1.Roles of metabotropic glutamate receptor 5 in low Mg2+ o -inducedinterictal epileptiform activity in rat hippocampal slices
Ji Seon YANG ; Hyun-Jong JANG ; Ki-Wug SUNG ; Duck-Joo RHIE ; Shin Hee YOON
The Korean Journal of Physiology and Pharmacology 2024;28(5):413-422
Group I metabotropic glutamate receptors (mGluRs) modulate postsynaptic neuronal excitability and epileptogenesis. We investigated roles of group I mGluRs on low extracellular Mg2+ concentration ([Mg2+ ]o )-induced epileptiform activity and neuronal cell death in the CA1 regions of isolated rat hippocampal slices without the entorhinal cortex using extracellular recording and propidium iodide staining. Exposure to Mg2+ -free artificial cerebrospinal fluid can induce interictal epileptiform activity in the CA1 regions of rat hippocampal slices. MPEP, a mGluR 5 antagonist, significantly inhibited the spike firing of the low [Mg2+ ]o -induced epileptiform activity, whereas LY367385, a mGluR1 antagonist, did not. DHPG, a group 1 mGluR agonist, significantly increased the spike firing of the epileptiform activity.U73122, a PLC inhibitor, inhibited the spike firing. Thapsigargin, an ER Ca2+ -ATPase antagonist, significantly inhibited the spike firing and amplitude of the epileptiform activity. Both the IP 3 receptor antagonist 2-APB and the ryanodine receptor antagonist dantrolene significantly inhibited the spike firing. The PKC inhibitors such as chelerythrine and GF109203X, significantly increased the spike firing. Flufenamic acid, a relatively specific TRPC 1, 4, 5 channel antagonist, significantly inhibited the spike firing, whereas SKF96365, a relatively non-specific TRPC channel antagonist, did not.MPEP significantly decreased low [Mg2+ ] o DMEM-induced neuronal cell death in the CA1 regions, but LY367385 did not. We suggest that mGluR 5 is involved in low [Mg2+ ]o -induced interictal epileptiform activity in the CA1 regions of rat hippocampal slices through PLC, release of Ca2+ from intracellular stores and PKC and TRPC channels, which could be involved in neuronal cell death.
2.Roles of metabotropic glutamate receptor 5 in low Mg2+ o -inducedinterictal epileptiform activity in rat hippocampal slices
Ji Seon YANG ; Hyun-Jong JANG ; Ki-Wug SUNG ; Duck-Joo RHIE ; Shin Hee YOON
The Korean Journal of Physiology and Pharmacology 2024;28(5):413-422
Group I metabotropic glutamate receptors (mGluRs) modulate postsynaptic neuronal excitability and epileptogenesis. We investigated roles of group I mGluRs on low extracellular Mg2+ concentration ([Mg2+ ]o )-induced epileptiform activity and neuronal cell death in the CA1 regions of isolated rat hippocampal slices without the entorhinal cortex using extracellular recording and propidium iodide staining. Exposure to Mg2+ -free artificial cerebrospinal fluid can induce interictal epileptiform activity in the CA1 regions of rat hippocampal slices. MPEP, a mGluR 5 antagonist, significantly inhibited the spike firing of the low [Mg2+ ]o -induced epileptiform activity, whereas LY367385, a mGluR1 antagonist, did not. DHPG, a group 1 mGluR agonist, significantly increased the spike firing of the epileptiform activity.U73122, a PLC inhibitor, inhibited the spike firing. Thapsigargin, an ER Ca2+ -ATPase antagonist, significantly inhibited the spike firing and amplitude of the epileptiform activity. Both the IP 3 receptor antagonist 2-APB and the ryanodine receptor antagonist dantrolene significantly inhibited the spike firing. The PKC inhibitors such as chelerythrine and GF109203X, significantly increased the spike firing. Flufenamic acid, a relatively specific TRPC 1, 4, 5 channel antagonist, significantly inhibited the spike firing, whereas SKF96365, a relatively non-specific TRPC channel antagonist, did not.MPEP significantly decreased low [Mg2+ ] o DMEM-induced neuronal cell death in the CA1 regions, but LY367385 did not. We suggest that mGluR 5 is involved in low [Mg2+ ]o -induced interictal epileptiform activity in the CA1 regions of rat hippocampal slices through PLC, release of Ca2+ from intracellular stores and PKC and TRPC channels, which could be involved in neuronal cell death.
3.Roles of metabotropic glutamate receptor 5 in low Mg2+ o -inducedinterictal epileptiform activity in rat hippocampal slices
Ji Seon YANG ; Hyun-Jong JANG ; Ki-Wug SUNG ; Duck-Joo RHIE ; Shin Hee YOON
The Korean Journal of Physiology and Pharmacology 2024;28(5):413-422
Group I metabotropic glutamate receptors (mGluRs) modulate postsynaptic neuronal excitability and epileptogenesis. We investigated roles of group I mGluRs on low extracellular Mg2+ concentration ([Mg2+ ]o )-induced epileptiform activity and neuronal cell death in the CA1 regions of isolated rat hippocampal slices without the entorhinal cortex using extracellular recording and propidium iodide staining. Exposure to Mg2+ -free artificial cerebrospinal fluid can induce interictal epileptiform activity in the CA1 regions of rat hippocampal slices. MPEP, a mGluR 5 antagonist, significantly inhibited the spike firing of the low [Mg2+ ]o -induced epileptiform activity, whereas LY367385, a mGluR1 antagonist, did not. DHPG, a group 1 mGluR agonist, significantly increased the spike firing of the epileptiform activity.U73122, a PLC inhibitor, inhibited the spike firing. Thapsigargin, an ER Ca2+ -ATPase antagonist, significantly inhibited the spike firing and amplitude of the epileptiform activity. Both the IP 3 receptor antagonist 2-APB and the ryanodine receptor antagonist dantrolene significantly inhibited the spike firing. The PKC inhibitors such as chelerythrine and GF109203X, significantly increased the spike firing. Flufenamic acid, a relatively specific TRPC 1, 4, 5 channel antagonist, significantly inhibited the spike firing, whereas SKF96365, a relatively non-specific TRPC channel antagonist, did not.MPEP significantly decreased low [Mg2+ ] o DMEM-induced neuronal cell death in the CA1 regions, but LY367385 did not. We suggest that mGluR 5 is involved in low [Mg2+ ]o -induced interictal epileptiform activity in the CA1 regions of rat hippocampal slices through PLC, release of Ca2+ from intracellular stores and PKC and TRPC channels, which could be involved in neuronal cell death.
4.Roles of metabotropic glutamate receptor 5 in low Mg2+ o -inducedinterictal epileptiform activity in rat hippocampal slices
Ji Seon YANG ; Hyun-Jong JANG ; Ki-Wug SUNG ; Duck-Joo RHIE ; Shin Hee YOON
The Korean Journal of Physiology and Pharmacology 2024;28(5):413-422
Group I metabotropic glutamate receptors (mGluRs) modulate postsynaptic neuronal excitability and epileptogenesis. We investigated roles of group I mGluRs on low extracellular Mg2+ concentration ([Mg2+ ]o )-induced epileptiform activity and neuronal cell death in the CA1 regions of isolated rat hippocampal slices without the entorhinal cortex using extracellular recording and propidium iodide staining. Exposure to Mg2+ -free artificial cerebrospinal fluid can induce interictal epileptiform activity in the CA1 regions of rat hippocampal slices. MPEP, a mGluR 5 antagonist, significantly inhibited the spike firing of the low [Mg2+ ]o -induced epileptiform activity, whereas LY367385, a mGluR1 antagonist, did not. DHPG, a group 1 mGluR agonist, significantly increased the spike firing of the epileptiform activity.U73122, a PLC inhibitor, inhibited the spike firing. Thapsigargin, an ER Ca2+ -ATPase antagonist, significantly inhibited the spike firing and amplitude of the epileptiform activity. Both the IP 3 receptor antagonist 2-APB and the ryanodine receptor antagonist dantrolene significantly inhibited the spike firing. The PKC inhibitors such as chelerythrine and GF109203X, significantly increased the spike firing. Flufenamic acid, a relatively specific TRPC 1, 4, 5 channel antagonist, significantly inhibited the spike firing, whereas SKF96365, a relatively non-specific TRPC channel antagonist, did not.MPEP significantly decreased low [Mg2+ ] o DMEM-induced neuronal cell death in the CA1 regions, but LY367385 did not. We suggest that mGluR 5 is involved in low [Mg2+ ]o -induced interictal epileptiform activity in the CA1 regions of rat hippocampal slices through PLC, release of Ca2+ from intracellular stores and PKC and TRPC channels, which could be involved in neuronal cell death.
5.Roles of metabotropic glutamate receptor 5 in low Mg2+ o -inducedinterictal epileptiform activity in rat hippocampal slices
Ji Seon YANG ; Hyun-Jong JANG ; Ki-Wug SUNG ; Duck-Joo RHIE ; Shin Hee YOON
The Korean Journal of Physiology and Pharmacology 2024;28(5):413-422
Group I metabotropic glutamate receptors (mGluRs) modulate postsynaptic neuronal excitability and epileptogenesis. We investigated roles of group I mGluRs on low extracellular Mg2+ concentration ([Mg2+ ]o )-induced epileptiform activity and neuronal cell death in the CA1 regions of isolated rat hippocampal slices without the entorhinal cortex using extracellular recording and propidium iodide staining. Exposure to Mg2+ -free artificial cerebrospinal fluid can induce interictal epileptiform activity in the CA1 regions of rat hippocampal slices. MPEP, a mGluR 5 antagonist, significantly inhibited the spike firing of the low [Mg2+ ]o -induced epileptiform activity, whereas LY367385, a mGluR1 antagonist, did not. DHPG, a group 1 mGluR agonist, significantly increased the spike firing of the epileptiform activity.U73122, a PLC inhibitor, inhibited the spike firing. Thapsigargin, an ER Ca2+ -ATPase antagonist, significantly inhibited the spike firing and amplitude of the epileptiform activity. Both the IP 3 receptor antagonist 2-APB and the ryanodine receptor antagonist dantrolene significantly inhibited the spike firing. The PKC inhibitors such as chelerythrine and GF109203X, significantly increased the spike firing. Flufenamic acid, a relatively specific TRPC 1, 4, 5 channel antagonist, significantly inhibited the spike firing, whereas SKF96365, a relatively non-specific TRPC channel antagonist, did not.MPEP significantly decreased low [Mg2+ ] o DMEM-induced neuronal cell death in the CA1 regions, but LY367385 did not. We suggest that mGluR 5 is involved in low [Mg2+ ]o -induced interictal epileptiform activity in the CA1 regions of rat hippocampal slices through PLC, release of Ca2+ from intracellular stores and PKC and TRPC channels, which could be involved in neuronal cell death.
6.Effect of prophylactic abdominal drainage on postoperative pain in laparoscopic hemicolectomy for colon cancer: a single-center observational study in Korea
Sung Seo HWANG ; Heung-Kwon OH ; Hye-Rim SHIN ; Tae-Gyun LEE ; Mi Jeong CHOI ; Min Hyeong JO ; Hong-min AHN ; Hyeonjeong PARK ; Hyun Hee SIM ; Eunjeong JI ; Anuj Naresh SINGHI ; Duck-Woo KIM ; Sung-Bum KANG
Journal of Minimally Invasive Surgery 2024;27(2):76-84
Purpose:
This study aimed to evaluate the effect of prophylactic abdominal drainage (AD) in laparoscopic hemicolectomy, focusing on assessing postoperative pain outcomes.
Methods:
Patients were categorized into two groups: those with and without AD (AD group vs.no-AD group). A numerical rating scale (NRS) was used to assess postoperative pain on each postoperative day (POD). Further, the inverse probability of treatment weighting (IPTW) method was used to reduce intergroup bias.
Results:
In total, 204 patients who underwent laparoscopic hemicolectomies by a single surgeon between June 2013 and September 2022 at a single institution were retrospectively reviewed. After adjusting for IPTW, NRS scores on POD 2 were significantly lower in the no-AD group (3.2 ± 0.8 vs. 3.4 ± 0.8, p = 0.043). Further examination of postoperative outcomes showed no statistically significant differences in complications between the AD (17.3%) and no-AD (12.4%) groups (p = 0.170). The postoperative length of hospital stay was 7.3 ± 2.8 days in the AD group and 6.9 ± 3.0 days in the no-AD group, with no significant difference (p = 0.298). Time to first flatus was 3.0 ± 0.9 days in the AD group and 2.7 ± 0.9 days in the no-AD group, with no significant difference (p = 0.078). Regarding readmission within 1 month, there were four cases each in the AD (2.3%) and no-AD (1.7%) groups, with no significant difference (p = 0.733).
Conclusion
Laparoscopic hemicolectomy without AD resulted in no significant differences in postoperative clinical outcomes, except for postoperative pain. This finding suggests that prophylactic AD may exacerbate postoperative pain.
7.Treatment Results of Treatment-naïve Neovascular Age-related Macular Degeneration in Patients Over 85 Years of Age
Ji Min KWON ; Sung Soo HWANG ; Jong Wook BANG ; Hyun Woong KIM ; Jae Wan LIM ; Sang Joon LEE ; Dong Geun KIM ; Hyun Duck KWAK ; Kang Yeun PAK
Journal of the Korean Ophthalmological Society 2023;64(9):777-783
Purpose:
To investigate the characteristics and treatment results of patients aged ≥ 85 years who were diagnosed with treatment-naïve neovascular age-related macular degeneration (nAMD).
Methods:
The medical records of patients diagnosed with treatment-naïve nAMD who were ≥ 85 years old at the time of diagnosis with at least 12 months follow-up were retrospectively reviewed. The number of intravitreal injections of anti-vascular endothelial growth factor (VEGF) and agents used during the entire period were investigated. Best-corrected visual acuity and optical coherence tomography results before and after treatment were analyzed. Visual acuity of the fellow eye was also collected.
Results:
A total of 40 eyes of 40 patients with mean age of 87.5 ± 2.4 were included in the study. The mean logarithm of the minimal angle of resolution visual acuity was 0.85 ± 0.57, and the mean of the fellow eye was 0.93 ± 0.99. Compared to before the treatment, there was no significant difference after intravitreal injection in terms of visual acuity. Central retinal thickness showed significant reduction at all time points after treatment.
Conclusions
In patients aged ≥ 85 years at the time of diagnosis, intravitreal injections of anti-VEGF prevented deterioration of visual acuity and showed successful anatomical outcomes. Especially, many had poor visual acuity in the fellow eye, suggesting the importance of maintaining visual acuity. Therefore, active treatment is necessary in the elderly.
8.Universal Screening for Lynch Syndrome Compared with Pedigree-Based Screening: 10-Year Experience in a Tertiary Hospital
Min Hyun KIM ; Duck-Woo KIM ; Hye Seung LEE ; Su Kyung BANG ; Soo Hyun SEO ; Kyung Un PARK ; Heung-Kwon OH ; Sung-Bum KANG
Cancer Research and Treatment 2023;55(1):179-188
Purpose:
Universal screening for Lynch syndrome (LS) refers to routine tumor testing for microsatellite instability (MSI) among all patients with colorectal cancer (CRC). Despite its widespread adoption, real-world data on the yield is lacking in Korean population. We studied the yield of adopting universal screening for LS in comparison with pedigree-based screening in a tertiary center.
Materials and Methods:
CRC patients from 2007-2018 were reviewed. Family histories were obtained and were evaluated for hereditary nonpolyposis colorectal cancer (HNPCC) using Amsterdam II criteria. Tumor testing for MSI began in 2007 and genetic testing was offered using all available clinicopathologic data. Yield of genetic testing for LS was compared for each approach and step.
Results:
Of the 5,520 patients, tumor testing was performed in 4,701 patients (85.2%) and family histories were obtained from 4,241 patients (76.8%). Hereditary CRC (LS or HNPCC) was present in 69 patients (1.3%). MSI-high was present in 6.9%, and 25 patients had confirmed LS. Genetic testing was performed in 41.2% (47/114) of MSI-high patients, out of which 40.4% (19/47) were diagnosed with LS. There were six additional LS patients found outside of tumor testing. For pedigree-based screening, Amsterdam II criteria diagnosed 55 patients with HNPCC. Fifteen of these patients underwent genetic testing, and 11 (73.3%) were diagnosed with LS. Two patients without prior family history were diagnosed with LS and relied solely on tumor testing results.
Conclusion
Despite widespread adoption of routine tumor testing for MSI, this is not a fail-safe approach to screen all LS patients. Obtaining a thorough family history in combination with universal screening provides a more comprehensive ‘universal’ screening method for LS.
9.Analysis of Basic Medicine-Related Questions in the Korean Medical Licensing Examination (2016–2018)
Hyun KOOK ; Sae-Ock OH ; Duck-Joo RHIE ; Sun-Ho KEE ; Yong-Sung JUHNN
Korean Medical Education Review 2023;25(1):68-77
Basic medical education is important for developing the competencies of medical doctors, and it includes basic biomedical sciences, preventive medicine, medical ethics, and clinical science. This study aimed to reveal the current status of the Korean Medical Licensing Examination (KMLE) regarding its evaluation of competencies in basic biomedical sciences. The basic science-related questions were screened and selected from the test forms of the KMLE (2016–2018) by personnel conducting basic biomedical science education, and the selected questions were evaluated with three independent groups of undergraduate students at Chonnam National University Medical School in terms of the learning outcomes of basic medical education. The study scope includes the proportion of basic medicine-related questions, which consist of basic medicine questions and basic medicine-related clinical medicine questions, and its annual change, discipline distribution, and associated learning outcomes. The average proportions of basic biomedical sciences, preventive medicine and medical law, and clinical sciences were 2.3%, 5.8%, and 91.9% of all questions, respectively. The proportion of basic medicine-related questions, except those on preventive medicine and medical law, was 22.0% of the total, and questions on pharmacology and microbiology accounted for 83.0% of the basic medicine-related questions. The proportion of sub-enabling learning outcomes linked with basic medicine-related questions comprised 14.0% of the total outcomes for basic biomedical sciences and 30.4% for preventive medicine and medical law. It is concluded that the KMLE questions may not sufficiently cover the essential competencies of basic medical education for medical doctors, and the KMLE may need to be improved with regard to competencies in basic biomedical sciences.
10.Association between microsatellite instability and tumor response to neoadjuvant chemoradiotherapy for rectal cancer
Soo Young LEE ; Duck-Woo KIM ; Jaram LEE ; Hyeong-min PARK ; Chang Hyun KIM ; Kyung-Hwa LEE ; Heung-Kwon OH ; Sung-Bum KANG ; Hyeong Rok KIM
Annals of Surgical Treatment and Research 2022;103(3):176-182
Purpose:
The relationship between microsatellite instability (MSI) and tumor response after neoadjuvant chemoradiotherapy (nCRT) in rectal cancer remains unclear. The present study aimed to evaluate the association between MSI and tumor response to nCRT in rectal cancer treatment.
Methods:
Patients with rectal cancer from 2 tertiary hospitals who underwent nCRT, followed by radical surgery, were included. The microsatellite status was determined using a PCR-based Bethesda panel. Tumors with a Dworak’s tumor regression grade of 3 or 4 were considered to have a good response. Predictive factors for a good response to nCRT were analyzed.
Results:
Of the 1,401 patients included, 910 (65.0%) had MSI results and 1.5% (14 of 910) showed MSI-H. Among all the patients, 519 (37.0%) showed a good response to nCRT. A univariate analysis showed that MSI-H tended to be negatively associated with a good response to nCRT, but no statistical significance was observed (7.1% vs. 24.1%, P = 0.208).Multivariate analysis showed that well-differentiated tumors were the only predictive factor for good response to nCRT (odds ratio [OR], 2.241; 95% confidence interval [CI], 1.492–3.364; P < 0.001). MSI status tended to be associated with the response to nCRT (OR, 0.215; 95% CI, 0.027–1.681; P = 0.143).
Conclusion
MSI-H was not associated with response to nCRT in patients with rectal cancer.

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