Objectives: The present paper aimed to examine whether an aging workforce is associated with an increase in work-related fatal injuries and to explore the underlying reasons for this potential increase.Material and methodsAged workers were defined as those who were at least 55 years old. Work-related fatalities were assessed in aged and young workers who were registered with the workers' compensation system in 2021 in the Republic of Korea. Total waged workers, based on raw data from the Local Area Labor Force Survey in 2021, were used as the denominator to estimate the work-related fatality rates. Results: Most work-related fatalities in the aged workers occurred among individuals working in the “construction sector” (58.9%), those with “elementary occupations (unskilled workers)” (46.1%), and those with the employment status of “daily worker” (60.8%). The estimated incidence (0.973/10,000) of work-related fatalities among aged workers was about four times higher than that (0.239/10,000) among younger workers. “Falling,” “collision,” “struck by an object,” and “trip and slip” were more frequent types of work-related fatalities among aged workers relative to young workers. The category of “buildings, structures, and surfaces” was a more frequent cause of work-related fatalities among aged workers than among young workers. Conclusions Aged workers had a higher incidence of work-related fatalities than young workers. Frequent engagement in precarious employment and jobs, coupled with the greater physical vulnerability of aged workers, were likely causes of their higher level of work-related fatal injuries.

Purpose: This study was conducted to develop a convolutional neural network (CNN) algorithm that can diagnose cervical foraminal stenosis using oblique radiographs and evaluate its accuracy. Materials and Methods: A total of 997 patients who underwent cervical MRI and cervical oblique radiographs within a 3-month interval were included. Oblique radiographs were labeled as “foraminal stenosis” or “no foraminal stenosis” according to whether foraminal stenosis was present in the C2–T1 levels based on MRI evaluation as ground truth. The CNN model involved data augmentation, image preprocessing, and transfer learning using DenseNet161. Visualization of the location of the CNN model was performed using gradient-weight class activation mapping (Grad-CAM). Results: The area under the curve (AUC) of the receiver operating characteristic curve based on DenseNet161 was 0.889 (95% confidence interval, 0.851–0.927). The F1 score, accuracy, precision, and recall were 88.5%, 84.6%, 88.1%, and 88.5%, respectively.The accuracy of the proposed CNN model was significantly higher than that of two orthopedic surgeons (64.0%, p<0.001; 58.0%, p<0.001). Grad-CAM analysis demonstrated that the CNN model most frequently focused on the foramen location for the determination of foraminal stenosis, although disc space was also frequently taken into consideration. Conclusion A CNN algorithm that can detect neural foraminal stenosis in cervical oblique radiographs was developed. The AUC, F1 score, and accuracy were 0.889, 88.5%, and 84.6%, respectively. With the current CNN model, cervical oblique radiography could be a more effective screening tool for neural foraminal stenosis.

Background/Aims: Several prediction models for evaluating the prognosis of nonmetastatic resected pancreatic ductal adenocarcinoma (PDAC) have been developed, and their performances were reported to be superior to that of the 8th edition of the American Joint Committee on Cancer (AJCC) staging system. We developed a prediction model to evaluate the prognosis of resected PDAC and externally validated it with data from a nationwide Korean database. Methods: Data from the Surveillance, Epidemiology and End Results (SEER) database were utilized for model development, and data from the Korea Tumor Registry System-Biliary Pancreas (KOTUS-BP) database were used for external validation. Potential candidate variables for model development were age, sex, histologic differentiation, tumor location, adjuvant chemotherapy, and the AJCC 8th staging system T and N stages. For external validation, the concordance index (C-index) and time-dependent area under the receiver operating characteristic curve (AUC) were evaluated. Results: Between 2004 and 2016, data from 9,624 patients were utilized for model development, and data from 3,282 patients were used for external validation. In the multivariate Cox proportional hazard model, age, sex, tumor location, T and N stages, histologic differentiation, and adjuvant chemotherapy were independent prognostic factors for resected PDAC. After an exhaustive search and 10-fold cross validation, the best model was finally developed, which included all prognostic variables. The C-index, 1-year, 2-year, 3-year, and 5-year time-dependent AUCs were 0.628, 0.650, 0.665, 0.675, and 0.686, respectively. Conclusions The survival prediction model for resected PDAC could provide quantitative survival probabilities with reliable performance. External validation studies with other nationwide databases are needed to evaluate the performance of this model.

Apolipoprotein E (apoE) plays a role in various physiological functions including lipid transport, synaptic plasticity, and immune modulation.Epidemiological studies suggest that the apoE4 allele increases the risk of post-traumatic sequelae. This study was performed to investigate regionspecific effects of the apoE4 isoform on post-traumatic neurodegeneration. Two focal brain injuries were introduced separately in the motor cortex and hippocampus of apoE4 knock-in, apoE3 knock-in, apoE knockout, and wild-type (WT) mice. Western blotting showed that the expression levels of pre-synaptic and post-synaptic markers at the recovery stage were lower in the hippocampal injury core in apoE4 mice, compared with apoE3 and WT mice. Fast glial activation (determined by immunohistochemistry with glial fibrillary acidic protein, ionized calcium binding adaptor molecule 1, and cluster of differentiation 45 antibodies) was characteristic of apoE4 mice with hippocampal injury penumbra. apoE4-specific changes were not observed after cortical injury. The intensity of microglial activation in the hippocampus was inversely correlated with the volume of injury reduction on sequential magnetic resonance imaging examinations, when validated using matched samples. These findings indicate that the effects of the interaction between apoE4 and focal brain damage are specific to the hippocampus. Manipulation of inflammatory cell responses could be beneficial for reducing post-traumatic hippocampal neurodegeneration in apoE4 carriers.

Methemoglobinemia is rare. It is classified into two types: congenital methemoglobinemia and acquired methemoglobinemia. Methemoglobin is incapable of binding oxygen, leading to complications such as cyanosis, dyspnea, headache, and heart failure. In the present case, a 35-year-old man with congenital methemoglobinemia underwent general anesthesia for thyroidectomy. The patient was diagnosed with hemoglobin M at 7 years of age. Ventilation was performed with FiO2 1.0. Arterial blood gas analysis showed that the pH was 7.4, PaO 2 439 mmHg, PaCO2 40.5 mmHg, oxyhemoglobin level of 83.2%, and methemoglobin level of 15.5%. The patient had a stable course, although cyanosis was observed during surgery.

Apolipoprotein E (apoE) plays a role in various physiological functions including lipid transport, synaptic plasticity, and immune modulation.Epidemiological studies suggest that the apoE4 allele increases the risk of post-traumatic sequelae. This study was performed to investigate regionspecific effects of the apoE4 isoform on post-traumatic neurodegeneration. Two focal brain injuries were introduced separately in the motor cortex and hippocampus of apoE4 knock-in, apoE3 knock-in, apoE knockout, and wild-type (WT) mice. Western blotting showed that the expression levels of pre-synaptic and post-synaptic markers at the recovery stage were lower in the hippocampal injury core in apoE4 mice, compared with apoE3 and WT mice. Fast glial activation (determined by immunohistochemistry with glial fibrillary acidic protein, ionized calcium binding adaptor molecule 1, and cluster of differentiation 45 antibodies) was characteristic of apoE4 mice with hippocampal injury penumbra. apoE4-specific changes were not observed after cortical injury. The intensity of microglial activation in the hippocampus was inversely correlated with the volume of injury reduction on sequential magnetic resonance imaging examinations, when validated using matched samples. These findings indicate that the effects of the interaction between apoE4 and focal brain damage are specific to the hippocampus. Manipulation of inflammatory cell responses could be beneficial for reducing post-traumatic hippocampal neurodegeneration in apoE4 carriers.

Methemoglobinemia is rare. It is classified into two types: congenital methemoglobinemia and acquired methemoglobinemia. Methemoglobin is incapable of binding oxygen, leading to complications such as cyanosis, dyspnea, headache, and heart failure. In the present case, a 35-year-old man with congenital methemoglobinemia underwent general anesthesia for thyroidectomy. The patient was diagnosed with hemoglobin M at 7 years of age. Ventilation was performed with FiO2 1.0. Arterial blood gas analysis showed that the pH was 7.4, PaO 2 439 mmHg, PaCO2 40.5 mmHg, oxyhemoglobin level of 83.2%, and methemoglobin level of 15.5%. The patient had a stable course, although cyanosis was observed during surgery.

Lipofibromatous hamartoma (LFH) is a rare tumor of the peripheral nerves, which usually involves the median nerve. The authors reported on two rare cases of carpal tunnel syndrome due to LFH of the median nerve. A 49-year-old female patient complained of the mass and symptoms consistent with LFH. Magnetic resonance imaging (MRI) showed typical LFH findings. The symptoms were successfully ameliorated with carpal tunnel release and external neurolysis. A 37-year-old female patient complained of weakening thumb abduction and the mass where the MRI showed atypical findings. Opponensplasty and debulking operations were performed after which thumb abduction was improved; however, neurological sequelae remained. LFH of the median nerve is managed on a case-by-case basis as treatment guidelines are not very clearly defined yet. However, the less invasive treatment such as carpal tunnel release and external neurolysis than more aggressive surgical treatment should be recommended as a treatment option.

OBJECTIVES: Dentists and dental hygienists undergo high levels of stress due to various factors and the burnout of health-care personnel is very important in the context of personal and social problems. Therefore, empirical research reflecting the social, cultural, and special circumstances of the medical environment is necessary. Here, we explore the causes and outcomes of burnout in dentists and dental hygienists and present ways to prevent burnout. METHODS: A cross-sectional research design was used to measure burnout of 141 dentists and 61 dental hygienists. A structured questionnaire containing the Maslach Burnout Inventory (MBI) was administered from May to June, 2018. Data were analyzed using SPSS 25.0, descriptive statistics, t-test, Mann-Whitney test, Kruskall-Wallis test, and multiple regression analysis. RESULTS: Each participant's MBI was measured in three aspects (emotional exhaustion, depersonalization, and personal accomplishment). The MBI scores of dentists with regards to their emotional exhaustion, depersonalization, and personal accomplishment were 24.8%, 34%, and 48.2%, respectively. Alternatively the scores of dental hygienists were 45.9%, 44.3% and 52.5%, respectively, for the same parameters. While the factors affecting the burnout of dentists and dental hygienists were different, it had a negative impact on the professional performance of both. CONCLUSIONS: According to the results of this study, Korean dentists and dental hygienists experience high levels of work-related burnouts. This can have adverse impacts on their personal health and that of their patients. Therefore, stress management is necessary in dentists and dental hygienists.
Dental Hygienists ; Dentists ; Depersonalization ; Empirical Research ; Humans ; Research Design ; Social Problems