• Molecular & Cellular Toxicology
• /
• v.2 no.3
• /
• pp.216-221
• /
• 2006

The cholinesterase-inhibiting organophosphorous (OP) compounds known as nerve agents are highly toxic. The principal toxic mechanism of OP compounds is the inhibition of acethylcholine esterase (AChE) by phosphorylation of its catalytic site. The reversible competitive inhibition of AChE may prevent the subsequent OP intoxication. In this study, three-dimensional quantitative structure-activity relationship (3D-QSAR) was performed to investigate the relationship between the 29 compounds with structural diversity and their bioactivities against AChE. In particular, predictive models were constructed using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). The results indicate reasonable model for CoMFA ($q^{2}=0.453,\;r^{2}=0.697$) and CoMSIA ($q^{2}=0.518,\;r^{2}=0.696$). The presence of steric and hydophobic group at naphtyl moiety of the model may lead to the design of improved competitive inhibitors for organophosphorous intoxication.

• The Korean journal of internal medicine
• /
• v.33 no.6
• /
• pp.1058-1069
• /
• 2018

Neuropathic cancer pain (NCP) is caused by nerve damage attributable to the cancer per se, and/or treatments including chemotherapy, radiotherapy, and surgery; the prevalence is reported to be as high as 40%. The etiologies of NCP include direct nerve invasion or nerve compression by the cancer, neural toxicity, chemotherapy, and radiotherapy. NCP is subdivided into plexopathy, radiculopathy, and peripheral neuropathies, among several other categories. The clinical characteristics of NCP differ from those of nociceptive pain in terms of both the hypersensitivity symptoms (burning, tingling, and an electrical sensation) and the hyposensitivity symptoms (numbness and muscle weakness). Recovery requires several months to years, even after recovery from injury. Management is complex; NCP does not usually respond to opioids, although treatments may feature both opioids and adjuvant drugs including antidepressants, anticonvulsants, and anti-arrhythmic agents, all of which improve the quality-of-life. This review addresses the pathophysiology, clinical characteristics and management of NCP, and factors rendering pain control difficult.

• The Korean Journal of Pain
• /
• v.19 no.2
• /
• pp.292-295
• /
• 2006

The diagnosis of chronic abdominal pain due to abdominal cutaneous nerve entrapment can be elusive. Tenderness in patients with abdominal pain is naturally assumed to be of either peritoneal or visceral origin. Studies have shown that some patients suffer from prolonged pain in the abdominal wall and are often misdiagnosed, even after unnecessary and expensive diagnostic tests, including potentially dangerous invasive procedures, and treated as having a visceral source for their complaints, even in the presence of negative X-ray findings and atypical symptoms. Abdominal cutaneous nerve entrapment syndrome is rarely diagnosed, which is possibly due to failure to recognize the condition rather than the lack of occurrence. The accepted treatment for abdominal cutaneous nerve entrapment syndrome is a local injection, with infiltration of anesthetic agents coupled with steroids. Careful history taking and physical examination, in conjunction with the use of trigger zone injections, can advocate the diagnosis of abdominal cutaneous nerve entrapment and preclude any unnecessary workup of these patients. Herein, 3 cases of abdominal cutaneous nerve entrapment syndrome, which were successfully treated with local anesthetics and steroid, are reported.

• The Korean Journal of Pain
• /
• v.33 no.3
• /
• pp.208-215
• /
• 2020

Zoster sine herpete (ZSH) is one of the atypical clinical manifestations of herpes zoster (HZ), which stems from infection and reactivation of the varicella-zoster virus (VZV) in the cranial nerve, spinal nerve, viscera, or autonomic nerve. Patients with ZSH display variable symptoms, such as neuralgia, however, different from HZ, ZSH show no zoster, which makes clinical diagnosis difficult. ZSH not only causes initial symptoms, such as neuropathic pain in the affected nerve, Bell palsy, and Ramsay Hunt syndrome, but also postherpetic neuralgia and fatal complications such as VZV encephalitis and stroke. The misdiagnosis of ZSH and tardy antiviral treatment may lead to severe ZSH sequelae. We review the publications related to ZSH, especially its diagnosis with VZV DNA and/or anti-VZV immunoglobulin (IgG and IgM). More work about ZSH, especially ZSH epidemiological survey and guidelines for its diagnosis and treatment, are needed because most of the present studies are case reports.

• The Korean Journal of Pain
• /
• v.14 no.1
• /
• pp.83-92
• /
• 2001

Background: This study was undertaken to observe the functional changes of the hind limb and histopathological changes in the sciatic nerve after an injection of alcohol or phenol, which are commonly used neurolytic agents, highlighting the time of recovery. Methods: Forty-eight Sprague-Dawley rats weighing 200-300 g were used for the experiment. Histopathological changes under the electron microscope, were observed in the distal part of the sciatic nerve, into which 0.1 ml of alcohol or phenol was injected. This was severed in 3 rats of each group at 10 minutes, 1 hour, 24 hours, 3 days, 1, 2, 4 and 6 weeks later. The functional changes in the hind limbs were observed for 6 weeks by noting their walking pattern. Results: Following the injection of alcohol or phenol into the right sciatic nerve, the right hind limb showed a severe pronounced motor weakness and obvious gait changes. About 2 weeks later, gradual improvement of gait changes began, and after 6 weeks, the motor weakness and gait changes were no longer perceptible in both groups. The findings of any histopathological change were similar in both alcohol or phenol groups. At 10 minutes after injection, destructive lesions were confined to the unmyelinated fibers and the myelin sheath of small the myelinated fibers. On the 3rd day and at 1 week, pathologic changes in axonal fibers and Schwann cells were in being phagocytized in spite of myelin restitution. From 2 to 4 weeks, axonal regeneration and remyelination appeared at the same time a myelin disintegration and axonolysis. At 6 weeks, neural regeneration was similar to that of the contralateral control group. Conclusions: These results suggest that functional and histopathological changes, after injection of neurolytics into the peripheral nerves, are quite similar in both alcohol and phenol groups. The progression of functional and histopathological changes become more obvious according to the time interval following the injection. Consequently, side effects that develop following the use of alcohol or phenol may begin to improve around the time that nerve regeneration occurs, i.e., two to four weeks later.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.2 no.1
• /
• pp.73-81
• /
• 1999

Four bis-iodosobenzoic acid derivatives have been synthesizd in 5 steps following literature methods from 5-hydroxyantranilic acid; 1) diazotization and iodination, 2) acid protection, 3) tosylate substitution, 4) acid deprotection, 5) oxidation of iodo-substituent to iodoso group. Catalytic effects of new 5,5'-tri-, tetra-, deca-, polyethyleneglycoxy- bis(2-iodosobenzoic acid) on hydrolysis reactions of PNPDPP(p-nitrophenyl diphenyl phosphate), sarin and soman have been measured to determine the role of ethyleneglycoxy substituents as phase transfer catalysts. At $25{\pm}0.2^{\circ}C$, pH 8.0, and cetyltrimethyl ammonium chloride(CTACl) micelle solution condition, bis-IBA derivatives hydrolyzes PNPDPP with maximum pseudo-first order rate constant($K_{obsd}^{max}$) of 0.32035 ~ 0.13659 $sec^{-1}$, which corresponds to 2~18 times rate increase than those of unsubstituted o-IBA[iodosobenzoate($K_{obsd}^{max}=0.0645sec^{-1}$), iodoxybenzoate ($K_{obsd}^{max}$ = $0.0178 sec^{-1}$)]. At the similar condition for PNPDPP hydrolysis, bis-IBA derivatives also act as efficient catalysts for hydrolytic cleavage of nerve agents such as sarin and soman. Hydrolysis rate constant with 5,5'-polyethyleneglycoxy- bis(2-iodosobenzoic acid) shows 7 times increase than that of simple 5-hydroxy-2-iodosobenzoic acid.

• Journal of The Korean Dental Society of Anesthesiology
• /
• v.13 no.3
• /
• pp.71-79
• /
• 2013

Local pain management is the most critical aspect of patient care in dentistry. Local anesthesia is a reversible blockade of nerve conduction in an applied area that produces loss of sensation. The chemical agents used to produce local anesthesia stabilize neuronal membranes by inhibiting the ionic fluxes required for the propagation of neural impulses. Proper local anesthesia permits the dental surgeon to perform the necessary surgical procedure in a careful, gentle fashion that will be less stressful for both the operator and the patient. The improvements in agents for local anesthesia are probably the most significant advances that have occurred in dental science. Today's anesthetics are safe, effective, and can be administered with insignificant soft tissue damage and minimal concerns for allergic reactions. This article reviews the widely used local anesthetic agents for obtaining local anesthesia, and also discusses some frequently seen complications.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.20 no.3
• /
• pp.173-178
• /
• 2020

We experienced a case of induction of general anesthesia without using neuromuscular blocking agents (NMBAs) in a 40-year-old woman with a history of anaphylaxis immediately after the administration of anesthetics lidocaine, propofol, and rocuronium to perform endoscopic sinus surgery 2 years before. The skin test showed a positive reaction to rocuronium and cis-atracurium. We induced general anesthesia without using NMBAs after inducing airway anesthesia with lidocaine (transtracheal injection and superior laryngeal nerve block). Deep general anesthesia was maintained with end-tidal 4 vol% sevoflurane. Hypotension was treated with phenylephrine infusion. The operation condition was excellent, and patient recovered without complications after surgery. Airway anesthesia with local anesthetics may be helpful when we cannot use NMBAs for any reason, including hypersensitivity to NMBA and surgery that needs neuromuscular monitoring.

• Restorative Dentistry and Endodontics
• /
• v.40 no.2
• /
• pp.155-160
• /
• 2015

Objectives: Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis. Materials and Methods: Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests. Results: At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure. Conclusions: There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment.

• Carbon letters
• /
• v.6 no.3
• /
• pp.158-165
• /
• 2005

Room temperature kinetics of degradation of nerve agent simulants and sarin, an actual nerve agent at the surface of different carbon based adsorbent materials such as active carbon grade 80 CTC, modified whetlerite containing 2.0 and 4.0 % NaOH, active carbon with 4.0 % NaOH, active carbon with 10.0 % Cu (II) ethylenediamine and active carbon with 10.0 % Cu (II) 1,1,1,5,5,5-hexafluoroacetylacetonate were studied. The used adsorbent materials were characterized for surface area and micropore volume by $N_2$ BET. For degradation studies solution of simulants of nerve agent such as dimethyl methylphosphonate (DMMP), diethyl chlorophosphate (DEClP), diethyl cyanophosphate (DECnP) and nerve agent, i.e., sarin in chloroform were prepared and used for the uniform adsorption on the adsorbent systems using their incipient volume at room temperature. Degradation kinetics was monitored by GC/FID and was found to be following pseudo first order reaction. Kinetics parameters such as rate constant and half life were calculated. Half life of degradation with modified whetlerite (MWh/NaOH) system having 4.0 % NaOH was found to be 1.5, 7.9, 1206 and 20 minutes for DECnP, DEClP, DMMP and sarin respectively. MWh/NaOH system showed maximum degradation of simulants of nerve agents and sarin to their hydrolysis products. The reaction products were characterized using NMR technique. MWh/NaOH adsorbent was also found to be active against sulphur mustard.