超声二维应变成像评价正常人等容收缩期左心室局部心肌运动特点

目的 应用超声二维应变成像观察正常人等容收缩期局部心肌纵向应变特点。方法 采集27名正常人心尖四腔心、两腔心和心尖左心室长轴切面的二维灰阶动态图像,应用二维应变软件获得等容收缩期应变曲线,计算等容收缩期出现正向应变(ε_+IVC)曲线的心肌节段数及其检出率,分析最大负向应变(ε_－IVC)、ε_+IVC检出率、ε_+IVC峰值在各水平(基底段、中间段和心尖段)、各室壁(后间隔、侧壁、下壁、前壁、后壁、前间隔)心肌间的差异。结果 正常人等容收缩期的应变曲线以绝对值逐渐增大的负向应变曲线最为多见,ε_－IVC的绝对值从基底段至心尖段递增,后壁、后间隔、下壁均小于前壁、侧壁、前间隔,除后间隔和下壁与前间隔差异无统计学意义外,其余差异均有统计学意义(P均＜0.05)。20.89%的节段出现正向应变曲线,其中基底段心肌比心尖段心肌多见,后壁、后间隔、下壁心肌比前壁、前间隔、侧壁心肌多见,除下壁与侧壁和前间隔差异无统计学意义外,其余差异均有统计学意义(P均＜0.05)。结论 等容收缩期左心室心肌是有形变的,应用超声二维应变成像可快速、简便地检测等容收缩期心肌的形变。     

速度向量成像评价胰岛素对糖尿病心肌病大鼠心肌功能的影响

目的 应用VVI定量评价胰岛素治疗后糖尿病心肌病大鼠心肌功能的变化。 方法 30只雄性SD大鼠,随机分为糖尿病组(DM组)、胰岛素治疗组(INS组)和正常对照组(CON组),每组10只。腹腔注射链脲佐菌素建立糖尿病模型后,INS组给予胰岛素皮下注射(6 U/kg体质量),每日一次。于造模成功12周后开胸,取左心室短轴图像进行VVI分析,并取心肌组织行透射电镜观察。 结果 与DM组比较,INS组收缩和舒张期径向峰值速度(Vs、Vd)、径向峰值应变(Sr)、收缩期径向峰值应变率(收缩期SRr)以及切向峰值应变(Sc)、收缩和舒张期切向峰值应变率(收缩期SRc、舒张期SRc)均较高(P＜0.05);舒张期径向峰值应变率(舒张期SRr)与DM组差异无统计学意义(P＞0.05)。与CON组比较,INS组除舒张期SRr、收缩期SRc、舒张期SRc较低(P＜0.05)外,余指标与CON组差异无统计学意义(P＞0.05)。 结论 胰岛素能明显改善糖尿病心肌病大鼠的心肌功能;VVI应变率指标在评估糖尿病心肌病治疗疗效及预后方面起着重要作用。     

超声生物显微镜斑点追踪成像评价正常小鼠左心室内、外膜心肌应变

目的 应用超声生物显微镜(UBM)及斑点追踪(STI)技术探讨不同月龄正常小鼠左心室内膜及外膜心肌应变的特征。 方法 对48只不同月龄的健康成年雄性小鼠行常规超声心动图检查,采集胸骨旁左心室长轴、乳头肌水平左心室短轴二维图像。常规超声心动图测量舒张末期室间隔厚度(IVST)、左心室后壁厚度(LVPWT)、左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室射血分数(LVEF)、左心室内径缩短率(LVFS)。脱机分析两个不同切面左心室内、外膜的纵向应变、圆周应变及径向应变的峰值应变(PK)、达峰时间(TPk)、室壁最大达峰延迟时间(MOWD)等指标。 结果 不同月龄间心率、IVST、LVPWT、LVEDD和LVESD的差异无统计学意义。与3月龄组比较,12月龄组LVEF、LVFS均减小(P＜0.05)。随月龄增加,小鼠左心室内膜下和外膜下心肌纵向、圆周及径向PK均呈逐渐减小的趋势:与3月龄组相比,12月龄组的测值均明显减小(P＜0.05);与6月龄组相比,12月龄组径向应变测值也明显减小(P＜0.05)。外膜下心肌的纵向及圆周应变均显著小于内膜下心肌(P＜0.01)。随月龄增加,左心室内膜下和外膜下心肌纵向、圆周及径向TPk、MOWD均呈逐渐增大趋势。与3、6月龄组相比,12月龄组的部分测值明显增大(P＜0.05)。同月龄正常小鼠内膜下及外膜下心肌纵向、圆周TPk及MOWD接近(P＞0.05)。 结论 UBM及STI技术能够无创、简便地全面评价正常小鼠左心室内、外膜下心肌的应变;所获不同月龄正常小鼠心脏结构及功能的正常测量值范围可为今后其他小鼠心脏模型的研究提供参考依据。     

速度向量成像技术对正常人颈总动脉管壁形变特征的初步研究

目的 应用速度向量成像（VVI） 技术初步研究正常人颈总动脉管壁形变特征.方法 超声采集并动态存储47 例正常人颈总动脉长轴及短轴二维灰阶图像.应用VVI技术观察颈总动脉管壁纵向和周向应变及应变率曲线,以同步记录心电图为时相对照,测量颈总动脉管壁收缩期纵向和周向峰值应变及应变率.结果 正常人颈总动脉后壁近心点、中点及远心点间的收缩期纵向峰值应变及峰值应变率差异无统计学意义（P〉0.05）;正常人颈总动脉短轴管壁各节段间收缩期周向峰值应变及应变率差异无统计学意义（P〉0.05）.结论 正常人颈总动脉管壁收缩期纵向峰值应变及应变率沿颈总动脉后壁长轴分布基本均匀,收缩期周向峰值应变及应变率在颈总动脉管壁短轴方向分布亦基本均匀.     

超声速度向量成像技术评价主动脉瓣置换同期冠状动脉旁路移植术患者左心室长轴收缩功能

目的 探讨超声速度向量成像(VVI)技术评价主动脉瓣置换同期施行冠状动脉旁路移植术(CABG)患者手术前、后左心室长轴收缩功能的价值。 方法 应用Siemens Sequoia 512超声诊断仪及VVI技术,于术前、术后2周及术后3个月对23例主动脉瓣置换同期接受CABG患者(手术组)行超声心动图检查,并对其左心室16节段心肌长轴方向的收缩期平均峰值速度、应变、应变率进行定量分析;选取20名健康查体者作为对照组。 结果 手术组左心室长轴各节段收缩期平均峰值速度、应变和应变率术前组明显低于对照组(P均<0.01),术后2周左心室长轴基底段及中间段收缩期平均速度、应变和应变率较术前减低(P均<0.01),术后3个月各节段平均收缩期速度、应变和应变率较术前明显好转(P均<0.01)。左心室射血分数、短轴缩短率组间差异无统计学意义。 结论 VVI技术能较常规超声技术更加客观、敏感地评价主动脉瓣置换同期CABG术后患者心功能的变化。     

斑点追踪技术观察心肌缺血患者左心室心肌力学改变

目的 探讨二维超声斑点追踪显像(STI)技术评价心肌缺血患者力学改变的应用价值。方法 70例心肌缺血患者(心肌缺血组)和35名健康志愿者(对照组)分别接受STI检查,采用18节段法采集左心室心肌的纵向、径向及圆周应变峰值、达峰时间,对比两组相应节段的差异;采集左心室短轴基底部和心尖部旋转角度峰值、达峰时间,并计算左心室整体扭转角度峰值、达峰时间;比较两组心尖及心底舒张早期旋转角速度峰值(A-vel及B-vel)。结果 心肌缺血患者各缺血节段纵向、径向及圆周应变峰值均较对照组减低,且达峰时间均明显延迟,除后壁纵向应变外,差异均有统计学意义(P均<0.05);心肌缺血患者左心室基底部、心尖部旋转角度峰值及左心室整体扭转角度峰值与对照组比较均减低,且达峰时间均延迟,差异均有统计学意义(P均<0.05);心肌缺血组A-vel明显低于对照组(P<0.05);而B-vel两组差异无统计学意义(P＞0.05)。结论 STI能定量检测心肌缺血患者的左心室多方力学改变,评价心肌局部功能。     

三维斑点追踪成像评价2型糖尿病患者左心室应变

目的 应用三维斑点追踪技术评价2型糖尿病(DM)患者左心室应变。方法 对30例2型DM患者(DM组)及30名健康志愿者(对照组)行三维斑点追踪成像,比较两组左心室整体及各节段应变。结果 DM组左心室收缩期整体应变(GS)、整体环向应变(GCS)、整体径向应变(GRS)及整体纵向应变(GLS)均低于对照组(t=2.18、3.27、2.05、3.76,P均<0.05)。DM组左心室前壁及侧壁环向收缩期峰值应变均低于对照组(P均<0.05);前壁基底段、中间段及侧壁径向收缩期峰值应变均低于对照组(P均<0.05);前间隔基底段、前壁基底段和中间段、侧壁中间段和心尖段、下壁心尖段纵向收缩期峰值应变均低于对照组(P均<0.05)。DM组基底段径向及纵向收缩期峰值应变均低于心尖段,中间段纵向收缩期峰值应变低于心尖段(P均<0.05)。对照组基底段环向、径向及纵向收缩期峰值应变均低于心尖段,中间段纵向收缩期峰值应变低于心尖段(P均<0.05)。结论 三维斑点追踪技术可用以评价2型DM左心室整体及节段收缩功能的早期改变。     

三维斑点追踪成像技术评价不同左心室构型高血压患者左心室收缩功能

目的 探讨三维斑点追踪成像(3D-STI)技术评价不同左心室构型高血压患者左心室收缩功能的价值。方法 随机抽取原发性高血压患者90例和30名健康志愿者(N组),根据Ganan分类方法将原发性高血压患者分为正常构型组40例(Ⅰ组)、向心性重构组20例(Ⅱ组)、向心性肥厚组15例(Ⅲ组)及离心性肥厚组15例(Ⅳ组)。采用3D-STI技术获取左心室整体纵向收缩期峰值应变(GLS)、径向收缩期峰值应变(GRS)、圆周收缩期峰值应变(GCS)、面积收缩期峰值应变(GAS)及左心室射血分数(LVEF),并分析各组间参数的变化规律。结果 GAS随着左心室重构程度加重呈逐渐递减趋势(P<0.05),Ⅰ组GAS峰值小于N组(P<0.05);Ⅱ、Ⅲ组GLS峰值低于N、Ⅰ组(P<0.05);Ⅱ组GRS峰值高于其余各组(P<0.05);Ⅳ组GLS、GRS、GCS、GAS峰值均低于其余各组(P<0.05)。左心室GLS、GCS、GAS、GRS与LVEF相关(r=-0.42、-0.50、-0.58、0.41,P均<0.05)。结论 3D-STI技术为分析不同左心室构型高血压患者的心肌形变提供了新方法。     

超声斑点追踪技术评价手足口病患儿左心室局部收缩功能

目的 应用二维斑点追踪技术评价重症手足口病患儿左心室局部收缩功能。 方法 收集危重症手足口病患儿28例(重症组)、轻症手足口病患儿30例(轻症组)、同期年龄及性别匹配体检儿童30名(对照组)。应用二维斑点追踪技术检测重症组、轻症组及对照组左心室17个节段的收缩期长轴峰值应变、双平面Simpson法检测左心室射血分数,比较重症组、轻症组与对照组临床及血清学检查结果。 结果 重症组心率增快,白细胞总数、血糖及肌酸磷酸激酶心肌同工酶升高,左心室射血分数减低,与轻症组及对照组比较差异有统计学意义(P＜0.05);轻症组仅见下壁基底段及中间段收缩期峰值应变减低,与对照组比较差异有统计学意义(P＜0.05);重症组左心室后壁基底段及中间段、侧壁中间段收缩期峰值应变减低,与轻症组及对照组比较差异有统计学意义(P＜0.05);侧壁基底段收缩期峰值应变减低,与轻症组及对照组比较差异有统计学意义(P＜0.01);侧壁心尖段收缩期峰值应变减低,与对照组比较差异有统计学意义(P＜0.05)。 结论 重症手足口病患儿存在明显局部及整体收缩功能减低。轻症手足口病患儿尽管整体收缩功能正常,但可见个别节段局部收缩功能异常。超声斑点追踪技术可检测左心室局部收缩功能,可为轻症患儿的心脏受累的早期诊断及重症手足口病患儿病情进展和预后评价提供帮助。     

三维斑点追踪成像技术评价不同年龄正常成人左心室整体应变

目的 应用三维斑点追踪成像技术(3D-STI)探讨不同年龄正常成人左心室心肌纵向、径向、圆周应变及面积追踪特征,并探讨其与年龄的关系。方法 将153名健康志愿者按年龄分为青年组(年龄18~45岁,n=54)、中年组(年龄46~64岁,n=51)和老年组(年龄≥65岁,n=48),行常规超声心动图检查,获取一般资料,然后采集心尖四腔切面动态二维图像,获得左心室全容积图像,存储图像并应用3DT分析软件在线分析。结果 与青年组和中年组比较,老年组整体纵向应变、整体径向应变、整体圆周应变和整体面积追踪明显减低(P均<0.05);青年组与中年组整体纵向应变、整体径向应变、整体圆周应变差异均无统计学意义(P均>0.05),而中年组整体面积追踪低于青年组(P<0.05)。左心室16节段分析示青年组纵向峰值应变、径向峰值应变和峰值面积追踪从二尖瓣至心尖水平逐渐减低,圆周峰值应变逐渐增大;中年组纵向峰值应变、径向峰值应变、圆周峰值应变及峰值面积追踪均从二尖瓣至心尖水平逐渐减低;老年组纵向峰值应变、径向峰值应变、圆周峰值应变及峰值面积追踪在乳头肌水平最小,而在二尖瓣水平最大。结论 随着年龄增长,左心室心肌纵向、径向、圆周应变及面积追踪有降低趋势。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.     

Evidence-Based Pain Management and Palliative Care in Issue Four for 2009 of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly. Issue 4 for 2009 contains 4027 complete reviews, 1906 protocols for reviews in production, and 11447 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 600,000 randomized controlled trials, and 12,200 cited papers in the Cochrane methodology register. The health technology assessment database contains over 7500 citations. This edition of the Library contains 90 new reviews, of which 19 have potential relevance for practitioners in pain and palliative medicine.     

Wie zuverlässig sind Angaben zu nichtentzündlichen ausgedehnten Schmerzen?

ZusammenfassungFragestellung Es wurde geprüft, wie sich der Differenziertheitsgrad zweier Schmerzmessmethoden auf Angaben zur Ausgedehntheit klinischer Schmerzen auswirkt. Zugleich wurde der Referenzzeitraum variiert, über den die Patienten berichten sollten.Methode Erfasst wurde der Einfluss zu Lasten der Befragungsdifferenziertheit durch den Vergleich zweier Körperschema-Bildvorlagen. Drei Referenzzeiträume (Schmerz aktuell, letzte Woche, letztes halbes Jahr) wurden vorgegeben.Ergebnisse Patienten mit ausgedehnten Schmerzen gaben bei differenzierter Befragung um so mehr Schmerzen an, je weiter die Schmerzen zurück lagen und je größer der Berichtszeitraum war. Patienten mit gelenknahen Schmerzen gaben bei hoch differenzierter Befragung weniger ausgedehnte Schmerzen in der Vergangenheit an als bei globaler Einschätzung. Patienten mit Rückenschmerzen berichteten bei differenzierter Befragung zum aktuellen Schmerz über weniger ausgedehnte Schmerzen als bei globaler Befragung.Schlussfolgerung Die Angaben zur Schmerzausdehnung variieren vor allem bei Patienten mit ausgedehnten Schmerzen in Abhängigkeit von der Differenziertheit der Befragung. In diesen Fällen ist die Wahrscheinlichkeit erhöht, dass sich die Beschwerdesymptomatik zumindest teilweise erst in der Reaktion auf die situativen Befragungsbedingungen konstituiert und daher nicht auf andere Befragungsbedingungen generalisiert werden kann.