Factors Influencing Optimal Bracing Compliance in Adolescent Idiopathic Scoliosis: A Single Center Prospective Cohort Study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To identify factors contributing to optimal bracing compliance in adolescent idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

Poor brace compliance is a key factor affecting brace treatment success in AIS. Predictive factors influencing optimal brace compliance to achieve brace treatment success remain unknown.

MATERIALS AND METHODS

This study included AIS patients, aged 10-15, with a Cobb angle of 20-40 degrees. Demographics data, radiographic assessments, and patient-reported outcomes (including the SRS-22r patient questionnaire) were collected. Brace compliance was monitored using in-brace thermometers, defining optimal bracing time as more than 18 hours/day. Multivariable logistic regression analysis was employed to identify predictors of optimal bracing time from the demographic and patient- reported outcomes score before bracing.

RESULTS

Among 122 patients, 59.0% achieved optimal bracing time by six months. The achieved group indicated higher scores in satisfaction domain before bracing (3.3±0.7 vs. 3.1±0.6; P=0.034). Multivariable logistic regression analysis demonstrated that Satisfaction domain before bracing was an independent factor associated with achievement of the optimal bracing time (OR 1.97 [95%CI 1.00 - 3.89], P=0.049). The model with bracing at 1-month follow-up also demonstrated the bracing at 1-month was a significant factor (OR 1.52 [95%CI 1.30 - 1.79], P<0.001).

CONCLUSION

Optimal bracing compliance in AIS is significantly influenced by pre-bracing satisfaction and brace compliance at earlier time point. These findings highlight the need to address psychological factors and early compliance in AIS bracing treatment. SRS-22r can be useful to identify the need for psychological support.

Vero cell-adapted SARS-CoV-2 strain shows increased viral growth through furin-mediated efficient spike cleavage

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) utilizes several host proteases to cleave the spike (S) protein to enter host cells. SARS-CoV-2 S protein is cleaved into S1 and S2 subunits by furin, which is closely involved in the pathogenicity of SARS-CoV-2. However, the effects of the modulated protease cleavage activity due to S protein mutations on viral replication and pathogenesis remain unclear. Herein, we serially passaged two SARS-CoV-2 strains in Vero cells and characterized the cell-adapted SARS-CoV-2 strains in vitro and in vivo. The adapted strains showed high viral growth, effective S1/S2 cleavage of the S protein, and low pathogenicity compared with the wild-type strain. Furthermore, the viral growth and S1/S2 cleavage were enhanced by the combination of the Δ68-76 and H655Y mutations using recombinant SARS-CoV-2 strains generated by the circular polymerase extension reaction. The recombinant SARS-CoV-2 strain, which contained the mutation of the adapted strain, showed increased susceptibility to the furin inhibitor, suggesting that the adapted SARS-CoV-2 strain utilized furin more effectively than the wild-type strain. Pathogenicity was attenuated by infection with effectively cleaved recombinant SARS-CoV-2 strains, suggesting that the excessive cleavage of the S proteins decreases virulence. Finally, the high-growth-adapted SARS-CoV-2 strain could be used as the seed for a low-cost inactivated vaccine; immunization with this vaccine can effectively protect the host from SARS-CoV-2 variants. Our findings provide novel insights into the growth and pathogenicity of SARS-CoV-2 in the evolution of cell-cell transmission.

IMPORTANCE

The efficacy of the S protein cleavage generally differs among the SARS-CoV-2 variants, resulting in distinct viral characteristics. The relationship between a mutation and the entry of SARS-CoV-2 into host cells remains unclear. In this study, we analyzed the sequence of high-growth Vero cell-adapted SARS-CoV-2 and factors determining the enhancement of the growth of the adapted virus and confirmed the characteristics of the adapted strain by analyzing the recombinant SARS-CoV-2 strain. We successfully identified mutations Δ68-76 and H655Y, which enhance viral growth and the S protein cleavage by furin. Using recombinant viruses enabled us to conduct a virus challenge experiment in vivo. The pathogenicity of SARS-CoV-2 introduced with the mutations Δ68-76, H655Y, P812L, and Q853L was attenuated in hamsters, indicating the possibility of the attenuation of excessive cleaved SARS-CoV-2. These findings provide novel insights into the infectivity and pathogenesis of SARS-CoV-2 strains, thereby significantly contributing to the field of virology.

Measurement of Postoperative Apical Vertebral Rotation Using Radiographic Images in Adolescent Idiopathic Scoliosis-Quantitative Evaluation Using Inverse Trigonometric Functions

Introduction

Conventional methods for analyzing vertebral rotation are limited to postoperative patients who underwent posterior fusion. A previous methodology calculated vertebral rotation using inverse trigonometric functions based on the length of the pedicle screw (PS). Accordingly, this study evaluates rotational deformity in patients with postoperative adolescent idiopathic scoliosis (AIS) using inverse trigonometric functions.

Methods

This retrospective single-center study includes patients with AIS who underwent posterior fusion surgery. Postoperative radiography and computed tomography (CT) scans were retrospectively evaluated. The magnification ratio was calculated using the rod diameter (δ=lateral/frontal rod diameter), and the visible screw lengths were measured using radiographs. The rotation angle was calculated using the apex of the main curve and the lower instrumented vertebra (LIV) (rotation angle=tan-1 (lateral PS length/(δ×frontal PS length))) immediately following the surgery as well as two and five years postoperatively. The correlation between the direct CT measurement and postoperative rotation angle progression was investigated. The crankshaft phenomenon (CSP) and distal adding-on (DAO) were evaluated as postoperative deformities. CSP was defined as a 5° increase in rotation angle.

Results

Seventy-eight patients (age: 15.3±2.0 years, eight boys and seventy girls) were included. The rotation angle was strongly correlated with CT rotation measurements (r=0.87). The mean rotation angle at the apex and LIV did not change within five years postoperatively (mean: 0.5±3.6° and 0.4±3.4°, respectively). CSP and DAO were observed in 6.4% and 3.8% of patients, respectively.

Conclusions

The inverse trigonometric method is useful to quantitatively evaluate the postoperative rotation angle and identify CSP.

The Optimal Patient Position on the Surgical Table for Lateral Lumbar Interbody Fusion in Adult Spinal Deformity Using Three-Dimensional Computed Tomography: A Retrospective Study

Introduction

Lateral lumbar interbody fusion (LLIF) techniques have been extensively used in adult spinal deformity surgery. Preoperative knowledge of the optimal position of the patient on the surgical table is essential for a safe procedure. Therefore, this study aims to determine the optimal angle for positioning the patient on the surgical table during LLIF using three-dimensional computed tomography (3DCT).

Methods

Data from 59 patients (2 males, 57 females, mean age 66.3±8.6 years) with adult spinal deformities treated by performing corrective spinal surgery were included in this observational retrospective study. Simulated fluoroscopic images were obtained using 3DCT images rotated from the reference position with the spinous process of S1 as the midline to the position with the spinous process in the center of the bilateral pedicle of T12-L5. The rotation angle of each vertebra was measured and defined as the optimal rotation angle (ORA). The angle that bisected the angle between the maximum and minimum ORA was defined as the optimal mean angle of the maximum and minimum ORA (OMA) and considered the optimal angle for the patient's position on the surgical table, as this position could minimize the rotation angle of the surgical table during surgery. A multiple regression analysis was performed to predict OMA.

Results

Multiple regression analysis revealed the following equation: OMA=1.959+(0.238×lumbar coronal Cobb angle)+(-0.208×sagittal vertical axis).

Conclusions

When the patient is placed on the surgical table by rotating them at the OMA, the rotation of the surgical table can be reduced, ensuring a safe and efficient surgical procedure.

Machine learning algorithms for predicting Cobb angle beyond 25 degrees in female adolescent idiopathic scoliosis patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To develop a machine learning (ML) model that predicts the progression of AIS using minimal radiographs and simple questionnaires during the first visit.

SUMMARY OF BACKGROUND DATA

Several factors are associated with angle progression in patients with AIS. However, it is challenging to predict angular progression at the first visit.

METHODS

Among female patients with AIS treated at a single institution from July 2011 to February 2023, 1119 cases were studied. Patient data, including demographic and radiographic data based on anterior-posterior and lateral whole-spine radiographs, were collected at the first and last visits. The last visit was defined differently based on treatment plans. For patients slated for surgery or bracing, the last visit occurred just before these interventions. For others, it was their final visit before turning 18 years. Angular progression was defined as a Cobb angle greater than 25 degrees for each of the proximal thoracic (PT), main thoracic (MT), and thoracolumbar/lumbar (TLL) curves at the last visit. ML algorithms were employed to develop individual binary classification models for each type of curve (PT, MT, and TLL) using PyCaret in Python. Multiple models were explored and analyzed, with the selection of optimal models based on the area under the curve (AUC) and Recall scores. Feature importance was evaluated to understand the contribution of each feature to the model predictions.

RESULTS

For PT, MT, and TLL progression, the top-performing models exhibit AUC values of 0.94, 0.89, and 0.84, and achieve recall rates of 0.90, 0.85, and 0.81. The most significant factors predicting progression varied for each curve: initial Cobb angle for PT, presence of menarche for MT, and Risser grade for TLL.

CONCLUSIONS

This study introduces an ML-based model using simple data at the first visit to precisely predict angle progression in female patients with AIS.

Association of Spinal Corrective Surgery With Abdominal Aorta Length in Patients With Adult Spinal Deformity

Introduction This research aimed to explore the relationship between spinal characteristics and the length of the abdominal aorta in adult spinal deformity (ASD) patients who underwent corrective spinal surgery. We hypothesized that adjusting spinal alignment might affect the abdominal aorta's length. Methods This study included thirteen patients with ASD (average age: 63.0 ± 8.9 years; four males and nine females) who received spinal correction surgery. We measured both pre-operative and post-operative spinal parameters, including thoracolumbar kyphosis (TLK), and calculated their differences (Δ). The length of the aorta (AoL) was determined using an automated process that measures the central luminal line from the celiac artery's bifurcation to the inferior mesenteric artery. This measurement was made using contrast-enhanced computed tomography for three-dimensional aortic reconstruction. We compared the pre-operative and post-operative AoLs and their differences (Δ). The study examined the correlation between changes in spinal parameters and changes in AoL. Results Post-operatively, there was an increase in aortic length (ΔAoL: 4.2 ± 4.9 mm). There was a negative correlation between the change in TLK and the change in AoL (R2 = 0.45, p = 0.012, β = -0.21). No significant correlations were found with other spinal parameters. Conclusions The abdominal aorta can elongate by 4.8% after spinal corrective surgery in patients with ASD. The degree of elongation of the abdominal aorta is associated with spinal alignment correction.

Analysis of the relationship between spinal alignment and retrocrural space area in adult spinal deformity surgery: Potential risk factors for acute celiac artery compression syndrome

PURPOSE

This study was designed to reveal the association between spinal parameters and RCS area in patients with adult spinal deformities treated with spinal correction surgery. We hypothesized that reduction of the retrocrural space (RCS) area is related to thoracolumbar alignment, which may cause acute celiac artery compression syndrome (ACACS).

METHODS

Eighty-nine patients (age: 68.4 ± 7.6 years; sex: 7 male/82 female) with ASD treated by spinal correction surgery were enrolled. Preoperative and postoperative spinal parameters were measured, and the differences between these parameters were calculated. Postoperative T12 translation was measured and RCS area was evaluated using reconstructed computed tomography. The change of RCS area after surgery was defined as ΔRCS. Patients were divided into increased and decreased RCS groups by the ΔRCS value, and spinal parameters were compared between groups. The correlation between spinal parameters and ΔRCS was calculated.

RESULTS

The patients in the decreased RCS group had greater anterior T12 translation than those in the increased RCS group (p < 0.001). T12 translation was significantly correlated with ΔRCS (β = -0.31, p = 0.017). There were no correlations between ΔRCS and other spinal parameters.

CONCLUSION

Thoracolumbar alignment was associated with RCS area. Consistent with the hypothesis, overcorrection of the thoracolumbar junction was associated with reduced RCS area and might be one risk factor for ACACS.

Analysis of Rod Fracture at the Lumbosacral Junction Following Surgery for Adult Spinal Deformity

STUDY DESIGN

Retrospective study.

PURPOSE

This study aimed to investigate the differences in the characteristics of patients with rod fracture (RF) at the lumbosacral junction from those without RF following adult spinal deformity (ASD) surgery.

OVERVIEW OF LITERATURE

RF is a major complication following ASD surgery and may require reoperation because of pain and correction loss. The lumbosacral junction is a common RF site. However, risk factors for RFs at the lumbosacral junction remain unknown.

METHODS

The study included data from 100 patients who underwent ASD surgery between 2012 and 2020. Fifteen of these patients presented with RFs. Patient demographics, clinical outcomes, and radiographic parameters were evaluated in each group.

RESULTS

RFs were significantly more frequent in patients with a medical history of total hip arthroplasty (THA; p=0.01) or severe obesity (p=0.04). However, no significant differences in clinical outcomes, preoperative or postoperative measurements, or changes were found between pre- and postoperative radiographic parameters within the groups. Both pre- (p=0.01) and postoperative (p=0.02) anterior disc heights were significantly greater in the RF group than in the non-RF group. In the RF group, the postoperative lordotic angles of the lumbosacral junction significantly decreased compared with preoperative angles (p=0.02). Multiple logistic regression analysis demonstrated that a THA history (odds ratio, 34.2), severe obesity (odds ratio, 14.0), and preoperative anterior disc height (odds ratio, 1.2) were significant risk factors for RFs.

CONCLUSIONS

In this study, the greatest risk factors for postoperative lumbosacral RF after ASD surgery were THA history, severe obesity, and postoperative anterior disc height of ≥10. For patients at higher risk, the use of multirods is considered necessary.

Prevalence of pleural injury in an extrapleural approach to adolescent idiopathic scoliosis and association of pleural injury with postoperative respiratory function

BACKGROUND

The prevalence of pleural injury during surgery for adolescent idiopathic scoliosis using an extrapleural approach and the association of pleural injury with postoperative pulmonary function remain unclear. We sought to determine the prevalence of pleural injury associated with an extrapleural approach to adolescent idiopathic scoliosis, and to determine any difference in respiratory function between patients with or without pleural injury.

METHODS

Data from consecutive patients with scoliosis of the thoracolumbar/lumbar spine who underwent anterior spinal fusion using an extrapleural approach were assessed in this retrospective study. We had diagnosed and treated pleural injury according to our algorithm. Pre- and postoperative values of pulmonary function tests and postoperative change rates were compared between patients with and without pleural injury. FVC, %FVC, FEV1.0, and FEV1.0% were evaluated from pulmonary function tests.

RESULTS

We included data from 51 patients with adolescent idiopathic scoliosis (45 female and 6 male) with a mean age of 17.2 ± 3.5 years in this retrospective study. The group with pleural injury comprised 31 patients and the group without 20. Therefore, the prevalence of pleural injury during an extrapleural approach was 61%. We found no significant differences in preoperative FVC, %FVC, FEV1.0, and FEV1.0% between the groups. We found no significant differences in FVC, %FVC, FEV1.0, and FEV1.0% between the groups at 3 months or 1 year postoperatively. Furthermore, we found no significant differences in the postoperative change ratio of FVC, %FVC, FEV1.0, and FEV1.0% between the groups.

CONCLUSION

The prevalence of pleural injury associated with an extrapleural approach to scoliosis was 61%. Pleural injury was not associated with a decrease in postoperative pulmonary function in patients with scoliosis treated using an extrapleural approach.

Anatomical Analysis of the S1 Neural Foramen Using Three-Dimensional Computed Tomography Imaging: Insights for Effective S1 Nerve Root Block

OBJECTIVE

The first sacral nerve root block (S1 NRB) is used to diagnose and treat lumbosacral and radicular pain. This study aims to clarify the anatomy of the S1 neural foramen using three-dimensional (3D) computed tomography (CT) images and to establish the optimal fluoroscopic angle, localize the S1 neural foramen on fluoroscopy, and determine the safe puncture depth for S1 NRB.

METHODS

In this single-center cohort study, 200 patients with lumbar degenerative disease who underwent preoperative CT were enrolled. Four distinct studies were conducted using the CT data. Study 1 examined the correlation of the sacral slope angle and the supine and prone positions. Study 2 analyzed the tunnel view angle (TVA) using 3D reconstruction. Study 3 ascertained the location of the S1 neural foramen in fluoroscopy images. Study 4 investigated the safe depth for performing S1 NRB.

RESULTS

The regression analysis in Study 1 revealed a correlation of the sacral slope angle and the supine and prone positions. Study 2 determined an optimal fluoroscopic TVA of approximately 30° for the S1 NRB. Study 3 found that the S1 neural foramen was located caudal to the L5 pedicle 1.7 ± 0.2 times the distance between the L4 and L5 pedicles. Study 4 revealed that the depths of the S1 neural foramen and root were 27.0 ± 2.1 mm and 16.5 ± 2.0 mm, respectively.

CONCLUSIONS

Our study suggests an optimal fluoroscopic angle, a simple method to locate the S1 neural foramen on fluoroscopy, and an ideal puncture depth for a safe and effective S1 NRB.

Long-term changes in bone mineral density following adolescent idiopathic scoliosis surgery: a minimum 34-year follow-up

PURPOSE

To investigate longitudinal changes in bone mineral density (BMD) in middle-aged female patients who underwent spinal fusion for adolescent idiopathic scoliosis (AIS).

METHODS

The study subjects were 229 female patients who were diagnosed with AIS and underwent spinal fusion between 1968 and 1988. A two-step survey study was conducted on 19 female AIS patients. BMD, Z-scores, T-scores, and the prevalence of osteoporosis and osteopenia were compared between the initial (2014-2016) and second (2022) surveys. Correlations between the annual changes in Z-scores and T-scores with radiographic parameters, body mass index (BMI), and the number of remaining mobile discs were analyzed.

RESULTS

BMD decreased significantly from the initial (0.802 ± 0.120 g/cm2) to the second survey (0.631 ± 0.101 g/cm2; p < 0.001). Z-scores decreased from 0.12 ± 1.09 to - 0.14 ± 1.04, while T-scores decreased significantly from - 0.70 ± 1.07 to - 1.77 ± 1.11 (p < 0.001). The prevalence of osteopenia and osteoporosis increased significantly from 36.8% to 89.5% (p = 0.002), but the increase in osteoporosis alone was not statistically significant (5.3% to 26.3%; p = 0.180). Moderate negative correlations were found between annual changes in Z-scores and both main thoracic (MT) curve (r = - 0.539; p = 0.017) and lumbar curve (r = - 0.410; p = 0.081). The annual change in T-scores showed a moderate negative correlation with the MT curve (r = - 0.411; p = 0.081).

CONCLUSION

Significant reductions in BMD and an increased prevalence of osteopenia and osteoporosis were observed in middle-aged female AIS patients who had undergone spinal fusion. The decline in Z-scores in patients with AIS suggested that there was an accelerated loss of BMD compared with the general population. Larger residual curves could pose an added osteoporosis risk. Further research is needed to understand if the onset of osteoporosis in AIS patients is attributable to the condition itself or the surgical intervention.

Assessment of the Initial Diagnostic Accuracy of a Fragility Fracture of the Sacrum: A Study of 56 Patients

STUDY DESIGN

Retrospective study.

PURPOSE

To investigate the clinical manifestations of a fragility fracture of the sacrum (FFS) and the factors that may contribute to a misdiagnosis.

OVERVIEW OF LITERATURE

The number of patients diagnosed with FFS has increased because of extended life expectancy and osteoporosis. Patients with FFS may report nonspecific symptoms, such as back, buttock, groin, and/or leg pain, leading to a misdiagnosis and a delay in definitive diagnosis.

METHODS

Fifty-six patients (13 males and 43 females) with an average age of 80.2±9.2 years admitted to the hospital for FFS between 2006 and 2021 were analyzed retrospectively. The following patient data were collected using medical records: pain regions, a history of trauma, initial diagnoses, and rates of fracture detection using radiography, computed tomography (CT), and magnetic resonance imaging (MRI).

RESULTS

Forty-one patients presented with low back and/or buttock pain, nine presented with groin pain, and 17 presented with thigh or leg pain. There was no history of trauma in 18 patients (32%). At the initial visit, 27 patients (48%) were diagnosed with sacral or pelvic fragility fractures. In contrast, 29 patients (52%) were initially misdiagnosed with lumbar spine disease (23 patients), hip joint diseases (three patients), and buttock bruises (three patients). Fracture detection rates for FFS were 2% using radiography, 71% using CT, and 93% using MRI. FFS was diagnosed definitively using an MRI with a coronal short tau inversion recovery (STIR) sequence.

CONCLUSIONS

Some patients with FFS have leg pain with no history of trauma and are initially misdiagnosed as having lumbar spine disease, hip joint disease, or simple bruises. When these clinical symptoms are reported, we recommend considering FFS as one of the differential diagnoses and performing lumbar or pelvic MRIs, particularly coronal STIR images, to rule out FFS.

Incidence and Potential Risk Factors of Superior Mesenteric Artery Syndrome After Spinal Corrective Surgery in Patients with Adult Spinal Deformity

OBJECTIVE

This study aimed to determine the incidence and potential risk factors of superior mesenteric artery syndrome (SMAS) after corrective spinal surgery in patients with adult spinal deformity (ASD).

METHODS

In total, 102 patients (67.6 ± 8.4 years; 8 male/94 female; body mass index (BMI); 22.4 ± 3.6 kg/m2) with ASD treated by spinal correction surgery were enrolled. Preoperative and postoperative spinal parameters, including thoracolumbar kyphosis (TLK: T10-L2) and upper lumbar lordosis (ULL: L1-L4) were measured. To evaluate the potential risk factors of SMAS, the angle and the distance between the superior mesenteric artery and aorta, the aortomesenteric angle (AMA) and aortomesenteric distance (AMD), were evaluated pre- and postoperatively. Based on the postoperative AMA, AMD, and abdominal symptoms, the patients were diagnosed with SMAS. Correlations between demographic data or spinal parameters and AMA and AMD were assessed.

RESULTS

Two (2.0%) patients were diagnosed with SMAS. Postoperative TLK significantly correlated with postoperative AMA (P = 0.013, 0.046). Postoperative ULL was significantly correlated with postoperative AMD (β = -0.27; P = 0.014).

CONCLUSION

The incidence of SMAS after corrective spinal surgery in patients with ASD was 2.0%. Postoperative smaller TLK and greater ULL can be risk factors for developing SMAS. Spine surgeons should avoid overcorrection of the upper lumbar spine in the sagittal plane to prevent SMAS.

Hydroxyl Group Acetylation of Quercetin Enhances Intracellular Absorption and Persistence to Upregulate Anticancer Activity in HepG2 Cells

Quercetin, a flavonoid compound widely distributed in many plants, is known to have potent antitumor effects on several cancer cells. Our previous study revealed that the acetylation of quercetin enhanced its antitumor effect. However, the mechanisms remain unknown. This study aimed to elucidate the bioavailability of acylated quercetin in the HepG2 cell model based on its antitumor effect. The positions of quercetin 3,7,3',4'-OH were acetylated as 3,7,3',4'-O-tetraacetylquercetin (4Ac-Q). The inhibitory effect of 4Ac-Q on HepG2 cell proliferation was assessed by measuring cell viability. The apoptosis was characterized by apoptotic proteins and mitochondrial membrane potential shifts, as well as mitochondrial reactive oxygen species (ROS) levels. The bioavailability of 4Ac-Q was analyzed by measuring the uptake and metabolites in HepG2 cells with high performance liquid chromatography (HPLC)-photodiode array detector (PDA) and-ultraviolet/visible detector (UV/Vis). The results revealed that 4Ac-Q enhanced the inhibitory effect on HepG2 cell proliferation and induced its apoptosis significantly higher than quercetin. Protein array analysis of apoptosis-related protein indicated that 4Ac-Q increased the activation or expression of pro-apoptotic proteins, including caspase-3, -9, as well as second mitochondria-derived activator of caspases (SMAC), and suppressed the expression of apoptosis inhibiting proteins such as cellular inhibitor of apoptosis (cIAP)-1, -2, Livin, Survivin, and X-linked inhibitor of apoptosis (XIAP). Furthermore, 4Ac-Q stimulated mitochondrial cytochrome c release into the cytosol by enhancing ROS level and depolarizing the mitochondrial membrane. Finally, the analysis of uptake and metabolites of 4Ac-Q in HpG2 cells with HPLC-PDA and -UV/Vis revealed that 4Ac-Q was metabolized to quercetin and several different acetylated quercetins which caused 2.5-fold higher quercetin present in HepG2 cells than parent quercetin. These data demonstrated that acetylation of the quercetin hydroxyl group significantly increased its intracellular absorption. Taken together, our findings provide the first evidence that acetyl modification of quercetin not only substantially augments the intracellular absorption of quercetin but also bolsters its metabolic stability to elongate its intracellular persistence. Therefore, acetylation could serve as a strategic approach to enhance the ability of quercetin and analogous flavonoids to suppress cancer cell proliferation.

Risk factors for vertebral bridging in residual adolescent idiopathic scoliosis with thoracolumbar/lumbar curves

BACKGROUND

Although vertebral bridging in residual adolescent idiopathic scoliosis (AIS) can make corrective surgery more complicated, no study has investigated the risk factors. The purpose of this research was to determine risk factors for vertebral bridging in individuals with residual AIS with thoracolumbar/lumbar (TL/L) curves.

METHODS

Forty-two pre-operative patients with residual AIS and TL/L curves (3 males, 39 females: age 41.9 ± 18.0 years) were divided into bridging (n = 17) and non-bridging (n = 25) groups. All patients were 20 years or older with a diagnosis of AIS in adolescence. The bridging group consisted of patients with third or more degree bridging by the Nathan classification.

RESULTS

There were significant differences in age, absolute value of apical vertebral translation (AVT), C7 translation, and L3,4 tilt between groups. There was no significant difference in TL/L Cobb angle. Multivariate analyses and ROC curves demonstrated that older age was a significant risk factor for vertebral bridging (odds ratio [OR]: 1.08; 95% confidence interval: 1.02-1.14; P = 0.004), with a cutoff value of 38.0 years old.

CONCLUSIONS

This study indicates that patients >38 years old are at risk for vertebral bridging in residual AIS. Because of the higher risk of vertebral bridging and other degenerative changes, residual AIS patients about 40 years of age are at a critical point for treatment strategy. Because appropriate surgical time should not be missed, regular follow-up is required even after 30 years of age, especially if the patient with residual AIS has a large TL/L curve indicated for surgery.

Risk factors for celiac artery and superior mesenteric artery stenosis in preoperative lumbar and thoracolumbar spinal surgery patients

BACKGROUND

Ischemic necrosis of the abdominal organs caused by compression of the celiac artery (CA) and superior mesenteric artery (SMA) by the median arcuate ligament (MAL) after correction surgery has been recognized as acute celiac artery compression syndrome (ACACS). Here, using contrast-enhanced computed tomographic (CT) images, we sought to determine the prevalence and degree of CA and SMA stenosis in spinal patients preoperatively, and the risk factors associated with the stenosis.

METHODS

We retrospectively examined contrast-enhanced abdominal CT of 90 patients with preoperative lumbar degenerative disease, lumbar burst fracture, or adult spinal deformity. The trunks of the CA and SMA were detected using three-dimensional reconstructed CT. To investigate their degree of stenosis, we determined the ratio of the narrowest diameter of the stenotic segment to the distal normal lumen's diameter. Patients with a degree of stenosis ≥35% were defined as being in the group with stenosis and the remainder as in the group without. To determine the risk factors for stenosis of these arteries, the relationship between the stenosis and CA and SMA calcification or the median arcuate ligament (MAL) crossing the proximal portion of the celiac axis (MAL overlap) was also investigated.

RESULTS

The average degree of stenosis of the CA trunk was 12.1% ± 13.9% and that for the SMA trunk was 8.5% ± 8.8%. There were 8 patients (8.9%) in the group with CA stenosis and 2 patients (2.2%) in the group with SMA stenosis. The number of patients in the group with CA stenosis was significantly greater than the number with MAL overlap or CA calcification (P < 0.05).

DISCUSSION

The prevalence of CA or SMA stenosis was 11.2% of preoperative patients due to undergo thoracolumbar fusion surgery. Calcifications of the CA trunk and MAL overlap are risk factors for CA stenosis.

Genetic engineering strategy for generating a stable dsRNA virus vector using a virus-like codon-modified transgene

IMPORTANCE

The stabilities of transgenes in RNA virus vectors differ between the genes of interest, but the molecular mechanisms determining genetic stability remain unknown. This study demonstrated that the stability of a transgene was affected by the nucleotide composition, and altering the codon usage of transgenes to resemble that of the viral genome significantly increased transgene stability in double-stranded RNA virus vectors. The virus-like codon modification strategy enabled generation of stable rotavirus and mammalian orthoreovirus vectors, which could be developed as machinery for gene delivery to the intestines and/or respiratory organs. This technology has further potential to be expanded to other RNA viruses.

Efficient Selective Adsorption of SARS-CoV-2 via the Recognition of Spike Proteins Using an Affinity Spongy Monolith

Since the outbreak of COVID-19, SARS-CoV-2, the infection has been spreading to date. The rate of false-negative result on a polymerase chain reaction (PCR) test considered the gold standard is roughly 20%. Therefore, its accuracy poses a question as well as needs improvement in the test. This study reports fabrication of a substrate of an anti-spike protein (AS)-immobilized porous material having selective adsorption toward a spike protein protruding from the surface of SARS-CoV-2. We have employed an organic polymer substrate called spongy monolith (SPM). The SPM has through-pores of about 10 μm and is adequate for flowing liquid containing virus particles. It also involves an epoxy group on the surface, enabling arbitrary proteins such as antibodies to immobilize. When antibodies of the spike protein toward receptor binding domain were immobilized, selective adsorption of the spike protein was observed. At the same time, when mixed analytes of spike proteins, lysozymes and amylases, were flowed into an AS-SPM, selective adsorption toward the spike proteins was observed. Then, SARS-CoV-2 was flowed into the BSA-SPM or AS-SPM, amounts of SARS-CoV-2 adsorption toward the AS-SPM were much larger compared to the ones toward the BSA-SPM. Furthermore, rotavirus was not adsorbed to the AS-SPM at all. These results show that the AS-SPM recognizes selectively the spike proteins of SARS-CoV-2 and may be possible applications for the purification and concentration of SARS-CoV-2.

The Association Between Corrective Surgery for Adult Spinal Deformity and Serum Levels of Hepatobiliary Enzymes

Background and objective The surgery to correct adult spinal deformity (ASD) is associated with a rare, but life-threatening complication called acute celiac artery compression syndrome (ACACS). To our knowledge, there is currently no study in the literature regarding the abnormal elevation of serum levels of hepatobiliary enzymes after surgery to correct the deformity. In light of this, the purpose of this study was to investigate this potential association. Materials and methods We collected data on 74 patients with ASD who underwent correction surgery at our institution. A Spearman's rank-order correlation was used to assess the association between serum levels of hepatobiliary enzymes and spinal parameters. Factors showing a correlation coefficient of 0.2 or more were combined in a stepwise multiple regression analysis. Results The mean age of the patients was 68.4 ± 7.7 years; the study comprised six men and 68 women. In our stepwise multiple regression analysis, there were two valid models that included spinal parameters as independent variables: changes in lactate dehydrogenase (LDH) - changes in thoracolumbar kyphosis (TLK) (B -0.0025 ± 0.0007, p<0.01), and changes in LDH - preoperative T12-L1 kyphosis (B 0.0031 ± 0.001, p<0.01). Additionally, both valid models contained median arcuate ligament (MAL) overlap defined as MAL crossing the base of the celiac artery (CA) as a significant independent variable. Conclusions Greater sagittal correction of TLK, larger preoperative T12-L1 kyphosis, and MAL overlap were factors associated with an elevated serum level of LDH. Although few patients were reported to have clinically severe symptoms, "potential" ACACS due to a temporary blood flow disturbance can occur in this patient population.

Impact of Brace-Related Stress on Brace Compliance in Adolescent Idiopathic Scoliosis: A Single-Center Comparative Study Using Objective Compliance Measurement and Brace-Related Stress

Introduction

This study aimed to investigate the brace compliance and clinical background of patients with adolescent idiopathic scoliosis (AIS) who demonstrate different degrees of psychological brace-related stress.

Methods

Forty-five patients initiating brace treatment with a Cobb angle between 25° and 45° were included. Patients receiving brace treatment for AIS were administered a questionnaire for brace-related stress (i.e., the Japanese version of the Bad Sobernheim Stress Questionnaire-Brace [JBSSQ-brace]). Based on their scores, we allocated the patients into two stress groups: mild-stress (≥16 points) and below-moderate-stress (<16 points). We investigated the character of brace compliance and brace-related psychological stress in all patients and compared the demographics and brace compliance between both groups.

Results

Forty-one of 45 patients completed the study. The mean JBSSQ-brace scores were 18.7±5.1, 19.1±5.2, and 18.7±5.0 points at the 1-month, 4-month, and 1-year follow-ups, respectively. There was no significant change in JBSSQ-brace scores over one year after the brace prescription (P=0.332). There was no difference in-brace compliance between seasons during the first month of brace prescription (P=0.252). Both groups' overall brace compliance was comparable (below-moderate: 17.1±7.1 h/day vs. mild: 20.4±3.0 h/day; P=0.078). The mild-stress group showed better compliance than the below-moderate-stress group on weekdays (below-moderate: 17.0±6.9 h/day vs. mild: 20.5±2.8 h/day; P=0.048) and at nighttime (below-moderate: 82.3%±27.0%/nighttime vs. mild: 93.8%±12.4%/nighttime; P=0.008).

Conclusions

Overall, brace compliance was comparable among patients with different brace-related stress, but brace compliance during weekdays and nighttime was significantly better in the mild-stress group.

Risk Factors for Cage Subsidence in Minimally Invasive Lateral Corpectomy for Osteoporotic Vertebral Fractures

Introduction

This study aims to investigate risk factors for cage subsidence following minimally invasive lateral corpectomy for osteoporotic vertebral fractures.

Methods

Eight males and 13 females (77.2±6.0 years old) with osteoporotic vertebral fractures who underwent single corpectomy using a wide-footprint expandable cage with at least a 1-year follow-up were retrospectively included. The endplate cage (EC) angle was defined as the angle between the vertebral body's endplate and the cage's base on the cranial and caudal sides. A sagittal computed tomography scan was performed immediately after surgery and at the final follow-up, with cage subsidence defined as subsidence of ≥2 mm on the cranial or caudal side. Risk factors were analyzed by dividing cases into groups with (n=6) and without (n=15) cage subsidence.

Results

No significant differences were noted in age, bone mineral density, number of fixed vertebrae, sagittal parameters, preoperative and final kyphosis angle, amount of kyphosis angle correction, bone union, screw loosening, and number of other vertebral fractures preoperatively and 1-year postoperatively between the two groups. No difference was noted in cranial EC angle, but a significant difference was noted in caudal EC angle in the group with (10.7±4.1°) and without (4.7±4.2°) subsidence (P=0.008). Logistic regression analysis with the dependent variable as presence or absence of subsidence showed that caudal EC angle (>7.5°) was a significant factor (odds ratio: 20, 95% confidence interval: 1.655-241.7, P=0.018).

Conclusions

In minimally invasive lateral corpectomy for osteoporotic vertebral fractures, a cage tilted more than 7.5° to the caudal vertebral endplate is a risk factor for cage subsidence. The cage should be placed as perpendicular to the endplate as possible, especially to the caudal vertebral body, to avoid cage subsidence.

Effective SARS-CoV-2 replication of monolayers of intestinal epithelial cells differentiated from human induced pluripotent stem cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes severe acute respiratory symptoms in humans. Controlling the coronavirus disease pandemic is a worldwide priority. The number of SARS-CoV-2 studies has dramatically increased, and the requirement for analytical tools is higher than ever. Here, we propose monolayered-intestinal epithelial cells (IECs) derived from human induced pluripotent stem cells (iPSCs) instead of three-dimensional cultured intestinal organoids as a suitable tool to study SARS-CoV-2 infection. Differentiated IEC monolayers express high levels of angiotensin-converting enzyme 2 and transmembrane protease serine 2 (TMPRSS2), host factors essential for SARS-CoV-2 infection. SARS-CoV-2 efficiently grows in IEC monolayers. Using this propagation system, we confirm that TMPRSS2 inhibition blocked SARS-CoV-2 infection in IECs. Hence, our iPSC-derived IEC monolayers are suitable for SARS-CoV-2 research under physiologically relevant conditions.

Evidence of causality of low body mass index on risk of adolescent idiopathic scoliosis: a Mendelian randomization study

Introduction

Adolescent idiopathic scoliosis (AIS) is a disorder with a three-dimensional spinal deformity and is a common disease affecting 1-5% of adolescents. AIS is also known as a complex disease involved in environmental and genetic factors. A relation between AIS and body mass index (BMI) has been epidemiologically and genetically suggested. However, the causal relationship between AIS and BMI remains to be elucidated.

Material and methods

Mendelian randomization (MR) analysis was performed using summary statistics from genome-wide association studies (GWASs) of AIS (Japanese cohort, 5,327 cases, 73,884 controls; US cohort: 1,468 cases, 20,158 controls) and BMI (Biobank Japan: 173430 individual; meta-analysis of genetic investigation of anthropometric traits and UK Biobank: 806334 individuals; European Children cohort: 39620 individuals; Population Architecture using Genomics and Epidemiology: 49335 individuals). In MR analyses evaluating the effect of BMI on AIS, the association between BMI and AIS summary statistics was evaluated using the inverse-variance weighted (IVW) method, weighted median method, and Egger regression (MR-Egger) methods in Japanese.

Results

Significant causality of genetically decreased BMI on risk of AIS was estimated: IVW method (Estimate (beta) [SE] = -0.56 [0.16], p = 1.8 × 10-3), weighted median method (beta = -0.56 [0.18], p = 8.5 × 10-3) and MR-Egger method (beta = -1.50 [0.43], p = 4.7 × 10-3), respectively. Consistent results were also observed when using the US AIS summary statistic in three MR methods; however, no significant causality was observed when evaluating the effect of AIS on BMI.

Conclusions

Our Mendelian randomization analysis using large studies of AIS and GWAS for BMI summary statistics revealed that genetic variants contributing to low BMI have a causal effect on the onset of AIS. This result was consistent with those of epidemiological studies and would contribute to the early detection of AIS.

Health-Related Quality of Life of Patients With Adolescent Idiopathic Scoliosis at Least 40 Years After Surgery

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim was to clarify the health-related quality of life (QOL) of patients who had adolescent idiopathic scoliosis (AIS) at a minimum of 40 years after surgery.

SUMMARY OF BACKGROUND DATA

The postoperative health-related QOL of middle-aged patients with AIS has been reported to be good, but that of middle-aged and older patients with AIS has yet to be completely explored.

MATERIALS AND METHODS

We included 179 patients with AIS who underwent spinal fusion(s) between 1968 and 1982. We conducted three surveys in 2009, 2014, and 2022. Patients self-administered both the Scoliosis Research Society-22 and the Roland-Morris Disability questionnaires three times (in 2009, 2014, and 2022) and the Oswestry Disability Index (ODI) questionnaire was self-administered in 2014 and 2022. We considered patients who responded to all three surveys in 2009, 2014, and 2022.

RESULTS

For the Scoliosis Research Society-22 questionnaires, no significant differences were detected among the three time points (2009, 2014, and 2022) for total scores, function domain, pain domain, self-image domain, mental domain, or satisfaction domain. The results of the Roland-Morris Disability Questionnaire were also not significantly different among the surveys over time. The ODI questionnaires revealed a significant worsening of the 2022 results compared with the 2014 results. Eight patients (29.6%) who had an ODI deterioration of 10% or more had numerically fewer mobile lumbar disks than those with <10% deterioration of the ODI, although the difference did not reach statistical significance.

CONCLUSION

Among patients with AIS who underwent spinal fusion(s) between 1968 and 1982, we found health-related QOL to be maintained over the last 13 years. Relatively good QOL was appreciated in this population of patients who are now middle-aged and older.

Reduced Autophagy in Aged Trigeminal Neurons Causes Amyloid β Diffusion

The relationship between oral health and the development of Alzheimer's disease (AD) in the elderly is not yet well understood. In this regard, the association between aging or neurodegeneration of the trigeminal nervous system and the accumulation of amyloid-β(1-42) (Aβ₄₂) oligomers in the pathogenesis of AD is unknown. We focused on selective autophagy in the trigeminal mesencephalic nucleus (Vmes) and the diffusion of Aβ₄₂ oligomers with respect to aging of the trigeminal nervous system and whether the degeneration of Vmes neurons affects the diffusion of Aβ₄₂ oligomers. We used female 2- to 8-mo-old transgenic 3xTg-AD mice and App^NL-G-F knock-in mice and immunohistochemically examined aging-related changes in selective autophagy and Aβ₄₂ oligomer processing in the Vmes, which exhibits high amyloid-β (Aβ) expression. We induced degeneration of Vmes neurons by extracting the maxillary molars and examined the changes in Aβ₄₂ oligomer kinetics. Autophagosome-like membranes, which stained positive for Aβ, HO-1, and LC3B, were observed in Vmes neurons of 3xTg-AD mice, while there was weak immunoreactivity of the membranes for intraneuronal Aβ in App^NL-G-F mice. By contrast, there was strong immunopositivity for extracellular Aβ₄₂ oligomers with the formation of Aβ₄₂ oligomer clusters in App^NL-G-F mice. The expression of Rubicon, which indicates age-related deterioration of autophagy, increased the diffusion of Aβ₄₂ oligomer with the age of Vmes neurons. Tooth extraction increased the extracellular immunopositivity for Aβ₄₂ oligomers in App^NL-G-F mice. These results suggest that autophagy maintains homeostasis in Vmes neurons and that deterioration of autophagy due to aging or neurodegeneration leads to the diffusion of Aβ₄₂ oligomers into the extracellular space and possibly the development of AD.

Trunk flexibility using a sit-and-reach test after surgery for adolescent idiopathic scoliosis

PURPOSE

Spinal fusion reduces flexibility, but we do not have detailed knowledge that accounts for growth or sex differences. We sought to determine trunk flexibility pre- and postoperatively in patients with adolescent idiopathic scoliosis (AIS).

METHODS

We included data from 109 patients with AIS in this retrospective, single-center observational study. Patients had performed a sit-and-reach (SR) test preoperatively, and 1 and 2 years postoperatively, and measurements were standardized to Z scores according to age and sex. The patient data were divided into three groups according to the level of lower instrumented vertebra (LIV): (1) Group A (fusion above L2); (2) Group B (fusion to L2), and (3) Group C (fusion to L3 or L4). The change in the Z score for various levels was determined and compared.

RESULTS

The preoperative Z score for all patients was -0.622. At 2 years postoperatively, the Z score in Groups A and B was not significantly different from the preoperative score; in Group C, the Z score decreased by 1 year postoperatively, improved during the second year, but remained significantly lower than the preoperative score. Our study was the first to assess trunk flexibility using the SR test in patients with scoliosis.

CONCLUSIONS

Preoperatively, patients with AIS had lower SR test Z-scores than the general population, indicating a lower trunk flexibility in these patients. At 2 years after surgery in these patients, trunk flexibility had returned to preoperative levels when LIV was at L2 or above, but when LIV was at L3 or L4, trunk flexibility was less than it was preoperatively.

LEVEL OF EVIDENCE

Prognostic Level II: retrospective study.

Functional changes in cytotoxic CD8+ T-cell cross-reactivity against the SARS-CoV-2 Omicron variant after mRNA vaccination

Understanding the T-cell responses involved in inhibiting COVID-19 severity is crucial for developing new therapeutic and vaccine strategies. Here, we characterized SARS-CoV-2 spike-specific CD8⁺ T cells in vaccinees longitudinally. The BNT162b2 mRNA vaccine can induce spike-specific CD8⁺ T cells cross-reacting to BA.1, whereas the T-cell receptor (TCR) repertoire usages decreased with time. Furthermore the mRNA vaccine induced spike-specific CD8⁺ T cells subpopulation expressing Granzyme A (GZMA), Granzyme B (GZMB) and Perforin simultaneously in healthy donors at 4 weeks after the second vaccination. The induced subpopulation was not maintained at 12 weeks after the second vaccination. Incorporating factors that efficiently induce CD8⁺ T cells with highly cytotoxic activity could improve future vaccine efficacy against such variants.

Identification of a Functional Susceptibility Variant for Adolescent Idiopathic Scoliosis that Upregulates Early Growth Response 1 (EGR1)-Mediated UNCX Expression

Adolescent idiopathic scoliosis (AIS) is a serious health problem affecting 3% of live births all over the world. Many loci associated with AIS have been identified by previous genome wide association studies, but their biological implication remains mostly unclear. In this study, we evaluated the AIS-associated variants in the 7p22.3 locus by combining in silico, in vitro, and in vivo analyses. rs78148157 was located in an enhancer of UNCX, a homeobox gene and its risk allele upregulated the UNCX expression. A transcription factor, early growth response 1 (EGR1), transactivated the rs78148157-located enhancer and showed a higher binding affinity for the risk allele of rs78148157. Furthermore, zebrafish larvae with UNCX messenger RNA (mRNA) injection developed body curvature and defective neurogenesis in a dose-dependent manner. rs78148157 confers the genetic susceptibility to AIS by enhancing the EGR1-regulated UNCX expression. © 2022 American Society for Bone and Mineral Research (ASBMR).

Impact of the COVID-19 Pandemic on Middle-Aged and Older Patients With Adolescent Idiopathic Scoliosis Who Underwent Spinal Fusion: A Questionnaire-Based Survey

Purpose To investigate the impact of the COVID-19 pandemic on middle-aged and older patients with adolescent idiopathic scoliosis (AIS) who underwent spinal fusion. Methods The subjects were 252 AIS patients who underwent spinal fusion between 1968 and 1988. The surveys were performed before the COVID-19 pandemic (a primary survey in 2014) and during the pandemic (a secondary survey in 2022). The self-administered questionnaires were mailed to the patients. We analyzed 35 patients (33 females and two males) who replied to both surveys. Results The pandemic had low impacts on 11 patients (31.4%). Two patients reported refraining from seeing a doctor because they were concerned about going to the clinic or hospital, eight reported that the pandemic impacted their work, and five reported fewer opportunities to go out (based on multiple-choice answers). Twenty-four patients reported that their lives were unaffected by the pandemic. No significant differences were detected between both surveys for Scoliosis Research Society-22 (SRS-22) in any domains (function, pain, self-image, mental, or satisfaction). The Oswestry Disability Index (ODI) questionnaires revealed a significant worsening of the survey during the pandemic compared with the survey before the pandemic. There was no significant difference in the impact of the pandemic between the ODI deterioration group (27.8%) and the ODI stable group (35.3%). Conclusion The COVID-19 pandemic had a low impact on 31.4% of middle-aged and older patients with AIS who underwent spinal fusion. The impact of the pandemic did not significantly differ between the groups with ODI deteriorations and the groups with stable ODI. The pandemic had a smaller impact on AIS patients at a minimum of 33 years after surgery.

A reverse genetics system for human rotavirus G2P[4]

Rotaviruses (RVs) are an important cause of acute gastroenteritis in young children. Recently, versatile plasmid-based reverse genetics systems were developed for several human RV genotypes; however, these systems have not been developed for all commonly circulating human RV genotypes. In this study, we established a reverse genetics system for G2P[4] human RV strain HN126. Nucleotide sequence analysis, including that of the terminal ends of the viral double-stranded RNA genome, revealed that HN126 possessed a DS-1-like genotype constellation. Eleven plasmids, each encoding 11 gene segments of the RV genome, and expression plasmids encoding vaccinia virus RNA capping enzyme (D1R and D12L), Nelson Bay orthoreovirus FAST, and NSP2 and NSP5 of HN126, were transfected into BHK-T7 cells, and recombinant strain HN126 was generated. Using HN126 or simian RV strain SA11 as backbone viruses, reassortant RVs carrying the outer and intermediate capsid proteins (VP4, VP7 and VP6) of HN126 and/or SA11 (in various combinations) were generated. Viral replication analysis of the single, double and triple reassortant viruses suggested that homologous combination of the VP4 and VP7 proteins contributed to efficient virus infectivity and interaction between other viral or cellular proteins. Further studies of reassortant viruses between simian and other human RV strains will contribute to developing an appropriate model for human RV research, as well as suitable backbone viruses for generation of recombinant vaccine candidates.

Medical Accidents Related to Ferromagnetic Objects Brought into the MRI Room: Analysis of the National Multicenter Database by Orthopedic Surgeons

Introduction

Magnetic resonance imaging (MRI) is widely used in orthopedics, but orthopedic surgeons, including spine surgeons, do not have detailed knowledge of MRI-related accidents. We, as orthopedic surgeons, investigated the details of medical accidents related to ferromagnetic objects brought into the MRI room using a national multicenter database.

Methods

We conducted an exploratory analysis of accidents involving MRI ferromagnets based on the Japanese database of adverse medical occurrences. From a total of 104,659 accident reports over nine years, 172 involving the presence of ferromagnetic objects in the MRI room were extracted and analyzed.

Results

The accident reports frequently involved children and the elderly. Nurses filed the highest number of reports (44.8%) by occupation, which was more than twice as many as physicians (19.8%). The most common ferromagnetic devices brought into the MRI rooms were pacemakers (n = 22). There were also large magnetic objects such as oxygen cylinders (n = 12) and IV stands (n = 7). In the field of orthopedics, ankle weights (n = 4), pedometers (n = 3), and artificial limbs (n = 2) were brought in. "Failure to check" was the most common cause of accidents (69%). Actual harm to patients occurred in 9% of cases, with no fatalities.

Conclusions

Manuals and checklists should be developed and continuous education provided to prevent accidents involving magnetic objects brought into the MR scanner room. As orthopedic surgeons, including spine surgeons, we should be cautious with emergency, geriatric, and pediatric patients because their information and medical history may not be accurate. We should not overlook equipment commonly found in orthopedic practice such as ankle weights and pedometers.

Cell response analysis in SARS-CoV-2 infected bronchial organoids

The development of an in vitro cell model that can be used to study severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) research is expected. Here we conducted infection experiments in bronchial organoids (BO) and an BO-derived air-liquid interface model (BO-ALI) using 8 SARS-CoV-2 variants. The infection efficiency in BO-ALI was more than 1,000 times higher than that in BO. Among the bronchial epithelial cells, we found that ciliated cells were infected with the virus, but basal cells were not. Ciliated cells died 7 days after the viral infection, but basal cells survived after the viral infection and differentiated into ciliated cells. Fibroblast growth factor 10 signaling was essential for this differentiation. These results indicate that BO and BO-ALI may be used not only to evaluate the cell response to SARS-CoV-2 and coronavirus disease 2019 (COVID-19) therapeutic agents, but also for airway regeneration studies.

Risk Factors for Lateral Translation in Residual Adolescent Idiopathic Scoliosis with a Thoracolumbar/Lumbar Curve

Introduction

Although lateral vertebral translation is associated with inducing curve progression and pain, no study has analyzed risk factors for lateral slip in patients with residual adolescent idiopathic scoliosis (AIS). This study aimed to investigate risk factors for lateral slip in patients with residual AIS.

Methods

We included 42 preoperative patients with residual AIS with a thoracolumbar/lumbar (TL/L) curve (3 male, 39 female; age 41.9±18.2 years, TL/L Cobb angle 55.5±10.0°). All patients were >20 years and had been diagnosed with AIS during their adolescence. Lateral slip was defined as more than a 6-mm slip on coronal CT images.

Results

Patients were divided into slip (n=22) and nonslip (n=20) groups. Significant differences were observed in age, TL/L Cobb angle, TL/L curve flexibility, lumbar lordosis, thoracolumbar kyphosis, apical vertebral rotation, apical vertebral translation, and L3 and L4 tilt between the groups. Multivariate analyses and receiver operating characteristic curves found that only older age was a significant risk factor for lateral slip (odds ratio: 1.214; 95% confidence interval: 1.047-1.407; P=0.010), with a cutoff value of 37 years old.

Conclusions

Older age, especially >37 years, is a risk factor for lateral slip in patients with residual AIS. These findings suggest that surgery for residual AIS should be considered before patients are in their mid-30s to avoid lateral translation.

The Optimal Anatomical Position and Threshold Temperature of a Temperature Data Logger for Brace-Wearing Compliance in Patients with Scoliosis

Introduction

Although strict compliance with brace wearing is important for patients with scoliosis, no study has analyzed the most ideal conditions for temperature logger accuracy. We evaluated the optimal brace position and threshold temperature for the logger and determined the reliability of its measurements in patients with scoliosis.

Methods

Five temperature loggers were embedded into holes generated at five different brace positions (right scapula, right chest, left chest, lumbar, and abdomen) within the brace. We compared measurement errors at each position using different threshold temperatures to determine the ideal anatomical position and threshold temperature. Under the ideal conditions determined, we calculated the reliability of the temperature logger readings in three healthy participants.

Results

Measurement errors (i.e., differences between the actual and logger-recorded brace wearing times) were the lowest at the 28°C and 30°C threshold temperatures when the logger was positioned at the left chest and at 30°C at the abdomen. Among these three temperature/position combinations, we considered the abdomen to be the least affected by the shape of the brace; thus, the placement of the temperature logger at the abdomen using a threshold temperature of 30°C was the most ideal condition.

Conclusions

The placement of the temperature logger at the abdomen using a threshold temperature of 30°C was the most ideal condition, with the reliability of the logger being 97.9%±0.9%. This information might be useful for scoliosis management teams, and this temperature logger provides a valuable clinical tool.

Zoonotic Infection with Oz Virus, a Novel Thogotovirus

Oz virus is a novel thogotovirus isolated from ticks that causes lethal infection in mice. We conducted serosurveillance of Oz virus infection among humans and wild mammals in Japan using virus-neutralization tests and ELISAs. Results showed that Oz virus may be naturally infecting humans and other mammalian hosts.

SARS-CoV-2 infection triggers paracrine senescence and leads to a sustained senescence-associated inflammatory response

Reports of post-acute COVID-19 syndrome, in which the inflammatory response persists even after SARS-CoV-2 has disappeared, are increasing¹, but the underlying mechanisms of post-acute COVID-19 syndrome remain unknown. Here, we show that SARS-CoV-2-infected cells trigger senescence-like cell-cycle arrest^2,3 in neighboring uninfected cells in a paracrine manner via virus-induced cytokine production. In cultured human cells or bronchial organoids, these SASR-CoV-2 infection-induced senescent cells express high levels of a series of inflammatory factors known as senescence-associated secretory phenotypes (SASPs)⁴ in a sustained manner, even after SARS-CoV-2 is no longer detectable. We also show that the expression of the senescence marker CDKN2A (refs. ^5,6) and various SASP factor⁴ genes is increased in the pulmonary cells of patients with severe post-acute COVID-19 syndrome. Furthermore, we find that mice exposed to a mouse-adapted strain of SARS-CoV-2 exhibit prolonged signs of cellular senescence and SASP in the lung at 14 days after infection when the virus was undetectable, which could be substantially reduced by the administration of senolytic drugs⁷. The sustained infection-induced paracrine senescence described here may be involved in the long-term inflammation caused by SARS-CoV-2 infection.

Large Lumbar Lordosis Is a Risk Factor for Lumbar Spondylolysis in Patients with Adolescent Idiopathic Scoliosis

STUDY DESIGN

A retrospective, single-center, observational study.

OBJECTIVE

The aim of this study was to determine the prevalence and the characteristics of adolescent idiopathic scoliosis (AIS) patients with concomitant lumbar spondylolysis.

SUMMARY OF BACKGROUND DATA

The prevalence and features of lumbar spondylolysis in patients with AIS are unclear.

METHODS

We included 357 patients with AIS who underwent correction and fusion surgery. Preoperative computed tomography (CT) images were used to assess the existence of lumbar spondylolysis. Cobb angles of the curves, parameters of spinal alignment, Lenke classification, and the presence of low back pain were compared between patients with and without spondylolysis.

RESULTS

Of the patients included in the study, 6.1% had lumbar spondylolysis. They had significantly greater lumbar lordosis (LL) and sacral slope (SS) than those without lumbar spondylolysis. Logistic regression analyses and receiver-operating characteristic curves showed that LL was a significant risk factor (odds ratio: 1.059; 95% confidence interval: 1.018-1.103; P = 0.005) of associating lumbar spondylolysis with a cut off value of 56.5 degrees (area under the curve [AUC]: 0.689; sensitivity = 63.6%, specificity = 71.0%).

CONCLUSION

We should be vigilant for lumbar spondylolysis in AIS patients whose LL and SS are large, especially with LL larger than 56.5°.Level of Evidence: 3.

Epidemiological study of Kabuto Mountain virus, a novel uukuvirus, in Japan

Kabuto Mountain virus (KAMV), the new member of the genus Uukuvirus, was isolated from the tick Haemaphysalis flava in 2018 in Japan. To date, there is no information on KAMV infection in human and animals. Therefore, serological surveillance of the infection among humans and wild mammals was conducted by virus-neutralization (VN) test and indirect immunofluorescence assay (IFA). Sera of 24 humans, 59 monkeys, 171 wild boars, 233 Sika deer, 7 bears, and 27 nutria in Yamaguchi Prefecture were analyzed by VN test. The positive ratio of humans, monkeys, wild boars, and Sika deer were 20.8%, 3.4%, 33.9% and 4.7%, respectively. No positive samples were detected in bears and nutria. The correlation coefficients between VN test and IFA in human, monkey, wild boar, and Sika deer sera were 0.5745, 0.7198, 0.9967 and 0.9525, respectively. In addition, KAMV was detected in one pool of Haemaphysalis formosensis ticks in Wakayama Prefecture. These results indicated that KAMV or KAMV-like virus is circulating among many wildlife and ticks, and that this virus incidentally infects humans.

What factor induces stress in patients with AIS under brace treatment? Analysis of a specific factor using exploratory factor analysis

BACKGROUND

Stress from brace treatment in patients with adolescent idiopathic scoliosis (AIS) can deteriorate their quality of life. A Japanese version of the Bad Sobernheim Stress Questionnaire-Brace (JBSSQ-brace) was developed to assess the stress from brace treatment for Japanese patients with AIS. However, the specific factors causing stress under brace treatment have remained unknown.

METHOD

We enrolled 69 consecutive Japanese patients with AIS. Stress from brace treatment was assessed by JBSSQ-brace and Scoliosis Research Society-22 (SRS-22) instruments. The correlations of JBSSQ-brace with SRS-22 score, patient demographics and Cobb angle were analyzed by Spearman's rank correlation. Exploratory factor analysis was used to determine the psychological factor causing stress from brace treatment.

RESULTS

JBSSQ-brace score was correlated with total score of SRS-22, self-image and mental health domain, but not age, degree of curvature, or other domains of the SRS-22. Factor analysis detected one underlying factor, which was more related to Questions 4 or 5 with the factor loadings of 0.8 than Questions 1 or 6 with loadings of 0.65.

CONCLUSION

Stress from brace treatment was not associated with age, spinal curve severity, pain, or satisfaction of treatment. Exploratory factor analysis suggested "anxious feeling about how we are perceived by others" induces the stress from brace treatment in Japanese patients with AIS.

Polygenic Risk Score of Adolescent Idiopathic Scoliosis for Potential Clinical Use

Adolescent idiopathic scoliosis (AIS) is a common disease causing three-dimensional spinal deformity in as many as 3% of adolescents. Development of a method that can accurately predict the onset and progression of AIS is an immediate need for clinical practice. Because the heritability of AIS is estimated as high as 87.5% in twin studies, prediction of its onset and progression based on genetic data is a promising option. We show the usefulness of polygenic risk score (PRS) for the prediction of onset and progression of AIS. We used AIS genomewide association study (GWAS) data comprising 79,211 subjects in three cohorts and constructed a PRS based on association statistics in a discovery set including 31,999 female subjects. After calibration using a validation data set, we applied the PRS to a test data set. By integrating functional annotations showing heritability enrichment in the selection of variants, the PRS demonstrated an association with AIS susceptibility (p = 3.5 × 10^-40 with area under the receiver-operating characteristic [AUROC] = 0.674, sensitivity = 0.644, and specificity = 0.622). The decile with the highest PRS showed an odds ratio of as high as 3.36 (p = 1.4 × 10^-10 ) to develop AIS compared with the fifth in decile. The addition of a predictive model with only a single clinical parameter (body mass index) improved predictive ability for development of AIS (AUROC = 0.722, net reclassification improvement [NRI] 0.505 ± 0.054, p = 1.6 × 10^-8 ), potentiating clinical use of the prediction model. Furthermore, we found the Cobb angle (CA), the severity measurement of AIS, to be a polygenic trait that showed a significant genetic correlation with AIS susceptibility (rg = 0.6, p = 3.0 × 10^-4 ). The AIS PRS demonstrated a significant association with CA. These results indicate a shared polygenic architecture between onset and progression of AIS and the potential usefulness of PRS in clinical settings as a predictor to promote early intervention of AIS and avoid invasive surgery. © 2021 American Society for Bone and Mineral Research (ASBMR).

Histopathological Characterization of Cases of Spontaneous Fatal Feline Severe Fever with Thrombocytopenia Syndrome, Japan

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tickborne infectious disease caused by SFTS virus (SFTSV). We report 7 cases of spontaneous fatal SFTS in felines. Necropsies revealed characteristic lesions, including necrotizing lymphadenitis in 5 cases and necrotizing splenitis and SFTSV-positive blastic lymphocytes in all cases. We detected hemorrhagic lesions in the gastrointestinal tract in 6 cases and lungs in 3 cases, suggesting a more severe clinical course of SFTS in felids than in humans. We noted necrotic or ulcerative foci in the gastrointestinal tract in 3 cases, the lung in 2 cases, and the liver in 4 cases. We clarified that blastic lymphocytes are predominant targets of SFTSV and involved in induction of necrotic foci. We also found that thymic epithelial cells were additional targets of SFTSV. These results provide insights for diagnosing feline SFTS during pathological examination and demonstrate the similarity of feline and human SFTS cases.

Combining machine learning and nanopore construction creates an artificial intelligence nanopore for coronavirus detection

High-throughput, high-accuracy detection of emerging viruses allows for the control of disease outbreaks. Currently, reverse transcription-polymerase chain reaction (RT-PCR) is currently the most-widely used technology to diagnose the presence of SARS-CoV-2. However, RT-PCR requires the extraction of viral RNA from clinical specimens to obtain high sensitivity. Here, we report a method for detecting novel coronaviruses with high sensitivity by using nanopores together with artificial intelligence, a relatively simple procedure that does not require RNA extraction. Our final platform, which we call the artificially intelligent nanopore, consists of machine learning software on a server, a portable high-speed and high-precision current measuring instrument, and scalable, cost-effective semiconducting nanopore modules. We show that artificially intelligent nanopores are successful in accurately identifying four types of coronaviruses similar in size, HCoV-229E, SARS-CoV, MERS-CoV, and SARS-CoV-2. Detection of SARS-CoV-2 in saliva specimen is achieved with a sensitivity of 90% and specificity of 96% with a 5-minute measurement.

A serological survey and characterization of Getah virus in domestic pigs in Thailand, 2017-2018

Getah virus (GETV) is a mosquito-borne RNA virus belonging to the family Togaviridae, genus Alphavirus. GETV infection causes diarrhoea and death in piglets, and reproductive failure and abortion in sows. This study conducted a serological survey of GETV infection among domestic pig populations in Thailand. ELISA was used to analyse 1,188 pig serum samples collected from 11 provinces of Thailand during 2017-2018, with 23.1% of the samples being positive for anti-GETV antibodies. The positive ratio of anti-GETV antibodies was significantly higher in nursery (67.9%) and older stages (84.5%) of pigs than in finishing stage (14.2%). Furthermore, we successfully isolated GETV from one pig serum, designated as GETV strain GETV/SW/Thailand/2017, and determined the complete genome sequence (11,689 nt). Phylogenetic analysis demonstrated that our isolate was different from the recent GETV group spreading among pig populations in East Asia and formed a cluster with two GETV strains, namely YN12031 (China, 2015) and LEIV16275Mar (Far-East Russia, 2007). We concluded that two different GETV groups are currently spreading among pig populations in Asian countries.

New canine parvovirus 2a infection in an imported Asian small-clawed otter (Aonyx cinereus) in Japan

Post-import from the Republic of Indonesia to Japan in 2017, two juvenile, captive bred Asian small-clawed otters (Aonyx cinereus) exhibited gastrointestinal symptoms, including vomiting, diarrhea, and hematemesis, and died. One of them was examined postmortem. Microscopically, the small intestinal mucosa was necrotic with crypts lined by regenerating large epithelial cells. A gastric cardiac mucosal ulcerative lesion containing fungal yeasts and pseudohyphae morphologically indicated Candida spp. The lymph nodes exhibited marked lymphoid depletion. Canine parvovirus 2 (CPV-2) was isolated from an oral swab, and virus protein 2 (VP2) gene sequencing revealed new CPV-2a. To our knowledge, this is the first new CPV-2a infection report in Asian small-clawed otters. This infection should be considered in gastrointestinal symptom-related cases in this species.

Automated classification of hip fractures using deep convolutional neural networks with orthopedic surgeon-level accuracy: ensemble decision-making with antero-posterior and lateral radiographs

Background and purpose - Deep-learning approaches based on convolutional neural networks (CNNs) are gaining interest in the medical imaging field. We evaluated the diagnostic performance of a CNN to discriminate femoral neck fractures, trochanteric fractures, and non-fracture using antero-posterior (AP) and lateral hip radiographs. Patients and methods - 1,703 plain hip AP radiographs and 1,220 plain hip lateral radiographs were included in the total dataset. 150 images each of the AP and lateral views were separated out and the remainder of the dataset was used for training. The CNN made the diagnosis based on: (1) AP radiographs alone, (2) lateral radiographs alone, or (3) both AP and lateral radiographs combined. The diagnostic performance of the CNN was measured by the accuracy, recall, precision, and F1 score. We further compared the CNN's performance with that of orthopedic surgeons. Results - The average accuracy, recall, precision, and F1 score of the CNN based on both anteroposterior and lateral radiographs were 0.98, 0.98, 0.98, and 0.98, respectively. The accuracy of the CNN was comparable to, or statistically significantly better than, that of the orthopedic surgeons regardless of radiographic view used. In the CNN model, the accuracy of the diagnosis based on both views was significantly better than the lateral view alone and tended to be better than the AP view alone. Interpretation - The CNN exhibited comparable or superior performance to that of orthopedic surgeons to discriminate femoral neck fractures, trochanteric fractures, and non-fracture using both AP and lateral hip radiographs.