BACKGROUND & AIMS: :The advance of mitral valve repair techniques through tissue engineering is impeded by the lack of information regarding the cellular and extracellular components of the mitral valve. The present study aims to expand our understanding of the mitral valve structure by analysing the synthesis of extracellular matrix (ECM) proteins and the expression of nitric oxide synthase (NOS). Valvular endothelial cells (VECs) and valvular interstitial cells (VICs) were isolated from porcine mitral valves. Immunochemical staining of ECM components, including type I, II, III, IV and V collagen, laminin, fibronectin, elastin and chondroitin sulphate (CS), was performed on both mitral valve tissue and cell cultures. Reverse transcription polymerase chain reaction and immunochemistry were used to analyse NOS expression in native valve and in culture. Both VECs and VICs synthesised the basement membrane components, laminin and type IV collagen both in vivo and in vitro, amongst other fibrous ECM proteins. Synthesis of type I collagen and CS was absent in VEC cultures. Each cell type had a characteristic profile of NOS expression. VECs synthesised endothelial NOS both in vivo and in vitro, with a minority of VICs expressing neuronal NOS in vitro. The present study reports newly recognised aspects of the mitral valve structure and the in vitro behaviour of mitral valve cell populations based on ECM synthesis and NOS expression. The presented profiles can be used as base tools for the generation of data necessary for the selection of ideal cell sources and for the design of appropriate scaffolds for the development of effective tissue-engineered mitral valves.

背景与目标： : 缺乏有关二尖瓣细胞和细胞外成分的信息，阻碍了通过组织工程进行二尖瓣修复技术的发展。本研究旨在通过分析细胞外基质 (ECM) 蛋白的合成和一氧化氮合酶 (NOS) 的表达来扩大我们对二尖瓣结构的理解。从猪二尖瓣分离瓣膜内皮细胞 (VECs) 和瓣膜间质细胞 (VICs)。对二尖瓣组织和细胞培养物进行了ECM成分的免疫化学染色，包括I，II，III，IV和V型胶原蛋白，层粘连蛋白，纤连蛋白，弹性蛋白和硫酸软骨素 (CS)。逆转录聚合酶链反应和免疫化学用于分析天然瓣膜和培养物中NOS的表达。VECs和VICs均在体内和体外合成了基底膜成分，层粘连蛋白和IV型胶原蛋白以及其他纤维ECM蛋白。在VEC培养物中没有I型胶原蛋白和CS的合成。每种细胞类型都有NOS表达的特征。VECs在体内和体外合成了内皮NOS，少数VICs在体外表达神经元NOS。本研究报告了基于ECM合成和NOS表达的二尖瓣结构和二尖瓣细胞群体的体外行为的新认识。所呈现的配置文件可用作基础工具，用于生成选择理想细胞源所需的数据以及设计用于开发有效组织工程二尖瓣的适当支架。

BACKGROUND & AIMS: OBJECTIVE:Although there is evidence for a beneficial effect of increased quadriceps strength on knee symptoms, the effect on knee structure is unclear. We undertook this study to examine the relationship between change in vastus medialis cross-sectional area (CSA) and knee pain, tibial cartilage volume, and risk of knee replacement in subjects with symptomatic knee osteoarthritis (OA). METHODS:One hundred seventeen subjects with symptomatic knee OA underwent magnetic resonance imaging of the knee at baseline and at 2 and 4.5 years. Vastus medialis CSA was measured at baseline and at 2 years. Tibial cartilage volume was measured at baseline and at 2 and 4.5 years. Knee pain was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index at baseline and at 2 years. The frequency of knee joint replacement over 4 years was determined. Regression coefficients (B) and odds ratios were determined along with 95% confidence intervals (95% CIs). RESULTS:After adjusting for confounders, baseline vastus medialis CSA was inversely associated with current knee pain (r = -0.16, P = 0.04) and with medial tibial cartilage volume loss from baseline to 2 years (B coefficient -10.9 [95% CI -19.5, -2.3]), but not with baseline tibial cartilage volume. In addition, an increase in vastus medialis CSA from baseline to 2 years was associated with reduced knee pain over the same time period (r = 0.24, P = 0.007), reduced medial tibial cartilage loss from 2 to 4.5 years (B coefficient -16.8 [95% CI -28.9, -4.6]), and reduced risk of knee replacement over 4 years (odds ratio 0.61 [95% CI 0.40, 0.94]). CONCLUSION:In a population of patients with symptomatic knee OA, increased vastus medialis size was associated with reduced knee pain and beneficial structural changes at the knee, suggesting that management of knee pain and optimizing vastus medialis size are important in reducing OA progression and subsequent knee replacement.

背景与目标：

BACKGROUND & AIMS: BACKGROUND CONTEXT:Although autogenous bone is still considered to be the gold standard graft material for promoting spinal fusion, other bone graft substitutes have been developed in an attempt to improve arthrodesis rates and avoid the complications associated with the procurement of autograft. The bone morphogenetic proteins (BMPs) represent a family of osteoinductive growth factors that are known to stimulate the osteoblastic differentiation of stem cells. Osteogenic protein-1 (OP-1) Putty is a commercially available BMP preparation that is already approved for use in humans. Previous clinical studies involving patients with degenerative spondylolisthesis have reported that the efficacy and safety of OP-1 Putty is comparable to that of autograft at both 1- and 2-year follow-up. PURPOSE:The purpose of this study was to evaluate the intermediate-term efficacy and safety of OP-1 Putty as an alternative to autogenous bone by comparing the 4-year radiographic, clinical, and safety data of these same patients who underwent decompression and uninstrumented fusion with either OP-1 Putty or iliac crest autograft. STUDY DESIGN/SETTING:A prospective, randomized, controlled, multicenter clinical pilot study. PATIENT SAMPLE:Thirty-six patients undergoing decompressive laminectomy and single-level uninstrumented fusion for degenerative spondylolisthesis and symptomatic spinal stenosis were randomized in a 2:1 fashion to receive either OP-1 Putty (24 patients) or autogenous iliac crest bone graft (12 patients). OUTCOME MEASURES:Patient-reported outcome measures consisting of Oswestry Disability Index and Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) scores were used to evaluate clinical efficacy. Perioperative data including operative time, estimated blood loss, and duration of hospital stay were also recorded for each surgery. Postoperatively, a neurological examination and an assessment of donor-site pain (if applicable) were performed at every follow-up visit. Radiographic fusion success was defined as the presence of continuous bridging bone formation between the transverse processes at the level of the spondylolisthesis with minimal motion evident on dynamic lateral x-ray films. The primary efficacy endpoint was the overall success rate, a composite measure derived from both radiographic and clinical parameters. The safety of OP-1 Putty was confirmed by comparing the nature and frequency of all adverse events and complications that were prospectively observed in either of the groups. METHODS:Thirty-six patients with degenerative spondylolisthesis and symptoms of neurogenic claudication underwent decompressive laminectomy and single-level uninstrumented fusion with either OP-1 Putty or autograft. All patients were evaluated at 6 weeks and 3, 6, 9, 12, and 24 months, after which time they were instructed to return on a yearly basis. Multiple neuroradiologists blinded to the assigned treatment reviewed static and dynamic X-ray films with digital calipers to assess fusion status according to the presence of continuous bridging bone across the transverse processes as well as the amount of residual motion evident at the level of interest. Oswestry Disability Index surveys and SF-36 questionnaires were used to assess clinical outcomes. RESULTS:At the 48-month time point, complete radiographic and clinical data were available for 22 of 36 patients (16 OP-1 Putty and 6 autograft) and 25 of 36 patients (18 OP-1 Putty and 7 autograft), respectively. Radiographic evidence of a solid arthrodesis was present in 11 of 16 OP-1 Putty patients (68.8%) and 3 of 6 autograft patients (50%). Clinically successful outcomes defined as at least a 20% improvement in preoperative Oswestry scores were experienced by 14 of 19 OP-1 Putty patients (73.7%) and 4 of 7 autograft patients (57.1%); these clinical findings were corroborated by similar increases in SF-36 scores. The respective overall success rates of the OP-1 Putty and autograft group were 62.5% and 33.3%. In this study, there were no incidents of local or systemic toxicity, ectopic bone production, or other adverse events directly related to the use of OP-1 Putty. CONCLUSION:Despite the challenges associated with obtaining a solid uninstrumented fusion in patients with degenerative spondylolisthesis, the rates of radiographic fusion, clinical improvement, and overall success associated with the use of OP-1 Putty were at least comparable to that of the autograft controls for at least 48 months after surgery. These results appear to validate the short-term results previously reported for OP-1 Putty and suggest that this material may potentially represent a viable bone graft substitute for certain fusion applications.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:The purpose of our study was to evaluate planimetry of the aortic valve area with 64-slice CT in comparison with transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) in patients with aortic stenosis. MATERIALS AND METHODS:Thirty-six patients with aortic valve disease referred for coronary 64-slice CT angiography were examined. Planimetry of the aortic valve area with 64-slice CT was compared with TTE using the Doppler continuity equation for calculation of the aortic valve area and with planimetric measurement of the aortic valve area using TEE. RESULTS:Planimetry of the aortic valve area with CT (1.11 +/- 0.42 cm2) showed a good correlation with TTE (1.05 +/- 0.42 cm2) (r = 0.88, p < 0.001) in 32 patients and a good correlation with TEE (1.41 +/- 1.61 cm2) (r = 0.99, p < 0.0001) in 10 patients. The mean and maximum transvalvular pressure gradients were correlated with the aortic valve area as measured with CT (r = -0.68, p = 0.0001; and r = -0.67, p = 0.0001, respectively). Beta-blockers were not given (mean heart rate, 62.5 +/- 10.7 beats per minute). CONCLUSION:MDCT allows accurate planimetry of the aortic valve area in patients with aortic stenosis. In patients referred for 64-slice CT coronary angiography, concomitant aortic stenosis can be identified and evaluated.

背景与目标：

BACKGROUND & AIMS: :Extracellular magnesium ions [Mg2+]o are known to regulate functions of endothelial cells, but whether [Mg2+]o can alter intracellular free ionized magnesium [Mg2+]i in these cells remains unknown. The present studies, using digital imaging microscopy and the Mg2+ fluorescent probe, mag-fura-2, determined effects of elevation of [Mg2+]o on [Mg2+]i in cultured human aortic endothelial cells. With normal Mg2+(1.2 mM)-containing incubation media, [Mg2+]i was 0.51+/-0.04 mM with a heterogeneous distribution. The ratio of [Mg2+]i/[Mg2+]o was 0.52+/-0.07. Elevation of [Mg2+]o up to 4.8 mM increased [Mg2+]i to 0.80+/-0.07 mM in 2-10 min and lowered the ratio of [Mg2+]i/[Mg2+]o to 0.16+/-0.02. Irrespective of the observed increments of [Mg2+]i, a subcellular heterogeneous distribution of [Mg2+]i was always evident in all cells tested. Our results suggest that [Mg2+]o can regulate [Mg2+]i more rapidly than heretofore believed, supporting the hypothesis that extracellular Mg2+ can exert regulatory effects on endothelial cell functions and probably act as extracellular regulatory cations

背景与目标： : 已知细胞外镁离子 [Mg2] o调节内皮细胞的功能，但是 [Mg2] o是否可以改变这些细胞中的细胞内游离电离镁 [Mg2] i仍然未知。本研究使用数字成像显微镜和Mg2荧光探针mag-fura-2确定了 [Mg2] o升高对培养的人主动脉内皮细胞 [Mg2] i的影响。对于含正常Mg2 +(1.2 mM) 的孵育培养基，[Mg2 +]i为0.51 +/-0.04 mM，具有异质分布。[Mg2 +]i/[Mg2 +]o的比率为0.52 +/-0.07。[Mg2 +]o升高至4.8 mM在2-10分钟内使 [Mg2 +]i增加至0.80 +/-0.07 mM，并降低 [Mg2 +]i/[Mg2 +]o与0.16 +/-0.02的比率。不管观察到的 [Mg2] i的增量如何，在所有测试的细胞中，[Mg2] i的亚细胞异质分布总是很明显。我们的结果表明，[Mg2] o可以比以前更快地调节 [Mg2] i，支持以下假设: 细胞外Mg2可以对内皮细胞功能发挥调节作用，并可能充当细胞外调节阳离子

BACKGROUND & AIMS: OBJECTIVE:To define the anatomic characteristics of the congenitally malformed and severely stenotic aortic valve using trans-thoracic real time three-dimensional echocardiography, and to compare and contrast this with the valvar morphology as seen at surgery. DESIGN:Prospective cross-sectional observational study. SETTING:Tertiary centre for paediatric cardiology. METHODS:All patients requiring aortic valvotomy between December 2003 and July 2004 were evaluated prior to surgery with three-dimensional echocardiography. Full volume loop images were acquired using the Phillips Sonos 7500 system. A single observer analysed the images using "Q lab 4.1" software. The details were then compared with operative findings. RESULTS:We identified 8 consecutive patients, with a median age of 16 weeks, ranging from 1 day to 11 years, with median weight of 7.22 kilograms, ranging from 2.78 to 22 kilograms. The measured diameter of the valvar orifice, and the number of leaflets identified, corresponded closely with surgical assessment. The sites of fusion of the leaflets were correctly identified by the echocardiographic imaging in all cases. Fusion between the right and non-coronary leaflets was identified in half the patients. Dysplasia was observed in 3 patients, with 1 patient having nodules and 2 shown to have excrescences. At surgery, nodules were excised, and excrescences were trimmed. The dysplastic changes correlated well with operative findings, though statistically not significant. CONCLUSION:We recommend trans-thoracic real time three-dimensional echocardiography for the assessment of the congenitally malformed aortic valve, particularly to identify sites of fusion between leaflets and to measure the orificial diameter. The definition of nodularity, and the prognosis of nodules based on the mode of intervention, will need a comparative study of patients submitted to balloon dilation as well as those undergoing surgical valvotomy.

背景与目标：

BACKGROUND & AIMS: :A prospective evaluation of 333 consecutive patients undergoing isolated mitral valve replacement between 1982 and 1985 was performed to identify the predictors of survival and valve failure. Follow-up between 2 and 6 years postoperatively (mean, 32 +/- 17 months) was 98% complete. Four prostheses were inserted to permit a prospective evaluation of alternative valves: Björk-Shiley mechanical (n = 118), Ionescu-Shiley pericardial (n = 146), Carpentier-Edwards porcine (n = 38), and Hancock pericardial (n = 31). Hospital mortality was 6%, and actuarial survival at 5 years was 74% +/- 5%. Multivariate Cox regression analysis identified advancing age (less than 40 years, 88% +/- 7%; greater than 70 years, 50% +/- 14%) and poor left ventricular function (ejection fraction less than 0.20, 62% +/- 17%; ejection fraction greater than 0.60, 80% +/- 7%) as independent predictors of postoperative survival. Freedom from structural valve dysfunction, prosthetic valve endocarditis, reoperation, and valve-related mortality and morbidity were 86% +/- 4%, 91% +/- 4%, 81% +/- 4%, and 72% +/- 5%, respectively, at 5 years. The actuarial incidence of valve failure was inordinately high with the Hancock pericardial valve (p less than 0.05). Freedom from thromboembolic events (78% +/- 8% at 5 years) was significantly lower in patients with poor ventricular function (ejection fraction (less than 0.20, 54% +/- 20%; ejection fraction greater than 0.60, 73% +/- 11%; p less than 0.05). Survival after mitral valve replacement was determined by age and left ventricular function. Premature failure of the Hancock pericardial valve resulted in an unacceptable rate of valve-related complications.

背景与目标： : 对333例接受单独二尖瓣置换1982年和1985的连续患者进行了前瞻性评估，以确定生存和瓣膜衰竭的预测因素。术后2至6年 (平均32/- 17个月) 的随访98% 完成。插入四个假体以对替代瓣膜进行前瞻性评估: bj ö rk-Shiley机械 (n = 118)，Ionescu-Shiley心包 (n = 146)，Carpentier-Edwards猪 (n = 38) 和Hancock心包 (n = 31)。医院死亡率为6%，5年时的精算生存率为74% +/- 5%。多因素Cox回归分析发现年龄 (小于40岁，88% +/- 7%; 大于70岁，50% +/- 14%) 和左心室功能差 (射血分数小于0.20，62% +/- 17%; 射血分数大于0.60，80% +/- 7%) 作为术后生存率的独立预测因子。在5年时，免于结构瓣膜功能障碍，人工瓣膜心内膜炎，再次手术以及瓣膜相关的死亡率和发病率分别为86%/- 4%，91%/- 4%，81%/- 4% 和72%/- 5%。汉考克心包瓣膜的精算发生率过高 (p小于0.05)。无血栓栓塞事件 (5年时78% +/- 8%) 在心室功能差的患者中显著降低 (射血分数小于0.20，54% +/- 20%; 射血分数大于0.60，73% +/- 11%; p小于0.05)。二尖瓣置换后的存活率取决于年龄和左心室功能。汉考克心包瓣膜过早衰竭导致瓣膜相关并发症的发生率不可接受。

BACKGROUND & AIMS: BACKGROUND:Various techniques have been proposed for cerebral protection during the surgical treatment of complex aortic disease. The authors propose a revisited strategy of normothermic replacement of the aortic arch to avoid limitations and complications of profound hypothermic circulatory arrest. MATERIALS AND METHODS:From April 2000 to May 2006, 19 patients with an aneurysm of the aortic arch and 10 patients with an acute (7) or a chronic (3) aortic dissection underwent a totally normothermic, complete replacement of the aortic arch using three pumps: One pump ensured antegrade cerebral perfusion, at a flow rate adapted to obtain a pressure of 70 mmHg in the right radial artery, and required a selective cannulation of the supra-aortic vessels. A second pump ensured body perfusion at a flow rate adapted to obtain a pressure of 55 mmHg in the left femoral artery and was situated between the right femoral artery and the right atrium. A special balloon aortic occlusion catheter was placed in the descending thoracic aorta. A third pump ensured intermittent normothermic myocardial perfusion via the coronary venous sinus. The arch reconstruction was performed with no time limit. RESULTS:There were two operative, in-hospital (6.8%) mortalities. All others patients were rapidly extubated, except one, with no neurological sequelae, and postoperative course was uneventful, without coagulopathy or hepato-renal impairment. CONCLUSIONS:In the light of these results, a normothermic procedure is possible for arch surgery and may ensure a more physiological autoregulation of cerebral blood flow while maintaining body perfusion without high vascular resistances.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:The degree of involvement of left ventricular inflow tract obstruction is the predominant factor determining outcome in Shone's anomaly. In this series of patients with Shone's anomaly, we evaluated the impact of mitral valve (MV) repair strategies performed to correct the components of this anomaly on growth of the valve and long-term functional outcome in children. METHODS:In the last 25 years, 45 children, mean age 5.16 ± 5.0 years (median, 3.9; range, 2 months-16.8 years), underwent surgical correction of Shone's anomaly. Coarctation of the aorta was found in 40%, subaortic stenosis due to fibromuscular hypertrophy was found in 55%, and subvalvar membrane was found in 66% of these patients. Left ventricular inflow tract obstruction was brought about by fused commissures with dysplastic and shortened chordae in 53.3%, valve hypoplasia in 11.1%, supravalvar mitral ring in 100%, and parachute valve in 17.8 of patients%. RESULTS:Various repair strategies were performed according to the presenting morphologic characteristics in patients with either previously corrected or concomitant correction of the left-sided obstructive lesions. Mean duration of follow-up was 17.5 ± 1.5 years. Freedom from reoperation was 52.8% ± 11.8%, wherein 23 patients underwent repeated MV repair and 1 patient underwent MV replacement after failed attempts at repair. The cumulative survival rate was 70.3% ± 8.9% at 15 years. Severity and type of mitral abnormalities, left ventricular outflow tract lesions, and pulmonary hypertension are risk factors for reoperation and mortality (p < 0.05). CONCLUSIONS:Repair allowed growth of the MV. Long-term outcome of MV repair in Shone's anomaly is related to the degree that the obstructive lesions can be relieved.

背景与目标：

BACKGROUND & AIMS: :The objective indicators which reflect the past results of end-stage knee osteoarthritis (OA) patients who have already received total knee arthroplasty (TKA) could be helpful for physicians to discuss with patients who are considering TKA. The aim of this prospective cohort study was to examine whether we could predict the knee OA patients who would receive TKA in advance based on baseline data, and to set cut-off points for receiving TKA. The two-hundred and forty end-stage medial-type knee OA patients were enrolled and followed up for 6 months while performing therapeutic exercises. Radiographic findings, visual analog scale for pain and a patient-oriented outcome measure, the Japanese Knee Osteoarthritis Measure (JKOM), were recorded at baseline. Relative risks (RRs) using the area under the curve (AUC) for a receiver operating characteristic (ROC) curve were calculated to evaluate several scores for receiving TKA. While 119 patients (55.3 %) did not undergo TKA, the remaining 96 patients (44.7 %) underwent TKA during this period. The AUCs of the ROC curve for the JKOM total score [0.71 (95 % CI 0.64-0.79)] were higher than those for radiographic parameters. Among the JKOM subcategories, JKOM category III, which indicates the condition in daily life, showed the highest AUC of 0.72 (0.65-0.80). The JKOM total score (65/100) and JKOM category III score (17/40) showed RRs of 2.20 (1.33-3.63) and 1.95 (1.18-3.22) for receiving TKA, respectively. The presence of disability in daily living was found to be an important factor determining whether the patient should undergo TKA.

背景与目标： : 反映已经接受全膝关节置换术 (TKA) 的晚期膝关节骨关节炎 (OA) 患者过去结果的客观指标可能有助于医生与正在考虑TKA的患者进行讨论。这项前瞻性队列研究的目的是检查我们是否可以根据基线数据预测将提前接受TKA的膝OA患者，并设定接受TKA的临界点。纳入了240例终末期内侧型膝OA患者，并在进行治疗性锻炼的同时进行了6个月的随访。在基线时记录了影像学检查结果，疼痛的视觉模拟量表和面向患者的结果测量结果，即日本膝骨关节炎测量 (JKOM)。使用接收器工作特性 (ROC) 曲线的曲线下面积 (AUC) 计算相对风险 (RRs)，以评估接受TKA的几个分数。虽然119名患者 (55.3% 名) 没有接受TKA，但其余96名患者 (44.7% 名) 在此期间接受了TKA。JKOM总分 [0.71 (95% CI 0.64-0.79)] 的ROC曲线的auc高于放射线照相参数的auc。在JKOM子类别中，表示日常生活状况的JKOM类别III显示0.72的AUC最高 (0.65-0.80)。JKOM总分 (65/100) 和JKOM III类得分 (17/40) 显示接受TKA的RRs分别为2.20 (1.33-3.63) 和1.95 (1.18-3.22)。发现日常生活中存在残疾是决定患者是否应接受TKA的重要因素。

BACKGROUND & AIMS: :To determine the etiology of aortic wall dissection, a histopathological study of the aorta in 20 cases with dissecting aortic aneurysm (DA), 3 cases with Marfan syndrome and 3 cases with annulo-aortic ectasia (AAE) was performed. Controls consisted of 348 cases of normally-aging aorta. In cases with aortic wall dissection, the histopathological changes in the undissected media were also carefully examined. In Marfan syndrome and AAE, there was a marked accumulation of acid mucopolysaccharide (AMPS) and its distribution in the wall was diffuse in patients under 50 years old, resulting in changes in elastic fibers including fragmentation, elastolysis and reticulation. In contrast, DA was histopathologically characterized by zonal fibrosis and abnormally-dilated vessels in the aortic media. These lesions were found in 8 (40%) of the 20 DA cases. The remaining 12 cases also had increased vascularization and fragmentation of elastic fibers. This medial fibrosis and increased vascularization were particularly marked in older patients. Among the 3 diseased entities responsible for aortic wall dissection, DA differed distinctly from Marfan syndrome or AAE as to the amount and site of AMPS accumulation in the media as well as fibrosis and hypervascularity in the outer half of the aortic media. In conclusion, aortic wall dissection in younger patients may be etiologically associated with the increased AMPS accumulation in the aortic media which may always be accompanied by degeneration of elastic fibers in this study, however, in older patients zonal fibrosis and abnormal vessels developing in the media are responsible for the dissection.

背景与目标： : 为了确定主动脉壁夹层的病因，对20例夹层主动脉瘤 (DA)，3例Marfan综合征和3例环状主动脉扩张 (AAE) 的主动脉进行了组织病理学研究。对照组包括348例正常老化的主动脉。在主动脉壁夹层的情况下，还仔细检查了未解剖介质的组织病理学变化。在Marfan综合征和AAE中，在50岁以下的患者中，酸性粘多糖 (AMPS) 明显积累，并且其在壁中的分布是弥漫性的，导致弹性纤维的变化，包括碎片，弹性分解和网状。相反，DA的组织病理学特征是主动脉介质中的带状纤维化和异常扩张的血管。在20例DA病例中，有8例 (40% 例) 发现了这些病变。其余12例也有血管化和弹性纤维碎裂的增加。这种内侧纤维化和血管化增加在老年患者中尤为明显。在负责主动脉壁夹层的3个患病实体中，DA与Marfan综合征或AAE在培养基中AMPS积累的数量和部位以及主动脉培养基外半部的纤维化和血管增生方面明显不同。总之，年轻患者的主动脉壁夹层可能与主动脉介质中AMPS积累增加在病因学上有关，在本研究中，这可能总是伴随着弹性纤维的变性，但是，在老年患者中，带状纤维化和异常血管在主动脉介质中发展是造成夹层的原因。

BACKGROUND & AIMS: BACKGROUND:To improve the anatomy-based alignment of prosthetic components in total knee replacement, surgical navigation systems have recently been developed, based on anatomical reference frame definitions through landmark digitations and functional calibration. In this study, femoral and tibial resection plane alignments, obtained by conventional tecnique, were measured intraoperatively during total knee replacements by a navigation system to quantify potential errors in conventional bone preparation techniques. METHODS:Femoral and tibial resection plane alignments, obtained by conventional femoral intramedullary and tibial extramedullary cutting guides, were measured intraoperatively in 25 primary total knee replacements by a navigation system. This system enabled the surgeon to calculate, before definitive bone sawing, the final position and orientation of all resection planes. RESULTS:The measurements revealed unsatisfactory alignments in nearly all anatomical planes. Except for tibial varus/valgus, final plane orientations were considerably different from those targeted by the surgeon via the navigation system, respectively 7 degrees, 8 degrees and 10 degrees apart in varus-valgus and flexion-extension at the femur, and in flexion-extension at the tibia. CONCLUSION:Modern computer-aided surgery in total knee replacement, once relevant precision has been established in all femur and tibia anatomical planes, can in the future limit the current critical component misalignments.

背景与目标：

BACKGROUND & AIMS: :Intra-luminal thrombus has been suggested to play a role in the progression of abdominal aortic aneurysm (AAA). The aims of this study were twofold. Firstly, to assess the reproducibility of a computer tomography (CT)-based technique for measurement of aortic thrombus volume. Secondly, to examine the determinants of infrarenal aortic thrombus volume in a cohort of patients with aortic dilatation. A consecutive series of 75 patients assessed by CT angiography with maximum aortic diameter > or = 25 mm were recruited. Intra-luminal thrombus volume was measured by a semi-automated workstation protocol based on a previously defined technique to quantitate aortic calcification. Intra- and inter-observer reproducibility were assessed using correlation coefficients, coefficient of variation and Bland-Altman plots. Infrarenal aortic thrombus volume percentage was related to clinical, anatomical and blood characteristics of the patients using univariate and multivariate tests. Infrarenal aortic thrombus volume was related to the severity of aortic dilatation assessed by total aortic volume (r = 0.87, P < 0.0001) or maximum aortic diameter (r = 0.74, P < 0.0001). We therefore examined the clinical determinates of aortic thrombus expressed as a percentage of total aortic volume. Aortic thrombus percentage was negatively correlated with serum high density lipoprotein (HDL, r = -0.31). By ordinal multiple logistic regression analysis serum HDL below median (< or = 1.2 mM: ) was associated with aortic thrombus percentage in the upper quartile adjusting for other risk factors (odds ratio 5.3, 95% CI 1.1-25.0). Infrarenal aortic thrombus volume can be measured reproducibly on CT. Serum HDL, which can be therapeutically raised, may play a role in discouraging aortic thrombus accumulation with implications in terms of delaying progression of AAA.

背景与目标： : 腔内血栓已被认为在腹主动脉瘤 (AAA) 的进展中起作用。这项研究的目的是双重的。首先，评估基于计算机断层扫描 (CT) 的主动脉血栓体积测量技术的可重复性。其次，在一组主动脉扩张患者中检查肾下主动脉血栓体积的决定因素。连续招募了75例通过CT血管造影评估的主动脉最大直径> 或 = 25毫米的患者。腔内血栓体积是通过基于先前定义的定量技术的半自动工作站协议测量的，以定量主动脉钙化。使用相关系数，变异系数和Bland-Altman图评估观察者内和观察者间的可重复性。使用单变量和多变量测试，肾下主动脉血栓体积百分比与患者的临床，解剖和血液特征有关。肾下主动脉血栓体积与主动脉总体积 (r = 0.87，P <0.0001) 或主动脉最大直径 (r = 0.74，P <0.0001) 评估的主动脉扩张严重程度有关。因此，我们检查了以总主动脉体积百分比表示的主动脉血栓的临床决定。主动脉血栓百分比与血清高密度脂蛋白 (HDL，r = -0.31) 呈负相关。通过有序多元逻辑回归分析，血清HDL低于中位数 (<或 = 1.2 mM:) 与调整其他危险因素的上四分位数的主动脉血栓百分比相关 (优势比5.3，95% CI 1.1-25.0)。可以在CT上重复测量肾下主动脉血栓体积。可以在治疗上升高的血清HDL可能在阻止主动脉血栓积聚方面发挥作用，从而延迟AAA的进展。

BACKGROUND & AIMS: BACKGROUND:In addition to detecting colorectal neoplasia, abdominal computed tomography (CT) with colonography technique (CTC) can also detect unsuspected extracolonic cancers and abdominal aortic aneurysms (AAA).The efficacy and cost-effectiveness of this combined abdominal CT screening strategy are unknown. METHODS:A computerized Markov model was constructed to simulate the occurrence of colorectal neoplasia, extracolonic malignant neoplasm, and AAA in a hypothetical cohort of 100,000 subjects from the United States who were 50 years of age. Simulated screening with CTC, using a 6-mm polyp size threshold for reporting, was compared with a competing model of optical colonoscopy (OC), both without and with abdominal ultrasonography for AAA detection (OC-US strategy). RESULTS:In the simulated population, CTC was the dominant screening strategy, gaining an additional 1458 and 462 life-years compared with the OC and OC-US strategies and being less costly, with a savings of $266 and $449 per person, respectively. The additional gains for CTC were largely due to a decrease in AAA-related deaths, whereas the modeled benefit from extracolonic cancer downstaging was a relatively minor factor. At sensitivity analysis, OC-US became more cost-effective only when the CTC sensitivity for large polyps dropped to 61% or when broad variations of costs were simulated, such as an increase in CTC cost from $814 to $1300 or a decrease in OC cost from $1100 to $500. With the OC-US approach, suboptimal compliance had a strong negative influence on efficacy and cost-effectiveness. The estimated mortality from CT-induced cancer was less than estimated colonoscopy-related mortality (8 vs 22 deaths), both of which were minor compared with the positive benefit from screening. CONCLUSION:When detection of extracolonic findings such as AAA and extracolonic cancer are considered in addition to colorectal neoplasia in our model simulation, CT colonography is a dominant screening strategy (ie, more clinically effective and more cost-effective) over both colonoscopy and colonoscopy with 1-time ultrasonography.

背景与目标：

BACKGROUND & AIMS: :As the need for hip and knee replacement continues to increase, technical and material changes have allowed a dramatic evolution in the way that degenerative, inflammatory and traumatic arthritis are managed. Advances include new bearing surfaces which should have greater longevity, minimal incision joint replacement, computer guidance and partial joint resurfacing for younger patients. These advances and their implications are discussed.

背景与目标： : 随着对髋关节和膝关节置换的需求不断增加，技术和材料的变化使退行性，炎症性和创伤性关节炎的管理方式发生了巨大变化。进展包括新的轴承表面，应具有更长的寿命，最小的切口关节置换，计算机指导和年轻患者的部分关节重铺。讨论了这些进展及其影响。