This study offers a comprehensive overview of brain organoids for researchers. It combines expert opinions with technical summaries on organoid definitions, characteristics, culture methods, and quality control. This approach aims to enhance the utilization of brain organoids in research. Brain organoids, as three-dimensional human cell models mimicking the nervous system, hold immense promise for studying the human brain. They offer advantages over traditional methods, replicating anatomical structures, physiological features, and complex neuronal networks. Additionally, brain organoids can model nervous system development and interactions between cell types and the microenvironment. By providing a foundation for utilizing the most human-relevant tissue models, this work empowers researchers to overcome limitations of two-dimensional cultures and conduct advanced disease modeling research.

Purpose: This single-arm phase II trial investigate the efficacy and safety of S-1 plus oxaliplatin (SOX) in patients with metastatic breast cancer. Materials and Methods: Patients with metastatic breast cancer previously treated with anthracyclines and taxanes were enrolled. Patients received S-1 (40-60 mg depending on patient’s body surface area, twice a day, day 1-14) and oxaliplatin (130 mg/m2, day 1) in 3 weeks cycle until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumor 1.1. Secondary endpoints included time-to-progression (TTP), duration-of-response (DoR), overall survival (OS), and adverse events. Results: A total of 87 patients were enrolled from 11 institutions in Korea. Hormone receptor was positive in 54 (62.1%) patients and six (6.9%) had human epidermal growth factor receptor 2–positive disease. Forty-eight patients (85.1%) had visceral metastasis and 74 (55.2%) had more than three sites of metastases. The ORR of SOX regimen was 38.5% (95% confidence interval [CI], 26.9 to 50.0) with a median TTP of 6.0 months (95% CI, 5.1 to 6.9). Median DoR and OS were 10.3 months (95% CI, 5.5 to 15.1) and 19.4 (95% CI, not estimated) months, respectively. Grade 3 or 4 neutropenia was reported in 28 patients (32.1%) and thrombocytopenia was observed in 23 patients (26.6%). Conclusion This phase II study showed that SOX regimen is a reasonable option in metastatic breast cancer previously treated with anthracyclines and taxanes.

Background/Aims: This study evaluated the long-term cardiovascular complications among Korean patients with hypertension and compared them with that of controls without hypertension. Methods: The Korean Hypertension Cohort (KHC) enrolled 11,043 patients with hypertension and followed them for more than 10 years. Age- and sex-matched controls without hypertension were enrolled at a 1:10 ratio. We compared the incidence of cardiovascular events and death among patients and controls without hypertension. Results: The mean age was 59 years, and 34.8% and 16.5% of the patients belonged to the high and moderate cardiovascular risk groups, respectively. During the 10-year follow-up, 1,591 cardiovascular events (14.4%) with 588 deaths (5.3%) occurred among patients with hypertension and 7,635 cardiovascular events (6.9%) with 4,826 deaths (4.4%) occurred among controls. Even the low-risk population with hypertension showed a higher cardiovascular event rate than the population without hypertension. Although blood pressure measurements in the clinic showed remarkable inaccuracy compared with those measured in the national health examinations, systolic blood pressure (SBP) ≥ 150 mmHg was significantly associated with a higher risk of cardiovascular events. Conclusions This long-term follow-up study confirmed the cardiovascular event rates among Korean hypertensive patients were substantial, reaching 15% in 10 years. SBP levels ≥ 150 mmHg were highly associated with occurrence of cardiovascular event rates.

Objective: When rescuers move from ambulance to resuscitation area, they press the chest with one-hand by the stretchers. The purpose of this study was to investigate the effect of one-hand chest compression on unfolded stretchers and analyze the characteristics of rescuers that affect compression. Methods: A manikin simulation study was planned. A total of 28 participants performed one-hand chest compression for one minute to a manikin on the unfolded stretchers. The depth of compression, the extent of recoil and compression frequency were measured, and the results were analyzed. Correlation analysis was done between participant characteristics and depth and frequency of compression. Linear regression analysis was done for variables with significant correlation. Results: Four participants were excluded due to wrist or shoulder pain. A total of 24 participants (13 male; 11 female) were enrolled. The mean depth of compression was 34.88±11.06 cm; the mean extent of recoil was 50.00±0 cm. The mean frequency of compression was 104.71±11.07 per minute. The extent of recoil and frequency of compression were satisfied with cardiopulmonary resuscitation (CPR) guidelines. The depth of compression was highly correlated with participants’ sex (r=-0.88), height (r=0.86), and weight (r=0.78). When adjusted for sex, the depth of compression increased as height and weight increased. Conclusion Mechanical chest compression device should be used when CPR is required while moving a cardiac arrest patient by the stretchers. If CPR needs to be done manually, moving distance should be minimized. Finally, a new type of stretcher that fits the body shape of Koreans should be developed.

Background and Objectives: The aim of this study was to demonstrate the efficacy and safety of treatment with drug-coated balloon (DCB) in a large real-world population. Methods: Patients treated with DCBs were included in a multicenter observational registry that enrolled patients from 18 hospitals in Korea between January 2009 and December 2017. The primary outcome was target lesion failure (TLF) defined as a composite of cardiovascular death, target vessel myocardial infarction, and clinically indicated target lesion revascularization at 12 months. Results: The study included 2,509 patients with 2,666 DCB-treated coronary artery lesions (1,688 [63.3%] with in-stent restenosis [ISR] lesions vs. 978 [36.7%] with de novo lesions).The mean age with standard deviation was 65.7±11.3 years; 65.7% of the patients were men.At 12 months, the primary outcome, TLF, occurred in 179 (6.7%), 151 (8.9%), 28 (2.9%) patients among the total, ISR, and de novo lesion populations, respectively. A history of hypertension, diabetes, acute coronary syndrome, previous coronary artery bypass graft, reduced left ventricular ejection fraction, B2C lesion and ISR lesion were independent predictors of 12 months TLF in the overall study population. Conclusions This large multicenter DCB registry study revealed the favorable clinical outcome of DCB treatment in real-world practice in patient with ISR lesion as well as small de novo coronary lesion.

Background and Objectives: This study aimed to investigate the association between cardiovascular events and 2 different levels of elevated on-treatment diastolic blood pressures (DBP) in the presence of achieved systolic blood pressure targets (SBP). Methods: A nation-wide population-based cohort study comprised 237,592 patients with hypertension treated. The primary endpoint was a composite of cardiovascular death, myocardial infarction, and stroke. Elevated DBP was defined according to the Seventh Report of Joint National Committee (JNC7; SBP <140 mmHg, DBP ≥90 mmHg) or to the 2017 American College of Cardiology/American Heart Association (ACC/AHA) definitions (SBP <130 mmHg, DBP ≥80 mmHg). Results: During a median follow-up of 9 years, elevated on-treatment DBP by the JNC7 definition was associated with an increased risk of the occurrence of primary endpoint compared with achieved both SBP and DBP (adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 1.05–1.24) but not in those by the 2017 ACC/AHA definition. Elevated ontreatment DBP by the JNC7 definition was associated with a higher risk of cardiovascular mortality (aHR, 1.42; 95% CI, 1.18–1.70) and stroke (aHR, 1.19; 95% CI, 1.08–1.30). Elevated on-treatment DBP by the 2017 ACC/AHA definition was only associated with stroke (aHR, 1.10;95% CI, 1.04–1.16). Similar results were seen in the propensity-score-matched cohort. Conclusion Elevated on-treatment DBP by the JNC7 definition was associated a high risk of major cardiovascular events, while elevated DBP by the 2017 ACC/AHA definition was only associated with a higher risk of stroke. The result of study can provide evidence of DBP targets in subjects who achieved SBP targets.

Objective: The purpose of this study was to compare the physical work intensity of emergency medicine (EM) and non-EM residents during a 24-hour work duty cycle using a smartwatch. Methods: This study was conducted for a month from 7 May to 4 June 2021. A total of 27 residents submitted their consent to be recruited as subjects for the study. We distributed a smartwatch to each of the participants and measured their physical work intensity. Twenty non-EM residents wore a smartwatch for a week. Also, seven EM residents wore a watch during the time they were on 24-hour duty for the whole research period. After finishing their 24-hour duty, participants took off the smartwatch and stopped recording their physical activities. Sixty-five samples were matched for comparison between the non-EM and EM residents. Each of the samples comprised a pair of 24-hour records of EM and non-EM residents. The data were matched to ensure the same date and grade and thus control the variables. Results: The results of this study showed that the maximum heart rate of the EM residents was 129.7±3.8 beats/min, which was higher than that of the non-EM residents. A comparison of the sleep hours during the 24-hour duty showed that the average sleep time of the EM residents was 156.9±84.8 minutes, which was significantly lower than that of the non-EM residents. However, calorie consumption, moving distance, and step count during the 24-hour duty cycle showed no significant difference between the EM and non-EM residents. Conclusion The maximum heart rate was higher among EM residents during their 24-hour work duty compared to the non-EM residents. In addition, the sleep time of the EM residents was significantly lower than that of the non-EM residents.

Background: There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI. Methods: Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed. Results: Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI;additionally, age (65–74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI. Conclusions Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.

Objective: Although several studies have been conducted on the use of ultrasound to assist in arterial punctures, its utility is controversial and it is also inconvenient to use the equipment in the emergency room. Therefore, we developed a radial artery puncture assistive device for use in the emergency room and evaluated its utility. Methods: The operator attempted the procedure on a mannequin, both with and without the device. We recorded the first-attempt success rate, the number of punctures, the time to success, and the failure rate. We conducted a survey to assess pre-experiment expectation and post-experiment satisfaction. Results: The first-attempt success rate was 78% with no device and 66% with the device (P=0.105). The failure rate was 5% both when the device was not worn and worn (P>0.99). The number of attempts was 2.18 with no device and 2.10 with the device (P=0.765). The time to success was 40.81 seconds without the device and 54.08 seconds with the device (P=0.307). The responses to the pre-experiment survey were 5% for ‘Not wearing the device seems to be more helpful’, 75% for ‘Wearing the device seems to be more helpful’, and 20% for ‘There seems to be no difference’. In the postexperiment survey, the responses were 30% for ‘Not wearing the device was more helpful’, 55% for ‘Wearing the device was more helpful’, and 15% for ‘There was no difference’. Conclusion There were no significant results from the experiments. But respondents felt that wearing the device was better in both the pre-experiment and post-experiment survey.

Background/Aims: Hypertension (HT) has a significant impact on public health and medical expenses. However, HT is a chronic disease that requires the long-term follow-up of a large number of patients. Methods: The Korean Hypertension Cohort (KHC) study aimed to develop a model for calculating cardiovascular risk in HT patients by linking and utilizing the detailed clinical and longitudinal data from hospitals and the national health insurance claim database, respectively. This cohort had a planned sample size of over 11,000 HT patients and 100,000 non-HT controls. Eligible patients were hypertensive patients, who were presenting for the first time and were diagnosed with HT as a main disease from 2006 to 2011. Long-term survival data over a period of approximately 9 years were obtained from the national health insurance claim and national health examination data. Results: This cohort enrolled 11,083 patients with HT. The mean age was 58.87 ± 11.5 years, 50.5% were male, and 31.4% were never-treated HT. Of the enrolled patients, 32.9% and 37.7% belonged to the high and moderate cardiovascular risk groups, respectively. Initial blood pressures were 149.4 ± 18.5/88.5 ± 12.5 mmHg. During the 2 years hospital data follow-up period, blood pressures lowered to 130.8 ± 14.1/78.0 ± 9.7 mmHg with 1.9 ± 1.0 tablet doses of antihypertensive medication. Cardiovascular events occurred in 7.5% of the overall patients; 8.5%, 8.8%, and 4.7% in the high, moderate, and low risk patients, respectively. Conclusions The KHC study has provided important information on the long-term outcomes of HT patients according to the blood pressure, comorbid diseases, medication, and adherence, as well as health behaviors and health resource use.