Zezhang Zhu

Decreased circulating leptin level and its association with body and bone mass in girls with adolescent idiopathic scoliosis.

Study Design. A prospective study was designed to investigate the circulating leptin level in girls with adolescent idiopathic scoliosis (AIS). Objective. To determine the circulating leptin levels in AIS girls, and to investigate its associations with body mass and bone mass. Summary of Background Data. Abnormal growth pattern and osteopenia have been well documented in AIS patients throughout the peripubertal growth period. Leptin has been shown to regulate the growth of the whole body and bone particularly during childhood and adolescence. However, the circulating level of leptin, the relationships between leptin and lower body mass, and the relationships between leptin and lower bone mass in AIS patients remain unclear. Methods. One hundred twenty AIS girls and 80 healthy controls were recruited in this study. Measurements of anthropometry and circulating leptin were performed both in AIS and non-AIS girls. Evaluations of curve severity and measurements of bone mineral content/density (BMC/BMD) were performed only in AIS girls. The anthropometric data and circulating leptin levels were compared between older AIS girls and controls. The relationships between leptin and age, menstrual status, body weight, height, body mass index (BMI), Risser sign, curve magnitude, and BMC/BMD were analyzed in AIS girls. Results. Compared with healthy controls, an abnormal growth pattern (higher corrected height, lower weight, and lower BMI), and a marked decrease of circulating leptin were found in AIS girls, even after the adjustment for age and menstrual status. Positive correlations were found between leptin and age, menstrual status, body weight, height, BMI, and Risser sign. No significant correlation was found between leptin and curve magnitude. There was no significant difference in age at menarche between menstruating AIS and non-AIS girls, though an inverse correlation was observed between leptin and the age at menarche. The relationship between leptin and BMC/BMD remained significantly positive after controlling for age and menstrual status, although it was not independent of body weight or BMI. Conclusion. A marked decrease of circulating leptin was observed in the current study. There was an association between leptin and body weight, BMI, other growth parameters, and BMC/BMD. This correlation suggests that leptin might play an important role in the lower body and bone mass in AIS girls.

Sagittal alignment of spine and pelvis in asymptomatic adults: norms in Chinese populations.

Study Design. A prospective, cross-sectional study. Objective. To investigate the normal values of sagittal spinal and pelvic parameters in Chinese populations and to determine the influence of age, sex, weight, and ethnicity on variations of these parameters. Summary of Background Data. A few studies have been conducted to evaluate the morphology and orientation of pelvis in asymptomatic adults of Caucasian populations. However, there is still a lack of investigation concerning the normal range of spinal and pelvic alignment in Asian populations. Methods. A cohort of 260 asymptomatic adult volunteers from Chinese Han populations was prospectively recruited. The following 6 radiological parameters on lateral radiograph were evaluated for each subject, including sacral slope (SS), pelvic tilt, pelvic incidence, thoracic kyphosis, lumbar lordosis, and C7 tilt. Comparisons of these parameters between the male and the female and between Chinese Han populations and Caucasian populations were carried out with Student t tests. The relationships between all parameters and age and weight were assessed using the Pearson correlation analysis. Results. The mean values of spinopelvic parameters of the cohort were 44.6 ± 11.2° for pelvic incidence, 11.2 ± 7.8° for pelvic tilt, and 32.5 ± 6.5° for SS, respectively. With the age matched, subjects from Chinese populations were found to have significantly smaller pelvic incidence and SS than those from Caucasian populations. The females were found to have significantly higher lumbar lordosis than the males. Presenting significant but small correlations with age of both male and female adults, thoracic kyphosis and pelvic tilt tended to increase with age, whereas SS had a tendency to decrease with age. Weight was significantly correlated with thoracic kyphosis, SS, and lumbar lordosis. Conclusion. The normal values of sagittal spinal and pelvic parameters in Chinese populations could be significantly influenced by age, weight, and sex. Moreover, obvious variations of spinopelvic parameters were found between populations with different ethnicity background. Level of Evidence: N/A

Extraordinary optical transmission induced by excitation of a magnetic plasmon propagation mode in a diatomic chain of slit-hole resonators

In this paper, we will propose that magnetic-resonance nanostructures in a metal surface could be used to realize extraordinary optical transmission EOT. Toward this goal, we designed and fabricated a onedimensional diatomic chain of slit-hole resonator SHR. Due to the strong exchange current interaction, a type of magnetic plasmon MP propagation mode with a broad frequency bandwidth was established in this system. Apparent EOT peaks induced by the MP mode were observed in our measured spectra at infrared frequencies. The strongest EOT peak was obtained at 1.07 eV with an incident angle of 20°. The measured dependence of EOT peaks on the incident angle coincided with the theoretical results quite well. This proposed MP propagation mode in SHR structure has good potential applications in multifrequency nonlinear optical processes.

Reliability analysis of a smartphone-aided measurement method for the Cobb angle of scoliosis.

Study Design: A comparison between the smartphone-aided measurement method and the manual measurement method for the Cobb angle in adolescent idiopathic scoliosis. Objective: To evaluate the reliability and measurement error for the smartphone-aided Cobb angle measurement method and compare its reliability and measurement error with those of the manual method. Summary of Background Data: The development of smartphones has provided new opportunities that integrate mobile technology into daily clinical practice. Smartphone applications can provide quick assistance in the diagnosis and treatment of disease. Cobbmeter is a smartphone application designed for the measurement of Cobb angle on Apple iPhone smartphones. There is no study on the reliability and measurement error of this smartphone-aided measurement method. Methods: Fifty-three posteroanterior radiographs of adolescent idiopathic scoliosis patients with thoracic scoliosis were used for the standard Cobb method of measurement (manual set) and the smartphone-aided Cobb method of measurement (smartphone set). Five spinal surgeons measured the Cobb angle with the use of both the manual method and the smartphone-aided method. The measurement time was recorded for every measurement. The frequency and the cumulative percent distribution for intraobserver differences were tabulated, both for the individual examiners and for the overall results for the 5 examiners. The intraclass correlation coefficient (ICC) 2-way mixed model on absolute agreement was used to analyze measurement reliability. Summary statistics from analyses of variance calculations were used to provide 95% prediction limits for the error in measurements. A paired t test was used to compare the time consumed for the measurement between both sets. Results: The intraobserver and interobserver ICCs were excellent in the smartphone set and in the manual set. Both the intraobserver ICC and the interobserver ICC were better in the smartphone set than in the manual set. The mean Cobb angle of all measured x-rays was 29.3 degrees (range, 17–58 degrees) in the manual set and 29.1 degrees (range, 18–56 degrees) in the smartphone set. The mean time consumed was 13.7 seconds (range, 8.6–18.5 s) for the smartphone set, whereas it was 37.9 seconds (range, 30.1–46.9 s) for the manual set, and the mean time consumed for the smartphone set was significantly shorter than that of the manual set (P<0.05). Conclusions: Smartphone-aided measurement for Cobb angle showed excellent reliability and efficiency. It is suggested to popularize the use of this method in clinical practice.

The Influence of Closing-opening Wedge Osteotomy on Sagittal Balance in Thoracolumbar Kyphosis Secondary to Ankylosing Spondylitis: A Comparison With Closing Wedge Osteotomy

Study Design. A retrospective study. Objective. To compare the radiographical and clinical outcomes between closing wedge osteotomy (CWO) and closing-opening wedge osteotomy (COWO) for thoracolumbar kyphosis secondary to ankylosing spondylitis. Summary of Background Data. Several surgical techniques have been used to correct the fixed thoracolumbar kyphosis caused by ankylosing spondylitis. To date, the comparison of the outcomes between CWO and COWO has not yet been addressed. Methods. According to the association with anterior edge opening or not shown on the postoperative radiographs, 64 patients were divided into 2 groups (35 patients in the CWO group and 29 patients in the COWO group). The radiographical and clinical outcomes were compared between the 2 groups, with a mean follow-up of 36 months (range, 24–84 mo). Radiographical measurements included thoracic kyphosis, lumbar lordosis, global kyphosis, sagittal vertical axis, osteotomized vertebra angle, and the height of the osteotomized vertebra. Oswestry Disability Index was evaluated at the final follow-up. Results. Thoracic kyphosis did not change significantly between postoperatively and the final follow-up in both groups. The mean corrections of lumbar lordosis, global kyphosis, sagittal vertical axis, and osteotomized vertebra angle were significantly larger in the COWO group than in the CWO group (P < 0.05). Notably, statistically significant differences (P < 0.05) were observed in the variation of height of the osteotomized vertebra (1.3 cm in the CWO group vs. 0.7 cm in the COWO group). In both groups, no patients had pseudarthrosis at the osteotomy level at the last follow-up. There was no significant difference of Oswestry Disability Index scores between the 2 groups at the final follow-up. Conclusion. Both CWO and COWO are safe and effective surgical methods for correction of thoracolumbar kyphosis. COWO can obtain larger correction and better sagittal alignment without additional neurological complications.

Increased expression of insulin-like growth factor-1 receptor is correlated with tumor metastasis and prognosis in patients with osteosarcoma.

The aim of this study was to investigate the association of insulin‐like growth factor‐1 receptor (IGF‐1R) with metastasis and prognosis of osteosarcoma patients.

A Functional SNP in BNC2 Is Associated with Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity. We previously conducted a genome-wide association study (GWAS) and detected two loci associated with AIS. To identify additional loci, we extended our GWAS by increasing the number of cohorts (2,109 affected subjects and 11,140 control subjects in total) and conducting a whole-genome imputation. Through the extended GWAS and replication studies using independent Japanese and Chinese populations, we identified a susceptibility locus on chromosome 9p22.2 (p = 2.46 × 10(-13); odds ratio = 1.21). The most significantly associated SNPs were in intron 3 of BNC2, which encodes a zinc finger transcription factor, basonuclin-2. Expression quantitative trait loci data suggested that the associated SNPs have the potential to regulate the BNC2 transcriptional activity and that the susceptibility alleles increase BNC2 expression. We identified a functional SNP, rs10738445 in BNC2, whose susceptibility allele showed both higher binding to a transcription factor, YY1 (yin and yang 1), and higher BNC2 enhancer activity than the non-susceptibility allele. BNC2 overexpression produced body curvature in developing zebrafish in a gene-dosage-dependent manner. Our results suggest that increased BNC2 expression is implicated in the etiology of AIS.

Radiological Presentations in Relation to Curve Severity in Scoliosis Associated With Syringomyelia

Background: Few radiographic guidelines are available to assist clinicians in deciding when to order magnetic resonance imaging in patients with a normal history and physical examination. Most of the recent reports on the radiographic characteristics of scoliosis are limited by a small number of patients and a shortage of large curves. The association between radiological features and the severity of scoliosis has little been elaborated. The purpose of this study is to further explore the radiological presentations in relation to curve severity in scoliosis associated with Chiari malformation and syringomyelia. Methods: A total of 87 children and adolescents were divided into 3 groups: group 1 (10 degrees ≤ Cobb angle ≤ 30 degrees), group 2 (30 degrees < Cobb angle ≤ 60 degrees), and group 3 (Cobb angle > 60 degrees). Curves were classified into typical and atypical patterns in the coronal plane, and the sagittal profile was measured. Cerebellar tonsillar descent or syrinx patterns in relation to curve severity and the frequency of atypical curves were also investigated. Results: The frequency of atypical curve patterns from groups 1 to 3 was 46.2%, 45.2%, and 40.7%, respectively. A total of 65.3% of patients with typical curve patterns had atypical features in all of the 3 groups. There was a significant difference of kyphotic angle among the 3 groups showing that the larger curves tended to have greater thoracic kyphosis. Both the degree of cerebellar tonsillar descent and syrinx patterns had no correlation with the curve severity or the frequency of atypical curves. Conclusions: These results show that radiographic presentations including atypical curve patterns, atypical features in typical curve patterns, and a normal to hyperkyphotic thoracic spine may suggest the need for a preoperative magnetic resonance imaging. Kyphosis may be indicative of progressive scoliosis. There is no evidence to suggest that the degree of cerebellar tonsillar descent and syrinx patterns have an effect on the progress of scoliosis and the frequency of atypical curves. Level of Evidence: Systematic review 2 of Level III studies.

Suppression of radiation loss by hybridization effect in two coupled split-ring resonators

This paper investigates the radiation properties of two coupled split-ring resonators (SRRs). Due to electromagnetic coupling, two hybrid magnetic plasmon modes were induced in the structure. Our calculations show that the radiation loss of the structure was greatly suppressed by the hybridization effect. This led to a remarkable increase in the Q-factor of the coupled system compared to the single SRR. By adjusting the distance between the two SRRs, the Q-factor changed correspondingly due to different electromagnetic coupling strengths. This resulted in a coupled structure that functioned as a new type of nanocavity with an adjustable Q-factor.

Radiographical predictors for postoperative sagittal imbalance in patients with thoracolumbar kyphosis secondary to ankylosing spondylitis after lumbar pedicle subtraction osteotomy.

Study Design. A retrospective radiographical study. Objective. To identify the radiographical predictors for sagittal imbalance in patients with thoracolumbar kyphosis secondary to ankylosing spondylitis (AS) after 1-level lumbar pedicle subtraction osteotomy (PSO). Summary of Background Data. Few studies had correlated the preoperative sagittal parameters with postoperative sagittal alignments to determine the radiographical predictors for postoperative sagittal imbalance in patients with AS after 1-level lumbar PSO. Methods. Thirty-six patients with thoracolumbar kyphosis secondary to AS who underwent 1-level lumbar PSO were recruited with a minimal follow-up of 24 months (mean = 27.4 mo; range, 24–53 mo). Correlation analysis and subsequent stepwise multiple regression analysis were used to evaluate the correlations between preoperative parameters, including global kyphosis, local kyphosis, thoracic kyphosis, thoracolumbar Cobb angle, lumbar lordosis, pelvic incidence (PI), pelvic tilt, sacral slope, and sagittal vertical axis (SVA), as well as SVA at the last follow-up. All these patients were further divided into 2 groups according to the PI value (group A: PI >50°; group B: PI ⩽50°). The correction outcomes were compared between these 2 groups. Results. The preoperative SVA was not significantly different between group A and group B (157.6 mm vs. 124.5 mm; P> 0.05), and both groups had similar magnitudes of kyphosis corrections at the last follow-up (global kyphosis: 42.9°vs. 46.1°; local kyphosis: 42.7°vs. 40.5°; lumbar lordosis: 35.7°vs. 43.0°). However, group A patients had significantly larger SVA at the last follow-up (73.2 mm vs. 28.7 mm; P< 0.05) and a higher incidence of postoperative sagittal imbalance (77.8% vs. 25.9%; P< 0.05) than those in group B. The stepwise multiple regression analysis demonstrated that both preoperative SVA and PI were significant independent predictors of postoperative sagittal alignments, which explained 52.0% and 9.7% of the variability of SVA at the last follow-up, respectively. Conclusion. Patients with AS with either larger preoperative SVA or larger PI are more likely to experience failed sagittal realignments after 1-level lumbar PSO. For these patients, additional osteotomies may be recommended for satisfactory correction outcomes. Level of Evidence: 4