中国男性前列腺癌MRS体素诊断标准

目的 以六分区为基础,研究中国人前列腺外周带癌的1H-MRS体素诊断标准.方法 76例接受前列腺MR和1H-MRS检查的患者纳入研究,其中前列腺外周带癌42例,非前列腺癌34例.以超声引导下穿刺活检作为六分区病理诊断依据.利用患者癌区和非癌区可用体素的(Cho+Cre)/Cit比值描绘ROC曲线,通过寻找最佳临界点确定前列腺癌阳性体素1H-MRS诊断标准.结果 ①癌区体素(Cho+Cre)/Cit比值范围0.395～7.998,平均2.14±1.14;非癌区体素(Cho+Cre)/Cit比值范围0.121～3.537,平均0.83±0.45,两者差异有统计学意义.②根据ROC曲线确定前列腺外周带癌1H-MRS诊断标准:包括D期癌在内时,(Cho+Cre)/Cit≥1.09为阳性体素标准,此时敏感性为85.39%,特异性为81.95%,准确性为83.77%;不包括D期癌时,(Cho+Cre)/Cit≥0.94为阳性体素标准,此时敏感性为64.74%,特异性为81.70%,准确性为76.86%.③炎症可以造成(Cho+Cre)/Cit的升高,使诊断特异性下降.结论 通过制定MRS阳性体素诊断标准,1H-MRS有助于初步诊断前列腺外周带癌.     

前列腺癌和前列腺增生的MRI和MRS诊断与鉴别诊断

目的探讨磁共振成像(MRI)和磁共振波谱分析(MRS)对前列腺病变的诊断与鉴别诊断价值。方法回顾性分析30例前列腺病变,其中前列腺癌(Pca)11例,前列腺增生(BPH)19例,对其MRI和MRS影像学表现进行了研究。MRI平扫观察前列腺病变的位置、大小、形态及信号特点,MRS可观察枸橼酸盐(Cit)和胆碱复合物(Cho)、肌酸(Cre)的波峰及化学位移,并测定(Cho Cre)．Cit值。结果11例PCa在T2 WI图像上表现为外周带的信号减低,其中7例为单侧局灶性,4例为双侧弥漫性; 19例BPH在T2 WI上均显示前列腺移行带和中央带的增大,其中13例表现为局灶性结节状高、低信号,6例表现为弥漫性体积增大,呈均匀低、等信号。MRS显示PCa的Cit峰明显下降,Cho峰升高,(Cho Cre)．Cit值降低,而BPH病灶各代谢物波峰变化不明显,两者间(Cho Cre)．Cit值有显著性差异(P＜0．05)。结论常规MRI与MRS的联合应用有利于提高PCa和BPH的诊断与鉴别诊断正确率。     

前列腺癌和前列腺增生3DMRS的对比研究

目的：分析前列腺癌（PCa）的磁共振波谱成像（MR spectroscopy，MRS）代谢特征，探讨MRS在PCa诊断中的价值。材料与方法：分析经手术或穿刺活检证实的28例PCa和36例前列腺增生（BPH）患者的临床资料及MRI、MRS所见。MRI分析前列腺的大小、形态、病变位置、信号特点和肿瘤侵犯程度等。MRS测量枸橼酸盐（Cit）、胆碱（Cho）、肌酸（Cr）的峰值、（胆碱＋肌酸）／63橼酸盐[（Cho＋Cr）／Cit]的比值。结果：PCa中有22例在BWI像上有明显的PCa征象，其中18例侵犯精囊，14例侵犯膀胱，13例侵犯盆腔周围骨组织，5例侵犯直肠，5例盆腔内见多个肿大淋巴结并部分相互融合成团；余6例未见明显的PCa征象。MRS上将前列腺分成6个区，在MRS代谢图上标记出癌点归入相应分区。每例取4个体素（癌点或MRI上疑点），64例中一共取256个体素进行测量，PCaCit峰值均明显下降，Cho峰值均升高，标记出手术或穿刺活检取材癌区的（Cho＋Cr）／Cit平均值为2．3612±1．91178，增生的波谱形态和癌相反，（Cho＋Cr）／Cit平均值为0．6290±0．59067，两组间差异有统计学意义（t=-4．626，P=0．000〈0．05）。结论：MRI能对PCa定位，了解侵犯部位及转移情况。MRS能根据MRI提示的病变及可疑部位进行定量分析、显示其代谢情况。MRS在MRI形态的基础上能提高对肿瘤的定性诊断，具有重要的诊断价值。     

DWI联合MRS对前列腺癌诊断的价值

目的探讨联合磁共振扩散加权成像(DWI)及磁共振波谱分析(MRS)对前列腺癌(PCa)的诊断价值。材料与方法对经过病理证实的24例PCa和30例前列腺增生(BPH)患者进行DWI和MRS检查。测量PCa区和BPH患者外周带、中央腺体的ADC值,观察枸橼酸盐(Cit)、胆碱(Cho)、肌酸(Cr)的化学位移并测量(Cho+Cr)/Cit比值。分别将PCa区ADC值95%可信区间上界、(Cho+Cr)/Cit值95%可信区间上界作为鉴别PCa与BPH的阈值。分析DWI、MRS及DWI联合MRS三种检查方法对PCa诊断的敏感度、特异度、准确度。结果 PCa区、BPH患者外周带、中央腺体的平均ADC值分别为(0.83±0.12)×10–3 mm2/s、(1.82±0.26)×10–3 mm2/s、(1.46±0.16)×10–3 mm2/s(F=31.1,P0.05),两两间比较差异均有统计学意义(P值均0.05)。PCa区、BPH患者外周带、中央腺体的平均(Cho+Cr)/Cit值分别为1.55±0.11、0.53±0.16、0.64±0.13(F=18.2,P0.05)。PCa区与BPH患者外周带及中央腺体(Cho+Cr)/Cit差异有统计学意义(P0.05),BPH患者外周带与中央腺体(Cho+Cr)/Cit差异无统计学意义(P0.05)。DWI诊断PCa的敏感度、特异度、准确度分比为79.17%、80%、79.63%。MRS诊断PCa的敏感度、特异度、准确度分比为87.5%、86.67%、87.03%。DWI联合MRS诊断PCa的敏感度、特异度、准确度分别为91.67%、93.33%、92.59%。结论 DWI联合MRS对PCa诊断优于单独运用DWI及MRS。     

体外线圈行前列腺磁共振波谱检查在高龄患者中的应用

目的 探讨适合于高龄患者的简便、高效、无创性前列腺磁共振波谱(MRS)检查方法.方法 40 例临床可疑前列腺癌的患者(平均年龄76 岁),在3 T 场强下采用体外线圈行前列腺MRI 和前列腺多体素质子磁共振波谱(1 HMRS)检查.以系统穿刺活检病理诊断为标准,计算并比较前列腺正常外周带、外周带病变、前列腺增生及内腺癌灶的(胆碱+肌酸)/枸橼酸盐[(Cho +Cre)/Cit]比值.结果 40 例疑似患者均顺利完成检查.其中前列腺增生15 例,前列腺癌18 例,不典型增生2 例,前列腺上皮内瘤2 例,前列腺炎2 例,前列腺结核1 例.前列腺外周带癌、不典型增生与前列腺炎及前列腺结核单凭MRI 很难鉴别;但MRS 表现有助于鉴别诊断,前列腺癌、不典型增生及前列腺上皮内瘤(Cho +Cre)/Cit 增高,与正常外周带差异有统计学意义(P ＜0.01),前列腺炎及(Cho +Cre) /Cit 与正常外周带差异无统计学意义.前列腺结核(Cho +Cre) /Cit 较正常外周带下降.以间质增生为主的前列腺增生需注意与发生在内腺的前列腺癌鉴别,但内腺癌MRI 病灶周围无低信号环围绕,且内腺癌(Cho +Cre)/Cit 比值高于前列腺增生,二者间差异有统计学意义(P ＜0.01).结论 用体外线圈行MRS检查简便、高效、无创,对前列腺疾病有鉴别诊断作用,尤其适合高龄前列腺疾病患者.     

中国正常成年男性前列腺的MRS定量分析

目的用磁共振波谱分析方法定量测量中国正常成年男性前列腺的代谢水平. 方法 10例20～40岁的成年男性,临床无前列腺疾病的征象.在前列腺的中央带和外周带、右侧和左侧的底部、中间和尖部各取一兴趣区,共12个兴趣区,测量其(胆碱+肌酸)/枸椽酸盐[(Choline+Creatine)/Citrate,(Cho+Cre)/Cit]的比值. 结果 10例正常前列腺中央带各区(Cho+Cre)/Cit比值之间无显著性差异(P>0.05),平均为0.75±0.33;外周带各区(Cho+Cre)/Cit比值之间无显著性差异(P>0.05),平均为0.51±0.20.前列腺中央带与外周带之间的(Cho+Cre)/Cit比值有显著性差异(P<0.01). 结论正常成年男性前列腺的代谢情况可用MRS来定量评价,前列腺中央带和外周带的代谢水平不同.     

前列腺癌1H-MRSI特征与细胞增殖水平的相关性

目的 分析前列腺癌(PCa)磁共振波谱成像特征与细胞密度及增殖细胞核抗原(PCNA)表达的相关性,探讨1H-MRSI评估PCa细胞增殖状态的价值.方法 资料齐全的PCa患者38例,采用1.5T高场强超导MR成像仪,腹部相控阵线圈,3D-1H-MRSI 采用CSI-3D-Prostate序列扫描.根据常规HE染色和免疫组化观察PCa细胞密度及PCNA表达情况.结果 PCa和正常外周带的(Cho+Cr)/Cit比值分别为3.98±0.12 和0.38±0.09,差异有统计学意义(P<0.05),前列腺癌(Cho+Cr)/Cit比值与细胞密度、PCNA及Gleason分级存在正相关(r=0.495、0.582、0.431,P<0.05).结论 前列腺癌(Cho+Cr)/Cit比值高低与细胞增殖状态有关,1H-MRSI能对前列腺癌细胞增殖状况进行评估.     

良性前列腺增生的MRS与血清PSA、PSAD 相关性初步研究

目的分析良性前列腺增生患者的MRS特征与血清PSA浓度及PSAD的相关性.方法 18例超声引导下穿刺活检证实的良性前列腺增生病人,在中央区设定兴趣区后利用3D MRS测定各兴趣区(Cho Cre)/Cit的比值,计算出每位患者中央区(Cho Cre)/Cit比值的平均值,与其血清PSA浓度及PSAD进行相关性分析.结果 (Cho Cre)/Cit比值和血清PSA浓度呈负相关关系(r＝-0.140),无统计学意义(P＝0.581＞0.05),与PSAD也呈负相关关系(r＝-0.494),有统计学意义(P＝0.037＜0.05).结论 (Cho Cre)/Cit比值较低的BPH患者往往伴有较高的PSAD,通过两者结合提高前列腺疾病诊断的准确性是有可能的.     

用MRS评价前列腺癌内分泌治疗后的代谢变化：癌区与非癌区外周带的比较

目的用MRS定量评价前列腺癌内分泌治疗后的代谢变化,观察癌组织与非癌区外周带的代谢差别.方法 21例内分泌治疗后的前列腺癌患者与19例未经任何治疗的前列腺癌患者,行MRS检查.将前列腺分为左、右两侧,每侧由上到下分为底部、中部和尖部三部分,共六分区.根据手术或穿刺病理结果将这六分区归类为癌区和非癌区.在MRS代谢图上测量前列腺癌区和非癌区外周带内分泌治疗后的胆碱(choline,Cho)、肌酸(creatine,Cre)和枸橼酸盐(citrate,Cit)的代谢水平.结果内分泌治疗后前列腺的Cho、Cre和Cit均下降,Cit下降较明显(P<0.01).内分泌治疗组非癌区(Cho Cre)/Cit的比值高于未治疗组(分别为0.82±0.12和0.59±0.20),差异有统计学意义(P<0.01).内分泌治疗组有Cho,Cre和Cit代谢的癌区(Cho Cre)/Cit的比值与未治疗组相比差异无显著性(分别为2.62±0.31和2.26±0.73,P>0.05).结论 MRS可以定量分析前列腺癌内分泌治疗后的代谢变化,前列腺内分泌治疗后癌区与非癌区外周带的代谢改变不同.     

前列腺3D 1H-MRSI:体线圈与直肠内线圈谱线质量对照

目的 比较前列腺体线圈(BODY)与直肠内线圈(ERC)3D 1H-MRSI的谱线质量,探讨BODY MRS临床应用的可行性.方法 40例前列腺疾病患者,最终获得可测量的BODY与ERC MRS数据者30例.在MRS上将前列腺中央腺体和外周带左、右侧分为底部、中部及尖部,共12个兴趣区;对比BODY和ERC MRSI的各区对应体素的信噪比(SNR)、脂峰强度、(Cho+Cre)/Cit比值.结果 ①SNR:前列腺外周带的底部、中部及尖部左、右侧的SNR,BODY与ERC比较差异均有统计学意义(P均<0.05),均为SNRERC>SNRBODY;中央腺体底部左、右侧的SNR,BODY与ERC比较差异有统计学意义(P均<0.05),均为SNRBODY>SNRERC;②脂峰强度:前列腺外周带底部的左、右侧及尖部左侧脂峰强度两种线圈比较差异有统计学意义(P均<0.05),ERC>BODY;前列腺中央腺体底部左、右侧及中部左侧脂峰强度两种线圈比较差异有统计学意义(P均<0.05),均为ERC>BODY;③MRS各区体素(Cho+Cre)/Cit比值差异无统计学意义.结论 前列腺BODY 3D 1H MRS总体谱线质量能够接受,虽然波谱的SNR略低于直肠内线圈,但其谱线受脂峰影响较小.     

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.     

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.     

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.     

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.