Benign schwannoma of posterior mediastinum accompanied by bloody pleural effusion misdiagnosed as solitary fibrous tumor: A case report

Background: Schwannoma is a peripheral nerve sheath tumor originating from schwann cells. It is the most common neurogenic tumor of the posterior mediastinum. Pleural effusion is a rare presentation of benign schwannoma and it is mainly related to malignant tumors. Histologically, schwannoma as well as solitary fibrous tumor should be considered as a differential diagnosis of spindle cell lesions. Case presentation: Here, we report a case of an asymptomatic 61-year-old female misdiagnosed as solitary fibrous tumor of posterior mediastinum which was revealed to have blood stained pleural effusion during the video-assisted thoracic surgery. Eventually pathological study and immunohistochemistry profile of the tumor was reported as benign schwannoma. Conclusion: This report indicates that benign schwannoma can be accompanied by bloody pleural effusion and it also emphasizes the role of immunohistochemistry in the diagnosis of biopsy specimen of spindle cell lesions. &#160

Benign schwannoma of posterior mediastinum accompanied by bloody pleural effusion misdiagnosed as solitary fibrous tumor: A case report

Background: Schwannoma is a peripheral nerve sheath tumor originating from schwann cells. It is the most common neurogenic tumor of the posterior mediastinum. Pleural effusion is a rare presentation of benign schwannoma and it is mainly related to malignant tumors. Histologically, schwannoma as well as solitary fibrous tumor should be considered as a differential diagnosis of spindle cell lesions. Case presentation: Here, we report a case of an asymptomatic 61-year-old female misdiagnosed as solitary fibrous tumor of posterior mediastinum which was revealed to have blood stained pleural effusion during the video-assisted thoracic surgery. Eventually pathological study and immunohistochemistry profile of the tumor was reported as benign schwannoma. Conclusion: This report indicates that benign schwannoma can be accompanied by bloody pleural effusion and it also emphasizes the role of immunohistochemistry in the diagnosis of biopsy specimen of spindle cell lesions. &#160

Transient elastohydrodynamic lubrication analysis of a novel metal-on-metal hip prosthesis with a non-spherical femoral bearing surface

Effective lubrication performance of metal-on-metal hip implants only requires optimum conformity within the main loaded area, while it is advantageous to increase the clearance in the equatorial region. Such a varying clearance can be achieved by using non-spherical bearing surfaces for either acetabular or femoral components. An elastohydrodynamic lubrication model of a novel metal-on-metal hip prosthesis using a non-spherical femoral bearing surface against a spherical cup was solved under loading and motion conditions specified by ISO standard. A full numerical methodology of considering the geometric variation in the rotating non-spherical head in elastohydrodynamic lubrication solution was presented, which is applicable to all non-spherical head designs. The lubrication performance of a hip prosthesis using a specific non-spherical femoral head, Alpharabola, was analysed and compared with those of spherical bearing surfaces and a non-spherical Alpharabola cup investigated in previous studies. The sensitivity of the lubrication performance to the anteversion angle of the Alpharabola head was also investigated. Results showed that the non-spherical head introduced a large squeeze-film action and also led to a large variation in clearance within the loaded area. With the same equatorial clearance, the lubrication performance of the metal-on-metal hip prosthesis using an Alpharabola head was better than that of the conventional spherical bearings but worse than that of the metal-on-metal hip prosthesis using an Alpharabola cup. The reduction in the lubrication performance caused by the initial anteversion angle of the non-spherical head was small, compared with the improvement resulted from the non-spherical geometry

Ultrahigh Molecular Weight Polyethylene/Graphene Oxide Nanocomposites: Wear characterization and Biological Response to wear particles

In the field of total joint replacements, polymer nanocomposites are being investigated as alternatives to ultra high molecular weight polyethylene (UHMWPE) for acetabular cup bearings. The objective of the present study was to investigate the wear performance and biocompatibility of UHMWPE/graphene oxide (GO) nanocomposites. This study revealed that low concentrations of GO nanoparticles (0.5 wt%) do not significantly alter the wear performance of UHMWPE. In contrast, the addition of higher concentrations (2 wt%) led to a significant reduction in wear. In terms of biocompatibility, UHMWPE/GO wear particles did not show any adverse effects on L929 fibroblast and PBMNC viability at any of the concentrations tested over time. Moreover, the addition of GO to a UHMWPE matrix did not significantly affect the inflammatory response to wear particles. Further work is required to optimise the manufacturing processes to improve the mechanical properties of the nanocomposites and additional biocompatibility testing should be performed to understand the potential clinical application of these materials

Histological Survey of the Effect of Granulocyte-colony-stimulating Factor(G-CSF) on Bacterial Translocation and Wound Healing in Burned Mice

Background: Burn wound is an important cause of morbidity and mortality worldwide. Improving the host's immune system and removing the infection can be effective in healing wounds caused by burns. Granulocyte-colony-stimulating factor (G-CSF) stimulates both the bone marrow to produce granulocytes and the function of neutrophil precursors. The aim of this study was to examine the effect of G-CSF on removing infection and healing wound. Materials and Methods: A burn model was used to induce burns in 18 adult Balb/c mice, and their wounds were infected by Acinetobacter baumannii strains. Burned mice were divided into two groups (control and G-CSF) and treated daily by subcutaneous injections of normal saline (0.1 mL) and G-CSF (10 μg/kg). The wound healing process was evaluated by the morphological and histological assessments. Results: In morphological assay, the mean size of the wounds in the 3rd and 7th days of the treatment was significantly lower in the G-CSF treated group compared to the control group. Some of the histological parameters were evaluated, including the level of inflammation, re-epithelialization, angiogenesis, collagen deposition, the amount of granulation tissue, and fibroblast maturation. The results showed that inflammation was reduced in the G-CSF-treated group, and re-epithelialization and collagen deposition were increased insignificantly compared to the normal saline-treated group. Furthermore, bacterial translocation was reduced significantly in the G-CSF-treated group. Conclusion: G-CSF enhances wound closure and helps in wound healing by improving the immune system. It has also an anti-inflammatory role and reduces bacterial translocation

Influence of head size on the development of metallic wear and on the characteristics of carbon layers in metal-on-metal hip joints

Background and purpose Particles originating from the articulating surfaces of hip endoprostheses often induce an inflammatory response, which can be related to implant failure. We therefore analyzed the metal content in capsular tissue from 44 McKee-Farrar metal-on-metal hip prostheses (with 3 different head sizes) and we also analyzed the morphological structure of layers located on articulating surfaces

Wear of ceramic-on-carbon fiber-reinforced poly-ether ether ketone hip replacements

Total hip replacement has been a successful surgi-cal intervention for over 50 years, with the majority of bear-ings using a polyethylene cup. Long-term failure due toosteolysis and loosening has been widely documented andalternative bearings have been sought. A novel carbon fiber-reinforced poly-ether ether ketone (CFR-PEEK) cup was inves-tigated through experimental friction and wear studies. Fric-tion studies demonstrated the bearings operated in aboundary lubrication condition, with friction factors higherthan those for other hip replacement bearings. The wearstudy was conducted with 36 mm diameter bearings testedagainst Biolox Delta heads for a period of 10 million cycles.The mean volumetric wear rate was 0.3 mm3/Mc, indicatingthe ceramic-on-CFR-PEEK bearing to be a very low wearingoption for total hip replacement