Prediction of Postoperative Lung Function in Lung Cancer Patients Using Machine Learning Models / 결핵및호흡기질환

Background@#Surgical resection is the standard treatment for early-stage lung cancer. Since postoperative lung function is related to mortality, predicted postoperative lung function is used to determine the treatment modality. The aim of this study was to evaluate the predictive performance of linear regression and machine learning models. @*Methods@#We extracted data from the Clinical Data Warehouse and developed three sets: set I, the linear regression model; set II, machine learning models omitting the missing data: and set III, machine learning models imputing the missing data. Six machine learning models, the least absolute shrinkage and selection operator (LASSO), Ridge regression, ElasticNet, Random Forest, eXtreme gradient boosting (XGBoost), and the light gradient boosting machine (LightGBM) were implemented. The forced expiratory volume in 1 second measured 6 months after surgery was defined as the outcome. Five-fold cross-validation was performed for hyperparameter tuning of the machine learning models. The dataset was split into training and test datasets at a 70:30 ratio. Implementation was done after dataset splitting in set III. Predictive performance was evaluated by R2 and mean squared error (MSE) in the three sets. @*Results@#A total of 1,487 patients were included in sets I and III and 896 patients were included in set II. In set I, the R2 value was 0.27 and in set II, LightGBM was the best model with the highest R2 value of 0.5 and the lowest MSE of 154.95. In set III, LightGBM was the best model with the highest R2 value of 0.56 and the lowest MSE of 174.07. @*Conclusion@#The LightGBM model showed the best performance in predicting postoperative lung function.

Attachment Insecurity and Stigma as Predictors of Depression and Anxiety in People Living With HIV

Objective@#The purpose of this study was to examine whether attachment insecurity, stigma, and certain demographic and medical factors predict depression and anxiety in people living with HIV (PLWH). @*Methods@#Participants were 147 PLWH who visited the outpatient infection clinic in Kyungpook National University Hospital (KNUH; Daegu, South Korea) between June 2020 and January 2021. We measured HIV-related stigma, attachment anxiety and avoidance, depressive symptoms, and anxiety symptoms. @*Results@#Logistic regression analysis showed that unemployment, longer time receiving antiretroviral therapy, higher attachment avoidance, and higher attachment anxiety were significant predictors of depression. Results also showed that longer time receiving antiretroviral therapy, higher attachment anxiety, and concern with public attitudes were significant predictors of anxiety. @*Conclusion@#In addition to education to reduce public stigma, interventions to reduce PLWH’s self-stigma should continue. We suggest attachment-based psychotherapy as an effective intervention to improve PLWH’s mental health.

Inhibition of angiotensin converting enzyme increases PKCβI isoform expression via activation of substance P and bradykinin receptors in cultured astrocytes of mice

Background@#Angiotensin-converting enzyme inhibitor (ACEi) inhibits the catalysis of angiotensin I to angiotensin II and the degradation of substance P (SP) and bradykinin (BK). While the possible relationship between ACEi and SP in nociceptive mice was recently suggested, the effect of ACEi on signal transduction in astrocytes remains unclear. @*Objectives@#This study examined whether ACE inhibition with captopril or enalapril modulates the levels of SP and BK in primary cultured astrocytes and whether this change modulates PKC isoforms (PKCα, PKCβI, and PKCε) expression in cultured astrocytes. @*Methods@#Immunocytochemistry and Western blot analysis were performed to examine the changes in the levels of SP and BK and the expression of the PKC isoforms in primary cultured astrocytes, respectively. @*Results@#The treatment of captopril or enalapril increased the immunoreactivity of SP and BK significantly in glial fibrillary acidic protein-positive cultured astrocytes. These increases were suppressed by a pretreatment with an angiotensin-converting enzyme.In addition, treatment with captopril increased the expression of the PKCβI isoform in cultured astrocytes, while there were no changes in the expression of the PKCα and PKCε isoforms after the captopril treatment. The captopril-induced increased expression of the PKCβI isoform was inhibited by a pretreatment with the neurokinin-1 receptor antagonist, L-733,060, the BK B 1 receptor antagonist, R 715, or the BK B 2 receptor antagonist, HOE 140. @*Conclusions@#These results suggest that ACE inhibition with captopril or enalapril increases the levels of SP and BK in cultured astrocytes and that the activation of SP and BK receptors mediates the captopril-induced increase in the expression of the PKCβI isoform.

Long-term Clinical Course and Prognostic Factor of Branch Retinal Artery Occlusion

Purpose@#To investigate the long-term clinical course and prognostic factors of branch retinal artery occlusion (BRAO). @*Methods@#The medical records of patients diagnosed with BRAO were reviewed retrospectively. Visual acuity (VA) and central retinal thickness (CRT) at diagnosis were compared with those measured at the final visit. Patients with a decimal VA ≥ 0.6 (good prognosis group) were compared with those with a decimal VA ≤ 0.5 (poor prognosis group) at the final visit. @*Results@#Fifty-five patients were enrolled and the mean follow-up period was 45.8 ± 27.8 months. The mean logarithm of minimum angle of resolution improved from 0.53 ± 0.57 at diagnosis to 0.36 ± 0.61 at the final visit (p = 0.026). The decimal VA was ≤ 0.1 in 13 (23.6%) patients, ≥ 0.2 and ≤ 0.5 in 16 (29.1%) patients, and ≥ 0.6 in 26 (47.3%) patients at diagnosis; the respective values were 9 (16.4%), 8 (14.5%), and 38 (69.1%) at the final visit. The mean CRT significantly decreased from 273.9 ± 34.7 µm at diagnosis to 248.9 ± 27.0 µm at the final visit (p < 0.001). The poor prognosis group (n = 17) was older (p = 0.044) and had a higher incidence of papillomacular bundle involvement (p < 0.001) than the good prognosis group (n = 38). @*Conclusions@#Patients with BRAO generally showed relatively favorable long-term outcomes. However, the final VA was ≤ 0.1 in 16.4% of them, suggesting the need for further treatment modalities to improve the outcome of patients with a poor prognosis.

Course of Neovascular Age-related Macular Degeneration that Showed Limited Response to Both Ranibizumab and Aflibercept

Purpose@#To evaluate the clinical course of neovascular age-related macular degeneration (nAMD) that has shown limited response to ranibizumab and aflibercept. @*Methods@#This retrospective study included 14 eyes with nAMD that showed a limited response to initial treatment using ranibizumab and aflibercept. The changes in visual acuity (VA) during the follow-up period and the incidence and timing of VA deterioration to the level of 0.1 or worse were identified. In cases involving bevacizumab treatment, the follow-up duration and the proportion of patients maintaining a VA of 0.2 or better were identified. @*Results@#During the mean 43.3 ± 33.2 months of follow-up, the VA deteriorated significantly from a mean logarithm of minimum angle of resolution (logMAR) of 0.42 ± 0.34 at diagnosis to 0.91 ± 0.68 at the final follow-up (p = 0.021). A logMAR of 0.3 or greater degree of VA deterioration was noted in six eyes (42.9%). Among the 13 eyes exhibiting a VA of 0.2 or better after the initial treatment, a deterioration to a VA of 0.1 or worse was noted in 6 eyes (46.2%) at a mean 29.7 ± 18.3 months. In eight eyes undergoing bevacizumab treatment, four eyes (50.0%) maintained 0.2 or better VA during the 51.4 ± 35.5 months of follow-up. @*Conclusions@#The clinical course of patients with limited response to ranibizumab and aflibercept was generally unfavorable. However, a relatively long period was required for the deterioration in VA to reach 0.1 or worse. In addition, 0.2 or better VA was maintained in approximately half of the patients.

Use of antiseizure medications after traumatic brain injury

Post-traumatic seizures and epilepsy are major complications that increase the mortality rate among patients with traumatic brain injury (TBI) and hinder functional recovery. It is important to establish prophylaxis and treatment strategies for high-risk patients. The use of antiseizure medications may not only adversely affect the cognitive function following TBI but also may be associated with a worse rehabilitation outcome.Current Concepts: The level of evidence in the current international guidelines related to the prophylaxis and management of post-traumatic seizure is not robust. Furthermore, the use of antiseizure medications after TBI remains unclear, indicating substantial variations in clinical practice.Discussion and Conclusion: Prophylactic antiseizure medications can reduce the risk of early seizures and partially prevent the secondary injury process of TBI; however, they do not seem to inhibit epileptogenesis. Therefore, if the benefits of preventing early seizures outweigh the potential risks associated with antiseizure medication, it is recommended to use them for a short period of about one week after the injury. Then, it is not recommended to continue using them routinely without considering the individual risk of seizure recurrence and potential adverse effects of long-term use. The treatment duration of anticonvulsant in patients with post-traumatic epilepsy should also be determined based on the individual risk of seizure recurrence, and the decision should take into account the opinions of both the patient and the caregiver, while considering not only the potential benefits but also the risks associated with long-term use.

Decrease of Muscle Mass in Young Patients With Neuromuscular Disease:Assessment of Sarcopenia

Background@#Sarcopenia can be associated with the disease etiologies other than degenerative processes, such as neurologic disease including cerebral palsy, myelomeningocele, or Duchenne muscular dystrophy, even in children. Although the relationship between neurologic disease and scoliosis or ambulatory function is known, the mediators affecting scoliosis or gait function in these patients are unclear, an example might be sarcopenia. This study aimed to assess the degree of sarcopenia in young patients with neurologic diseases using computed tomography (CT), and analyze the correlation between sarcopenia and scoliosis or ambulatory function. @*Methods@#Pediatric and young adult patients (≤ 25 years old) who underwent whole-spine or lower-extremity CT were retrospectively included. From bilateral psoas muscle areas (PMAs) at the L3 level, the psoas muscle z-score (PMz) and psoas muscle index [PMI = PMA/(L3 height) 2 ] were calculated. The t-test, Fisher’s exact test, and logistic regression analyses were performed. @*Results@#A total of 121 patients (56 men, mean age 12.2 ± 3.7 years) were included with 79 neurologic and 42 non-neurologic diseases. Patients with neurologic diseases had lower PMz (P = 0.013) and PMI (P = 0.026) than patients without. In neurologic disease patients, severe scoliosis patients showed lower PMz (P < 0.001) and PMI (P = 0.001). Non-ambulatory patients (n = 42) showed lower BMI (β = 0.727, P < 0.001) and PMz (β = 0.547, P = 0.025). In non-ambulatory patients, patients with severe scoliosis also showed lower PMz (P < 0.001) and PMI (P = 0.004). @*Conclusion@#Patients with neurologic diseases could have sarcopenia even in young age.Psoas muscle volume was also associated with ambulatory function in these patients.Sarcopenia was more severe in severe scoliosis patients in the non-ambulatory subgroup.

Effect of Total Hip Arthroplasty on Ipsilateral Lower Limb Alignment and Knee Joint Space Width: Minimum 5-Year Follow-up

Background@#This study aimed to 1) assess the effect of total hip arthroplasty (THA) on coronal limb alignment, namely, the hip–knee–ankle angle (HKA), 2) identify factors that determine changes in the HKA, and 3) determine whether alignment changes influence the knee joint space width. @*Methods@#We retrospectively evaluated 266 limbs of patients who underwent THA. Three types of prostheses with neck shaft angles (NSAs) of 132°, 135°, and 138° were used. Several radiographic parameters were measured in the preoperative and final radiographs (at least 5 years after THA). A paired t-test was used to confirm the effect of THA on HKA change.Multiple regression analysis was performed to identify radiographic parameters related to HKA changes following THA and changes in knee joint space width. Subgroup analyses were performed to reveal the effect of NSA change on the HKA change, and the proportion of total knee arthroplasty usage and changes in radiographic parameters between maintained joint space and narrowed joint space groups were compared. @*Results@#The preoperative mean HKA was 1.4° varus and increased to 2.7° varus after THA.This change was related to changes in the NSA, lateral distal femoral angle, and femoral bowing angle. In particular, in the group with a decrease in NSA of > 5°, the preoperative mean HKA was largely changed from 1.4° varus to 4.6° varus after THA. The prostheses with NSA of 132° and 135° also led to greater varus HKA changes than those with an NSA of 138°. Narrowing of the medial knee joint space was related to changes in the varus direction of the HKA, decrease in NSA, increase in femoral offset. @*Conclusion@#A large reduction in NSA can lead to considerable varus limb alignment after THA, which can have adverse effects on the medial compartment of the ipsilateral knee.

Concomitant ankylosing spondylitis can increase the risk of biologics or small molecule therapies to control inflammatory bowel disease

Background/Aims@#Patients with inflammatory bowel disease (IBD) are diagnosed with ankylosing spondylitis (AS) often. However, the disease course of patients with both IBD and AS is not well understood. This study aims to evaluate the effect of concomitant AS on IBD outcomes. @*Methods@#Among the 4,722 patients with IBD who were treated in 3 academic hospitals from 2004 to 2021, 55 were also diagnosed with AS (IBD-AS group). Based on patients’ electronic medical records, the outcomes of IBD in IBD-AS group and IBD group without AS (IBD-only group) were appraised. @*Results@#The proportion of patients treated with biologics or small molecule therapies was significantly higher in IBD-AS group than the proportion in IBD-only group (27.3% vs. 12.7%, P= 0.036). Patients with both ulcerative colitis and AS had a significantly higher risk of biologics or small molecule therapies than patients with only ulcerative colitis (P< 0.001). For univariable logistic regression, biologics or small molecule therapies were associated with concomitant AS (odds ratio, 4.099; 95% confidence interval, 1.863–9.021; P< 0.001) and Crohn’s disease (odds ratio, 3.552; 95% confidence interval, 1.590–7.934; P= 0.002). @*Conclusions@#Concomitant AS is associated with the high possibility of biologics or small molecule therapies for IBD. IBD patients who also had AS may need more careful examination and active treatment to alleviate the severity of IBD.

Comparison of Midline Splitting versus Unilateral Open Door Laminoplasty and Its Impact on Patient Outcomes

Background@#Laminoplasty is a common and effective surgery for decompression of the spinal cord in multilevel cervical myelopathy. The midline splitting technique (MST) and the unilateral open door technique (UODT) are the two most commonly performed laminoplasty techniques with continuous debate on which is preferable. This study aimed to add light to the matter by comparing and exploring the possible causes of different outcomes. @*Methods@#A total of 101 patients who underwent laminoplasty for degenerative cervical myelopathy were included in this study.Radiographic measurements including C2–7 Cobb angle, C2–7 range of motion (ROM), Pavlov ratio of the most compressed level, and canal area with diameter were compared. Modified Japanese Orthopedic Association (mJOA) score and complications including C5 palsy, axial neck pain, hinge fractures, and spacer displacement were also compared. Statistical analysis was performed using independent samples t-test, chi-square test, Fisher’s exact test, and linear mixed model. @*Results@#C2–7 ROM, canal diameter, Pavlov ratio, and mJOA score did not demonstrate differences between the two techniques.The UODT group had greater postoperative canal expansion but had more loss of C2–7 lordosis than did the MST group. Of the complications, hinge fractures were more common in the UODT group, with more loss of C2–7 lordosis in patients with hinge fractures. On the other hand, spacer displacement occurred only in the MST group, with lesser canal expansion in patients with spacer displacement. @*Conclusions@#The two laminoplasty techniques both demonstrated effectiveness in treating patients with multilevel cervical myelopathy. However, care should be given to avoid hinge fractures and spacer displacement since both can possibly lead to unfavorable outcomes.

Primary Cutaneous Apocrine Carcinoma and Syringocystadenoma Papilliferum Arising in Nevus Sebaceus: A Case Report and Review of the Literature

Nevus sebaceus is a hamartomatous lesion characterized by epidermal, follicular, sebaceus, and apocrine gland abnormalities. Approximately 25% of affected individuals may develop benign or malignant secondary neoplasms within the preceding nevus sebaceus. Primary cutaneous apocrine carcinoma (PCAC) is a rare malignant skin tumor affecting elderly adults in their sixth decade of life. Histologically, PCAC appears as a dermal tumor displaying apocrine differentiation with decapitation secretion and malignant features. Secondary malignancy arising from nevus sebaceus is a rare complication, especially for apocrine carcinoma. To date, approximately 200 cases of PCAC have been reported in the literature, and only a few cases have developed PCAC on the scalp. Very few cases (approximately only 12) of PCACs developing in nevus sebaceus have been reported. Here, we report an extremely rare case of the coexistence of PCAC and syringocystadenoma papilliferum arising within nevus sebaceus of the scalp.

Hereditary Leiomyomatosis and Renal Cell Cancer: A Case Report of Pilar Leiomyomatosis with History of Kidney Cancer and Review of the Literature

Pilar leiomyoma or piloleiomyoma is a benign neoplasm of the smooth muscle arising from the arrector pili muscle. It manifests as brown to red firm papulonodules with sites of predilection being the face, trunk, and extensor surfaces of the extremities. Histologically, the lesions exhibit ill-defined dermal tumors with interlacing fascicles of spindle cells. Some genodermatoses are characterized by the development of visceral tumors and cutaneous leiomyomatosis such as Reed’s syndrome, and hereditary leiomyomatosis and renal cell cancer (HLRCC). A 55-year-old male presented with reddish-brown papules and nodules on the face and upper back, accompanied by sharp episodic pain on the face. He had undergone nephrectomy for renal cancer 9 years ago, and his younger brother had similar cutaneous manifestation. Histopathologic findings were consistent with pilar leiomyoma, showing bundles of smooth muscle tumors in the dermis. Based on the clinical information including clinical features, past medical history, and family history, HLRCC was highly suspected.To confirm the diagnosis, whole exome sequencing was performed using peripheral blood, which revealed a novel point mutation (c.739G>A, p.Glu247Lys) in the fumarate hydratase (FH) gene. We describe a confirmed case of HLRCC, which is a genetic disorder with a potential to cause visceral cancers, which dermatologists might overlook as a benign condition.

A Case Report of Rubinstein-Taybi Syndrome Presenting with Extensive Keloid Formation and Review of Literature

Rubinstein-Taybi syndrome (RSTS) is an extremely rare genetic disorder affecting multi-organ systems. A tendency to form keloid is one of the common dermatologic manifestations.We describe a 23-year-old female presented with extensive keloids which developed spontaneously. She had typical facial features, broad thumbs, and dental defects, which were suspicious features of genetic syndrome. Direct sequencing for cyclic-AMP-regulated enhancer binding protein revealed a novel mutation. So far, 23 cases of RSTS have been reported in Korean literature. To the best of our knowledge, this is the first report in Korea to describe confirmed case of RSTS with extensive keloids as a chief manifestation.

Application of competency-based education in the Korean anesthesiology residency program and survey analysis / 대한마취과학회지

Background@#Although competency-based education (CBE) is becoming a popular form of medical education, it has not been used to train residents. Recently, the Korean Society of Anesthesiologists completed a pilot implementation and evaluation of a CBE program.This study aims to outline the experience. @*Methods@#The chief training faculty from each hospital took a one-hour online course about CBE. Emails on the seven core competencies and their evaluation were sent ahead of a pilot core competency evaluation (CCE) to residents and faculty. The pilot CCE took place in late 2021, followed by a survey. @*Results@#A total of 68 out of 84 hospitals participated in the pilot CCE. The survey response rate was 55.9% (38/68) for chief training faculty, 10.2% (91/888) for training faculty, and 30.2% (206/683) for residents. More than half of the training faculty thought that CCE was necessary for the education of residents. Residents’ and training faculty’s responses about CCE were generally positive, although their understanding of CCE criteria was low. More than 80% of the hospitals had a defibrillator and cardiopulmonary resuscitation manikin while the rarest piece of equipment was an ultrasound vessel model. Only defibrillators were used in more than half of the hospitals. Thoughts about CCE were related to various factors, such as length of employment, location of hospitals, and the number of residents per grade. @*Conclusions@#This study’s results may be helpful in improving resident education quality to meet the expectations of both teaching faculty and residents while establishing CBE.

Clinical features of anaphylaxis and risk factors of severe anaphylaxis in the emergency department

Objective@#This study investigates the triggers and clinical features of anaphylaxis, and determines the risk factors associated with severe anaphylaxis. @*Methods@#This is a retrospective observational study spanning a duration of 2 years (2020-2021) using the electronic data of patients diagnosed with anaphylaxis in the university-affiliated emergency center. Severe anaphylaxis was defined as refractory anaphylaxis requiring ≥3 times epinephrine administration and/or continuous epinephrine infusion. Baseline and clinical characteristics were compared between the severe and the non-severe anaphylaxis groups. Binary logistic regression analysis was performed to reveal independent risk factors associated with severe anaphylaxis. @*Results@#The median age of study patients was determined to be 53.0 years (range, 37.5-65.0 years). Fifty-eight patients (58.0%) were male. Drugs were found to be the most common trigger. In clinical manifestations, cutaneous manifestation was the most common. Severe anaphylaxis occurred in 19 patients (19.0%). Latent time was shorter in the severe anaphylaxis group-10.0 minutes (5.0-20.0) vs. 30.0 minutes (10.0-60.0), P<0.001. Drug as a trigger (68.4% vs. 39.5%, P=0.023), hypotension (57.9% vs. 9.9%, P<0.001), cardiovascular manifestation (84.2% vs. 40.7%, P=0.001), and hyperlactatemia (73.7% vs. 46.9%, P=0.036) were more frequently observed in the severe anaphylaxis group. Shorter latent time, drug as a trigger, and presence of hypotension were independent risk factors for severe anaphylaxis. @*Conclusion@#Anaphylaxis patients with shorter latent time, diagnosed with drugs as a trigger, and presenting with hypotension, must be subjected to careful monitoring and early active treatment.

Effect of Homocysteine on the Expression of Matrix Metalloproteinase-9 and Apoptosis in Trabecular Meshwork Cells

Purpose@#In retinal endothelial cells, homocysteine (Hcy) activates matrix metalloproteinase (MMP)-9, which results in apoptosis. This study investigated these effects of Hcy in human trabecular meshwork cells (HTMC). @*Methods@#HTMC cultures using 5 mM low or 20 mM high glucose (HG)-containing media were exposed to 100 μM Hcy for 3 days. Cell viability was assessed with the MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay. The MMP-9 and tissue inhibitor of MMP (TIMP)-1 levels were measured by western blotting and the degree of apoptosis was analyzed with flow cytometry using Annexin-propidium iodide double staining. @*Results@#Exposure to Hcy in HG decreased cell viability compared to HG alone (p = 0.036). Compared to HG alone, co-exposure to Hcy with HG decreased the TIMP-1 levels, albeit not significantly (p = 0.094), and did not affect the MMP-9 levels (p = 0.413). In addition, co-exposure to Hcy with HG produced no difference in the degree of apoptosis compared to HG alone (p = 0.437). @*Conclusions@#Unlike in retinal endothelial cells, Hcy did not affect the activities of TIMP-1, MMP-9, or the degrees of apoptosis significantly in HTMC. Thus, the effects Hcy may be limited in HTMC.

Use of Antibiotics Within the Last 14 Days of Life in Korean Patients:A Nationwide Study

Background@#Antimicrobial prescriptions for serious chronic or acute illness nearing its end stages raise concerns about the potential for futile use, adverse events, increased multidrugresistant organisms, and significant patient and social cost burdens. This study investigated the nationwide situation of how antibiotics are prescribed to patients during the last 14 days of life to guide future actions. @*Methods@#This nationwide multicenter retrospective cohort study was conducted at 13 hospitals in South Korea from November 1 to December 31, 2018. All decedents were included in the study. Antibiotic use during the last two weeks of their lives was investigated. @*Results@#A total of 1,201 (88.9%) patients received a median of two antimicrobial agents during the last two weeks of their lives. Carbapenems were prescribed to approximately half of the patients (44.4%) in the highest amount (301.2 days of therapy per 1,000 patient-days).Among the patients receiving antimicrobial agents, 63.6% were inappropriate and only 327 patients (27.2%) were referred by infectious disease specialists. The use of carbapenem (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.13–2.03; P = 0.006), underlying cancer (OR, 1.56; 95% CI, 1.20–2.01, P = 0.047), underlying cerebrovascular disease (OR, 1.88; 95% CI, 1.23–2.89, P = 0.004), and no microbiological testing (OR, 1.79; 95% CI, 1.15–2.73; P = 0.010) were independent predictors for inappropriate antibiotic prescribing. @*Conclusion@#A considerable number of antimicrobial agents are administered to patients with chronic or acute illnesses nearing their end-of-life, a high proportion of which are prescribed inappropriately. Consultation with an infectious disease specialist, in addition to an antimicrobial stewardship program, may be necessary to induce the optimal use of antibiotics.

Development and Application of a Cell-Based Assay for LRP4 Antibody Associated With Myasthenia Gravis

Background@#and Purpose Among patients with double-seronegative myasthenia gravis (dSN-MG) who do not have detectable antibodies against acetylcholine receptor or musclespecific tyrosine kinase, autoantibodies against low-density lipoprotein receptor-related protein 4 (LRP4-Ab) have been detected recently. The purpose of this study was to develop an in-house cell-based assay (CBA) to detect LRP4-Ab and to apply it to samples from patients with MG. @*Methods@#The complementary DNA of LRP4 fused into a vector plasmid containing GFP was transfected into human embryonic kidney 293 (HEK293) cells. LRP4 expression in the transfected HEK293 cells was assessed using the reverse-transcription polymerase chain reaction (RT-PCR), Western blotting, and immunocytochemistry. The CBA included 252 sera collected from 202 patients with MG and 38 with other neuromuscular diseases, and 12 healthy controls. The transfected HEK293 cells were incubated using sera and antihuman immunoglobulin G antibodies conjugated with Alexa Fluor 594. The presence of LRP4-Ab was determined based on the fluorescence intensity and the localization in fluorescence microscopy. @*Results@#The expressions of the mRNA and protein of LRP4 in the transfected HEK293 cells were confirmed using RT-PCR and Western blotting, respectively. Immunocytochemistry indicated LPR4 expression on the cell membrane. Among 202 patients with MG including 53 with dSN-MG, LRP4-Ab were positive in 3 patients who were all double seronegative. LRP4-Ab were not detected in the patients with other neuromuscular diseases or the healthy controls. @*Conclusions@#A CBA for detecting LRP4-Ab associated with MG has been developed, and was used to find LRP4-Ab in the sera of patients with MG.

Fracture Liaison Service in Korea: 2022 Position Statement of the Korean Society for Bone and Mineral Research

Osteoporosis and osteoporotic fractures cause socioeconomic concerns, and medical system and policies appear insufficient to prepare for these issues in Korea, where the older adult population is rapidly increasing. Many countries around the world are already responding to osteoporosis and osteoporotic fractures by adopting fracture liaison service (FLS), and such an attempt has only begun in Korea. In this article, we introduce the operation methods for institutions implementing FLS and characteristics of services, and activities of the FLS Committee for FLS implementation in the Korean Society for Bone and Mineral Research. In addition, we hope that the current position statement will contribute to the implementation of FLS in Korea and impel policy changes to enable a multidisciplinary and integrated FLS operated under the medical system.

No Difference in Clinical Outcomes and Survivorship for Robotic, Navigational, and Conventional Primary Total Knee Arthroplasty with a Minimum Follow-up of 10 Years

Background@#Computer-assisted surgery, including robotic and navigational total knee arthroplasty (TKA), has been proposed as a technique used to improve alignment of implants. The purpose of this study was to compare the clinical and radiological outcomes during a minimum follow-up period of 10 years among robotic, navigational, and conventional TKA. @*Methods@#A total of 855 knees (robotic group, 194; conventional group, 270; and navigational group, 391) were available for physical and radiological examinations over a mean follow-up period of 10 years. The survival rate was analyzed using the KaplanMeier method based on the survival endpoint. The Hospital for Special Surgery score, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society Score, and range of motion were used for clinical evaluation. The hip-knee-ankle (HKA) axis angle, the coronal inclination of femoral and tibial components, and the presence of radiolucent lines were also assessed at the final follow-up. @*Results@#All clinical assessments at the final follow-up revealed improvements in the three groups without any significant difference among the groups (p> 0.05). The cumulative 10-year survival rate was 97.4% in the robotic group, 96.6% in the conventional group, and 98.2% in the navigational group, with no significant difference (p = 0.447). The rates of complication-associated surgery were not significantly different among the groups (p = 0.907). Only the proportion of outliers in the HKA axis angle showed a significant difference (p = 0.001), but other radiological outcomes were not significantly different among the three groups. @*Conclusions@#Our study demonstrated satisfactory survival rates for robotic, navigational, and conventional TKAs and similar clinical outcomes during the long-term follow-up. Larger studies with continuous serial data are needed to confirm these findings.