Preoperative Range of Motion in Extension May Influence Postoperative Cervical Kyphosis After Laminoplasty.

STUDY DESIGN: Retrospective observational study. OBJECTIVE: The objective of this study was to investigate factors associated with cervical kyphosis after laminoplasty. SUMMARY OF BACKGROUND DATA: Many factors are reportedly associated with the deterioration of cervical curvature after laminoplasty, including cervical lordosis angle, cervical spine range of motion (ROM), T1 slope, and C2-C7 sagittal vertical axis. Postlaminoplasty kyphosis or deterioration of cervical curvature is likely caused by multiple factors. There is currently no consensus on these issues. MATERIALS AND METHODS: Data of patients treated with laminoplasty for degenerative cervical myelopathy at our institution during 2008-2018 were reviewed. The following variables were collected for each patient: age and sex; follow-up time; surgery involving C3 (yes or no); surgery involving C7 (yes or no); distribution of segments operated on; number of laminae operated on; flexion, extension, and total ROM; cervical lordotic angle; longitudinal distance index; curvature index; C2-C7 sagittal vertical axis; and T1 slope. Logistic regression analysis was used to assess possible risk factors for postoperative kyphosis. Receiver operating characteristic curves were constructed to determine the cutoff values of risk factors. RESULTS: The study cohort comprised 151 patients. Logistic regression analysis indicated that sex, number of laminae operated on, and preoperative extension ROM were significantly associated with postoperative cervical kyphosis ( P <0.05). There was significantly greater postoperative kyphosis in women than in men; the more segments operated on, the greater the risk of postoperative kyphosis, and the larger the preoperative extension ROM, the lower the risk of postlaminoplasty kyphosis. Receiver operating characteristic curve analysis showed that the cutoff value for preoperative extension ROM is 22.1°. CONCLUSIONS: Preoperative extension ROM may be associated with the development of postoperative kyphosis. The cutoff value of preoperative extension ROM that suggested the prospect of postoperative kyphosis in our sample was 22.1°.

A Rare Heterozygous TINF2 Deletional Frameshift Mutation in a Chinese Pedigree With a Spectrum of TBDs Phenotypes.

Telomere biology disorders (TBDs) induced by TINF2 mutations manifest clinically with a spectrum of phenotypes, from silent carriers to a set of overlapping conditions. A rare TINF2 frameshift mutation (c.591delG) encoding a truncated mutant TIN2 protein (p.W198fs) was identified in a 6-years-and-3-month-old Chinese girl with neuroblastoma (NB) by next generation sequencing and confirmed by Sanger sequencing. To explore the possible implications of TINF2 mutations in TBDs development, the TINF2 mutant was transfected into the human embryonic kidney (HEK) 293T cells, and mRNA expression of the shelterin complex components as well as the cellular distribution of mutant TIN2 were examined. The TINF2 mutation was phenotypically associated with short stature in the proband, nail dystrophy and spotted hypopigmentation in her mother, and psoriasis in her older brother. I-TASSER modeling analysis revealed conformational changes of the mutant TIN2 protein and loss of pivotal domains downstream of the 198th amino acid. Additionally, mRNA expression of the shelterin components was downregulated, and TIN2 mutant protein expression was reduced in HEK293T cells transfected with mutant TINF2. Furthermore, instead of being restricted to the nucleus, the mutant TIN2 was identified in both the cytoplasm and the nucleus. The TINF2 gene mutation might impair the function of the shelterin complex and the telomere maintenance mechanisms, both of which are involved in the development of TBDs. TBDs have been associated with increased cancer risk. To the best of our knowledge, this is the first report of NB in patients with TBDs. The relationship between the TINF2 mutation and NB may need to further study.

First Report of Watermelon mosaic virus causing a Mosaic Disease on Cucumis metuliferus in China.

Cucumis metuliferus, also called horned cucumber or jelly melon, is considered as a wild species in the Cucumis genus and a potential material for nematodes- or viruses-resistant breeding (Provvidenti, et al. 1977; Sigüenza et al. 2005; Chen et al. 2020). This species, originating from Africa, has been cultivated as a fruit in China in recent years. In July 2020, a mosaic disease was observed on C. metuliferus growing in five fields (approximately 0.7 hectare) in Urumqi, Xijiang, China, where more than 85~100% of the field plants exhibited moderate to severe viral disease-like leaf mosaic and/or deformation symptoms. Delayed flowering and small and/or deformed fruits on the affected plants could result in yield loss of about 50%. To identify the causal pathogen, the symptomatic leaf samples were collected from the five fields (five plants/points for each field) and their total RNAs were extracted using a commercial RNA extraction kit. The universal potyviral primers (Ha et al. 2008) and specific primers for a number of frequently-occurring, cucurbit crop-infecting viruses including Papaya ringspot virus (PRSV) (Lin et al. 2013), Cucumber mosaic virus (CMV) and Watermelon mosaic virus (WMV) were designed and used for detection by RT-PCR. The result showed that only the WMV primers (forward: 5'-AAGTGTGACCAAGCTTGGACTGCA-3' and reverse: 5'-CTCACCCATTGTGCCAAAGAACGT-3') could amplify the corresponding target fragment from the total RNA templates, and direct sequencing of the RT-PCR products and GenBank BLAST confirmed the presence of WMV (genus Potyvirus) in the collected C. metuliferus samples. To complete Koch's postulates, the infected C. metuliferus leaves were ground in the sodium phosphate buffer (0.01 M, pH 7.0) and the sap was mechanically inoculated onto 30 four-leaf-stage C. metuliferus seedlings (two leaves for each seedling were inoculated) kept in an insect-proof, temperature-controlled greenhouse at 25~28℃. Twenty-five of the inoculated plants were observed to have apparent leaf mosaic similar to the field symptoms two weeks after inoculation, and positive result was obtained in RT-PCR detection for the symptomatic leaves of inoculated plants using the WMV primers aforementioned, confirming the virus as the pathogen of C. metuliferus in Urumqi. To our knowledge, this is the first report of WMV naturally infecting C. metuliferus in China. We obtained the full-length sequence of the WMV Urumqi isolation (WMV-Urumqi) by sequencing the RT-PCR amplicons from seven pairs of primers spanning the viral genome and the 5'RACE and 3'RACE products. The complete sequence of WMV-Urumqi (GenBank accession no. MW345911) is 10046 nucleotides (nt) long and contains an open reading frame that encodes a polyprotein of 3220 amino acids (aa). WMV-Urumqi shares the highest nt identity (95.9%) and aa identity (98.0%) with the Cucurbita pepo-infecting isolation (KX664483) from Shanxi province, China. Our findings provide a better understanding of the host range and genetic diversity of WMV, and a useful reference for virus-resistant breeding involving C. metuliferus.

How the clinical dosage of bone cement biomechanically affects adjacent vertebrae.

OBJECTIVE: This study evaluated the biomechanical changes in the adjacent vertebrae under a physiological load (500 N) when the clinically relevant amount of bone cement was injected into fractured cadaver vertebral bodies. METHODS: The embalmed cadaver thoracolumbar specimens in which each vertebral body (T12-L2) had a BMD of < 0.75 g/cm2 were used for the experiment. For establishing a fracture model, the upper one third of the L1 vertebra was performed wedge osteotomy and the superior endplate was kept complete. Stiffness of specimens was measured in different states. Strain of the adjacent vertebral body and intervertebral disc were measured in pre-fracture, post-fracture, and after augmentation by non-contact optical strain measurement system. RESULTS: The average amount of bone cement was 4.4 ml (3.8-5.0 ml). The stiffness of after augmentation was significantly higher than the stiffness of post-fracture (p < 0.05), but still lower than pre-fracture stiffness (p < 0.05). After augmentation, the adjacent upper vertebral strain showed no significant difference (p > 0.05) with pre-fracture, while the strain of adjacent lower vertebral body was significantly higher than that before fracture (p < 0.05). In flexion, T12/L1 intervertebral disc strain was significantly greater after augmentation than after the fracture (p < 0.05), but there was no significant difference from that before the fracture (p > 0.05); L1/2 vertebral strain after augmentation was significantly less than that after the fracture (p < 0.05), but there was no significant difference from that before the fracture (p > 0.05). CONCLUSIONS: PVP may therefore have partially reversed the abnormal strain state of adjacent vertebral bodies which was caused by fracture.

Is Short Same-Segment Fixation Really Better than Short-Segment Posterior Fixation in the Treatment of Thoracolumbar Fractures?

STUDY DESIGN: A retrospective study. OBJECTIVE: This retrospective study assessed whether short same-segment fixation (SSSF) is better than short-segment posterior fixation (SSPF) for reducing thoracolumbar fractures, improving the kyphosis angle, maintaining vertebral height, or reducing the incidence of broken screws. SUMMARY OF BACKGROUND DATA: In clinical practice, single-segment thoracolumbar fractures were then more likely to be treated with SSPF that included pedicle fixation at the level of the fracture (short same-segment fixation, or SSSF). Whether SSSF could really achieve vertebral height recovery, improve the kyphosis, reduce postoperative kyphosis loss, and reduce the incidence of internal fixation failure better than SSPF. METHODS: Patients treated with SSPF or SSSF at our institution during 2006 to 2014 were reviewed. Effects of thoracolumbar fracture reduction, improved kyphosis angle, and maintaining vertebral height were compared between groups. Logistic regression analysis was used to identify factors related to instrumentation breakage and correlation analysis to assess possible relations between loss of correction of the kyphosis angle (LAWAC) and other factors. RESULTS: Altogether, 130 patients were enrolled (53 SSPF, 77 SSSF). SSPF (22F, 31M) group's mean (range) age was 37.7 (16-60) years, and the follow-up was 26.2 (9-120) months. SSSF (27F, 50M) group's mean (range) age was 39.3 (17-61) years, and the follow-up was 23.2 (9-60) months. All patients underwent either internal fixation or screw repair. Immediately postoperatively, restoration after middle vertebral fractures was better in SSSF patients than in SSPF patients (P = 0.003), with no differences in other fracture-related factors (P > 0.05). Only LAWAC was significantly associated with instrumentation breakage (P < 0.05). Also, immediately postoperatively, the anterior/posterior vertebral heights ratio was negatively related to LAWAC. CONCLUSION: Pedicle fixation of the fracture did not obtain better recovery of anterior or posterior vertebral heights nor did it improve AWA restoration. There was no significant difference in LAWAC between groups or in the incidence of broken screws. LAWAC may increase the incidence of broken screws. LEVEL OF EVIDENCE: 4.

Is duration of preoperative anti-tuberculosis treatment a risk factor for postoperative relapse or non-healing of spinal tuberculosis?

PURPOSE: This study evaluated the relationship between spinal TB postoperative recurrence or non-healing and duration of preoperative anti-TB treatment (ATT). METHODS: From January 2004 to January 2013, patients who underwent surgery for spinal TB and met this study's inclusion criteria were retrospectively reviewed. Observed parameters were age, sex, initial ESR, preoperative ESR, degree of ESR change, initial CRP, preoperative CRP, degree of CRP change, duration of preoperative ATT, surgical approach, presence of internal fixation, location of spinal lesion, number of involved segments, duration of operation, and intraoperative blood loss. The data were analyzed by univariate and multivariate analyses for spinal TB recurrence or non-healing to determine related risk factors. RESULTS: A total of 223 patients met the inclusion criteria. There were 84 female and 139 male patients with a mean age of 42.2 years (range 2-85 years). The follow-up period was 18-72 months (average 28.7 months). Among 223 patients observed, 23 patients had postoperative relapse or non-healing (10.3 %) during the follow-up period. Statistical analysis indicated that the location of a spinal lesion was significantly associated with postoperative relapse or non-healing. Risk of postoperative relapse or non-healing in thoracolumbar TB was 2.524-fold (95 % CI 1.026-6.580) that of lumbosacral TB. CONCLUSIONS: Duration of preoperative ATT may not be a risk factor for postoperative recurrence or non-healing of spinal TB. Junctional zones such as the lumbosacral and thoracolumbar junction have a higher recurrence rate than non junctional.

[Establishment of a rabbit model of scoliosis induced by asymmetric load using springs].

OBJECTIVE: To establish rabbit model of scoliosis induced with stable asymmetric lumbar loads. METHODS: Scoliosis was induced in 10 two-month-old New Zealand rabbits using 316L stainless steel springs placed between the unilateral transverse processes of L2 and L5. Serial radiographs were documented before and at 1, 4, 8, 9 and 12 weeks after the operation. At weeks, the rabbits were randomly divided into SR group (n=5) with the spring removed and SK group (n=5) without spring removal. RESULTS: All the rabbits survived the experiment with Cobb angle all greater than 10 degree at the end of the experiment. Significant changes were found in the Cobb angles and kyphotic angles at 1, 4 and 8 weeks after the operation (P<0.05). At 8 weeks, the Cobb angle, the kyphotic angle and the length of the spring were similar between SR and SK groups (P>0.05), and in the 4 weeks following spring removal in SR group, the Cobb angle and the kyphosis decreased significantly compared with those in SK group (P<0.05). Micro-CT showed that the BV/TV of the concave side was greater than that of the convex side. The length of the spring did not show obvious changes during the experiment (P>0.05). CONCLUSIONS: Asymmetric lumbar loading is a convenient, time-saving, and highly reproducible approach for establishing rabbit models of scoliosis.

Multiple effects of IL-21 on human NK cells in ex vivo expansion.

Natural killer (NK) cells (CD56(+)CD3(-)) are large, granular immunocytes that play a very pivotal role in the anti-inflammatory response and tumor surveillance. As an ideal cytotoxic lymphocyte (CTL), NK cells have attracted much attention in clinical trials. However, an insufficient number and their limited life span are bottlenecks that limit the application of NK cells in adoptive immunotherapy. Interleukins such as IL-2, IL-15 and IL-18 are recognized as factors that stimulate NK cells and have been used in NK cells ex vivo expansion. Similar to IL-2 and IL-15, IL-21 is a common γ-chain cytokine that is important in NK cell activation, maturation and proliferation. The present study aims to assess the effects of membrane-bound and soluble IL-21 on primary human NK cells during ex vivo expansion. IL-21 was found to have multiple effects on NK cells, increasing their cytotoxicity in a concentration-dependent manner by up-regulating IFN-γ and Granzyme-B expression. Nevertheless, at a high concentration (50 ng/mL), IL-21 curtailed the life span of NK cells by significantly inducing apoptosis. Moreover, when treated with IL-21, the number of NKT (CD56(+)CD3(+)) cells increased among peripheral blood mononuclear cells (PBMCs) during ex vivo expansion in a concentration-dependent manner. IL-21 also promoted expanded cells to enter into S phase of the cell cycle during the first to second weeks of culture. All these results suggest that IL-21 has multiple effects on NK cell development and functions. More attention should be given to the dosage and multiple effects of IL-21 when it was applied to NK cells in ex vivo expansion.

Risk factors of new symptomatic vertebral compression fractures in osteoporotic patients undergone percutaneous vertebroplasty.

PURPOSE: This study evaluated the risk factors of new vertebral compression fractures (VCFs) following percutaneous vertebroplasty (PVP). METHODS: From June 2005 to January 2011, patients with osteoporotic VCFs (OVCFs) who were treated with PVP and met this study's inclusion criteria were retrospectively reviewed. Observed parameters were age, sex, bone mineral density, body mass index, amount of bone cement, cement leakage into the disk, preoperative kyphosis, preoperative degree of anterior vertebral compression, preoperative degree of middle vertebral compression, kyphosis correction, anterior vertebral height restoration, middle vertebral height restoration, and number of initial symptomatic fractures (levels treated). The data were analyzed by univariate and multivariate analysis for the emergence of new fractures after PVP to determine related risk factors. RESULTS: A total of 182 patients met the inclusion criteria. There were 155 female and 27 male patients with a mean age of 69.7 years (range 49-91 years). The follow-up period was 24-50 months (average 26.4 months). A total of 294 VCFs among 182 patients were observed, 28 new VCFs occurred in 21 patients (21/182, 11.5 %) during the follow-up period. Statistical analysis indicated that higher BMI (P = 0.004) and a greater number of initial symptomatic fractures (P = 0.017) were significantly associated with new VCFs after PVP. It is the most obvious that the risk of new fractures increased 2.518-fold (95 % CI 1.176-5.395), when the number of initial VCFs increased by one level. CONCLUSIONS: The incidence of new symptomatic VCFs after PVP was higher in osteoporotic patients with initial multiple-level fractures.