Erratum: Correction of Text in the Article "Evidence of Long-Distance Droplet Transmission of SARS-CoV-2 by Direct Air Flow in a Restaurant in Korea".

This corrects the article on p. e415 in vol. 35, PMID: 33258335.

Evidence of Long-Distance Droplet Transmission of SARS-CoV-2 by Direct Air Flow in a Restaurant in Korea.

BACKGROUND: The transmission mode of severe acute respiratory syndrome coronavirus 2 is primarily known as droplet transmission. However, a recent argument has emerged about the possibility of airborne transmission. On June 17, there was a coronavirus disease 2019 (COVID-19) outbreak in Korea associated with long distance droplet transmission. METHODS: The epidemiological investigation was implemented based on personal interviews and data collection on closed-circuit television images, and cell phone location data. The epidemic investigation support system developed by the Korea Disease Control and Prevention Agency was used for contact tracing. At the restaurant considered the site of exposure, air flow direction and velocity, distances between cases, and movement of visitors were investigated. RESULTS: A total of 3 cases were identified in this outbreak, and maximum air flow velocity of 1.2 m/s was measured between the infector and infectee in a restaurant equipped with ceiling-type air conditioners. The index case was infected at a 6.5 m away from the infector and 5 minutes exposure without any direct or indirect contact. CONCLUSION: Droplet transmission can occur at a distance greater than 2 m if there is direct air flow from an infected person. Therefore, updated guidelines involving prevention, contact tracing, and quarantine for COVID-19 are required for control of this highly contagious disease.

A Novel PBPK Modeling Approach to Assess Cytochrome P450 Mediated Drug-Drug Interaction Potential of the Cytotoxic Prodrug Evofosfamide.

Evofosfamide is a cytotoxic small-molecule prodrug preferentially activated under hypoxic conditions. The cytotoxicity of evofosfamide impacted the generation of in vitro drug-drug interaction (DDI) data, especially in vitro induction results. Therefore, a novel physiologically based pharmacokinetic (PBPK) approach was used, which involved available in vitro and clinical data of evofosfamide and combined it with induction data from the prototypical cytochrome P450 (CYP)3A inducer rifampicin. The area under the concentration-time curve (AUC) ratios of midazolam were above 0.80, indicating that induction of CYP3A by evofosfamide administered weekly is unlikely to occur in humans. Moreover, static and PBPK modeling showed no clinically relevant inhibition via CYP2B6, CYP2D6, and CYP3A4. In conclusion, PBPK models were used to supplement in vitro information of a cytotoxic compound. This approach may set a precedent for future studies of cytotoxic drugs, potentially reducing the need for clinical DDI studies and providing more confidence in the clinical use of approved cytotoxic compounds for which DDI information is sparse.

Comparison of hypoxia-activated prodrug evofosfamide (TH-302) and ifosfamide in preclinical non-small cell lung cancer models.

Evofosfamide (TH-302) is a hypoxia-activated prodrug of the cytotoxin bromo-isophosphoramide. In hypoxic conditions Br-IPM is released and alkylates DNA. Ifosfamide is a chloro-isophosphoramide prodrug activated by hepatic Cytochrome P450 enzymes. Both compounds are used for the treatment of cancer. Ifosfamide has been approved by the FDA while evofosfamide is currently in the late stage of clinical development. The purpose of this study is to compare efficacy and safety profile of evofosfamide and ifosfamide in preclinical non-small cell lung cancer H460 xenograft models. Immunocompetent CD-1 mice and H460 tumor-bearing immunocompromised nude mice were used to investigate the safety profile. The efficacy of evofosfamide or ifosfamide, alone, and in combination with docetaxel or sunitinib was compared in ectopic and intrapleural othortopic H460 xenograft models in animals exposed to ambient air or different oxygen concentration breathing conditions. At an equal body weight loss level, evofosfamide showed greater or comparable efficacy in both ectopic and orthotopic H460 xenograft models. Evofosfamide, but not ifosfamide, exhibited controlled oxygen concentration breathing condition-dependent antitumor activity. However, at an equal body weight loss level, ifosfamide yielded severe hematologic toxicity when compared to evofosfamide, both in monotherapy and in combination with docetaxel. At an equal hematoxicity level, evofosfamide showed superior antitumor activity. These results indicate that evofosfamide shows superior or comparable efficacy and a favorable safety profile when compared to ifosfamide in preclinical human lung carcinoma models. This finding is consistent with multiple clinical trials of evofosfamide as a single agent, or in combination therapy, which demonstrated both anti-tumor activity and safety profile without severe myelosuppression.

Effects of carnitine on peripheral blood mitochondrial DNA copy number and liver function in non-alcoholic fatty liver disease.

BACKGROUND/AIMS: Functional and anatomical abnormalities of mitochondria play an important role in developing steatohepatitis. Carnitine is essential for enhanced mitochondrial beta oxidation through the transfer of long-chain fatty acids into the mitochondria. We examined the impact of carnitine complex on liver function and peripheral blood mitochondria copy number in NAFLD patients. METHODS: Forty-five NAFLD patients were enrolled. Patients were categorized into the carnitine complex-administered group and control group. Before and 3 months after drug administration, a liver function test and peripheral blood mitochondrial DNA and 8-oxo-dG quantitive analysis were conducted. RESULTS: In carnitine treatment group, ALT, AST, and total bilirubin were reduced after medication. There was no difference in AST, ALT, and total bilirubin between before and after treatment in control group. In carnitine group, peripheral mitochondrial DNA copy number was significantly increased from 158.8+/-69.5 copy to 241.6+/-180.6 copy (p=0.025). While in control group the mitochondrial copy number was slightly reduced from 205.5+/-142.3 to 150.0+/-109.7. 8-oxo-dG level was also tended to decrease in carnitine group (p=0.23) and tended to increase in control group (p=0.07). CONCLUSIONS: In NAFLD, the carnitine improved liver profile and peripheral blood mitochondrial DNA copy number. This results suggest that carnitine activate the mitochondria, thereby contributing to the improvement of NAFLD.

Effects of Carnitine on Peripheral Blood Mitochondrial DNA Copy Number and Liver Function in Non-Alcoholic Fatty Liver Disease / 대한소화기학회지

BACKGROUND/AIMS: Functional and anatomical abnormalities of mitochondria play an important role in developing steatohepatitis. Carnitine is essential for enhanced mitochondrial beta oxidation through the transfer of long-chain fatty acids into the mitochondria. We examined the impact of carnitine complex on liver function and peripheral blood mitochondria copy number in NAFLD patients. METHODS: Forty-five NAFLD patients were enrolled. Patients were categorized into the carnitine complex-administered group and control group. Before and 3 months after drug administration, a liver function test and peripheral blood mitochondrial DNA and 8-oxo-dG quantitive analysis were conducted. RESULTS: In carnitine treatment group, ALT, AST, and total bilirubin were reduced after medication. There was no difference in AST, ALT, and total bilirubin between before and after treatment in control group. In carnitine group, peripheral mitochondrial DNA copy number was significantly increased from 158.8+/-69.5 copy to 241.6+/-180.6 copy (p=0.025). While in control group the mitochondrial copy number was slightly reduced from 205.5+/-142.3 to 150.0+/-109.7. 8-oxo-dG level was also tended to decrease in carnitine group (p=0.23) and tended to increase in control group (p=0.07). CONCLUSIONS: In NAFLD, the carnitine improved liver profile and peripheral blood mitochondrial DNA copy number. This results suggest that carnitine activate the mitochondria, thereby contributing to the improvement of NAFLD.

Potent and highly selective hypoxia-activated achiral phosphoramidate mustards as anticancer drugs.

A series of achiral hypoxia-activated prodrugs were synthesized on the basis of the DNA cross-linking toxin of the prodrug, ifosfamide. The hypoxia-selective cytotoxicity of several of the compounds was improved over previously reported racemic mixtures of chiral bioreductive phosphoramidate prodrugs. Prodrugs activated by 2-nitroimidazole reduction demonstrated up to 400-fold enhanced cytotoxicity toward H460 cells in culture under hypoxia versus their potency under aerobic conditions. Compounds were further assessed for their stability to cytochrome P450 metabolism using a liver microsome assay. The 2-nitroimidazole containing lead compound 3b (TH-302) was selectively potent under hypoxia and stable to liver microsomes. It was active in an in vivo MIA PaCa-2 pancreatic cancer orthotopic xenograft model as a monotherapy and demonstrated dramatic efficacy when used in combination with gemcitabine, extending survival with one of eight animals tumor free at day-44. Compound 3b has emerged as a promising antitumor agent that shows excellent in vivo efficacy and is currently being evaluated in the clinic.

A Case of Cutaneous Protothecosis / 대한의진균학회지

Cutaneous protothecosis is a rare skin infection, caused by the genus prototheca, especially Prototheca wickerhamii. A 73-year-old woman had a painful, ulcerative patch and oozing plaque on left wrist and dorsum of hand for 2 months. Biopsy specimen revealed thick walled morula-like sporangia in the dermis. P. wickerhamii was isolated in the culture. Oral itraconazole therapy for 8 weeks is not satisfactory. New skin lesion is formed. After oral fluconazole therapy, patient's skin lesion is improved.

A 5Fr catheter approach reduces patient discomfort during transradial coronary intervention compared with a 6Fr approach: a prospective randomized study.

Smaller guiding catheters can help reduce local complications and patient morbidity during transradial coronary intervention (TRI). This study was designed to compare the patient's morbidity, success rate, and the operator's convenience between 5-French (5Fr) and 6-French (6Fr) TRIs. This is a single-center prospective randomized study. Patients who underwent TRI, in 2003, were prospectively randomized to either 5Fr or 6Fr catheter groups (100 patients in each group). Procedure-related patient morbidity as well as clinical and procedural characteristics was scored and analyzed. Procedural success rate was not significantly different between the groups. The number of unsatisfactory supports (6% in 5Fr group, 3% in 6Fr group; P=0.31) and the incidence of local wound complications were not significantly different between the groups. Local wound pain scores were significantly lower in the 5Fr group compared with the 6Fr group, particularly during sheath insertion and removal, and during procedures. Pain scores were higher in female patients than in male patients during sheath removal (male: 1.3+/-1.3, female: 1.7+/-1.5; P=0.049). Radial artery diameter was well correlated with local pain score during sheath removal (r=0.31, P<0.001), and with the height and weight of the patients (height: r=0.33, P<0.001; weight: r=0.27, P<0.001). In conclusion, using a 5Fr catheter during TRI reduce, local access site pain, particularly in female patients with smaller body size, whereas the success and local complication rates were similar to a 6Fr approach.

Enhancement of Gene Delivery into Mouse Skeletal Muscle with Microbubble Destruction by Low-Frequency Ultrasound

BACKGROUND AND OBJECTIVES: The aim of this study was to investigate the value of microbubble destruction using low-frequency ultrasound for enhancing gene delivery to skeletal muscles of laboratory animals. MATERIALS AND METHODS: Lac-Z gene was injected into 21 mouse anterior tibialis muscles. Seven muscles received the gene only, and seven each received either 20-kHz ultrasound exposure or ultrasound-PESDA (perfluorocarbon-exposed sonicated albumin) destruction, respectively, following the injection; the extent of Lac-Z expression was then compared. Luciferase gene was injected into the muscles (N=80). The muscles were divided into two groups according to the mixture; in the first group saline was used as the mixture solute, with PESDA used in the second group. The groups were subdivided into two groups, one receiv 10 seconds of ultrasound at the injection site after injection, and the other that received no further intervention. Luciferase activities were measured and compared. RESULTS: The proportions of Lac-Z stained cells were 0, 5.7+/-1.2 and 7.7+/-1.7%, respectively, showing a significant stepwise increase microbubble destruction (p<0.05). Luciferase activities were as follows: Luciferase only (Group 1, N=17), 5727+/-2178 RLU/mg; luciferase plus PESDA (Group 2, N=17), 1170+/-470.7 RLU/mg; luciferase plus ultrasound (Group 3, N=17), 16480+/-5239 RLU/mg; and luciferase plus PESDA destruction (Group 4, N=17), 49910+/-16500 RLU/mg. The activity in group 4 was significantly higher than in group 1 (p<0.01), showing an 8.7-fold increase in gene delivery due to microbubble destruction. CONCLUSION: Microbubble destruction using low-frequency ultrasound is an efficient method for increasing the efficacy of direct gene delivery to skeletal muscles.

Feasibility and safety of the transradial approach for the intracoronary spasm provocation test.

An angiography-based spasm provocation test is an accurate diagnostic test of coronary vasospastic angina, but is associated with high patient morbidity, mainly because of the femoral approach and the need for a temporary pacemaker. The purpose of this study was to investigate the safety and feasibility of a transradial ergonovine spasm provocation test. The test was performed prospectively in 174 consecutive patients who were under suspicion of coronary vasospasm at our institution from April 2002 to June 2003. Seventy-eight out of 174 procedures (45%) were performed in an outpatient department. The procedural success rate was 168/174 (96%). All failures were because of access failures, and no major complications were noted. Minor complications were observed in nine patients (severe bradycardia in three, hypotension in two, both in two, and nonsustained ventricular tachycardia in two). The incidence of complications was higher in patients showing prolonged spasm in the right coronary artery. No major local complication was noted other than rebleeding in the puncture site during hemostasis in one patient. The transradial spasm provocation test performed without using a temporary pacemaker may be feasible and safe, with a high success rate and low complication rate as well as low patient morbidity.

Study of Compliance to Antihypertensive Medication in Korean Hypertensive Patients Using Medication Event Monitoring System

BACKGROUND AND OBJECTIVES: Compliance to a prescribed antihypertensive regimen influences the management of hypertension in various steps, but studies on this issue are very rare in Korea. The medication event monitoring system (MEMS) is the gold standard in measurement of compliance, which is a special pill container, designed to electronically monitor drug intake patterns. Here, the authors investigated the compliance to the antihypertensive regimen in the cardiology practice of a tertiary care hospital using the MEMS. SUBJECTS AND METHODS: Monitoring using the MEMS was performed in 80 hypertensive patients during monotherapy. Demographic, clinical and psychological profiles were collected through a standardized questionnaire. The parameters used for compliance were the percentage of doses taken (PDT) and the percentage of doses taken correctly (PDTc), according to the prescribed regimen. RESULTS: The mean age of the patients and duration of monitoring were 53+/-10 years and 60+/-26 days, respectively. The median and range for the PDT and PDTc were 97% (88-100%) and 92% (80-97%), respectively. About 16% of patients showed relatively poor compliance (PDT<80%). Predicting factors for poor compliance were a recent history of self-discontinuation of drug treatment, not currently being on medication and a young age (p<0.05). Agreement between intuitive prediction by the physician and the actual compliance was closer to what would be expected by chance (kappa coefficient=-0.11). CONCLUSION: Although average compliance to the single drug antihypertensive regimen was relatively high in the cardiology practice of the tertiary care hospital in this study, a significant proportion of patients show low compliance. Special consideration should be given to patients with factors predictive of poor compliance. Investigation of compliances in other clinical settings is also warranted.

Characteristics and prevalence of intrapulmonary shunt detected by contrast echocardiography with harmonic imaging in liver transplant candidates.

We investigated the prevalence and characteristics of intrapulmonary shunt using contrast echocardiography with harmonic imaging in 130 liver transplant candidates. We found a high prevalence of intrapulmonary shunts and a significant correlation between the degree of intrapulmonary shunt and the Child-Pugh classification score.

Identification of proximal left anterior descending artery stenosis with thallium-201 defect patterns in patients with angina pectoris.

We determined the accuracy of perfusion defect patterns in predicting the presence of proximal left anterior descending (LAD) artery stenosis in patients with angina pectoris. The development population consisted of 80 patients with single-vessel LAD stenosis and reversible LAD territory defects on thallium-201 tomography. The types of defect patterns associated with angiographic proximal LAD stenosis in this population were categorized as "proximal LAD patterns." The accuracy of these patterns for identifying proximal LAD stenosis was evaluated in a separate validation population of 152 patients with angina pectoris. The development population demonstrated LAD territory defects of type I (most of the LAD territory; n = 12); type II (apex, apicoanterior, and most of the septum; n = 26), type III (septum; n = 19); type IV (anteroseptum; n = 6); type V (apex; n = 10); and type VI patterns (anterolateral wall; n = 7). Patients with type I, II, and IV patterns were highly associated with proximal LAD stenosis (38 of 44 segments), whereas those with type III, V, and VI patterns were mostly related to distal LAD disease (29 of 36 segments). In the validation population, proximal LAD patterns had a sensitivity, specificity, and accuracy of 72%, 95%, and 91%, respectively, for identifying patients with proximal LAD stenosis. Test sensitivity was 86% when patients without LAD territory defects were excluded from analysis. Results were virtually identical in the subgroup of 84 patients with stable angina. Thus, recognition of LAD territory thallium defect patterns is useful for identifying patients with angina who are likely to have proximal LAD stenosis.

The efficacy and safety of angioseal(R) compared to conventional manual compression after transfemoral percutaneous coronary intervention / 대한내과학회지

BACKGROUND: Although the number and the quality of percutaneous coronary intervention have been recently increased dramatically, the vascular complication at puncture site is still the major cause of patients' morbidity. We evaluated the safety and efficacy of newly-developed collagen-based arterial closure device, angioseal(R) after transfemoral percuatenous coronary intervention. METHODS: This study was designed as a prospective single center non-randomized comparative study. A total 200 patients undergoing transfemoral percutaneous coronary intervention were enrolled between April 2002 and May 2003. They were divided into two groups; angioseal(R) group (group A, n=100) and manual compression group (group B, n=100). The baseline clinical and angiographic characteristics were reviewed. The time to sit up, the time to ambulation, the duration of hospital stay, major and minor vascular puncture site complications were monitored. The patients were followed-up for 1 week after the procedure by telephone. RESULTS: The baseline clinical characteristics, clinical diagnosis, cardiovascular risk factors, types of procedure, doses and numbers of anticoagulants were similar between two groups. The blood pressure and activated clotting time were also similar. The time to sit up (group A: 4.3 0.3 hours, group B: 13.7 0.8 hours, p=0.004) and the time to ambulation (group A: 6.8 0.5 hours, group B: 18.8 2.1 hours, p=0.013) were shorter in group A. No major vascular complications were noted. The incidence of hematoma and bleeding were not significantly different between two groups. The incidence of ecchymosis, however, was significantly lower in group A (group A: 12%, group B: 3%, p=0.001) The duration of hospital stay was similar between two groups. During 7 days of follow-up period, the incidence of hematoma was significantly lower in group A (p=0.004). Although the incidence of ecchymosis was not significantly different between two groups. CONCLUSION: The angioseal(R) may be associated with earlier ambulation and less patients' morbidity with low incidence of local complication rate compared to manual compression after transfemoral percutaneous coronary intervention.

Correlation between Vascular Compliance and Increase of Blood Pressure on Exercising in Normotensive Group

BACKGROUND AND OBJECTIVES: Vascular compliance is known to be decreased in hypertension, even at an early stage. The blood pressure response to exercise reflects the future risk of developing hypertension. A study was performed on the relationship between the vascular compliance and blood pressure response to exercise, to evaluate whether the vascular compliance is decreased in normotensive persons with a relatively higher future risk of developing hypertension. SUBJECTS AND METHODS: The subjects of the study were adults with normal blood pressure (SBP<120 mmHg, DBP<80 mmHg), who had undergone health screening and both echocardiography and treadmill test. Those patients with a history of diabetes mellitus or clinical cardiovascular diseases were excluded form the subjects. An index of overall vascular compliance (SVI/PP) was calculated using echocardiography. The relationship between the peak systolic blood pressure during exercise and vascular compliance was also investigated. RESULTS: The subjects were 77 patients, 54 male and 23 female, with a mean age of 47.6+/-7.7 years. The measured vascular compliance and average of peak systolic pressure on exercising were 1.08+/-0.24 L/m2/mmHg and 154+/-21 mmHg, respectively. The peak systolic pressure was correlated with the vascular compliance (r=-0.24, p<0.05). The peak systolic pressure at stage 3 was also correlated with the vascular compliance (r=-0.24, p<0.05). This relationship persisted after adjustment for age, gender, basal systolic blood pressure and maximal oxygen consumption (p<0.05). CONCLUSION: The vascular compliance was lower in subjects with a larger increase in blood pressure during exercise whose basal blood pressure was even below 120/80 mmHg. This finding may suggest that a decreased vascular compliance precedes the changes of hypertension. A longitudinal follow-up study is warranted.

Safety of One-Day Admission Transradial Coronary Intervention

BACKGROUND: Recent advances of percutaneous coronary intervention (PCI) and transradial coronary intervention (TRI) have made it possible to reduce the local complication rate and the time until a return to ambulation. The aim of this study is to assess the safety and the patient satisfaction of the TRI-based one-day admission program for PCI. METHODS: Total 230 consecutive patients underwent TRI on the day of admission, according to pre-determined inclusion criteria, from May 2001 to October 2003. The subjects were examined for clinical and angiographic characteristics. The patients having a same-day discharge were telephone-interviewed one day and seven days after discharge to assess late complications and the patients' satisfaction. RESULTS: The mean age of the subjects was 59+/-9 years and 77.4% were male patients. 169 (73.4%) had stable angina and 37 (16.1%) had unstable angina. Stents were implanted in 178 cases (69.3%). Of the 230 patients who underwent TRI, 206 patients (89.6%) could discharge on the same day after the procedure. The procedure was successful in 98.5%. The average hospital stay for them was 9.4+/-1.4 hours. Two subjects reported hematoma near the puncture site within 24 hours after discharge, and one reported this problem 7 days after discharge. During the follow-up, there were no cases reporting chest pain needing rehospitalization or such complications as subacute vessel closure. No deaths, myocardial infarctions or revascularization were noted during the follow-up period. The majority of the patients (n=197, 95.6%) were satisfied with the same-day admission and discharge. CONCLUSIONS: Same day admission and discharge after TRI seems to be safe as well as satisfactory for not low-risk patients.

Effects of Chronic Alcohol Consumption on Midazolam Induced Sedation during Colonoscopy / 대한소화기내시경학회지

BACKGROUND/AIMS: It is suggested that patients consuming large amounts of alcohol are difficult to be sedated by midazolam probably due to cross tolerance. We studied to know the adequate administration doses of midazolam in patients with chronic alcohol consumption. METHODS: Study I; We prospectively studied 117 outpatients presenting for colonoscopy. According to alcohol consumption we divided four groups such as group I: 0 g/day, group II: 40 g/day. We initially administered 0.06 mg/kg midazolam and add up to spontaneous eye closure. We measured grade of amnesia, level of consciousness, endoscopist's assessment and VAS scale for pain after recovery. Study II; We measured induction time after 0.08 mg/kg midazolam in 60 patients who drink alcohol. RESULTS: Additional amount of midazolam was not significantly different between the groups (group I: 0.0145 mg/ kg, group II: 0.0214 mg/kg, group III: 0.0181 mg/kg, group IV: 0.0199 mg/kg). There were no differences of sedation parameters between the groups. However the induction time was prolonged and correlated with alcohol consumption. CONCLUSIONS: For adequate sedation in patients with chronic alcohol consumption, longer induction time rather than increasing dosage is required.

Predictors of Sinus Rhythm Restoration after Maze Operation and Relationship between Pre- and Post-operative Left Atrial Volume

BACKGROUND AND OBJECTIVES: The Maze operation is known to be an effective measure for restoring sinus rhythm in patients with atrial fibrillation (AF). The purpose of this study was to identify the relationship of pre- and post-operative left atrial volume (LAV) and diameter (LAD) with successful restoration of sinus rhythm in the Maze operation. SUBJECTS AND METHODS: The subjects for this study were 28 patients who underwent open-heart surgery in conjunction with the Maze-III operation for chronic AF from October, 2002, to April, 2003. Electrocardiographic and transthoracic echocardiographic studies were done pre-operatively and three months post-operatively. LAV and LAD were assessed and corrected for body surface area (LAV index=LAV/BSA, LAD index=LAD/BSA). RESULTS: Sinus rhythm was restored and maintained in 22 of the 28 patients (78.6%). Between the group with successful restoration of sinus rhythm (Group A;n=22) and the group with unsuccessful restoration (Group B;n=6), there was no difference in age, gender, and NYHA functional class. The duration of AF in group A was significantly shorter than that of B (3.6+/-2.7 years versus 15.8+/-7.5 years, p=0.003). Group A and B did not show any difference in pre-operative left ventricular ejection fraction. However, pre-operative LAV index in group A was significantly smaller than that of group B (80.7+/-22.4 mL/m2 versus 118.1+/-42.5 mL/m2, p=0.048). In group A, the LAV index (80.7+/-22.4 mL/m2 versus 52.8+/-14.7 mL/m2, p<0.001) and LAD index (35.4+/-5.3 mm/m2 versus 31.7+/-4.7 mm/m2, p=0.001) decreased significantly three months after the operation. In group B, however, no significant changes are found in the LAV index (118.1+/-42.5 mL/m2 versus 89.2+/-38.9 mL/m2, p=0.116) and LAD index (39.1+/-7.9 mm/m2 versus 36.2+/-9.2 mm/m2, p=0.144). CONCLUSION: Pre-operative LAV index measured by echocardiography and the duration of AF were significant predictors of successful sinus rhythm restoration after the Maze operation. Significant reduction of the LAV index after the Maze operation was found in patients whose rhythm was successfully restored and maintained.

A Qualitative Evaluation of Problem-Based Learning Curriculum by Students' Perceptions / 한국의학교육

PURPOSE: Recently established in 1997, Sungkyunkwan University School of Medicine was the first medical school in Korea to adopt problem-based learning (PBL) as a core curriculum from the very beginning. The purpose of this study was to evaluate the PBL curriculum from the viewpoint of the medical students. METHODS: This study used a qualitative approach to understand students' perceptions of the positive aspects of PBL. A total of 22 second-year medical students at Sungkynkwan medical school were surveyed. Student perceptions were obtained from questionnaires and face-to-face interviews. The interview was designed to evoke more personal and in-depth responses. RESULTS: Students' perceptions of the effects of PBL were found to be very favorable. Most students showed positive responses on the issues of more active learning attitude, self-directed learning, motivation to study, improved problem solving, and integrated learning. CONCLUSION: The results of this study demonstrated that the students had a good understanding of PBL and experienced its positive aspects of PBL approach. It might be concluded that PBL was successfully implemented into the curriculum and specific and expected effects of PBL accomplished.