BACKGROUND: A mixture of local anesthetics such as lidocaine and bupivacaine has frequently been used in clinical practice. The rationale behind this is to take advantage of lidocaine's rapid onset and bupivacaine's perpetuation in anesthesia. The purpose of this study was to examine the changes in the onset and recovery of nerve blocking action exerted by the different combinations of these two in the mixture. METHODS: Isolated sciatic nerve preparations obtained from adult male Sprague-Dawley rats were used in this study. Recordings of A-fiber compound action potentials (A-CAPs) were made at the end of the isolated nerve while single pulse stimuli (0.5 msec, supramaximal intensity, 2 Hz) were applied to the opposite end of the nerve. Seven different composition of lidocaine-bupivacaine mixtures were prepared (0 : 6, 1 : 5, 2 : 4, 3 : 3, 4 : 2, 5 : 1, 6 : 0 vol./vol.), where basal concentrations of lidocaine and bupivacaine were 0.2% and 0.05%, respectively. Amplitudes of A-CAPs were measured before, during and after perfusion of mixture solution. The time needed for A-CAPs amplitude to decrease to 10% of the basal value after starting perfusion (onset time) and that needed to reach to 50% of the basal value after ceasing the perfusion (recovery time) were measured. RESULTS: With increasing concentration ratios of lidocaine to bupivacaine in the mixture as mentioned above, the following onset and recovery times were obtained (6.0 +/- 0.3, 5.6 +/- 0.3, 6.0 +/- 0.5, 8.3 +/- 0.5, 7.3 +/- 0.6, 7.8 +/- 0.3, and 10.8 +/- 0.8, minutes; 38 +/- 4, 63 +/- 12, 87 +/- 19, 100 +/- 13, 104 +/- 18, 137 +/- 27, and 157 +/- 18 minutes, respectively). CONCLUSION: Onset times were, in general, exponentially decreased with the increase in the lidocaine concentration. However, recovery times were lineary increased with the increase in the bupivacaine concentration. So, it should be kept in mind that rapid onset can only be obtained with the expense of substantial reduction in the duration of local anesthetic effect of the mixture, and vice versa.
Action Potentials ; Adult ; Anesthesia ; Anesthetics ; Anesthetics, Local ; Bupivacaine ; Humans ; Lidocaine ; Male ; Nerve Block ; Neural Conduction* ; Perfusion ; Rats, Sprague-Dawley ; Sciatic Nerve

No abstract available.
Aging ; Animals ; Cerebral Cortex* ; Neurons* ; Neuropeptide Y* ; Neuropeptides* ; Nitric Oxide Synthase* ; Nitric Oxide* ; Rats*

In order to study the relationship between clinical group of cervical spondylosis and electrical activity, we traced somatosensory evoked potential(SSEP) by stimulating the median nerve(MN) from the upper extremities, and the posterior tibial nerve(PTN) from the lower extremities simultaneously. The purpose of this study was to test the clinical diagnostic utility of the method, whether any consistent relationship exists between the severity and type of neurological symptoms and the results of the SSEP responses, and between neurological improved patients after operation and improved SSEP results. In this study patients were clinically divided into three groups : combined myelopathy and radiculopathy, myelopathy alone, radiculopathy alone. Over a 3-year period from 1987 to 1989, SSEP were performed on 112 patients of Korean adults and summary of the results obtained are as follows : 1) Among patients with cervical spondylosis, those with cervical myelopathy showed more abnormal SSEP than those cervical radiculopathy. 2) In the group with myelopathy, MN-cervical latensy, Ep-C2 interpeak latency. PTN-P1 latency, and N1 latency were prolonged more than MN-C2 latency, Ep-C2 interpeak latency, PTN-P1 latency, and N1 latency of the group with radiculopathy. 3) The longer the duration of the symptoms, the more abnormal were the SSEP in patients with cervical spondylosis. 4) In patient with cervical myelopathy, the latency of SSEP was prolonged not only in those with sensory deficit, but also with motor deficit. 5) Half of clinically improved patients after operation showed improved SSEP in follow-up examinations. 6) Improvement in SSEP after operation was much affected by posterior approach.
Adult ; Evoked Potentials, Somatosensory* ; Follow-Up Studies ; Humans ; Lower Extremity ; Radiculopathy ; Spinal Cord Diseases ; Spondylosis* ; Upper Extremity

No abstract available.
Animals ; Calcium* ; Clonidine* ; Ganglia, Spinal* ; Rats* ; Spinal Nerve Roots* ; Tetracaine*

Ectopic meningioma is a rare disease. Three cases of ectopic meningioma, which were located in the diploic space of cranial vaults and orbital roof, is reported. Intradiploic meningiomas may be considered a subgroup of the intraosseous mininiomas. Nomencolature and histrogenesis of this type of meningioma are discussed. And also pathological features and diagnosis are discussed in an attemp to idenify characteristics of these ectopic meningiomas.
Diagnosis ; Meningioma* ; Orbit ; Rare Diseases

Ectopic meningioma is a rare disease. Three cases of ectopic meningioma, which were located in the diploic space of cranial vaults and orbital roof, is reported. Intradiploic meningiomas may be considered a subgroup of the intraosseous mininiomas. Nomencolature and histrogenesis of this type of meningioma are discussed. And also pathological features and diagnosis are discussed in an attemp to idenify characteristics of these ectopic meningiomas.
Diagnosis ; Meningioma* ; Orbit ; Rare Diseases

BACKGROUND: Dextromethorphan (DEX) is an NMDA receptor antagonist which has recently been introduced for the treatment of chronic pain mainly to reduce the central sensitization component of pain. It is also reported to reduce the pain from acute ischemia of an extremity in a rat model which has a similar mechanism as tourniquet pain. The purpose of this experiment was to see if dextromethorphan could reduce tourniquet pain in normal volunteers. METHODS: A double blind randomized cross-over test was done on ten healthy male volunteers. Each subject was orally administered with three different doses of DEX (placebo, 30, 60 mg) 1 h before the study according to a preallocated randomized table. The subject was not reallocated for the test within two weeks of the previous test. After a 10 minute acclimation period before each test, the degree of tourniquet pain measured by VAS, arterial blood pressure, heart rate, respiration rate, and pressure-evoked pain were measured before and every 5 minutes after inflation of the tourniquet until the subject felt unbearable pain. A mixed model for repeated measurement of data was used for statistical analysis (P < 0.05). RESULTS: There was no statistical difference between different doses of DEX including the placebo. Rather, there was a tendency that DEX increases the pain. And there also was a tendency that average time to reach unbearable pain was decreased by DEX (P > 0.05). CONCLUSIONS: DEX is not effective in controlling tourniquet pain in normal awake subjects.
Acclimatization ; Arterial Pressure ; Central Nervous System Sensitization ; Chronic Pain ; Dextromethorphan* ; Extremities ; Healthy Volunteers* ; Heart Rate ; Humans ; Inflation, Economic ; Ischemia ; Male ; Models, Animal ; N-Methylaspartate ; Respiratory Rate ; Tourniquets* ; Volunteers

BACKGROUND: The addition of epinephrine to local anesthetics has been known to prolong the duration of neural blokade and to increase the intensity of analgesia, but underlying mechanisms are unclear. This study was designed to investigate electrophysiologically the analgesic effects of epinephrine and its interaction with tetracaine. METHODS: Whole cell patch clamp recordings were made from acutely dissociated neurons from adult rat dorsal root ganglion (DRG). Using voltage clamp method, we compared the IC50 values of tetracaine for Na+ and Ca2+ channel suppression in the absence and presence of a fixed dose of epinephrine. Action potentials evoked by current pulses were also investigated to evaluate the effect of tetracaine and epinephrine on the excitability of DRG neurons. RESULTS: Clinical doses of epinephrine did not alter the dose-response curves of tetracaine for peak Na+ and Ca2+ channel current, but the amplitude of action potential spikes was reduced and firing rates evoked by sustained current pulse increased. The addition of epinephrine did not affect the changes of action potential parameters caused by tetracaine alone. CONCLUSIONS: The ability of epinephrine to increase the intensity of analgesia induced by tetracaine seems more likely due to an analgesic action at the level of spinal cord rather than a direct analgesic action at a level of primary sensory neurons. Local vasoconstriction and stimulation of descending inhibitory system via alpha-adrenergic pathway may play a role.
Action Potentials ; Adult ; Analgesia ; Anesthetics, Local ; Animals ; Diagnosis-Related Groups ; Epinephrine* ; Fires ; Ganglia, Spinal* ; Humans ; Inhibitory Concentration 50 ; Neurons ; Rats ; Sensory Receptor Cells ; Spinal Cord ; Spinal Nerve Roots* ; Tetracaine* ; Vasoconstriction

PURPOSE: To investigate the association between long-term exposure to ambient air pollution and lung cancer incidence in Koreans. MATERIALS AND METHODS: This was a population-based case-control study covering 908 lung cancer patients and 908 controls selected from a random sample of people within each Korean province and matched according to age, sex, and smoking status. We developed land-use regression models to estimate annual residential exposure to particulate matter (PM₁₀) and nitrogen dioxide (NO₂) over a 20-year exposure period. Logistic regression was used to estimate odds ratios (ORs) and their corresponding 95% confidence intervals (CI). RESULTS: Increases in lung cancer incidence (expressed as adjusted OR) were 1.09 (95% CI: 0.96−1.23) with a ten-unit increase in PM₁₀ (µg/m³) and 1.10 (95% CI: 1.00−1.22) with a ten-unit increase in NO₂ (ppb). Tendencies for stronger associations between air pollution and lung cancer incidence were noted among never smokers, among those with low fruit consumption, and among those with a higher education level. Air pollution was more strongly associated with squamous cell and small cell carcinomas than with adenocarcinoma of the lung. CONCLUSION: This study provides evidence that PM₁₀ and NO₂ contribute to lung cancer incidence in Korea.
Adenocarcinoma ; Air Pollution* ; Carcinoma, Small Cell ; Case-Control Studies* ; Education ; Epithelial Cells ; Fruit ; Humans ; Incidence ; Korea ; Logistic Models ; Lung Neoplasms* ; Lung* ; Nitrogen Dioxide ; Odds Ratio ; Particulate Matter ; Smoke ; Smoking

Insulin autoimmune syndrome is characterized by spontaneous hypoglycemia, high concentrations of serum immunoreactive insulin, and the presence of autoantibodies to insulin without previous insulin injection. A 71-year-old woman with diabetes, who had been treated with oral hypoglycemic agents, suffered from frequent hypoglycemia. High insulin levels and the presence of insulin autoantibodies were shown, so insulin autoimmune syndrome was diagnosed. Drugs containing sulfhydryl groups play an important role in the pathogenesis of insulin autoimmune syndrome. Alpha-lipoic acid, which contains a sulfhydryl group, was administered before the onset of hypoglycemia. The patient's human leukocyte antigen (HLA) type was HLA-Cw4 and DRB1*0406. There is a strong correlation between HLA-DRB1*0406 and insulin autoimmune syndrome. The patient was treated with prednisolone and has not had a hypoglycemic attack since. We report a case of insulin autoimmune syndrome, possibly associated with alpha-lipoic acid.
Aged ; Autoantibodies ; Female ; HLA-C Antigens ; HLA-DRB1 Chains ; Humans ; Hypoglycemia ; Hypoglycemic Agents ; Insulin ; Leukocytes ; Prednisolone ; Thioctic Acid