Snowflake-inspired and blink-driven flexible piezoelectric contact lenses for effective corneal injury repair.

The cornea is a tissue susceptible to various injuries and traumas with a complicated cascade repair process, in which conserving its integrity and clarity is critical to restoring visual function. Enhancing the endogenous electric field is recognized as an effective method of accelerating corneal injury repair. However, current equipment limitations and implementation complexities hinder its widespread adoption. Here, we propose a snowflake-inspired, blink-driven flexible piezoelectric contact lens that can convert mechanical blink motions into a unidirectional pulsed electric field for direct application to moderate corneal injury repair. The device is validated on mouse and rabbit models with different relative corneal alkali burn ratios to modulate the microenvironment, alleviate stromal fibrosis, promote orderly epithelial arrangement and differentiation, and restore corneal clarity. Within an 8-day intervention, the corneal clarity of mice and rabbits improves by more than 50%, and the repair rate of mouse and rabbit corneas increases by over 52%. Mechanistically, the device intervention is advantageous in blocking growth factors' signaling pathways specifically involved in stromal fibrosis whilst preserving and harnessing the signaling pathways required for indispensable epithelial metabolism. This work put forward an efficient and orderly corneal therapeutic technology utilizing artificial endogenous-strengthened signals generated by spontaneous body activities.

Integrated Multiplex Sensing Clear Aligner for In Situ Monitoring of Dental Enamel Demineralization.

Clear aligners have become one of the most important tools in orthodontic treatment. However, over a lengthy period of orthodontic treatment, enamel demineralization or even dental caries could be susceptible for occurrence. Therefore, early diagnosis of enamel demineralization has been widely investigated. Nevertheless, for reasons including bulky monitoring equipment and complexity of operation, few techniques reported to date possessed clinical utility. The combination of flexible electronics and electrochemical sensing technology presented a promising strategy. Herein, an integrated multiplex sensing clear aligner (IMSCA) system, including a clear aligner with a multiplex sensor array patch, was developed for in situ monitoring of Ca2+, pH, and PO43- in the oral environment to provide a foundation for early diagnosis of enamel demineralization. The IMSCA exhibited a broad linear response range, great selectivity, temporal stability, reproducibility, and biological safety. Results of enamel demineralization simulating experiments and human permanent tooth demineralization experiments validate the capability of the IMSCA to indicate the occurrence of enamel demineralization. All results ultimately point to the promising clinical utility of the IMSCA, which facilitates the quantitative characterization of enamel demineralization in complex oral environments. This study provides a novel strategy in the early diagnosis of enamel demineralization.

Study on the Optimal Surgical Scheme for Very Severe Osteoporotic Vertebral Compression Fractures.

OBJECTIVE: Therapy of very severe osteoporotic compression fractures (VSOVCF) has been a growing challenge for spine surgeons. Opinions vary regarding the optimal surgical procedure for the treatment of VSOVCF and which internal fixation method is more effective is still under debate, and research on this topic is lacking. This retrospective study was conducted to compare the efficacy and safety of various pedicle screw fixation methods for treating VSOVCF. METHODS: This single-center retrospective comparative study was conducted between January 2015 and September 2020. Two hundred and one patients were divided into six groups according to different surgical methods: 45 patients underwent long-segment fixation (Group 1); 39 underwent short-segment fixation (Group 2); 30 received long-segment fixation with cement-reinforced screws (Group 3); 32 received short-segment fixation with cement-reinforced screws (Group 4); 29 had long-segment fixation combined with kyphoplasty (PKP) (Group 5); and 26 cases had short-segment fixation combined with PKP (Group 6). The clinical records were reviewed and the visual analogue scale (VAS) score and the Oswestry Disability Index (ODI) score were used for clinical evaluation. The vertebral height (VH), fractured vertebral body height (FVBH), and Cobb's angle were objectively calculated and analyzed on lateral plain radiographs. Student's t-tests and one-way ANOVA among groups were conducted to analyze the continuous, and the chi-squared test was used to compare the dichotomous or categorical variables. The difference was considered statistically significant when the P-value was less than 0.05. RESULTS: The six groups had similar distributions in age, gender, course of the disease, follow-up period, and injured level. In the postoperative assessment of the VAS score, the surgical intervention most likely to rank first in terms of pain relief was the short-segment fixation with cement-reinforced screws (Group 4). For the functional evaluation, the surgical intervention that is most likely to rank first in terms of ODI score was a short-segment fixation with cement-reinforced screws (Group 4), followed by long-segment fixation (Group 1). The long-segment fixation with cement-reinforced screws was the first-ranked surgical intervention for the maintenance of Cobb's angle and vertebral height, whereas the short-segment fixation performed the worst. The highest overall complication rate was in Group 6 with an incidence of 42.3% (11/26), followed by Group 2 with an incidence of 38.5% (15/39). CONCLUSION: For the treatment of VSOVCF, the short-segment fixation with cement-reinforced screws is the most effective and optimal procedure, and should be used as the preferred surgical method if surgeons are proficient in using cemented screws; otherwise, directly and unquestionably use long-segment fixation to achieve satisfactory clinical results.

Bone-Metabolism-Related Serum microRNAs to Diagnose Osteoporosis in Middle-Aged and Elderly Women.

Objective: Postmenopausal osteoporosis (PMOP), a chronic systemic metabolic disease prevalent in middle-aged and elderly women, heavily relies on bone mineral density (BMD) measurement as the diagnostic indicator. In this study, we investigated serum microRNAs (miRNAs) as a possible screening tool for PMOP. Methods: This investigation recruited 83 eligible participants from 795 community-dwelling postmenopausal women between June 2020 and August 2021. The miRNA expression profiles in the serum of PMOP patients were evaluated via miRNA microarray (six PMOP patients and four postmenopausal women without osteoporosis (n-PMOP) as controls). Subsequently, results were verified in independent sample sets (47 PMOP patients and 26 n-PMOP controls) using quantitative real-time PCR. In addition, the target genes and main functions of the differentially expressed miRNAs were explored by bioinformatics analysis. Results: Four highly expressed miRNAs in the serum of patients (hsa-miR-144-5p, hsa-miR-506-3p, hsa-miR-8068, and hsa-miR-6851-3p) showed acceptable disease-independent discrimination performance (area under the curve range: 0.747-0.902) in the training set and verification set, outperforming traditional bone turnover markers. Among four key miRNAs, hsa-miR-144-5p is the only one that can simultaneously predict changes in BMD in lumbar spine 1-4, total hip, and femoral neck (ß = -0.265, p = 0.022; ß = -0.301, p = 0.005; and ß = -0.324, p = 0.003, respectively). Bioinformatics analysis suggested that the differentially expressed miRNAs were targeted mainly to YY1, VIM, and YWHAE genes, which are extensively involved in bone metabolism processes. Conclusions: Bone-metabolism-related serum miRNAs, such as hsa-miR-144-5p, hsa-miR-506-3p, hsa-miR-8068, and hsa-miR-6851-3p, can be used as novel biomarkers for PMOP diagnosis independent of radiological findings and traditional bone turnover markers. Further study of these miRNAs and their target genes may provide new insights into the epigenetic regulatory mechanisms of the onset and progression of the disease.

Study on Risk Factors of Primary Non-traumatic OVCF in Chinese Elderly and a Novel Prediction Model.

OBJECTIVE: Prevention of fragility fractures is one of the public health priorities worldwide, whilst the incidence of osteoporotic vertebral compression fractures (OVCF) continues to rise and lacks the corresponding accurate prediction model. This study aimed to screen potential causes and risk factors for primary non-traumatic osteoporotic vertebral compression fractures (NTOVCF) in the elderly by characterizing a patient population with NTOVCF and comparing it with a population of osteoporotic patients. METHODS: Between January 2013 and January 2022, 208 elderly patients with unequivocal evidence of bone fragility manifested as painful NTOVCF were enrolled, and compared with 220 patients with osteoporosis and no fractures. The demographic data, bone turnover markers, blood routine, serum biochemical values, and radiological findings were investigated. Differences between the fracture and non-fracture groups were analyzed, and variables significant in univariate analysis and correlation analysis were included in the logistic analysis to build the risk prediction model for osteoporotic vertebral fractures. Univariate analysis using student's t-tests for continuous variables or a chi-squared test for categorical variables was conducted to identify risk factors. RESULTS: No significant differences were revealed regarding age, gender, BMI, smoking, alcohol consumption, blood glucose, propeptide of type I procollagen (P1NP), and N-terminal middle segment osteocalcin (N-MID) (P > 0.05). Parathyroid Hormone (PTH), 25(OH)D, serum albumin (ALB), hemoglobin (HB), bone mineral density (BMD), and cross-sectional area (CSA) of the paraspinal muscle in the fracture group were significantly lower than those in the control group; however, b-C-terminal telopeptide of type I collagen (ß-CTX), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), non-prostatic acid phosphatase (NACP), and fatty degeneration ratio (FDR) were significantly higher than those in the control group (P < 0.05). Logistic regression analysis showed that ALB, HB, CSA, and BMD were negatively correlated with NTOVCF, while ß-CTX, HDL-C, NACP, and FDR were positively correlated with NTOVCF. CONCLUSION: Decreased physical activity, anemia, hypoproteinemia, imbalances in bone metabolism, abnormal lipid metabolism, and degenerative and decreased muscle mass, were all risk factors for OVCF in the elderly, spontaneous fractures may be the consequence of cumulative declines in multiple physiological systems over the lifespan. Based on this risk model, timely detection of patients with high OVCF risk and implementation of targeted preventive measures is expected to improve the effect of fracture prevention.

Tyrosine phosphorylation tunes chemical and thermal sensitivity of TRPV2 ion channel.

Transient receptor potential vanilloid 2 (TRPV2) is a multimodal ion channel implicated in diverse physiopathological processes. Its important involvement in immune responses has been suggested such as in the macrophages' phagocytosis process. However, the endogenous signaling cascades controlling the gating of TRPV2 remain to be understood. Here, we report that enhancing tyrosine phosphorylation remarkably alters the chemical and thermal sensitivities of TRPV2 endogenously expressed in rat bone marrow-derived macrophages and dorsal root ganglia (DRG) neurons. We identify that the protein tyrosine kinase JAK1 mediates TRPV2 phosphorylation at the molecular sites Tyr(335), Tyr(471), and Tyr(525). JAK1 phosphorylation is required for maintaining TRPV2 activity and the phagocytic ability of macrophages. We further show that TRPV2 phosphorylation is dynamically balanced by protein tyrosine phosphatase non-receptor type 1 (PTPN1). PTPN1 inhibition increases TRPV2 phosphorylation, further reducing the activation temperature threshold. Our data thus unveil an intrinsic mechanism where the phosphorylation/dephosphorylation dynamic balance sets the basal chemical and thermal sensitivity of TRPV2. Targeting this pathway will aid therapeutic interventions in physiopathological contexts.

All the cells in our body have a membrane that separates their interior from the outside environment. However, studded across this barrier are numerous ion channels which allow the cell to sense and react to changes in its surroundings. This includes the ion channel TRPV2, which opens in response to mechanical pressure, certain chemical signals, or rising temperature levels. Many types of cell express TRPV2, including cells in the nervous system, muscle, and the immune system. However, despite being extensively studied, it is still not clear how TRPV2 opens and closes upon encountering high temperatures. In particular, previous work suggested that TRPV2 only responds when a cell's surroundings reach around 52°C, which is a much higher temperature than cells inside our body normally encounter, even during a fever. To help resolve this mystery, Mo, Pang et al. studied TRPV2 in neurons responsible for sending sensory information and in immune cells called macrophages which had been extracted from rodents and grown in the laboratory. They found that when the cells were bathed in solutions containing magnesium ions, their TRPV2 channels were more sensitive to a number of different cues, including temperature. Further biochemical experiments showed that magnesium ions do not directly affect TRPV2, but increase the activity of another protein called JAK1. The magnesium ions caused JAK1 to attach specialized structures called phosphorylation tags to TRPV2. This modification (known as phosphorylation) made the channel more sensitive, allowing it to open in response to temperatures as low as 40°C. Mo, Pang et al. found that inhibiting JAK1 reduced the activity of TRPV2. Conversely, inhibiting the enzyme that removes the phosphorylation tags, called PTPN1, increased the channel's activity. They also discovered that when JAK1 was blocked, macrophages were less able to 'eat up' bacteria, which is one of their main roles in the immune system. Taken together these experiments advance our understanding of how TRPV2 becomes active. The balance between the phosphorylation by JAK1 and the dephosphorylation by PTPN1 controls the temperature at which TRPV2 opens. Since TRPV2 contributes to several biological functions, including the development of the nervous system, the maintenance of heart muscles, and inflammation, these findings will be important to scientists in a broad range of fields.

Multifunctional flexible contact lens for eye health monitoring using inorganic magnetic oxide nanosheets.

As a non-invasive innovative diagnosis platform, advanced flexible contact lenses can dynamically monitor vital ocular indicators, spot abnormalities and provide biofeedback guidance for real-time diagnosis and rehabilitation tracking of chronic eye diseases. However, most of the state-of-the-art reported contact lenses either can only monitor a single indicator at a time or realize multifunctional integration based on multiple materials. Herein, we developed a flexible multifunctional contact lens based on inorganic γ-Fe2O3@NiO magnetic oxide nanosheets, which can be attached conformally and seamlessly to the eyeball to simultaneously monitor glucose level in tears, eyeball movement, and intraocular pressure. The optimized contact lens has a reliable glucose detection limit (0.43 µmol), superior eye movement measurement accuracy (95.27%) and high intraocular pressure sensitivity (0.17 MHz mmHg- 1). This work presents a concept in the biochemical and biophysical integrated sensing of ocular signals using contact lens via an innovative material, and provides a personalized and efficient way for health management.

Comprehensive bioinformatics analysis reveals the hub genes and pathways associated with multiple myeloma.

PURPOSE: While the prognosis of multiple myeloma (MM) has significantly improved over the last decade because of new treatment options, it remains incurable. Aetiological explanations and biological targets based on genomics may provide additional help for rational disease intervention. MATERIALS AND METHODS: Three microarray datasets associated with MM were downloaded from the Gene Expression Omnibus (GEO) database. GSE125364 and GSE39754 were used as the training set, and GSE13591 was used as the verification set. The differentially expressed genes (DEGs) were obtained from the training set, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to annotate their functions. The hub genes were derived from the combined results of a protein-protein interaction (PPI) network and weighted gene coexpression network analysis (WGCNA). The receiver operating characteristic (ROC) curves of hub genes were plotted to evaluate their clinical diagnostic value. Biological processes and signaling pathways associated with hub genes were explained by gene set enrichment analysis (GSEA). RESULTS: A total of 1759 DEGs were identified. GO and KEGG pathway analyses suggested that the DEGs were related to the process of protein metabolism. RPN1, SEC61A1, SPCS1, SRPR, SRPRB, SSR1 and TRAM1 were proven to have clinical diagnostic value for MM. The GSEA results suggested that the hub genes were widely involved in the N-glycan biosynthesis pathway. CONCLUSION: The hub genes identified in this study can partially explain the potential molecular mechanisms of MM and serve as candidate biomarkers for disease diagnosis.

Declining serum bone turnover markers are associated with the short-term positive change of lumbar spine bone mineral density in postmenopausal women.

OBJECTIVE: While serum bone turnover markers (BTMs) and bone mineral density (BMD) have been confirmed as useable risk assessment tools for postmenopausal osteoporosis, the associations between BTMs and BMD changes are still ambiguous. The aim of this study was to explore the underlying associations between BTMs and BMD changes in postmenopausal women. METHODS: Between January 2015 and October 2020, 135 postmenopausal women were retrospectively enrolled. They were divided into two groups according to lumbar spine (LS) 1-4 BMD change (1 y T-score minus baseline T-score, Group 1 [n = 36] < 0 and Group 2 [n = 99] ≥ 0). The changes of BTMs (N-terminal middle segment osteocalcin [N-MID], propeptide of type I procollagen [P1NP], and ß-C-terminal telopeptide of type I collagen [ß-CTX]) and their associations with LS 1-4 BMD change were analyzed. The biochemical indices and clinical parameters related with LS 1-4 BMD change were also evaluated. RESULTS: The 1 year N-MID, P1NP, ß-CTX and Phosphorus in Group 2 were lower than those in Group 1 (P < 0.05), their changes within 1 year were significantly negatively correlated with LS 1-4 BMD change (R2 = -0.200, P < 0.001; R2 = -0.230, P < 0.001; R2 = -0.186, P < 0.001; R2 = -0.044, P = 0.015; respectively). Except for the Phosphorus change (area under the curve [AUC] = 0.623), the changes of N-MID, P1NP, and ß-CTX and their 1 year levels had similar AUC to diagnose the short-term LS 1-4 BMD change (AUC > 0.7 for all, with the AUC of 1 y P1NP being the largest at 0.803). Binary logistic regression analysis showed that the physical activity and drug intervention were the determinant factors for the LS 1-4 BMD change (odds ratio = 6.856, 95% confidence interval: 2.058-22.839, P = 0.002; odds ratio  = 5.114, 95% confidence interval: 1.551-16.864, P = 0.007; respectively). CONCLUSIONS: Declining N-MID, P1NP, ß-CTX, and Phosphorus are associated with the short-term increase of LS 1-4 BMD within 1 year. Physical activity and drug intervention are factors significantly influencing the change of LS 1-4 BMD in postmenopausal women.

Identification of circRNA Expression Profiles in BMSCs from Glucocorticoid-Induced Osteoporosis Model.

BACKGROUND: Circular RNAs (circRNAs) contribute to the regulation of many diseases. However, little is known about the role of circRNAs in the development of glucocorticoid-induced osteoporosis (GIOP). The present study is aimed at systematically characterizing the circRNA expression profiles in GIOP and predict the potential functions of the associated regulatory networks. METHODS: A small animal GIOP model was developed in Sprague-Dawley rats given daily intraperitoneal doses of the synthetic glucocorticoid dexamethasone. Micro-CT and bone histomorphometry were performed to characterize the bone loss. Alizarin red S (ARS) staining and alkaline phosphatase (ALP) activity were assessed to determine the osteogenic differentiation potential of BMSCs. RNA sequencing was performed to identify differentially expressed circRNAs in BMSCs between the GIOP and normal groups, which were validated by qRT-PCR. siRNA interference experiments were used to demonstrate their function. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to predict the functions of differentially expressed circRNAs. The microRNA (miRNA) targets of the circRNAs and circRNA-miRNA interactions were predicted. RESULTS: Micro-CT and bone histomorphometry confirmed the rat GIOP model. Both ARS intensity and ALP activity were decreased in GIOP BMSCs. Seventeen circRNAs were identified by fold change = 2.0, p < 0.05, and false discovery rate < 0.05, of which 7 were upregulated and 10 were downregulated. The qRT-PCR results of the selected circRNAs were consistent with the RNA-seq results and showed that circARSB and circAKT3 were significantly upregulated, while circPTEN and circTRPM7 were downregulated in the GIOP group. Further functional experiments found that downregulation of circARSB and circPTEN expression resulted in a corresponding change in osteogenic differentiation, suggesting that circARSB negatively, while circPTEN positively, regulates BMSC osteogenic differentiation. Analysis of circRNA-targeted miRNAs predicted that miR-135a-5p was associated with circARSB and circAKT3, and miR-881-3p was associated with circPTEN and circTRPM7. Furthermore, the signalling pathways associated with these differentially expressed circRNAs were predicted. CONCLUSIONS: The present study identified circARSB, circAKT3, circPTEN, and circTRPM7 as being associated with osteogenic differentiation during GIOP through a circRNA-targeted miRNA-mRNA axis, which might provide insight into the pathophysiological mechanism of GIOP.

A programmable and skin temperature-activated electromechanical synergistic dressing for effective wound healing.

Mechanical regulation and electric stimulation hold great promise in skin tissue engineering for manipulating wound healing. However, the complexity of equipment operation and stimulation implementation remains an ongoing challenge in clinical applications. Here, we propose a programmable and skin temperature-activated electromechanical synergistic wound dressing composed of a shape memory alloy-based mechanical metamaterial for wound contraction and an antibacterial electret thin film for electric field generation. This strategy is successfully demonstrated on rats to achieve effective wound healing in as short as 4 and 8 days for linear and circular wounds, respectively, with a statistically significant over 50% improvement in wound closure rate versus the blank control group. The optimally designed electromechanical synergistic stimulation could regulate the wound microenvironment to accelerate healing metabolism, promote wound closure, and inhibit infection. This work provided an effective wound healing strategy in the context of a programmable temperature-responsive, battery-free electromechanical synergistic biomedical device.

The industrial solvent 1,4-dioxane causes hyperalgesia by targeting capsaicin receptor TRPV1.

BACKGROUND: The synthetic chemical 1,4-dioxane is used as industrial solvent, food, and care product additive. 1,4-Dioxane has been noted to influence the nervous system in long-term animal experiments and in humans, but the molecular mechanisms underlying its effects on animals were not previously known. RESULTS: Here, we report that 1,4-dioxane potentiates the capsaicin-sensitive transient receptor potential (TRP) channel TRPV1, thereby causing hyperalgesia in mouse model. This effect was abolished by CRISPR/Cas9-mediated genetic deletion of TRPV1 in sensory neurons, but enhanced under inflammatory conditions. 1,4-Dioxane lowered the temperature threshold for TRPV1 thermal activation and potentiated the channel sensitivity to agonistic stimuli. 1,3-dioxane and tetrahydrofuran which are structurally related to 1,4-dioxane also potentiated TRPV1 activation. The residue M572 in the S4-S5 linker region of TRPV1 was found to be crucial for direct activation of the channel by 1,4-dioxane and its analogs. A single residue mutation M572V abrogated the 1,4-dioxane-evoked currents while largely preserving the capsaicin responses. Our results further demonstrate that this residue exerts a gating effect through hydrophobic interactions and support the existence of discrete domains for multimodal gating of TRPV1 channel. CONCLUSIONS: Our results suggest TRPV1 is a co-receptor for 1,4-dioxane and that this accounts for its ability to dysregulate body nociceptive sensation.

Phactr1 negatively regulates bone mass by inhibiting osteogenesis and promoting adipogenesis of BMSCs via RhoA/ROCK2.

The imbalance between osteogenic and adipogenic differentiation of Bone marrow-derived mesenchymal stem cells (BMSCs) is involved in the occurrence and development of osteoporosis (OP). Previous studies have indicated the potential of phosphatase and actin regulator 1 (Phactr1) in regulating osteogenic and adipogenic differentiation of BMSCs. The present study aims to investigate the function and mechanism of Phactr1 in regulating osteogenic and adipogenic differentiation of BMSCs. Herein, the expression of Phactr1 in bone and adipose tissue of OP rats was determined by immunohistochemical. BMSCs were subjected to osteogenic and adipogenic differentiation, and transfected with Phactr1 overexpression lentivirus, small interference RNA (siRNA) and KD025 (selective ROCK2 inhibitor). The relationship between Phactr1 and ROCK2 was detected by Co-IP experiment. The expression of Phactr1, Runx2, C/EBPα, RhoA and ROCK2 was detected by Western blot. Calcium nodule and lipid droplets were determined by alizarin red and Oil red O staining. Interestingly, Phactr1 increased in both bone and adipose tissue of OP rats. During osteogenic differentiation, Phactr1 decreased and active RhoA, ROCK2 increased, while overexpression Phactr1 inhibits the increase of Runx2. Phactr1 increased and active RhoA decreased, ROCK2 did not changed during adipogenic differentiation. While, Knockdown Phactr1 inhibits the increase of C/EBPα. Phactr1 and ROCK2 were combined in osteogenic differentiation, but not in adipogenic differentiation. By using KD025, the decrease of Phactr1 and increase of Runx2 were inhibited respectively in osteogenic differentiation. Meanwhile, when ROCK2 was inhibited, Phactr1, C/EBPα were significantly increased in adipogenic differentiation. These findings indicated that Phactr1 negatively regulates bone mass by inhibiting osteogenesis and promoting adipogenesis of BMSCs by activating RhoA/ROCK2.

Comparison of Percutaneous Kyphoplasty and Pedicle Screw Fixation for Treatment of Thoracolumbar Severe Osteoporotic Vertebral Compression Fracture with Kyphosis.

BACKGROUND: Pedicle screw fixation (PSF) has been considered the preferred surgery for the treatment of severe osteoporotic vertebral compression fracture (sOVCF), and sOVCF was traditionally regarded as a relative contraindication to minimally invasive percutaneous kyphoplasty (PKP). Debate has continued regarding the selection of the best surgical method for sOVCF. In the present study, we compared the efficacy and safety between PKP and PSF. METHODS: PKP was performed in 376 patients in group 1 and PSF in 121 patients in group 2. The visual analog scale (VAS), Oswestry disability index (ODI), local kyphotic angle, fractured vertebral body height, and complications were evaluated. RESULTS: In the immediate postoperative analysis, the mean VAS score for group 1 was 2.4, significantly lower than the VAS score of 4.7 for group 2. The mean ODI score was 44.4% for group 1, lower than the ODI score of 57.1% for group 2. In addition, group 1 had had a significantly better ODI score at 1 year of follow-up. The local kyphotic angle and fractured vertebral body height had recovered better in group 2. In group 1, 113 patients had experienced cement leakage, and 29 patients had undergone PKP for adjacent new vertebral fractures. In group 2, 2 patients had developed wound infections, 4 had developed pneumonia, 2 had developed urinary tract infection, 3 had experienced asymptomatic screw loosening, and 7 had undergone PKP to treat new vertebral fractures and 1 had undergone removal of internal fixation because of back pain. CONCLUSIONS: The results of the clinical and radiological evaluations showed that PKP is comparable to PSF for the treatment of sOVCF with kyphosis, with PKP having the advantages of minimal invasion, quick postoperative pain relief, and functional recovery.

High prevalence of osteoporosis in patients undergoing spine surgery in China.

BACKGROUND: With the increase in life expectancy, a large number of patients with osteoporosis (OP) are undergoing spine surgery, which may adversely affect the surgical success rate. The prevalence of OP varies in different regions, and no data are available that represent the prevalence of OP among Chinese patients over 50 years of age who are undergoing spine surgery. It was the first multicenter study to assess OP in these patients. Aiming to obtain comprehensive data, this study combined bone mineral density (BMD) measurements and visual radiography assessment (VRA) to analyze the prevalence of OP in patients aged > 50 years who underwent spine surgery. METHODS: Data from 1,856 patients aged over 50 years undergoing spine surgery who resided in northern, central, and southern China were reviewed between 2018 and 2019. Based on the perioperative BMD and X-ray data, we calculated the prevalence of OP in this special population according to sex, age, and spine degenerative disease. RESULTS: A total of 1,245 patients (678 females and 567 males) were included in the study. The prevalence of OP diagnosed by BMD was 52.8 % in females and 18.7 % in males. When we combined with BMD and VRA, the prevalence of OP increased from 52.8 to 65.9 % in females and from 18.7 to 40.6 % in males. Although OP was more severe in females than in males, a significant difference in the rate of vertebral fracture (VF) was not observed between females and males with a normal BMD and osteopenia (females vs. males: aged 50-59 years, P = 0.977; 60-69 years, P = 0.302; >70 years, P = 0.172). Similarly, no significant difference in the vertebral fracture rate was observed within different age groups of patients with a normal BMD and osteopenia (females: P = 0.210; males, P = 0.895). The incidence of OP in patients with degenerative scoliosis was higher than that in the remaining patients (females: 63.6 % vs. 42.4 %, P = 0.018; males: 38.9 % vs. 13.8 %, P = 0.004). CONCLUSIONS: A high prevalence of OP was identified in patients aged > 50 years undergoing spine surgery, especially in patients whose primary diagnosis was degenerative scoliosis. BMD and VRA evaluations should be included in the clinical routine for these patients prior to surgery.

Effect of Teriparatide on pain relief, and quality of life in postmenopausal females with osteoporotic vertebral compression fractures, a retrospective cohort study.

BACKGROUND: Osteoporotic vertebral compression fracture (OVCF) is a common disease in elderly population, which could cause serious back pain and has a substantial impact on patients' health-related quality of life (HRQoL). The aim of this study was to identify the effect of Teriparatide as a conservative treatment on reducing back pain, and improving quality of life for postmenopausal women with osteoporotic vertebral fractures. METHODS: In a 12-month, retrospective study, 112 postmenopausal women with OVCFs were assigned to Teriparatide group (20 µg Teriparatide, subcutaneous, once daily, n=38) or control group (500 mg calcium and 400-800 IU Vitamin D per day, oral administration, n=74) according to patients' choices between January 2016 and October 2018. Patient-reported outcomes scores including the visual analogue score (VAS), Oswestry disability index (ODI), and short form 36 questionnaire (SF-36) were assessed at baseline, the 3rd months, the 6th months and 1 year after treatment. RESULTS: Treatments with Teriparatide or calcium plus vitamin D supplements had significant effect on improvement of patients' back pain as well as HRQoL, with significantly reduced VAS and ODI and increased SF-36 physical component summary (PCS) and mental component summary (MCS) scores. At the endpoint, Teriparatide showed better therapeutic effect, with greater reductions in VAS and ODI and more increases in SF-36 PCS and MCS scores. However, more adverse events (AEs) were found in Teriparatide group, but symptoms were relatively mild and of short duration. CONCLUSIONS: In postmenopausal women with OVCFs, the consequent persistent back pain and impaired HRQoL, treatment with Teriparatide was associated with more profound therapeutic effects and more AEs compared with calcium plus vitamin D supplements.

Flotillin-1 Interacts With and Sustains the Surface Levels of TRPV2 Channel.

Transient receptor potential vanilloid subtype 2 (TRPV2) channel is a polymodal receptor regulating neuronal development, cardiac function, immunity and oncogenesis. The activity of TRPV2 is regulated by the molecular interactions in the subplasmalemmel signaling complex. Here by yeast two-hybrid screening of a cDNA library of mouse dorsal root ganglia (DRG) and patch clamp electrophysiology, we identified that flotillin-1, the lipid raft-associated protein, interacts with TRPV2 channel and regulates its function. The interaction between TRPV2 and flotillin-1 was validated through co-immuoprecipitation in situ using endogenous DRG neurons and the recombinant expression model in HEK 293T cells. Fluorescent imaging and bimolecular fluorescence complementation (BiFC) further revealed that flotillin-1 and TRPV2 formed a functional complex on the cell membrane. The presence of flotillin-1 enhanced the whole-cell current density of TRPV2 via increasing its surface expression levels. Using site-specific mapping, we also uncovered that the SPFH (stomatin, prohibitin, flotillin, and HflK/C) domain of flotillin-1 interacted with TRPV2 N-termini and transmembrane domains 1-4, respectively. Our findings therefore demonstrate that flotillin-1 is a key element in TRPV2 signaling complex and modulates its cellular response.

Site-specific contacts enable distinct modes of TRPV1 regulation by the potassium channel Kvß1 subunit.

Transient receptor potential vanilloid 1 (TRPV1) channel is a multimodal receptor that is responsible for nociceptive, thermal, and mechanical sensations. However, which biomolecular partners specifically interact with TRPV1 remains to be elucidated. Here, we used cDNA library screening of genes from mouse dorsal root ganglia combined with patch-clamp electrophysiology to identify the voltage-gated potassium channel auxiliary subunit Kvß1 physically interacting with TRPV1 channel and regulating its function. The interaction was validated in situ using endogenous dorsal root ganglia neurons, as well as a recombinant expression model in HEK 293T cells. The presence of Kvß1 enhanced the expression stability of TRPV1 channels on the plasma membrane and the nociceptive current density. Surprisingly, Kvß1 interaction also shifted the temperature threshold for TRPV1 thermal activation. Using site-specific mapping, we further revealed that Kvß1 interacted with the membrane-distal domain and membrane-proximal domain of TRPV1 to regulate its membrane expression and temperature-activation threshold, respectively. Our data therefore suggest that Kvß1 is a key element in the TRPV1 signaling complex and exerts dual regulatory effects in a site-specific manner.

Gas Embolism After Hydrogen Peroxide Use During Spine Surgery: Case Report and Literature Review.

BACKGROUND: As an irrigant, an antiseptic, and a hemostatic agent, hydrogen peroxide (H2O2) is widely used in surgical treatment, but it has been surrounded by persistent controversy. Fatal or near-fatal embolic events caused by H2O2 have been reported sporadically in spine surgery. CASE DESCRIPTION: In this report, we present an 87-year-old man who underwent lumbar instrumentation removal and debridement consequent to surgical site infection in a prone position. H2O2 was used to irrigate the infected screw tracks and surrounding tissues during the procedures. Soon after irrigation, the patient suddenly developed tachycardia, hypotension, and rapid oxygen desaturation, followed by bradycardia. Transesophageal echocardiography indicated gas embolism. After prompt first aid treatment, the patient's condition improved and the gas embolus disappeared within a few minutes without any evidence of organ embolism. CONCLUSIONS: Spine surgeons should reconsider the pending results of using H2O2 during surgery. Prolonged prone positioning and semiclosed cavities may increase the risk of gas embolism. An early diagnosis and timely intervention may be the key measures to prevent the occurrence of fatal consequences caused by gas embolism.