组织工程关节软骨梯度仿生支架的研究进展

由于良好的机械性能和生物相容性,组织工程支架已经成为修复和再生关节软骨缺损的重要方法。随着组织工程技术的不断发展,过去十年已经开发和测试了许多支架的制备和形成方法,但是理想再生支架的制备一直存在争议。关节软骨作为人体关节内的承重组织,其基质结构和细胞组成呈带状,并且从软骨表层至软骨下骨存在着几个平滑的自然梯度,包括细胞...     

The role of reamed intramedullary nailing in the treatment of nonunions and malunions following femoral shaft fractures

Summary This retrospective consecutive clinical series describes our satisfactory experience with reamed intramedullary femoral nailing in the treatment of nonunions, axial or rotational deformities as well as length discrepancies following the primary treatment of femoral shaft fractures. 31 patients (32 fractures) treated at our institution from 1992 to 1997 were reviewed for age, gender, cause of injury, type of femur fracture, primary treatment, indication for secondary nailing, operative procedure, complications, need for additional procedures and time for consolidation. 3 patients were lost for follow-up, leaving 28 patients (29 fractures) for evaluation. The average follow-up was 79 weeks (range 24 to 192). The indications for secondary nailing were: 18 nonunions, 7 rotational or axial deformities, 4 length discrepancies. Consolidation was achieved in 25 patients (26 fractures) at an average time of 38 weeks (range 12 to 104). Nonunion was recorded in 3 patients. They were treated successfully with an additional procedure (one exchange intramedullary nailing and two autologous bone grafts). The reamed intramedullary interlocking nail offers many advantages, especially a good initial and middle term stability which is important in case of a slow process of consolidation. By the treatment of atrophic and long lasting nonunion, simultaneous bone grafting seems to be indicated. We conclude that interlocking reamed femoral nailing is a safe treatment option for nonunions and malunions following primary treatment of femoral shaft fractures, resulting in successful union without additional procedure in 26 of 29 fractures in this series.     

Evidence for a direct role of cyclo-oxygenase 2 in implant wear debris-induced osteolysis.

Aseptic loosening is a major complication of prosthetic joint surgery and is manifested as chronic inflammation, pain, and osteolysis at the bone implant interface. The osteolysis is believed to be driven by a host inflammatory response to wear debris generated from the implant. In our current study, we use a selective inhibitor (celecoxib) of cyclo-oxygenase 2 (COX-2) and mice that lack either COX-1 (COX-1-/-) or COX-2 (COX-2-/-) to show that COX-2, but not COX-1, plays an important role in wear debris-induced osteolysis. Titanium (Ti) wear debris was implanted surgically onto the calvaria of the mice. An intense inflammatory reaction and extensive bone resorption, which closely resembles that observed in patients with aseptic loosening, developed within 10 days of implantation in wild-type and COX-1-/- mice. COX-2 and prostaglandin E2 (PGE2) production increased in the calvaria and inflammatory tissue overlying it after Ti implantation. Celecoxib (25 mg/kg per day) significantly reduced the inflammation, the local PGE2 production, and osteolysis. In comparison with wild-type and COX-1-/- mice, COX-2-/- mice implanted with Ti had a significantly reduced calvarial bone resorption response, independent of the inflammatory response, and significantly fewer osteoclasts were formed from cultures of their bone marrow cells. These results provide direct evidence that COX-2 is an important mediator of wear debris-induced osteolysis and suggests that COX-2 inhibitors are potential therapeutic agents for the prevention of wear debris-induced osteolysis.     

Arthropathy associated with anti-Jo-1 antibody

Anti-Jo-1 antibody is associated with an overlap syndrome usually described as the association of idiopathic inflammatory myopathy, pulmonary fibrosis and polyarthritis. We report three observations illustrating different aspects of arthropathy associated with anti-Jo-1 antibody. Two patients presented with a deforming and erosive arthritis affecting the hands, periarticular calcifications and dislocation of the interphalangeal (IP) joint of the thumb. The third patient, who had a short disease course, presented only with a mild non-erosive polyarthritis of both hands, metacarpophalangeal joint narrowing and periarticular calcifications. All the patients had interstitial pulmonary syndrome. Only two of them had myositis. An arthropathy characterized by erosive arthritis of the fingers, with dislocation of the IP joint of the thumb and periarticular calcifications, seems to be specifically associated with anti-Jo-1 antibody.     

Bladder cancer mortality in the Epirus district population (Greece)

Objective: To describe the pattern of bladder cancer mortality in the Epirus district population (North-Western Greece) and to establish some relationships with cigarette smoking. Patients and methods: Mortality rates of bladder cancer in the Epirus district population were analysed according to the official data from the Department of Statistics of the University Hospital of Ioannina during the last decade (January 1990–January 2000). Age –standardization of death rates was done by the direct method, using the world population as a standard. Fisher's test was used as a significance test for linear regression coefficient in time trend analysis of mortality. Results: The average annual standardized mortality rates from bladder cancer during the study period were 5.23 per 100,000population (96% Confidence Interval – CI 4.02–5.63)in males and 1.63 per 100,000 population (96% Confidence Interval– CI 1.18–1.96) in females. Significantly increasing trends of the rates were observed in males (y = 2.421 + 0.231x; p < 0.01), but not in females (y = 1.263 +0.027x; p > 0.05). The greatest increase in age –specific rates in males was observed in the age group of 70 and more years (y = 25.602 + 3.673x; p < 0.01). In females,all age – specific rates except for the group 60–69 years showed significantly increasing tendency. The increasing tendency of bladder cancer mortality is followed by the rise of per capita cigarette consumption among the Epirus district population. Conclusion:Further studies are needed for the explanation of the irregularities in the age-specific rates. This revised version was published online in September 2006 with corrections to the Cover Date.     

An obligatory role for spinal cholinergic neurons in the antiallodynic effects of clonidine after peripheral nerve injury

BACKGROUND: Indirect evidence supports a role of spinal cholinergic neurons in tonically reducing response to noxious mechanical stimulation and in effecting analgesia from alpha2-adrenergic agonists. This study directly assessed the role of cholinergic neurons in regulating the level of mechanical allodynia and in participating in the antiallodynic effect of the clinically used alpha2-adrenergic agonist, clonidine, in an animal model of neuropathic pain. METHODS: Allodynia was produced in rats by ligation of the left L5 and L6 spinal nerves. Rats received a single intrathecal injection of saline or one of three different doses of the cholinergic neurotoxin, ethylcholine mustard aziridinium ion (AF64-A; 2, 5, and 15 nmol). Seven days later, allodynia was assessed before and after intrathecal injection of 15 microg clonidine. The spinal cord was removed, and spinal cord acetylcholine content, cholinergic neuron number and distribution, and alpha2-adrenergic receptor expression were determined. RESULTS: AF64-A administration reduced both the number of cholinergic cells and the acetylcholine content of the lumbar dorsal spinal cord by 20-50% but did not affect level of mechanical allodynia. AF64-A did, however, completely block the anti-allodynic effect of clonidine. AF64-A did not reduce alpha2-adrenergic ligand binding in dorsal lumbar cord. CONCLUSIONS: These data suggest that spinal cholinergic tone does not affect the level of mechanical allodynia after peripheral nerve injury. There is a quantitative reliance on spinal cholinergic neurons in the allodynia relieving properties of intrathecal clonidine, and this reliance does not depend on alpha2-adrenergic receptors colocalized on spinal cholinergic interneurons.     

Functional classification of patients with idiopathic scoliosis assessed by the Quantec system: a discriminant functional analysis to determine patient curve magnitude

STUDY DESIGN: A stepwise discriminant analysis was used to define a spinal deformity score based on three-dimensional measurements by the Quantec spinal image system (raster stereophotograph). OBJECTIVE: To provide functional classification of spinal deformity in patients with mild idiopathic scoliosis without using radiographs. SUMMARY OF BACKGROUND DATA: Most studies classify the degree of spinal deformity in terms of coronal plane radiograph without analyzing transverse rotation. To the authors' knowledge, no studies investigating classification of spinal deformity in idiopathic scoliosis using Quantec system measurements have been documented. METHODS: In this study, 129 patients with a single curve and 119 patients with a double curve were divided into three groups according to Cobb angle: Group 1 (less than 10 degrees ), Group 2 (10-20 degrees ), and Group 3 (greater than 20 degrees ). RESULTS: The patients were assigned to the group with the highest scores after application of a stepwise discriminant analysis. The accuracy of the classification system by functional scores for the patients with a single curve was 85% for Group 1, 63.5% for Group 2, and 71.7% for Group 3. The accuracy of classification by functional scores for the patients with a double curve was 87.1% for Group 2 and 76.1% for Group 3. CONCLUSION: The back surface image study is a method for providing a quantitative assessment of mild spinal deformity, allowing evaluation of patients by integrated three-dimensional parameters with no reference to radiographs.     

Virtual hepatic resection using three-dimensional reconstruction of helical computed tomography angioportograms

OBJECTIVE: To establish the accuracy of virtual hepatic resection using three-dimensional (3D) models constructed from computed tomography angioportography (CTAP) images in determining the liver volume (LV) resected during resectional liver surgery. SUMMARY BACKGROUND DATA: The ability to measure LV before surgery could be useful in determining the extent and nature of hepatic resection. Accurate assessment of LV and an estimate of liver function may also allow prediction of postoperative liver failure in patients undergoing resection, assist in volume-enhancing embolization procedures, help with the planning of staged hepatic resection for bilobar disease, and aid in selection of living-related liver donors. METHODS: A retrospective study was conducted involving 27 patients scheduled for liver resection. Using mapping technology, 3D models were constructed from helical CTAP images. From these 3D models, tumor volume, total LV, and functional LV were calculated and were compared with body weight. The 3D liver models were subjected to a virtual hepatectomy along established anatomical planes, and the resected LV was calculated. The resected volume predicted by radiologists (unaware of the actual weight) was compared with the specimen weight measured after actual surgical resection. RESULTS: A significant correlation was found between body weight and functional LV but not total LV. The computer prediction of resected LV after virtual hepatectomy of 3D models compared well with resected liver weight. CONCLUSION: Virtual hepatectomy of 3D CTAP reconstructed images provides an accurate prediction of liver mass removed during subsequent hepatic resection. The authors intend to combine this technology with an assessment of liver function to attempt to predict patients at risk for liver failure after hepatic resection.