Instrumentation failure following pediatric spine deformity growth-sparing surgery using traditional growing rods or vertical expandable prosthetic titanium ribs.

BACKGROUND: Instrumentation failure (IF) is a major complication associated with growth-sparing surgery for pediatric spinal deformities; however, studies focusing on IF following each surgical procedure are lacking. We aimed to evaluate the incidence, timing, and rates of unplanned return to the operating room (UPROR) associated with IF following each surgical procedure in growth-sparing surgeries using traditional growing rods (TGRs) and vertical expandable prosthetic titanium ribs (VEPTRs). METHODS: We reviewed 1,139 surgical procedures documented in a Japanese multicenter database from 2015 to 2017. Of these, 544 TGR and 455 VEPTR procedures were included for evaluation on a per-surgery basis. IF was defined as the occurrence of an implant-related complication requiring revision surgery. RESULTS: The surgery-based incidences of IF requiring revision surgery in the TGR and VEPTR groups were 4.3% and 4.0%, respectively, with no significant intergroup difference. Remarkably, there was a negative correlation between IF incidence per surgical procedure and the number of lengthening surgeries in both groups. In addition, rod breakage in the TGR group and anchor-related complications in the VEPTR group tended to occur relatively early in the treatment course. The surgery-based rates of UPROR due to IF in the TGR and VEPTR groups were 2.0% and 1.5%, respectively, showing no statistically significant difference. CONCLUSIONS: We found that IF, such as anchor related-complications and rod breakage, occurs more frequently earlier in the course of lengthening surgeries. This finding may help in patient counseling and highlights the importance of close postoperative follow-up to detect IF and improve outcomes.

Theoretical and experimental mechanistic study of water molecule involvement in the Prilezhaev reaction.

The Prilezhaev reaction produces epoxides using alkenes and peroxy acids such as m-chloroperoxybenzoic acid (mCPBA). The reaction proceeds via a concerted mechanism in one step. Although the mCPBA used in organic syntheses contains water because of its explosive nature, the effects of water on the reaction have not been considered. To investigate the effects of water on the reaction mechanism, we determined the thermodynamic parameters for the Prilezhaev reaction between styrene and mCPBA. The activation free energies, including solvent effects, were calculated using the SMD and QM/MC/FEP methods. The calculated thermodynamic parameters for the reaction directly involving two water molecules were in better agreement with the experimental data than those for the concerted mechanism. This result indicated that water molecules are involved in the progression of the mCPBA-mediated Prilezhaev reaction in solvents containing water molecules.

Does Flexion Varus Osteotomy Improve Radiographic Findings Compared With Patients Treated in a Brace for Late-onset Legg-Calvé-Perthes Disease?

BACKGROUND: Legg-Calvé-Perthes disease (LCPD) is a childhood hip disease characterized by osteonecrosis of the femoral head. Because severe deformity of the femoral head can cause secondary osteoarthritis in adulthood, progressive collapse should be prevented in children with a necrotic epiphysis. The prognosis of patients with LCPD generally worsens as the age at disease onset increases, and the appropriate treatment for late-onset LCPD remains unclear. Based on the limited effect of nonoperative treatment using a nonweightbearing brace, flexion varus osteotomy (FVO) was introduced in 2010 as an initial treatment for late-onset LCPD in place of brace treatment, which we used in our institution before that time. QUESTIONS/PURPOSES: We asked, (1) Which treatment, FVO or a nonweightbearing brace, is associated with a lower likelihood of progressive femoral head collapse in children whose diagnosis of LCPD was made at the age of ≥ 8 years and who were followed for a minimum of 3 years after their intervention? (2) What proportion of patients in the brace group had surgery despite the treatment, and what percentage of children in the FVO group had a second operation to remove hardware and/or additional operations? METHODS: The initial treatment was applied in 181 patients with LCPD between 1995 and 2018 in our institution. Patients whose disease onset was at ≥ 8 years old (late-onset LCPD) with complete clinical and radiologic data were considered potentially eligible. In 2010, treatment for these patients changed from brace treatment to FVO for all patients. A total of 35% (42 of 121) of patients who were treated with a nonweightbearing brace between 1995 and 2009 and 40% (24 of 60) of patients who were treated with FVO between 2010 and 2018 were eligible. Among patients treated with a brace, 21% (nine of 42 patients) were excluded because of hospital transfer (three patients), short-term follow-up (three), the period from onset to the first visit was ≥ 7 months (two), and inability to use the brace because of mental incapacity (one patient). In patients treated with FVO, 12% (three of 24 patients) were excluded (two patients with a period from onset to the first visit ≥ 7 months and one with a comorbidity and multiple-epiphyseal dysplasia). Among the remaining patients, 79% (33 of 42 patients) were classified into the brace group and 88% (21 of 24 patients) were classified into the FVO group for analyses. There were no overlapping patients at the timepoint when the treatment strategy for late-onset LCPD changed. In the FVO group, subtrochanteric osteotomy with 35° to 40° of flexion and 15° to 20° of varus was performed using a locking compression plate for pediatric use. Patient demographics, radiographic parameters, and the assessment of femoral head deformity using the Stulberg classification were compared between the two groups. There was a greater proportion of boys than girls in both groups (brace: 88% and FVO: 86%), and there were no differences in the distribution of genders between the groups (p = 0.82). The right side was more frequently treated in the brace group, but there was no difference in laterality between the groups (brace: 58% right and FVO: 62% left; p = 0.16). There was no difference between groups in the median age at disease onset (9.0 years [range 8.0 to 12.5 years] in the brace group and 9.6 years [range 8.0 to 12.4 years] in the FVO group; p = 0.26). There was no difference between the groups in the period of treatment from onset (1.7 ± 1.9 months in the brace group and 1.5 ± 1.5 months in the FVO group; p = 0.73) or the follow-up period (6.7 ± 2.1 years in the brace group and 6.2 ± 2.1 years in the FVO group; p = 0.41). The LCPD stage at the first visit was assessed using the modified Waldenström classification. The intraobserver and interobserver values of the modified Waldenström classification, evaluated using kappa statistics, were excellent (kappa value 0.89 [95% CI 0.75 to 0.97]; p < 0.01) and good (kappa value 0.65 [95% CI 0.43 to 0.87]; p < 0.01). The radiographic degree of collapse at the maximum fragmentation stage was assessed using the lateral pillar classification. The intraobserver and interobserver reliabilities of the lateral pillar classification were excellent (kappa value 0.84 [95% CI 0.73 to 0.94]; p < 0.01) and excellent (kappa value 0.83 [95% CI 0.71 to 0.94]; p < 0.01). The degree of femoral head deformity at the most recent follow-up examination was compared between the groups in terms of the Stulberg classification, in which Classes I and II were classified as good and Classes III through V were classified as poor. The intraobserver and interobserver reliabilities of the Stulberg classification were good (kappa value 0.74 [95% CI 0.55 to 0.92]; p < 0.01) and good (kappa value 0.69 [95% CI 0.50 to 0.89]; p < 0.01). The evaluators were involved in the patients' clinical care as part of the treating team. RESULTS: Good radiographic results (Stulberg Class I or II) were obtained more frequently in the FVO group (76% [16 of 21 patients]) than in the brace group (36% [12 of 33 patients]), with an odds ratio of 5.6 (95% CI 1.7 to 18.5; p < 0.01). In the brace group, a subsequent femoral varus osteotomy was performed in 18% (six of 33) of patients with progressive collapse and hinge abduction, and implant removal surgery was performed approximately 1 year after the first procedure. This traditional varus osteotomy was occasionally performed in patients who were considered for conversion from nonoperative treatment before 2009 because FVO had not yet been introduced. In the FVO group, all patients (n = 21) had a second procedure to remove the implant at a mean of 10.5 ± 1.2 months postoperatively. Additional procedures were performed in 24% (five of 21) of patients, including a second FVO for progressive collapse (one patient), guided growth for a limb length discrepancy (one patient), and flexion valgus osteotomy for coxa vara in patients with a limb length discrepancy (three patients). CONCLUSION: Our historical control study found that FVO may increase the possibility of obtaining good radiographic results (Stulberg Class I or II) compared with brace treatment for patients with late-onset LCPD, although surgical interventions after the first and second implant removal procedures may be indicated. Surgeons can consider FVO if they encounter patients with late-onset LCPD, which is a challenging condition. A larger study with long-term follow-up is needed to confirm the efficacy of FVO. LEVEL OF EVIDENCE: Level III, therapeutic study.

A Novel Method for Assessing the 3-dimensional Morphology of Cartilaginous Acetabulum Via Childhood Magnetic Resonance Imaging.

BACKGROUND: Periarticular cartilage is abundant in children, making evaluations of 3-dimensional (D) cartilaginous acetabular morphology using x-ray or computed tomography (CT) difficult. The study aimed to visualize the 3D cartilaginous acetabular morphology in normal children and patients with pediatric developmental dysplasia of the hip (DDH). METHODS: Magnetic resonance imaging (MRI) of 17 female children without acetabular dysplasia at 7.5 years and CT of 33 normal female adolescents with mature bones at 14.6 years were used as controls. Subjects were 26 female patients with unilateral DDH who underwent angulated Salter innominate osteotomy (A-SIO) at 5.5 years. Preoperative and postoperative MRIs were performed at 5.2 and 7.0 years, respectively. The MRI sequence was 3D-MEDIC. The medial intersection (point A) of the line connecting the centers of the bilateral femoral head and the femoral head were defined as point zero. The 3D coordinates (X, Y, Z) of the cartilaginous acetabular edge (point C) from anterior to posterior were calculated. Subsequently, a 3D scatter plot was created using 3D graph software. The subjects were divided into 6 groups, including control MRI, control CT, unaffected DDH before and after A-SIO, and affected DDH before and after A-SIO. The femoral head coverage ratio (FHCR: AC/AB) was used to quantify coverage and was compared in each group. RESULTS: In the control MRI group, the acetabular coverage was small anteriorly, largest anterolaterally, and gradually decreased posteriorly, similar to the bony acetabulum in adolescents. In the affected DDH before A-SIO group, the coverage was significantly lower than that of the control MRI and unaffected DDH groups. After A-SIO, the morphology improved beyond the unaffected DDH and the control MRI group. CONCLUSIONS: The global defect of the cartilaginous acetabulum in the affected DDH group was significantly improved to normal morphology after A-SIO. Evaluating the cartilaginous acetabulum using MRI was useful for assessing hip morphology in childhood. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Hip Prognosis in Patients With Congenital Diastasis of the Pubic Symphysis.

BACKGROUND: Congenital diastasis of the pubic symphysis (CDPS) is a rare musculoskeletal malformation in the exstrophy-epispadias complex that is potentially associated with the development of hip dysplasia. The purpose of this study was to investigate the incidence and prognostic factors of hip dysplasia in patients with CDPS. METHODS: Fifty-four hips in 27 patients with CDPS initially evaluated between 1983 and 2016 were retrospectively reviewed. The mean age at the first visit was 2.3 (0 to 8) years. The mean follow-up duration was 10.5 (1 to 36) years. Patient characteristics at the first visit, the clinical course at the most recent follow-up, and radiologic parameters on pubic malformation and hip dysplasia during at least 2 time points (first visit or age 1, and either the most recent visit or before hip surgery) were evaluated. Prognostic factors associated with the development of hip dysplasia were analyzed using univariate/multivariate analysis. The Kaplan-Meier survival curves were generated and compared based on these factors. RESULTS: Nine of 27 patients (33%) and 13 of 54 hip joints (24%) with CDPS developed hip dysplasia. Paraplegia (odds ratio, 10.0; 95% confidence interval, 1.7-76.6) and center-edge angle of <5 degrees at the first visit or age 1 (P<0.001) were independent predictors of the development of hip dysplasia. Patients with CDPS and either paraplegia or center-edge angle <5 degrees at the first visit or age 1 were significantly more likely to develop hip dysplasia than other patients (hazard ratio, 29.3; 95% confidence interval, 3.4-250). CONCLUSIONS: Approximately one third of patients with CDPS develop hip dysplasia. Paraplegia and center-edge angle of <5 degrees at the first visit are independent risk factors. LEVEL OF EVIDENCE: Level III.

Hyperpolarized 13 C Magnetic Resonance Imaging of Fumarate Metabolism by Parahydrogen-induced Polarization: A Proof-of-Concept in†vivo Study.

The front cover artwork is provided by the group of Dr. Neil J. Stewart, Prof. Hiroshi Hirata, and Dr. Shingo Matsumoto (Hokkaido University, Japan) as well as Dr. Takuya Hashimoto (Chiba University, Japan). The image shows hyperpolarized 13 C fumarate metabolism to hyperpolarized 13 C malate, which is released into the extracellular space in regions of necrotic cell death, where the cell membrane is disrupted. Read the full text of the Article at 10.1002/cphc.202001038.

Hyperpolarized 13 C Magnetic Resonance Imaging of Fumarate Metabolism by Parahydrogen-induced Polarization: A Proof-of-Concept in†vivo Study.

Hyperpolarized [1-13 C]fumarate is a promising magnetic resonance imaging (MRI) biomarker for cellular necrosis, which plays an important role in various disease and cancerous pathological processes. To demonstrate the feasibility of MRI of [1-13 C]fumarate metabolism using parahydrogen-induced polarization (PHIP), a low-cost alternative to dissolution dynamic nuclear polarization (dDNP), a cost-effective and high-yield synthetic pathway of hydrogenation precursor [1-13 C]acetylenedicarboxylate (ADC) was developed. The trans-selectivity of the hydrogenation reaction of ADC using a ruthenium-based catalyst was elucidated employing density functional theory (DFT) simulations. A simple PHIP set-up was used to generate hyperpolarized [1-13 C]fumarate at sufficient 13 C polarization for ex vivo detection of hyperpolarized 13 C malate metabolized from fumarate in murine liver tissue homogenates, and in vivo 13 C MR spectroscopy and imaging in a murine model of acetaminophen-induced hepatitis.

A longitudinal study for the prediction of the mature acetabular morphology using childhood magnetic resonance imaging.

BACKGROUND: Although acetabular dysplasia is a common etiology of osteoarthritis of the hip regardless of the history of developmental dysplasia of the hip (DDH), whether or not corrective surgeries are beneficial for the childhood asymptomatic acetabular dysplasia remains controversial due to a lack of evidence. We conducted a longitudinal study to compare the cartilaginous morphology on childhood magnetic resonance imaging (MRI) and the mature hip morphology of the same patient and to assess the predictive indicators for future acetabular dysplasia. METHODS: A total of 92 unaffected hips (47 unilateral DDH and 45 unilateral Legg-Calvé-Perthes disease) were reviewed for X-ray and MRI findings on childhood (mean age: 6.0 years) and X-ray findings from a skeletally mature age with a mean follow-up period of 15.1 years. The following parameters were measured and compared: the immature-acetabular index (AI) and center edge angle (CE) on immature X-ray; the cartilage- and bone- AI, CE, Sharp and acetabular head index (AHI) on childhood MRI; and the mature-acetabular roof obliquity (ARO), CE, Sharp and AHI on skeletally mature X-ray. The prognostic factors on childhood MRI for acetabular dysplasia, defined by a CE of <20° on skeletally mature X-ray were also assessed. RESULTS: Positive correlations were shown between the cartilage-AI and mature-ARO (7.6°/6.3°; r = 0.44), the cartilage-CE and mature-CE (27.8°/28.0°; r = 0.62), the cartilage-Sharp and mature-Sharp (44.4°/41.8°; r = 0.52) and the cartilage-AHI and mature-AHI (78.7%/80.3%; r = 0.46). A multivariate analysis indicated cartilage-CE to be an independent predictor for acetabular dysplasia with a cut-off value of 22°. Children with a cartilage-CE <22° developed more frequently acetabular dysplasia compared to the others (52.4% vs. 1.4%). CONCLUSIONS: Childhood MRI findings are useful for the prediction of acetabular dysplasia without a DDH history. Children with a cartilage-CE ≥23° are likely to achieve a non-dysplastic hip without the need for surgical intervention.

Terminal syringomyelia associated with lumbar limited dorsal myeloschisis.

PURPOSE: Limited dorsal myeloschisis (LDM) is characterized by a fibroneural tethering stalk linking the skin lesion to the underlying spinal cord. Terminal syringomyelia, which is located at the lower third of the cord, is often associated with a tethered cord caused by various spinal dysraphisms; however, terminal syringomyelia has not been documented in LDM. The purpose of this study was to clarify the pathophysiological mechanisms of syringomyelia in LDM. METHODS: In our 16 patients with lumbar LDM, three patients had terminal syringomyelia. We retrospectively analyzed the clinical, neuroradiological, intraoperative, and histopathological findings for these patients, with particular attention to the clinical course of the syrinx. RESULTS: Patient 1 had a saccular skin lesion and patients 2 and 3 had flat lesions. In all patients, the syringomyelic cavity was located in the lower thoracolumbar cord, immediately rostral to the stalk-cord attachment at the lumbar level. The caudal pole of the syrinx extended to the thickened stalk at the attachment instead of at the caudal cord. Patient 3 had another syrinx in the stalk itself. The longitudinal axis of the syrinx and central canal coincided with the traveling angle of the LDM stalk at the stalk-cord attachment. In patient 1, histology revealed an ependyma-lined central canal in both the LDM stalk and meningocele sac. Patients 1 and 2 underwent syringostomy, but long-term effects were not obtained. Preoperative spontaneous resolution occurred in patient 3. CONCLUSIONS: The histological findings in patient 1 supported the idea that segmental myelocystocele is involved in the development of saccular LDM. The hydromyelic central canal herniates and distends the stalk, resulting in the formation of the myelocystocele. It is possible that the hydromyelic central canal also distends the stalk of flat LDM lesions. The syrinx in patient 3 differed from that in patients 1 and 2, in that the syrinx resolved spontaneously. Further studies are needed to clarify the outcomes of syrinxes associated with LDM stalks.

Comparison of Early Definitive Fusion and Traditional Growing Rods in Early-onset Dystrophic Scoliosis in Neurofibromatosis Type 1: A Preliminary Report.

BACKGROUND: Early definitive spinal fusion (EF) has been widely recommended to avoid spinal deformity progression for early-onset scoliosis (EOS) with neurofibromatosis type 1 (NF-1). In contrast, growing rod (GR) procedure has recently been recommended for EOS associated with the dystrophic type NF-1. However, no studies have compared the surgical outcomes between EF and GR procedure for EOS with NF-1. The purpose of this study was to compare the surgical outcomes of EF versus GR for early onset and dystrophic scoliosis with NF-1. METHODS: This was a retrospective multicenter study; 26 EOS patients with dystrophic type of NF-1 who underwent EF (16 patients) or GR (10 patients) were investigated. We compared age at first surgery, fused levels, total number of surgeries, coronal major curve, complication rates, spinal height (T1-T12 and T1-S1 length), and forced vital capacity between the 2 groups. RESULTS: The mean age at first surgery was 7.3 years in the EF and 5.8 years in the GR (P<0.05). The mean follow-up period was 12.8 and 10.5 years, respectively. The 2 groups did not show significant differences in preoperative major Cobb angle (75.1 vs. 83.1 degrees), complication rate (53% vs. 60%), and increase rate of T1-T12 (20.0% vs. 30.4%). However, significant differences (P<0.05) were recognized in fusion segments (13.9 vs. 15.8), total numbers of surgery (2.6 vs. 10.1), correction rate of major curve (59.0% vs. 40.6%), increase rate of T1-S1 (19.0% vs. 33.9%), body height at final follow-up (151 vs. 142 cm), and forced vital capacity at final follow-up (2.23 vs. 1.46 L). CONCLUSIONS: Early fusion is still a viable option for progressive EOS with dystrophic type of NF-1 even in the growth-friendly era. Surgeons should consider the best procedure for each patient taking into account the severity of dystrophic change when treating EOS with NF-1. LEVEL OF EVIDENCE: Level IV.

Gold Nanoparticles Coimmobilized with Small Molecule Toll-Like Receptor 7 Ligand and α-Mannose as Adjuvants.

Adjuvants enhance the immune response during vaccination. Among FDA-approved adjuvants, aluminum salts are most commonly used in vaccines. Although aluminum salts enhance humoral immunity, they show a limited effect for cell-mediated immune responses. Thus, further development of adjuvants that induce T-cell-mediated immune response is needed. Toll-like receptors (TLRs) recognizing specific pathogen-associated molecular patterns activate innate immunity, which is crucial to shape adaptive immunity. Using TLR ligands as novel adjuvants in vaccines has therefore attracted substantial attention. Among them a small molecule TLR7 ligand, imiquimod, has been approved for clinical use, but its use is restricted to local administration due to unwanted adverse side effects when used systematically. Since TLR7 is mainly located in the endosomal compartment of immune cells, efficient transport of the ligand into the cells is important for improving the potency of the TLR7 ligand. In this study we examined gold nanoparticles (GNPs) immobilized with α-mannose as carriers for a TLR7 ligand to target immune cells. The small molecule synthetic TLR7 ligand, 2-methoxyethoxy-8-oxo-9-(4-carboxy benzyl)adenine (1V209), and α-mannose were coimmobilized via linker molecules consisting of thioctic acid on the GNP surface (1V209-αMan-GNPs). The in vitro cytokine production activity of 1V209-αMan-GNPs was higher than that of the unconjugated 1V209 derivative in mouse bone marrow-derived dendritic cells and in human peripheral blood mononuclear cells. In the in vivo immunization study, 1V209-αMan-GNPs induced significantly higher titers of IgG2c antibody specific to ovalbumin as an antigen than did unconjugated 1V209, and splenomegaly and weight loss were not observed. These results indicate that 1V209-αMan-GNPs could be useful as safe and effective adjuvants for development of vaccines against infectious diseases and cancer.

Successful reduction of ACTH secretion in a case of intractable Cushing's disease with pituitary Crooke's cell adenoma by combined modality therapy including temozolomide.

Crooke's cell adenoma (CCA) is an aggressive subtype of corticotroph adenoma; however, CCA is associated with a high incidence of low expression of methyl guanine methyl transferase (MGMT), suggesting that temozolomide (TMZ) treatment might be effective for this tumor type. The case of a 56-year-old woman with Cushing's disease caused by a pituitary CCA is presented. At the age of 38 years, the patient presented to our hospital with polyuria and a visual field defect. MRI and laboratory studies showed a 4.5-cm-diameter pituitary tumor with plasma adrenocorticotropic hormone (ACTH) and serum cortisol levels of more than 500 pg/mL and 40 µg/dL, respectively. At 39 years of age, the patient underwent a craniotomy, and her plasma ACTH and cortisol levels decreased to less than 200 pg/mL and 10 µg/dL, respectively; however, these hormone levels increased gradually to 3,940 pg/mL and 70 µg/dL, respectively, by the time the patient was 56 years old. Histopathological re-examination of the previously resected specimen showed that the pituitary tumor was MGMT-negative CCA. TMZ treatment after the second operation decreased the plasma ACTH levels from 600-800 pg/mL to 70-300 pg/mL. No signs of recurrence were observed in the seven years following these treatments with added prophylactic radiation therapy. These clinical findings suggest that TMZ treatment to patients with CCA accompanied with elevated ACTH may be good indication to induce lowering ACTH levels and tumor shrinkage.

Advanced Glycation End Product 3 (AGE3) Increases Apoptosis and the Expression of Sclerostin by Stimulating TGF-ß Expression and Secretion in Osteocyte-Like MLO-Y4-A2 Cells.

Advanced glycation end products (AGEs) cause bone fragility due to deterioration in bone quality. We previously reported that AGE3 induced apoptosis and inhibited differentiation via increased transforming growth factor (TGF)-ß signaling in osteoblastic cells. Additionally, we demonstrated that AGE3 increased apoptosis and sclerostin expression and decreased receptor activator of nuclear factor-κB ligand (RANKL) expression in osteocyte-like cells. However, it remains unclear whether TGF-ß signaling is involved in the effects of AGEs on apoptosis and the expression of sclerostin and RANKL in osteocytes. Effects of AGE3 on apoptosis of mouse osteocyte-like MLO-Y4-A2 cells were examined by DNA fragmentation ELISA. Expression of TGF-ß, sclerostin, and RANKL was evaluated using real-time PCR, Western blotting, and ELISA kits. To block TGF-ß signaling, we used SD208, a TGF-ß type I receptor kinase inhibitor. AGE3 (200 µg/mL) significantly increased apoptosis and mRNA expression of Sost, the gene encoding sclerostin, and decreased Rankl mRNA expression in MLO-Y4-A2 cells. AGE3 significantly increased the expression of TGF-ß. Co-incubation of SD208 with AGE3 significantly rescued AGE3-induced apoptosis in a dose-dependent manner. Moreover, SD208 restored AGE3-increased mRNA and protein expression of sclerostin. In contrast, SD208 did not affect AGE3-decreased mRNA and protein expression of RANKL. These findings suggest that AGE3 increases apoptosis and sclerostin expression through increasing TGF-ß expression in osteocytes, and that AGE3 decreases RANKL expression independent of TGF-ß signaling.

Serum dipeptidyl peptidase-4 is associated with multiple vertebral fractures in type 2 diabetes mellitus.

OBJECTIVE: Patients with type 2 diabetes mellitus (T2DM) have a high risk of fracture although they have slightly higher bone mineral density (BMD). There is no evidence that dipeptidyl peptidase-4 (DPP-4) is involved in the bone fragility of the patients. The aim of this study was to investigate the association between serum DPP-4 levels and vertebral fractures (VFs) in men with T2DM. DESIGN: We conducted a cross-sectional study and investigated the relationships between serum DPP-4 levels vs BMD at lumbar spine, femoral neck and radius, bone turnover markers and presence of VFs in 204 Japanese male patients. RESULTS: Multiple regression analyses adjusted for confounders such as age, duration of diabetes, body mass index, serum creatinine, HbA1c, serum albumin, log(alanine transaminase), and log(C-reactive protein) showed that serum DPP-4 was positively associated with bone formation markers (bone-specific alkaline phosphatase and osteocalcin) as well as a bone resorption marker [tartrate-resistant acid phosphatase 5b (TRACP-5b)] (ß = 0·25, P < 0·01; ß = 0·17, P < 0·05; and ß = 0·30, P < 0·01, respectively), but not BMD at each site. Multivariate logistic regression analyses adjusted for the confounders described above revealed that serum DPP-4 levels were associated with the presence of multiple VFs (odds ratio 1·61, 95% confidential interval 1·05-2·49 per SD increase, P < 0·05). This association was still significant after additional adjustment for any sites of BMD or bone turnover markers except for TRACP-5b. CONCLUSIONS: We firstly showed that high level of serum DPP-4 is associated with prevalent multiple VFs independently of BMD and bone formation in men with T2DM.

Effects of high glucose and advanced glycation end products on the expressions of sclerostin and RANKL as well as apoptosis in osteocyte-like MLO-Y4-A2 cells.

In diabetes mellitus (DM), high glucose (HG) and advanced glycation end products (AGEs) are involved in bone quality deterioration. Osteocytes produce sclerostin and receptor activator of nuclear factor-кB ligand (RANKL) and regulate osteoblast and osteoclast function. However, whether HG or AGEs directly affect osteocytes and regulate sclerostin and RANKL production is unknown. Here, we examined the effects of HG, AGE2, and AGE3 on the expression of sclerostin and RANKL and on apoptosis in osteocyte-like MLO-Y4-A2 cells. Treatment of the cells with 22 mM glucose, 100 µg/mL either AGE2 or AGE3 significantly increased the expression of sclerostin protein and mRNA; however, both AGEs, but not glucose, significantly decreased the expression of RANKL protein and mRNA. Moreover, treatment of the cells with HG, AGE2, or AGE3 for 72 h induced significant apoptosis. These detrimental effects of HG, AGE2, and AGE3 on sclerostin and RANKL expressions and on apoptosis were antagonized by pretreatment of the cells with 10(-8) M human parathyroid hormone (PTH)-(1-34). Thus, HG and AGEs likely suppress bone formation by increasing sclerostin expression in osteocytes, whereas AGEs suppress bone resorption by decreasing RANKL expression. Together, these processes may cause low bone turnover in DM. In addition, HG and AGEs may cause cortical bone deterioration by inducing osteocyte apoptosis. PTH may effectively treat these pathological processes and improve osteocyte function.

Active vitamin D possesses beneficial effects on the interaction between muscle and bone.

Vitamin D deficiency and advanced glycation end products (AGEs) are suggested to be involved in the pathogenesis of osteoporosis and sarcopenia. However, the effects of vitamin D and AGEs on myogenesis and the interaction between muscle and bone remains still unclear. We previously showed that osteoglycin (OGN) is secreted from myoblasts and stimulates osteoblastic differentiation, suggesting that it plays important roles in the interaction between muscle and bone. The aim of this study is thus to examine the effects of vitamin D and AGEs on myoblastic differentiation of C2C12 cells and osteoblastic differentiation of osteoblastic MC3T3-E1 cells through OGN expression. 1α,25-dihydroxyvitamin D3 (1,25D) and eldecalcitol, an active vitamin D analog, induced the expression of MyoD, myogenin and OGN, and these effects were abolished by vitamin D receptor (VDR) suppression by siRNA in C2C12 cells. Moreover, conditioned medium from 1,25D-pretreated C2C12 cells stimulated the expression of type 1 collagen and alkaline phosphatase in MC3T3-E1 cells, compared to control medium from 1,25D-untreated C2C12 cells. In contrast, conditioned medium from VDR-suppressed and 1,25D-pretreated C2C12 cells showed no effects. AGE2 and AGE3 suppressed the expression of MyoD, myogenin and OGN in C2C12 cells. Moreover, 1,25D blunted the AGEs' effects. In conclusion, these findings showed for the first time that active vitamin D plays important roles in myogenesis and muscle-induced osteoblastogenesis through OGN expression. Active vitamin D treatment may rescue the AGEs-induced sarcopenia as well as - suppressed osteoblastic differentiation via OGN expression in myoblasts.

Involvement of the osteoinductive factors, Tmem119 and BMP-2, and the ER stress response PERK-eIF2α-ATF4 pathway in the commitment of myoblastic into osteoblastic cells.

The osteoinductive factors BMP-2 and Tmem119 that promote the differentiation of myoblasts into osteoblasts, each increase the levels of the other. However, the relative contributions of BMP-2 and Tmem119 to the osteogenic differentiation and the mechanisms involved are incompletely understood. In the present study, we examined the relationship among BMP-2, Tmem119, and the PERK-eIF2α-ATF4 endoplasmic reticulum (ER) stress response pathway in the differentiation of C2C12 myoblasts into osteoblastic cells. Both BMP-2 and Tmem119 induced levels of the osteoblast markers Runx2, Osterix, Col1a1, ALP, and osteocalcin, as well as mineralization. BMP-2 activation of the ER stress sensor PERK stimulated phosphorylation of eIF2α and led to increased biosynthesis of the osteoblast differentiation factor ATF4. When dephosphorylation of eIF2α was blocked by the selective inhibitor salubrinal, the osteogenic effects of BMP-2 and Tmem119 were enhanced further. Although BMP-2 stimulated both P-eIF2α and ATF4 levels, Tmem119 had no effect on P-eIF2α but stimulated ATF4 only. Reduction in endogenous Tmem119 levels by siRNA reduced both basal and BMP-2-stimulated levels of the ATF4 protein. In conclusion, BMP-2 stimulates differentiation of myoblasts into osteoblasts via the PERK-eIF2α-ATF4 pathway but in addition stimulates Tmem119, which itself increases ATF4. Hence, BMP-2 stimulates ATF4 both dependently and independently of the PERK-eIF2α ER stress response pathway.

One-hour post-load hyperglycemia by 75g oral glucose tolerance test as a novel risk factor of atherosclerosis.

Postprandial hyperglycemia is considered as a risk factor of cardiovascular disease. We hypothesized that early post-load hyperglycemia might be more useful surrogate marker to assess atherosclerosis than plasma glucose (PG) level at 120 minutes because the peak of post-load glucose by 75gOGTT is usually shown at 60 minutes. 75gOGTT and carotid echography were investigated in 108 subjects who visited our hospital to examine impaired glucose tolerance. The association of post-load plasma glucose and insulin levels with intima-media thickness (IMT) was examined. Simple correlation analyses showed that fasting PG (FPG) (r=0.26, p=0.013), PG60 (r=0.40, p<0.001), PG90 (r=0.29, p=0.008), area under curve for PG (AUC-PG) (r=0.33, p=0.003), HbA1c (r=0.30, p=0.005), amount of PG increase at 60 minutes (PGΔ60) (r=0.39, p=0.002), and PGΔ90 (r=0.27, p=0.016), were significantly correlated with IMT. Multiple regression analysis using IMT as a dependent variable and PG60, FPG, HbA1c, and AUC-PG as independent variables showed that PG60 was only significantly and positively correlated with IMT (ß=0.59, p=0.042). Moreover, PG60 and PGΔ60 were significantly and positively associated with IMT even after additional adjustment for classical atherosclerosis risk factors (ß=0.30, p=0.005 and ß=0.50, p=0.037, respectively). The cut-off values of PG60 and PGΔ60 to detect atherosclerosis (IMT > 1.1mm) were 188 and 101 mg/dL, respectively (p<0.01). These findings show that early post-load hyperglycemia, particularly PG60 is a novel risk factor of atherosclerosis and useful to assess it.

Sprengel deformity: morphometric assessment and surgical treatment by the modified green procedure.

BACKGROUND: We evaluated the pathologic anatomy of the Sprengel deformity using radiographs, 3-dimensional computed tomography (3D-CT), and magnetic resonance imaging (MRI), and reviewed our results of the modified Green procedure. METHODS: Between 2002 and 2009, 23 scapulae in 22 patients were treated. The average age at the time of surgery was 3.4 years (range, 1.9 to 7.1 y). The outcome of surgery was assessed on the basis of changes in shoulder abduction and the radiographic findings using Cavendish classification, Rigault classification, scapular elevation, and medialization. Preoperative appearance was classified as grade III in 13 cases and grade IV in 10 cases according to the Cavendish classification, and as grade II in 4 cases and grade III in 19 cases according to the Rigault classification. Using 3D-CT, we assessed the height to width ratio on the scapular posterior view, the superior displacement ratio and rotational difference on the trunk posterior view, and the anterior curvature of the supraspinous portion on the scapular medial view. RESULTS: The average follow-up postoperative period was 4.4 years (range, 2.2 to 8.7 y). Postoperatively, the shoulder abduction improved well, with a mean improvement of 63 degrees. Improvement of at least 1 Cavendish grade and 1 Rigault grade was attained in all cases. On preoperative 3D-CT, the mean height to width ratio of the affected scapula was significantly smaller than that of the contralateral scapula. There was an inverse relationship between the superior displacement ratio and the rotational difference. Anterior curvature of the supraspinous portion was seen in all cases. Omovertebral bone was found in 20 cases. MRI identified unossified omovertebral cartilage that was not evident by radiographs or CT. Transient brachial plexus palsy occurred in 2 patients, both of whom recovered within 4 months. Postoperative scapula winging and unsightly scarring were seen in 3 and 8 cases, respectively. CONCLUSIONS: 3D-CT and MRI were helpful in evaluating the pathologic anatomy of the deformity and in planning the surgery. The modified Green procedure provided successful functional and cosmetic results. LEVEL OF EVIDENCE: Level IV.

[Updates on Lifestyle-Related Diseases and Bone Metabolism. The metabolic syndrome and bone metabolism].

The metabolic syndrome is featured by the combination of obesity induced by visceral fat accumulation, dyslipidemia, hyperglycemia, and hypertension. It is well documented that obesity and body weight increase are positively linked to increased bone mineral density (BMD) and reduced fracture risk of weight-bearing bones through mechanical stress. On the other hand, inflammatory cytokines secreted from visceral fat and advanced glycation products induced by hyperglycemia tend to reduce BMD and to increase fracture risk in contrast to obesity. Thus, BMD and fracture risk in patients with the metabolic syndrome may be determined by the balance between the beneficial effect of obesity and detrimental ones of inflammatory cytokines and hyperglycemia on bone.