies that may require an immediate response. Second, monitoring may reveal gradual deleterious trends that can often be easily reversed before a true emergency occurs. Third, monitoring can assist the dentist in evaluating the efficacy of any emergency treatments or preventive measures that are rendered. The purposes of this article are to: briefly review monitoring techniques and devices, discuss their suitability for use in the dental office, and provide some tips for their application during dental care. In overall decreasing order of routine importance, monitoring resources include the following: responsible personnel, non-invasive blood pressure monitor, pulse oximeter, ECG, and the pretracheal stethoscope or capnograph.

The Different Effects of Intravenous Propofol and Midazolam Sedation on Hemodynamic and Heart Rate Variability

Heart rate (HR) and arterial blood pressure (BP) changes have been reported during conscious sedation with propofol and midazolam. One potential mechanism to explain these changes is that propofol and midazolam affect HR and BP via changes in the cardiac autonomic nervous system. Two specific hypotheses were tested by HR variability analysis: 1) propofol induces predominance of parasympathetic activity, leading to decreased HR and BP, and 2) midazolam induces predominance of sympathetic activity, leading to increased HR and decreased BP. Thirty dental patients were included in a prospective, randomized study. HR, BP, low frequency (LF), high frequency (HF), and entropy were monitored during the awake, sedation, and recovery periods and depth of sedation was assessed using the Observer's Assessment of Alertness/Sedation score. Propofol induced a significant decrease in total power (503 +/- 209 ms(2)/Hz versus 162 +/- 92 ms(2)/Hz) and LF/HF ratio (2.5 +/- 1.2 versus 1.0 +/- 0.4), despite the absence of any change in HR during the sedation period compared with baseline. Midazolam decreased normalized HF (34 +/- 10% versus 10 +/- 4%) but did not significantly change LF/HF ratio (2.3 +/- 1.1 versus 2.2 +/- 1.4) and increased HR in the sedation period. Compared with baseline, propofol was associated with a significant increase in normalized HF in the recovery period (34 +/- 11% versus 44 +/- 12%) and a significant decrease in HR, whereas midazolam was associated with an increase in LF/HF ratio (2.3 +/- 1.1 versus 3.7 +/- 1.8) with no change in HR. These results indicated a dominant parasympathetic effect of propofol and a dominant sympathetic effect of midazolam in both periods. These results should be considered during conscious sedation, especially in patients at risk of cardiovascular complications.

Postoperative Hyperthermia of Unknown Origin Treated With Dantrolene Sodium

An 11-year-old girl was scheduled for alveolar cleft bone grafting with an iliac bone under general anesthesia. Anesthesia was performed with 70% nitrous oxide, 30% oxygen, and propofol. On the first and second postoperative day, persistent hyperthermia was observed. Because the administration of diclofenac sodium had not been effective for the hyperthermia, dantrolene sodium was given. Her body temperature gradually dropped and returned to normal level on the fifth postoperative day. The hyperthermia in the present case might have been caused by a rapidly elevated muscle metabolism in response to pain and stress after the propofol anesthesia. The oral administration of dantrolene sodium successfully lowered the patient's high body temperature.

Efficacy of anterior and middle superior alveolar (AMSA) anesthesia using a new injection system: the Wand

OBJECTIVE

This study examined the effect of anterior and middle superior alveolar (AMSA) field block of maxillary nerves using a new local anesthetic system--the Wand.

METHOD AND MATERIALS

Twenty healthy volunteers aged 23 to 44 years were used in the study. Either side of the maxillary teeth was randomly selected for AMSA injection; the other side was left as a control. For each side, 1.8 mL of 2% lidocaine solution with 1/80,000 epinephrine was injected by the Wand on a point that bisects the maxillary first and second premolars and is midway between the crest of the free gingival margin and the midpalatine suture. Pain rating score (PRS) and visual analogue scale (VAS) were applied for measurement of puncture, insertion, and injection pain. Electric pulp stimulation was given to each maxillary tooth every 10 minutes for 1 hour after the injection in order to find out the specific tooth on which AMSA injection was effective.

RESULTS

During needle insertion, 14 out of 20 subjects answered moderate pain and VAS showed 27.3 mm (mean). During injection, 11 of 20 revealed no pain and the mean of VAS was 14.5 mm. No one claimed severe pain by PRS. Electric pulp stimulation indicated that lateral incisors, canines, and first and second premolars were more anesthetized than central incisors and first molars.

CONCLUSION

AMSA injection using the Wand method seems to avoid severe injection pain and seems to be very effective for pulpal anesthesia at lateral incisors, canines, and premolars.

Intravenous sedation and general anesthesia for a patient with Gilles de la Tourette's syndrome undergoing dental treatment

Patients with Gilles de la Tourette's syndrome develop symptoms during childhood. Repetitive various motor tics or speech tics that are spontaneous, aimless, and involuntary are characteristic of the syndrome (1). Patients with the syndrome have been considered to have an aggressive, impulsive, and obsessive character (2). (3). Suicide is one of the mental symptoms of the syndrome. Routine dental treatment with this syndrome can be difficult.

Comparison of topical anesthesia of 20% benzocaine and 60% lidocaine gel

OBJECTIVE

The purpose of this study was to determine the efficacies of 2 topical anesthetics commonly used in dentistry.

STUDY DESIGN

The alveolar mucosa of the upper incisor apices of 20 healthy male volunteers was applied for 20 minutes with either 20% benzocaine gel or nothing as a control. The second part of experiment was done with 60% lidocaine gel and vehicle as control. Three methods of stimulation were given, and the pain rating score and visual analog scale were measured after each stimulation.

RESULTS

Twenty percent benzocaine did not significantly alter pain perception as measured by the pain rating score and visual analog scale with these 3 methods of stimulation. In contrast, 60% lidocaine significantly reduced pain perception according to these measurements. We conclude that 60% lidocaine gel is effective for topical anesthesia before infiltration anesthesia.

Significant accumulation of C(4)-specific pyruvate, orthophosphate dikinase in a C(3) plant, rice

The C(4)-Pdk gene encoding the C(4) enzyme pyruvate, orthophosphate dikinase (PPDK) of maize (Zea mays cv Golden Cross Bantam) was introduced into the C(3) plant, rice (Oryza sativa cv Kitaake). When the intact maize C(4)-Pdk gene, containing its own promoter and terminator sequences and exon/intron structure, was introduced, the PPDK activity in the leaves of some transgenic lines was greatly increased, in one line reaching 40-fold over that of wild-type plants. In a homozygous line, the PPDK protein accounted for 35% of total leaf-soluble protein or 16% of total leaf nitrogen. In contrast, introduction of a chimeric gene containing the full-length cDNA of the maize PPDK fused to the maize C(4)-Pdk promoter or the rice Cab promoter only increased PPDK activity and protein level slightly. These observations suggest that the intron(s) or the terminator sequence of the maize gene, or a combination of both, is necessary for high-level expression. In maize and transgenic rice plants carrying the intact maize gene, the level of transcript in the leaves per copy of the maize C(4)-Pdk gene was comparable, and the maize gene was expressed in a similar organ-specific manner. These results suggest that the maize C(4)-Pdk gene behaves in a quantitatively and qualitatively similar way in maize and transgenic rice plants. The activity of the maize PPDK protein expressed in rice leaves was light/dark regulated as it is in maize. This is the first reported evidence for the presence of an endogenous PPDK regulatory protein in a C(3) plant.

High level expression of C4-specific NADP-malic enzyme in leaves and impairment of photoautotrophic growth in a C3 plant, rice

The chloroplastic NADP-malic enzyme (NADP-ME) is a key enzyme of the C4 photosynthesis pathway in NADP-ME type C4 plants such as maize. To express the chloroplastic NADP-ME in leaves of a C3 plant, rice, full-length cDNAs encoding the rice C3-specific isoform and the maize C4-specific isoform of the enzyme were expressed under the control of the rice CAB: promoter. Transformants carrying the rice cDNA showed the NADP-ME activities in the leaves less than several-fold that of non-transformants, while those carrying the maize cDNA showed activities up to 30-fold that of non-transformants or about 60% of the NADP-ME activity of maize leaves. These results indicate that expression of the rice C3-specific NADP-ME is suppressed at co- and/or post-transcriptional levels by some regulation mechanisms intrinsic to rice, while that of the foreign C4-specific isoform can escape from such suppression. The accumulation of the maize C4-specific NADP-ME led to bleaching of leaf color and growth hindrance in rice plants under natural light. These deteriorative effects resulted from enhanced photoinhibition of photosynthesis due to an increase in the level of NADPH inside the chloroplast by the action of the maize enzyme.

Benign hyperthermia following prolonged TIVA with propofol

PURPOSE

Propofol is widely used for general anesthesia because of its rapid onset and recovery. We had four cases that had higher body temperatures toward the end of anesthesia. The etiology of the hyperthermia is discussed.

CLINICAL FEATURES

Four patients (three male, one female, 22-26 yr of age, weighing 53-57 kg) with facial deformities were anesthetized with propofol infusion (3-10 mg x kg(-1) x hr(-1)) and fentanyl (400-1,300 microg) without nitrous oxide, immobilized with vecuronium bromide (18-37 mg) or pancuronium bromide (31 mg). In order to reduce blood loss and improve the surgical view, tri-nitro-glycerin (TNG) was used in all cases. Osteotomy of maxilla and mandible or sagittal split ramus osteotomy of mandible was successfully performed. Although their body temperatures were normal preoperatively and stable during the operation, toward the end of anesthesia (one hour), they increased to over 38 degrees C. The room temperature was decreased and the water blanket on the operating table was also decreased. In addition, cool crystalloid solution was infused. Body temperature returned to normal in the ward and no complications due to the high temperature were seen postoperatively. It is thought that lighter anesthesia was masked by continuous infusion of propofol and TNG-induced hypotension and that benign hyperthermia occurred toward the end of anesthesia.

CONCLUSION

Propofol reduces blood pressure, which suggests deep anesthesia. However, care must be taken to maintain the optimum depth of anesthesia during propofol anesthesia, especially when deliberate hypotensive anesthesia is induced.