Global Trends of the Research on Ossification of Posterior Longitudinal Ligament in Thoracic Spine: A Bibliometric and Visualization Study.

OBJECTIVE: Thoracic ossification of the posterior longitudinal ligament (TOPLL) is a rare but intractable disease, and is the second leading cause of thoracic myelopathy. This study aimed to illustrate the overall knowledge structure and development trends of TOPLL, using a bibliometric analysis and newly developed visualization tools. METHODS: Research data sets were acquired from the Web of Science. The literature search was also limited to articles that were published until October 30, 2021. VOS viewer and Citespace software was provided to analyze the data and generate visualization knowledge maps. Annual trend of publications, distribution, H-Index status, co-authorship status, and research hotspots were analyzed. RESULTS: A total of 206 publications met the requirement. Japan published most papers (92), both total citations (1574) and H-index (24) ranked first of all the countries. The most productive organization was Peking University (22). The most productive author was Yamazaki M (18). The most productive journal was Spine (33). Diagnosis and treatment on the accuracy of surgical segments, prognosis of patients, and gene research were the research hotspots in the recent years. CONCLUSIONS: The study showed an upward trend with a stable rise in recent years. Japan is country with the highest productivity, not only in quality, but also in quantity. Peking University and Spine have been the largest contributors. Indeed, this study provides great insights to the growth and development of TOPLL. Moreover, it will contribute to the growth of the international frontier.

Risk factor analysis of pulmonary cement embolism during percutaneous vertebroplasty or kyphoplasty for osteoporotic vertebral compression fractures.

OBJECTIVE: The purpose of this research is to evaluate the risk factors and incidence of pulmonary cement embolism (PCE) during percutaneous vertebroplasty (PVP) or kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCFs) based on postoperative computed tomography (CT). METHODS: A total of 2344 patients who underwent PVP or PKP due to OVCFs in our spine center were analyzed retrospectively. According to the detection of postoperative pulmonary CT, the patients were divided into two groups: pulmonary cement embolism group (PCE group) and non-pulmonary cement embolism group (NPCE group). Demographic data in both groups were compared using the χ2 test for qualitative data and the unpaired t test for quantitative data. Multiple logistic regression analysis was carried out to identify risk factors that were significantly related to the PCE resulting from cement leakage. RESULTS: PCE was found in 34 patients (1.9% 34/1782) with pulmonary CT examination after operation. There was no statistically significant difference in the parameters such as age, gender, body mass index (BMI), and cement volume in the two groups. Patients with three or more involved vertebrae had a significantly increased risk to suffer from PCE than those with one involved vertebra (p=0.046 OR 2.412 [95% CI 1.017-5.722]). Patients who suffered thoracic fracture had a significantly increased risk to suffer from PCE than those who suffered thoracolumbar fracture (p=0.001 OR 0.241 [95% CI 0.105-0.550]). And significantly increased PCE risk also was observed in thoracic fracture compared with lumbar fracture patients (p=0.028 OR 0.094 [95% CI 0.114-0.779]). The risk of PCE within 2 weeks after fracture was significantly higher than that after 2 weeks of fracture (p=0.000 OR 0.178 [95% CI 0.074-0.429]). Patients who underwent PVP surgery had a significantly increased PCE risk than those who underwent PKP surgery (p=0.001 OR 0.187 [95% CI 0.069-0.509]). CONCLUSION: The real incidence of PCE is underestimated due to the lack of routine postoperative pulmonary imaging examination. The number of involved vertebrae, fracture location, operation timing, and operation methods are independent risk factors for PCE.

Selenium donors inhibits osteoclastogenesis through inhibiting IL-6 and plays a pivotal role in bone metastasis from breast cancer.

Bone metastases are a frequent complication of breast cancer, and there has been little progress in the treatment of breast cancer patients with bone metastases. The cytotoxicity of selenium donors, including organic selenium and selenium nanoparticles (SeNPs), to cancer cells has been reported previously, but their relationship with bone metastases progression is not fully clear yet. In this study, multicenter clinical exploration was conducted to obtain dietary selenium intakes of breast cancer patients with or without bone metastasis, to study the relationship between selenium and breast cancer prognosis and bone metastasis. We found that dietary selenium intakes were significantly lower in breast cancer patients with bone metastasis, comparing with the non-bone metastasis cases. Selenium lower group of bone metastasis breast cancer patients had worse prognosis, whereas the daily selenium intakes could not predict the prognosis of breast cancer patients without bone metastasis. Subsequently, we study the regulatory role of selenium donors on bone metastasis at the cellular level, by challenging the cells with SeNPs. SeNPs showed potent cytotoxicity in breast cancer cells, no matter whether they were primary or bone-metastatic. SeNPs treated cancer cell inhibited the survival and differentiation of osteoclast progenitor cells. At the molecular level, we demonstrated that IL-6 partially mediated osteoclastogenesis suppression by SeNPs. These results provide a new way for biomarkers or drug development to treat and even prevent bone metastases of breast cancer by using selenium donors.

Percutaneous Vertebroplasty with Side-Opening Cannula or Front-Opening Cannula in the Treatment of Kummell Disease?

OBJECTIVE: To explore the effect of bone cement distribution, cement leakage, and clinical outcomes with side-opening cannula for bone cement injection in percutaneous vertebroplasty (PVP) in treatment of Kummell disease. METHODS: A prospective study of patients with Kummell disease undergoing PVP was conducted from April 2012 to September 2017. In total, 43 patients (11 males, 32 females) with Kummell disease who received bilateral PVP were included in the study. The patients were divided into front-opening cannulas (FOC) group with front-opening cannulas and side-opening cannulas (SOC) group with side-opening cannulas. All patients were followed up for 6 months. The patient general information such as gender, age, bone density, compression ratio, operative time, and location of fracture vertebrae were recorded. Visual analogue scale (VAS), Oswestry Disability Index (ODI), bone cement distribution, radiation exposure time, bone cement leakage rate and vertebral height, and kyphosis angle were measured and compared for two groups before surgery, 1 day and 6 months after surgery. RESULTS: A total of 43 patients were enrolled, including 11 males and 32 females, aged 61-84 years. The bone density (T value) was 2.5 ± 0.6 in FOC group and 2.4 ± 0.6 in SOC group (P > 0.05). The compression ratio and operative time were 36.1% ± 13.0%, 39.3 ± 7.9 min in FOC group and 35.2% ± 13.7%, 40.0 ± 10.7 min in SOC group (P > 0.05). There was no significance between FOC and SOC groups in the location of fracture vertebrae. All patients underwent at least 6 months of follow-up. At 6 months postoperatively, the VAS and ODI were significantly higher in the FOC group (3.0 ± 0.8, 35.7% ± 2.1%) than in the SOC group (1.3 ± 0.4, 18.6% ± 2.4%) (P < 0.05). The cement leakage rate of the SOC group was 4.8%, which was lower than that of the FOC group (31.8%, P < 0.05), and the bone cement distribution ratio was higher than that of the FOC group (63.1% ± 7.9% vs 40.5% ± 8.6%, P < 0.05). At 6 months after operation, the height of the anterior and posterior vertebral bodies of the patients in the SOC group restored better than the FOC group (anterior SOC: FOC 5.1 ± 0.5 mm vs 4.5 ± 0.5 mm; posterior SOC: FOC 0.6 ± 0.1 mm vs 0.3 ± 0.1 mm, P < 0.05), and the kyphosis correction was more obvious than patients in FOC group (SOC: FOC 8.5° ± 1.4° vs 4.6° ± 0.8°, P < 0.05). CONCLUSION: Percutaneous vertebroplasty with side-opening cannula is safe and effective in avoiding bone cement leakage, improving bone cement distribution, and restoring vertebral height.

Research Advances of Prevention and Control of Hydrogen Sulfide in Coal Mines.

Sudden emission and casualty accidents caused by abnormal enrichment of hydrogen sulfide (H2S) in coal mines are becoming frequent increasingly, causing major casualties and environmental pollution. Scholars in various countries have developed various measuring devices for hydrogen sulfide content in coal and rock formations and their calculation methods. The existing prevention and control technologies of H2S in coal mines were summarized in various countries. According to the distribution characteristics, occurrence modes, and emission forms of H2S in coal mines, the prevention and control technologies of H2S in coal-bearing strata, airflow in tunnel, and underground water body are mainly introduced. Analyzed the effects of different ventilation systems on prevention and control of H2S, which include conventional ventilation system, partial homotropal ventilation system, and full homotropal ventilation system. The methods used mainly include neutralization by injecting alkalizer through drilling in coal seams with high pressure, spraying alkalizer in tunnel, attenuation by increasing wind amount, changing the ventilation method, pumping, dredging, and blocking the water that contains H2S as well as comprehensive prevention and control method. The basic agents adopted mainly include sodium carbonate (the mass percentage concentration is about 0.5% ~ 3.0%) and sodium bicarbonate solution, and some basic solution is added by an additive, such as surfactant, Fenton reagent, sodium dodecyl benzene sulfonate, sodium hypochlorite, or chloramine-T. The treatment effect and the main problems of each prevention and control technology are analyzed, and a comprehensive method of prevention and control techniques of H2S in coal mines is proposed. According to current technological level as well as the cost, the effective prevention and control techniques of H2S should take the occurrence, distribution, and emission forms of H2S in coal mines as well as the content into consideration.

Downregulation of microRNA­660 inhibits cell proliferation and invasion in osteosarcoma by directly targeting forkhead box O1.

The abnormal expression of microRNAs (miRNAs/miRs) has been observed in osteosarcoma (OS), and these differently expressed miRNAs contribute to the occurrence and development of OS by regulating various biological behaviours. Therefore, a comprehensive understanding of the detailed roles of aberrantly expressed miRNAs in OS progression may be favourable to the identification of promising therapeutic strategies for the treatment of patients with this malignancy. The present study demonstrated that miR­660­5p (miR­660) expression was significantly upregulated in OS tissues and cell lines compared with that in normal adjacent tissues and normal human osteoblast hFOB1.19, respectively. miR­660 downregulation led to a significant decrease in the proliferation and invasion of OS cells. Forkhead box O1 (FOXO1) was predicted as a potential target of miR­660. The subsequent luciferase reporter assay indicated that miR­660 directly binds to the 3'­untranslated region of FOXO1. Furthermore, miR­660 inhibition increased the FOXO1 expression in OS cells at mRNA and protein levels. Moreover, FOXO1 was downregulated in OS tissues and this downregulation was negatively correlated with miR­660 levels. Besides, rescue experiments demonstrated that FOXO1 knockdown abolished the effects of miR­660 knockdown on OS cell proliferation and invasion. These results suggest that miR­660 may serve oncogenic roles in OS by directly targeting FOXO1. Targeting miR­660 may be an effective candidate for the treatment of patients with OS.

Increased expression of TIPE2 mRNA in PBMCs of patients with ankylosing spondylitis is negatively associated with the disease severity.

Ankylosing spondylitis (AS) is an autoimmune disease and characterized by chronic inflammatory arthritis. Tumor necrosis factor α induced protein-8 like-2 (TIPE2) is responsible for maintaining immune homeostasis by inhibiting the secretion of inflammatory cytokines in the condition of inflammation. However, whether TIPE2 participates in the development of AS remains unknown. In this study, we measured the mRNA expression of TIPE2 and TIPE1 in peripheral blood mononuclear cells (PBMCs) from 45 AS patients and 40 healthy controls by qRT-PCR. The results showed TIPE2 expression was significantly increased in AS patients compared with controls (P=0.0066), while there was no significant difference for TIPE1 between two groups (P=0.2302). Moreover, the expression of TIPE2 mRNA in AS patients were decreased after treatment with TNF-α blocker (P<0.001). In addition, we found that TNF-α or plasma from AS patients induced TIPE2 expression in THP-1 cells in vitro. More importantly, the TIPE2 mRNA expression levels were negatively correlated with TNF-α, hsCRP and bath ankylosing spondylitis disease activity index (BASDAI) (r=-0.3574, P=0.0159; r=-0.3174, P=0.0336; r=-0.6000, P<0.0001; respectively) in the AS patients. These results indicated that TIPE2 contributes to the pathogenesis of AS.