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1.
Expression of collagen, interstitial collagenase, and tissue inhibitor of metalloproteinases-1 in restenosis after carotid endarterectomy. 总被引:3,自引:2,他引:3
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S. T. Nikkari R. L. Geary T. Hatsukami M. Ferguson R. Forough C. E. Alpers A. W. Clowes 《The American journal of pathology》1996,148(3):777-783
Extracellular matrix is the principal component of the fibrous caps of atherosclerotic plaques and intimal hyperplastic lesions of reconstructed arteries. Interstitial collagen form an important part of the matrix, and the balance between collagen synthesis and degradation by interstitial collagenase (matrix metalloproteinase-1, MMP-1) may determine whether plaques rupture or vessels develop stenosis. We examined type I procollagen gene expression in human atherosclerotic and restenotic carotid arteries using in situ messenger RNA (mRNA) hybridization and the expression of MMP-1 and its endogenous inhibitor (tissue inhibitor of metalloproteinases-1, TIMP-1) by immunohistochemistry. Compared with normal arteries, atherosclerotic plaques bed increased expression of immunoreactive MMP-1 and TIMP-1 with modest increase of type 1 procollagen mRNA. Early restenotic lesions (< 1.5 years) contained abundant type I procollagen mRNA but little immunoreactive MMP-1 and TIMP-1. Late restenotic lesions (> 4 years) resembled atheroma and exhibited increased immunoreactive MMP-1 and TIMP-1 as well as abundant type I procollagen mRNA. Compared with atherosclerotic plaques, type I procollagen is increased and MMP-1 is decreased in early restenotic lesions. MMP-1 and TIMP-1 expressions are upregulated in lesions with a clear atheroma. These findings suggest that the balance between proteolysis and matrix synthesis may influence both the stability of atheromatous plaques and the development of restenotic lesions. 相似文献
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NEED—The effect of dimensional variability of sheet thickness (tolerance) and tool misalignment is poorly understood for the clinching process. Finite element analysis (FEA) is valuable but requires a lot of and is difficult to verify in this situation due to the asymmetrical geometry and nonlinear plasticity. OBJECTIVE—The objective of this work was to determine the effect of thickness tolerance, tool misalignment and sheet placement (top vs. bottom) in the clinching process, by use of analogue modelling with plasticine. METHOD—Experiments used a scaled-up punch and die, with plasticine as the analogue. Thickness tolerances were represented by sheet thicknesses of 11 and 7 mm, 12 and 8 mm, 8 and 12 mm and 13 and 9 mm for upper and lower sheets, respectively. Two types of lubricant were tested between sheets: glycerine and silicone oil. Angular variability was also introduced. Measured parameters were interlock (also called undercut) and neck thickness. Analogue results for deformation were compared with microscopy of metal clinching. FINDINGS—The results reveal that the multiscale analogue model is an efficient tool for studying the effect of dimensional deviation on a clinch joint. Thickness tolerance showed a critical relationship with interlock, namely a reduction to about half that of the nominal, for both maximum and least material conditions. Increased angular misalignment also reduced the interlock. Compared with glycerine, silicone oil tests showed reduced interlock, possibly the result of a lower coefficient of friction. ORIGINALITY—This work demonstrates the usefulness of analogue modelling for exploring process variability in clinching. The results also show that significant effects for sheet placement are ductility, lubricant (friction), thickness of samples and tool misalignment. 相似文献
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Yaghobi R Behzad-Behbahani A Sabahi F Roustaee MH Alborzi A Ramzi M Nourani H 《Bone marrow transplantation》2005,35(6):595-599
The aim of the study was to determine the prognostic value of a double primer PCR assay to detect human cytomegalovirus (HCMV) infection or disease in bone marrow transplant (BMT) recipients. A total of 209 blood samples including peripheral blood mononuclear cells (PBMN), polymorphonuclear (PMN) leukocytes and plasma from 26 BMT recipients were tested by PCR assay. To discriminate between latent and active HCMV infection, 177 blood samples were also tested by a quantitative antigenemia assay. HCMV serology status of donors and recipients was determined before transplantation by an enzyme immunosorbent assay method. Using the double primer PCR assay, the number of positive samples increased by an average of 11.6%. Symptomatic active HCMV infection was diagnosed in 14 (53.8%) out of 26 BMT patients. There was a good association between double primer PCR assay of PMN leukocytes and antigenemia assays for detection of active HCMV infection in all patients. Detection of HCMV DNA in PMN leukocytes of BMT patients by double primer PCR assay can be an alternative method for antigenemia assay. However, quantitative PCR methods will be necessary for monitoring antiviral treatment. 相似文献
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Antonella Racano MSc Theresa Pazionis MD Forough Farrokhyar PhD Benjamin Deheshi MD MSc FRCS Michelle Ghert MD FRCS 《Clinical orthopaedics and related research》2013,471(6):2017-2027
Background
Limb salvage surgery (LSS) with endoprosthetic replacement is the most common method of reconstruction following bone tumor resection in the adult population. The risk of a postoperative infection developing is high when compared with conventional arthroplasty and there are no appropriate guidelines for antibiotic prophylaxis.Questions/purposes
We sought to answer the following questions: (1) What is the overall risk of deep infection and the causative organism in lower-extremity long-bone tumor surgery with endoprosthetic reconstruction? (2) What antibiotic regimens are used with endoprosthetic reconstruction? (3) Is there a correlation between infection and either duration of postoperative antibiotics or sample size?Methods
We conducted a systematic review of the literature for clinical studies that reported infection rates in adults with primary bony malignancies of the lower extremity treated with surgery and endoprosthetic reconstruction. The search included articles published in English between 1980 and July 2011.Results
The systematic literature review yielded 48 studies reporting on a total of 4838 patients. The overall pooled weighted infection rate for lower-extremity LSS with endoprosthetic reconstruction was approximately 10% (95% CI, 8%–11%), with the most common causative organism reported to be Gram-positive bacteria in the majority of cases. The pooled weighted infection rate was 13% after short-term postoperative antibiotics and 8% after long-term postoperative antibiotics. There was no correlation between sample size and infection rate.Conclusions
Infection rates of 10% are high when compared with rates for conventional arthroplasty. Our results suggest that long-term antibiotic prophylaxis decreases the risk of deep infection. However, the data should be interpreted with caution owing to the retrospective nature of the studies. 相似文献9.
Kevin Chan Forough Farrokhyar Sarah Burrow Marcin Kowalczuk Mohit Bhandari Olufemi R. Ayeni 《Canadian journal of surgery》2013,56(6):422-426
Background
The use of hip arthroscopy has been steadily rising as technology, experience and surgical education continue to advance. Previous reports of the complication rate associated with hip arthroscopy have varied. The purpose of this study was to report our experience with hip arthroscopy complications at a single Canadian institution (McMaster University).Methods
We performed a retrospective chart review of 2 hip arthroscopists at the same institution to identify patients who had undergone the index surgery and had been followed for a minimum of 6 months postoperatively. We used a standard data entry form to collect information on patient demographic and clinical characteristics, including age, sex, surgical indication and type of complication if any.Results
A total of 211 patients underwent 236 hip arthroscopies. The mean age at time of surgery was 37 ± 13 years and mean follow-up was 394 ± 216.5 days. The overall complication rate associated with hip arthroscopy was 4.2% (95% confidence interval 2.3%–7.6%). We identified 4 major and 6 minor complications.Conclusion
Overall, hip arthroscopy appears to be safe, with minor complications occurring more frequently than major ones. However, surgeons should recognize the possibility of serious complications associated with this procedure. Future research should focus on prospective designs looking for potential prognostic factors associated with hip arthroscopy complications. 相似文献10.
Fahimeh Mohammadi Fakhar Forough Rafii Roohangiz Jamshidi Orak 《Burns : journal of the International Society for Burn Injuries》2013