• The Korean Journal of Physiology and Pharmacology
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• v.27 no.5
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• pp.481-491
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• 2023

The β subunits of high voltage-gated calcium channels (HGCCs) are essential for optimal channel functions such as channel gating, activation-inactivation kinetics, and trafficking to the membrane. In this study, we report for the first time the potent blood pressure-reducing effects of peptide fragments derived from the β subunits in anesthetized and non-anesthetized rats. Intravenous administration of 16-mer peptide fragments derived from the interacting regions of the β1 [cacb1(344-359)], β2 [cacb2(392-407)], β3 [cacb3(292-307)], and β4 [cacb4(333-348)] subunits with the main α-subunit of HGCC decreased arterial blood pressure in a dose-dependent manner for 5-8 min in anesthetized rats. In contrast, the peptides had no effect on the peak amplitudes of voltage-activated Ca²⁺ current upon their intracellular application into the acutely isolated trigeminal ganglion neurons. Further, a single mutated peptide of cacb1(344-359)-cacb1(344-359)_K357R-showed consistent and potent effects and was crippled by a two-amino acid-truncation at the N-terminal or C-terminal end. By conjugating palmitic acid with the second amino acid (lysine) of cacb1(344-359)_K357R (named K2-palm), we extended the blood pressure reduction to several hours without losing potency. This prolonged effect on the arterial blood pressure was also observed in non-anesthetized rats. On the other hand, the intrathecal administration of acetylated and amidated cacb1(344-359)_K357R peptide did not change acute nociceptive responses induced by the intradermal formalin injection in the plantar surface of rat hindpaw. Overall, these findings will be useful for developing antihypertensives.

• Korean Journal of Transplantation
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• v.28 no.3
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• pp.165-168
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• 2014

The recipient candidate was a 51-year-old male with end-stage renal disease owing to diabetes mellitus. The initial immunosuppressive regimen included basiliximab for induction and tacrolimus, mycophenolate mofetil, and steroids. Urine output was 413 mL/day on the operative day and 100 mL/day on the postoperative day (POD) 1. There was no definite stenosis of the ureter or vessels. He had anuria on POD 2~4 and he had undergone hemodialysis. His serum creatinine level did not decrease. Therefore, a graft biopsy was performed on POD 4. The pathologic finding was consistent with acute calcineurin inhibitor (CNI) toxicity. There was no evidence of rejection or acute tubular necrosis. Anuria continued on POD 6; therefore, we started sirolimus instead of a CNI based regimen. Graft function was gradually recovered 1 day after reduction of CNI dose and hemodialysis was stopped. The serum creatinine level was normalized on POD 10. He was discharged on POD 21.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3854-3859
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• 2023

Background: This study aims to develop an evaluator that can quickly and accurately evaluate the shielding of low-energy industrial radiation generators. Methods: We used PyQt to develop a graphical user interface (GUI)-based program and employed the calculation methodology reported in the National Council on Radiation Protection and Measurements (NCRP)-49 for shielding calculations. We gathered the necessary factors for shielding evaluation using two libraries designed for Python, pandas and NumPy, and processed them into a database. We verified the effectiveness of the proposed program by comparing the results with those from safety reports of six domestic facilities. Results: After verifying the effectiveness of the program using the NCRP-49 example, we obtained an average error rate of 1.73%. When comparing the facility safety report and results obtained using the program, we found that the error rate was between 1.09% and 6.51%. However, facilities that did not use a defined shielding methodology were underestimated by 31.82% compared with the program (the final barrier thickness satisfied the shielding standard). Conclusion: The developed program provides a fast and accurate shielding evaluation that can assist personnel that work in radiation generator facilities and government officials in reviewing safety.

• Pediatric Infection and Vaccine
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• v.30 no.3
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• pp.180-187
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• 2023

In Korea, >90% of children and adolescents aged <19 years have been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) since 2020. Among confirmed cases of pediatric coronavirus disease 2019 (COVID-19), 40-60% of patients developed neurologic symptoms such as seizures, headache, and encephalitis. Herein, we report the case of a 3-year-old female patient with SARS-CoV-2 infection who presented with seizures and altered consciousness and was diagnosed with COVID-19 encephalitis. The patient recovered after treatment with intravenous immunoglobulin, high-dose steroids, anti-seizure drugs, and an anti-viral agent. She was discharged after regaining the ability to speak words and walk alone on hospital day 39. Complete recovery was observed at the 1-year follow-up. The findings in this case suggest that early detection and active intervention is associated with better outcomes in patients with COVID-19 encephalitis.

• Clinical and Experimental Vaccine Research
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• v.13 no.1
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• pp.42-53
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• 2024

Purpose: Conduct a systematic review of case reports and case series regarding the development of acute abdomen following coronavirus disease 2019 (COVID-19) vaccination, to describe the possible association and the clinical and demographic characteristics in detail. Materials and Methods: This study included case report studies and case series that focused on the development of acute abdomen following COVID-19 vaccination. Systematic review studies, literature, letters to the editor, brief comments, and so forth were excluded. PubMed, Scopus, EMBASE, and Web of Science databases were searched until June 15, 2023. The Joanna Briggs Institute tool was used to assess the risk of bias and the quality of the study. Descriptive data were presented as frequency, median, mean, and standard deviation. Results: Seventeen clinical case studies were identified, evaluating 17 patients with acute abdomen associated with COVID-19 vaccination, which included acute appendicitis (n=3), acute pancreatitis (n=9), diverticulitis (n=1), cholecystitis (n=2), and colitis (n=2). The COVID-19 vaccine most commonly linked to acute abdomen was Pfizer-BioNTech (messenger RNA), accounting for 64.71% of cases. Acute abdomen predominantly occurred after the first vaccine dose (52.94%). All patients responded objectively to medical (88.34%) and surgical (11.76%) treatment and were discharged within a few weeks. No cases of death were reported. Conclusion: Acute abdomen is a rare complication of great interest in the medical and surgical practice of COVID-19 vaccination. Our study is based on a small sample of patients; therefore, it is recommended to conduct future observational studies to fully elucidate the underlying mechanisms of this association.

• The Korean journal of internal medicine
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• v.39 no.1
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• pp.123-136
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• 2024

Background/Aims: Despite short-acting β₂-agonist (SABA) overuse being associated with poor asthma outcomes, data on SABA use in South Korea is scarce. Herein, we describe prescription patterns of SABA and other asthma medications in patients from the South Korean cohort of the SABA use IN Asthma (SABINA) III study. Methods: This study included patients with asthma aged ≥ 12 years, who had ≥ 3 consultations with the same healthcare provider, and medical records containing data for ≥ 12 months prior to the study visit. Patients were classified by investigator-defined asthma severity (per 2017 Global Initiative for Asthma recommendations) and practice type (primary or specialist care). Data on disease characteristics, asthma treatments, and clinical outcomes in the 12 months before the study visit were collected using electronic case report forms. Results: Data from 476 patients (mean age, 55.4 years; female, 63.0%) were analyzed. Most patients were treated by specialists (83.7%) and had moderate-to-severe asthma (91.0%). Overall, 7.6% of patients were prescribed ≥ 3 SABA canisters (defined as over-prescription). In patients prescribed SABA in addition to maintenance therapy, 47.4% were over-prescribed SABA. Most patients (95.4%) were prescribed a fixed-dose combination of an inhaled corticosteroid and a long-acting β₂-agonist as maintenance therapy. Although asthma was well-controlled/partly-controlled in 91.6% of patients, 29.6% experienced ≥ 1 severe asthma exacerbation. Conclusions: SABA over-prescription was reported in nearly 50% of patients prescribed SABA in addition to maintenance therapy, underscoring the need to align clinical practices with the latest evidence-based recommendations and educate physicians and patients on appropriate SABA use.

• The Korean Journal of Physiology
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• v.18 no.1
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• pp.19-35
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• 1984

Since the first report of Drury and $Szent-Gy{\ddot{o}}rgyi$ in 1929, the inhibitory influences of adenosine on the heart have repeatedly been described by many investigators. These studies have shown that adenosine and adenine nucleotides have overall depressant effects, similar to those of acetylcholine. Heart beats become slow and weak. It is also well known that adenosine is a potent endogenous coronary vasodilator. Many investigations on the working mechanisms of adenosine have been focused mainly on the effects of the coronary blood flow. However, the cellular mechanisms underlying the inhibitory action of adenosine on sinus node are not well understood yet. Thus, this study was undertaken to examine the behavior of rabbit SA node under influence of adenosine. In these series of experiments three kinds of preparations were used: whole atrial pair, left atrial strip, and isolated SA node preparations. The electrical activity of SA node was recorded with conventional glass microelectrodes 30 to 50 $M{\Omega}$. The preparations were superfused with bicarbonate-buffered Tyrode solution of pH 7.35 and aerated with a gas mixture of $3%\;CO_2-97%\;O_2$ at $35^{\circ}C$. In whole atrial pair, adenosine suppressed sinoatrial rhythm in a dose-dependent manner. Effect of adenosine on atrial rate appeared at the concentration of $10^{-5}M$ and was enhanced in parallel with the increase in adenosine concentration. Inhibitory action of adenosine on pacemaker activity was more prominent in the preparation pretreated with norepinephrine, which can steepen the slope of pacemaker potential by increasing permeability of $Ca^{+2}$. Calcium ions in perfusate slowly produced a marked change in sinoatrial rhythm. Elevation of the calcium concentration from 0.3 to 8 mM increased the atrial rate from 132 to 174 beats/min, but over 10 mM $Ca^{+2}$ decreased. The inhibitory effect of adenosine on sinoatrial rhythm developed very rapidly. Atrial rate was recovered promptly from the adenosine-induced suppression by the addition of norepinephrine, but extra $Ca^{+2}$ was less suitable to restore the suppression of atrial rate. Adenosine suppressed also atrial contractility in the same dosage range that restricted pacemaker activity, even in the reserpinized preparation. In isolated SA node preparation, spontaneous firing rate of SA node at $35^{\circ}C$(mean{\pm}SEM, n=16) was $154{\pm}3.3\;beats/min. The parameters of action potentials were: maximum diastolic potential(MDP), $-73{\pm}1.7\;mV: overshoot(OS), $9{\pm}1.4\;mV: slope of pacemaker potential(SPP), $94{\pm}3.0\;mV/sec. Adenosine suppressed the firing rate of SA node in a dose-dependent manner. This inhibitory effect appeared at the concentration of $10^{-6}M$ and was in parallel with the increase in adenosine concentration. Changes in action potential by adenosine were dose-dependent increase of MDP and decrease of SPP until $10^{-4}M$. Above this concentration, however, the amplitude of action potential decreased markedly due to the simultaneous decrease of both MDP and OS. All these effects of adenosine were not affected by pretreatment of atropine and propranolol. Lowering extra $Ca^{2+}$ irom 2 mM to 0.3 mM resulted in a marked decrease of OS and SPP, but almost no change of MDP. However, increase of perfusate $Ca^{2+}$ from 2 mM to 6 or 8 mM produced a prominent decrease of MDP and a slight increase of OS and SPP. Dipyridamole(DPM), which is known to block the adenosine transport across the cell membrane, definately potentiated the action of adenosine. The results of this experiment suggest that adenosine suppressed pacemaker activity and atrial contractility simultaneously and directly, by decreasing $Ca^{2+}-permeability$ of nodal and atrial cell membranes.

• Progress in Medical Physics
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• v.8 no.2
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• pp.3-17
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• 1997

Because a wedged beam consists of attenuated primary photons and scattered radiations from wedge, the spectrum of the wedged beam does not coincide with that of an open beam with same geometry. The aims of current report are to get exact information about whether effects of 15-60$^{\circ}$ wedge for 4 -10 MV photon beams should be considered for dose calculation or not, and to suggest a reference condition for measurement of wedge transmission factor. Percent depth dose of both open and wedged fields with angles of 15, 30, 45, 60$^{\circ}$ for beams of 4 MV(Clinac 4/100, Varian), two 6 MV(Clinac 6/100 and Clinac 2100C, Varian), 10 MV(Clinac 2100C, Varian) X-rays were measured to 30cm deep in water using ionization chambers. Hardening factors of photon beams were calculated with measured PDDs. Both field size factors and transmission factors of wedge filters were measured at d$_{max}$ in water. Beam hardening factors of wedged fields of 4 and 6 MV X-ray were larger than 1 for all wedge angles, field sizes and depths deeper than d$_{max}$ Beam hardening factors for wedge angles 15, 30, 45, 60$^{\circ}$ for 10$\times$10cm were respectively 1.010, 1.014, 1.023 and 1.034 for 4MV X-ray, 1.005, 1.008, 1.019, and 1.024 for 6MV X-ray of Clinac 6/100, 1.011, 1.021, 1.032, 1.036 for 6MV X-ray of Clinac 2100C, and 1.008, 1.012, 1.012 and 1.012 for 10MV X-ray. Beam hardening factors of 10MV X-ray were 1 within 1.2％ difference for all wedge angles, depths and field sizes. It was made clear that for 6MV X-rays, the beam hardening factor depends on treatment machine. The relationship of the factor and depth was linear. Field size factor at d$_{max}$ was independent of wedge angle except for the field of 15$\times$15cm. and maximum difference of the field size factors for the field size was 1.4％ for 4MV X-ray. When the wedge factor is determined, dependence of the factor on field size is negligible at d$_{max}$ but should be considered at deeper depth. Calculating dose distribution or MU, the beam hardening factor should be applied for 4~6MV X-ray beams, but might not be considered for 10MV beam. When wedge transmission factor was determined at d$_{max}$ or in air, field size factors for open field are also applicable to wedged fields, but otherwise, field size factor for each wedge or wedge factor depending on field size should be applied.

• Radiation Oncology Journal
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• v.25 no.2
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• pp.79-92
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• 2007

[ $\underline{Purpose}$ ]: For the first time, a nationwide survey in the Republic of Korea was conducted to determine the basic parameters for the treatment of esophageal cancer and to offer a solid cooperative system for the Korean Pattern of Care Study database. $\underline{Materials\;and\;Methods}$: During $1998{\sim}1999$, biopsy-confirmed 246 esophageal cancer patients that received radiotherapy were enrolled from 23 different institutions in South Korea. Random sampling was based on power allocation method. Patient parameters and specific information regarding tumor characteristics and treatment methods were collected and registered through the web based PCS system. The data was analyzed by the use of the Chi-squared test. $\underline{Results}$: The median age of the collected patients was 62 years. The male to female ratio was about 91 to 9 with an absolute male predominance. The performance status ranged from ECOG 0 to 1 in 82.5% of the patients. Diagnostic procedures included an esophagogram (228 patients, 92.7%), endoscopy (226 patients, 91.9%), and a chest CT scan (238 patients, 96.7%). Squamous cell carcinoma was diagnosed in 96.3% of the patients; mid-thoracic esophageal cancer was most prevalent (110 patients, 44.7%) and 135 patients presented with clinical stage III disease. Fifty seven patients received radiotherapy alone and 37 patients received surgery with adjuvant postoperative radiotherapy. Half of the patients (123 patients) received chemotherapy together with RT and 70 patients (56.9%) received it as concurrent chemoradiotherapy. The most frequently used chemotherapeutic agent was a combination of cisplatin and 5-FU. Most patients received radiotherapy either with 6 MV (116 patients, 47.2%) or with 10 MV photons (87 patients, 35.4%). Radiotherapy was delivered through a conventional AP-PA field for 206 patients (83.7%) without using a CT plan and the median delivered dose was 3,600 cGy. The median total dose of postoperative radiotherapy was 5,040 cGy while for the non-operative patients the median total dose was 5,970 cGy. Thirty-four patients received intraluminal brachytherapy with high dose rate Iridium-192. Brachytherapy was delivered with a median dose of 300 cGy in each fraction and was typically delivered $3{\sim}4\;times$. The most frequently encountered complication during the radiotherapy treatment was esophagitis in 155 patients (63.0%). $\underline{Conclusion}$: For the evaluation and treatment of esophageal cancer patients at radiation facilities in Korea, this study will provide guidelines and benchmark data for the solid cooperative systems of the Korean PCS. Although some differences were noted between institutions, there was no major difference in the treatment modalities and RT techniques.

• Radiation Oncology Journal
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• v.28 no.1
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• pp.1-8
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• 2010

Purpose: This retrospective study was performed to evaluate the efficacy of radiation therapy (RT) and to investigate the prognostic factors for thymoma when treated with RT. Materials and Methods: We analyzed 21 patients with thymoma and also received RT from March 2002 to January 2008. The median follow-up time was 37 months (range, 3 to 89 months). The median patient age was 57 years (range, 24 to 77 years) and the gender ratio of males to females was 4：3. Of the 21 patients, complete resections (trans-sternal thymectomy) and R2 resections were performed in 14 and 1 patient, respectively. A biopsy was performed in 6 patients (28.7%). The WHO cell types in the 21 patients were as follows: 1 patient (4.8%) had type A, 10 patients (47.6%) had type B1-3, and 10 patients (47.6%) had type C. Based on Masaoka staging, 10 patients (47.6%) were stage II, 7 patients (33.3%) were stage III, and 4 patients (19.1%) were stage IVa. Three-dimensional RT was adminstered to the tumor volume (planned target volume), including the anterior mediastinum and the residual disease. The total RT dose ranged from 52.0 to 70.2 Gy (median dose, 54 Gy). Consistent with the WHO criteria, the response rate was only analyzed for the 6 patients who received a biopsy only. The prognostic factors analyzed for an estimate of survival included age, gender, tumor size, tumor pathology, Masaoka stage, the possibility of treatment by performing surgery, the presence of myasthenia gravis, and RT dose. Results: The 3-year overall survival rate (OS) and the progression free survival rate (PFS) were 80.7% and 78.2%, respectively. Among the 10 patients with WHO cell type C, 3 of 4 patients (75%) who underwent a complete resection and 3 of 6 patients (50%) who underwent a biopsy survived. Distant metastasis developed in 4 patients (19.1%). The overall response rate in the 6 patients who received biopsy only were as follows: partial remission in 4 patients (66.7%), stable disease in 1 patient (16.6%), and progressive disease in 1 patient (16.6%). Acute RTOG radiation pneumonitis occurred in 1 patient (4.8%), grade 2 occurred in 2 patients (9.5%), grade 3 occurred in 1 patient (4.8%), and grade 4 occurred in 1 patient (4.8%). A univariate analysis revealed that the significant prognostic factors for OS were age (${\geq}60$, 58.3%; <60, 100%; p=0.0194), pathology (WHO cell type A-B3, 100%; C, 58.3%; p=0.0194) and, whether the patient underwent surgery (yes, 93.3%; no, 50%; p=0.0096). Conclusion: For the 15 patients who received surgery, there was no local failure within the radiation field. In patients with WHO cell type C, surgical procedures could have resulted in a more favorable outcome than biopsy alone. We report here our clinical experience in 21 patients with thymoma who were treated by radiation therapy.