Suspected Metallic Embolism following Endovascular Treatment of Intracranial Aneurysms

We describe a case series of suspected metallic embolism after coil embolization for intracranial aneurysms. Between January 2012 and December 2014, 110 intracranial aneurysms had been treated by coil embolization in our institution. In 6 cases, the postprocedural MR imaging revealed abnormal spotty lesions not detected on the preprocedural MR imaging. The lesions were also undetectable on the postprocedural CT scan. They were demonstrated as low-intensity spots on T1WI, T2WI, DWI, and T2*-weighted imaging. On DWI, they were accompanied by bright "halo," and on T2*-weighted imaging, they showed a "blooming" effect. In 3 of the 6 cases, follow-up MR imaging was available and all the lesions remained and demonstrated no signal changes. Although histologic examination had not been performed, these neuroradiologic findings strongly supported the lesions being from metallic fragments. No specific responsible device was detected after reviewing all the devices used for the neuroendovascular treatment in the 6 cases.

Reduced cortical expression of a newly identified splicing variant of the DLG1 gene in patients with early-onset schizophrenia

The human discs, large homolog 1 gene (DLG1) is mapped to the schizophrenia-susceptibility locus 3q29, and it encodes a scaffold protein that interacts with the N-methyl-D-aspartate receptor presumably dysregulated in schizophrenia. In the current study, we have newly identified a splicing variant of DLG1, which is transcribed from an unreported 95-base-pair exon (exon 3b) and is labeled 3b(+). We investigated the mRNA expression of 3b(+) in the post-mortem dorsolateral prefrontal cortices of patients with psychiatric disorders, obtained from The Stanley Medical Research Institute, and examined the potential association of the expression with the genotype of the single-nucleotide polymorphism (SNP) rs3915512 located within exon 3b. A real-time quantitative reverse transcriptase-polymerase chain reaction revealed that the mRNA levels of 3b(+) were significantly reduced in patients with early-onset schizophrenia (onset at <18 years old, P=0.0003) but not in those with non-early-onset schizophrenia, early-onset or non-early-onset bipolar disorder or in the controls. Furthermore, the genotype at the rs3915512 SNP was closely associated with the levels of 3b(+) mRNA expression. It is inferred that the T allele fails to meet the exonic splicing enhancer consensus, thus resulting in skipping of exon 3b, leading to the expression of 3b(-) (the previously known DLG1 variant) but not 3b(+). Because all the subjects with early-onset schizophrenia in the current study possess the T/T genotype, the reduced level of the DLG1 3b(+) transcript may be involved in the susceptibility and/or pathophysiology of early-onset schizophrenia.

Increase in hemokinin-1 mRNA in the spinal cord during the early phase of a neuropathic pain state

BACKGROUND AND PURPOSE

Substance P (SP), a representative member of the tachykinin family, is involved in nociception under physiological and pathological conditions. Recently, hemokinin-1 (HK-1) was identified as a new member of this family. Although HK-1 acts on NK(1) tachykinin receptors that are thought to be innate for SP, the roles of HK-1 in neuropathic pain are still unknown.

EXPERIMENTAL APPROACH

Using rats that had been subjected to chronic constrictive injury (CCI) of the sciatic nerve as a neuropathic pain model, we examined the changes in expression of SP- and HK-1-encoding genes (TAC1 and TAC4, respectively) in the L4/L5 spinal cord and L4/L5 dorsal root ganglia (DRGs) in association with changes in pain-related behaviours in this neuropathic pain state.

KEY RESULTS

The TAC4 mRNA level was increased on the ipsilateral side of the dorsal spinal cord, but not in DRGs, at day 3 after CCI. In contrast, the TAC1 mRNA level was significantly increased in the DRGs at day 3 after CCI without any changes in the dorsal spinal cord. Analysis of a cultured microglial cell line revealed the presence of TAC4 mRNA in microglial cells. Minocycline, an inhibitor of microglial activation, blocked the increased expression of TAC4 mRNA after CCI and inhibited the associated pain-related behaviours and microglial activation in the spinal cord.

CONCLUSIONS AND IMPLICATIONS

The present results suggest that HK-1 expression is increased at least partly in activated microglial cells after nerve injury and is clearly involved in the early phase of neuropathic pain.

Haemodynamic changes and heart rate variability during midazolam-propofol co-induction

In a prospective, blind, randomised study, we examined the effects of midazolam-propofol co-induction on haemodynamic (blood pressure, heart rate and stroke volume) and heart rate variability. The latter was measured by spectral analysis using the maximum-entropy method to calculate the following: the low frequency component (LF), which reflects both the cardiac sympathetic and parasympathetic activity, the high frequency component (HF) and entropy, which reflects the cardiac parasympathetic activity, the total power (TP), calculated by the addition of LF and HF, and the LF/HF ratio, which reflects the balance between the cardiac sympathetic and parasympathetic nervous activity. Forty patients were randomly allocated to the propofol group and the midazolam-propofol group, and the parameters described above were calculated at baseline (T1), post induction (T2), after tracheal intubation (T3), and 3 min (T4) and 5 min after intubation (T5). Propofol was administered at 2.5 mg.kg(-1) in the propofol group and midazolam at 0.1 mg.kg(-1) followed by propofol at 1.5 mg.kg(-1) in the midazolam-propofol group for anaesthesia induction. Then, propofol was administered at 4-6 mg.kg(-1)propofol for maintenance in both groups. The midazolam-propofol group showed compensated haemodynamic changes, which were related to significant increases in the LF/HF ratio at T2, T4 and T5 (p = 0.011, 0.038 and 0.034). These results suggest that the midazolam-propofol combination yielded compensated modulatory effects on the cardiovascular system, including preserved baroreflex activity.

Delirium during intravenous sedation with midazolam alone and with propofol in dental treatment

A 62-year-old man visited our clinic for dental implantation under intravenous sedation. He demonstrated increased psychomotor activity and incomprehensible verbal contact during intravenous sedation. Although delirium caused by midazolam or propofol in different patients has been reported, the present case represents a delirium that developed from both drugs in the same patient, possibly because of the patient's smaller tolerance to midazolam and propofol.

Lidocaine transport through living rat skin using alternating current

The purpose of the study was to determine whether lidocaine could be transported through living rat skin using alternating current and to determine whether lidocaine transport depends on voltage. The drug delivery cell was originally constructed for the application of an electric field. Hairless rats were anaesthetised using sevoflurane, and a tracheotomy was performed. The drug delivery cell, with lidocaine solution in the donor cell, was placed on the abdominal skin. Samples were collected from the subcutaneous tissue using a microdialysis probe inserted into the abdominal subcutaneous tissue, and the lidocaine concentrations in the samples were determined using high-performance liquid chromatography. The lidocaine concentration in the rat skin increased in time, and voltage-dependency was approximately linear. The lidocaine concentration after the application of 20 V for 21 min was about ten-fold higher than that observed after 21 min of passive diffusion. Lidocaine was successfully transported through living rat skin in a voltage- and time-dependent manner. This drug delivery cell may contribute to local anaesthesia and pain management of human skin.

Tracheal intubation using a new CCD camera-equipped device: a report of two cases with a difficult intubation

In two patients, one with Klippel-Feil syndrome and one with fibrous dysplasia of the maxilla, no part of the larynx could be visualized by direct laryngoscopy. In both cases, the use of an intubation device equipped with a charge-coupled device camera, the endotracheal intubation device (EID), allowed smooth tracheal intubation.

Application of a mandibular nerve block using an indwelling catheter for intractable cancer pain

We report a case in which a mandibular nerve block using an indwelling catheter was employed for pain management in a terminal case of orofacial cancer. The patient was a 74-year-old female weighing 27 kg. She had a 27-month history of mouth floor and tongue cancer. The cancer recurred and spread to bilateral face and neck. The severest pain mainly originated from the right mandibular region. Two steps of pain relief were performed for the patient. First, pain control using 1% lidocaine or 0.25% bupivacaine administered intermittently or continuously through an indwelling catheter in the mandibular nerve was performed for 1 week to estimate the amount of pain relief thereby obtained. Second, a neurolytic block was applied to the mandibular nerve through the catheter. After the neurolytic block, the total dosage of morphine and diclofenac remained unchanged for 2 months. We conclude from the present case that this technique is an excellent means of obtaining long-term pain control in patients with intractable orofacial cancer pain.

Decreased bispectral index as an indicator of syncope before hypotension and bradycardia in two patients with needle phobia

We report two cases who exhibited a decrease in their bispectral index (BIS) score, associated with syncope during venipuncture in patients with suspected needle phobia. In case 1, the reduction in BIS score occurred during the development of hypotension and bradycardia and may well have been caused by cerebral hypoperfusion. In case 2, the patient lost consciousness with decreasing BIS score before hypotension and bradycardia; this patient's condition could not be completely explained by cerebral hypoperfusion as a result of a vasovagal reflex because the patient's blood pressure and heart rate remained normal during the syncopal episode.

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.

Experimental and theoretical studies of the effect of electrode polarisation on capacitances of blood and potassium chloride solution

The effects of electrode polarisation on the observed capacitances of electrolytic solutions, including whole blood, plasma and potassium chloride solution, have been investigated experimentally in the frequency region from 10 to 10(5) Hz, by varying the area of the electrodes using plate and mesh electrodes, by varying the electrode distance, and by varying the concentration of KCl in the potassium chloride solution. The effects of the electrode polarisation on the observed capacitances were most significant in the frequencies lower than 10(2) Hz, but cannot be neglected in any frequency region. The so-called alpha dispersion observed in the frequencies lower than about 10(3) Hz was reproduced theoretically with an equivalent circuit model, using constant values independent of frequency for the four circuit parameters: sample capacitance, sample conductivity, electrode polarisation capacitance and electrode polarisation conductivity. It was concluded that the observed alpha dispersion is not a real one that represents the specific features of the samples themselves, but an apparent one that represents the characteristics of the whole measurement system, including the electrode polarisation.

A mechanism of the high frequency AC iontophoresis

The efficiency and the voltage dependence of the AC iontophoresis were studied in vitro. Two cylindrical glass cells separated by a cellophane film were used, where the donor cell was filled with the solution of target electrolytes and the receptor cell with distilled water. The sinusoidal AC voltage with a frequency of 1 kHz was applied between the two platinum plates located at the opposite ends of two cells. The time variation of the ion concentration was evaluated by measuring the impedance of the solution in the receptor cell. The transportation velocity of the ions increased with the amplitude of the voltage applied between two platinum plate electrodes apart 20 mm up to approximately 15 V, and leveled off above approximately 15 V. A theoretical model is proposed on the AC iontophoresis, where each ion moves together with the surrounding water molecules when it is hydrated. The effective Stokes radius of an ion is assumed to be half of the whole size of the ion with hydrating water molecules. When the external alternating electric field strongly vibrates the ion, the ion-dipole interactions between the ion and water molecules are broken, resulting in the reduced effective Stokes radius, which leads to the increase of the diffusion efficiency.

Heterotopic painful stimulation decreases the late component of somatosensory evoked potentials induced by electrical tooth stimulation

The purpose of this study was to determine the relationship between the late component of somatosensory evoked potentials (SEP) induced by electrical tooth stimulation and subjective pain estimation when heterotopically painful stimulation was delivered to humans. The noxious electrical conditioning stimuli were applied to the left median nerve in noxious session I and the right median nerve in noxious session II for 10 min. The amplitude of the late component and visual analogue scale (VAS) value were both decreased significantly by conditioning stimuli in both sessions. The maximum decreases in SEP amplitude and VAS value induced by conditioning stimuli were respectively 40.2 and 37.2% in noxious session I and 49.3 and 42.3% in noxious session II. After-effect was observed 5 min after removal of the conditioning stimuli. The rates of decrease were thus nearly the same and independent of the site of conditioning stimulation in noxious sessions I and II. The SEP amplitude was significantly correlated with VAS values. The present study revealed that SEP amplitude and subjective pain intensity estimated by VAS following electrical tooth stimulation can be decreased by noxious stimuli to hand. This finding that heterotopic painful stimulation attenuates experimentally-induced tooth pain suggests a triggering of diffuse noxious inhibitory control (DNIC) with after-effect in trigeminal region.

Morphological evaluation of the baboon hind limb muscles based on relative weight

Morphological features of the hind limb muscles reflect the muscular function correlating with the locomotion. In this study, the muscles of the baboon hind limb were weighed and the relative muscle weights were compared with those of the human lower extremity. In the baboon, the biceps femoris was the largest (11.60%) and the vastus lateralis (10.67%) was placed second. The gluteus medius (8.55%) among the hip muscles and the gastrocnemius (4.38%) among the leg muscles were predominant in each segment. The relative weights of the gluteus medius and the biceps femoris were especially larger in the baboon than in the human, while the gluteus maximus and the soleus were larger in the human. The baboon gluteus medius and biceps femoris chiefly generate the propulsive power during quadrupedal locomotion and the human soleus is essential for the erect bipedalism.

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.

[Dental treatment for the handicapped by a combination of public community, dental association and university hospital--a system of Suginoki Dental Clinic]

Suginoki Dental Clinic, which is managed by Suginami Dental Association, financially supported by Suginami City, and technically assisted by the University Hospital, Tokyo Medical and Dental University, was established for dental treatment of handicapped persons living in Suginami City, Tokyo who are difficult to be treated by private practitioners. It has one full-time dentist, 12 part-time dentists, two dental hygienists, one nurse, and one clerk; one of the part-time dentists practices twice a week there. Since December 1994, 406 patients visited the clinic and the total cases was 9,273 in December 1999; 99 cases were mentally retarded, 36 autism, and 30 epileptic patients in the younger group; and 65 cases were cerebrovascular disease and 27 cardiac malfunction patients in the older group. Almost all the patients needed special care such as monitoring, intravenous sedation, nitrous oxide sedation, and general anesthesia. Four cases underwent general anesthesia, and no complication was seen among the cases. It was concluded that the clinic has been successful due to a good relationship among the Dental Association, Suginami City, and the dental hospital.

Trigeminally induced cardiovascular reflex responses in spinalized rats

The effects on cardiovascular functions of noxious stimulation to the orofacial areas innervated by trigeminal afferent nerves were analyzed in urethane-anesthetized, spinal cord-intact rats and in rats acutely spinalized at the second cervical level. In the spinal cord-intact rats, pinching of the upper lip produced increases in both heart rate (HR) and mean arterial pressure (MAP). Both responses were considered to be due to activation of sympathetic efferent nerves to the cardiovascular organs. Both responses were attenuated but did not disappear after spinalization at the C2 level. In spinalized rats, sympathetic preganglionic neurons emerging from the thoracolumbar spinal cord could not receive any neural influences from the brain. The HR response in the spinal rats was abolished after either bilateral vagotomy or intravenous injection of a peripherally acting muscarinic cholinergic receptor antagonist, methylatropine. This suggests that the increase in HR was elicited via vagal cholinergic efferent fibers, probably by decreasing tonic activity of vagus nerves to the heart. In spinal rats, neither vagotomy nor cholinergic blockade affected the increase in MAP, but i.v. injection of the vasopressin V1 receptor antagonist, OPC-21268, abolished the response of MAP. This suggests that the response of MAP was due to peripheral vasoconstriction elicited by vasopressin secreted from the posterior pituitary lobe. The present study demonstrated that, in rats acutely spinalized at the C2 level, noxious stimulation of orofacial areas innervated by the trigeminal nerve could produce reflex increases both in HR, by decreasing cholinergic vagal nerve activity to the heart, and blood pressure, by secreting vasopressin from the pituitary gland, even though sympathetic efferent innervation to the cardiovascular organs could not be directly affected by trigeminal afferent nerve excitation.

Effects of propofol on a Ca2+-activated CI- current in rabbit ventricular myocytes

Propofol is a widely used intravenous anesthetic, which is known to affect cardiac functions. Cardiac effects may be caused by direct actions on ion channels of the heart. While effects of propofol on several ion channels have been studied at the whole cell and single-channel levels, its effects, if any, on anion currents have yet to be examined. Effects of propofol on Ca2+-activated Cl- current (I(Cl(Ca))) were investigated in single myocytes isolated from rabbit ventricles by the whole-cell patch clamp technique at 36 degrees C. I(Cl(Ca)) was activated by perfusing internal solutions with 0.1 microM free Ca2+ in the absence and presence of 10 mM internal Na+, eliciting I(Ca)-dependent and -independent component, respectively. By the application of propofol (0.1-300 microM), I(Ca)-independent I(Cl(Ca)) was strongly inhibited in a dose-dependent manner with an IC50 of about 5 microM. The blocking effects of propofol were voltage independent. On the other hand, the I(Ca)-dependent component of I(Cl(Ca)) was little affected by propofol at concentrations of up to 50 microM. The outward Na+/Ca2+ exchanger current was also blocked by application of 5 microM propofol. We conclude that propofol inhibits cardiac I(Cl(Ca)) in rabbit ventricular myocytes, mainly the I(Ca)-independent component, at therapeutic concentrations. The inhibition may be due to block of a reverse mode of Na+/Ca2+ exchange current.

[Transient global amnesia after general anesthesia]

A 61 year old male patient with left mandibular cyst, received marsupialization of the left mandible under general anesthesia. Four hours after the end of anesthesia, his memory for the past 4 months and short term memory plastisity were impaired. No neurological abnormalies were found at that time. On the 2nd postoperative day, he recovered his lost memory for the past 4 months. The memory of events between 6 hours before operation and next morning, however, remained lost. It is suggested that the memory disorder is the TGA due to various causes including transient hypertension, operative stress, postoperative pain and diazepam.

Unexpected atrial fibrillation during tooth extraction in a sedated elderly patient

A case is reported of unexpected atrial fibrillation in response to tooth extraction under intravenous sedation in a 70-yr-old patient with thoracic aneurysm of the aorta. Atrial fibrillation developed after the additional injection of a 2% solution of lidocaine containing 1:200,000 epinephrine. After 20 min, the arrhythmia disappeared spontaneously. The arrhythmia was associated with insufficient analgesia for tooth extraction, epinephrine in the local anesthetic, decreased blood pressure, and the presence of cardiovascular disease. Even when a low concentration of epinephrine is employed, caution should be paid to development of unexpected cardiovascular reactions in elderly patients with severe cardiovascular disease. We conclude that an electrocardiogram, blood pressure device, and pulse oximeter should be used in high-risk patients in order to prevent and detect potentially dangerous cardiovascular emergencies, even if dental treatment is scheduled under local anesthesia.

Long-term observation of the relation between pain intensity and serum carbamazepine concentration in elderly patients with trigeminal neuralgia

The relation between changes in pain intensity and serum carbamazepine (CBZ) concentration was studied in five elderly patients with trigeminal neuralgia. Measurement of pain intensity and serum CBZ concentration, and blood studies, were performed approximately every 2 or 3 months after initiation of CBZ therapy. Fluctuations in pain intensity were observed in four patients. In these patients, even when the serum CBZ concentration was maintained within a relatively high range, there were periods in which pain intensity increased. On the other hand, there were periods in which pain was relatively well controlled even though the CBZ concentration was relatively low. There were considerable interindividual differences in response to CBZ. The fluctuations in pain showed that the CBZ response curve varies from period to period even within an individual. It was concluded that it is essential to observe spontaneous variations in pain intensity and monitor serum CBZ during long-term administration.

Systemic diseases in elderly dental patients

Systemic diseases, blood pressure and pulse rate, were investigated in 1012 elderly patients who consulted the gerodontic clinic of Tokyo Medical and Dental University Hospital. One or more systemic diseases was found in 64.2 per cent of the subjects. Hypertension was the most frequent systemic disease, occurring in 30.9 per cent of the subjects, and was followed by angina pectoris, diabetes, arrhythmias, digestive diseases, cerebrovascular diseases and myocardial infarction, respectively. Nearly 17 per cent of the patients had two or more diseases. Among these diseases, hypertension was frequently combined with angina pectoris, myocardial infarction, arrhythmia, and cerebrovascular diseases. Patients with systemic diseases are at a greater risk during dental treatment. Psychosomatic stress and vasoconstrictors in local anaesthesia possibly induce the exacerbation of systemic diseases or unexpected cardiovascular reactions. Isolated systolic hypertension (systolic blood pressure of 160 mm Hg or more) was noted in 14.3 per cent of the patients. Among these patients, 6.3 per cent of patients were hypertensive patients who had both above 160 mm Hg systolic pressure and 95 mm Hg diastolic pressure. Elderly dental patients have various systemic diseases. Accordingly, it is very important for the dentist to identify systemic diseases of patients and to understand systemic conditions before treatment commences.

Effects of extensive oral surgery and hemorrhage on coagulation and fibrinolysis

The changes in coagulation and fibrinolytic activity in 22 patients with oral cancer undergoing extensive surgical procedures were studied. The patients were divided into two groups: group I patients suffered blood loss of less than 2,000 mL and group II patients had blood loss of more than 2,000 mL. The platelet count decreased significantly during surgery, at the end of surgery and on the 1st postoperative day in both groups. Fibrinogen was decreased during and at the end of surgery in both groups, but increased significantly on the 3rd postoperative day and reached about two times the preoperative levels on the 7th postoperative day. Fibrin degradation products increased significantly after surgery and reached the maximum value on the 1st postoperative day in both groups. Plasmin inhibitor complex and plasminogen increased significantly on the 3rd and 7th postoperative days. There was no clear evidence regarding the influence of blood loss on coagulation and fibrinolytic factors except for platelets. It was concluded that coagulation and fibrinolysis are enhanced between the 3rd and 7th postoperative days.

[Acute and chronic effects of a new oral inotropic agent, ibopamine hydrochloride, on hemodynamic and metabolic responses to ergometer exercise in patients with severe congestive heart failure]

The hemodynamic and metabolic effects of ibopamine, an orally active 3,4-diisobutylic ester of N-methyl-dopamine, at rest and during exercise, were evaluated in 8 patients with severe congestive heart failure, initially at 2 hrs after oral 100 mg and after 4 weeks of maintenance therapy (100 mg, 3 times a day). At rest, a single dose of ibopamine increased CI, SVI and SWI, and reduced PCWP, PAm, RA and PVR. These beneficial hemodynamic effects were maintained during supine bicycle exercise: CI and SVI increased markedly (p less than 0.05) and PCWP, PAm, RA and SVR increased at a lower extent (p less than 0.05) after ibopamine than on control conditions. After chronic therapy with the drug, LVDd and CTR decreased (p less than 0.05) and exercise tolerance time increased (p less than 0.01). HR, BPm, double product, norepinephrine, epinephrine, renin activity, aldosterone and lactate/pyruvate did not change significantly after administration of ibopamine. Clinical responses after 4 weeks of maintenance therapy were good in 4 cases and fair in 1 case. No adverse effects were observed. Therefore, ibopamine seems to have not only a positive inotropic action, but also a potent vasodilating action, leading to both afterload and preload reduction and so to be useful for the treatment of severe congestive heart failure at rest and during exercise after acute and chronic therapy with the drug.

Relationship between subjective pain estimation and somatosensory evoked potentials by electrical tooth stimulation

The relationship between the amplitude of somatosensory evoked potentials (SEP) and the subjective pain estimation using a visual analogue scale (VAS) was examined in 8 volunteers undergoing randomized electrical tooth stimulation with 3 different intensities. Randomized stimulation was used instead of repetitive stimulation with a fixed intensity in order to minimize the phenomena of habituation and expectancy in recording the SEP and VAS. The VAS scores increased significantly with the stimulus intensity. The amplitude with a latency between 160 and 300 msec (N160-P300) showed a significant increase with the increased intensity. But the amplitudes between 60 and 110 msec (N60-P110) and between 110 and 160 msec (P110-N160) showed no significant change. There was a significant correlation between the amplitude of N160-P300 and the VAS scores. These findings indicate that the component between 160 and 300 msec reflects the perceived pain intensity and the psychological evaluation processes such as cognition, meaning, interpretation and appreciation of pain. The method of randomized stimulation can serve as a simple and useful way for the objective or subjective pain estimation.

Automated determination of drugs in serum by column-switching high-performance liquid chromatography. II. Separation of theophylline and its metabolites

The automated determination of theophylline and related compounds in human serum by column-switching high-performance liquid chromatography, including direct injection of serum samples, is described. TSK pre-column BSA-ODS and TSK gel ODS-80TM were used in the pre-column and analytical column, respectively. Serum samples of 20 microliters were directly injected on to the pre-column. After washing out serum proteins from the pre-column with 0.1 M NaH2PO4 at a flow-rate of 1.0 ml/min for 3.5 min, the effluent from the pre-column was introduced on to the analytical column by a column-switching device. The analysis was performed by stepwise gradient elution using 10 and 18% methanol in 0.1 M NaH2PO4. Theophylline and nine derivatives could be determined simultaneously within 40 min. The recovery of these compounds from serum was 95-103%. The linearity (1.0-50 micrograms/ml theophylline) and reproducibility (coefficient of variation less than 2.0%) were sufficient for drug monitoring at the lower and upper limits of therapeutic concentrations of theophylline.

Automated determination of drugs in serum by liquid chromatography with column-switching. I. Separation of antiepileptic drugs and metabolites

This is a fully automated system for determining six common antiepileptic drugs and two principal metabolites of carbamazepine in serum. It is based on "high-performance" liquid chromatography (HPLC), with column switching. TSKprecolumn BSA-ODS and TSKgel ODS-120A (both from Toyo Soda) were used as the precolumn and analytical column, respectively. The former contains octadecylsilyl resins treated with bovine serum albumin (BSA), and does not adsorb macromolecules such as serum proteins but retains small lipophilic molecules such as antiepileptic drugs. Serum samples are directly injected onto the precolumn. After washing out the serum proteins from the precolumn with sodium phosphate buffer, we switch the column connections to introduce the retained substances onto the analytical column and elute with a step-gradient of acetonitrile/sodium phosphate buffer. The high analytical recovery (95-102%) and the reproducibilities (CV less than 5% within-run) indicate that this system is suitable for use in theraputic drug monitoring in clinical laboratories.

Automated determination of drugs in serum by liquid chromatography with column-switching. I. Separation of antiepileptic drugs and metabolites

This is a fully automated system for determining six common antiepileptic drugs and two principal metabolites of carbamazepine in serum. It is based on "high-performance" liquid chromatography (HPLC), with column switching. TSKprecolumn BSA-ODS and TSKgel ODS-120A (both from Toyo Soda) were used as the precolumn and analytical column, respectively. The former contains octadecylsilyl resins treated with bovine serum albumin (BSA), and does not adsorb macromolecules such as serum proteins but retains small lipophilic molecules such as antiepileptic drugs. Serum samples are directly injected onto the precolumn. After washing out the serum proteins from the precolumn with sodium phosphate buffer, we switch the column connections to introduce the retained substances onto the analytical column and elute with a step-gradient of acetonitrile/sodium phosphate buffer. The high analytical recovery (95-102%) and the reproducibilities (CV less than 5% within-run) indicate that this system is suitable for use in theraputic drug monitoring in clinical laboratories.

Effects of acupuncture anesthesia on the pituitary gland

The skin pain threshold was elevated significantly by weak and nonstressful acupuncture stimulation. Although an analgesic effect was obtained by acupuncture stimulation, the beta-E, ACTH, GH and TSH levels were not changed. These findings indicate that these hormone levels were not necessarily related to the skin pain threshold elevation. It is concluded therefore that an analgesic effect was induced without involving the pituitary gland by the weak acupuncture stimulation employed in our study. However, the magnitude of the stimulation may determine whether or not an analgesic effect is mediated by the pituitary gland. The possibility remains that strong acupuncture stimulation produces stress-induced analgesia (SIA). Further detailed research should be attempted.

Detection of platelet consumption in aortic graft with 111In-labeled platelets

Increased platelet consumption in two patients with aortic graft was detected by scintiphotography using 111In-labeled autologous platelets. There was shortened platelet survival time in these patients. These findings might suggest that platelet consumption in aortic prosthesis is related to thrombogenesis.