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991.
Christopher Del Balso Matthew G. Teeter Sok C. Tan Brent A. Lanting James L. Howard 《The Journal of arthroplasty》2018,33(1):268-272
Background
Trunnionosis at the modular head-neck taper interface in metal-on-polyethylene total hip arthroplasty (MoP THA) has been shown to occur, and represents a potential mode of MoP THA failure. The purpose of the present investigation is to elucidate differences in fretting and corrosion at the head-neck taper interface of prostheses retrieved from bipolar hemiarthroplasty (BH) and MoP THA.Methods
A retrieval analysis of BH and MoP THA prostheses featuring a single taper design from a single manufacturer and in vivo for a minimum 2 years was performed. Fifteen femoral heads of 28-mm diameter and corresponding femoral stems retrieved from BH were compared with MoP THA implants matched based on time in vivo and head length (28 mm, ?3 mm to 28 mm, +8 mm). Fretting and corrosion damage scoring was completed under stereomicroscopic visualization.Results
Femoral head bore tapers retrieved from BH exhibited decreased overall fretting (P = .02), when compared to those retrieved from MoP THA. Total corrosion scores for all retrieved implants were positively correlated with implantation time (ρ = 0.54, P < .02).Conclusion
Femoral heads retrieved from BH exhibit decreased fretting damage compared to those retrieved from MoP THA. The added articulation in BH implants may decrease torque produced at the head-neck taper junction, thereby decreasing fretting. Increased fretting damage in implants from MoP THA is not associated with increased corrosion in 28-mm heads of this taper design. The longer a BH or MoP THA prosthesis is implanted, the greater the risk of damage due to corrosion. 相似文献992.
Autologous immature myoblasts are obtained from biopsy of thigh muscle. These cells are cultured to a thera peutic dosage at a central Good Manufacture Practic (cGMP) facility. The cells are suspended in a special solu tion which preserves their shelf lif… 相似文献
993.
Hamady ZZ Malik HZ Finch R Adair R Al-Mukhtar A Prasad KR Toogood GJ Lodge JP 《Annals of surgical oncology》2006,13(11):1493-1499
Background Many colorectal liver metastasis patients are denied surgical resection on the basis of tumour size. The aim of this study was to explore the impact of metastasis size on modern liver resection.Methods Using a prospectively collected database, this was a retrospective analysis of 484 consecutive patients who underwent liver resection for colorectal liver metastases between 1993 and 2003. The cohort was divided into two groups: smaller metastases (<8 cm) and larger metastases (≥ 8 cm). Those with larger metastases were then further stratified into big metastases (8–12 cm) and giant metastases (>12 cm). Demographic, pathological, surgical technique and outcome data were compared between the groups.Results There were 88 (18%) patients with metastases measuring 8 cm or larger. There was an association between higher carcinoembryonic antigen (CEA) and cancer antigen (CA) 19-9 levels and larger metastases. The actuarial 5-year survival for patients with larger metastases was 38% compared with 42% for smaller metastases (not statistically significant). Patients with giant metastases had poorer overall and disease-free survival (both nonsignificant) compared with those with big metastases: 29% and 28% at 5 years, respectively.Conclusion Patients with colorectal liver metastasis greater than 8 cm and up to 12 cm in size should not be treated differently from those with smaller lesions. 相似文献
994.
995.
Vikas Dudeja Leonard H. Armstrong Pankaj Gupta Howard Ansel Sabeen Askari Waddah B. Al-Refaie 《Journal of gastrointestinal surgery》2010,14(3):557-561
Introduction
Gastrointestinal stromal tumors (GISTs) are the most common gastrointestinal mesenchymal tumors. The activating mutation in the KIT (c-kit; CD117) proto-oncogene with subsequent tyrosine kinase activation plays a central role in the pathogenesis of GIST. Tyrosine kinase inhibitors are an integral part of GIST therapy. Initial response to neoadjuvant imatinib can be expected in up to 70% of the patients, thus offering an opportunity to surgically treat those with locally advanced primary or recurrent GIST. This favorable response to imatinib, however, is plagued with development of secondary resistance during the course of therapy. 相似文献996.
Howard Trachtman 《Pediatric nephrology (Berlin, Germany)》1991,5(6):743-750
Control of cell size within defined limits is vital for maintenance of normal organ function. This important feature of cell physiology can be disturbed by changes in membrane transport in epithelial cells. In addition, fluctuations in the osmolality of the extracellular fluid, caused by an abnormal plasma concentration of sodium, glucose, or urea can lead to derangements in cell size. Cell volume regulation is especially important in the brain because the brain is confined within a non-compliant vault and cannot tolerate significant perturbations in cell size. Therefore, brain cells have developed a coordinated array of adaptive mechanisms designed to modulate the cytosolic content of osmotically active solutes in response to alterations in the osmolality of the extracellular fluid. This process is controlled by various hormones including arginine vasopressin, insulin, and estrogen, and is subject to changes during development. The bulk of the change in cell content of osmolytes involves inorganic electrolytes. However, excessive variation in the cytosolic ionic strength has deleterious effects on protein structure and enzyme function. Therefore, brain cells have developed the capacity to accumulate or extrude various organic osmolytes in order to adjust the cytosolic osmolality without adversely affecting cell function. These solutes are termed non-pertubing osmolytes and belong to one of three classes of molecules: amino acids, carbohydrates and polyhydric sugar alcohols, or methylamines. Cerebral cells regulate the cytosolic content of organic osmolytes primarily by altering the transmembrane flux of these solutes. There are features of the cell volume regulatory response that are shared by the brain and kidney cells. However, there are important interorgan differences including the speed of response, the exact identitiy of the organic osmolytes utilized by each organ, and the reliance upon de novo osmolyte synthesis rather than transport in modulating cytosolic content of these solutes. An improved understanding of the cerebral cell volume regulatory response has led to better treatment of clinical disorders of plasma osmolality.Part II of this survey will be published in Pediatr Nephrol (1992) Volume 6, Issue 1 相似文献
997.
Susan C. Pitt Henry A. Pitt Marshall S. Baker Kathleen Christians John G. Touzios James M. Kiely Sharon M. Weber Stuart D. Wilson Thomas J. Howard Mark S. Talamonti Layton F. Rikkers 《Journal of gastrointestinal surgery》2009,13(9):1692-1698
Objective The aim of this study was to compare the outcomes of enucleation versus resection in patients with small pancreatic, ampullary,
and duodenal neuroendocrine tumors (NETs).
Methods Multi-institutional retrospective review identified all patients with pancreatic and peri-pancreatic NETs who underwent surgery
from January 1990 to October 2008. Patients with tumors ≤3 cm and without nodal or metastatic disease were included.
Results Of the 271 patients identified, 122 (45%) met the inclusion criteria and had either an enucleation (n = 37) and/or a resection (n = 87). Enucleated tumors were more likely to be in the pancreatic head (P = 0.003) or functioning (P < 0.0001) and, when applicable, less likely to result in splenectomy (P = 0.0003). The rate of pancreatic fistula formation was higher after enucleation (P < 0.01), but the fistula severity tended to be worse following resection (P = 0.07). The enucleation and resection patients had similar operative times, blood loss, overall morbidity, mortality, hospital
stay, and 5-year survival. However, for pancreatic head tumors, enucleation resulted in decreased blood loss, operative time,
and length of stay compared to pancreaticoduodenectomy (P < 0.05).
Conclusion These data suggest that most outcomes of enucleation and resection for small pancreatic and peri-pancreatic NETs are comparable.
However, enucleation has better outcomes than pancreaticoduodenectomy for head lesions and the advantage of preserving splenic
function for tail lesions.
Presented at the 2009 American Hepatopancreaticobiliary Association, March 14, 2009, Miami, FL
American College of Surgeons Resident Research Scholarship, NIH Grant T32 CA009614 Physician Scientist Training in Cancer
Medicine. 相似文献
998.
A comparison of the microarchitectural bone adaptations of the concave and convex thoracic spinal facets in idiopathic scoliosis 总被引:7,自引:0,他引:7
Shea KG Ford T Bloebaum RD D'Astous J King H 《The Journal of bone and joint surgery. American volume》2004,(5):1000-1006
BACKGROUND: A limited number of studies have assessed the changes in bone microarchitecture in spinal facets with use of light microscopy but not with use of electron microscopy techniques. The purpose of this study was to analyze the facets in patients with scoliosis to determine whether there are differences in the bone microarchitecture of contralateral facets at the same anatomic level. METHODS: In eight patients undergoing posterior spinal arthrodesis for the treatment of idiopathic scoliosis, biopsy specimens of facet pairs at matched anatomic levels were obtained from three locations: (1). the curve apex, (2). one level cephalad to the apex, and (3). one level caudad to the apex. The facets were analyzed for cortical bone porosity and thickness with use of scanning electron microscopy and National Institutes of Health imaging software. The concave and convex facets were compared with use of a paired t test. RESULTS: The mean porosity (and standard deviation) for the concave and convex facets was 16.5% +/- 5.8% and 24.1% +/- 6.2%, respectively. Those on the convex side were significantly more porous than those on the concave side (p 相似文献
999.
1000.
Matthew A. Hamilton Phong Diep Chris Roche Pierre Henri Flurin Thomas W. Wright Joseph D. Zuckerman Howard Routman 《Journal of orthopaedic research》2015,33(4):605-613
This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post‐operatively. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:605–613, 2015. 相似文献