1.A Case of Pigmented Epidermal Cyst with Dense Collection of Melanin.
Jiyun JUNG ; Minkyung LEE ; Jimin HA ; Eunbyul CHO ; Eunjoo PARK ; Kwangho KIM ; Kwangjoong KIM
Korean Journal of Dermatology 2016;54(9):751-753
No abstract available.
Epidermal Cyst*
;
Melanins*
2.Electrodiagnostic Studies in Neurological Complications of Acute Hemorrhagic Conjunctivitis.
Journal of the Korean Neurological Association 1983;1(1):9-14
Electrodiagnostic studies were carried out in 31 patients with neurological complications of AHC, who were seen at Seoul National University Hospital from August 1981 to February 1982. Age of the patients ranged from 14 to 62 years. Both velocity and distal latency of motor and sensory conduction were normal in the nerves innervating the affected muscles. During the acute phase of motor paralysis, there was an absence of electrical activity in completely paralysed muscles. In partially denervated muscles, there were polyphasic motor unit potentials of normal duration and amplitrde on weak contraction and reduced interference on maximal effort. From the third or fourth week onwards, fibrillation potentials and positive sharp waves at rest were observed in paraspinal muscles in most cases. All the above findings were supporting the view that the principal site of involvement for the paralytic phenomena is at the level of the anterior horn cells or anterior roots.
Anterior Horn Cells
;
Conjunctivitis, Acute Hemorrhagic*
;
Humans
;
Muscles
;
Paralysis
;
Paraspinal Muscles
;
Seoul
3.Chronicles of EGFR Tyrosine Kinase Inhibitors: Targeting EGFR C797S Containing Triple Mutations
Krishna Babu DUGGIRALA ; Yujin LEE ; Kwangho LEE
Biomolecules & Therapeutics 2022;30(1):19-27
Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase widely expressed in many cancers such as non-small cell lung cancer (NSCLC), pancreatic cancer, breast cancer, and head and neck cancer. Mutations such as L858R in exon 21, exon 19 truncation (Del19), exon 20 insertions, and others are responsible for aberrant activation of EGFR in NSCLC. First-generation EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib have clinical benefits for EGFR-sensitive (L858R and Del19) NSCLC patients. However, after 10-12 months of treatment with these inhibitors, a secondary T790M mutation at the gatekeeper position in the kinase domain of EGFR was identified, which limited the clinical benefits. Second-generation EGFR irreversible inhibitors (afatinib and dacomitinib) were developed to overcome this T790M mutation. However, their lack of selectivity toward wild-type EGFR compromised their clinical benefits due to serious adverse events. Recently developed third-generation irreversible EGFR TKIs (osimertinib and lazertinib) are selective toward driving mutations and the T790M mutation, while sparing wildtype EGFR activity. The latest studies have concluded that their efficacy was also compromised by additional acquired mutations, including C797S, the key residue cysteine that forms covalent bonds with irreversible inhibitors. Because second- and thirdgeneration EGFR TKIs are irreversible inhibitors, they are not effective against C797S containing EGFR triple mutations (Del19/ T790M/C797S and L858R/T790M/C797S). Therefore, there is an urgent unmet medical need to develop next-generation EGFR TKIs that selectively inhibit EGFR triple mutations via a non-irreversible mechanism.
4.Comparison of Conventional Surgical Tracheostomy and Percutaneous Dilatational Tracheostomy in the Neurosurgical Intensive Care Unit
Sungdae LIM ; Hyun PARK ; Ja Myoung LEE ; Kwangho LEE ; Won HEO
Korean Journal of Neurotrauma 2022;18(2):246-253
Objective:
Tracheostomy is a necessary procedure for patients admitted to the neurosurgery intensive care unit (ICU) with severe brain injury, because mechanical ventilation must be maintained for a long time following neurologic failure. The purpose of this study was to compare conventional surgical tracheostomy (CST) and percutaneous dilatational tracheostomy (PDT) performed at the bedside in critically ill neurosurgery patients requiring tracheostomy to determine which procedure has comparative advantages.
Methods:
This retprospective study was conducted between January 2019 and December 2020. PDT was performed on 52 patients and CST was performed on 44 patients. The baseline characteristics, procedural characteristics, and clinical outcomes were recorded.
Results:
The mean operative time in the CST group was 25.5±6.5 minutes and that in the PDT group was 15.1±2.5 minutes; the difference was statistically significant (p<0.01). Four patients in the CST group and none in the PDT group experienced bleeding requiring transfusion. However, there was no significant difference in total ICU mortality or length of hospital stay. There were no statistical differences in the individual complication categories between the 2 study groups.
Conclusion
There were fewer procedure-induced complications among patients receiving PDT than among those receiving CST. In addition, the treatment time for PDT was shorter than that for CST treatment.
5.Analysis of temperature-dependent abnormal bursting patterns of neurons in Aplysia
Nam Gyu HYUN ; Kwangho HYUN ; Saecheol OH ; Kyungmin LEE
The Korean Journal of Physiology and Pharmacology 2020;24(4):349-362
Temperature affects the firing pattern and electrical activity of neurons in animals, eliciting diverse responses depending on neuronal cell type. However, the mechanisms underlying such diverse responses are not well understood. In the present study, we performed in vitro recording of abdominal ganglia cells of Aplysia juliana , and analyzed their burst firing patterns. We identified atypical bursting patterns dependent on temperature that were totally different from classical bursting patterns observed in R15 neurons of A. juliana . We classified these abnormal bursting patterns into type 1 and type 2; type 1 abnormal single bursts are composed of two kinds of spikes with a long interspike interval (ISI) followed by short ISI regular firing, while type 2 abnormal single bursts are composed of complex multiplets. To investigate the mechanism underlying the temperature dependence of abnormal bursting, we employed simulations using a modified Plant model and determined that the temperature dependence of type 2 abnormal bursting is related to temperaturedependent scaling factors and activation or inactivation of potassium or sodium channels.
6.Analysis of temperature-dependent abnormal bursting patterns of neurons in Aplysia
Nam Gyu HYUN ; Kwangho HYUN ; Saecheol OH ; Kyungmin LEE
The Korean Journal of Physiology and Pharmacology 2020;24(4):349-362
Temperature affects the firing pattern and electrical activity of neurons in animals, eliciting diverse responses depending on neuronal cell type. However, the mechanisms underlying such diverse responses are not well understood. In the present study, we performed in vitro recording of abdominal ganglia cells of Aplysia juliana , and analyzed their burst firing patterns. We identified atypical bursting patterns dependent on temperature that were totally different from classical bursting patterns observed in R15 neurons of A. juliana . We classified these abnormal bursting patterns into type 1 and type 2; type 1 abnormal single bursts are composed of two kinds of spikes with a long interspike interval (ISI) followed by short ISI regular firing, while type 2 abnormal single bursts are composed of complex multiplets. To investigate the mechanism underlying the temperature dependence of abnormal bursting, we employed simulations using a modified Plant model and determined that the temperature dependence of type 2 abnormal bursting is related to temperaturedependent scaling factors and activation or inactivation of potassium or sodium channels.
7.Redomicrofracture as a Treatment for Osteochondral Lesion of Talus after the Failure of Arthroscopic Microfracture.
Woo Jin CHOI ; Kwang Hwan PARK ; Moses LEE ; Kwangho CHUNG ; Jin Woo LEE
Journal of Korean Foot and Ankle Society 2015;19(2):43-46
Arthroscopic treatment has been reported to provide effective improvement of ankle function when used in treatment of small osteochondral lesion of talus; however, favorable long-term results have been less predictable for large osteochondral lesion of talus. In cases in which primary arthroscopic treatment fails, the decision regarding which subsequent technique to choose has become increasingly difficult, as good clinical outcomes may be unlikely for such patients irrespective of the surgical technique used. Redomicrofracture should be used judiciously for treatment of osteochondral lesion of talus in which arthroscopic treatment has failed.
Ankle
;
Humans
;
Talus*
8.Persistent Primitive Trigeminal Artery That Mimics Persistent Primitive Otic Artery on Cerebral Angiography.
Kwangho LEE ; Hyun PARK ; Insung PARK ; Jongwoo HAN
Journal of Cerebrovascular and Endovascular Neurosurgery 2016;18(2):120-123
Persistent primitive trigeminal artery (PPTA) is the most common carotid-basilar anastomosis; on the other hand, persistent primitive otic artery (PPOA) is extremely rare. PPTA is often misdiagnosed as PPOA on cerebral angiography. We present a case of PPTA that mimicked PPOA on cerebral angiography. We further describe the utility of brain computed tomography angiography for differential diagnosis of PPTA from PPOA, together with a review of previous literature.
Angiography
;
Arteries*
;
Brain
;
Central Nervous System Vascular Malformations
;
Cerebral Angiography*
;
Diagnosis, Differential
;
Hand
9.Ultrasonographic evaluation of tracheal collapse in dogs.
Kidong EOM ; Kumjung MOON ; Yunsang SEONG ; Taeho OH ; Sungjoon YI ; Keunwoo LEE ; Kwangho JANG
Journal of Veterinary Science 2008;9(4):401-405
Tracheal ultrasonography was performed to measure the width of the tracheal ring shadow and to assess the clinical relevance of these measurements for identifying tracheal collapse. The first tracheal ring width (FTRW) and thoracic inlet tracheal ring width (TITRW) were measured on both expiration and inspiration. The mean of the FTRW width (129 dogs) was greater in expiration (10.97 +/- 1.02 mm, p = 0.001) than that in inspiration (9.86 +/- 1.03 mm). For 51 normal dogs, the mean of the TITRW width was greater in expiration (9.05 +/- 1.52 mm, p = 0.001) than in inspiration (8.02 +/- 1.43 mm). For 78 tracheal collapse dogs, the mean of the TITRW width was greater in expiration (15.89 +/- 1.01 mm, p = 0.001) than in inspiration (14.85 +/- 1.17 mm). The TITRW/FTRW ratio of the normal dogs was higher (p = 0.001) in expiration (0.81 +/- 0.09) than that in inspiration (0.79 +/- 0.10). When compared between the normal and tracheal collapse dogs, the TITRW/FTRW ratio was also increased (p = 0.001) both in expiration (1.54 +/- 0.09) and inspiration (1.47 +/- 0.08), respectively. Based on these results, the cutoff level of the TITRW/FTRW ratio was statistically analyzed according to the receiver operating characteristic curve and it could be set at 1.16 in expiration and at 1.13 in inspiration. We have demonstrated that tracheal ultrasonography is a useful technique for the evaluation of tracheal collapse and it can be a supportive tool together with the radiographic findings for making the correct diagnosis.
Animals
;
Dog Diseases/diagnosis/pathology/*ultrasonography
;
Dogs
;
Female
;
Male
;
Radiography, Thoracic/*veterinary
;
Sensitivity and Specificity
;
Trachea/*pathology/radiography
;
Tracheal Stenosis/diagnosis/pathology/veterinary
10.Stent-Assisted Coil Embolization Using Only a Glycoprotein IIb/IIIa Inhibitor (Tirofiban) for Ruptured Wide-Necked Aneurysm Repair.
Sang Hyub LEE ; In Sung PARK ; Ja Myoung LEE ; Kwangho LEE ; Hyun PARK ; Chul Hee LEE
Journal of Cerebrovascular and Endovascular Neurosurgery 2018;20(1):14-23
OBJECTIVE: The aim of this study was to evaluate the safety and efficacy of stent-assisted coil embolization using only a glycoprotein IIb/IIIa inhibitor (tirofiban). MATERIALS AND METHODS: We retrospectively reviewed patients with a subarachnoid hemorrhage due to ruptured wide-necked intracranial aneurysms who were treated by stent-assisted coil embolization. In all patients, the glycoprotein IIb/IIIa inhibitor tirofiban was administered just before stent deployment. Electronic medical records for these patients were reviewed for peri-procedural complications and extra-ventricular drainage catheter related hemorrhage, as well as Glasgow outcome scale (GOS) at discharge, 3 months, and 6 months follow-up were recorded. RESULTS: Fifty-one aneurysms in 50 patients were treated. The mean patient age was 64.9 years. Eighteen patients (36%) received a World Federation of Neurosurgical Societies grade of 4 or 5. The mean aneurysm size was 9.48 mm and mean dome-to-neck ratio was 1.06. No intraoperative aneurysm ruptures occurred, although five (10%) episodes of asymptomatic stent thrombosis did occur. Three patients experienced a delayed thrombo-embolic event and two a delayed hemorrhagic event. Immediate radiologic assessment indicated a complete occlusion in 29 patients, a residual neck in 19, and a residual sac in 3. Four patients (8%) died. Sixteen patients (32%) experienced a poor GOS (< 4). Two aneurysms were recanalized during the follow-up period (mean, 19 months for clinical and 18 months for angiographic follow-up). CONCLUSION: Treatment of ruptured wide-necked intracranial aneurysms via stent-assisted coil embolization with a glycoprotein IIb/IIIa inhibitor alone was found to be relatively safe and efficient.
Aneurysm*
;
Catheters
;
Drainage
;
Electronic Health Records
;
Embolization, Therapeutic*
;
Endovascular Procedures
;
Follow-Up Studies
;
Glasgow Outcome Scale
;
Glycoproteins*
;
Hemorrhage
;
Humans
;
Intracranial Aneurysm
;
Neck
;
Platelet Aggregation Inhibitors
;
Retrospective Studies
;
Rupture
;
Stents
;
Subarachnoid Hemorrhage
;
Thrombosis