Comparison of Psychological and Cognitive Characteristics between Professional Internet Game Players and Professional Baseball Players.

The esports industry is increasing in popularity and is now played at the professional level. We hypothesized that esports players may have a significant advantage over the general population in terms of psychological and cognitive characteristics, which may be similar to that of professional baseball players. We recruited three participant groups: esports players (n = 55), pro-baseball players (n = 57), and age- and sex-matched healthy comparison subjects (n = 60). We assessed psychological status using the Korean versions of Temperament and Character Inventory and State and Trait Anxiety Inventory and cognitive functions using the modified Tower of London, Emotional Perception, and Mental Rotation tests. Esports players had similar psychological characteristics to pro-baseball players (higher novelty seeking [p < 0.01 *, ŋ = 0.818], self-directedness [p < 0.01 *, ŋ = 0.757], and self-transcendence scores [p < 0.01 *, ŋ = 0.853], and decreased state anxiety scores [p < 0.01 *, ŋ = 0.808]), which differed from those of the general population. However, esports players showed higher working memory [p < 0.01 *, ŋ = 0.823] and slower emotional perception than pro-baseball players [p < 0.01 *, ŋ = 0.812]. In conclusion, esports and pro-baseball players had similar psychological but different cognitive characteristics.

A Study on Heuristic Transportation Routes of Patients with Acute Dysbarism for the Best Prognosis

PURPOSE: Acute dysbarism is a potentially lethal injury associated with environmental medicine. Therefore, prompt treatment, including transportation of victims, is important for the best prognosis. The aim of this study was to examine transportation routes of patients with acute dysbarism for the best prognosis in Korea. METHODS: Geography of South Korea was analyzed using the geographic information system (GIS). The study examined two scenarios using transportation analysis, which relies on a GIS base and pressure variation during air and ground transportation. Given the practical assumptions, we propose some heuristic transportation routes based on the simulation of altitude, transportation time, and availability of related factors. RESULTS: Currently, transportation by ground to the treatment facilities always passes high altitude areas above 152 feet. Also, available helicopters for air transportation could not approach the treatment facilities due to the limitation of flying distance and insufficiency of medical staff and treatment equipment. Altitude variation and delayed time were identified during the period of transportation by ground from Ganneung or Incheon to Tongyoung. Heuristic algorism through the above facts recommends air transport along coasts as the best method for transportation from Ganneung or Incheon to Tongyoung. CONCLUSION: In Korea, transportation by ground was not expected to result in the best prognosis for patients with acute dysbarism. Transportation by air should be considered first as the method of transportation. Also, for the best treatment of patients with acute dysbarism, additional treatment facilities need to be established in the west coast region.

Basics of particle therapy II: relative biological effectiveness.

In the previous review, the physical aspect of heavy particles, with a focus on the carbon beam was introduced. Particle beam therapy has many potential advantages for cancer treatment without increasing severe side effects in normal tissue, these kinds of radiation have different biologic characteristics and have advantages over using conventional photon beam radiation during treatment. The relative biological effectiveness (RBE) is used for many biological, clinical endpoints among different radiation types and is the only convenient way to transfer the clinical experience in radiotherapy with photons to another type of radiation therapy. However, the RBE varies dependent on the energy of the beam, the fractionation, cell types, oxygenation status, and the biological endpoint studied. Thus this review describes the concerns about RBE related to particle beam to increase interests of the Korean radiation oncologists' society.

Protective effects of hominis placenta hydrolysates on radiation enteropathy in mice.

The aim of this study was to investigate whether the hominis placenta hydrolysates (HPhs) have a protective effect against radiation-induced enteropathies. HPh (1-10 mg kg⁻¹, i.p.) was treated to C57BL/6 mice, once daily for 5 days. Mice were irradiated (10 Gy) 1 h after the last injection. Cell damage was investigated at 24 and 72 h by haematoxylin-eosin staining, and the apoptotic index was determined at 24 h by deoxynucleotidyl transferase-mediated dUTP nick end labelling staining. The results showed that the HPh alleviated radiation-induced damage of crypts and suppressed apoptosis dose dependently. In conclusion, hominis placenta might be a beneficial agent against radiation-induced intestinal complications.

Basics of particle therapy I: physics.

With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfill the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest.

Co-authorship patterns and networks of Korean radiation oncologists.

PURPOSE: This research aimed to analyze the patterns of co-authorship network among the Korean radiation oncologists and to identify attributing factors for the formation of networks. MATERIALS AND METHODS: A total of 1,447 articles including contents of 'Radiation Oncology' and 'Therapeutic Radiology' were searched from the KoreaMed database. The co-authorship was assorted by the author's full name, affiliation and specialties. UCINET 6.0 was used to figure out the author's network centrality and the cluster analysis, and KeyPlayer 1.44 program was used to get a result of key player index. Sociogram was analyzed with the Netdraw 2.090. The statistical comparison was performed by a t-test and ANOVA using SPSS 16.0 with p-value < 0.05 as the significant value. RESULTS: The number of articles written by a radiation oncologist as the first author was 1,025 out of 1,447. The pattern of co-authorship was classified into five groups. For articles of which the first author was a radiation oncologist, the number of single-author articles (type-A) was 81; single-institution articles (type-B) was 687; and multiple-author articles (type-C) was 257. For the articles which radiation oncologists participated in as a co-author, the number of single-institution articles (type-D) was 280 while multiple-institution articles (type-E) were 142. There were 8,895 authors from 1,366 co-authored articles, thus the average number of authors per article was 6.51. It was 5.73 for type-B, 6.44 for type-C, 7.90 for type-D, and 7.67 for type-E (p = 0.000) in the average number of authors per article. The number of authors for articles from the hospitals published more than 100 articles was 7.23 while form others was 5.94 (p = 0.005). Its number was 5.94 and 7.16 for the articles published before and after 2001 (p = 0.000). The articles written by a radiation oncologist as the first author had 5.92 authors while others for 7.82 (p = 0.025). Its number was 5.57 and 7.71 for the Journal of the Korean Society for Therapeutic Radiology and Oncology and others (p = 0.000), respectively. Among the analysis, a significant difference in the average number of author per article was indicated. The out-degree centrality of network among authors was 4.26% (2.03.7.09%) while in-degree centrality was 1.31% (0.53.2.84%). The three significant nodes were classified and listed as following: Choi, Eun Kyung for 1991-1995, Kim, Dae Young for 1998-2001, Park, Won and Lee, Sang Wook for 2003-2010. Choi, Eun Kyung and Kim, Dae Young appeared in two cases, and ranked as the highest degree in centrality. In the key player analysis, Choi, Eun Kyung and Lee, Sang Wook appeared in two cases, and ranked as the highest. From the cluster analysis, Sungkyunkwan University, Seoul National University and Yonsei University revealed as the three large clusters when Ulsan University, Chonnam National University, and Korea Institute of Radiological & Medical Science as the medium clusters. CONCLUSION: The Korean radiation oncologist's society shows a closed network with numerous relationships among the particular clusters, and the result indicates it is different from other institutions in the pattern of co-authorship formation of the major hospitals.

A Study on Hyperbaric Chambers for Treating Decompression Sickness in the Republic of Korea

PURPOSE: With the recent increase in underwater activity, the number of people at risk for decompression sickness has greatly increased. However, an organized medical system for emergency treatment, evacuation, and hyperbaric oxygen therapy of decompression sickness has not been established yet. We collected information about domestic hyperbaric chambers available for treating decompression sickness. METHODS: We identified 95 hyperbaric chambers in hospitals, hydrospace construction corporations, military, maritime police, 119 rescue services, and other organizations through a telephone survey. We visited the 95 chambers and collected information about location, operating institutes, chamber specifications, and operational status. Twenty-four oxygen capsules were excluded from the study because of inadequate working pressure. RESULTS: Seventy-one hyperbaric chambers available for hyperbaric oxygen therapy were identified among 59 organizations. The hyperbaric chambers were distributed evenly along coastal lines; that is, 21 on the east coast, 26 on the west coast, 21 on the southern coast, and three on Jeju Island. Thirty-eight chambers with maximal working pressure of > or =5 atm could be used for severe decompression sickness and arterial gas embolism treatment. Twenty-nine chambers had a seating capacity equal to-or more than three patients. Twenty-eight chambers had two or more compartments; thus, they could handle complex medical situations. Thirty-eight chambers with medical locks were useful for severe decompression sickness treatment. CONCLUSION: A sufficient number of domestic hyperbaric chambers available for treating decompression sickness were distributed evenly along the coastal lines. However, potential barriers need to be overcome to establish an efficient decompression sickness treatment system.

A long term results of external beam radiation therapy in hemophilic arthropathy of the ankle in children.

Bleeding into joint space is critical to develop hemophilic arthropathy. To reduce the frequency of bleeding in the ankle joint of children with hemophilic arthropathy, low dose external beam irradiation was performed for 37 patients. Among them, 35 patients followed-up for longer than 1 yr (median 87 months) were enrolled for analysis. The average number of bleedings per month was 3.6 during one year prior to radiation therapy. After radiation therapy, it was decreased to 2.1 during the first year, after then it was maintained in the range of 1.0 to 1.5 until the tenth year. The bleeding frequency was reduced to 42% at the first year and it was maintained in the range of 58% to 73% from the second to the tenth year. Especially the patients who had 3 or more bleedings per month, and who had MRI score more than 3 showed significant decreases. During the follow-up period, growth disturbances and secondary malignancies were not found. External beam radiotherapy can be considered for the hemophilic patients with surgical or isotope therapies are not amenable.

Analysis of Scientific Publication Networks among Medical Schools in Korea.

OBJECTIVES: This research was intended to analyze the special characteristics and structure of social networks among Korean medical schools for the purpose of providing knowledge regarding medical field structure, dynamics, and potential paradigm development. METHODS: A collaborative 12-year data set of 35,469 published articles in the SCOPUS® database was analyzed. Among ISI subcategories, 61 having more than 20 articles were scrutinized. Following identification of correspondence and co-authorship, centralization indices and Key Player analysis were run for each subcategory. Medical schools were grouped into uniform clusters with convergence of iterated correlation (CONCOR) for structural equivalence. Finally, multidimensional scaling was used to visualize similarities. RESULTS: All centralization indexes analyzed demonstrated a shift in the degree of centralization in the network of medical schools throughout the period examined. Betweenness centrality and eigenvector centrality in particular revealed a dramatic change indicating minimization of the role of a specific "gatekeeper". Key Player analysis confirmed Seoul National University as a constant 'key player' throughout the period evaluated and for the subcategories examined as well. CONCLUSIONS: This study provided insight into the scientific network among the medical schools of Korea. By understanding this network, a strategy to strengthen the basis of research may be developed.

Adaptive responses induced by low dose radiation in dentate gyrus of rats.

The purpose of this study is to investigate the mechanism of alternative responses to low dose irradiation for neuronal cell proliferation in the dentate gyrus of rats. To determine the effect of a single exposure to radiation, rats were irradiated with a single dose of 0.1, 1, 10 or 20 Gy. To determine the effect of the cumulative dose, the animals were irradiated daily with 0.01 Gy or 0.1 Gy from 1 to 4 days. The neuronal cell proliferation was evaluated using immunohistochemistry for 5-bromo-2'-deoxyuridine (BrdU), Ki-67 and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining. Four consecutive daily irradiations with a 0.01 Gy/fraction increased the number of BrdU-positive and Ki-67-positive cells in a dose dependent manner, but this did not affect the number of TUNEL-positive cells. However, there was not a dose dependent relationship for the 0.1 Gy/fraction irradiation with the number of BrdU, Ki-67 and TUNEL positive cells. Our data support the explanation that the adaptive response, induced by low-dose radiation, in the hippocampus of rats is more likely a reflection of the perturbations of cell cycle progression.

Low dose radiation overcomes diabetes-induced suppression of hippocampal neuronal cell proliferation in rats.

We investigated the effect of low dose radiation on diabetes induced suppression of neurogenesis in the hippocampal dentate gyrus of rat. After 0.01 Gy, 0.1 Gy, 1 Gy and 10 Gy radiation was delivered, the dentate gyrus of hippocampus of streptozotocin (STZ)-induced diabetic rats were evaluated using immunohistochemistry for 5-bromo-2-deoxyuridine (BrdU), caspase-3, and terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) staining. The number of BrdU positive cells in the non-diabetic rats, diabetic rats without radiation, diabetic rats with 0.01 Gy radiation, diabetic rats with 0.1 Gy radiation, diabetic rats with 1 Gy radiation and diabetic rats with 10 Gy radiation were 55.4+/-8.5/mm2, 33.3+/-6.4/mm2, 67.7+/-10.5/mm2, 66.6+/-10.0/mm2, 23.5+/-6.3/mm2 and 14.3+/-7.2/mm2, respectively. The number of caspase-3 positive cells was 132.6+/-37.4/mm2, 378.6+/-99.1/mm2, 15.0+/-2.8/mm2, 57.1+/-16.9/mm2, 191.8+/-44.8/mm2 and 450.4+/-58.3/mm2, respectively. The number of TUNEL-positive cells was 24.5+/-2.0/mm2, 21.7+/-4.0/mm2, 20.4+/-2.0/mm2, 18.96+/-2.1/mm2, 58.3+/-7.9/mm2, and 106.0+/-9.8/mm2, respectively. These results suggest low doses of radiation paradoxically improved diabetes induced neuronal cell suppression in the hippocampal dentate gyrus of rat.

Number of radiation oncologists in Korea, adequate or surplus?

PURPOSE: The purpose of this research is to discern and address the issues related to the radiation oncology manpower supply and its distribution. MATERIALS AND METHODS: The statistical data of the Annual Report of the Korea Central Cancer Registry (KCCR) from 1997 to 2002 and the Annual Report of the Korean Society of Radiation Oncology (KOSTRO) from 1997 to 2004 were used to predict the status of the human resources in 2015. The estimated demand and supply were calculated with the Microsoft Excel program (Microsoft, Redmond, WA). RESULTS: The demand for radiation oncologists is estimated to be 161 in 2015 and about 4.9 radiation oncologists will be in demand annually. In contrast, an average of 15 new radiation oncologists will be supplied annually so that the accumulated surplus of radiation oncologists until 2015 is estimated to be 74.1. The main reason for the surplus comes from the discrepancy between the increased number of radiation therapy patients and the need for radiation oncologists. When there is an increase of 1,000 radiation therapy patients, the demand for radiation oncologists increases only by 2.4. This phenomenon is especially evident in the top 10 hospitals where the average number of radiation therapy patients per radiation oncologist is 341, which is 58% higher than the average number (215) of other 46 hospitals. CONCLUSION: To prevent a surplus and to maintain the quality of management, the number of radiation therapy patients per radiation oncologist should be limited. Furthermore, coordinate control of the number of residency positions should be seriously considered.

The application of the Six Sigma program for the quality management of the PACS.

OBJECTIVE: We implemented a Six Sigma-based quality management program for the PACS to improve the quality of and lessen the necessary resources for its management. CONCLUSION: With the Six Sigma-based PACS quality management program, we were able to reduce resource requirements while maintaining quality.

Comparison of hospital charge prediction models for colorectal cancer patients: neural network vs. decision tree models.

Analysis and prediction of the care charges related to colorectal cancer in Korea are important for the allocation of medical resources and the establishment of medical policies because the incidence and the hospital charges for colorectal cancer are rapidly increasing. But the previous studies based on statistical analysis to predict the hospital charges for patients did not show satisfactory results. Recently, data mining emerges as a new technique to extract knowledge from the huge and diverse medical data. Thus, we built models using data mining techniques to predict hospital charge for the patients. A total of 1,022 admission records with 154 variables of 492 patients were used to build prediction models who had been treated from 1999 to 2002 in the Kyung Hee University Hospital. We built an artificial neural network (ANN) model and a classification and regression tree (CART) model, and compared their prediction accuracy. Linear correlation coefficients were high in both models and the mean absolute errors were similar. But ANN models showed a better linear correlation than CART model (0.813 vs. 0.713 for the hospital charge paid by insurance and 0.746 vs. 0.720 for the hospital charge paid by patients). We suggest that ANN model has a better performance to predict charges of colorectal cancer patients.

The prognostic effect of VEGF expression in squamous cell carcinoma of the cervix treated with radiation therapy alone.

We investigated the relationship between vascular endothelial growth factor (VEGF) expression and clinical outcome in squamous cell carcinoma of the cervix treated with radiotherapy alone. The immunohistochemical study was performed for forty-two paraffin embedded specimens with anti-VEGF mouse monoclonal antibody. Staining was defined as positive for VEGF when more than 10% of the tumor cells were stained from 500 cells counted. Positive VEGF expression was observed in twenty-one among forty-two patients. VEGF expression according to stage (p=0.101), lymph node status (p=0.621), parametrial invasion (p=0.268), and age (p=0.5) revealed no significant difference. But the VEGF expression was significantly higher in tumors larger than 4 cm (p=0.031). Five year survival rates according to VEGF expression status were 89% for VEGF negative group and 47% for VEGF positive group (p=0.02). FIGO stage (p=0.007), tumor size (p=0.025) and the duration of external beam radiation therapy (p=0.006) were also significant prognostic factors for overall survival. We suggest that VEGF expression may be a prognotic factor of the cervix cancer patients treated with radiation therapy alone.

Clinical Implications of VEGF and p53 Expression in Squamous Cell Carcinoma of the Cervix Treated with Radiation Therapy.

PURPOSE: The present study was designed to analyze the relationship between vascular endothelial growth factor (VEGF) and p53, and their impact on clinical outcome in squamous cell carcinoma of the cervix treated with radiation therapy. MATERIALS AND METHODS: This immunohistochemical study involved 23 patients with available paraffin blocks among 46 patients who were treated during the period from 1994 to 1997 in Eulji University Hospital in Korea. Anti-VEGF mouse monoclonal antibody and DO-7 anti- p53 mouse monoclonal antibody were used as the primary antibodies. Antibody binding was detected with a LSAB kit. Staining was defined as positive for VEGF and p53, when more than 10% and 5% of the tumor cells were stained out of 500 cells counted, respectively. RESULTS: FIGO stage (p=0.05) and tumor size (p=0.04) were significant prognostic factors for survival. p53 expression was present in 17 (77%) cases. There was no significant relationship between p53 staining and the clinicopathologic factors, such as FIGO stage (p=0.98), tumor size (p=0.43), lymph node status (p=0.82), parametrial invasion (p=0.96), and age (p=0.18). The five year survival rates according to the p53 expression status were 80% for the p53 negative group and 66% for the p53 positive group (p=0.58). Positive VEGF expression was observed in 11 (47%) of the total of 23 patients. Statistical evaluation of VEGF expression according to stage (p=0.36), tumor size(p=0.11), lymph node status (p=0.82), parametrial invasion (p=0.49), and age (p=0.55) revealed no significant difference in any of these parameters. The five year survival rates according to the VEGF expression status were 89% for the VEGF negative group and 41% for the VEGF positive group (p=0.07). CONCLUSION: We suggest that VEGF expression may have an effect on the prognosis of cervix cancer patients treated with radiation therapy, and further evaluation with a large sample size is warranted.