The Immobilization of an FGF2-Derived Peptide on Culture Plates Improves the Production and Therapeutic Potential of Extracellular Vesicles from Wharton's Jelly Mesenchymal Stem Cells.

The skin is an essential organ that protects the body from external aggressions; therefore, damage from various wounds can significantly impair its function, and effective methods for regenerating and restoring its barrier function are crucial. This study aimed to mass-produce wound-healing exosomes using a fragment of the fibroblast growth factor 2 (FGF2)-derived peptide (FP2) to enhance cell proliferation and exosome production. Our experiments demonstrated increased cell proliferation when Wharton's jelly mesenchymal stem cells (WJ MSCs) were coated with FP2. Exosomes from FP2-coated WJ MSCs were analyzed using nanoparticle-tracking analysis, transmission electron microscopy, and Western blotting. Subsequently, fibroblasts were treated with these exosomes, and their viability and migration effects were compared. Anti-inflammatory effects were also evaluated by inducing pro-inflammatory factors in RAW264.7 cells. The treatment of fibroblasts with FP2-coated WJ MSC-derived exosomes (FP2-exo) increased the expression of FGF2, confirming their wound-healing effect in vivo. Overall, the results of this study highlight the significant impact of FP2 on the proliferation of WJ MSCs and the anti-inflammatory and wound-healing effects of exosomes, suggesting potential applications beyond wound healing.

Expandable Cages for Lumbar Interbody Fusion: A Narrative Review.

Lumbar fusion surgery for treating degenerative spinal diseases has undergone significant advancements in recent years. In addition to posterior instrumentation, anterior interbody fusion techniques have been developed along with various cages for interbody fusion. Recently, expandable cages capable of altering height, lordotic angle, and footprint within the disc space have garnered significant attention. In this manuscript, we review the current status, clinical outcomes, and future prospects of expandable cages for lumbar interbody fusion based on the existing literature. Expandable cages are suitable for minimally invasive spinal surgeries. Small-sized cages can be inserted and subsequently expanded to a larger size within the disc space. While expandable cages generally demonstrate superior clinical outcomes compared to static cages, some studies have suggested comparable or even poorer outcomes with expandable cages than static cages. Careful interpretation through additional long-term follow-ups is required to assess the utility of expandable cages. If these shortcomings are addressed and the advantages are further developed, expandable cages could become suitable surgical instruments for minimally invasive spinal surgeries.

Pre-mixing of omega-3 fatty acid-containing liposomes enhances the drug release rate and therapeutic efficacy of anticancer drugs loaded in liposomes.

The therapeutic efficacy of anticancer drugs loaded in liposomes composed of rigid phosphatidylcholine (PC) is hindered by the limited release of these drugs at the tumor site, which in turn hampers delivery of the drug to its intracellular target. In an attempt to improve the therapeutic efficacy of liposomal anticancer drugs, we here explored the use of empty liposomes as "trigger" vehicles to induce drug release from drug-loaded liposomes through liposome-liposome interactions. Empty liposomes containing PC in which omega-3 fatty acids comprised both fatty acid strands (Omega-L) showed a triggering effect on drug release from doxorubicin (DOX)-loaded liposomes (Caelyx). The effectiveness of this triggered-release effect was dependent on the Omega-L composition as well as the mixing ratio of Omega-L to Caelyx. Cryo-TEM and differential calorimetry studies revealed that the Omega-L effect was associated with liposome-liposome interactions that led to loosened membrane packing and increased fluidity of Caelyx. In cultured cells, the intracellular/intranuclear DOX uptake and anticancer efficacy of Caelyx was greatly improved by Omega-L pre-mixing. Intravenous injection of rats with Caelyx, premixed with Omega-L, decreased the area under the plasma concentration-time curve from time zero to time infinity and increased clearance without significantly changing the mean residence time or terminal half-life of DOX compared with Caelyx alone. Ex vivo bioimaging showed that DOX fluorescence in tumors, but not in other organs, was significantly increased by Omega-L premixing. In the mouse xenograft model, premixing of Omega-L with Caelyx suppressed tumor growth 2.5-fold compared with Caelyx. Collectively, the data provide preliminary evidence that the Omega-L-triggered drug release that occurs before and after dosing, particularly at tumor site, improved the therapeutic efficacy of Caelyx. The simple approach described here could enhance the therapeutic value of Caelyx and other anticancer drug-loaded liposomes.

Renal histopathological predictors of end-stage kidney disease in ANCA-associated vasculitis with glomerulonephritis: a single-centre study in Korea.

This study investigated whether histopathological classification and histologic lesion scores could significantly and independently predict the progression to end-stage kidney disease (ESKD) in Korean patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis-glomerulonephritis (AAV-GN). This study included 113 patients with AAV-GN confirmed by kidney biopsy. The glomerular, tubulointerstitial, and vascular lesions were systematically assessed using a scoring system. The scoring system was adopted from the Banff scoring system but also the Oxford study and the revision of the ISN/RPS. For comparison, the scores were classified into two groups; the low, and the high, and the difference was investigated between ESKD and non-ESKD groups using Cox proportional analysis. At diagnosis, the median age was 59.0 years and 33.6% were males. Of 113 patients, 44.2% had ESKD progression during follow-up. There were significant differences in several kidney-, inflammation-, and AAV-pathogenesis-related variables between AAV-GN patients with ESKD and those without. The sclerotic class exhibited the worst renal prognosis among the four histopathological classes. Among histopathological features, high interstitial fibrosis, tubular atrophy and global glomerulitis scores were significantly associated with ESKD progression. Whereas multivariable Cox analysis revealed only a high global glomerulitis score which means global endocapillary hypercellularity in a larger number of glomeruli is an independent predictor of ESKD progression. Moreover, among clinical and histopathological features, a high global glomerulitis score could also predict ESKD progression in addition to serum blood urea nitrogen and creatinine. This study demonstrated the worst renal prognosis for the sclerotic class and first discovered that a high global glomerulitis score was an independent predictor of ESKD in patients with AAV-GN.

Bioactive peptides for boosting stem cell culture platform: Methods and applications.

Peptides, short protein fragments, can emulate the functions of their full-length native counterparts. Peptides are considered potent recombinant protein alternatives due to their specificity, high stability, low production cost, and ability to be easily tailored and immobilized. Stem cell proliferation and differentiation processes are orchestrated by an intricate interaction between numerous growth factors and proteins and their target receptors and ligands. Various growth factors, functional proteins, and cellular matrix-derived peptides efficiently enhance stem cell adhesion, proliferation, and directed differentiation. For that, peptides can be immobilized on a culture plate or conjugated to scaffolds, such as hydrogels or synthetic matrices. In this review, we assess the applications of a variety of peptides in stem cell adhesion, culture, organoid assembly, proliferation, and differentiation, describing the shortcomings of recombinant proteins and their full-length counterparts. Furthermore, we discuss the challenges of peptide applications in stem cell culture and materials design, as well as provide a brief outlook on future directions to advance peptide applications in boosting stem cell quality and scalability for clinical applications in tissue regeneration.

Biomechanical Comparison of Multilevel Lumbar Instrumented Fusions in Adult Spinal Deformity According to the Upper and Lower Fusion Levels: A Finite Element Analysis.

Multilevel lumbar fusion with posterior pedicle screw fixation is a widely performed surgical procedure for the management of adult spinal deformity. However, there has not been a comprehensive biomechanical study on the different types of fusion levels in terms of stability and possible complications. We aimed to investigate the biomechanical properties of multilevel lumbar fusion according to different types of upper and lower fusion levels. Six different types of fusions were performed using three-dimensional finite element models. Type A and B referred to the group of which upper fusion level was L1 and T10, respectively. Subtype 1, 2, and 3 referred to the group of which lower fusion level was L5, S1, and ilium, respectively (A1, L1-L5; A2, L1-S1; A3, L1-ilium; B1, T10-L5; B2, T10-S1; B3, T10-ilium). Flexion, extension, axial rotation, and lateral bending moments were applied, and the risk of screw loosening and failure and adjacent segment degeneration (ASD) was analyzed. Stress at the bone-screw interface of type B3 was lowest in overall motions. The risk of screw failure showed increasing pattern as the upper and lower levels extended in all motions. Proximal range of motion (ROM) increased as the lower fusion level changed from L5 to S1 and the ilium. For axial rotation, type B3 showed higher proximal ROM (16.2°) than type A3 (11.8°). In multilevel lumbar fusion surgery for adult spinal deformity, adding iliac screws and increasing the fusion level to T10-ilium may lower the risk of screw loosening. In terms of screw failure and proximal ASD, however, T10-ilium fusion has a higher potential risk compared with other fusion types. These results will contribute for surgeons to provide adequate patient education regarding screw failure and proximal ASD, when performing multilevel lumbar fusion.

Biomechanical Comparison and Three-Dimensional Analysis of Cement Distribution Patterns for Different Pedicle Screw Designs.

The purpose of this study to explore strategies for reducing cement leakage during cement-augmented pedicle screw fixation, we compared the cement distribution patterns and biomechanical strengths of different types of cement-augmented fenestrated screws and traditional cement-augmented techniques. We compared five screw groups in this study: (1) Cannulated screws (Cann); (2) distal one-hole screws (D1); (3) distal two-hole screws (D2); (4) middle two-hole screws (M2); and (5) traditional screws with a traditional cement injection technique (Trad). The screws were inserted into cancellous bone blocks using a controlled, adequate cement injection pressure (1.6-2.0 kg), and an appropriate cement viscosity. Center to screw tip distance, three-dimensional distribution, and pull-out strength for cement were compared between groups. The average distance between the cement center and the screw tip was highest in the M2 group, suggesting a higher risk of cement leakage into the spinal canal. The Trad group had the highest migration distance in the z-axis, also reflecting a higher risk of leakage into the spinal canal. The D1 group had the highest pull-out strength (253 ± 48.82 N and 797 ± 58.31 N) in bone blocks representing different degrees of osteoporosis, and the D2 group had the second highest pull-out strength in the severe osteoporosis model. Overall, D1 screws appeared to be the best option for optimizing biomechanical function and minimizing the risk of cement leakage into the spinal canal in patients with osteoporotic bone undergoing spinal surgery.

Real-Time Stress Analysis Affecting Nurse during Elective Spinal Surgery Using a Wearable Device.

Successful spinal surgery demands high levels of concentration and cooperation from participating health care workers. The intraoperative stress levels and concentration levels of surgeons have been studied previously; however, those of nurses are rarely studied. Therefore, the purpose of this study is to understand the stresses affecting surgical nurses by their participating role during spinal surgery. A total of 160 surgical stress records were obtained during 40 surgeries, including electroencephalography (EEG) signals and heart rate variability (HRV) from three orthopedic spinal surgeons and six nurses; concentration, tension level and physical stress were analyzed. Levels of both concentration and tension were significantly higher in circulating nurses during all surgical stages (p < 0.05). Both beats per minute and low frequency/high frequency ratios, which reflect physical stress, were higher in scrub nurses (p < 0.05). As the surgical experience of scrub nurses increased, the key parameters related to stress tended to decrease (p < 0.01). These results will contribute to understanding the pattern of intraoperative stress of surgical nurses, and therefore help in enhancing the teamwork of the surgical team for optimal outcomes.

Effects of carrier solutions on the viability and efficacy of canine adipose-derived mesenchymal stem cells.

BACKGROUND: Mesenchymal stem cells (MSCs) have favorable characteristics that render them a potent therapeutic tool. We tested the characteristics of MSCs after temporal storage in various carrier solutions, such as 0.9% saline (saline), 5% dextrose solution (DS), heparin in saline, and Hartmann's solution, all of which are approved by the U.S. Food and Drug Administration (FDA). Phosphate-buffered saline, which does not have FDA approval, was also used as a carrier solution. We aimed to examine the effects of these solutions on the viability and characteristics of MSCs to evaluate their suitability and efficacy for the storage of canine adipose-derived MSCs (cADMSCs). RESULTS: We stored the cADMSCs in the test carrier solutions in a time-dependent manner (1, 6, and 12 h) at 4 °C, and analyzed cell confluency, viability, proliferation, self-renewability, and chondrogenic differentiation. Cell confluency was significantly higher in 5% DS and lower in phosphate-buffered saline at 12 h compared to other solutions. cADMSCs stored in saline for 12 h showed the highest viability rate. However, at 12 h, the proliferation rate of cADMSCs was significantly higher after storage in 5% DS and significantly lower after storage in saline, compared to the other solutions. cADMSCs stored in heparin in saline showed superior chondrogenic capacities at 12 h compared to other carrier solutions. The expression levels of the stemness markers, Nanog and Sox2, as well as those of the MSC surface markers, CD90 and CD105, were also affected over time. CONCLUSION: Our results suggest that MSCs should be stored in saline, 5% DS, heparin in saline, or Hartmann's solution at 4 °C, all of which have FDA approval (preferable storage conditions: less than 6 h and no longer than 12 h), rather than storing them in phosphate-buffered saline to ensure high viability and efficacy.

Incidence and Surgery Rate of Idiopathic Scoliosis: A Nationwide Database Study.

Idiopathic scoliosis is the most common cause of three-dimensional deformities of the spine. Most of the previous studies have been cross-sectional studies to estimate the prevalence in the general population. An age-matched, population-based study is performed using nationwide databases between 2011 and 2015. The incidence rates of idiopathic scoliosis by age group, sex, and region are identified. We also investigate the pattern of medical institution use and the surgery rate of patients with idiopathic scoliosis. Our results show that a total of 268,372 patients were diagnosed with idiopathic scoliosis. The overall incidence was 0.497%, and the incidence for females was 1.44 times higher than for males. By age group, the incidence of adolescent idiopathic scoliosis in patients aged 10-14 years was 0.821% compared to 0.029%, 0.192%, and 0.709% for those patients aged 0-2, 3-9, and 15-19 years, respectively. Both male and female urban populations had higher incidences than rural populations with no age differences at diagnosis. Survival analysis confirmed that 0.7% of diagnosed patients underwent surgical treatment within five years. Understanding the epidemiology of idiopathic scoliosis is helpful in diagnosing high risk patients and monitoring surgical interventions.

Which Factors Affect the Stress of Intraoperative Orthopedic Surgeons by Using Electroencephalography Signals and Heart Rate Variability?

Can we recognize intraoperative real-time stress of orthopedic surgeons and which factors affect the stress of intraoperative orthopedic surgeons with EEG and HRV? From June 2018 to November 2018, 265 consecutive records of intraoperative stress measures for orthopedic surgeons were compared. Intraoperative EEG waves and HRV, comprising beats per minute (BPM) and low frequency (LF)/high frequency (HF) ratio were gathered for stress-associated parameters. Differences in stress parameters according to the experience of surgeons, intraoperative blood loss, and operation time depending on whether or not a tourniquet were investigated. Stress-associated EEG signals including beta 3 waves were significantly higher compared to EEG at rest for novice surgeons as the procedure progressed. Among senior surgeons, the LF/HF ratio reflecting the physical demands of stress was higher than that of novice surgeons at all stages. In surgeries including tourniquets, operation time was positively correlated with stress parameters including beta 1, beta 2, beta 3 waves and BPM. In non-tourniquet orthopedic surgeries, intraoperative blood loss was positively correlated with beta 1, beta 2, and beta 3 waves. Among orthopedic surgeons, those with less experience demonstrated relatively higher levels of stress during surgery. Prolonged operation time or excessive intraoperative blood loss appear to be contributing factors that increase stress.

Women with multiple gestations have an increased risk of development of hypertension in the future.

BACKGROUND: Multiple gestations are associated with an increased incidence of preeclampsia. However, there exists no evidence for an association between multiple gestations and development of hypertension(HTN) later in life. This study aimed to determine whether multiple gestations are associated with HTN beyond the peripartum period. METHODS: In this retrospective nationwide population-based study, women who delivered a baby between January 1, 2007, and December 31, 2008, and underwent a national health screening examination within one year prior to their pregnancy were included. Subsequently, we tracked the occurrence of HTN during follow-up until December 31, 2015, using International Classification of Diseases-10th Revision codes. RESULTS: Among 362,821 women who gave birth during the study period, 4,944 (1.36%) women had multiple gestations. The cumulative incidence of HTN was higher in multiple gestations group compared with singleton group (5.95% vs. 3.78%, p < 0.01, respectively). On the Cox proportional hazards models, the risk of HTN was increased in women with multiple gestations (HR 1.35, 95% CI 1.19, 1.54) compared with those with singleton after adjustment for age, primiparity, preeclampsia, atrial fibrillation, body mass index, blood pressure, diabetes mellitus, high total cholesterol, abnormal liver function test, regular exercise, and smoking status. CONCLUSIONS: Multiple gestations are associated with an increased risk of HTN later in life. Therefore, guidelines for the management of high-risk patients after delivery should be established.

Invasive dental procedures as risk factors for postoperative spinal infection and the effect of antibiotic prophylaxis.

AIM: To identify invasive dental procedures as a risk factor for postoperative spinal infection (PSI) and evaluate the effectiveness of antibiotic prophylaxis. MATERIALS AND METHODS: We analysed 229,335 patients who underwent spinal surgery with instrumentation from 2010 to 2017, using the nationwide database. The incidence of spinal infection 2 years after surgery was determined. Invasive dental procedures as a risk factor for PSI and the effects of antibiotic prophylaxis during this period were also analysed. RESULTS: A total of 15,346 patients (6.69%) were diagnosed with PSI. It was found that advanced age, male sex, and a high Charlson Comorbidity Index were risk factors for PSI. The risk of PSI did not increase following dental procedures (adjusted hazard ratio [HR] 0.850; 95% confidence interval [CI], 0.793-0.912) and was not affected by antibiotics (adjusted HR 1.097; 95% CI, 0.987-1.218). Patients who received dental treatment as early as 3 months after spinal surgery had the lowest risk of postoperative infection (adjusted HR 0.869; 95% CI, 0.795-0.950). CONCLUSIONS: Invasive dental procedure does not increase the risk of PSI, and antibiotic prophylaxis before dental procedure was not effective in preventing spinal infection.

Semi-Circumferential Decompression: Total En-Bloc Ligamentum Flavectomy to Treat Lumbar Spinal Stenosis with Two-Level Degenerative Spondylolisthesis.

INTRODUCTION: Despite technical developments in decompression without fusion, many studies still assert that instability could be increased in patients with spinal stenosis and lumbar degenerative spondylolisthesis after spinal decompression surgery without fusion. Thus, this study aimed to describe and assess the clinical outcomes of the semi-circumferential decompression (SCD) technique used for microsurgical en-bloc total ligamentum flavectomy with preservation of the facet joint in treating patients who have lumbar spinal stenosis with two-level degenerative spondylolisthesis. METHODS: We retrospectively analyzed the clinical and radiologic outcomes of 14 patients who had spinal stenosis with two-level Meyerding grade I degenerative spondylolisthesis. We evaluated improvements in back pain and radiating pain using a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). We have also examined the occurrence of spinal instability on a radiological exam using slip percentage and slip angle. RESULTS: The mean VAS score of back pain and radiating pain has been determined to decrease significantly from 6.7 to 3.3 and from 8.6 to 2.7, respectively. Meanwhile, the ODI score significantly improved from 27.3 preoperatively to 9.8 postoperatively. Statistically significant change was not observed in the slip percentage in both upper and lower levels. Dynamic slip percentage, which is defined as the difference in the slip percentage between flexion and extension, also did not significantly change. No statistically significant change was found in the slip angle and dynamic slip angle. CONCLUSIONS: SCD is a recommendable procedure that can improve clinical results. This procedure does not cause spinal instability when treating patients who have spinal stenosis with two-level degenerative spondylolisthesis.

Incidence rate of congenital scoliosis estimated from a nationwide health insurance database.

To investigate the epidemiology of congenital scoliosis (CS) and treatment trends. An age-matched, nationwide, population-based study was conducted using the National Health Insurance and Health Insurance Review and Assessment databases from 2010 to 2015. Data regarding the diagnosis and treatment of scoliosis were extracted using International Classifications of Diseases, 10th revision codes. The age-matched normal population was determined from the Korean Statistical Information Service database. We analyzed the incidence rate of CS according to age and sex, as well as the proportion of surgically treated patients. A total of 1664 patients (aged 0-19 years) were diagnosed with CS. The overall average incidence rate of CS over the 5-year period was 3.08 per 100,000 persons, with the highest and second highest rates at 0 years and 12-16 years of age, respectively. The incidence rate stratified by age ranged from 1.5 to 20.1 per 100,000 persons among the age-matched normal population, with peaks at 0 years of age and the second growth spurt in adolescence (12-16 years for males; 10-14 years for females). Anterior surgery was rarely performed; posterior surgery was performed in 92 patients (5.5% of all patients), with the highest prevalence (56.5%) in patients diagnosed at 10-14 years of age. The overall average incidence rate of CS over a 5-year period was 3.08 per 100,000 persons. Only 5.5% of patients underwent surgery within 5 years after the initial diagnosis.

Effects of endogenous and exogenous oestrogen exposure on hearing level in postmenopausal women: A cross-sectional study.

OBJECTIVE: To investigate the effect of endogenous and exogenous oestrogen exposure on hearing levels in postmenopausal women. STUDY DESIGN: Retrospective cross-sectional study. SETTING: Population-based survey data collected by the Korean National Health and Nutrition Survey between 1 January 2010 and 31 December 2012. SUBJECTS AND METHODS: Participants comprised 3653 postmenopausal women. Detailed histories for reproductive factors and data on the use of hormone replacement therapy were obtained through health questionnaires and otologic examinations, including pure-tone audiogram and otoscopic findings. Complex-sample linear regression models controlling for confounding factors were generated to determine whether hormone-related factors were associated with hearing loss. RESULTS: Women who experienced a longer duration of oestrogen exposure had better hearing compared to those who do not in multivariate model adjusting for confounding factors with a lower adjusted beta coefficient of hearing threshold (ß = -0.18, 95% confidence interval = -0.3 to -0.07, P = .002). The results also suggested that hormone replacement therapy may be beneficial for attenuating hearing loss (ß = -1.22, 95% confidence interval = -2.19 to -0.25, P = .014), particularly in the high-frequency range from 3 to 6 KHz. CONCLUSION: A longer duration of lifetime oestrogen exposure (LEE) and the use of hormone replacement therapy are likely to attenuate hearing loss. These epidemiologic data provide evidence that oestrogen may be beneficial for attenuating age-related hearing decline.

Hand grip strength as a surrogate marker for postoperative changes in spinopelvic alignment in patients with lumbar spinal stenosis.

There are a few studies on the postoperative changes in sagittal alignment and corresponding factors, including hand grip strength (HGS) and muscle performance tests for lumbar spinal stenosis (LSS). Thus, we aimed to determine whether HGS can be a surrogate marker for global sagittal alignment changes after decompression with fusion surgery for LSS. This retrospective observational study included 91 patients who underwent spine fusion surgery for LSS. Radiological spinopelvic parameters, including sagittal vertical axis (SVA), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), global tilt (GT), and T1 pelvic angle (T1PA), were analyzed preoperatively and 1 year after posterior decompression and fusion surgery. To assess muscle performance, the 6-m walk (SMT), timed up and go (TUGT), and sit-to-stand (STS) tests were conducted. The relationship between HGS and postoperative SVA was examined through multiple linear regression analysis. Additionally, the relationship between HGS and preoperative/postoperative radiologic spinopelvic parameters and muscle performance test results was analyzed through Pearson's correlation. HGS was significantly correlated with age, preoperative and postoperative SVA, and the muscle performance tests. Furthermore, HGS was a factor that can significantly influence postoperative SVA changes in multiple linear regression analyses. Therefore, HGS may be a good predictor of postoperative SVA change.

Hand grip strength can predict clinical outcomes and risk of falls after decompression and instrumented posterolateral fusion for lumbar spinal stenosis.

BACKGROUND CONTEXT: There has been limited research on the association between hand grip strength (HGS) as one of the diagnostic criteria for sarcopenia and surgical outcomes of lumbar spinal stenosis (LSS). PURPOSE: We aimed to determine the effect of HGS on surgical outcomes and risk of fall in patients with LSS. STUDY DESIGN: This is a retrospective observational study. PATIENT SAMPLE: We included 200 patients who underwent spinal surgery for LSS. OUTCOME MEASURES: We recorded clinical outcome parameters, including Oswestry Disability Index (ODI), Euro-QOL (EQ-5D), and visual analog scale (VAS) scores for back or leg pain. To assess the risk of fall we used HGS and four functional mobility tests (alternative step test, six-meter walk test, timed up and go test, sit-to-stand test). MATERIALS AND METHODS: ODI, EQ-5D, and VAS scores for back and leg pain were assessed preoperatively and 1 year after surgery. The four functional mobility tests were assessed at each time point during the 1-year follow-up period to assess the risk of fall in patients with LSS. We divided the patient cohort according to sex and allocated them into two different groups based on HGS: high HGS (≥26 kg for men, n=26; ≥18 kg for women, n=35), and low HGS (<26 kg for men, n=48; <18 kg for women, n=91). The pre- and postoperative ODI, EQ-5D, and VAS scores for back and leg pain, as well as the functional mobility test results, and demographic data were compared between the two groups using independent t tests. Correlations between HGS and clinical outcome parameters were analyzed using Pearson correlation. RESULTS: In women and men, HGS correlated with the preoperative/postoperative ODI (r1=-0.217/r2=-0.345 in women, and r1=-0.384/r2=-0.411 in men) and EQ-5D scores (r1=0.190/r2=0.309 in women, and r1=0.373/r2=0.467 in men). HGS also correlated with the four postoperative results for the functional mobility tests: alternative step test (r=-0.238 in women, r=-0.431 in men), six-meter walk test (r=-0.232 in women, r=-0.282 in men), timed up and go test (r=-0.285 in women, r=-0.359 in men), and sit-to-stand test (r=-0.238 in women, r=-0.251 in men). The preoperative and postoperative ODI and EQ-5D scores in the high HGS group were superior to those in the low HGS group. Among the four functional mobility tests, preoperative and postoperative six-meter walk test results showed improvements in the high HGS group. CONCLUSIONS: Considering the multifactorial nature of falls, HGS may be a useful surrogate marker for predicting the risk of falls and clinical outcomes in patients with LSS.

Risk Factors of Clostridium Difficile Infection After Spinal Surgery: National Health Insurance Database.

The purpose of this study was to evaluate risk factors of Clostridium Difficile infection (CDI) after spinal surgery using the Health Insurance Review and Assessment Service (HIRA) data. The incidence of postoperative CDI was investigated using HIRA data from 2012 to 2016. Cases involving CDI that occurred within a 30-day postoperative period were identified. Risk factors, including age, sex, comorbidities, postoperative infection, spinal surgery procedure, type of antibiotic, and duration of antibiotic use, were evaluated. Duration of hospital stay, medical cost, and mortality were also evaluated. In total, 71,322 patients were included. Presumed cases of CDI were identified in 57 patients, with CDI rate of 0.54 per 10,000 patient days. Advanced age, staged operation, postoperative infection, and the use of multiple antibiotics were significant risk factors. First-generation cephalosporins were shown to be associated with a lower incidence of CDI. CDI was also associated with longer hospital stays and increased medical cost, and it was an independent risk factor for increased mortality. Extra attention should be paid to patients at high risk for the development of postoperative CDI, and unnecessary use of multiple antibiotics should be avoided. Level of Evidence: Level III, retrospective cohort study.

3,2'-Dihydroxyflavone Improves the Proliferation and Survival of Human Pluripotent Stem Cells and Their Differentiation into Hematopoietic Progenitor Cells.

Efficient maintenance of the undifferentiated status of human pluripotent stem cells (hiPSCs) is crucial for producing cells with improved proliferation, survival and differentiation, which can be successfully used for stem cell research and therapy. Here, we generated iPSCs from healthy donor peripheral blood mononuclear cells (PBMCs) and analyzed the proliferation and differentiation capacities of the generated iPSCs using single cell NGS-based 24-chromosome aneuploidy screening and RNA sequencing. In addition, we screened various natural compounds for molecules that could enhance the proliferation and differentiation potential of hiPSCs. Among the tested compounds, 3,2'-dihydroxyflavone (3,2'-DHF) significantly increased cell proliferation and expression of naïve stemness markers and decreased the dissociation-induced apoptosis of hiPSCs. Of note, 3,2'-DHF-treated hiPSCs showed upregulation of intracellular glutathione (GSH) and an increase in the percentage of GSH-high cells in an analysis with a FreSHtracer system. Interestingly, culture of the 3,2'-DHF-treated hiPSCs in differentiation media enhanced their mesodermal differentiation and differentiation into CD34+ CD45+ hematopoietic progenitor cells (HPC) and natural killer cells (NK) cells. Taken together, our results demonstrate that the natural compound 3,2'-DHF can improve the proliferation and differentiation capacities of hiPSCs and increase the efficiency of HPC and NK cell production from hiPSCs.