A Radiomics-Based Model for Potentially More Accurate Identification of Subtypes of Breast Cancer Brain Metastases

Purpose@#Breast cancer brain metastases (BCBM) may involve subtypes that differ from the primary breast cancer lesion. This study aimed to develop a radiomics-based model that utilizes preoperative brain MRI for multiclass classification of BCBM subtypes and to investigate whether the model offers better prediction accuracy than the assumption that primary lesions and their BCBMs would be of the same subtype (non-conversion model) in an external validation set. @*Materials and Methods@#The training and external validation sets each comprised 51 cases (102 cases total). Four machine learning classifiers combined with three feature selection methods were trained on radiomic features and primary lesion subtypes for prediction of the following four subtypes: 1) hormone receptor (HR)+/human epidermal growth factor receptor 2 (HER2)-, 2) HR+/HER2+, 3) HR-/HER2+, and 4) triple-negative. After training, the performance of the radiomics-based model was compared to that of the non-conversion model in an external validation set using accuracy and F1-macro scores. @*Results@#The rate of discrepant subtypes between primary lesions and their respective BCBMs were 25.5% (n=13 of 51) in the training set and 23.5% (n=12 of 51) in the external validation set. In the external validation set, the accuracy and F1-macro score of the radiomics-based model were significantly higher than those of the non-conversion model (0.902 vs. 0.765, p=0.004; 0.861 vs. 0.699, p=0.002). @*Conclusion@#Our radiomics-based model represents an incremental advance in the classification of BCBM subtypes, thereby facilitating a more appropriate personalized therapy.

Matrix Metalloproteinase 1 as a Marker of Tonsil-Derived Mesenchymal Stem Cells to Assess Bone Marrow Cell Migration

BACKGROUND@#To achieve optimal bone marrow engraftment during bone marrow transplantation, migration of donor bone marrow cells (BMCs) toward the recipient’s bone marrow is critical. Despite the enhanced engraftment of BMCs by co-administration of mesenchymal stem cells (MSCs), the efficiency can be variable depending on MSC donor. The purpose of this study is to examine the functional heterogeneity of tonsil-derived MSCs (TMSCs) and to identify a marker to evaluate efficacy for the enhancement of BMC migration. @*METHODS@#To examine the donor-to-donor variation of TMSCs in potentiating BMC migration, we isolated TMSCs from 25 independent donors. Transcriptome of TMSCs and proteome of conditioned medium derived from TMSC were analyzed. @*RESULTS@#Enhanced BMC migration by conditioned medium derived from TMSCs was variable depending on TMSC donor. The TMSCs derived from 25 donors showed distinct expression profiles compared with other cells, including fibroblasts, adipose-derived MSCs and bone marrow–derived MSCs. TMSCs were distributed in two categories: high- and low-efficacy groups for potentiating BMC migration. Transcriptome analysis of TMSCs and proteome profiles of conditioned medium derived from TMSCs revealed higher expression and secretion of matrix metalloproteinase (MMP) 1 in the high-efficacy group. MMP1 knockdown in TMSCs abrogated the supportive efficacy of conditioned medium derived from TMSC cultures in BMC migration. @*CONCLUSION@#These data suggest that secreted MMP1 can be used as a marker to evaluate the efficacy of TMSCs in enhancing BMC migration. Furthermore, the strategy of analyzing transcriptomes and proteomes of the MSCs may be useful to set the standard for donor variation.

Korean treatment recommendations for patients with axial spondyloarthritis

We aimed to develop evidence-based recommendations for treating axial spondylarthritis (axSpA) in Korea. The development committee was constructed, key clinical questions were determined, and the evidence was searched through online databases including MEDLINE, Embase, Cochrane, KoreaMed, and Kmbase. Systematic literature reviews were conducted, quality of evidence was determined, and draft recommendations were formulated according to the Grading of Recommendations Assessment, Development, and Evaluations methodology. Recommendations that reached 80% consensus among a voting panel were finalized. Three principles and 21 recommendations were determined. Recommendations 1 and 2 pertain to treatment strategies, regular disease status assessment, and rheumatologist-steered multidisciplinary management. Recommendations 3 and 4 strongly recommend patient education, exercise, and smoking cessation. Recommendations 5–12 address pharmacological treatment of active disease using nonsteroidal anti-inflammatory drugs, glucocorticoids, sulfasalazine, biologics, and Janus kinase inhibitors. Recommendations 13–16 address treatment in stable disease. We suggest against spa and acupuncture as therapies (Recommendation 17). Recommendations 18 and 19 pertain to total hip arthroplasty and spinal surgery. Monitoring of comorbidities and drug toxicities are recommended (Recommendations 20 and 21). Recommendations for axSpA treatment in a Korean context were developed based on comprehensive clinical questions and evidence. These are intended to guide best practice in the treatment of axSpA.

Inflammation is responsible for systemic bone loss in patients with seropositive rheumatoid arthritis treated with rituximab

Background/Aims@#We investigated the effect of rituximab on systemic bone metabolism in patients with seropositive rheumatoid arthritis (RA). @*Methods@#Twenty seropositive patients with RA were enrolled and administered one cycle of rituximab. If RA became active for > 6 months after the first rituximab cycle, a second cycle was initiated; otherwise, no additional treatment was administered. Patients were divided into two groups according to the number of rituximab treatment cycles. @*Results@#In patients treated with a second cycle, the total hip bone mineral density (BMD) was clinically low, whereas the serum levels of receptor activator of nuclear factor kappa-B ligand (RANKL) were increased at 12 months. BMD in patients treated with one cycle did not change at 12 months, whereas serum RANKL levels decreased at all time points. DAS28 activity improved in both groups from baseline to 4 months; however, from 4 to 12 months, DAS28 activity worsened in the develgroup with the second cycle but remained stable in the group with one cycle. @*Conclusions@#Systemic inflammation, reflected by increased disease activity, may be responsible for the increase in RANKL levels, which causes systemic bone loss in rituximab-treated patients with RA. Although rituximab affects inflammation, it does not seem to alter systemic bone metabolism in RA.

How many times should we repeat measurements of the ultrasound-guided attenuation parameter for evaluating hepatic steatosis?

Purpose@#This retrospective study aimed to determine the number of times the ultrasound-guided attenuation parameter (UGAP) should be measured during the evaluation of hepatic steatosis. @*Methods@#Patients with suspected nonalcoholic fatty liver disease who underwent two UGAP repetition protocols (six-repetition [UGAP_6] and 12-repetition [UGAP_12]) and measurement of the controlled attenuation parameter (CAP) using transient elastography between October 2020 and June 2021 were enrolled. The mean attenuation coefficient (AC), interquartile range (IQR)/median, and coefficient of variance (CV) of the two repetition protocols were compared using the paired t test. Moreover, the diagnostic performances of UGAP_6 and UGAP_12 were compared using the area under the receiver operating characteristic (AUROC) curve, considering the CAP value as a reference standard. @*Results@#The study included 160 patients (100 men; mean age, 50.9 years). There were no significant differences between UGAP_6 and UGAP_12 (0.731±0.116 dB/cm/MHz vs. 0.734±0.113 dB/cm/MHz, P=0.156) and mean CV (7.6±0.3% vs. 8.0±0.3%, P=0.062). However, the mean IQR/median of UGAP_6 was significantly lower than that of UGAP_12 (8.9%±6.0% vs. 9.8%±5.2%, P=0.012). In diagnosing the hepatic steatosis stage, UGAP_6 and UGAP_12 yielded comparable AUROCs (≥S1, 0.908 vs. 0.897, P=0.466; ≥S2, 0.883 vs. 0.897, P=0.126; S3, 0.832 vs. 0.834, P=0.799). @*Conclusion@#UGAP had high diagnostic performance in diagnosing hepatic steatosis, regardless of the number of repetitions (six repetitions vs. 12 repetitions), with maintained reliability. Therefore, six UGAP measurements seem sufficient for evaluating hepatic steatosis using UGAP.

Bilateral tension pneumothoraces in a preterm low-birthweight newborn: tube thoracostomy using four 7-French latex catheters performed by an emergency physician

Neonatal tension pneumothorax is life-threatening. A tension pneumothorax on the right side was detected on a newborn boy weighing 2,380 g, who was born at 35 weeks of gestation. Given the unavailability of an on-duty thoracic surgeon and appropriately sized chest tubes in the neonatal intensive care unit, an emergency physician performed closed thoracostomy using two 7-French latex catheters. Immediately after the re-expansion of the right lung, left tension pneumothorax was newly detected. Two more 7-French latex catheters were inserted, relieving the left lesion. We consider that the right pneumothorax occurred due to the mixture of spontaneous rupture of the subpleural blebs and barotrauma during the initial positive pressure ventilation, while the left lesion did due to the high-flow oscillatory ventilation. Despite the limited availability of devices in the present case, a favorable outcome was achieved by the use of alternative catheters, which were chosen by the emergency physician.

Qualitative and Quantitative Magnetic Resonance Imaging Phenotypes May Predict CDKN2A/B Homozygous Deletion Status in Isocitrate Dehydrogenase-Mutant Astrocytomas:A Multicenter Study

Objective@#Cyclin-dependent kinase inhibitor (CDKN)2A/B homozygous deletion is a key molecular marker of isocitrate dehydrogenase (IDH)-mutant astrocytomas in the 2021 World Health Organization. We aimed to investigate whether qualitative and quantitative MRI parameters can predict CDKN2A/B homozygous deletion status in IDH-mutant astrocytomas. @*Materials and Methods@#Preoperative MRI data of 88 patients (mean age ± standard deviation, 42.0 ± 11.9 years; 40 females and 48 males) with IDH-mutant astrocytomas (76 without and 12 with CDKN2A/B homozygous deletion) from two institutions were included. A qualitative imaging assessment was performed. Mean apparent diffusion coefficient (ADC), 5th percentile of ADC, mean normalized cerebral blood volume (nCBV), and 95th percentile of nCBV were assessed via automatic tumor segmentation.Logistic regression was performed to determine the factors associated with CDKN2A/B homozygous deletion in all 88 patients and a subgroup of 47 patients with histological grades 3 and 4. The discrimination performance of the logistic regression models was evaluated using the area under the receiver operating characteristic curve (AUC). @*Results@#In multivariable analysis of all patients, infiltrative pattern (odds ratio [OR] = 4.25, p = 0.034), maximal diameter (OR = 1.07, p = 0.013), and 95th percentile of nCBV (OR = 1.34, p = 0.049) were independent predictors of CDKN2A/B homozygous deletion. The AUC, accuracy, sensitivity, and specificity of the corresponding model were 0.83 (95% confidence interval [CI], 0.72–0.91), 90.4%, 83.3%, and 75.0%, respectively. On multivariable analysis of the subgroup with histological grades 3 and 4, infiltrative pattern (OR = 10.39, p = 0.012) and 95th percentile of nCBV (OR = 1.24, p = 0.047) were independent predictors of CDKN2A/B homozygous deletion, with an AUC accuracy, sensitivity, and specificity of the corresponding model of 0.76 (95% CI, 0.60–0.88), 87.8%, 80.0%, and 58.1%, respectively. @*Conclusion@#The presence of an infiltrative pattern, larger maximal diameter, and higher 95th percentile of the nCBV may be useful MRI biomarkers for CDKN2A/B homozygous deletion in IDH-mutant astrocytomas.

Treatment Sequence After Initiating Biologic Therapy for Patients With Rheumatoid Arthritis in Korea: A Nationwide Retrospective Cohort Study

Objective@#To evaluate treatment patterns and healthcare resource utilization (HCRU) after initiating biologic disease-modifying antirheumatic drugs (bDMARDs) in Korean patients with rheumatoid arthritis (RA). @*Methods@#Patients newly diagnosed with RA in 2014 were identified and followed up on using the Korean National Health Insurance Database until 2018. The initial line of therapy (LOT) or LOT1 included patients treated with conventional DMARDs (cDMARD). Patients who started a bDMARD were assigned to LOT2 bDMARD. Those who moved from a bDMARD to a Janus kinase inhibitor were assigned to LOT3. Analyzed outcomes were treatment patterns and HCRU in LOT2 bDMARD. @*Results@#The most prescribed initial bDMARD was a tumor necrosis factor inhibitor. Seventy-five percent of patients had changes in treatment after starting a bDMARD, such as addition/removal or switch of a DMARD, and transition to LOT3. For the first and second changes in LOT2 bDMARD, adding a cDMARD to a bDMARD was more common than switching to another bDMARD (7.98% vs. 2.93% for the first change, and 17.10% vs. 6.51% for the second change). Tocilizumab was the most common bDMARD that was switched to. Forty-eight percent of patients had at least one hospitalization after initiating bDMARDs. Of these patients, 64.3% were admitted due to RA-related reasons. @*Conclusion@#This real-world study provides information on treatment characteristics of RA patients in Korea after starting a bDMARD. In contrary to guidelines, cDMARD addition was more often than bDMARD switches in daily clinical practice.

Association of Depression With Early Occurrence of Postural Instability in Parkinson’s Disease

Objective@#Depression in Parkinson’s disease (PD) affects the quality of life of patients. Postural instability and gait disturbance are associated with the severity and prognosis of PD. We investigated the association of depression with axial involvement in early-stage PD patients. @*Methods@#This study involved 95 PD patients unexposed to antiparkinsonian drugs. After a baseline assessment for depression, the subjects were divided into a depressed PD group and a nondepressed PD group. Analyses were conducted to identify an association of depression at baseline with the following outcome variables: the progression to Hoehn and Yahr scale (H-Y) stage 3, the occurrence of freezing of gait (FOG), levodopa-induced dyskinesia, and wearing-off. The follow-up period was 53.40 ± 16.79 months from baseline. @*Results@#Kaplan–Meier survival curves for H-Y stage 3 and FOG showed more prominent progression to H-Y stage 3 and occurrences of FOG in the depressed PD group than in the nondepressed PD group (log-rank p = 0.025 and 0.003, respectively). Depression in drug-naïve, early-stage PD patients showed a significant association with the progression to H-Y stage 3 (hazard ratio = 2.55; 95% confidence interval = 1.32–4.93; p = 0.005), as analyzed by Cox regression analyses. In contrast, the occurrence of levodopa-induced dyskinesia and wearing-off did not differ between the two groups (log-rank p = 0.903 and 0.351, respectively). @*Conclusion@#Depression in drug-naïve, early-stage PD patients is associated with an earlier occurrence of postural instability. This suggests shared nondopaminergic pathogenic mechanisms and potentially enables the prediction of early development of postural instability.

The Effect of Blood Lipids, Type 2 Diabetes, and Body Mass Index on Parkinson’s Disease: A Korean Mendelian Randomization Study

Objective@#Associations between various metabolic conditions and Parkinson’s disease (PD) have been previously identified in epidemiological studies. We aimed to investigate the causal effect of lipid levels, type 2 diabetes mellitus (T2DM), and body mass index (BMI) on PD in a Korean population via Mendelian randomization (MR). @*Methods@#Two-sample MR analyses were performed with inverse-variance weighted (IVW), weighted median, and MR-Egger regression approaches. We identified genetic variants associated with lipid concentrations, T2DM, and BMI in publicly available summary statistics, which were either collected from genome-wide association studies (GWASs) or from meta-analyses of GWAS that targeted only Korean individuals or East Asian individuals, including Korean individuals. The outcome dataset was a GWAS on PD performed in a Korean population. @*Results@#From previous GWASs and meta-analyses, we selected single nucleotide polymorphisms as the instrumental variables. Variants associated with serum levels of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides, as well as with T2DM and BMI, were selected (n = 11, 19, 17, 89, and 9, respectively). There were no statistically significant causal associations observed between the five exposures and PD using either the IVW, weighted median, or MR-Egger methods (p-values of the IVW method: 0.332, 0.610, 0.634, 0.275, and 0.860, respectively). @*Conclusion@#This study does not support a clinically relevant causal effect of lipid levels, T2DM, and BMI on PD risk in a Korean population.

A case of successful surgical treatment for peritoneal seeding of hepatocellular carcinoma after radiotherapy and atezolizumab plus bevacizumab combination treatment

Peritoneal seeding of hepatocellular carcinoma (HCC) is incurable and has poor prognosis. A 68-year-old man underwent surgical resection for a 3.5 cm single nodular HCC at the tip of segment 3 and transarterial chemoembolization for a 1.5 cm-sized recurrent HCC at the tip of segment 6. 3 months later, an increasing 1 cm pelvic nodule on the rectovesical pouch warranted radiotherapy. Although it stabilized, a new 2.7 cm-sized peritoneal nodule in the right upper quadrant (RUQ) omentum appeared 3.5 years after radiotherapy. Hence, omental mass and small bowel mesentery mass excision were performed. 3 years later, recurrent peritoneal metastases in the RUQ omentum and rectovesical pouch progressed. 33 cycles of atezolizumab and bevacizumab treatment elicited stable disease response. Finally, laparoscopic left pelvic peritonectomy was performed without tumor recurrence. Herein, we present a case of HCC with peritoneal seeding that was successfully treated with surgery after radiotherapy and systemic therapy, leading to complete remission.

The Relationship Between Posttraumatic Embitterment Disorder and Stress, Depression, Self-Esteem, Impulsiveness, and Suicidal Ideation in Korea Soldiers in the Local Area

Background@#The purpose of this study was to identify the prevalence of posttraumatic embitterment disorder (PTED) among soldiers, and examine its relation to stress, depression, self-esteem, impulsiveness, and suicidal ideation. @*Methods@#The subjects of this study were 200 soldiers and 197 control subjects, a total of 397 persons. Measurement tools used included the PTED self-rating scale, Stress Response Inventory, Beck Depression Inventory, Rosenberg Self-Esteem Inventory, Barratt Impulsiveness Scale, and Beck Scale of Suicide Ideation.Result: The major findings of the analysis are as follows: first, 11.5% of the soldiers were in the risk group for PTED, and 4% of them had PTED. Second, PTED in the soldiers was significantly associated with a number of variables such as their educational background, stress, depression, self-esteem, impulsiveness, and suicidal ideation, while it was not significantly associated with age. Third, through the hierarchical multiple regression analysis, it was found that academic background, stress, and depression had a statistically significant positive effect on the incidence of PTED in the soldiers. @*Conclusion@#In order to prevent and effectively intervene in PTED in soldiers, there is a need for interventional efforts focused on depression and stress related to negative life events.

Short-Term Effectiveness of Oral Nirmatrelvir/Ritonavir Against the SARS-CoV-2 Omicron Variant and Culture-Positive Viral Shedding

Background@#Information on the effectiveness of nirmatrelvir/ritonavir against the omicron is limited. The clinical response and viral kinetics to therapy in the real world need to be evaluated. @*Methods@#Mild to moderate coronavirus disease 2019 (COVID-19) patients with risk factors for severe illness were prospectively enrolled as a treatment group with nirmatrelvir/ritonavir therapy versus a control group with supportive care. Serial viral load and culture from the upper respiratory tract were evaluated for seven days, and clinical responses and adverse reactions were evaluated for 28 days. @*Results@#A total of 51 patients were analyzed including 40 in the treatment group and 11 in the control group. Faster symptom resolution during hospitalization (P= 0.048) was observed in the treatment group. Only minor adverse reactions were reported in 27.5% of patients. The viral load on Day 7 was lower in the treatment group (P = 0.002). The viral culture showed a positivity of 67.6% (25/37) vs. 100% (6/6) on Day 1, 0% (0/37) vs. 16.7 (1/6) on Day 5, and 0% (0/16) vs. 50.0% (2/4) on Day 7 in the treatment and control groups, respectively. @*Conclusions@#Nirmatrelvir/ritonavir against the omicron was safe and resulted in negative viral culture conversion after Day 5 of treatment with better symptomatic resolution.

Different Pattern of T-Score Discordance between Patients with Atypical Femoral Fracture and Femur Neck Fracture

Background@#Our study evaluated the prevalence and pattern of T-score discordance between the spine and hip in Korean patients with atypical femoral fracture (AFF) and femur neck fracture (FNF). @*Methods@#A total of 49 patients (all women) who were treated for AFF and 1:3 matched 147 female patients with FNF were included from January 2012 to August 2022. A discordance of more than 1.5 between lumbar spine and femur neck bone mineral density (BMD) was defined as a difference and divided into 3 groups: lumbar low (LL; lumbar BMD is less than femur neck BMD), no discordance (ND), and femur neck low (FL; femur neck BMD is less than lumbar BMD). We compared the prevalence and pattern of discordance between 2 groups, and the associated risk factors of T-score discordance among the subjects were evaluated using regression analysis. @*Results@#The prevalence of discordance was significantly higher in patients with AFF (51%) than in those with FNF (25.2%; p<0.001). LL discordance was found in 46.9% of the patients with AFF but only 4.8% in those with FNF. Conversely, FL discordance was found in 4.1% of the patients with AFF and 20.4% in those with FNF, respectively. No specific risk factor was found as T-score discordance in the 2 groups. @*Conclusions@#Clinicians should be aware that the pattern of T-score discordance can vary depending on the location of osteoporotic fractures. In addition, a longitudinal study would be necessary to verify the pattern of T-score discordance related to the osteoporotic fracture location.

Preventive strategy for nonalcoholic fatty liver disease-related hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) associated with nonalcoholic fatty liver disease (NAFLD) has been increasing worldwide, including Asia. Most patients with NAFLD-related HCC are at a much-advanced stage and older age at the time of diagnosis than those with virus-related HCC because they have not undergone HCC surveillance. This review provides an overview of the mechanism of hepatocarcinogenesis in NAFLD, preventive strategies for NAFLDrelated HCC, and strategies for the surveillance of patients with NAFLD.

Real-World Study of Osimertinib in Korean Patients with Epidermal Growth Factor Receptor T790M Mutation–Positive Non–Small Cell Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Although osimertinib is the standard-of-care treatment of epidermal growth factor receptor (EGFR) T790M mutation–positive non–small cell lung cancer, real-world evidence on the efficacy of osimertinib is not enough to reflect the complexity of the entire course of treatment. Herein, we report on the use of osimertinib in patients with EGFR T790M mutation–positive non–small cell lung cancer who had previously received EGFR tyrosine kinase inhibitor (TKI) treatment in Korea. @*Materials and Methods@#Patients with confirmed EGFR T790M after disease progression of prior EGFR-TKI were enrolled and administered osimertinib 80 mg daily. The primary effectiveness outcome was progression-free survival, with time-to-treatment discontinuation, treatment and adverse effects leading to treatment discontinuation, and overall survival being the secondary endpoints. @*Results@#A total of 558 individuals were enrolled, and 55.2% had investigator-assessed responses. The median progression-free survival was 14.2 months (95% confidence interval [CI], 13.0 to 16.4), and the median time-to-treatment discontinuation was 15.0 months (95% CI, 14.1 to 15.9). The median overall survival was 36.7 months (95% CI, 30.9 to not reached). The benefit with osimertinib was consistent regardless of the age, sex, smoking history, and primary EGFR mutation subtype. However, hepatic metastases at the time of diagnosis, the presence of plasma EGFR T790M, and the shorter duration of prior EGFR-TKI treatment were poor predictors of osimertinib treatment. Ten patients (1.8%), including three with pneumonitis, had to discontinue osimertinib due to severe adverse effects. @*Conclusion@#Osimertinib demonstrated its clinical effectiveness and survival benefit for EGFR T790M mutation–positive in Korean patients with no new safety signals.

The Factors Affecting Longitudinal Course of Posttraumatic Stress Disorder Symptoms in Sexual Assault Victims

Objective@#This study aimed to identify the factors affecting posttraumatic stress disorder (PTSD) symptom remission prospectively through a 1-year follow-up of sexual assault (SA) victims. @*Methods@#A total 65 female SA victims who visited the crisis intervention center were included. Self-administered questionnaires regarding PTSD symptoms and PTSD related prognostic factors were conducted at both recruitment (T1) and 1 year after recruitment (T2). The multivariate analyses were used to determine the significant predictors of PTSD remissionon-remission state 1 year after SA. @*Results@#In logistic regression analysis, both anxiety and secondary victimization were identified as significant factors explaining the results on PTSD remissionon-remission state at T2 (Beck’s Anxiety Inventory [BAI], p=0.003; Secondary Victimization Questionnaire, p=0.024). In a linear mixed analysis, both depression and anxiety were found to be significant variables leading to changes in Posttraumatic Diagnostic Scale for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition from T1 to T2 (BAI, p<0.001; Center for Epidemiological Studies Depression Scale, p<0.001). @*Conclusion@#Depression, anxiety symptoms, and secondary victimization after SA were associated with PTSD symptom non-remission 1 year after SA.

SARS‑CoV‑2 Omicron variant causes brain infection with lymphoid depletion in a mouse COVID‑19 model / 한국실험동물학회지

Background@#The Omicron variant has become the most prevalent SARS-CoV-2 variant. Omicron is known to induce milder lesions compared to the original Wuhan strain. Fatal infection of the Wuhan strain into the brain has been well documented in COVID-19 mouse models and human COVID-19 cases, but apparent infections into the brain by Omicron have not been reported in human adult cases or animal models. In this study, we investigated whether Omicron could spread to the brain using K18-hACE2 mice susceptible to SARS-CoV-2 infection. @*Results@#K18-hACE2 mice were intranasally infected with 1 × 105 PFU of the original Wuhan strain and the Omicron variant of SARS-CoV-2. A follow-up was conducted 7 days post infection. All Wuhan-infected mice showed > 20% body weight loss, defined as the lethal condition, whereas two out of five Omicron-infected mice (40%) lost > 20% body weight. Histopathological analysis based on H&E staining revealed inflammatory responses in the brains of these two Omicron-infected mice. Immunostaining analysis of viral nucleocapsid protein revealed severe infection of neuron cells in the brains of these two Omicron-infected mice. Lymphoid depletion and apoptosis were observed in the spleen of Omicron-infected mice with brain infection. @*Conclusion@#Lethal conditions, such as severe body weight loss and encephalopathy, can occur in Omicron-infected K18-hACE2 mice. Our study reports, for the first time, that Omicron can induce brain infection with lymphoid depletion in the mouse COVID-19 model.

Small intestinal epiploic foramen entrapment in a seven-month pregnant Thoroughbred mare: a case report

A seven-month pregnant four-year-old Thoroughbred mare with colic weighing 600 kg was referred to the Jeju National University Equine Hospital. A physical examination and ultrasound suggested epiploic foramen entrapment. The patient underwent ileum resection and end-to-side jejunocecostomy. After surgery, the horse showed a consistent pain when introduced to feeding. A repeat laparotomy was performed to enlarge the stoma size with side-to-side jejunocecostomy. The repeat laparotomy was successful, and the mare gave birth uneventfully. This report describes a case of small intestinal epiploic foramen entrapment and the clinical outcomes of the 2 consecutive laparotomies a Thoroughbred mare in late gestation.

Infectious diseases and biomarker use

Biomarkers are used in diverse clinical fields, including oncological, cardiovascular, infectious, and rheumatoid diseases. In infectious diseases, biomarkers are widely used for identifying fever due to infection, evaluating the possibility of progression to sepsis, predicting prognosis, estimating treatment response, and determining the timing of discontinuation of antibiotic treatment. Thus, biomarkers are used as indicators that can inform clinical decisions.Current Concepts: Biomarkers for infectious diseases typically relate to inflammatory processes in, which are activated by external antigens. Historically, research has focused on acute phase reactants; however, more recently, various inflammatory response biomarkers have been investigated.Discussion and Conclusion: To date, no infallible biomarker has been identified for infectious diseases. The main reasons are the potential for these molecules to also be affected by non-infectious causes and the individual differences in the degree of change of the biomarker. Although diagnosis and clinical decisions cannot depend on biomarkers alone, these are undoubtedly essential tools in clinical contexts, if thoroughly and carefully characterized. Here, we review several substances used or showing significant potential as biomarkers for infectious diseases.