广东东莞地区中老年非暴力性骨折107例及无骨折求诊者392例超声骨密度测定

目的:应用超声骨密度/骨质量测量仪对东莞地区中老年非暴力性骨折患者进行检测,探讨各参数的变化规律及临床意义,并确立骨折的骨密度阈值。方法:①实验对象:选择2003-09/2006-08在东莞石龙人民医院进行超声骨密度测定的非暴力性骨折东莞地区中老年患者107例,男30例,女77例;同期同龄进行超声骨密度测定的无骨折求诊者392例,作为对照组,男83例,女309例。②实验分组:根据年龄分为3个时期:46～60岁为老年前期、61～75岁为老年期、76岁以上为高龄期,以及相应男女组及骨折与非骨折组。③实验方法:采用法国DMS公司UBIS5000型超声骨密度/骨质量测量仪对中老年非暴力性骨折者、无骨折就诊者进行超声骨密度测量。④实验评估:比较两组男女及不同年龄段超声振幅衰减平均值、超声传播速度、骨硬度指数、T值(代表患者测量值如超声振幅衰减平均值和20岁正常人的测量值之间的差异)、Z值(代表患者测量值如超声振幅衰减平均值和同龄正常人的测量值之间的差异)。结果:两组499例患者全部进入结果分析。①总体比较:男、女性骨折组与非骨折组比较,除超声传播速度差别无统计学意义外(P>0.05),其余指标(超声振幅衰减、骨硬度指数、T值、Z值)非骨折组高于骨折组(P<0.01)。②分年龄组比较:老年前期组与总体一致,老年组、高龄组主要指标无统计学意义。应用方差分析对女性骨折组各年龄组之间进行比较,除骨硬度指数外(P<0.05),其余指标差异无显著性;男性骨折组各年龄组之间比较得出与女性一样结果。③男性与女性骨折组比较:除T值男性组高于女性组外(P<0.01),其余指标(超声振幅衰减、超声传播速度、骨硬度指数、Z值)差异均无统计学意义。结论:①中老年人群骨质下降至一定程度(相应测量参数为骨折阈值)时容易发生脆性骨折。②致脆性骨折的骨质量条件与性别、年龄因素无明显相关性。③东莞地区步入老年期后不论男女骨质疏松现象相当普遍,是否会出现骨折关键在于有否外力作用,对其预防性诊断很有价值。     

具有防坠床功能的智能护理床的研制

目的:设计一种护理床,以预防缺乏自控能力的老年人和智障人员发生坠床危险。方法:利用重心测定原理,计算患者在床上的位置,并辅以红外探测报警,实现自动报警防坠床的主要功能。结果:该护理床在Labview环境下编制监控程序,建立自动监控报警系统;以相应比例的砝码代替患者进行实验测试。结论:测试结果表明:①该装置监控到报警响应时间短,能够及时发现隐患,减少患者意外发生。②护理床采用全自动监控报警,可减轻护理人员的负担。     

Ex vivo cardiovascular magnetic resonance measurements of right and left ventricular mass compared with direct mass measurement in excised hearts after transplantation: a first human SSFP comparison

Background

CMR is considered the ‘gold standard’ for non-invasive LV and RV mass quantitation. This information is solely based on gradient-recalled echo (GRE) sequences while contrast dependent on intrinsic T1/T2 characteristics potentially offers superior image contrast between blood and myocardium. This study aims, for the first time in humans, to validate the SSFP approach using explanted hearts obtained from heart transplant recipients. Our objective is establish the correlation between and to validate steady-state free precession (SSFP) derived LV and RV mass vs. autopsy mass of hearts from cardiac transplants patients.

Methods

Over three-years, 58 explanted cardiomyopathy hearts were obtained immediately upon orthotopic heart transplantation from the OR. They were quickly cleaned, prepared and suspended in a saline-filled container and scanned ex vivo via SSFP-SA slices to define LV/RV mass. Using an automatic thresholding program, segmentation was achieved in combination with manual trimming (ATMT) of extraneous tissue incorporating 3D cardiac modeling performed by independent and blinded readers. The explanted hearts were then dissected with the ventricles surgically separated at the interventricular septum. Weights of the total heart not excluding papillary and trabecular myocardium, LV and RV were measured via high-fidelity scale. Linear regression and Bland-Altman plots were used to analyze the data. The intra-class correlation coefficient was used to assess intra-observer reliability.

Results

Of the total of 58 explanted hearts, 3 (6%) were excluded due to poor image quality leaving 55 patients (94%) for the final analysis. Significant positive correlations were found between total 3D CMR mass (450 ± 111 g) and total pathology mass (445 ± 116 g; r = 0.99, p < 0.001) as well as 3D CMR measured LV mass (301 ± 93 g) and the pathology measured LV mass (313 ± 96 g; r = 0.95, p < 0.001). Strong positive correlations were demonstrated between the 3D CMR measured RV mass (149 ± 46 g) and the pathology measured RV mass (128 ± 40 g; r = 0.76, p < 0.001). The mean bias between 3D-CMR and pathology measures for total mass, LV mass and RV mass were: 3.0 g, -16 g and 19 g, respectively.

Conclusions

SSFP-CMR accurately determines total myocardial, LV and RV mass as compared to pathology weighed explanted hearts despite variable surgical removal of instrumentation (left and right ventricular assist devices, AICD and often apical core removals). Thus, this becomes the first-ever human CMR confirmation for SSFP now validating the distinction of ‘gold standard’.     

ORAI1-mediated calcium influx is required for human cytotoxic lymphocyte degranulation and target cell lysis

Lymphocytes mediate cytotoxicity by polarized release of the contents of cytotoxic granules toward their target cells. Here, we have studied the role of the calcium release-activated calcium channel ORAI1 in human lymphocyte cytotoxicity. Natural killer (NK) cells obtained from an ORAI1-deficient patient displayed defective store-operated Ca(2+) entry (SOCE) and severely defective cytotoxic granule exocytosis leading to impaired target cell lysis. Similar findings were obtained using NK cells from a stromal interaction molecule 1-deficient patient. The defect occurred at a late stage of the signaling process, because activation of leukocyte functional antigen (LFA)-1 and cytotoxic granule polarization were not impaired. Moreover, pharmacological inhibition of SOCE interfered with degranulation and target cell lysis by freshly isolated NK cells and CD8(+) effector T cells from healthy donors. In addition to effects on lymphocyte cytotoxicity, synthesis of the chemokine macrophage inflammatory protein-1β and the cytokines TNF-α and IFN-γ on target cell recognition was impaired in ORAI1-deficient NK cells, as previously described for T cells. By contrast, NK cell cytokine production induced by combinations of IL-12, IL-15, and IL-18 was not impaired by ORAI1 deficiency. Taken together, these results identify a critical role for ORAI1-mediated Ca(2+) influx in granule exocytosis for lymphocyte cytotoxicity as well as for cytokine production induced by target cell recognition.     

LV reverse remodeling imparted by aortic valve replacement for severe aortic stenosis; is it durable? A cardiovascular MRI study <Emphasis Type="Italic">sponsored by the American Heart Association</Emphasis>

Background  

In patients with severe aortic stenosis (AS), long-term data tracking surgically induced effects of afterload reduction on reverse LV remodeling are not available. Echocardiographic data is available short term, but in limited fashion beyond one year. Cardiovascular MRI (CMR) offers the ability to serially track changes in LV metrics with small numbers due to its inherent high spatial resolution and low variability.     

Increased sensitivity of antigen-experienced T cells through the enrichment of oligomeric T cell receptor complexes

Although memory T?cells respond more vigorously to stimulation and they are more sensitive to low doses of antigen than naive T?cells, the molecular basis of this increased sensitivity remains unclear. We have previously shown that the T?cell receptor (TCR) exists as different-sized oligomers on the surface of resting T?cells and that large oligomers are preferentially activated in response to low antigen doses. Through biochemistry and electron microscopy, we now showed that previously stimulated and memory T?cells have more and larger TCR oligomers at the cell surface than their naive counterparts. Reconstitution of cells and mice with a point mutant of the CD3ζ subunit, which impairs TCR oligomer formation, demonstrated that the increased size of TCR oligomers was directly responsible for the increased sensitivity of antigen-experienced T?cells. Thus, we?propose that an "avidity maturation" mechanism underlies T?cell antigenic memory.     

自体外周血干细胞经冠状动脉移植治疗急性心肌梗死：近期疗效随访

目的:观察经皮经腔冠状动脉内移植外周血干细胞治疗急性心肌梗死的可行性与近期临床疗效。方法:①实验对象:选取2003-11/2005-01辽宁省人民医院收治的急性心肌梗死患者70例,男56例,女14例,年龄(60±10)岁,体质量(73±11)kg,急性心肌梗死病程(5±2)d,均对本实验知情同意,实验方案经辽宁省人民医院伦理委员会批准。70例患者随机数字表法分为细胞移植组、常规治疗组,35例/组。两组基线资料基本相似。②实验方法:常规治疗组单纯给予药物治疗 冠状动脉造影术或支架植入术。细胞移植组在常规治疗的基础上应用粒细胞集落刺激因子皮下注射动员自体骨髓干细胞,连续5d,第6天经血细胞分离机分离采集外周血干细胞悬液57mL,经over the wire球囊导管中心腔注入梗死相关动脉,注入CD34细胞数量为(7.25±7.33)×107个。③实验评估:在外周血干细胞动员、采集及经冠状动脉回输过程中观察患者不良反应。于术前及术后6个月检查两组患者左室形态、心功能、室壁节段性运动积分的改变。结果:术后6个月,细胞移植组全部完成随访,常规治疗组23例完成随访。①手术前后超声心动图参数值的变化:与术前比较,术后6个月细胞移植组左室收缩末容积、室壁节段性运动积分指数均明显下降(P<0.05),左室射血分数显著升高(P<0.05)。术后6个月与常规治疗组比较,细胞移植组左室射血分数明显升高,室壁节段性运动积分指数显著降低,差异有显著性意义(P<0.05)。②安全性评估:外周血干细胞动员时不良反应占37.1%,分离和采集过程不良反应占15.3%,经冠状动脉内回输过程不良反应占20.0%。结论:经皮经腔冠状动脉移植自体外周血干细胞治疗急性心肌梗死,可在近期有效地减少心肌梗死缺血面积,减轻左室重构,改善心功能。     

The short length of the extracellular domain of zeta is crucial for T cell antigen receptor function

The T cell antigen receptor (TCR-CD3) consists of the pMHC-binding TCRalphabeta heterodimer and the signalling dimers CD3deltaepsilon, CD3gammaepsilon and zetazeta. The very short length of the extracellular domain (EC) of the zeta chain is preserved through evolution, however a rational explanation for this observation has not been elucidated. Here, we show that TCR-CD3 assembly is clearly defective when the murine zeta EC domain is artificially enlarged. Under these conditions, the TCR-CD3 complex is super-competent in transducing activation signals upon engagement. Furthermore, the TCR-CD3 complexes containing enlarged zeta EC domains underwent ligand-induced conformation changes with higher efficiency than TCR-CD3 complexes with an unmodified zeta EC domain. Together these data suggest that a short zeta EC domain is needed to correctly assemble the TCR-CD3 complex. When this domain is enlarged, the resulting TCR-CD3 complex is distorted leading to a hyperactive phenotype and enhanced T cell activation.     

Mesenchymal hamartoma of the liver: radiologic-pathologic correlation

Mesenchymal hamartoma of the liver (MHL) is an uncommon cystic mass of infancy that is a developmental anomaly rather than a neoplasm. Fourteen cases of MHL were retrospectively reviewed. Grossly, MHL is a solitary mass with cystic spaces of variable size. Patients are seen initially with painless progressive abdominal enlargement. On plain films, MHL appears as a large, noncalcified mass in the right upper quadrant. Scintigraphy is helpful in confirming its hepatic origin. Ultrasonography and computed tomography demonstrate a large multiloculated mass with considerable variation in the size of septa and cystic spaces. Angiographically, MHL is avascular or hypovascular. Recognition of these radiographic findings allows a correct diagnosis to be made in many cases. With resection, the prognosis is excellent.