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121.
Thomas K. Fehring Keith A. Fehring Lucas A. Anderson Jesse E. Otero Bryan D. Springer 《The Journal of arthroplasty》2017,32(5):1625-1629
Background
Mechanical complications have been underemphasized in reports on total knee arthroplasty (TKA) in obese patients. Noticing an increased prevalence of varus collapse of the tibia in obese total knee patients, we sought to determine if variability in proximal tibial cancellous bone strength played a role in failure. We attempted to define a cancellous threshold above which alternative methods of fixation should be used.Methods
One thousand one hundred six revision TKAs from 2004-2014 identified 35 patients with varus collapse of the tibia, defined as a change in component position of >10°. Variables analyzed included weight, alignment, component size, and proximal tibial bone stress. Postoperative alignment was compared with prerevision alignment. To calculate tibial stress the following formula was used: mass (kg) × acceleration of gravity (9.8 m/s2)/tibial surface area (mm2) = pascals or N/M2.Results
Twenty-nine of 35 patients weighed >200 lbs, whereas 17 of 35 patients weighed >250 lbs (range 130-354 lbs). Average body mass index was 40.5 kg/m2 (range 24-61 kg/m2). Twenty-seven of 35 failed tibial components were in the lower half of the manufacturer's tibial size offering. Postsurgical alignment averaged 4.9° valgus (range 2° varus-7° valgus) and collapsed an average of 14.9° (range 10°-22°) before revision. Proximal tibial bone stress averaged 334,324 Pascals (range 188,524-601,416). Twenty-five of 35 patients had proximal tibial bone stress >300,000 Pascals.Conclusion
Despite good initial primary TKA alignment, we report catastrophic varus collapse of tibial components in obese patients with small tibial components. When a cancellous threshold of 300,000 Pascals is exceeded, strong consideration should be given to either optimizing the patient's weight or using a longer tibial stem to dissipate forces on proximal tibia. 相似文献122.
Lei Ye Husnain Kh Haider Shujia Jiang Rusan Tan In-Chin Song Ruowen Ge Peter K Law Eugene KW Sim 《老年心脏病学杂志》2006,3(3):152-160
Introduction Extensive cell death and an associated myocardial dys- function are the common features of chronic heart disease. Given the inadequate ability of the human heart to regenerate, a more recent approach to counter the remodel- ing process is to compensate for the loss of functioning cardiomyocyte number through stem cell transplantation with angiomyogenic potential.1,2 The novel approach of heart cell therapy is to repopulate the scar tissue with myogenic cells that may be functional… 相似文献
123.
Changes in TH1/TH2 immunity after endovascular and conventional infrarenal aortic aneurysm repair: its relevance for clinical practice. 总被引:5,自引:0,他引:5
D Decker W Springer P Decker R Tolba J Remig H Strunk A Hirner A von Ruecker 《European journal of vascular and endovascular surgery》2003,25(3):254-261
OBJECTIVE: to evaluate local surgical trauma induced by endovascular (TPEG) and conventional infrarenal aortic aneurysm repair (AAA-C), the inflammatory response and changes in cell-mediated and antibody-mediated immunity as illustrated by the type-1/type-2 T-helper (TH1/TH2) cell balance were investigated. DESIGN: prospective study. PATIENTS AND METHODS: sixteen patients were included, eight patients underwent AAA-C and eight TPEG. Venous peripheral blood samples were collected 24h preoperatively and 24, 48, 72h, 5 and 7 days postoperatively. Besides the WBC, intracellular TH1/TH2 cytokines (IFN-gamma/IL-4) and the cell surface markers HLA-DR on monocytes and CD23 on B cells were measured by four colour flow cytometry. RESULTS: statistically significant higher values in the AAA-C group were demonstrated for neutrophiles. The TH1/TH2 immunobalance (expressed by forming the ratio of IFN-(gamma/IL-4 producing T cells as well as by the ratio of HLA-DR(pos) monocytes/CD23(pos) B-cells) showed a significant shift towards TH2 immunity in the AAA-C group whereas TPEG led to a significant lesser shift 24-72h after surgery (p < 0.05). CONCLUSIONS: TPEG leads to a minor distortion of the TH1/TH2 immunobalance. This implies that TPEG is a less stressing procedure, that is especially beneficial in patients whose conditions are considered less suitable for AAA-C due to age and serious comorbidity. 相似文献
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126.
Elena M. Cornejo Castro Jens Waak Stephanie S. Weber Fabienne C. Fiesel Philipp Oberhettinger Monika Schütz Ingo B. Autenrieth Wolfdieter Springer Philipp J. Kahle 《Journal of neural transmission (Vienna, Austria : 1996)》2010,117(5):599-604
DJ-1 is a neuroprotective gene mutated in recessive Parkinson’s disease (PD). In addition to direct protective functions in neurons,
DJ-1 regulates neuroinflammatory signaling in primary mouse brain astrocytes. To assess the influence of DJ-1 on innate immunity
signaling in vivo, we have generated djr-1 knockout Caenorhabditis elegans. When grown on pathogenic gram-negative bacteria, djr-1
−/− worms showed stronger phosphorylation of p38 mitogen-activated protein kinase (PMK-1) and hyper-induction of PMK-1 target
genes. Thus, PD-associated DJ-1 contributes to regulation of innate immunity. 相似文献
127.
Michael Müller Stephan Tohtz Marc Dewey Ivonne Springer Carsten Perka 《Clinical orthopaedics and related research》2010,468(12):3192-3200
Background
Minimally invasive techniques in THA are intended to minimize periarticular muscle trauma. The lateral approach has a risk of partial gluteal insufficiency, while the anterolateral approach carries the risk of damaging the tensor fasciae latae through intermuscular nerve and compression injury. 相似文献128.
129.
Travis T. Waldron Timothy A. Springer 《Proceedings of the National Academy of Sciences of the United States of America》2009,106(1):85-90
The selectins are cell adhesion proteins that must resist applied forces to mediate leukocyte tethering and rolling along the endothelium and have 2 conformational states. Selectin–ligand bond dissociation increases only modestly with applied force, and exhibits catch bond behavior in a low-force regime where bond lifetimes counterintuitively increase with increasing force. Both allosteric and sliding–rebinding models have emerged to explain catch bonds. Here, we introduce a large residue into a cleft that opens within the lectin domain to stabilize the more extended, high-affinity selectin conformation. This mutation stabilizes the high-affinity state, but surprisingly makes rolling less stable. The position of the mutation in the lectin domain provides evidence for an allosteric pathway through the lectin domain, connecting changes at the lectin–EGF interface to the distal binding interface. 相似文献
130.