Background: An increased incidence of hair loss disorders has been noted among patients with coronavirus disease 2019 (COVID-19) and individuals vaccinated against COVID-19. However, research involving large populations on this topic is lacking. Objective: To investigate the risks associated with developing hair loss disorders in patients with COVID-19 and individuals vaccinated against COVID-19. Methods: This nationwide, population-based, cross-sectional study included patients diagnosed with COVID-19 and healthy individuals without a history of COVID-19 infection registered in the Korean National Health Insurance Service (NHIS) database between January 1, 2021, and December 31, 2021. COVID-19 infection and vaccine databases were integrated using this NHIS database. The odds ratios of hair loss disorders were compared using multivariate logistic regression models. Results: COVID-19 infection was associated with an increased risk of total alopecia (adjusted odds ratio [aOR], 1.076; 95% confidence interval [CI], 1.002–1.156), although this association was not significant after propensity score matching. No significant associations were found between COVID-19 infection and alopecia areata or telogen effluvium. However, COVID-19 vaccination was positively correlated with total alopecia (aOR, 1.266; 95% CI, 1.191–1.346), alopecia areata (aOR, 1.243; 95% CI, 1.154–1.339), and telogen effluvium (aOR, 1.495; 95% CI, 1.133–1.974). Conclusion COVID-19 vaccination was positively correlated with hair loss disorders but not COVID-19 infection. However, given the advantages of vaccines in reducing COVID-19 mortality and morbidity, alopecia may be relatively reversible and less severe. Physicians need to understand the benefits and possible side effects of the COVID-19 vaccine.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates.Two high-risk clones, ST235 (N = 41) and ST111 (N = 20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metalloβ-lactamase (MBL) genes, blaIMP-6 (N = 38), blaVIM-2 (N = 3), and blaNDM-1 (N = 2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene–negative isolates. Conclusions Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates.Two high-risk clones, ST235 (N = 41) and ST111 (N = 20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metalloβ-lactamase (MBL) genes, blaIMP-6 (N = 38), blaVIM-2 (N = 3), and blaNDM-1 (N = 2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene–negative isolates. Conclusions Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates.Two high-risk clones, ST235 (N = 41) and ST111 (N = 20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metalloβ-lactamase (MBL) genes, blaIMP-6 (N = 38), blaVIM-2 (N = 3), and blaNDM-1 (N = 2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene–negative isolates. Conclusions Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates.Two high-risk clones, ST235 (N = 41) and ST111 (N = 20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metalloβ-lactamase (MBL) genes, blaIMP-6 (N = 38), blaVIM-2 (N = 3), and blaNDM-1 (N = 2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene–negative isolates. Conclusions Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

Purpose: Human breast milk (HBM) contains immune components that produced and delivered from the mother along with nutrients necessary for the baby. MicroRNA (miRNA) is a small noncoding RNA molecule, that is used as an ideal biomarker for diagnosis and prognosis of various diseases and are more abundant in HBM. We analyzed and compared the immune components and miRNAs of HBM. Methods: HBM were collected from 20 healthy breastfeeding mothers. We measured the amount of lactoferrin, lysozyme, and immunoglobulin A (IgA) and extracted the miRNAs from each breast milk samples. Next, the top 5 and bottom 5 expressed miRNAs were compared and analyzed based on the amounts of the 3 immune components. Results: The mean levels and ranges of lactoferrin, lysozyme, and IgA were 6.33 (2.24–14.77)×106 ng/mL, 9.90 (1.42–17.59)×107 pg/mL, and 6.64 (0.48–20.01)×105 ng/mL, respectively. The miRNAs concentration per 1 mL of skim milk was 40.54 (14.95–110.01) ng/μL. Comparing the bottom 5 and top 5 groups of each immune component, 19 miRNAs were significantly upregulated (6, 9, and 4 targeting lactoferrin, lysozyme, and IgA, respectively) and 21 were significantly downregulated (4, 9, and 8 targeting lactoferrin, lysozyme, and IgA, respectively). There were no miRNAs that were expressed significantly higher or lower in common to all 3 components.However, 2 and 3 miRNAs were commonly overexpressed and underexpressed, in the top 5 groups of lysozyme and IgA concentrations. Conclusion We identified the immune components and miRNAs in breast milk and found that each individual has different ingredients.

Purpose: Human breast milk (HBM) contains immune components that produced and delivered from the mother along with nutrients necessary for the baby. MicroRNA (miRNA) is a small noncoding RNA molecule, that is used as an ideal biomarker for diagnosis and prognosis of various diseases and are more abundant in HBM. We analyzed and compared the immune components and miRNAs of HBM. Methods: HBM were collected from 20 healthy breastfeeding mothers. We measured the amount of lactoferrin, lysozyme, and immunoglobulin A (IgA) and extracted the miRNAs from each breast milk samples. Next, the top 5 and bottom 5 expressed miRNAs were compared and analyzed based on the amounts of the 3 immune components. Results: The mean levels and ranges of lactoferrin, lysozyme, and IgA were 6.33 (2.24–14.77)×106 ng/mL, 9.90 (1.42–17.59)×107 pg/mL, and 6.64 (0.48–20.01)×105 ng/mL, respectively. The miRNAs concentration per 1 mL of skim milk was 40.54 (14.95–110.01) ng/μL. Comparing the bottom 5 and top 5 groups of each immune component, 19 miRNAs were significantly upregulated (6, 9, and 4 targeting lactoferrin, lysozyme, and IgA, respectively) and 21 were significantly downregulated (4, 9, and 8 targeting lactoferrin, lysozyme, and IgA, respectively). There were no miRNAs that were expressed significantly higher or lower in common to all 3 components.However, 2 and 3 miRNAs were commonly overexpressed and underexpressed, in the top 5 groups of lysozyme and IgA concentrations. Conclusion We identified the immune components and miRNAs in breast milk and found that each individual has different ingredients.

Purpose: Human breast milk (HBM) contains immune components that produced and delivered from the mother along with nutrients necessary for the baby. MicroRNA (miRNA) is a small noncoding RNA molecule, that is used as an ideal biomarker for diagnosis and prognosis of various diseases and are more abundant in HBM. We analyzed and compared the immune components and miRNAs of HBM. Methods: HBM were collected from 20 healthy breastfeeding mothers. We measured the amount of lactoferrin, lysozyme, and immunoglobulin A (IgA) and extracted the miRNAs from each breast milk samples. Next, the top 5 and bottom 5 expressed miRNAs were compared and analyzed based on the amounts of the 3 immune components. Results: The mean levels and ranges of lactoferrin, lysozyme, and IgA were 6.33 (2.24–14.77)×106 ng/mL, 9.90 (1.42–17.59)×107 pg/mL, and 6.64 (0.48–20.01)×105 ng/mL, respectively. The miRNAs concentration per 1 mL of skim milk was 40.54 (14.95–110.01) ng/μL. Comparing the bottom 5 and top 5 groups of each immune component, 19 miRNAs were significantly upregulated (6, 9, and 4 targeting lactoferrin, lysozyme, and IgA, respectively) and 21 were significantly downregulated (4, 9, and 8 targeting lactoferrin, lysozyme, and IgA, respectively). There were no miRNAs that were expressed significantly higher or lower in common to all 3 components.However, 2 and 3 miRNAs were commonly overexpressed and underexpressed, in the top 5 groups of lysozyme and IgA concentrations. Conclusion We identified the immune components and miRNAs in breast milk and found that each individual has different ingredients.

Pedicle ossification is a rare but significant complication following mandibular reconstruction using a fibular free flap (FFF), a technique widely employed in maxillofacial surgery due to its reliable vascularized bone supply and low donor site morbidity. The FFF supports dental implantation and prosthetic rehabilitation, with its vascularized periosteum enhancing osteogenic potential. Despite these advantages, unexpected ossification of the flap’s vascular pedicle may occur, potentially mimicking tumor recurrence and causing diagnostic uncertainty. This case report describes a 38-year-old male with left buccal squamous cell carcinoma treated by wide excision, modified radical neck dissection, and reconstruction using a radial forearm free flap. Postoperative radiotherapy led to complications including trismus and alveolar bone exposure, culminating in a pathological mandibular fracture. Mandibular reconstruction was performed using an FFF. Over 4 years of follow-up, computed tomography revealed ossification within the vascular pedicle. Notably, the patient remained asymptomatic, maintaining normal speech and swallowing without functional impairment. Pedicle ossification may present radiographically as a suspicious bony change misinterpreted as tumor recurrence. Routine follow-up imaging such as computed tomography is essential for differentiation. Although trismus, bony swelling, or pain may occur, surgical intervention is typically deferred unless symptoms develop. Therefore, careful clinical assessment and monitoring remain crucial.

Respiratory epithelial adenomatoid hamartoma (REAH) in the head and neck is a rare benign lesion containing glandular tissue covered with ciliated respiratory epithelium. In the head and neck, REAH of the nasal cavity, paranasal sinuses, and nasopharynx have been reported in literature. Due to rareness of REAH and insufficient knowledge of its imaging features, the diagnosis can be challenging when we encounter a non-specific cystic mass at an uncommon site in the head or neck. Here, we report the case of a pathologically confirmed REAH showing a cystic mass centered at the buccal space (retromaxillary fat pad) with CT and MRI findings.