National cohort data collected during the coronavirus disease 2019 (COVID-19) delta and omicron periods in Korea revealed a lower risk of severe infection in recipients of three doses of the COVID-19 vaccine (adjusted odds ratio [aOR], 0.05–0.08). The risk of death was reduced during the omicron period compared to the delta period (aOR, 0.75; 95% confidence interval, 0.67–0.84).

Background: Some working conditions may pose a higher physical or psychological demand to pregnant women leading to increased risks of pregnancy complications. Objectives: We assessed the association of woman's employment status and the industrial classification with obstetric complications. Methods: We conducted a national population study using the National Health Information Service database of Republic of Korea. Our analysis encompassed 1,316,310 women who experienced first-order live births in 2010–2019. We collected data on the employment status and the industrial classification of women, as well as their diagnoses of preeclampsia (PE) and gestational diabetes mellitus (GDM) classified as A1 (well controlled by diet) or A2 (requiring medication). We calculated odds ratios (aORs) of complications per employment, and each industrial classification was adjusted for individual risk factors. Results: Most (64.7%) were in employment during pregnancy. Manufacturing (16.4%) and the health and social (16.2%) work represented the most prevalent industries. The health and social work exhibited a higher risk of PE (aOR = 1.11, 95% confidence interval [CI]: 1.03–1.21), while the manufacturing industry demonstrated a higher risk of class A2 GDM (1.20, 95% CI: 1.03–1.41) than financial intermediation. When analyzing both classes of GDM, women who worked in public administration and defense/social security showed higher risk of class A1 GDM (1.04, 95% CI: 1.01, 1.07). When comparing high-risk industries with nonemployment, the health and social work showed a comparable risk of PE (1.02, 95% CI: 0.97, 1.07). Conclusion Employment was associated with overall lower risks of obstetric complications. Health and social service work can counteract the healthy worker effect in relation to PE. This highlights the importance of further elucidating specific occupational risk factors within the high-risk industries.

OBJECTIVES: Limited evidence is available regarding the impact of paternal occupation and its combined effect with maternal occupation on preterm birth. Therefore, we assessed the association of maternal and paternal occupations with preterm birth. METHODS: We used the national birth data of Korea between 2010 and 2020. Parental occupations were divided into 5 categories: (1) managers; (2) professionals, technicians, and related workers; (3) clerks and support workers; (4) service and sales workers; and (5) manual workers. A multinomial logistic regression model was used to calculate the adjusted odds ratios (aORs) of extremely, very, and moderate-to-late preterm births per occupational category considering individual risk factors. RESULTS: For the 4,004,976 singleton births, 40.2% of mothers and 95.5% of fathers were employed. Compared to non-employment, employment was associated with a lower risk of preterm birth. Among employed mothers, service and sales occupations were associated with a higher risk of preterm birth than managerial occupations (aOR, 1.06; 95% confidence interval [CI], 1.01 to 1.10 for moderate-to-late preterm births). The father’s manual occupation was associated with a higher risk of preterm birth (aOR, 1.09; 95% CI, 1.05 to 1.13 for moderate-to-late preterm) than managerial occupations. When both parents had high-risk occupations, the risk of preterm birth was higher than in cases where only the mother or neither of the parents had a high-risk occupation. CONCLUSIONS Paternal occupation was associated with preterm birth regardless of maternal employment and occupation and modified the effect of maternal occupation. Detailed occupational environment data are needed to identify the paternal exposures that increase the risk.

Objectives: : We estimated the overall and age-specific percentages of the Korean population with presumed immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as of April 2022 using the national registry. Methods: : We used the national coronavirus disease 2019 (COVID-19) infection and vaccination registry from South Korea, as described to define individuals with a previous history of COVID-19 infection, vaccination, or both, as persons with presumed immunity. Results: : Of a total of 53,304,627 observed persons, 24.4% had vaccination and infection, 58.1% had vaccination and no infection, 7.6% had infection and no vaccination, and 9.9% had no immunity. The SARS-CoV-2 Omicron variant emerged at a time when the presumed population immunity ranged from 80% to 85%; however, nearly half of the children were presumed to have no immunity. Conclusion : We report a gap in population immunity, with lower presumed protection in children than in adults. The approach presented in this work can provide valuable informed tools to assist vaccine policy-making at a national level.

In November 2021, 14 international travel-related severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 (omicron) variant of concern (VOC) patients were detected in South Korea. Epidemiologic investigation revealed community transmission of the omicron VOC. A total of 80 SARS-CoV-2 omicron VOC-positive patients were identified until December 10, 2021 and 66 of them reported no relation to the international travel.There may be more transmissions with this VOC in Korea than reported.

The heterogeneity of cancer makes it difficult to predict the prognosis of treatment. There is still a lack of preclinical model systems that reflect the clinical characteristics of patients who have heterogenetic tumors. Advances in 3-dimentional (3D) cell culture are leading to discoveries that occur in the development and progression of cancer that has not been known. There are many models including patient-derived xenograft, patient-derived organoid and spheroid, patient-derived explant, scaffold-based model, and system-based model. Each 3D model has its strengths and limitations. One model cannot answer every question, so it seems most reasonable to approach multiple models when studying cancer heterogeneity. Hopefully, 3D tumor modeling will make tremendous progress on this path by fusion of innovative biomaterials and advanced modeling techniques that can partially mimic the heterogeneous environment of real tumors.

Background: Direct-to-implant (DTI) breast reconstruction after nipple-sparing mastectomy (NSM) with the use of acellular dermal matrix (ADM) provides reliable outcomes; however, the use of ADM is associated with a higher risk of complications. We analyzed our experiences of post-NSM DTI without ADM and identified the predictive factors of adverse surgical outcomes. Methods: Patients who underwent NSM and immediate DTI or two-stage tissue expander (TE) breast reconstruction from 2009 to 2020 were enrolled. Predictors of adverse endpoints were analyzed. Results: There were 100 DTI and 29 TE reconstructions. The TE group had a higher rate of postmastectomy radiotherapy (31% vs. 11%; P=0.009), larger specimens (317.37±176.42 g vs. 272.08±126.33 g; P=0.047), larger implants (360.84±85.19 g vs. 298.83±81.13 g; P=0.004) and a higher implant/TE exposure ratio (10.3% vs. 1%; P=0.035). In DTI reconstruction, age over 50 years (odds ratio [OR], 5.43; 95% confidence interval [CI], 1.50–19.74; P=0.010) and a larger mastectomy weight (OR, 1.65; 95% CI, 1.08–2.51; P=0.021) were associated with a higher risk of acute complications. Intraoperative radiotherapy for the nipple-areolar complex increased the risk of acute complications (OR, 4.05; 95% CI, 1.07–15.27; P=0.039) and the likelihood of revision surgery (OR, 5.57; 95% CI, 1.25–24.93; P=0.025). Conclusions Immediate DTI breast reconstruction following NSM is feasible in Asian patients with smaller breasts.

Background/Aims: Direct‐acting antivirals (DAAs) have been approved for hepatitis C virus (HCV) treatment in patients with end-stage renal disease (ESRD) on hemodialysis. Nevertheless, the complicated comedications and their potential drug-drug interactions (DDIs) with DAAs might limit clinical practice in this special population. Methods: The number, class, and characteristics of comedications and their potential DDIs with five DAA regimens were analyzed among HCV-viremic patients from 23 hemodialysis centers in Taiwan. Results: Of 2,015 hemodialysis patients screened in 2019, 169 patients seropositive for HCV RNA were enrolled (mean age, 65.6 years; median duration of hemodialysis, 5.8 years). All patients received at least one comedication (median number, 6; mean class number, 3.4). The most common comedication classes were ESRD-associated medications (94.1%), cardiovascular drugs (69.8%) and antidiabetic drugs (43.2%). ESRD-associated medications were excluded from DDI analysis. Sofosbuvir/velpatasvir/voxilaprevir had the highest frequency of potential contraindicated DDIs (red, 5.6%), followed by glecaprevir/pibrentasvir (4.0%), sofosbuvir/ledipasvir (1.3%), sofosbuvir/velpatasvir (1.3%), and elbasvir/grazoprevir (0.3%). For potentially significant DDIs (orange, requiring close monitoring or dose adjustments), sofosbuvir/velpatasvir/voxilaprevir had the highest frequency (19.9%), followed by sofosbuvir/ledipasvir (18.2%), glecaprevir/pibrentasvir (12.6%), sofosbuvir/velpatasvir (12.6%), and elbasvir/grazoprevir (7.3%). Overall, lipid-lowering agents were the most common comedication class with red-category DDIs to all DAA regimens (n=62), followed by cardiovascular agents (n=15), and central nervous system agents (n=10). Conclusions HCV-viremic patients on hemodialysis had a very high prevalence of comedications with a broad spectrum, which had varied DDIs with currently available DAA regimens. Elbasvir/grazoprevir had the fewest potential DDIs, and sofosbuvir/velpatasvir/voxilaprevir had the most potential DDIs.

Background: Direct-to-implant (DTI) breast reconstruction after nipple-sparing mastectomy (NSM) with the use of acellular dermal matrix (ADM) provides reliable outcomes; however, the use of ADM is associated with a higher risk of complications. We analyzed our experiences of post-NSM DTI without ADM and identified the predictive factors of adverse surgical outcomes. Methods: Patients who underwent NSM and immediate DTI or two-stage tissue expander (TE) breast reconstruction from 2009 to 2020 were enrolled. Predictors of adverse endpoints were analyzed. Results: There were 100 DTI and 29 TE reconstructions. The TE group had a higher rate of postmastectomy radiotherapy (31% vs. 11%; P=0.009), larger specimens (317.37±176.42 g vs. 272.08±126.33 g; P=0.047), larger implants (360.84±85.19 g vs. 298.83±81.13 g; P=0.004) and a higher implant/TE exposure ratio (10.3% vs. 1%; P=0.035). In DTI reconstruction, age over 50 years (odds ratio [OR], 5.43; 95% confidence interval [CI], 1.50–19.74; P=0.010) and a larger mastectomy weight (OR, 1.65; 95% CI, 1.08–2.51; P=0.021) were associated with a higher risk of acute complications. Intraoperative radiotherapy for the nipple-areolar complex increased the risk of acute complications (OR, 4.05; 95% CI, 1.07–15.27; P=0.039) and the likelihood of revision surgery (OR, 5.57; 95% CI, 1.25–24.93; P=0.025). Conclusions Immediate DTI breast reconstruction following NSM is feasible in Asian patients with smaller breasts.