Background: Stem cell therapy for the treatment of osteonecrosis of the femoral head (ONFH) showed promising outcomes. However, ONFH with a large lesion in the weight-bearing portion is a poor prognostic factor and still challenging issue to be solved. We aimed to evaluate the effect of tissue-engineered bone regeneration for this challenging condition to preserve the femoral head. Methods: A total of 7 patients (9 hips) with ONFH who received osteoblasts expanded ex vivo from bone marrow-derived mesenchymal stem cells (BMdMSCs) and calcium metaphosphate (CMP) as scaffolds from March 2002 to March 2004 were retrospectively reviewed. The median age was 27.0 years (interquartile range [IQR], 23.0–34.0 years), and the median follow-up period was 20.0 years (IQR, 11.0–20.0 years). After culture and expansion of stem cells, we performed core decompression with BMdMSC implantation at a median number of 10.1 ×107 (IQR, 9.9–10.9 ×107 ). To evaluate radiographic outcomes, the Association Research Circulation Osseous (ARCO) classifications, the Japanese Investigation Committee (JIC) classification, and modified Kerboul combined necrotic angle (mKCNA) were evaluated preoperatively and during follow-up. Clinical outcomes were evaluated by a visual analog scale (VAS) and Harris Hip Score (HHS). Results: The preoperative stage of ONFH was ARCO 2 in 5 hips and ARCO 3a in 4 hips. The ARCO staging was maintained in 3 hips of ARCO 2 and 4 hips of ARCO 3a. Two hips of ARCO 2 with radiographic progression underwent total hip arthroplasty. According to mKCNA, 2 hips showed medium lesions, and 7 hips showed large lesions. The size of necrotic lesion was decreased in 4 hips (2 were ARCO 2 and 2 were ARCO 3a). There were no significant changes in JIC classification in all hips (type C1: 3 hips and type C2: 6 hips) (p = 0.655). Clinically, there were no significant changes in the VAS and HHS between preoperative and last followup (p = 0.072 and p = 0.635, respectively). Conclusions Tissue engineering technique using osteoblasts expanded ex vivo from BMdMSC and CMP showed promising outcomes for the treatment of pre-collapsed and early-collapsed stage ONFH with medium-to-large size, mainly located in weightbearing areas.

Background: Inter-hospital transfers of severely injured patients are inevitable due to limited resources. We investigated the association between inter-hospital transfer and the prognosis of pediatric injury using the Korean multi-institutional injury registry. Methods: This retrospective observational study was conducted from January 2013 to December 2017; data for hospitalized subjects aged < 18 years were extracted from the Emergency Department-based Injury in Depth Surveillance database, in which 22 hospitals are participating as of 2022. The survival rates of the direct transfer group and the interhospital transfer group were compared, and risk factors affecting 30-day mortality and 72-hour mortality were analyzed. Results: The total number of study subjects was 18,518, and the transfer rate between hospitals was 14.5%. The overall mortality rate was 2.3% (n = 422), the 72-hour mortality was 1.7% (n = 315) and the 30-day mortality rate was 2.2% (n = 407). The Kaplan-Meier survival curve revealed a lower survival rate in the inter-hospital transfer group than in the direct visit group (log-rank, P < 0.001). Cox proportional hazards regression analysis showed that interhospital transfer group had a higher 30-day mortality rate and 72-hour mortality (hazard ratio [HR], 1.681; 95% confidence interval [CI], 1.232–2.294 and HR, 1.951; 95% CI, 1.299–2.930) than direct visit group when adjusting for age, sex, injury severity, and head injury. Conclusion Among the pediatric injured patients requiring hospitalization, inter-hospital transfer in the emergency department was associated with the 30-day mortality rate and 72-hour mortality rate in Korea.

Purpose: This study was performed to identify risk factors associated with post-tonsillectomy hemorrhage (PTH)-related hospitalization in pediatric patients visiting an emergency department (ED). Methods: We retrospectively reviewed the medical records of patients who underwent tonsillectomy at a single children’s hospital ED from January 2009 through December 2020. Data were collected on patient demographics, chief complaints, surgical methods, postoperative days, initial vital signs, and laboratory findings. The study population was divided into hospitalized and discharged groups. Results: Among a total of 2,716 patients reviewed, 67 met the inclusion criteria. The hospitalized group showed a lower median systolic blood pressure (108.0 [interquartile range, 82.0-134.0] vs. 118.5 [89.8-147.2] mmHg; P = 0.021) and a faster median respiratory rate (23.0 [18.0-28.0] vs. 20.0 [17.0-23.0] breaths/minute; P = 0.019), compared with the discharged group. Multivariable logistic regression identified systolic blood pressure under 100 mmHg (odds ratio, 5.21; 95% confidence interval, 1.17-37.60) and respiratory rate over 24 breaths/minute (7.31; 1.07-145.79) as the factors associated with PTH-related hospitalization. Conclusion When pediatric patients visit EDs for PTH, close monitoring or hospitalization may be needed in those with low systolic blood pressure or rapid respiratory rate.

BACKGROUND: Inflammatory bowel disease (IBD) is an incurable disease that negatively influences the quality of life of patients. Current and emerging therapies target proinflammatory cytokines and/or receptors to downregulate proinflammatory responses, but insufficient remission requires other therapeutic agents. Herein, we report that the synthetic antiinflammatory peptide 15 (SAP15) is capable of cell penetration and anti-inflammatory activity in human macrophages. METHODS: SAP15 was labeled with fluorescence and administered to human leukemia monocytic cells (THP-1) cells for cell penetration analysis. Using biolayer interferometry analysis, the binding affinity of SAP15 with histone deacetylase 5 (HDAC5) was measured. SAP15-treated THP-1 cells were analyzed by protein phosphorylation assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). In addition, in vivo analysis of the therapeutic effect on IBD was observed in a dextran sulfate sodium (DSS)-induced model. Samples from SAP15-treated mice were analyzed at both the macroscopic and microscopic levels using ELISA, myeloperoxidase (MPO) assays, and histological evaluations. RESULTS: SAP15 was internalized within the cytosol and nucleus of THP-1 cells and bound to the HDAC5 protein. SAP15-treated macrophages were assessed for protein phosphorylation and showed inhibited phosphorylation of HDAC5 and other immune-related proteins, which led to increased M2-like macrophage markers and decreased M1-like macrophage markers and tumor necrosis factor-a and interleukin-6 cytokine levels. The SAP15 treatment on IBD model showed significant recovery of colon length. Further histological analysis of colon demonstrated the therapeutic effect of SAP15 on mucosal layer. Moreover, proinflammatory cytokine levels and MPO activity from the plasma show that SAP15 is effective in reduced proinflammatory responses. CONCLUSION These findings suggest that SAP15 is a novel peptide with a novel cell-penetrating peptide with antiinflammatory property that can be used as a therapeutic agent for IBD and other inflammatory diseases.

BACKGROUND: Bone growth factors, particularly bone morphogenic protein-2 (BMP-2), are required for effective treatment of significant bone loss. Despite the extensive development of bone substitutes, much remains to be desired for wider application in clinical settings. The currently available bone substitutes cannot sustain prolonged BMP-2 release and are inconvenient to use. In this study, we developed a ready-to-use bone substitute by sequential conjugation of BMP to a three-dimensional (3D) poly(L-lactide) (PLLA) scaffold using novel molecular adhesive materials that reduced the operation time and sustained prolonged BMP release. METHODS: A 3D PLLA scaffold was printed and BMP-2 was conjugated with alginate-catechol and collagen. PLLA scaffolds were conjugated with different concentrations of BMP-2 and evaluated for bone regeneration in vitro and in vivo using a mouse calvarial model. The BMP-2 release kinetics were analyzed using ELISA. Histological analysis and microCT image analysis were performed to evaluate new bone formation. RESULTS: The 3D structure of the PLLA scaffold had a pore size of 400 lm and grid thickness of 187–230 lm. BMP-2 was released in an initial burst, followed by a sustained release for 14 days. Released BMP-2 maintained osteoinductivity in vitro and in vivo. Micro-computed tomography and histological findings demonstrate that the PLLA scaffold conjugated with 2 lg/ml of BMP-2 induced optimal bone regeneration. CONCLUSION The 3D-printed PLLA scaffold conjugated with BMP-2 enhanced bone regeneration, demonstrating its potential as a novel bone substitute.

BACKGROUND: The neural regulation of bone regeneration has emerged recently. Spexin (SPX) is a novel neuropeptide and regulates multiple biological functions. However, the effects of SPX on osteogenic differentiation need to be further investigated. Therefore, the aim of this study is to investigate the effects of SPX on osteogenic differentiation, possible underlying mechanisms, and bone regeneration. METHODS: In this study, MC3T3-E1 cells were treated with various concentrations of SPX. Cell proliferation, osteogenic differentiation marker expressions, alkaline phosphatase (ALP) activity, and mineralization were evaluated using the CCK-8 assay, reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), ALP staining, and alizarin red S staining, respectively. To determine the underlying molecular mechanism of SPX, the phosphorylation levels of signaling molecules were examined via western blot analysis. Moreover, in vivo bone regeneration by SPX (0.5 and 1 lg/ll) was evaluated in a calvarial defect model. New bone formation was analyzed using micro-computed tomography (micro-CT) and histology. RESULTS: The results indicated that cell proliferation was not affected by SPX. However, SPX significantly increased ALP activity, mineralization, and the expression of genes for osteogenic differentiation markers, including runt-related transcription factor 2 (Runx2), Alp, collagen alpha-1(I) chain (Col1a1), osteocalcin (Oc), and bone sialoprotein (Bsp). In contrast, SPX downregulated the expression of ectonucleotide pyrophosphatase/phosphodiesterase 1 (Enpp1). Moreover, SPX upregulated phosphorylated mitogen-activated protein kinase kinase (MEK1/2) and extracellular signal-regulated kinase (ERK1/2). in vivo studies, micro-CT and histologic analysis revealed that SPX markedly increased a new bone formation. CONCLUSION Overall, these results demonstrated that SPX stimulated osteogenic differentiation in vitro and increased in vivo bone regeneration via the MEK/ERK pathway.

BACKGROUND/OBJECTIVES: Isoflavones (ISFs) are effective in preventing bone loss, but not effective enough to prevent osteoporosis. Mixtures of soy ISF and lecithin (LCT) were prepared and characterized in an attempt to improve the bone loss.MATERIALS/METHODS: The daidzein (DZ) and genistein (GN) solubility in soy ISF were measured using liquid chromatography-mass spectrometry. The change in the crystalline characteristics of soy ISF in LCT was evaluated using X-ray diffraction analysis.Pharmacokinetic studies were conducted to evaluate and compare ISF bioavailability. Animal studies with ovariectomized (OVX) mice were carried out to estimate the effects on bone loss. The Student's t-test was used to evaluate statistical significance. RESULTS: The solubility of DZ and GN in LCT was 125.6 and 9.7 mg/L, respectively, which were approximately 25 and 7 times higher, respectively, than those in water. The bioavailability determined by the area under the curve of DZ for the oral administration (400 mg/kg) of soy ISF alone and the soy ISF-LCT mixture was 13.19 and 16.09 µg·h/mL, respectively. The bone mineral density of OVX mice given soy ISF-LCT mixtures at ISF doses of 60 and 100 mg/kg daily was 0.189 ± 0.020 and 0.194 ± 0.010 g/mm3 , respectively, whereas that of mice given 100 mg/kg soy ISF was 0.172 ± 0.028 g/mm3 . The number of osteoclasts per bone perimeter was reduced by the simultaneous administration of soy ISF and LCT. CONCLUSIONS The effect of preventing bone loss and osteoclast formation by ingesting soy ISF and LCT at the same time was superior to soy ISF alone as the bioavailability of ISF may have been improved by the emulsification and solvation of LCT. These results suggest the possibility of using the combination of soy ISF and LCT to prevent osteoporosis.

BACKGROUND: This study investigates the effects of a neuropeptide, secretoneurin (SN), on bone regeneration in an experimental mouse model. METHODS: The effects of SN on cell proliferation, osteoblast marker genes expression, and mineralization were evaluated using the CCK-8 assay, quantitative reverse transcriptase polymerase chain reaction (RT-PCR), and alizarin red S staining, respectively. To examine the effects of SN on bone regeneration in vivo, bone defects were created in the calvaria of ICR mice, and 0.5 or 1 lg/ml SN was applied. New bone formation was analyzed by micro-computed tomography (micro-CT) and histology. New blood vessel formation was assessed by CD34 immunohistochemistry. RESULTS: SN had no significant effect on proliferation and mineralization of MC3T3-E1 cells. However, SN partially induced the gene expression of osteoblast differentiation markers such as runt-related transcription factor 2, alkaline phosphatase, collagen type I alpha 1, and osteopontin. A significant increase of bone regeneration was observed in SN treated calvarial defects. The bone volume (BV), BV/tissue volume, trabecular thickness and trabecular number values were significantly increased in the collagen sponge plus 0.5 or 1 lg/ml SN group (p < 0.01) compared with the control group. Histologic analysis also revealed increased new bone formation in the SN-treated groups. Immunohistochemical staining of CD34 showed that the SN-treated groups contained more blood vessels compared with control in the calvarial defect area. CONCLUSION SN increases new bone and blood vessel formation in a calvarial defect site. This study suggests that SN may enhance new bone formation through its potent angiogenic activity.

BACKGROUND/OBJECTIVES: Isoflavones (ISFs) are effective in preventing bone loss, but not effective enough to prevent osteoporosis. Mixtures of soy ISF and lecithin (LCT) were prepared and characterized in an attempt to improve the bone loss.MATERIALS/METHODS: The daidzein (DZ) and genistein (GN) solubility in soy ISF were measured using liquid chromatography-mass spectrometry. The change in the crystalline characteristics of soy ISF in LCT was evaluated using X-ray diffraction analysis.Pharmacokinetic studies were conducted to evaluate and compare ISF bioavailability. Animal studies with ovariectomized (OVX) mice were carried out to estimate the effects on bone loss. The Student's t-test was used to evaluate statistical significance. RESULTS: The solubility of DZ and GN in LCT was 125.6 and 9.7 mg/L, respectively, which were approximately 25 and 7 times higher, respectively, than those in water. The bioavailability determined by the area under the curve of DZ for the oral administration (400 mg/kg) of soy ISF alone and the soy ISF-LCT mixture was 13.19 and 16.09 µg·h/mL, respectively. The bone mineral density of OVX mice given soy ISF-LCT mixtures at ISF doses of 60 and 100 mg/kg daily was 0.189 ± 0.020 and 0.194 ± 0.010 g/mm3 , respectively, whereas that of mice given 100 mg/kg soy ISF was 0.172 ± 0.028 g/mm3 . The number of osteoclasts per bone perimeter was reduced by the simultaneous administration of soy ISF and LCT. CONCLUSIONS The effect of preventing bone loss and osteoclast formation by ingesting soy ISF and LCT at the same time was superior to soy ISF alone as the bioavailability of ISF may have been improved by the emulsification and solvation of LCT. These results suggest the possibility of using the combination of soy ISF and LCT to prevent osteoporosis.