BACKGROUND: The self-inflating bag-valve resuscitator is an useful breathing support equipment in the cardiopulmonary resuscitation, the transportation of patients who required ventilation assist, or respiratory therapy. The inspiratory oxygen concentration (FiO2) or tidal volume (VT) delivered to the patient depends on various conditions during bag-valve ventilation. METHODS: During bag-valve ventilation without a reservoir at oxygen flow rates of 10 l/min, we evaluated fifty six volunteers to determine the FiO2 and VT at ventilatory frequencies of 10, 12 and 15 cycles per minute and to observe the effect of hand size and grasp power on FiO2 and VT in two-hand compression methods. RESULT: The FiO2 at frequency of 10 cycles/min were 50.1% and it was higher than other ventilatory frequencies. However, the VT was not statistically different among the changes of ventilatory frequency. In the change of VT according to characteristics of the hand, the operator's hand size exerted influence on VT(larger vs. smaller ; 942ml vs. 885ml, p<0.05), but the grasp power of the hand did not significantly affect. Separate analyses with size or grasp power of the hand failed to reveal significant differences of the FiO2. CONCLUSION: The results suggest that a slowing of ventilatory frequency within the allowable ranges for adequate gas exchange increase the FiO2 during bag-valve ventilation without reservoir, and that hand size may exert influence on the VT without FiO2 changes but grasp power may not be a contributing factor to the VT or FiO2 changes.
Cardiopulmonary Resuscitation ; Hand Strength ; Hand* ; Humans ; Oxygen* ; Respiration ; Respiratory Therapy ; Tidal Volume* ; Transportation of Patients ; Ventilation* ; Volunteers

No abstract available.

Background: To suggest measures to prevent burnout of physicians during the coronavirus disease 2019 (COVID-19) pandemic, we conducted a systematic review of research on physician burnout due to COVID-19. Methods: Three foreign databases were used: MEDLINE, Embase, and the Cochrane Library. A search was performed using the following search terms: COVID-19, coronavirus, NCOV, physicians, doctors, residents, and burnout. Four rounds of review were performed to enhance the consistency of quality assessment. The Joanna Briggs Institute checklist for analytical cross-sectional studies was used to assess the quality of the eligible studies. Results: A total of 465 studies were identified, of which 32 were selected. The quality assessment determined that 19 studies met the Joanna Briggs Institute criteria and had a low risk of bias. The most common tool used to measure physician burnout in the 32 studies was the Maslach Burnout Inventory. Conclusion This study systematically evaluated the literature on physician burnout. However, the generalizability of our findings to Korean physicians may be limited. The composition of the medical personnel in Korea, such as open doctors, volunteer doctors, medical professors, and public health doctors, differs significantly from that of other countries. Nevertheless, evaluating the current status of physician burnout due to COVID-19 globally may hold meaningful implications for policymaking.

Background: To suggest measures to prevent burnout of physicians during the coronavirus disease 2019 (COVID-19) pandemic, we conducted a systematic review of research on physician burnout due to COVID-19. Methods: Three foreign databases were used: MEDLINE, Embase, and the Cochrane Library. A search was performed using the following search terms: COVID-19, coronavirus, NCOV, physicians, doctors, residents, and burnout. Four rounds of review were performed to enhance the consistency of quality assessment. The Joanna Briggs Institute checklist for analytical cross-sectional studies was used to assess the quality of the eligible studies. Results: A total of 465 studies were identified, of which 32 were selected. The quality assessment determined that 19 studies met the Joanna Briggs Institute criteria and had a low risk of bias. The most common tool used to measure physician burnout in the 32 studies was the Maslach Burnout Inventory. Conclusion This study systematically evaluated the literature on physician burnout. However, the generalizability of our findings to Korean physicians may be limited. The composition of the medical personnel in Korea, such as open doctors, volunteer doctors, medical professors, and public health doctors, differs significantly from that of other countries. Nevertheless, evaluating the current status of physician burnout due to COVID-19 globally may hold meaningful implications for policymaking.

Background: Many countries need help with the problem of an unbalanced distribution of physicians and hospitals. Moreover, various policies and strategies have been proposed to solve this problem. This study aimed to examine the determinants of the unbalanced distribution of physicians. Methods: From the 2020 Korean Physician Survey data, 4,181 physicians practicing in Korea were limited to the subjects of the study. We analyzed the factors influencing physicians’ choice of practice location and their willingness to change their practice location from an urban to a rural area. Results: The region of physicians’ hometown, medical school, and residency training hospitals determined their choice of practice location. The type of affiliated healthcare organization and the location of physicians’ hometown, medical school, and residency training hospitals affected their willingness to change their practice location from an urban to a rural area. Furthermore, the concordance rate of the regions of physicians’ hometown, medical school, and residency training hospitals with the region of their practice location was 24.9%. Conclusion In South Korea, policies for doctors have been designed without considering why they are reluctant to work in rural hospitals. To have a balanced distribution of physicians and hospitals, it is necessary to accurately analyze the status of medical resources based on regions and identify the current and future medical demand. The social situation, such as future demographic change and regional extinction, must also be fully considered. Furthermore, policies should be implemented that encourage physicians to work in rural hospitals.

PURPOSE: To investigate the in vitro effects of Dehydroepiandrosterone (DHEA)-pyruvate on human osteoarthritic chondrocytes. METHODS: Chondrocytes isolated from human osteoarthritic knee cartilage were three-dimensionally cultured in Alginate beads. Cells were treated with dehydroepiandrosterone in the presence or absence of IL-1. The effects on chondrocytes were analyzed by MTS assay (for chondrocytes proliferation), DMB assay (for glycosaminoglycan synthesis), and indole assay (for DNA amount). Gene expressions of MMP-1,3, TIMP-1 as well as IL-1 induced gene expression of MMP-1, 3 were analyzed using RT-PCR. The protein synthesis of MMP-1,3 and TIMP-1 was determined by ELISA. RESULTS: Treatment of chondrocytes with DHEA-pyruvate did not affect chondrocytes proliferation regardless of concentrations when compared with control. GAG synthesis was not changed significantly during culture period regardless of concentrations. DHEA-pyruvate suppressed the expression of MMP-1 significantly at a concentration of 50 micrometer and above. The gene expression of MMP-3 was also suppressed. The expression of TIMP-1 was significantly increased by DHEA-pyruvate at concentration of 50 micrometer. The effects of DHEA-pyruvate were also prominent in the presence of IL-1, in which IL-1induced gene expressions of not only MMP-1, but also MMP-3 were suppressed at a lower concentration of 10 micrometer and 50 micrometer, respectively. In enzyme activity measurement, the results came in line with the results obtained by RT-PCR, which means DHEA-pyruvate influences on the gene transcription level. CONCLUSION: Our study clearly demonstrated that DHEA-pyruvate has the ability to modulate the imbalance between MMPs and TIMP-1 during osteoarthritis at the transcription level, suggesting its protective role against loss of articular cartilage.
Cartilage ; Cartilage, Articular ; Chondrocytes* ; Dehydroepiandrosterone ; DNA ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; Humans* ; Interleukin-1 ; Knee ; Matrix Metalloproteinases ; Osteoarthritis ; Tissue Inhibitor of Metalloproteinase-1

Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. Activating transcription factor 3 (ATF3) is associated with apoptosis in human colon cancer cells. This study was performed to investigate the molecular mechanism by which NAR stimulates ATF3 expression and apoptosis in human colon cancer cells. NAR reduced the cell viability and induced an apoptosis in human colon cancer cells. ATF3 overexpression increased NAR-mediated cleaved PARP, while ATF3 knockdown attenuated the cleavage of PARP by NAR. NAR increased ATF3 expression in both protein and mRNA level, and increased the luciferase activity of ATF3 promoter in a dose-dependent manner. The responsible region for ATF3 transcriptional activation by NAR is located between -317 and -148 of ATF3 promoter. p38 inhibition blocked NAR-mediated ATF3 expression, its promoter activation and apoptosis. The results suggest that NAR induces apoptosis through p38-dependent ATF3 activation in human colon cancer cells.
Activating Transcription Factor 3 ; Apoptosis* ; Cell Survival ; Citrus paradisi ; Colon* ; Colonic Neoplasms* ; Flavonoids ; Humans* ; Luciferases ; RNA, Messenger ; Transcriptional Activation

OBJECTIVES: To ascertain whether some result of hematological examination could be as reference data for health management of welders. METHOD: The authors conducted the hematological examination of 1,018 welders and 531 control workers of a shipbuilding industry in Ulsan using automatic blood analyzer. RESULTS: The WBC count of welders was lower than that of control on controlling the age and the duration of employment, but changes of other blood cells were not observed. CONCLUSION: We could use the results of hematological examination such as WBC counts as an indicator for subtle changes of health status of welders.
Blood Cells ; Employment ; Ulsan

No abstract available.
Hormone Replacement Therapy ; Humans ; Incheon* ; Osteoporosis* ; Physicians, Primary Care* ; Primary Health Care*

Fexofenadine is useful in various allergic disease treatment.However,the pharmacokinetic variability information and quantitative factor identification of fexofenadine are very lacking.This study aimed to verify the validity of previously proposed genetic factors through fexofenadine population pharmaco-kinetic modeling and to explore the quantitative correlations affecting the pharmacokinetic variability.Polymorphisms of the organic-anion-transporting-polypeptide(OATP)1B1 and 2B1 have been proposed to be closely related to fexofenadine pharmacokinetic diversity.Therefore,modeling was performed using fexofenadine oral exposure data according to the OATP1B1-and 2B1-polymorphisms.OATP1B1 and 2B1 were identified as effective covariates of clearance(CL/F)and distribution volume(V/F)-CL/F,respectively,in fexofenadine pharmacokinetic variability.CL/F and average steady-state plasma con-centration of fexofenadine differed by up to 2.17-and 2.20-folds,respectively,depending on the OATP1B1 polymorphism.Among the individuals with different OATP2B1 polymorphisms,the CL/F and V/F differed by up to 1.73-and 2.00-folds,respectively.Ratio of the areas under the curves following single-and multiple-administrations,and the cumulative ratio were significantly different between OATP1B1-and 2B1-polymorphism groups.Based on quantitative prediction comparison through a model-based approach,OATP1B1 was confirmed to be relatively more important than 2B1 regarding the degree of effect on fexofenadine pharmacokinetic variability.Based on the established pharmacokinetic-pharmacodynamic relationship,the difference in fexofenadine efficacy according to genetic poly-morphisms of OATP1B1 and 2B1 was 1.25-and 0.87-times,respectively,and genetic consideration of OATP1B1 was expected to be important in the pharmacodynamics area as well.This population phar-macometrics study will be a very useful starting point for fexofenadine precision medicine.