Vertebroplasty is a common and effective treatment for symptomatic osteoporotic vertebral compression fractures. However, the cemented and adjacent vertebras have a risk of recollapse due to largely unassured mechanisms, among which excessive stiffness of bone cement may be an important risk factor. This study aimed to find the most appropriate range of bone cement stiffness by analyzing its biomechanical effects on the augmented and adjacent vertebras of individual patient after vertebroplasty. A three-dimensional finite element model of T11-L1 osteoligamentous vertebras was reconstructed according to individual computed tomography data and validated by post mortem human subject experiment in literatures. Bone cement of varying stiffness was injected into the trabecular core of the T12 vertebra simulatively. The maximum von Mises stresses on cancellous and cortical bones of T11-L1 vertebras were analyzed under the loading conditions of flexion, extension, bending, and torsion. For the adjacent T11 and L1 vertebras, the stepwise elevation of the bone cement elastic modulus increased the maximum von Mises stress on the cancellous bone, but its effect on cortical bone was negligible. For the augmented T12 vertebra, the stresses on cancellous bone increased slightly under the loading condition of lateral bending and remained no impact on cortical bone. The linear interpolation revealed that the most suitable range of cement elastic modulus is 833.1 and 1408.1 Mpa for this patient. Increased elastic modulus of bone cement may lead to a growing risk of recollapse for the cemented vertebra as well as the adjacent vertebras. Our study provides a fresh perspective in clinical optimization of individual therapy in vertebroplasty.
Objective: In this study, we first performed a meta-analysis to assess the role of single-nucleotide polymorphism (SNP) within tumor necrosis factor alpha (TNF alpha) gene and TNF alpha expression in the risk of nasal polyposis.
Methods: STATA 12.0 software was utilized to conduct the Mantel–Haenszel statistics, Cohen statistics, Begg’s test, Egger’s tests and sensitivity analysis.
Results: We systemically carried out the database retrieval and initially identified 486 articles. After screening, 15 articles were included in our meta-analysis. For TNF alpha rs1800629 G/A SNP, compared with control group, an increased risk of nasal polyposis of case group was observed in the models of A vs. G [p (P value of association) = 0.009, OR (odds ratio) = 1.35], GA vs. GG (p = 0.001, OR = 1.69), GA+AA vs. GG (p = 0.010, OR = 1.47). The similar results were observed in Caucasian subgroup (p < 0.05, OR > 1). For TNF alpha rs361525 G/A SNP, no significant difference between control and case group was detected (all p > 0.05). In addition, a significant difference exists between case and control groups in the meta-analyses of TNF alpha expression in nasal mucosal cells, secreted TNF alpha (p < 0.05, OR > 1), but not serum TNF alpha (p = 0.090).
Conclusion: The present meta-analysis revealed that TNF alpha rs1800629, increased TNF alpha expression and secretion of nasal mucosal cells were associated with an increased risk of nasal polyposis. 相似文献
Polysaccharides are one of many bioactive compounds found in edible mushrooms. Edible mushrooms have become attractive as “health foods” and as source materials for immunomodulators. The aim of this project was to study the immunoregulatory effects of a purified polysaccharide derived from wild Russula griseocarnosa (PRG1-1) on macrophages. Our data showed that in RAW264.7 macrophage cells, PRG1-1 increased expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, PRG1-1 increased the production of nitric oxide (NO) and cytokines, including interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α). Western blotting demonstrated that the regulation of NO and cytokines was mediated through the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signalling pathways. Therefore, PRG1-1 has the capacity to activate macrophages via the NF-κB and MAPK pathways. These findings helped to elucidate the immune-modulatory properties of the polysaccharide from R. griseocarnosa. 相似文献
The maize B chromosome typically undergoes nondisjunction during the second microspore division. For normal A chromosomes, the r-X1 deficiency in maize can induce nondisjunction during the second megaspore and first microspore divisions. However, it is not known whether the r-X1 deficiency also induces nondisjunction of the maize B chromosome during these cell divisions. To answer this question, chromosome numbers were determined in the progeny of r-X1/R-r female parents carrying two B chromosomes. Some of the r-X1-lacking progeny (21.2%) contained zero or two B chromosomes. However, a much higher percentage of the r-X1-containing progeny (43.4%) exhibited zero or two B chromosomes, but none displayed more than two B chromosomes. Thus, the results indicated that the r-X1 deficiency could also induce nondisjunction of the B chromosome during the second megaspore division; moreover, the B chromosome in itself could undergo nondisjunction during the same division. In addition, pollen grains from plants with two B chromosomes lacking or exhibiting the r-X1 deficiency were compared via pollen fluorescence in situ hybridization (FISH) using a B chromosome-specific probe. The results revealed that the r-X1 deficiency could induce the occurrence of B chromosome nondisjunction during the first microspore division and that the B chromosome in itself could undergo nondisjunction during the same division at a lower frequency. Our data shed more light on the behavior of the maize B chromosome during cell division. 相似文献
This study aimed to describe the technique details of rapid pore cranial drilling with external ventricular drainage and document its clinical outcomes by highlighting the advantages over the traditional and modified cranial drilling technique. Intraventricular hemorrhage is one of the most severe subtypes of hemorrhagic stroke with high mortality. The amount of blood in the ventricles is associated with severity of outcomes, and fast removal of the blood clot is the key to a good prognosis. Between 1977 and 2013, 3773 patients admitted for intraventricular hemorrhage underwent rapid pore cranial drilling drainage. The therapeutic effects and clinical outcomes were retrospectively analyzed. Of these patients, 1049 (27.8%) experienced complete remission, 1788 (47.4%) had improved condition, and 936 (24.8%) died. A total of 3229 (85.6%) patients gained immediate remission. One typical case was illustrated to demonstrate the efficacy of the rapid pore drilling technique. Rapid pore cranial drilling drainage in patients with intraventricular hemorrhage is fast, effective, and provides immediate relief in patients with severe conditions. It could be a better alternative to the conventional drilling approach for treatment of intraventricular hemorrhage. A randomized controlled trial for direct comparison between the rapid pore cranial drilling drainage and conventional drilling technique is in urgent need.Key words: Intraventricular hemorrhage, External ventricular drainage, Rapid pore cranial drillingIntraventricular hemorrhage (IVH) denotes a bleeding within the ventricular system of the brain. It usually results from traumatic brain injuries or hemorrhagic stroke, and the prognosis can be very poor.1,2 Volume of IVH has been reported to be a predictor of outcome in patients with spontaneous intracerebral hemorrhage (ICH) and extension to the ventricles.3,4 Epidemiologic data has demonstrated a strong association between the amount of blood in the ventricles and severity of outcomes including mortality, coma, and functional impairment.4 This finding provides substantial support for the therapeutic idea of intraventricular hematoma removal, which has been validated in animal studies. The removal of blood clot from ventricles prevents hydrocephalus and inhibits inflammation mediated progressive tissue damage.5,6 External ventricular drainage (EVD), also known as ventriculostomy, has then been developed to remove the blood or obstructed cerebrospinal fluid (CSF) from the ventricles of the brain, which thus relieves the elevated intracranial pressure (ICP) and hydrocephalus.7 Efforts have been made to improve the drilling and drainage techniques. For example, the method of percutaneous needle trephination has been introduced and performed in case of emergency as a simple, low-risk, effective way to reduce ICP.8,9 Similarly, Zhang et al first introduced a medical device named rapid pore drilling apparatus in 1975, and shortly after reported the first success using the rapid pore drilling technique to perform EVD via the frontal horn of the lateral ventricle, which saved the life of a patient with IVH and severe tonsillar hernia.10,11 It was a fast procedure, completed within 10 minutes, and could be performed at the bedside under sterile condition. Since then, this technique has been adopted in many hospitals in Shandong Province, China. In this study, we collected and analyzed clinical data on 3773 patients who were admitted for IVH at 14 hospitals from 1977 to 2013 and received rapid pore cranial drilling with EVD. The clinical experiences, including operating procedures, duration, technical performances, and the therapeutic effect of rapid pore drilling with EVD were recorded. To our best knowledge, the present study was the biggest one that involved the largest cohort so far and summarized the clinical practice of the rapid pore cranial drilling technique over 30 years. The results indicate that the rapid pore cranial drilling technique is minimally invasive, fast, safe, and effective for treating patients with severe IVH. 相似文献
