1.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.
2.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.
3.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.
4.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
5.ischVascular Calcification in Patients Undergoing Total Knee Arthroplasty: Frequency and Effects on the Surgery
Ju-Hyung YOO ; Jin-Gyu KIM ; Kwangho CHUNG ; Seung Hyun LEE ; Hyun-Cheol OH ; Sang-Hoon PARK ; Sang-Ok SEOK
Clinics in Orthopedic Surgery 2020;12(2):171-177
Background:
This study aims to investigate the frequency of distal femoral and popliteal arterial calcification and to evaluate the intraoperative and postoperative effects of arterial calcification in patients undergoing total knee arthroplasty using a tourniquet.
Methods:
The records of 5,438 patients who had undergone primary total knee arthroplasty between January 2003 and January 2017 were retrospectively reviewed. We examined the preoperative radiographs of the knee from all patients for calcifications of the femoral and popliteal arteries. Vascular calcification was identified on preoperative radiographs in 223 cases. Intraoperative and postoperative complications were investigated among these patients. Postoperative complications were analyzed from the time of surgery to the last follow-up (minimum 1-year follow-up).
Results:
Vascular calcification of the arteries around the knee was found in 223 cases (4.1%). The mean patient age was 70.6 years in the non-calcification group and 73.8 years in the calcification group (p > 0.05). The calcification group was classified into medial, intimal, or mixed subgroups according to the morphology of calcification on preoperative radiographs. The medial type included 46 cases (20.6%); intimal type, 161 cases (72.2%); and mixed type, 16 cases (2.7%). There was no statistically significant difference in demographic and surgical data among the three groups. There were intraoperative complications in two cases in the medial type group, both of which involved tourniquet failure. There was also a postoperative complication in one case in the medial type group, which involved wound dehiscence at 2 weeks postoperatively. No other postoperative complications were identified during 1-year follow-up.
Conclusions
Despite the presence of calcifications in the arteries around the knee, total knee arthroplasty (using a tourniquet) can be performed without serious complications.
6.Laparoscopic Splenectomy for a Patient with Splenomegaly and Hypersplenism due to Idiopathic Portal Hypertension.
Kwangho YANG ; Sung Pil YUN ; Jae Hun KIM ; Dae Hwan KIM ; Hyun Sung KIM ; Hyung Il SEO
Journal of Minimally Invasive Surgery 2017;20(3):113-116
Idiopathic portal hypertension (IPH) is a rare disorder which is clinically characterized by portal hypertension, splenomegaly, hypersplenism and the absence of liver cirrhosis. Patients with IPH have massive splenomegaly leading to increased portal venous flow and subsequent portal hypertension. In selected IPH patients with splenomegaly and hypersplenism, splenectomy can be regarded as an effective treatment protocol for decreasing portal hypertension. We report a case of a 44-year-old woman who was diagnosed with IPH accompanied by splenomegaly and hypersplenism. She underwent laparoscopic splenectomy and clinical symptoms and hypersplenism resolved. Our study shows that laparoscopic splenectomy can be considered as a procedure for treating patients with splenomegaly and hypersplenism due to IPH.
Adult
;
Clinical Protocols
;
Female
;
Humans
;
Hypersplenism*
;
Hypertension, Portal*
;
Liver Cirrhosis
;
Splenectomy*
;
Splenomegaly*
7.Y-configuration Stent-assisted Coil Embolization for Wide-necked Intracranial Bifurcation Aneurysms.
Kwangho LEE ; Hyun PARK ; Insung PARK ; Sukh Que PARK ; O Ki KWON ; Jongwoo HAN
Journal of Cerebrovascular and Endovascular Neurosurgery 2016;18(4):355-362
OBJECTIVE: The objective of this study was to determine the efficiency and safety of Y configuration stent-assisted coiling with double-closed stents for wide-necked intracranial aneurysms located at arterial bifurcations thorough analysis of a multicenter case series. MATERIALS AND METHODS: A retrospective chart review was done on 10 patients who underwent endovascular treatment of wide-necked intracranial aneurysms with Y-configuration stent-assisted coil embolization in three centers from August 2011 to March 2014. The degree of aneurysmal occlusion was assessed using the Raymond scale. Clinical outcomes were assessed before operation, at discharge, and at the last follow-up visit using the Glasgow outcome scale. RESULTS: The 10 patients included 6 females and 4 males with a mean age of 58.6 years. Indications for treatment included 6 unruptured intracranial aneurysms and 4 ruptured intracranial aneurysms. Five aneurysms were located at the basilar artery bifurcation, four aneurysms were located in an anterior communicating artery, and one aneurysm was in the pericallosal artery. The mean size of the 10 aneurysms was 9.7 mm. All aneurysms had a dome-to-neck ratio of < 1.5 (mean, 0.89). Immediate complications included one thromboembolic event out of the 10 cases. Immediate posttreatment angiograms showed complete occlusion in 1 aneurysm and residual necks in 9 aneurysms. Follow-up results showed 8 complete occlusions and 2 residual necks. No delayed complications were observed during the follow-up period (mean: 20 months). CONCLUSION: Y configuration using double-closed cell stents is feasible and safe in selected patients. This method is an acceptable option for managing complex wide-necked bifurcations.
Aneurysm*
;
Arteries
;
Basilar Artery
;
Embolization, Therapeutic*
;
Female
;
Follow-Up Studies
;
Glasgow Outcome Scale
;
Humans
;
Intracranial Aneurysm
;
Male
;
Methods
;
Neck
;
Retrospective Studies
;
Stents
8.Clinical Impacts of Donor Types of Living vs. Deceased Donors: Predictors of One-Year Mortality in Patients with Liver Transplantation.
Eun Jung KIM ; Seungjin LIM ; Chong Woo CHU ; Je Ho RYU ; Kwangho YANG ; Young Mok PARK ; Byung Hyun CHOI ; Tae Beom LEE ; Su Jin LEE
Journal of Korean Medical Science 2017;32(8):1258-1262
Transplantation studies about the clinical differences according to the type of donors are mostly conducted in western countries with rare reports from Asians. The aims of this study were to evaluate the clinical impacts of the type of donor, and the predictors of 1-year mortality in patients who underwent liver transplantation (LT). This study was performed for liver transplant recipients between May 2010 and December 2014 at the Pusan National University Yangsan Hospital. A total of 185 recipients who underwent LT were analyzed. Of the 185 recipients, 109 (58.9%) belonged to the living donor liver transplantation (LDLT) group. The median age was 52.4 years. LDLT recipients had lower model for end-stage liver disease (MELD) score compared with better liver function than deceased donor liver transplantation (DDLT) recipients (mean ± standard deviation [SD], 12.5 ± 8.3 vs. 24.9 ± 11.7, respectively; P < 0.001), and had more advanced hepatocellular carcinoma (HCC) (62.4% vs. 21.1%, respectively; P = 0.001). In complications and clinical outcomes, LDLT recipients showed shorter stay in intensive care unit (ICU) (mean ± SD, 10.8 ± 8.8 vs. 23.0 ± 13.8 days, respectively, P < 0.001), ventilator care days, and post-operative admission days, and lower 1-year mortality (11% vs. 27.6%, respectively, P = 0.004). Bleeding and infectious complications were less in LDLT recipients. Recipients with DDLT (P = 0.004) showed higher mortality in univariate analysis, and multi-logistic regression analysis found higher MELD score and higher pre-operative serum brain natriuretic peptide (BNP) were associated with 1-year mortality. This study may guide improved management before and after LT from donor selection to post-operation follow up.
Asian Continental Ancestry Group
;
Busan
;
Carcinoma, Hepatocellular
;
Donor Selection
;
Follow-Up Studies
;
Gyeongsangnam-do
;
Hemorrhage
;
Humans
;
Intensive Care Units
;
Liver Diseases
;
Liver Transplantation*
;
Liver*
;
Living Donors
;
Mortality*
;
Natriuretic Peptide, Brain
;
Tissue Donors*
;
Transplant Recipients
;
Ventilators, Mechanical
9.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
10.Predictors of postoperative infectious complications in liver transplant recipients: experience of 185 consecutive cases.
Seungjin LIM ; Eun Jung KIM ; Tae Beom LEE ; Byung Hyun CHOI ; Young Mok PARK ; Kwangho YANG ; Je Ho RYU ; Chong Woo CHU ; Su Jin LEE
The Korean Journal of Internal Medicine 2018;33(4):798-806
BACKGROUND/AIMS: Infections following liver transplant (LT) remain a major cause of mortality. This study was conducted to evaluate risk factors for infection and to review clinical characteristics. METHODS: Medical records of patients who underwent LT from 2010 to 2014 were retrospectively analyzed. Binary logistic regression analysis was used to investigate risk factors of infection. Kaplan-Meier analysis was used to predict prognosis of infected and non-infected groups. RESULTS: Of 185 recipients, 89 patients experienced infectious complications. The median follow-up period was 911 days (range, 9 to 2,031). The infected group had higher 1-year mortality (n = 22 [24.7%] vs. n = 8, [8.3%], p = 0.002), and longer postoperative admission days (mean: 53.7 ± 35.8 days vs. 28.3 ± 13.0 days, p < 0.001), compared to the non-infected group. High preoperative Model for End-Stage Liver Disease (MELD) score (odds ratio [OR], 1.057; 95% confidence interval [CI], 1.010 to 1.105; p = 0.016), deceased-donor type (OR, 5.475; 95% CI, 2.442 to 12.279; p < 0.001), and acute rejection (OR, 3.042; 95% CI, 1.241 to 7.454; p = 0.015) were independent risk factors associated with infection. Intra-abdominal infection (n = 35, 20.8%) was the major infectious complication. Among identified bacteria, Enterococcus species (28.4%) were major pathogens, followed by Escherichia coli and Klebsiella species. CONCLUSIONS: High preoperative MELD score, deceased-donor type, and acute rejection were risk factors associated with infection. To prevent infections following surgery, it is important to determine the appropriate time of operation before the recipient has a high MELD score.
Bacteria
;
Enterococcus
;
Escherichia coli
;
Follow-Up Studies
;
Humans
;
Intraabdominal Infections
;
Kaplan-Meier Estimate
;
Klebsiella
;
Liver Diseases
;
Liver Transplantation
;
Liver*
;
Logistic Models
;
Medical Records
;
Mortality
;
Prognosis
;
Retrospective Studies
;
Risk Factors
;
Transplant Recipients*