Privacy-Preserving Prediction of Postoperative Mortality in Multi-Institutional Data: Development and Usability Study.

BACKGROUND: To circumvent regulatory barriers that limit medical data exchange due to personal information security concerns, we use homomorphic encryption (HE) technology, enabling computation on encrypted data and enhancing privacy. OBJECTIVE: This study explores whether using HE to integrate encrypted multi-institutional data enhances predictive power in research, focusing on the integration feasibility across institutions and determining the optimal size of hospital data sets for improved prediction models. METHODS: We used data from 341,007 individuals aged 18 years and older who underwent noncardiac surgeries across 3 medical institutions. The study focused on predicting in-hospital mortality within 30 days postoperatively, using secure logistic regression based on HE as the prediction model. We compared the predictive performance of this model using plaintext data from a single institution against a model using encrypted data from multiple institutions. RESULTS: The predictive model using encrypted data from all 3 institutions exhibited the best performance based on area under the receiver operating characteristic curve (0.941); the model combining Asan Medical Center (AMC) and Seoul National University Hospital (SNUH) data exhibited the best predictive performance based on area under the precision-recall curve (0.132). Both Ewha Womans University Medical Center and SNUH demonstrated improvement in predictive power for their own institutions upon their respective data's addition to the AMC data. CONCLUSIONS: Prediction models using multi-institutional data sets processed with HE outperformed those using single-institution data sets, especially when our model adaptation approach was applied, which was further validated on a smaller host hospital with a limited data set.

H1N1 nanobody development and therapeutic efficacy verification in H1N1-challenged mice.

Influenza A virus causes numerous deaths and infections worldwide annually. Therefore, we have considered nanobodies as a potential treatment for patients with severe cases of influenza. We developed a nanobody that was expected to have protective efficacy against the A/California/04/2009 (CA/04; pandemic 2009 flu strain) and evaluated its therapeutic efficacy against CA/04 in mice experiments. This nanobody was derived from the immunization of the alpaca, and the inactivated CA/04 virus was used as an immunogen. We successfully generated a nanobody library through bio-panning, phage ELISA, and Bio-layer interferometry. Moreover, we confirmed that administering nanobodies after lethal doses of CA/04 reduced viral replication in the lungs and influenza-induced clinical signs in mice. These research findings will help to develop nanobodies as viral therapeutics for CA/04 and other infectious viruses.

Gastric Metastasis from Gastric-Type Mucinous Adenocarcinoma of Uterine Cervix: A Case Report.

Gastric metastasis (GM) from cervical cancer is extremely rare, and only a few cases have been reported in the English literature. Gastric-type mucinous adenocarcinomas (GAS) of the uterine cervix are rare. GAS is an aggressive cancer commonly found in advanced stages; however, GM has not been reported. This study presents a rare case of GM from GAS of the uterine cervix in a 61-year-old female and describes the radiological findings of both the GM and cervical mucinous adenocarcinoma. GM appeared as a poor enhancing submucosal mass. The cervical mucinous adenocarcinoma appeared as an infiltrating mass with poor contrast enhancement. It exhibited mildly high and low signal intensities on the diffusion-weighted image and apparent diffusion coefficient map, respectively. This case is extremely rare and challenging to diagnose; however, if cervical cancer is an human papillomavirus-independent GAS type and a submucosal lesion is found in the stomach, the possibility of metastasis with a pattern similar to our case could be considered.

Boeravinone B, a natural rotenoid, inhibits osteoclast differentiation through modulating NF-κB, MAPK and PI3K/Akt signaling pathways.

Osteoporosis is a major public health concern, which requires novel therapeutic strategies to prevent or mitigate bone loss. Natural compounds have attracted attention as potential therapeutic agents due to their safety and efficacy. In this study, we investigated the regulatory activities of boeravinone B (BOB), a natural rotenoid isolated from the medicinal plant Boerhavia diffusa, on the differentiation of osteoclasts and mesenchymal stem cells (MSCs), the two main cell components responsible for bone remodeling. We found that BOB inhibited osteoclast differentiation and function, as determined by TRAP staining and pit formation assay, with no significant cytotoxicity. Furthermore, our results showing that BOB ameliorates ovariectomyinduced bone loss demonstrated that BOB is also effective in vivo. BOB exerted its inhibitory effects on osteoclastogenesis by downregulating the RANKL/RANK signaling pathways, including NF-κB, MAPK, and PI3K/Akt, resulting in the suppression of osteoclast-specific gene expression. Further experiments revealed that, at least phenomenologically, BOB promotes osteoblast differentiation of bone marrow-derived MSCs but inhibits their differentiation into adipocytes. In conclusion, our study demonstrates that BOB inhibits osteoclastogenesis and promotes osteoblastogenesis in vitro by regulating various signaling pathways. These findings suggest that BOB has potential value as a novel therapeutic agent for the prevention and treatment of osteoporosis. [BMB Reports 2023; 56(10): 545-550].

Diagnostic and Prognostic Values of Neutrophil Reactivity Intensity (NEUT-RI) in Pediatric Systemic Inflammatory Response Syndrome and Sepsis.

OBJECTIVE: Recent advances in hematology analyzers have generated cell population data (CPD), which quantify features of cells. The characteristics of CPD in pediatric systemic inflammatory response syndrome (SIRS) and sepsis were evaluated with 255 patients. METHODS: The ADVIA 2120i hematology analyzer was used for measurement of the delta neutrophil index (DN) including DNI and DNII. The XN-2000 was used for measurement of immature granulocytes (IG), neutrophil reactivity intensity (NEUT-RI), neutrophil granularity intensity (NEUT-GI), reactive lymphocytes (RE-LYMP), antibody synthesizing lymphocytes (AS-LYMP), RBC hemoglobin equivalent (RBC-He), and difference between RBC and reticulocyte hemoglobin equivalent (Delta-He). Measurement of high-sensitivity C-reactive protein (hsCRP) was performed using the Architect ci16200. RESULTS: The area under the receiver operating characteristic curve (AUC) values with confidence interval (CI) of IG (0.65, CI 0.58-0.72), DNI (0.70, CI 0.63-0.77), DNII (0.69, CI 0.62-0.76), and AS-LYMP (0.58, CI 0.51-0.65) were significant for diagnosis of sepsis. The levels of IG, NEUT-RI, DNI, DNII, RE-LYMP, and hsCRP exhibited gradual increasing trends from control to sepsis. In Cox regression analysis, the highest hazard ratio was observed for NEUT-RI (39.57, CI 4.87-321.75), higher than those for hsCRP (12.33, CI 2.49-61.12) and DNII (16.13, CI 1.98-131.08). IG (10.34, CI 2.47-43.26), DNI (11.60, CI 2.34-57.49), and RE-LYMP (8.20, CI 1.96-34.33) also showed high hazard ratios. CONCLUSION: NEUT-RI along with DNI and DNII can provide additional information regarding the diagnosis of sepsis and prediction of mortality in the pediatric ward.

MELD-GRAIL-Na Is a Better Predictor of Mortality Than MELD in Korean Patients with Cirrhosis.

Background and Objectives: The Child-Pugh (CP) score and Model for End-Stage Liver Disease (MELD) are classical systems for predicting mortality in patients with liver cirrhosis (LC). The MELD-GFR assessment in liver disease-sodium (MELD-GRAIL-Na) was designed to better reflect renal function and, therefore, provide better mortality predictions. This study aimed to compare the prediction accuracy of MELD-GRAIL-Na compared to CP and MELD in predicting short-term (1- and 3-month) mortality in Korean patients. Materials and Methods: Medical records of patients with LC admitted to the Konkuk University Hospital from 2015 to 2020 were retrospectively reviewed. Predictive values of the CP, MELD, and MELD-GRAIL-Na for 1-month and 3-month mortality were calculated using the area under the receiver operating curve (AUROC) and were compared using DeLong's test. Results: In total, 1249 patients were enrolled; 102 died within 1 month, and 146 within 3 months. AUROCs of CP, MELD, and MELD-GRAIL-Na were 0.831, 0.847, and 0.857 for 1-month mortality and 0.837, 0.827, and 0.835 for 3-month mortality, respectively, indicating no statistical significance. For patients with CP classes B and C, AUROCs of CP, MELD, and MELD-GRAIL-Na were 0.782, 0.809, and 0.825 for 1-month mortality and 0.775, 0.769, and 0.786 for 3-month mortality, respectively. There was a significant difference between CP and MELD-GRAIL-Na in predicting 1-month mortality (p = 0.0428) and between MELD and MELD-GRAIL-Na in predicting 1-month (p = 0.0493) and 3-month mortality (p = 0.0225). Conclusions: Compared to CP and MELD, MELD-GRAIL-Na was found to be a better and more useful system for evaluating short-term (1- and 3-month) mortality in Korean patients with cirrhosis, especially those with advanced cirrhosis (CP class B and C).

Isolation of High Purity Mouse Mesenchymal Stem Cells through Depleting Macrophages Using Liposomal Clodronate.

BACKGROUND: The use of mouse bone marrow mesenchymal stem cells (mBMSCs) represents a promising strategy for performing preclinical studies in the field of cell-based regenerative medicine; however, mBMSCs obtained via conventional isolation methods have two drawbacks, i.e., (i) they are heterogeneous due to frequent macrophage contamination, and (ii) they require long-term culturing for expansion. METHODS: In the present study, we report a novel strategy to generate highly pure mBMSCs using liposomal clodronate. This approach is based on the properties of the two cell populations, i.e., BMSCs (to adhere to the plasticware in culture dishes) and macrophages (to phagocytose liposomes). RESULTS: Liposomal clodronate added during the first passage of whole bone marrow culture was selectively engulfed by macrophages in the heterogeneous cell population, resulting in their effective elimination without affecting the MSCs. This method allowed the generation of numerous high-purity Sca-1+CD44+F4/80- mBMSCs (> 95%) with just one passaging. Comparative studies with mBMSCs obtained using conventional methods revealed that the mBMSCs obtained in the present study had remarkably improved experimental utilities, as demonstrated by in vitro multilineage differentiation and in vivo ectopic bone formation assays. CONCLUSION: Our newly developed method, which enables the isolation of mBMSCs using simple and convenient protocol, will aid preclinical studies based on the use of MSCs.

Evaluation of cellular response and drug delivery efficacy of nanoporous stainless steel material.

OBJECTIVE: Various surface modification techniques that can further improve the function and usability of stainless steel as a medical device have been reported. In the present study, the physical and biological properties of nanoporous stainless steel as well as its usefulness for drug delivery were assessed. METHODS: The specimen was prepared with a circular disk shape (15 mm in diameter and 1 mm in thickness). The disk was subjected to electropolishing at a constant voltage of 20 V and 10 A for 10 min in an acidic environment (50% H2SO4). Everolimus (EVL) was used as a testing drug for drug-loading capacity of the material surface and release kinetics. The physiobiological properties of the material were assessed using platelet adhesion, and smooth muscle cell (SMC) adhesion, migration, and proliferation assays. RESULTS: The surface roughness of the postpolishing group was greater than that of the nonpolishing group. Platelet adhesion and SMC adhesion and migration were inhibited in the postpolishing group compared to those in the prepolishing group. In the postpolishing group, the total amount of EVL on the surface (i.e., drug storage rate) was higher and the drug release rate was lower, with half the amount of the EVL released within 4 days compared with only 1 day for that of the prepolishing group. CONCLUSION: Taken together, this stainless steel with a nanoporous surface could be used as a medical device for controlling cellular responses and carrying drugs.

Wetting Property Modification of Al2O3 by Helium Ion Irradiation: Effects of Beam Energy and Fluence on Contact Angle.

In imparting wetting properties, a fabrication process without the addition of new compounds and deposition of coating layers would be the most desirable because it does not introduce additional complexities. Hence, the ion beam irradiation technique is used as it enables the chemistry of materials to be modified through simple adjustments of irradiation parameters such as the type of accelerated particles, beam energy, and fluence. In this study, the hydrophilicity of alumina surfaces was weakened by irradiating He ion beams of different energy levels (200 keV and 20 MeV). These transitions become more pronounced as the total beam fluence increases. In low-energy irradiation, the effect of irradiation is predominant near the surface, and hydrophilicity is weakened by the increase in carbon adsorption and suppression of dissociative adsorption of water molecules owing to the introduction of oxygen vacancies. In contrast, nuclear transmutations are induced by irradiation with high-energy beams. Consequently, fluorine is generated, and hydrophobic functional groups are formed on the surface. By varying the beam conditions, the wetting properties of the target ceramic can be controlled to the desired level, which is required in various industries, via appropriate adjustments of the beam parameters. In addition, the beam irradiation technique may be applicable to all ceramic materials, including lattice oxygen and alumina.

Anti-cancer effects of the aqueous extract of Orostachys japonica A. Berger on 5-fluorouracil-resistant colorectal cancer via MAPK signalling pathways in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Orostachys japonica A. Berger, also known as Wa-song in Korea, has traditionally been used as a folk medicine, but the potential anti-cancer effects of aqueous extract of Orostachys japonica (OJe) have not yet been thoroughly investigated. AIM OF THE STUDY: To evaluate the anti-cancer effects of OJe, its possible mechanisms of action were investigated in 5-fluorouracil (5-FU) resistant SNU-C5/5-FUR colorectal cancer cells. MATERIALS AND METHODS: The functional compounds of OJe were identified with high performance liquid chromatography. The anti-cancer effects of OJe in SNU-C5/5-FUR cells were investigated by a cell viability assays, flow cytometry analysis, and a subcutaneous xenograft model employing BALB/c-nude mice. Possible signalling pathways were assayed with Western blotting. RESULTS: OJe (250 µg/ml) showed anti-cancer effects in SNU-C5/5-FUR cells, that were mediated via apoptosis as well as cell cycle arrest at the G0/G1 phase. Gallic acid and (-)-epicatechin, the major functional components of OJe, induced cell cycle arrest. OJe treatment (250 mg/kg, p.o.) produced a significant anti-proliferative effect in the xenograft model via decreased ß-catenin/GSK3ß and increased p27 expression. OJe treatment significantly activated ERK and p38 both in vitro and in vivo. CONCLUSIONS: These results suggest that OJe has anti-proliferative effects on 5-FU-resistant colorectal cancer cells via regulation of MAPK signalling pathways.

Genomic Analysis and Assessment of Melanin Synthesis in Amorphotheca resinae KUC3009.

This study reports the draft genome of Amorphotheca resinae KUC30009, a fungal isolate with promising industrial-scale melanin production potential. The mechanisms for melanin or melanin-related pigment formation of this strain were examined through bioinformatic and biochemical strategies. The 30.11 Mb genome of A. resinae contains 9638 predicted genes. Genomic-based discovery analyses identified 14 biosynthetic gene clusters (BGCs) associated with secondary metabolite production. Moreover, genes encoding a specific type 1 polyketide synthase and 4-hydroxynaphthalene reductase were identified and predicted to produce intermediate metabolites of dihydroxy naphthalene (DHN)-melanin biosynthesis pathway, but not to DHN-melanin. These findings were further supported by the detection of increased flaviolin concentrations in mycelia and almost unchanged morphologies of the culture grown with tricyclazole. Apart from this, the formation of melanin in the culture filtrate appeared to depend on the laccase-like activity of multi-copper oxidases. Simultaneously, concentrations of nitrogen-containing sources decreased when the melanin formed in the media. Interestingly, melanin formation in the culture fluid was proportional to laccase-like activity. Based on these findings, we proposed novel strategies for the enhancement of melanin production in culture filtrates. Therefore, our study established a theoretical and methodological basis for synthesizing pigments from fungal isolates using genomic- and biochemical-based approaches.

Mononeuropathy multiplex associated with systemic vasculitis: A case report.

BACKGROUND: Vasculitis, a systemic disorder with inflammation of blood vessel walls, can develop broad spectrum of signs and symptoms according to involvement of various organs, and therefore, early diagnosis of vasculitis is challenging. We herein describe a patient who developed a special case of systemic vasculitis with mononeuropathy multiplex, rectal perforation and antiphospholipid syndrome (APS) presented with pulmonary embolism. CASE SUMMARY: A 61-year-old woman visited hospital with complaints of myalgia and occasional fever. She was initially diagnosed as proctitis and treated with antibiotics, however, there was no improvement. In addition, she also complained right foot drop with hypesthesia, and left 2nd and 3rd finger tingling sensation. She underwent nerve conduction study for evaluation, and it revealed sensorimotor polyneuropathy in the left arm and bilateral legs. Subsequent sural nerve biopsy strongly suggested vasculitic neuropathy. Based on nerve biopsy and clinical manifestation, she was diagnosed with vasculitis and treated with immuno-suppressive therapy. During treatment, sudden rectal perforation and pulmonary thromboembolism occurred, and further laboratory study suggested probable concomitant APS. Emergency Hartmann operation was performed for rectal perforation, and anti-coagulation therapy was started for APS. After few cycles of immunosuppressive therapy, tingling sensation and weakness in her hand and foot had been partially recovered and vasculitis was considered to be stationary. CONCLUSION: Vasculitis can be presented with a variety of signs and symptoms, therefore, clinicians should always consider the possibility of diagnosis.

Mainstreaming of Health Equity in Infectious Disease Control Policy During the COVID-19 Pandemic Era.

The Korean government's strategy to combat coronavirus disease 2019 (COVID-19) has focused on non-pharmaceutical interventions, such as social distancing and wearing masks, along with testing, tracing, and treatment; overall, its performance has been relatively good compared to that of many other countries heavily affected by COVID-19. However, little attention has been paid to health equity in measures to control the COVID-19 pandemic. The study aimed to examine the unequal impacts of COVID-19 across socioeconomic groups and to suggest potential solutions to tackle these inequalities. The pathways linking social determinants and health could be entry points to tackle the unequal consequences of this public health emergency. It is crucial for infectious disease policy to consider social determinants of health including poor housing, precarious working conditions, disrupted healthcare services, and suspension of social services. Moreover, the high levels of uncertainty and complexity inherent in this public health emergency, as well as the health and socioeconomic inequalities caused by the pandemic, underscore the need for good governance other than top-down measures by the government. We emphasize that a people-centered perspective is a key approach during the pandemic era. Mutual trust between the state and civil society, strong accountability of the government, and civic participation are essential components of cooperative disaster governance.

Bone Generation Following Repeated Administration of Recombinant Bone Morphogenetic Protein 2.

BACKGROUND: The delivery of recombinant human bone morphogenetic protein 2 (rhBMP2) by using various carriers has been used to successfully induce bone formation in many animal models. However, the effect of multiple administration of rhBMP2 on bone formation and BMP2 antibody production has not been determined. Our aim was to examine the bone formation activity of rhBMP2 and serum levels of anti-BMP2 antibodies following the repeated administration of rhBMP2 in mice. METHODS: Absorbable collagen sponges or polyphosphazene hydrogels containing rhBMP2 were subcutaneously implanted or injected into one side on the back of six-week-old C57BL/6 mice. Three or 4 weeks later, the same amount of rhBMP2 was administered again with the same carrier into the subcutaneous regions on the other side of the back or into calvarial defects. The effects of a single administration of rhBMP2 on the osteoinductive ability in the ectopic model were compared with those of repeated administrations. In vivo ectopic or orthotopic bone formation was evaluated using microradiography and histological analyses. Serum concentrations of anti-rhBMP2 antibodies were measured by ELISAs. RESULTS: Re-administration of the same amount of rhBMP2 into the subcutaneous area showed a comparable production of ectopic bone as after the first administration. The bone forming ability of repeated rhBMP2 administrations was equal to that of single rhBMP2 administration. The administration of rhBMP2 into calvarial defects, following the first subcutaneous administration of rhBMP2 on the back, completely recovered the defect area with newly regenerated bone within 3 weeks. Repeated administration of rhBMP2 at 4-week intervals did not significantly alter the serum levels of anti-BMP2 antibodies and did not induce any inflammatory response. The serum obtained from rhBMP2-exposed mice had no effect on the ability of rhBMP2 to induce osteogenic gene expressions in MC3T3-E1. CONCLUSION: We suggest that the osteoinductive ability of rhBMP2 is not compromised by repeated administrations. Thus, rhBMP2 can be repeatedly used for bone regeneration at various sites within a short duration.

Hydrophilicity Improvement of Polymer Surfaces Induced by Simultaneous Nuclear Transmutation and Oxidation Effects Using High-Energy and Low-Fluence Helium Ion Beam Irradiation.

Two commodity polymers, polystyrene (PS) and high-density polyethylene (HDPE), were irradiated by high-energy He ion beams at low fluence to examine the wettability changes at different fluences. The water contact angles of the PS and HDPE surfaces were reduced from 78.3° to 46.7° and 81.5° to 58.5°, respectively, upon increasing the fluence from 0 to 1 × 1013 He2+/cm2 for irradiation durations ≤4 min. Surface analyses were performed to investigate these wettability changes. Surface texture evaluations via scanning electron and atomic force microscopies indicated non-remarkable changes by irradiation. However, the chemical structures of the irradiated polymer surfaces were notable. The high-energy He ions induced nuclear transmutation of C to N, leading to C-N bond formation in the polymer chains. Further, C-O and C=O bonds were formed during irradiation in air because of polymer oxidation. Finally, amide and ester groups were generated by irradiation. These polar groups improved hydrophilicity by increasing surface energies. Experiments with other polymers can further elucidate the correlation between polymer structure and surface wettability changes due to high-energy low-fluence He ion irradiation. This method can realize simple and effective utilization of commercial cyclotrons to tailor polymer surfaces without compromising surface texture and mechanical integrity.

Correlation between radiographic knee osteoarthritis and lifetime cigarette smoking amount in a Korean population: A cross-sectional study.

Although the inverse correlation between smoking and degenerative arthritis is controversial, quantitative analysis of the correlation between lifetime cigarette smoking amount and degenerative arthritis has not been performed. We investigated the correlation between knee radiographic osteoarthritis (ROA) and lifetime cigarette smoking amount in the general population.This cross-sectional study used the Fifth and Sixth Korean National Health and Nutrition Examination Survey (2010-2013) data. Subjects included 11,638 community-dwelling adults aged ≥50 years. Knee ROA was defined as a Kellgren/Lawrence grade ≥2 on plain radiography. Lifetime cigarette smoking amount was calculated in terms of pack-year and further divided into quartile groups. Independent correlation between smoking and knee ROA was determined using odds ratios (OR) adjusted for age, sex, obesity, physical activity, and household income on multivariate logistic regression analysis.Knee ROA prevalence was 37.3%; prevalence of lifetime cigarette smokers was 26.0%. Subjects with knee ROA had higher mean age, female sex ratio, and body mass index but lower physical activity level. The adjusted logistic regression model revealed that female sex (OR, 2.110; 95% confidence interval [CI], 1.895-2.349) was significantly associated with knee ROA. Older age, obesity, and lower household income were positively correlated with knee ROA. Second-and fourth-quartile groups of smokers had the lower ROA prevalence than never-smokers (OR, 0.800; 95% CI, 0.643-0.99; OR, 0.812; 95% CI, 0.684-0.965, respectively).An inverse correlation with knee ROA was confirmed in mid-light to heavy smokers. Prospective studies are needed to reveal whether knee ROA involves smoking.

CUEDC2 controls osteoblast differentiation and bone formation via SOCS3-STAT3 pathway.

The CUE domain-containing 2 (CUEDC2) protein plays critical roles in many biological processes, such as the cell cycle, inflammation, and tumorigenesis. However, whether CUEDC2 is involved in osteoblast differentiation and plays a role in bone regeneration remains unknown. This study investigated the role of CUEDC2 in osteogenesis and its underlying molecular mechanisms. We found that CUEDC2 is expressed in bone tissues. The expression of CUEDC2 decreased during bone development and BMP2-induced osteoblast differentiation. The overexpression of CUEDC2 suppressed the osteogenic differentiation of precursor cells, while the knockdown of CUEDC2 showed the opposite effect. In vivo studies showed that the overexpression of CUEDC2 decreased bone parameters (bone volume, bone area, and bone mineral density) during ectopic bone formation, whereas its knockdown increased bone volume and the reconstruction percentage of critical-size calvarial defects. We found that CUEDC2 affects STAT3 activation by regulating SOCS3 protein stability. Treatment with a chemical inhibitor of STAT3 abolished the promoting effect of CUEDC2 silencing on osteoblast differentiation. Together, we suggest that CUEDC2 functions as a key regulator of osteoblast differentiation and bone formation by targeting the SOCS3-STAT3 pathway. CUEDC2 manipulation could serve as a therapeutic strategy for controlling bone disease and regeneration.

Biomechanical influences of gait patterns on knee joint: Kinematic & EMG analysis.

BACKGROUND: As lumbar spinal stenosis commonly occurs between the L2 and L5 segments, hip abductors are easily affected. However, studies regarding the gait pattern in these patients from the coronal plane have not yet been conducted. PURPOSE: To determine the effects of lumbar spinal stenosis on the gait pattern (stride width and femorotibial angle) and hip abductor surface electromyography in varied stride widths compared with healthy individuals. STUDY DESIGN: Prospective case-control study. METHODS: Seventeen patients and 20 healthy individuals were enrolled. Each participant completed three gait assessments in their normal gait, adducted gait and abducted gait. The femorotibial angle and surface electromyography signals were measured. Pain scores was used to quantify the degree of discomfort in the gluteal area and medial side of the knee. RESULTS: When the hip abductors' surface electromyography signals were normalized by quadriceps femoris, patients group showed significantly higher activation ratios throughout all gait patterns. Generally, surface electromyography signals and ratios were significantly higher during abducted gait compared with a normal gait. Femorotibial angle became significantly closer to the varus in healthy individuals during abducted gait. When femorotibial angle during normal gait was compared between the two groups, patients group exhibited slightly wider stride width and FTA significantly closer to the varus. Pain scores were significantly higher in the patient group and during abducted gait. CONCLUSION: Wider stride widths indicated increased relative activation of the hip abductors, closer proximity between femorotibial angle and varus, and increased pain scores for discomfort. The same tendency was observed in patients group when compared with healthy individuals. Widening of stride width in patients group despite abductor weakness suggests that additional muscle recruitment may be needed to maintain balance. Furthermore, such a distinctive gait pattern exerts increased loading on the medial knee, relating to the escalated risk of degenerative knee osteoarthritis.

The primary cilium directs osteopontin-induced migration of mesenchymal stem cells by regulating CD44 signaling and Cdc42 activation.

The primary cilium acts as a sensory organelle with diverse receptors and ion channels to detect extracellular cues and regulate cellular functions, including cell migration. The migration of mesenchymal stem cells (MSCs) to bone remodeling sites is important for bone homeostasis. Recently, we have suggested that osteopontin (OPN) is a significant chemoattractant in MSC migration to bone remodeling sites. The objective of this study was to determine whether the primary cilium acts as a chemoattractant sensory unit to detect OPN cues and control MSC migration. We found that the loss of primary cilium induced by silencing of IFT88 reduced OPN-induced migration of MSCs. The effect of IFT88 silencing on cellular attachment, spreading, and proliferation was negligible. The loss of primary cilium did not affect the level of integrinß1 or CD44, two known receptors for OPN. Interestingly, CD44 was localized to the primary cilium by OPN stimulus. Knockdown of IFT88 or CD44 dysregulated OPN-induced signaling activation and abolished OPN-induced Cdc42 activation. Our findings suggest that the primary cilium acts as a chemoattractant sensor for OPN to regulate MSC migration by controlling not only CD44-mediated OPN signaling, but also Cdc42-mediated actin cytoskeleton rearrangement.

Effects of Chin-Down Maneuver on Pharyngeal Pressure Generation According to Dysphagia and Viscosity.

OBJECTIVE: To demonstrate the effects of chin-down maneuver on swallowing by using high-resolution manometry (HRM). METHODS: HRM data of 20 healthy subjects and 64 dysphagic patients were analyzed. Participants swallowed 5 mL of thin and honey-like liquids in neutral and chin-down positions. HRM was used to evaluate maximal velopharyngeal pressure/area, maximal tongue base pressure/area, maximal pharyngeal constrictor pressure, pre-/post-swallow upper esophageal sphincter (UES) peak pressure, minimal UES pressure, UES activity time, and nadir duration. RESULTS: Compared to the neutral position, the chin-down maneuver significantly increased tongue base pressure in both normal and dysphagic groups as well as for both honey-like and thin viscosities, although the honey-like liquid did not reach statistical significance in the dysphagic group. Regarding pharyngeal constrictors and pre-swallow peak UES pressure, the healthy group showed a significant decrease in thin liquid swallowing and decreasing tendency in honeylike liquid swallowing. UES nadir duration was significantly decreased for honey-like liquid swallowing in the dysphagic group and for both thin and honey-like liquids in the healthy group. UES nadir duration of honey-like and thin flow swallowing in the dysphagia group was 0.26 seconds after the chin-down maneuver, which was severely limited. CONCLUSION: This study showed a different kinetic effect of the chin-down maneuver between the healthy and dysphagic groups, as well as between thin and honey-like viscosities. The chin-down maneuver increased tongue base pressure and decreased UES nadir duration, which the latter was severely limited in dysphagic patients. Therefore, appropriate application of the chin-down maneuver in clinical practice is required.